In Myelodysplastic/Myeloproliferative Neoplasms Aberrant Antigen Expression As Assessed by Multiparameter Flow Cytometry Is Related to Molecular Genetic Mutations

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 5152-5152
Author(s):  
Wolfgang Kern ◽  
Susanne Schnittger ◽  
Tamara Alpermann ◽  
Claudia Haferlach ◽  
Torsten Haferlach
Keyword(s):  
Myeloproliferative Neoplasms ◽  
Molecular Genetic ◽  
Antigen Expression ◽  
Multiparameter Flow Cytometry ◽  
Employment Equity ◽  
Aberrant Expression ◽  
Equity Ownership ◽  
Diagnostic Work ◽  
Work Up ◽  
Diagnostic Work Up

Abstract Abstract 5152 Background: Immunophenotyping by multiparameter flow cytometry (MFC) is increasingly used in the diagnostic work-up of patients with cytopenias and suspected myelodysplastic syndromes (MDS). Myelodysplastic/myeloproliferative neoplasms (MDS/MPN) comprise a group of diseases with some features of MDS and is separately classified in the current WHO system. While the immunophenotype of chronic myelomonocytic leukemia has been described in detail, data is scarce on the use of MFC in myelodysplastic/myeloproliferative neoplasms, unclassifiable (MDS/MPNu) as well as on refractory anemia with ring sideroblasts and thrombocytosis (RARS-T), which is a provisional entity in the current WHO classification. Aim: To assess patients with MDS/MPNu and RARS-T for MDS-related aberrant immunophenotypes in the context of a comprehensive diagnostic work-up including cytomorphology, cytogenetics, and molecular genetics. Patients and Methods: A total of 91 patients were analyzed in parallel by cytomorphology, cytogenetics, and MFC applying an antibody panel designed to diagnose MDS. MFC was used to detect expression of mature antigens in myeloid progenitors; abnormal CD13-CD16- and CD11b-CD16-expression patterns, aberrant expression of myeloid markers and reduced side scatter signal in granulocytes; reduced expression of myelomonocytic markers in monocytes; aberrant expression of CD71 in erythroid cells; as well as expression of lymphoid markers in all myeloid cell lines. In 77/91 patients molecular genetic markers were investigated. The median age of the patients was 75.1 years (range, 35.3–87.4). The male/female ratio was 60/31. Six patients had RARS-T and 85 had MDS/MPNu. Results: In 54/91 (59.3%) patients MFC identified an MDS-immunophenotype. This was true in 4/6 (66.7%) RARS-T and in 50/85 (58.8%) MDS/MPNu (n.s.). Cases with MDS-immunophenotype displayed aberrancies significantly more frequently than those without as follows: in myeloid progenitor cells (number of aberrantly expressed antigens, mean±SD: 0.5±0.6 vs. 0.2±0.4, p=0.002), granulocytes (2.7±1.3 vs. 1.2±1.1, p<0.001), and monocytes (1.7±1.2 vs. 0.5±0.7, p<0.001). Accordingly, there was a significant difference in the total number of aberrantly expressed antigens (4.9±2.4 vs. 2.0±1.4, p<0.001). The presence of an aberrant karyotype was not related to an MDS-immunophenotype which was observed in 11/18 (61.1%) cases with aberrant karyotype and in 43/73 (58.9%) with normal karyotype (n.s.). Mutations in RUNX1 and TET2 as well as FLT3-ITD were predominantly present in cases with an MDS-immunophenotype (10/33, 30.3%) and occurred less frequently in cases without (1/7, 9.1%, n.s.). In detail, RUNX1 mutations were present in 4/26 (10.3%) vs. 0/2, TET2 mutations were present in 4/6 (66.7%) vs. 1/2 (50%), and FLT3-ITD was present in 3/29 (10.3%) vs. 0/5. Accordingly, in cases with RUNX1 or TET2 mutations or with FLT3-ITD a significantly higher number of aberrantly expressed antigens was observed as compared to cases with none of these mutations (mean±SD, 6.4±2.0 vs. 4.4±2.5, p=0.024). In contrast, JAK2V617F mutations occurred at identical frequencies in patients with and without MDS-immunophenotype (11/38, 28.9% vs. 9/31, 29.0%). Regarding prognosis, the presence of an MDS-immunophenotype had no impact on overall survival. Conclusions: These data demonstrates that MDS-related aberrant antigen expression is present in the majority of patients with RARS-T and MDS/MPNu. While there is no association between the presence of an MDS-immunophenotype and the detection of JAK2 mutations cases with an MDS-immunophenotype tended to more frequently carry mutations in RUNX1 and TET2 as well as FLT3-ITDs. These data therefore suggests that MDS/MPNu may be subdivided based on molecular genetics and on the immunophenotype into cases with MDS-related features and those without. Further analyses are needed to validate these findings and their potential significance in RARS-T. Disclosures: Kern: MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Schnittger:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Alpermann:MLL Munich Leukemia Laboratory: Employment. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership.

Use Of Flow Cytometry To Identify Myelodysplasia In Peripheral Blood

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 2774-2774
Author(s):  
Wolfgang Kern ◽  
Richard Schabath ◽  
Tamara Alpermann ◽  
Claudia Haferlach ◽  
Susanne Schnittger ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Peripheral Blood ◽  
Antigen Expression ◽  
Employment Equity ◽  
Aberrant Expression ◽  
Equity Ownership ◽  
Diagnostic Work ◽  
Work Up ◽  
Diagnostic Work Up

Abstract Background Flow cytometry (FC) is increasingly used in diagnostic work-up of bone marrow (BM) from patients with suspected or proven myelodysplastic syndrome (MDS). Data on FC in peripheral blood (PB) is scarce. Aims Evaluate the use of FC for PB in suspected or proven MDS by comparison to BM analyzed during follow-up. Methods PB of 157 patients (pts) with suspected MDS was analyzed by FC applying ELN criteria defined recently for diagnosis of MDS in BM (Westers et al., Leukemia 2012). For all pts during follow-up at least one BM sample was evaluable by morphology, cytogenetics, and FC in parallel to confirm or exclude MDS (according to WHO 2008 criteria). Pts were then grouped according to results obtained from BM analysis during follow-up time points into 1) proven MDS (n=96), 2) no MDS (n=32), and 3) MPN, MDS/MPN, or “MDS possible” (presence of dysplastic features by morphology but not sufficient to diagnose MDS) (n=29) (median time to MDS confirmation, 0.9 months, range, 0.1-53.0; median time to last BM assessment without confirmation of MDS; 0.8 months, range, 0.2-23.0). Results First, results of FC on PB were compared between pts with finally proven MDS (n=96) by BM vs. those with no MDS by BM as diagnosed during follow-up. All 34 pts with myeloid progenitor cells (MPC) by FC in PB had finally proven MDS. However, in addition 62/94 (66.0%) of those without MPC (p<0.0001) also had proven MDS. Thus, the presence of MPC in PB was at least strongly indicative of MDS while there were also cases with MDS without MPC in PB. Moreover, besides the presence of MPC in PB, 17 of these 34 cases in addition displayed an aberrant antigen expression on MPC. Focusing on granulocytes we first analyzed side-scatter (SSC) signals in granulocytes as ratio of mean SSC signals granulocytes/lymphocytes (G/L). While for BM samples a reduced SSC ratio G/L had been described which reflects hypogranulation, we indeed found similar data for PB with a significantly lower SSC ratio G/L in pts with proven MDS as compared to those without (mean±SD 5.7±1.1 vs. 6.3±1.0, p=0.015). More strict, a mean SSC ratio G/L of 3.9 was found to most specifically identify pts with MDS: all 6 cases with a ratio <3.9 had MDS. Regarding aberrant antigen expression in granulocytes, MDS was more frequently diagnosed among cases with vs. without the following features: aberrant CD11b/CD16 expression pattern (43/46 investigated, 93.5% vs. 53/82, 64.6%; p=0.0002), lack of CD10 expression (37/43, 86.0% vs. 59/85, 69.4%; p=0.052), CD56 expression (19/21, 90.5% vs. 77/107, 72.0%; p=0.098). Cumulating this data, ≥2 aberrantly expressed antigens on granulocytes were found indicative of MDS: 42/45 (93.3%) of pts with aberrant expression of ≥2 antigens had MDS while only 54/83 (65.1%) of those with 0 or 1 aberrantly expressed antigen had finally proven MDS (p=0.0003). Regarding aberrant antigen expression in monocytes, pts with the following features more frequently had MDS as compared to those without: reduced expression of HLA-DR, CD13, CD11b, or CD15, aberrant expression of CD2 or CD34 (as single makers all n.s.). However, cumulating this data also resulted in a significant relation to a diagnosis of MDS during follow-up: 31/36 (86.1%) of pts with aberrant expression of ≥2 antigens on monocytes were diagnosed MDS vs. 65/92 (70.7%) of those without (p=0.052). Integrating the data for the different cell compartments, pts were separated according to the presence of the following 4 criteria: 1) presence of MPC in PB by FC, 2) aberrant expression of ≥1 antigen in MPC in PB, 3) aberrant expression of ≥2 antigens in granulocytes in PB, and 4) aberrant expression of ≥2 antigens in monocytes in PB: 68/76 (89.5%) of pts with ≥1 of these criteria had MDS, which was the case in 28/52 (53.8%) of cases fulfilling none of these criteria (p<0.0001). Strengthening the selection to presence of ≥2 of the criteria, all such 36 cases had MDS which was true for 60/92 (65.2%) of those with ≤1 criterion (p<0.0001). Applying these criteria to the set of remaining 29 pts with MPN, MDS/MPN, or possible MDS, 17 (58.6%) of them fulfilled ≥1 criterion which was true for 8/32 (25.0%) of pts not diagnosed MDS (p=0.010). Conclusions FC reveals MDS-related findings in PB samples using a specific panel targeting 10 antigens and may be used to identify pts with a high probability of MDS. Further studies with direct comparison of PB and BM should clarify the role of PB analysis by FC in the diagnostic work-up of pts with suspected MDS. Disclosures: Kern: MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Schabath:MLL Munich Leukemia Laboratory: Employment. Alpermann:MLL Munich Leukemia Laboratory: Employment. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Schnittger:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership.

High-Throughput Sequencing to Identify Cytogenetic and Molecular Genetic Aberrations in 24 AML Exomes

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 2389-2389
Author(s):  
Sonja Althammer ◽  
Andreia de Albuquerque ◽  
Niroshan Nadarajah ◽  
Manja Meggendorfer ◽  
Susanne Schnittger ◽  
...  
Keyword(s):  
Copy Number ◽  
Research Funding ◽  
Framework Programme ◽  
Employment Equity ◽  
Seventh Framework Programme ◽  
Equity Ownership ◽  
Diagnostic Work ◽  
Gains And Losses ◽  
Work Up ◽  
Diagnostic Work Up

Abstract Introduction: In acute myeloid leukemia (AML), the karyotype and the molecular mutation profile are the strongest parameters for classification and prognostication. Yet, diagnostic analyses rely on chromosome analysis and sequencing of a constantly growing number of genes. Aim: To evaluate whether whole exome sequencing (WES) can reliably identify copy number states and molecular mutations in a single-step procedure. Patients and Methods: The cohort included 24 AML with an aberrant karyotype at initial diagnosis (ID) who achieved cytogenetic remission (CR) after chemotherapy. Patients showed complex karyotype (n=6), 11q23/MLL-rearrangement (n=4), t(15;17)(q24;q21) (n=4), inv(16)(p13q22) (n=4), t(8;21)(q22;q22) (n=3), and 3q26/EVI1-rearrangement (n=3). For WES DNA was extracted from bone marrow and treated with the TruSeq Exome enrichment kit targeting 201,071 exons. 2x100 bp paired-end sequencing was performed on an Illumina HiSeq machine (Illumina, San Diego, CA) at Fasteris (Geneva, Switzerland). After mapping the sequenced reads with Burrows-Wheeler Aligner [Li&Durbin, Bioinformatics, 2009], variants where called with GATK [McKenna et al., Genome Res., 2010] and copy number variations (CNV) were detected by Excavator [Magi et al., 2013, Genome Biol.]. For validation of the detected variants, 21 leukemia related genes were screened by amplicon sequencing (Illumina MiSeq, or Roche 454, Branford, CT). Array-based comparative genomic hybridization (aCGH) using 12x270K microarrays (Roche NimbleGen, Madison, WI) or 4 x 180K microarray slides (Agilent Technologies, Santa Clara, CA) was performed on all samples. We called CNV using default settings as well as fixed thresholds on the probe medians (0.3 for gains and -0.5 for losses on probe medians and at least 10 probes per segment). Results: The targeted regions were covered by 86 reads on average, while 90% of the bases were covered by at least 15 reads. By comparing ID and CR we detected an average of 15 somatic single nucleotide variants and short indels per patient (range 4-25), affecting 303 genes in total, including genes involved in leukemogenesis. After excluding polymorphisms we screened the mutated genes for recurrence among all cases. Four genes were mutated in at least 3 samples: WT1 (n=5), TP53 (n=4), NRAS (n=3) and TNS1 (n=3). Fourteen genes were mutated in 2 samples: ASXL2, DSCAM, GATA2, IDH2, KIT, OR4C5, POU4F1, LOC93432, RPTOR, SMC1A, SYNE2, TET2, TTN and USP9X. Mutations in OR4C5, LOC93432, SYNE2, TTN and USP9X have not been associated with AML yet. They were rated as damaging according to the SIFT algorithm [Ng and Henikoff, Genome Res., 2003]. In a prior diagnostic work-up 21 different genes had been screened and revealed 16 mutations affecting 7 genes. WES identified 14 mutations correctly (the 2 remaining mutations were covered by reads only insufficiently) and did not call any mutation in genes classified as negative in the routine diagnostic work-up. We further compared CNV derived from WES and aCGH in all 24 patients. Gains and losses detected by aCGH involved 2.65 and 1.40 billion bp, respectively. 96% of bp involved in these CNV were also detected by WES. Of the regions in which WES could not reproduce CNV calls, 15% did not contain exons. WES called gains and losses covering in total 2.56 and 1.47 billion bp, respectively. With aCGH we detected 98% of the gains and 86% of the losses. Regions missed by aCGH did show concordant signal that did not pass the fixed thresholds. However, while relaxing the thresholds to default settings, aCGH reproduces 99% of the WES results. Thus, an excellent concordance was observed (R = 0.99, p < 2.2e-16). We further analysed 19 cytogenetically balanced rearrangements that caused 42 breakpoints in affected chromosomes in 17 patients. As most breakpoints occur in non-coding regions, WES in general is limited in detecting these balanced rearrangements. However, short CNV were detected by WES in 10 cases and confirmed by aCGH. Conclusion: WES was capable of delineating molecular mutation profiles and of robustly detecting copy number states in AML at diagnosis. We suggest that WES in combination with multiplex RT-PCR-based techniques for the detection of recurrent fusion transcripts is a promising approach for a future diagnostic work-up for AML classification and prognostication. This project has been funded by the Seventh Framework Programme (FP7/2007-2013) under grant agreement n. 306242. Disclosures Althammer: MLL Munich Leukemia Laboratory: Employment; Seventh Framework Programme (FP7/2007-2013): Research Funding. de Albuquerque:MLL Munich Leukemia Laboratory: Employment; Seventh Framework Programme (FP7/2007-2013): Research Funding. Nadarajah:MLL Munich Leukemia Laboratory: Employment; Seventh Framework Programme (FP7/2007-2013): Research Funding. Meggendorfer:MLL Munich Leukemia Laboratory: Employment; Seventh Framework Programme (FP7/2007-2013): Research Funding. Schnittger:MLL Munich Leukemia Laboratory: Employment, Equity Ownership; Seventh Framework Programme (FP7/2007-2013): Research Funding. Kern:MLL Munich Leukemia Laboratory: Employment, Equity Ownership; Seventh Framework Programme (FP7/2007-2013): Research Funding. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership; Seventh Framework Programme (FP7/2007-2013): Research Funding. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership; Seventh Framework Programme (FP7/2007-2013): Research Funding.

Serial Assessment of Patients with Suspected Myelodysplastic Syndromes: Significance of Flow Cytometric Findings As Validated by Cytomorphology, Cytogenetics, and Molecular Genetics

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 2787-2787
Author(s):  
Wolfgang Kern ◽  
Claudia Haferlach ◽  
Susanne Schnittger ◽  
Tamara Alpermann ◽  
Torsten Haferlach
Keyword(s):  
Myelodysplastic Syndromes ◽  
Molecular Genetic ◽  
Antigen Expression ◽  
Initial Assessment ◽  
Multiparameter Flow Cytometry ◽  
Trisomy 8 ◽  
Employment Equity ◽  
Number Of Patients ◽  
Equity Ownership

Abstract Abstract 2787 Background: Multiparameter flow cytometry (MFC) is capable of detecting aberrant antigen expression related to myelodysplastic syndromes (MDS) and is increasingly applied as a diagnostic tool in patients with cytopenias and suspected MDS. While in the majority of cases concordant diagnostic results between MFC and cytomorphology (CM) are found, the significance of MFC indicating MDS in the absence of a diagnosis of MDS by CM remains to be clarified. Aim: To assess the course of disease in serially analyzed patients with suspected MDS in whom the first evaluation revealed MDS by MFC but not by CM. Patients and Methods: A total of 142 patients were analyzed in parallel by MFC, CM and cytogenetics (CG) for suspected MDS on at least two separate occasions. The median number of assessments amounted to 2 (range 2–6). The median interval between first and last assessment amounted to 9 months (range 1–53). In a subset of the assessments molecular genetic (MG) analyses were performed for the detection of RUNX1 mutations and FLT3-ITD. Results: At the first assessment MFC results indicated MDS in 64/142 (45.1%) patients and revealed no sign of MDS in 33/142 (23.2%) patients. In the remaining 45/142 (31.7%) patients only minor aberrancies of antigen expression were observed by MFC not sufficient to indicate MDS (“possible MDS by MFC”). In 9/142 (6.3%) patients CG revealed an aberrant karyotype and thereby confirmed MDS at the initial assessment. This applied to 1/33 (3.0%) patient with no MDS by MFC, 3/45 (6.7%) patients with possible MDS by MFC, and 5/64 (7.8%) with MDS by MFC (n.s.). Karyotype abnormalities included complex karyotype (n=3), trisomy 8 (n=1), trisomy 21 (n=1), and others (n=4). These proven MDS patients were excluded from further analyses which were thus based on n=133 patients. During follow-up assessments MDS was confirmed by CM, CG or MG in 30/59 (63.8%) patients with MDS by MFC at initial assessment, in 10/42 (21.3%) with “possible MDS” by MFC at initial assessment, and in 7/32 (14.9%) with no MDS by MFC at initial assessment (p=0.004). The respective median intervals between initial assessment and confirmation of MDS by a non-MFC method amounted to 10.8 months (range, 1.7–53.1), 10.3 months (range, 2.4–36.9), and 15.6 months (range, 7.9–44.4). Thus, in a total of 47 patients follow-up assessments revealed MDS by non-MFC methods as follows: n=38 by CM (36 MDS, 2 AML), n=8 by CG (one case each with del(5q), del(11q), del(20q), trisomy 8, and trisomy 4 and three cases other abnormalities) and n=4 by MG (2 RUNX1 mutations, 1 RUNX1 mutation and FLT3-ITD, 1 FLT3-ITD). Notably, in the 7 patients with no MDS by MFC at the initial assessment, in whom follow-up assessments revealed MDS by non-MFC methods, changes in MFC results at follow-up assessments to “possible MDS” (n=4) and MDS (n=2) were observed. The respective figure for the 10 patients with “possible MDS” by MFC at initial assessment, who were confirmed MDS by non-MFC methods during follow-up assessments, is “possible MDS” in 5 patients and MDS in 4 patients during follow-up MFC assessment. Conclusions: This data indicates that diagnostic findings by MFC revealing MDS in the absence of diagnostic findings of MDS by CM are confirmed in the majority of cases during follow-up. Furthermore, the confirmation of MDS during follow-up even in cases with minor aberrancies of antigen expression is higher as compared to cases with no MDS by MFC. There remains, however, a significant number of patients (36.2%) with MDS by MFC which is not confirmed by other methods during follow-up; further clinical evaluation is needed to validate the significance of MFC findings in these cases. Overall, this data argues in favour of a combined approach to diagnose MDS including MFC besides CM, CG and MG, and suggests a closer monitoring of patients with suspected MDS in whom aberrancies are detected by MFC. Disclosures: Kern: MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Schnittger:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Alpermann:MLL Munich Leukemia Laboratory: Employment. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership.

In BCR-ABL1 Negative Myeloproliferative Neoplasms the Detection of JAK2exon12, MPLW515, CBL, KITD816V, FIP1L1-PDGFRA Mutations Are Closely Linked to Specific Entities, Whereas the JAK2V617F, TET2, or EZH2 Mutations Demonstrate a Broader Diversity: Patterns From Diagnostic Reports of 18,547 Patients Analyzed

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 458-458
Author(s):  
Susanne Schnittger, ◽  
Christiane Eder ◽  
Frank Dicker ◽  
Vera Grossmann ◽  
Alexander Kohlmann ◽  
...  
Keyword(s):  
Myeloproliferative Neoplasms ◽  
Hematologic Malignancy ◽  
Rare Event ◽  
Jak2v617f Mutation ◽  
Patient Specific ◽  
Second Step ◽  
Double Positive ◽  
Employment Equity ◽  
Equity Ownership ◽  
Diagnostic Work

Abstract Abstract 458 The first mutation detected in BCR-ABL1 negative myeloproliferative neoplasms (MPN) was JAK2V617F that revolutionized diagnostics of MPN during the last five years. However, although this genetic marker is useful to discriminate MPN from reactive disorders, it is not specific for one entity. In addition, approximately 5% of all polycythemia vera (PV) and 50% of essential thrombocytosis (ET) and primary myelofibrosis (PMF) are not JAK2V617F mutated. In these entities other activating mutations, e.g. MPLW515 mutations or JAK2exon12 mutations, cover additional small proportions of patients without JAK2V617F mutation. To further improve the molecular genetic characterization of MPN research focuses on the identification of novel mutations and, recently, CBL, TET2, and EZH2 genes were identified to be mutated in MPN. We here report on our single centre experience in applying these markers in a daily diagnostic work flow comprizing a total cohort of 18,547 cases with suspected MPN that were investigated between 8/2005 und 8/2010 with individual patient specific combinations of these markers as soon as published. Thus, the most frequently tested marker was JAK2V617F that was applied in 17,027 pts. In 6,622/17,027 (38.9%) a definite diagnosis of MPN could be made or confirmed on the basis of the detection of JAK2V617F mutation. More detailed, the percentage of JAK2V617F positive cases varied depending on the suspected diagnoses: In patients with cytomorphologically confirmed or suspected ET 581/891 (65.2%) were JAK2V617F positive, in PMF: 168/290 (57.9%), in PV: 800/942 (84.9%), in MPN-U: 51/212 (24.0%), in CMML: 38/383 (9.9%), in “MPN” not further specified by the referring physician: 4741/11249 (42.1%), and in those with unexplained leukocytosis/thrombocytosis/splenomegaly or suspected hematologic malignancy: 139/2492 (5.6%). Many of the before mentioned cases were suspected MPN and therefore analyzed for both JAK2V617F and BCR-ABL1. Thus, in 9,924 pts BCR-ABL1 and JAK2V617F testing were performed in parallel. As such, in 541/9,924 (5.5%) analyses BCR-ABL1 positive CML was identified and 3,558 cases were JAK2V617F mutated (35.9%). Only 8 pts were BCR-ABL1/JAK2V617F double positive (0.08%), thus this is a very rare event. In cases with JAK2V617F negative PV in a second step JAK2exon12 mutation was analyzed and 27/147 (18.3%) were tested positive. JAK2V617F negative ET or PMF were analyzed in a second step for MPLW515 mutations. In ET 24/258 (9.3%) and in PMF 14/164 (8.5%) cases were tested positive. JAK2exon12 or MPLW515 were never concomitantly detected with JAK2V617 in our cohort (parallel assessments: n=3,769). PCR for detection of FIP1L1-PDGFRA was performed in 1,086 cases with suspected HES/CEL or unclear eosinophilia but only 26 (2.4%) were tested positive and a CEL could be diagnosed. However, in 36/130 (27.7%) FIP1L1-PDGFRA negative cases a KITD816V mutation was detected and thus a diagnosis of mastocytosis could be established. In addition, confirmation of mastocytosis was achieved in further 326/731 (44.6%) pts with suspected mastocytosis, three of these pts had a JAK2V617F mutation in addition. Further analyses were recently done on selected well characterized cohorts of MPN: CBL mutations were analyzed in 623 cases and tested positive in 54 (8.7%): 26/199 CMML (13.0%), 1/25 PMF, 27/293 MPN-U (9.2%), but never were detected in ET (n=61) or PV (n=45). TET2 sequencing detected mutations in 56/191 (29.3%) of pts analyzed: ET: 6/28 (21.4%), PMF: 4/12 (33.3%), PV: 10/31 (32.3%), CMML: 17/22 (77.3%) cases, MPN-U: 17/86: (19.8%), HES: 1/9 cases, Mastocytosis: 1/3 cases. Thus, TET2 mutations are widely spread in different entities and were frequently associated with other mutations: JAK2V617F: n=16, JAK2exon12: n=1, MPLW515: n=2, CBL: n=5, FIP1L1-PDGFRA: n=1, KITD816V: n=1, and EZH2: n=2. Finally, EZH2 sequence analysis detected mutations in 4/68 (5.9%) cases (1/16 PV, 2/11 PMF, 1/17 MPN-U, 0/20 ET, 0/4 CEL). In conclusion, these data show that the analysis of molecular mutations greatly improved the diagnostic work up of MPN in the last 5 years. The detection of some mutations (JAK2exon12, MPLW515, CBL) are useful to further subclassify MPNs. Others (JAK2V617F, TET2, EZH2) are widely distributed and are helpful for classification and also to discriminate MPN from reactive disorders. The individual power of each marker for prognostication in MPN remains to be defined in future studies. Disclosures: Schnittger: MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Eder:MLL Munich Leukemia Laboratory: Employment. Dicker:MLL Munich Leukemia Laboratory: Employment. Grossmann:MLL Munich Leukemia Laboratory: Employment. Kohlmann:MLL Munich Leukemia Laboratory: Employment. Kern:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership.

Impact of Expression of BAALC, CDKN1B, ERG, EVI1, and MN1 on Prognosis and Their Association with Karyotype, FLT3-ITD, NPM1 and MLL-PTD Status In Adult AML: A Comprehensive Study on 286 Cases

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 953-953
Author(s):  
Claudia Haferlach ◽  
Alexander Kohlmann ◽  
Sonja Schindela ◽  
Tamara Alpermann ◽  
Wolfgang Kern ◽  
...  
Keyword(s):  
Molecular Genetic ◽  
Normal Karyotype ◽  
Genetic Alterations ◽  
Complex Karyotype ◽  
Employment Equity ◽  
Aberrant Expression ◽  
Cox Regression Analysis ◽  
Total Cohort ◽  
Equity Ownership ◽  
Low Expression

Abstract Abstract 953 Introduction: The WHO classification in 2008 listed for the first time aberrant expression of genes as molecular genetic alterations affecting outcome in AML. High expression of BAALC, ERG and MN1 were shown thus far to be associated with unfavorable outcome in normal karyotype AML (AML-NK). In addition high EVI1 expression was suggested to predict poor outcome. Recently, our group identified low expression of CDKN1B as a favorable prognostic marker. The aim of this study was to evaluate the expression of BAALC, CDKN1B, ERG, EVI1 and MN1 in AML comprising all cytogenetic risk groups with respect to their association with distinct cytogenetic and known molecular genetic subgroups and their impact on prognosis. Patients/Methods:: Expression levels of BAALC, CDKN1B, ERG, EVI1 and MN1 were determined by oligonucleotide microarrays (HG-U133 Plus 2.0, Affymetrix) in 286 AML (t(15;17) n=15; t(8;21) n=16; inv(16) n=7; normal karyotype n=99; 11q23/MLL-rearrangements n=10; complex karyotype n=51; other abnormalities n=88). Patients were further analyzed for mutations in NPM1, FLT3-ITD, CEPBA and MLL-PTD. Results: Expression of BAALC, CDKN1B, ERG, EVI1 and MN1 varied significantly between genetic subgroups: While t(15;17), t(8;21) and 11q23/MLL-rearrangements were associated with low CDKN1B expression, AML-NK and NPM+ cases showed a higher CDKN1B expression. Lower BAALC expression was observed in AML with t(15;17), 11q23/MLL-rearrangement and AML-NK as well as in FLT3-ITD+ AML and in NPM1+ AML, while in AML with other abnormalities a higher BAALC expression was observed. ERG expression was lower in AML with 11q23/MLL-rearrangement and normal karyotype, while it was higher in AML with complex karyotype. Low EVI1 expression was observed in AML with t(15;17), t(8;21), inv(16) and AML-NK, while it was higher in AML with 11q23/MLL-rearrangements. Low MN1 expression was associated with t(15;17), t(8;21) and AML-NK, while it was increased in cases with inv(16) or other abnormalities. Next, Cox regression analysis was performed with respect to overall survival (OS) and event free survival (EFS). In the total cohort high BAALC and ERG expression as continuous variables were associated with shorter OS and EFS while CDKN1B, EVI1 and MN1 had no impact. Furthermore the cohort was subdivided into quartiles of expression for each gene. After inspection of the survival curves the cut-off for high vs low expression was set as follows: BAALC: 75th percentile, CDKN1B: 25th percentile, ERG and MN1: 50th percentile. For EVI1 expression pts were separated into expressers (n=44) and non-expressers (n=242). Low CDKN1B expression was associated with longer OS and EFS in the total cohort (p=0.005, not reached (n.r.) vs 14.9 months (mo); p=0.013, 31 vs 9.7 mo). High BAALC expression had no impact on OS, but was associated with shorter EFS in the total cohort as well as in AML with intermediate cytogenetics and AML with other abnormalities (p=0.032, 6.2 vs 13.0 mo; p=0.027, 5.1 vs 11.3 mo; p=0.006, 2.3 vs 14.8 mo). High ERG expression was significantly associated with shorter OS and EFS in the total cohort (p=0.002, 12.5 mo vs n.r.; p=0.001, 8.1 vs 15.7 mo) as well as in AML-NK (p=0.001, 11.3 mo vs n.r.; p=0.010, 7.2 vs 22.1 mo). OS was also shorter in AML with unfavorable karyotype (p=0.048, median OS 9.3 mo vs n. r.). With respect to MN1 high expressers had a significantly shorter OS and EFS in the total cohort (p=0.004, 12.3 mo vs. n.r.; p=0.001, 8.1 vs 16.7 mo) as well as in AML-NK (p=0.001, 9.7 mo vs n.r.; p=0.001, 5.1 vs 22.1 mo). In a multivariate analysis including CDKN1B, ERG and MN1 all parameters retained their impact on OS as well as on EFS, while BAALC lost its impact on EFS. Adding MLL-PTD, NPM1+/FLT3-ITD-, favorable and unfavorable karyotype into the model demonstrated an independent significant adverse impact on OS for MLL-PTD (p=0.027, relative risk (RR): 2.38) and ERG expression (p=0.044, RR: 1.59) only. In the respective analysis for EFS only favorable karyotype showed an independent association (p=0.002, RR: 0.261). Conclusion: 1) Expression of BAALC, CDKN1B, ERG, EVI1 and MN1 varies significantly between cytogenetic subgroups. 2) BAALC as a continuous variable and CDKN1B, ERG and MN1 as dichotomized variables are independently predictive for OS and EFS in AML. 3) ERG expression even retains its independent prediction of shorter OS if cytogenetic and other molecular genetic markers are taken into account. Disclosures: Haferlach: MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Kohlmann:MLL Munich Leukemia Laboratory: Employment. Schindela:MLL Munich Leukemia Laboratory: Employment. Kern:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Schnittger:MLL Munich Leukemia laboratory: Employment, Equity Ownership. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership.

ETV6 Rearrangements Are Recurrent Genetic Events In Myeloid Malignancies and In AML Are Associated with NPM1- and RUNX1-Mutations and An Intermediate Prognosis

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 2758-2758
Author(s):  
Claudia Haferlach ◽  
Susanne Schnittger ◽  
Wolfgang Kern ◽  
Torsten Haferlach
Keyword(s):  
De Novo ◽  
Normal Karyotype ◽  
Employment Equity ◽  
Childhood All ◽  
Myeloid Malignancies ◽  
Equity Ownership ◽  
De Novo Aml ◽  
Diagnostic Work ◽  
Work Up

Abstract Abstract 2758 Introduction: The ETV6 gene (formerly TEL) is located in the chromosomal band 12p13 and is a frequent target of deletions and chromosomal translocations in both myeloid and lymphoid leukemias. In ALL the most frequent partner gene of ETV6 is RUNX1. ALL with ETV6-RUNX1 fusions are observed in 20% of childhood ALL and are associated with favorable outcome. In contrast ETV6 rearrangements are less frequent and not well described in myeloid malignancies. Therefore, the aim of this study was to analyze ETV6 rearrangements in myeloid malignancies with respect to frequency, partner genes and impact on prognosis. Patients/Methods: 55 cases with ETV6 rearrangements were identified in a total cohort of 9,550 cases (0.5%) with myeloid malignancies (de novo AML: n=3,090, s-AML: 486, t-AML: 222, MDS: n=3,375, MDS/MPN overlap: n=210, CMML: n=447, MPN: n=1,720) which had been sent to our laboratory between 08/2005 and 07/2010 for diagnostic work-up. In all cases chromosome banding analysis was performed and in cases with abnormalities involving 12p13 FISH was carried out in addition to verify the ETV6 rearrangement. Results: ETV6 rearrangements were observed in 31 patients with de novo AML (1.0% of investigated cases), 8 with s-AML (1.7%), 5 with t-AML (2.3%), 6 with MDS (0.2%) and 5 with MPN (0.3%). No ETV6 rearrangements were detected in the cohorts of MDS/MPN or CMML. ETV6 rearrangements were significantly more frequent in s-AML and t-AML as compared to de novo AML (p<0.001). Median age in AML was 59.9 years. In 15 cases with de novo AML FAB-subtypes were available: M0: n=8, M1: n=4, M2: n=1, M4: n=1, and M7: n=1. Thus, ETV6 rearrangements are closely related to immature AML subtypes. In 25/55 cases (45.5%) the ETV6 rearrangement was the sole abnormality. Recurrent additional abnormalities were 7q-/-7 in 10 cases and del(5q) in 8 cases. 36 different partners of ETV6 were observed, recurrent partners were located on 3q26 (EVI1, n=11), 5q33 (PDGFRB, n=4), 22q12 (n=3), 2q31 (n=2), 5q31 (ACSL6, n=2), 12p12 (n=2), 17q11 (n=2). Molecular analysis was performed in addition in AML with ETV6 rearrangements for mutations in NPM1 (n=26 investigated), FLT3-ITD (n=33), FLT3-TKD (n=11), MLL-PTD (n=25) and RUNX1 (n=7). NPM1-mutations were observed in 5 cases (19.2%), FLT3-ITD in 3 cases (9.1%), FLT3-TKD in 2 cases (18.2%), MLL-PTD in 1 case (4%) and RUNX1 mutations in 4 cases (57.1%), respectively. Clinical follow-up data was available of 47 cases. No differences in overall survival (OS) and event-free survival (EFS) were observed in cases with ETV6 rearrangement whether or not additional cytogenetic abnormalities or 7q-/-7 or del(5q) were present. Next 30 de novo AML with ETV6 rearrangement were compared to 819 AML without ETV6 rearrangement. Based on cytogenetics cases were assigned into 9 subgroups: 1) t(15;17)(q22;q21), n=48; 2) t(8;21)(q22;q22), n=29; 3) inv(16)(p13q22)/t(16;16)(p13;q22), n=19; 4) 11q23/MLL abnormalities, n=28; 5) inv(3)(q21q26)/t(3;3)(q21;q26), n=6; 6) normal karyotype, n=424; 7) complex karyotype, n=71; 8) other abnormalities, n=194 and 9) ETV6 rearrangements, n=30. Median OS was not reached for groups 1, 2, 3, 4, and 6 and was 10.6 mo, 11.8 mo, 32.2 and 26.3 mo for groups 5, 7, 8, and 9 respectively. OS at 2 yrs was 95.6%, 96.3%, 76.6%, 64.9%, 26.7%, 63.3%, 23.9%, 58.5% and 60.1% for groups 1–9, respectively. The respective data for median EFS were: not reached for groups 1 and 2 and 15.9 mo, 13.5 mo, 5.1 mo, 16.6 mo, 7.5 mo, 12.5 mo and 14.0 mo for groups 3–9, respectively. Conclusions: ETV6 rearrangements are rare in myeloid malignancies. ETV6 is rearranged with a large variety of partner genes. The highest frequency of ETV6 rearrangements was observed in s-AML and t-AML. OS and EFS of AML with ETV6 rearrangements are comparable to AML with normal karyotype. Thus, the detection of ETV6 rearrangements is associated with in intermediate prognosis. Disclosures: Haferlach: MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Schnittger:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Kern:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership.

Multiparameter Flow Cytometry in Patients with Suspected Myelodysplastic Syndromes Adds Significant Prognostic Information: A Study on 1,013 Patients

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 1722-1722
Author(s):  
Wolfgang Kern ◽  
Claudia Haferlach ◽  
Tamara Alpermann ◽  
Susanne Schnittger ◽  
Torsten Haferlach
Keyword(s):  
Flow Cytometry ◽  
Myelodysplastic Syndromes ◽  
Continuous Variable ◽  
The Other ◽  
Multiparameter Flow Cytometry ◽  
Prognostic Information ◽  
Employment Equity ◽  
Aberrant Expression ◽  
Equity Ownership ◽  
Cox Analysis

Abstract Abstract 1722 Backgroundn: Multiparameter flow cytometry (MFC) has been demonstrated capable of identifying aberrant antigen expression related to myelodysplastic syndromes (MDS). The exact role and place of MFC in the diagnostic work-up of patients with suspected MDS, however, remains to be defined. Aim: Evaluation of the diagnostic impact of MFC in relation to cytomorphology (CM) and cytogenetic (CG) by determining the association of MFC results to overall survival (OS). Patients and Methods: In 1,013 patients with suspected MDS bone marrow samples had been analyzed in parallel by MFC, CM, and CG. CM confirmed MDS in 511 patients, excluded MDS in 277 patients, and showed dysplastic features but not sufficient to unequivocally diagnose MDS by CM in 225. The MFC diagnostic result was in agreement with MDS (“MDS by MFC”) in 446 patients including 382/511 patients with MDS proven by CM. CG revealed an aberrant karyotype in 245/1,013 patients. The median follow-up time amounted to 14.8 months, a total of 156 deaths was recorded. Results: The first set of analyses was performed on the cohort of 511 patients with MDS confirmed by CM. The median total number of aberrantly expressed antigens amounted to 3 (range, 0–11) and included expression of mature antigens in myeloid progenitors; abnormal CD13-CD16- and CD11b-CD16-expression patterns, aberrant expression of myeloid markers and reduced side scatter signal (SSC) in granulocytes; reduced expression of myelomonocytic markers in monocytes; aberrant expression of CD71 in erythroid cells; as well as expression of lymphoid markers in all myeloid cell lines. A higher total number of aberrantly expressed antigens as a continuous variable correlated with a shorter OS (Cox analysis, p=0.008). Next, patients were categorized based on the three parameters i) at least 3 aberrantly expressed antigens, ii) significantly reduced SSC in granulocytes, and iii) >5% myeloid progenitor cells in MFC. Patients with at least one of these criteria had a significantly shorter OS than those without (median 48.5 months vs. not reached (n.r.), p<0.001). Overall, the global diagnostic rating of “MDS by MFC” was the strongest MFC parameter: Patients with “MDS by MFC” had a shorter OS as compared to patients without (median 56.8 months vs. n.r., p=0.001). Non-MFC parameters related to OS in univariable Cox analysis included WBC count, thrombocyte count, CG (grouped according to IPSS), % blasts by CM (p<0.001 each), Hb level (p=0.001), and age (p=0.002). In order to determine the clinical relevance of “MDS by MFC” a multivariable analysis for OS was performed on this parameter together with non-MFC parameters (blood counts excluded due to incomplete data sets). It revealed an independent relation between “MDS by MFC” and OS (p=0.045). This was also true for relation of OS to the other parameters (CG, p<0.001; age, p=0.001, % blasts by CM p=0.014). Given this strong prognostic value of “MDS by MFC” in cases with MDS proven by CM a second set of analyses on the relation between MFC findings and OS were performed for the complete cohort of 1,013 patients, i.e. additionally including all cases with a diagnostic result by CM of “no MDS” or “dysplastic features not sufficient to diagnose MDS”. Again, significant relations to OS was found for the total number of aberrantly expressed antigens as a continuous variable (Cox analysis, p<0.001), for at least one of the above mentioned criteria i), ii) or iii) (median 75.6 months vs. n.r., p<0.001), as well as for “MDS by MFC” (median 60.5 months vs. n.r., p<0.001). Again, “MDS by MFC” proved to be the most relevant MFC parameter. Multivariable Cox analysis for OS including “MDS by MFC” and non-MFC parameters revealed a trend only for “MDS by MFC” (p=0.135) and significance for the other parameters (age, p<0.001; CG, p<0.001; blasts by CM, p=0.045). Conclusions: 1) The present data indicates the diagnostic use of MFC for MDS results in independent prognostic information for cases with MDS as proven by CM. 2) Furthermore, the diagnosis of MDS by MFC has a strong prognostic impact even without prove of MDS by CM which strengthens the diagnostic value of MFC even more. 3) This analysis therefore argues in favour of diagnosing MDS not only based on a combination of CM and CG but of adding also MFC for better classification and even prognostication in the future. Disclosures: Kern: MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Alpermann:MLL Munich Leukemia Laboratory: Employment. Schnittger:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership.

A Novel, Highly Sensitive, Rapid, Non-PCR Based Method for the Detection of the JAK2 V617F Mutation in Chronic Myeloproliferative Neoplasms.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 3892-3892
Author(s):  
Giulia Minnucci ◽  
Giulia Amicarelli ◽  
Silvia Salmoiraghi ◽  
Orietta Spinelli ◽  
Daniel Adlerstein ◽  
...  
Keyword(s):  
Myeloproliferative Neoplasms ◽  
Lamp Assay ◽  
Jak2v617f Mutation ◽  
Wild Type ◽  
Molecular Monitoring ◽  
Chronic Myeloproliferative Neoplasms ◽  
Allele Specific ◽  
Diagnostic Work ◽  
Work Up ◽  
Diagnostic Work Up

Abstract Abstract 3892 Poster Board III-828 Background The point mutation G1849T (V617F) of the JAK2 gene occurs at high frequency in several Ph-negative chronic myeloproliferative neoplasms (Ph-neg-CMNs), such as Polycythemia Vera (PV), Essential Thrombocythemia (ET) and Myelofibrosis (MF). The molecular analysis of this mutation is mandatory in the diagnostic work up of these diseases. Several molecular diagnostic techniques are currently used but each of them present some important limitations such as a low sensitivity and the requirement of labor intensive procedures performed with expensive specialized equipment that may not always be readily available in clinical laboratories. Method We have developed a non-PCR method for the identification of the JAK2V617F mutation called Allele Specific (AS)-LAMP, based on the Loop mediated isothermal AMPlification (LAMP) principle (Notomi et al. NAR 2000). LAMP reaction efficiently produces, within one hour, a large amount of amplified DNA and does not require gel separation of the amplified product which is indirectly detected by measuring the loss of intensity of a light beam through the reaction solution in which suspended particles of magnesium pyrophosphate are generated as a result of the DNA amplification process. Pyrophosphate salts produce turbidity which is both visible to the naked-eye and monitorable in Real-Time turbidimetry. AS-LAMP consists of 4 primers suitable for LAMP and a self-annealed primer highly specific for the mutated target sequence. To ensure efficiency and sensitivity a Peptide Nucleic Acid (PNA) probe specific for the wild-type allele was added thus resulting in absence of normal allele amplification within the reaction time. The AS-LAMP assay was optimized on plasmid controls and on human genomic DNA extracted from the HEL and K562 cell lines, respectively carrying or not the JAK2V617F mutation. The level of sensitivity was determined by testing serial dilutions of mutant HEL DNA in K562 DNA at concentrations of 100, 10, 1, 0.5, 0.1, 0.05, 0.01 and 0%. Results This simple, easy to perform and rapid AS-LAMP assay selectively detects the JAK2V617F mutated DNA down to 0.05%. Moreover, when mutant DNA is present in the range of 1%-100% in wild type DNA, we observed a linear relationship between the mutant allele burden and the amplification time. We have validated this AS-LAMP assay on DNA obtained from 87 patient samples previously analyzed by conventional Allele Specific PCR (ASO-PCR): 19 PV, 58 TE, 3 IMF, 1 post ET Acute Myeloid Leukemia (AML), 1 post PV and 1 post ET Myelofibrosis, 2 Idiopathic Erythrocytosis (IE) and 2 unclassified CMNs. All samples which proved positive by ASO-PCR resulted positive with our AS-LAMP assay (100% concordance). In addition, 6 ET and 1 IE previously found negative by ASO-PCR were found to be low-positive (<1%) with AS-LAMP. Interestingly, the molecular monitoring in one patient with post-PV MF achieving complete remission after allogenic transplantation, proved repeatedly negative by ASO-PCR but positive by AS-LAMP. Sequencing analysis after PCR amplification with PNA confirmed the presence of the JAK2V617F mutation in all these LAMP-low-positive samples. None of the negative controls, (1 AML, 2 Acute Lymphoblastic Leukemia, 2 Follicular Non Hodgkin's Lymphoma, 2 Chronic Lymphocytic Leukemia, and 1 healthy donor) gave false positive results. Conclusions This novel, non-PCR based allele-specific LAMP assay is rapid and reduces the risk of contamination related to post amplification manipulations. Most importantly, it is highly specific and sensitive and significantly increases our ability to detect a low JAK2V617F tumor allele burden. For all these reasons, the AS-LAMP assay can be a valid and powerful tool in the routine diagnostic work up and the molecular monitoring of these diseases. Disclosures: Minnucci: Diasorin S.p.A.: Employment. Amicarelli:Diasorin S.p.A: Employment. Salmoiraghi:Diasorin S.p.A.: Consultancy, Honoraria. Spinelli:Diasorin S.p.A: Consultancy, Honoraria. Adlerstein:Diasorin S.p.A.: Employment. Rambaldi:Diasorin S.p.A.: Consultancy, Honoraria.

Significance of Flow Cytometric and Mutational Findings in Patients with Cytopenias and Limited or No Signs of Myelodysplasia By Cytomorphology

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 1671-1671
Author(s):  
Wolfgang Kern ◽  
Manja Meggendorfer ◽  
Claudia Haferlach ◽  
Susanne Schnittger ◽  
Torsten Haferlach
Keyword(s):  
Flow Cytometry ◽  
Normal Karyotype ◽  
Initial Assessment ◽  
Employment Equity ◽  
Initial Flow ◽  
Flow Cytometric ◽  
Equity Ownership ◽  
Diagnostic Work ◽  
Work Up

Abstract Introduction: The diagnosis of myelodysplastic syndromes (MDS) has been clearly defined by the WHO classification but remains a challenge in a significant number of cases with cytomorphologically borderline findings and normal karyotype. Furthermore, flow cytometry is capable of identifying MDS-specific aberrant antigen expression yet its value in these borderline cases as well as in those even without cytomorphologic findings of myelodysplasia remains to be clarified. Follow-up analyses as well as extension of diagnostic work-up to screening for molecular mutations may give further insight. Aims: Assess the significance of cytomorphologically borderline dysplastic changes and of flow cytometric MDS-related findings in the absence of a clear-cut diagnosis of MDS by screening for molecular mutations and by diagnostic reassessment during follow-up. Patients and methods: Bone marrow samples of 322 patients were assessed for suspected MDS by cytomorphology, flow cytometry and cytogenetics in parallel from 08/2005 to 11/2014 which 1) did not reveal a definite diagnosis of MDS by cytomorphology, 2) had a normal karyotype and 3) had at least one follow-up bone marrow assessment. By cytomorphology, 159 (49%) cases had borderline dysplastic findings while 163 (51%) had no sign of MDS. By flow cytometry, 138 (43%) cases had findings in agreement with MDS according to ELN criteria (Westers et al., Leukemia 2012; at least three aberrantly expressed antigens), 141 (44%) had borderline findings (one or two aberrantly expressed antigens) and 43 (13%) had no signs of MDS. A total of 699 follow-up samples were analyzed (median 2/patient). The median follow-up amounted to 3.0 years. In 147/322 patients (46%) screening for molecular mutations was performed on the initial samples, respectively, targeting a total of 20 genes (median 4 genes/patient, range 1-20). Analyzed genes were ASXL1, TET2, RUNX1, SRSF2, BCOR, DNMT3A, IDH2, NPM1, SF3B1, TP53, ZRSR2, CBL, CSF3R, ETV6, KDM6A, KRAS, MLL, SETBP1, SMC3 and U2AF1. Results: A total of 145 patients (45%) were diagnosed with MDS by cytomorphology during follow-up. The median duration until diagnosis amounted to 3.4 years. Regarding initial cytomorphology, more cases with borderline dysplastic findings were diagnosed MDS at follow-up than those without any dysplastic findings (82/159 (52%) vs 63/163 (39%), p=0.025). However, the duration until diagnosis of MDS did not differ significantly between the two groups (median 2.6 vs 3.4 years). Regarding initial flow cytometry, more cases with findings in agreement with MDS were diagnosed MDS by cytomorphology at follow-up than those without (80/138 (58%) vs 65/184 (35%), p<0.001) while there was no difference between cases with one or two aberrantly expressed antigens at initial assessment vs those with none (51/141 (36%) vs 14/43 (33%), n.s.). The duration until diagnosis of MDS significantly differed between the groups as defined by flow cytometry and was shortest in cases in agreement with MDS at initial assessment and longest in those without any aberrantly expressed antigen (median 1.9 vs 4.1 vs 5.6 years, p<0.001). Overall survival (OS) for all cases was 80% at 5 years. While initial cytomorphologic results revealed no impact on OS, patients with an initial flow cytometric result in agreement with MDS tended to have a shorter OS (5 year OS 70% vs 88%, p=0.12). Molecular screening revealed mutations in 21/147 patients (14%) at initial assessment. Mutated genes included ASXL1 (mutated in 6 patients), TET2 (6), RUNX1 (3), SRSF2 (3), as well as 2 cases each for BCOR, DNMT3A, IDH2, NPM1, SF3B1, TP53 and ZRSR2 and 1 case each for CBL, CSF3R, ETV6, KDM6A, KRAS, MLL, SETBP1, SMC3 and U2AF1. The percentage of patients with at least one mutation did not differ between cases with borderline dysplastic findings by cytomorphology as compared to those without any dysplastic findings. In contrast, significantly more cases with findings in agreement with MDS by flow cytometry had at least one mutation as compared to those with one or two aberrantly expressed antigens as well as to those with none (15/71 (21%) vs 6/58 (10%) vs 0/18, p=0.012). Conclusions: This data strongly supports the need to define the role of flow cytometry in the diagnostic work-up in suspected MDS and argues for an integrated approach with cytomorphology and cytogenetics. Implementation also of molecular data on mutations may further improve the validity of MDS diagnostics. Disclosures Kern: MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Meggendorfer:MLL Munich Leukemia Laboratory: Employment. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Schnittger:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership.

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