Clinical Significance of CSF3R, SRSF2 and SETBP1 mutation in Chronic Neutrophilic Leukemia and Chronic Myelomonocytic Leukemia

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 1617-1617
Author(s):  
Chun Qiao ◽  
Yuan Ouyang ◽  
Sujiang Zhang

Abstract Objective: To investigate the gene mutation and the clinical features of CSF3R, SETBP1 and SRSF2 in chronic neutrophilic leukemia (CNL) and chronic myelomonocytic leukemia (CMML) patients. Method: Sequence analysis of CSF3R, SETBP1 and SRSF2 were performed in 10 CNL and 56 CMML patients whose clinical features were also studied. Result: Among 10 CNL patients, 8(8/10, 80%) patients had CSF3R mutations and 7(7/8, 87.5%) of them were with CSF3R T618I. In 56 cases of patients with CMML, SRSF2 mutations were found in 14(14/56,25%), CSF3R in 4(4/56,7.1%) and SETBP1 in 3(3/56, 5.3%) patients. In CMML, compared to wild-type(wt) SRSF2 patients, SRSF2 mutated patients appeared to be more possible with SETBP1 mutations [1/14(7.1%) vs. 2/42(4.8%), P>0.05], less possible with CSF3R mutation [0/14(0%) vs. 4/42(9.5%), P<0.001]. The clinical characteristics such as age, gender, WHO category, FAB category, karyotype and blood cell counts did not reveal any difference between SRSF2 mutated and wtSRSF2 patients. Either SRSF2 mutated patients or SETBP1 mutated patients both had shorter overall survival (OS) and progression-free survival(PFS) when compared with those with wtSRSF2 (P<0.001 both) and wtSETBP1 (P<0.001 and P=0.02, respectively). No significant difference of OS and PFS between CSF3R mutated and wtCSF3R patients were observed. In multivariate analysis, SRSF2 mutation was an independent negative predictor for OS (HR, 3.307; 95% CI, 1.137 to 9.614; P=0.028) and PFS(HR, 15.431; 95% CI, 3.041 to 78.312; P = 0.001). What's more, SETBP1 mutation was also an independent negative predictor for OS(HR, 9.492; 95% CI, 1.183 to 76.128; P = 0.034). Conclusion: The majority of patients with WHO-defined CNL have oncogenic mutations in CSF3R and the T618I mutation type is a highly sensitive and specific molecular marker of the disease. While mutations of SRSF2 are common in CMML and may be of prognostic significance. As a non-specific molecular marker, SETBP1 was found in CNL, CMML and other blood cancers, which have poor prognosis. Disclosures No relevant conflicts of interest to declare.

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 611-611 ◽  
Author(s):  
Anna Jankowska ◽  
Hideki Makishima ◽  
Ramon V. Tiu ◽  
Hadrian Szpurka ◽  
Yun Huang ◽  
...  

Abstract Abstract 611 Chronic myelomonocytic leukemia (CMML), a myelodysplastic/myeloproliferative overlap neoplasm, is characterized by monocytic proliferation, cytomorphologic dysplasia and frequent progression to acute myelogeneous leukemia (AML). The molecular basis of CMML is poorly defined, although somatic mutations in a number of genes have recently been identified in a proportion of patients. Single nucleotide polymorphisms array (SNP-A) technologies have improved the definition of shared regions of loss of heterozygosity (LOH), including uniparental disomy (UPD) and facilitated discovery of new mutations c-CBL, TET2, and EZH2 which can occur in a homozygous configuration in the areas of UPD. Other mutations such as ASXL1 have been found in heterozygous form. In myeloid malignancies we have also identified mutations in UTX, which like EZH2 and ASXL1, are involved in modification of histone methylation. Based on these findings we hypothesized that defining the mutational spectrum of CMML would help in the molecular characterization of this disease and have diagnostic and prognostic significance. Within this spectrum, we stipulated that various genes involved in epigenetic regulation may be especially affected by mutations in CMML. Here we present results of broad molecular screen in a group of 63 patients with CMML (32 CMML-1, 15 CMML-2 and 16 CMML-derived sAML) which included SNP-A karyotyping and mutational screen for IDH1/2, RAS, TET2, ASXL1, c-CBL, JAK2, UTX and EZH2. First, we aligned all lesions that were detected by SNP-A. In addition to microdeletions involving 4q24 and 11q23.3, we detected recurrent areas of somatic UPD involving chromosomes 1, 4, 7 and 11 and the corresponding homozygous mutations in RAS (UPD1p, N=1), EZH2 (UPD7q N=3), c-CBL (UPD11q, N=4), TET2 (UPD4q, N=6), and UTX genes (UPDXq, N=1). When all patients were sequenced, TET2, ASXL1, c-CBL, IDH1/2, RAS, JAK2, UTX and EZH2 mutations were found in 48%, 24%, 14%, 5%, 11%, 2%, 6% and 8% of patients, respectively. In 78% of patients, >1 mutation was found. Concomitant second and third mutations were found in 34% and 5% of patients, respectively. The most frequently observed combinations included TET2 and ASXL1 (14%) and TET2 and c-CBL (6%). Only 22% of patients had no alterations in analyzed genes. Novel UTX and EZH2 mutations were present either alone or in combination with other mutations. Study of potential functional consequences of the foregoing gene mutations revealed an association of TET2 mutations with consistently low levels of 5-hydroxymethylcytosine (5-hmC), quantitated by dot blot assay, while c-CBL mutations were associated with aberrant phospho-STAT5 staining. Loss of H3K27-me3 in cases with EZH2 mutations but not controls, and an increase in UTX mutant case was identified as measured by ELISA and western blot. When we tested for association of different mutations with pathomorphologic features, specific clinical features were not identified, except for an association of TET2 and c-CBL mutations with more advanced age (p=.0004 and p=.02, respectively), RAS mutation with increased blasts (p=.03) and UTX with dysplastic megakaryocytes (p=.03). Splenomegaly was noted more frequent in c-CBL mutants than any other patient group. No differences in OS and EFS were observed between mutant and wt cases. There is a trend toward better OS in TET2 mutants compared to WT in the good cytogenetic risk group (17 vs 8 mo, p=.07) but worse outcomes in TET2 mutants in the intermediate cytogenetic risk group (OS 2 vs. 16 mo, p=.001; EFS 2 vs. 9 mo, p=.04). As expected, patients who have accumulated more mutations have a trend toward inferior outcomes compared to those with single mutations but better than those who are WT (>1 mutations vs 1 mutation vs WT, 16 vs 18 vs 9 mo, p=.07 in low risk CMML). In summary, our study identified the presence of a wide spectrum of mutations in CMML with various combinations, including the newly discovered mutations in UTX and EZH2 genes. Our results suggest that molecular abnormalities affecting various pathways can lead to a clinically indistinguishable phenotype. It is possible that these mutations are secondary in nature but work in conjunction with a yet unidentified founder defect. The abundance of mutations in factors known or hypothesized to be involved in epigenetic regulation in CMML provide important implications for future research into the development of effective therapies for this disease. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 2864-2864
Author(s):  
Mrinal M Patnaik ◽  
Terra L. Lasho ◽  
Pooja Vijayvargiya ◽  
Christy Finke ◽  
Curtis A. Hanson ◽  
...  

Abstract Background : Gene mutations are common (~90%) in patients with chronic myelomonocytic leukemia (CMML) and involve epigenetic regulators (TET2 ~ 60%, ASXL1 ~40%), spliceosome components (SRSF2 ~40%) and signal pathways (RAS ~30%). Of these, thus far, only ASXL1 mutations have been shown to adversely impact overall survival (OS). In the current study, we used a 27-gene panel assay to identify additional prognostically-relevant mutations in CMML and to also determine if number of mutations carries prognostic relevance. Methods : 175 patients with WHO-defined CMML were included in the study. All patients had bone marrow (BM) biopsies and cytogenetics performed at diagnosis. Targeted capture assays were carried out on BM DNA specimens obtained at diagnosis for the following genes; TET2, DNMT3A, IDH1, IDH2, ASXL1, EZH2, SUZ12, SRSF2, SF3B1, ZRSR2, U2AF1, PTPN11, Tp53, SH2B3, RUNX1, CBL, NRAS, JAK2, CSF3R, FLT3, KIT, CALR, MPL, NPM1, CEBPA, IKZF, and SETBP1. Paired-end indexed libraries were prepared from individual patient DNA using the NEBNext Ultra Library prep protocol on the Agilent Bravo liquid handler. Capture libraries were assembled according to Nimblegen standard library protocol. Base-calling was performed using Illumina's RTA version 1.17.21.3. Genesifter software was utilized to analyze targeted sequence data. Specific variants were deemed as mutations if they were associated with a hematological malignancy (as identified by COSMIC database), or if they were not associated with a dbSNP Results: Among the 175 study patients, 66% were males and median age was 70 years. 146 (83%) patients were subclassified as CMML-1. At a median follow-up of 23 months, 146 (83%) deaths and 25 (14%) leukemic transformations were documented. Median survivals were 24 months for CMML-1 and 16 months for CMML-2 (p=0.38). Mutational frequencies were; TET2 46%, ASXL1 45%, SRSF2 45%, SETBP1 19%, CBL 14%, RUNX1 14%, NRAS 12%, U2AF1 8%, SF3B1 6%, ZRSR2 6%, Tp53 5%, DNMT3A 5%, IDH2 5%, PTPN11 5%, SH2B3 5%, JAK2 4%, NPM1 3%, CSF3R 2%, IDH1 2%, EZH2 1%, SUZ12 1%, KIT 1%, FLT3 1%, CALR 1%. 172 patients (98%) had at least one mutation, 21 (12%) had 2, 24 (14%) had 3, 20 (11%) had 4, 9 (5%) had 5, while one (1%) patient had 6 concurrent mutations. Risk stratification was based on Mayo prognostic model: 25% high, 32% intermediate and 43 % low risk. In univariate analysis, presence of ASXL1 mutations (p=0.01), absence of TET2 mutations (p=0.005) and presence of DNMT3A mutations (p=0.02) were associated with inferior survival; in multivariable analysis, ASXL1 (p=0.01) and TET2 (p=0.03) mutations remained significant. In order to determine prognostic interaction between these two mutations, patients were stratified into four mutational categories: ASXL1wt/TET2wt (n =56), ASXL1mut/TET2wt (n =31), ASXL1mut/TET2mut (n =50) and ASXL1wt/TET2mut (n =38). Survival data in these four groups showed significant difference in favor of ASXL1wt/TET2mut (median survival 38 months; p=0.016), compared to those with ASXL1wt/TET2wt (19 months), ASXL1mut/TET2wt (31 months)and ASXL1mut/TET2mut (16 months); there was no significant difference in survival among the latter three groups (p=0.3) (Figure). The number of mutations per patient did not affect outcome (p=0.3). In multivariable analysis, presence of ASXL1 mutations (P=0.01) and absence of TET2 mutations (p=0.003) remained significant when risk factors used in the Mayo prognostic model (HB <10 gm/dl, AMC >10 x 10(9)/L, platelets <100 x 10(9)/L, circulating IMC) were added to the model; the same was true for ASXL1wt/TET2mut (p=0.036). In a separate multivariable analysis that included the Mayo prognostic model as a single variable along with presence of ASXL1 and absence of TET2 mutations; or absence of ASXL1wt/TET2mut mutational status, the respective hazard ratios were 1.4 (95% CI 1.07-2.1; p=0.012), 1.5 (95% CI 1.07-2.1; p=0.03) and 1.8 (95% CI 1.2-2.7; p=0.001). Leukemia-free survival was worse in ZRSR2 -mutated cases (p=0.03). Conclusions: Almost 100% of patients with CMML express one or more myeloid neoplasm-relevant mutations. The current study suggests a favorable prognostic impact from TET2 mutations, unless accompanied by ASXL1 mutations. Disclosures No relevant conflicts of interest to declare.


Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 4343-4343 ◽  
Author(s):  
Mrinal M Patnaik ◽  
Mohammad Faizan Zahid ◽  
Terra L. Lasho ◽  
Ezequiel Tolosa ◽  
Christy Finke ◽  
...  

Abstract Background : TET2, located on chromosome 4q24, is frequently mutated in the majority of patients with chronic myelomonocytic leukemia (CMML). TET2 has 11 exons, and variations, especially in exon 3 have been described as a part of age related clonal hematopoiesis (Jaiswal NEJM 2015). In CMML, somatic TET2 mutations in the absence of ASXL1 mutations (ASXL1wt/TET2mt) were previously shown to impart a favorable outcome on survival (Patnaik BCJ 2015). In the current larger CMML patient cohort, we describe the number and type of TET2 mutations and examine their phenotypic and prognostic effects. Methods : 261 patients with CMML were included in the study. All patients had bone marrow (BM) biopsies and cytogenetics performed at diagnosis. Targeted capture assays were carried out on BM DNA specimens obtained at diagnosis for the following genes; TET2, DNMT3A, IDH1, IDH2, ASXL1, EZH2, SUZ12, SRSF2, SF3B1, ZRSR2, U2AF1, PTPN11, Tp53, SH2B3, RUNX1, CBL, NRAS, KRAS, JAK2, CSF3R, FLT3, KIT, CALR, MPL, NPM1, CEBPA, IKZF, and SETBP1. TET2 (NM_001127208.2) coverage extended from exons 3-11, with frame shift, non-sense, and missense variations considered pathogenic. Previously annotated single nucleotide polymorphisms (http//www.hapmap.org) were considered non-pathogenic. Results: Among the 261 study patients, 65% were males and median age was 70 years (range, 28-91). 154 (59%), 64 (25%) and 43 (16%) patients were classified as CMML-0, 1 and 2, respectively. At a median follow-up of 23 months, 174 (67%) deaths and 37 (14%) leukemic transformations were documented. Mutational frequencies ≥4% were encountered in; ASXL1 45%, TET2 42%, SRSF2 40%, NRAS 14%, SETBP1 13%, CBL 10%, JAK2 7%, RUNX1 6%, DNMT3A 6%, U2AF1 6%, SF3B1 5%, ZRSR2 4%, Tp53 4% and IDH2 4%. i) TET2 mutations type, number and phenotypic correlates: TET2 mutations were seen in 109 (42%) patients; these included frameshift 33 (30%), nonsense 29 (27%) and missense 11 (10%) variants whereas 36 (33%) had more than one type of mutation. Overall, 57 (52%) patients had more than 1 TET2 mutations: 52 (48%) patients had 1, 46 (42%) 2 and 11 (10%) ≥3 TET2 mutations. Among all 109 TET2 mutated patients, 65% were male, and median age was 71 years with no significant difference in age and gender distribution between mutated and un-mutated cases, or type of TET2 mutations; however, older patients were more likely to carry multiple TET2 mutations (p=0.01). Compared to their un-mutated counterparts, TET2 mutated cases were less likely to have a low hemoglobin (p<0.001), circulating immature myeloid cells (IMC) (p=0.001), peripheral blood (PB) (p=0.009) and BM blasts (p=0.009), and have high-risk stratification per Mayo Molecular Model (p<0.001); these differences were not affected by the type or number of TET2 mutations. TET2 mutated cases were more likely to have a higher frequency of SRSF2 (p=0.004) and lower frequency of ASXL1 (p=0.03), Tp53 (p=0.04) and IDH1/2 mutations (p<0.001); these associations were also not affected by the type or number of TET2 mutations. ii) Impact on survival: Median survival for the entire cohort (n=261) was 24 months. In univariate analysis, survival was superior in TET2 mutated (median 33 months) versus wild-type (median 21 months) patients [p=0.03; HR 1.3 95% CI 1.12-1.86] (figure 1A). This survival difference remained significant after adjustment for age (p=0.04), leukocyte count (p=0.017), absolute monocyte count (p=0.02), absolute lymphocyte count (p=0.02), platelet count (p=0.015), circulating IMC (p=0.03), DNMT3A (p=0.02) and ASXL1 (p=0.045) mutations; however, significance was lost after adjustment for abnormal karyotype (p=0.32) and the Mayo Molecular Model (p=0.0003). These observations were not affected by the type or number of TET2 mutations. Finally, our previous observation regarding the survival advantage of ASXL1wt/TET2mt versus other genotypes was most apparent for patients with multiple TET2 mutations (p=0.02) (figure 1B). Conclusions: TET2 mutations are common in CMML and constitute approximately equal proportions of frameshift and non-sense mutations, while missense mutations are less frequent. Majority of TET2 mutated CMML cases harbor more than one mutant variant. Regardless, the relevance of type and number of TET2 mutations in CMML was limited to an association between older age and number of mutations and the latter with possibly improved survival in the absence of clonal ASXL1 mutations. Disclosures No relevant conflicts of interest to declare.


2017 ◽  
Vol 87 (3) ◽  
Author(s):  
Cuneyt Tetikkurt ◽  
Halil Yanardag ◽  
Metin Pehlivan ◽  
Muammer Bilir

Sarcoidosis is a systemic disease characterized by noncasefied granulomas in various organs. Incidence of splenic disease is variable and is reported to occur in 6.7 to 77 percent of the patients. Firm data establishing the clinical features and the association of splenic involvement with prognosis in sarcoidosis is scant. The aim of our study was to investigate the clinical features and the consequence of splenic involvement on the prognostic outcome of sarcoidosis patients. We evaluated the clinical and laboratory findings in 82 sarcoidosis patients. Forty-two patients with splenic involvement were compared to 48 sarcoidosis patients without splenic disease in regard to laboratory findings, endobronchial disease, extrapulmonary organ involvement, and prognosis. Lung biopsy sample was considered positive if it demonstrated noncaseating granulomas with negative fungal and mycobacterial cultures. Splenic sarcoidosis was identified by ultrasound or computed tomography and was designated as limited, diffuse or without splenic involvement. Extrapulmonary organ sarcoidosis was classified as extensive and limited. Endobronchial disease was categorized as limited or diffuse involvement. The most commonly comprised organ was lung in 95% of the cases followed by lymph nodes, skin, eye, spleen and liver in the order of frequency. Splenic disease was diffuse in 22 patients. Of these patients, 14 had extensive extrapulmonary organ involvement while 16 had diffuse endobronchial disease. There was no significant difference between the three groups for FEV1, FVC, TLC, DLCO/VA, serum and 24h urinary calcium levels. Serum ACE was higher in patients with diffuse splenic involvement (p<0.001). Incidence of persistent chronic disease was significantly higher (p<0.001) in patients with diffuse splenic sarcoidosis. Extensive extrapulmonary organ involvement and diffuse endobronchial disease were more common (p<0.001) in this group. Extensive extrapulmonary organ involvement and diffuse endobronchial disease were more frequent in patients with diffuse splenic sarcoidosis. Patients with diffuse splenic granulomas had a worse prognosis than the patients without splenic involvement or patients with limited splenic disease. Diffuse splenic involvement emerges to be a significant risk factor for persistent chronic sarcoidosis. Extensive granuloma burden in an organ may be the decisive clinical marker for the prognostic outcome of sarcoidosis patients. 


Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 2452-2452
Author(s):  
Gudrun Gohring ◽  
Kyra Michalova ◽  
Berna Beverloo ◽  
David Betts ◽  
Jochen Harbott ◽  
...  

Abstract Disclosure: No relevant conflicts of interest to declare. To study the clinical significance of recurrent chromosome aberrations in childhood MDS, cytogenetic data of 394 consecutive children with refractory cytopenia (RC) (N=215), RAEB (N=141) and RAEB-T (N=38) analyzed in the regional cytogenetic reference centers and registered in the prospective study EWOG-MDS 98 between 1998 and 2005 were evaluated. At diagnosis, a karyotype could be defined in 279/394 patients (pts) (71%). No karyotype was obtained in 16% of pts with RC compared to 8% pts with RAEB and RAEB-t (p&lt;0.001). Clonal chromosome aberrations were more common in pts with advanced MDS (RAEB and RAEB-T, 61%) compared to RC (29%), and in pts with secondary (69%) compared to primary MDS (36%) (p&lt;0.001). Monosomy 7 was the most frequent aberration occurring with similar frequency in RC (47% of abnormal karyotypes) compared to advanced MDS (49%) and in primary (53%) compared to secondary (41%) MDS. In addition, aberrations typical for de novo AML such as aberrations involving 11q23 or 3q, t(6;9) and del(9q) were noted in morphologically and clinically unequivocal MDS cases. Recurrent aberrations of adult MDS like isolated del(5q), del(20q) and -Y were very uncommon indicating a different pathogenesis of these cases. In pts with advanced MDS, there was no significant difference in overall survival (OS) of pts with normal karyotype (44% ± 18) compared to pts with monosomy 7 (58% ± 19) and patients with other karyotypes (61% ± 22). However, pts with advanced MDS and a complex karyotype (defined by ≥ 3 chromosome aberrations, presence of structural aberrations and excluding clonal evolution of monosomy 7) had a shorter OS (16% ±15, p&lt;0.01). OS and event-free survival after hematopoietic stem cell transplantation (HSCT) in pts with complex karyotypes was inferior compared to that of pts with other cytogenetic aberrations (p=0.012 and 0.039, respectively). Within the group of pts with secondary MDS, complex karyotypes were found in MDS evolving from inherited bone marrow failure disorders or after radio-/ chemotherapy, but absent in familial MDS and cases evolving from acquired aplastic anemia. As shown in a multivariate Cox analysis, advanced MDS, secondary MDS, the presence of a complex karyotype and HSCT were identified as independent prognostic factors for OS. Thus, this study demonstrates the prognostic significance of cytogenetic findings in advanced childhood MDS independent of HSCT.


Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 3895-3895
Author(s):  
Juliana Popa ◽  
Susanne Schnittger ◽  
Philipp Erben ◽  
Tamara Weiss ◽  
Ayalew Tefferi ◽  
...  

Abstract Abstract 3895 Poster Board III-831 A genome-wide single nucleotide polymorphism (SNP) screen led to the identification of 11q aUPD in patients diagnosed with various subtypes of myeloproliferative neoplasms (MPN), e.g. chronic myelomonocytic leukemia (CMML), atypical chronic myeloid leukemia (aCML) and myelofibrosis (MF) (Grand et al., Blood 2009;113:6182). Further molecular analyses revealed acquired activating point and length mutations in CBL exons 8 and 9 in 10% of CMML, 8% of aCML and 6% of MF cases. Most variants were missense substitutions in the RING or linker domains that abrogated CBL ubiquitin ligase activity and conferred a proliferative advantage to 32D cells overexpressing FLT3. In this study, 160 patients with BCR-ABL and JAK2 V617F negative MPNs were screened for CBL mutations by PCR and direct sequencing. Eighteen known (Y371H, L380P [2x], C381R, C381Y [2x], C384Y, C396Y, H398P, H398Q, W408C, P417H, F418L, R420Q [5x]) and four new (F378L, G397V, I423N, V430M) missense mutations affecting fourteen residues were identified in 20 patients. Two patients harbored two different mutations. The clinical phenotype could be characterized more precisely in 17 patients. Median age was 68 years (range 59–85) with a slight female predominance (f, n=10; m, n=7). Striking hematological features were leukocytosis (14/17; 82%; median 29,000/μl, range 4,500-141,000) with continuously left-shifted granulopoiesis (blasts, promyelocytes, myelocytes, metamyelocytes) in 85% and elevated monocytes (median 2,500/μl, range 630-10,656) >1,000/μL in 88% (15/17) of patients. Eosinophilia (>1,500/μL) was rare (3/17, 18%). Anemia (normal values: f, Hb <12g/dL; m, Hb <14g/dL) was present in all 17 patients (f, median 10g/dL, range 8.7-11.8; m, median 11.2g/dL, range 8.6-12.9). Platelets did not exceed 300,000/μL in any patient while 11/17 (65%) patients presented with thrombocytopenia (median 125,000/μL, range 18,000-271,000). Splenomegaly was present in 11/17 patients (65%) and LDH was elevated (median 304U/L, range 189-729) in 9/17 patients (52%). Bone marrow histology and immunohistochemistry were available from 12 patients. Relevant features were hypercellularity, marked granulopoiesis and microlobulated megakaryocytes without clusters in 11/12 patients (92%), respectively. Increased fibres were seen in 8/12 (67%) patients of whom one showed severe fibrosis. Clinical follow-up was available from 17 patients. Thirteen patients (76%) have died because of progression to secondary acute myeloid leukemia/blast phase (n=7), cytopenia-related complications (n=2) or for unknown reasons (n=4) after a median of 23 months (range 3-60) following diagnosis. In conclusion, point mutations of CBL exons 8 and 9 are present in approximately 6-12% of BCR-ABL and JAK2 V617F negative MPNs. They are associated with a distinct clinical and hematological phenotype presenting with myeloproliferative features allowing diagnosis of a proliferative subtype of CMML rather than aCML or MF in the majority of cases. Patients with left-shifted leukocytosis, monocytosis, anemia and lack of thrombocytosis who are negative for BCR-ABL and point or length mutations of JAK2 should be routinely screened for CBL mutations. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 1402-1402
Author(s):  
Hideki Makishima ◽  
Anna M Jankowska ◽  
Valeria Visconte ◽  
Ramon V. Tiu ◽  
Kathryn M Guinta ◽  
...  

Abstract Abstract 1402 Chronic myelomonocytic leukemia (CMML) is characterized by monocytic proliferation, cytomorphologic dysplasia and frequent progression to acute myelogeneous leukemia (AML). The molecular basis of CMML is poorly defined, although somatic mutations in a number of genes have recently been identified in a proportion of patients (epigenetic regulatory genes, spliceosomal genes, apoptosis genes, growth signal transducers and others). We performed a comprehensive analysis of molecular lesions, including somatic mutations detected by sequencing and chromosomal abnormalities investigated by metaphase and SNP-array karyotyping. We have selected a cohort of 72 patients (36 CMML1, 16 CMML2 and 20 sAML evolved from CMML). Our mutational screen performed in stages (as new mutations were discovered by our and other groups) and currently reveals mutations in UTX in 8%, DNMT3A in 9%, CBL in 14%, IDH1/2 in 4%, KRAS in 2.7%, NRAS in 4.1%, JAK2 in 1%, TET2 in 48%, ASXL1 in 43%, EZH2 in 5.5%, RUNX1 37%. Based on the discovery of various spliceosomal mutations in myeloid malignancies, novel mutations were also found in CMML, in U2AF1 in 12%, SF3B1 in 14%, SFRS19 in 6 % of cases tested. Chromosomal defects were detected in 60% of patients. In particular, a high frequency of somatic uniparental disomy (sUPD) were identified 71% of patients with abnormal cytogenetics, including UPD1p (N=3), UPD7q (N=8), UPD4q (N=6), UPD2p (N=2), UPD17q (N=2), UPD11q (N=5), UPDX (N=1), UPD21q (N=2). Some of the detected mutations were homozygous through their association with sUPD as for example for 3 EZH2, 1 UTX, 6 TET2, 2 DNMT3A, 5 CBL, 1 NRAS, 1 U2AF1 mutations. Furthermore, UPD17p implies that a P53 mutation is also present in this case as previously LOH17p was shown to be invariably associated with P53 mutations. Similarly, 2 cases of UPD17q imply that homozygous mutation of SRSF2, which is one of the Serine/arginine-rich splicing factor, may be present in this location and the mutation analysis is ongoing. In over 90% of >1 mutation was found but many patients harbored multiple mutations with frequent combinations of TET2/CBL or TET2/ASXL1 as well as RUNX1 and U2AF1 serving as examples. There was an accumulation of mutations from sAML, CMML2 and CMML1 suggesting stepwise accumulation of lesions. In serial studies, some of the mutations were present at the inception (e.g., TET2, ASXL1 and DNMT3A) in some cases originally heterozygous mutations were also while other can occur in the course of disease (e.g. CBL). RAS and DNMT3A mutations were associated with a higher blasts count. In sum, combined analysis of molecular lesions in CMML reveals that similar phenotype may be a result of diverse mutations associated with seemingly unrelated pathways and that clinical phenotype may be a result of a combination of mutations which accumulate as the disease progresses. Survival analyses will require large cohorts to account for various confounding factors including the presence of multiple chromosomal abnormalities and mutations in one patient, however currently EZH2, DNMT3 and CBL mutations appear to convey less favorable prognosis. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 2329-2329
Author(s):  
Yukiko Komeno ◽  
Ming Yan ◽  
Shinobu Matsuura ◽  
Miao-Chia Lo ◽  
James R. Downing ◽  
...  

Abstract Abstract 2329 Previously reported “RUNX1-IRES-GFP knock-in mice” (Blood 2004;103:2522) (KI mice) were generated by replacing exon 4 of runx1 gene with cDNA of Runx1b/c from exon 4 to exon 8 followed by IRES-GFP, aiming to evaluate Runx1 expression in specific lineages and developmental stages during adult hematopoiesis. They are phenotypically normal, fertile, and blood indices are normal. GFP intensity correlates with Runx1 expression level, and shows lineage-specific changes during maturation in myeloid, erythroid, and lymphoid cells. However, the behavior in the hematopoietic stem cells (HSCs) had not been carefully examined. Interestingly, we discovered that this knock-in strategy eliminated Runx1a expression. Since Runx1a expression is relatively higher in HSCs than in differentiated cells, we analyzed HSCs in these mice to evaluate its roles in stable and stress hematopoiesis. We found that LSK fraction in bone marrow (BM) was significantly decreased in KI mice compared to wild type (WT) mice (0.043% vs 0.085%, p = 0.001). Among subpopulations in LSK, short-term HSC and multipotent progenitor fractions were significantly decreased (0.024% vs 0.046%, p = 0.003, 0.0021% vs 0.0026%, p = 0.001, respectively). SLAM marker staining using CD150 and CD48 showed similar results. Competitive repopulation assay showed less functional HSCs in KI mice. However, there was no significant difference in recovery of cell counts after single-dose 5-FU intraperitoneal injection (150 mg/kg body weight) or sublethal irradiation (5 Gy), or survival after weekly 5-FU injection. After G-CSF subcutaneous injection (125 μg/kg body weight, twice daily for 5 days), mobilized WBC or neutrophil in PB showed no difference. However, LSK and long-term HSC in PB were significantly less in KI mice (0.078% vs 0.135%, p = 0.010, 0.043% vs 0.092%, p = 0.029, respectively) while those in BM did not show significant difference (increased to 0.295% and 0.346% in KI and WT mice, respectively). In conclusion, Runx1a plays some non-redundant roles in stable hematopoiesis, while it is dispensable for tested stress hematopoiesis. RUNX1-GFP KI mice are a versatile tool to evaluate roles of Runx1a in normal hematopoiesis and leukemogenesis when combined with other genetic modifications. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 2842-2842
Author(s):  
Zadie Davis ◽  
Anton Parker ◽  
Daniel Catovsky ◽  
David Oscier

Abstract Abstract 2842 IGHV gene mutational load and use of specific IGHV genes and stereotypes have all been reported to have prognostic significance in CLL. In the UK CLL4 trial there were significant differences in response rate and progression free survival regardless of whether a 97% or 98% cut off was used, and the percentage of mutations which correlates best with clinical outcome remains controversial. We performed IGHV gene sequencing on 1071 patients with CLL or ‘clinical’ MBL (n= 153) in whom biomarkers, time to first treatment (TTFT) and overall survival (OS) were available. Four hundred and ninety six cases were entered into the UK CLL4 trial and 575 presented or were referred to the Royal Bournemouth Hospital. TTFT and OS were determined for cases with <96% identity and for each mutational point from 96% – 100% identity separately, excluding cases utilising IGHV3-21 assigned to stereotype subset 2. There was a significant difference in median TTFT and median OS between those with 97% identity (TTFT-20.9 and OS-99.3 months) and <97% identity (TTFT-118 and OS-191 months; p<0.001 and p<0.001), but not between cases with 97% and >97% identity (TTFT -13.1 months p=0.052 and OS-84.5 months p=0.177). When TTFT was determined for patients with early stage disease only (stage A CLL or CLL-like MBL, n=571), those with 97% identity, determined using either leader sequence or BIOMED 2 primers, had a significantly longer median TTFT than those with >97% identity (92.0 and 36.4 months respectively; p=0.012) and significantly shorter than those cases with <97% identity (273.1 months; p=0.012). If only stage A cases were analysed, those with 97% identity had a significantly longer median TTFT than those with >97% identity (TTFT; 68 vs. 26 months p=0.034). However, when compared to cases with <97% identity, there was a trend towards a shorter TTFT but significance was not reached (68 vs. 128 months p=0.060). A series of Cox Regression analyses were conducted to see if the prognostic value of the 98% cut off in MBL/stage A cases could be improved. In univariate analyses a model which incorporated <97%, 97%, >97% identity and stereotype subset 2 was the best discriminator of TTFT (p=0.0011) (Figure 1).Figure 1.Four subgroups of MBL/stage A CLL with differing TTFT based on stereotype subset 2 and relationship to 97% germline identityFigure 1. Four subgroups of MBL/stage A CLL with differing TTFT based on stereotype subset 2 and relationship to 97% germline identity Multivariate analysis, selected 97% and >97% identity as independent predictors of shorter TTFT (HR 2.5; 95% CI 1.3–4.9; p=0.007 and HR 4.2; 95% CI 2.9–6.1; p<0.001 respectively) in a model including <97%, 97%, >97% identity to germline, age at diagnosis, gender, expression of ZAP70, expression of CD38, del11q, del17p, stereotypy and stereotype subset 2 (Table 1). Further analyses were performed to investigate whether the differences in TTFT between cases with <97%, 97% or >97% identity could be explained by differences in IGHV gene usage. Sixty-one percent of cases with 97% identity to germline utilised only five genes; IGHV3-21, IGHV3-23, IGHV3-48, IGHV3-53 and IGHV1-18 and these genes were significantly over-represented in cases with 97% compared to either, cases with <97% (p>0.001) or >97% (p>0.001). When subset 2 cases were excluded, there was no difference in TTFT between cases using the above 5 genes and all other IGHV genes at this identity (p=0.288). In contrast to previously published data we found no difference in TTFT between mutated IGHV3-23 cases and other mutated cases (using a 98% cut-off), but IGHV3-23 cases with 97% identity had a shorter TTFT than cases with <97% identity (p<0.001). In conclusion the clinical course of cases with 97% identity, especially if diagnosed early in their disease, appears distinct from other cases defined as having mutated IGHV genes using the conventional 98% cut off. This is not accounted for by differences in IGHV gene usage, the incidence of stereotypy or other biomarkers and may reflect differences in response to BCR stimulation between cases with 97% and <97% identity.Table.Multivariate analysis for TTFT in MBL/stage A CLLOutcomeCovariateHazard Ratio (HR)95% CI for HRSignificance (p)TTFT97% identity2.51.3–4.90.007>97% identity4.22.9–6.1<0.001Subset 23.71.8–7.4<0.001Del11q1.71.1–2.70.014CD381.51.0–2.00.028Age at diagnosis0.980.96–0.99<0.001 Only covariates selected as significant are listed above. Disclosures: No relevant conflicts of interest to declare.


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