Leukemia Initiating Cells: New Markers for Minimal Residual Disease Monitoring in B-Precursor Acute Lymphoblastic Leukemia

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 2528-2528
Author(s):  
Yuan Kong ◽  
Yan-rong Liu ◽  
Le Hao ◽  
Ya-zhe Wang ◽  
Kai-yan Liu ◽  
...  

Abstract Abstract 2528 Background: Minimal residual disease(MRD) is currently the most powerful prognostic indicator in childhood ALL as well as in adult ALL. Using neonatal NOD/SCID/IL2rγnull xenotransplantation model, we previously demonstrated that CD34+CD38+CD19+ cells as well as CD34+CD38−CD19+ cells have the capacities to initiate B-ALL in vivo and to self-renew, that is, CD34+CD19+ cells are leukemia initiating cells(LICs) in human B-precursor ALL (B-ALL)(Kong Y et al. Leukemia 2008; 22: 1207–1213). Nevertheless, immunophenotypic differences between B-ALL initiating cells and normal progenitor B cells have not been clearly clarified. Especially, whether the LICs identified in xenotransplantation assay are clinically useful for routine MRD monitoring in B-ALL patients is largely unknown. Objective: To compare phenotypic characteristics of LICs in B-ALL patients to that of normal progenitor B cells in healthy donors. To evaluate clinical significances of LICs as novel MRD markers in predicting relapses in human B-precursor ALL. Materials and methods: To identify new markers for MRD detection in B-ALL, we compared phenotypic characterization of LICs from 40 patients with newly diagnosed B-ALL and 40 patients with relapsed B-ALL to that of normal progenitor B cells from 40 healthy donors by seven-color flow cytometry (FCM). Comparative analysis was performed at mean fluorescence intensity (MFI) of CD38, CD45, CD58 and CD123 on CD34+CD19+ cells among the above three groups. Subsequently, the most promising markers were examined in detail for their usefulness as MRD markers by seven-color FCM at different time points in 823 patients (including pediatric and adult patients) with B-ALL from January 2010 to June 2011 at Peking University Institute of Hematology. A total of 1,050,000 events were routinely collected. More than 0.001% of LICs with aberrant highly expression of CD123 and/or CD58 in bone marrow samples detected by seven-color FCM were defined as FCM positive (FCM+). FCM positivity at any time was defined as MRD positive (FCM MRD+), all others cases were defined as MRD negative (FCM MRD−). Real-time quantitative polymerase chain reaction (RQ-PCR) was applied concurrently to evaluate MRD in Philadelphia chromosome positive ALL (Ph+ ALL) patients. The value of BCR/ABL equal to 0 was defined as RQ-PCR negative (RQ-PCR-). The results of MRD studies by the two methods were recorded independently. Results: MFI of CD58(3.46±1.85 vs.3.82±1.83 vs.1.35±0.77, p<0.001) and CD123(6.37±3.47 vs.7.56±3.90 vs. 3.66±1.94, p<0.001) was significantly higher on LICs from newly diagnosed B-ALL and relapsed B-ALL than that of their normal counterparts. Meanwhile, MFI of CD38(8.09±6.36 vs.11.23±8.59 vs. 37.89±7.91, p<0.05) and CD45(7.42±5.14 vs.9.91±7.72 vs.13.50±8.20, p<0.05) was significantly lower on LICs than that of their normal counterparts. Further ANOVA analysis by LSD method demonstrated MFI of CD38, CD45, CD58 and CD123 on LICs differed significantly from that of normal progenitor B cells, whereas the phenotypic differences on LICs from newly diagnosed B-ALL or relapsed B-ALL showed no statistically significance. In the sequential MRD follow up, 185 samples from110 cases of B-ALL were detected as FCM MRD+. Among them, LICs from 56 cases(51%) with aberrant highly CD58 expression, 106 cases(96%) with aberrant highly CD123 expression and 40 cases(36%) with simultaneously aberrant highly expressions of CD58 and CD123. Twenty-two cases relapsed during MRD monitoring, of them 19 cases were detected as FCM MRD+ at a median time of 57 days (13–90days) before their recurrence. The left 3 relapsed cases did not monitor MRD status for about 3 months as we expected. MRD analysis was performed concurrently by both RQ-PCR and FCM in 85 follow-up bone marrow samples from 23 Ph+ ALL patients. A good correlation was found between RQ-PCR and FCM (Spearman r=0.883, p< 0.001). Conclusions: Mean fluorescence intensity of CD38, CD45, CD58 and CD123 antigens distinguished B-ALL initiating cells from their normal counterparts, CD34+CD19+ normal progenitor B cells. The B-ALL initiating cells with aberrant highly expression of CD123 and/or CD58 detected by seven-color FCM may serve as promising markers for MRD monitoring in B-ALL. Disclosures: No relevant conflicts of interest to declare.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. 8010-8010
Author(s):  
Noemi Puig ◽  
Bruno Paiva ◽  
Teresa Contreras ◽  
M. Teresa Cedena ◽  
Laura Rosiñol ◽  
...  

8010 Background: Analysis of minimal residual disease (MRD) in the bone marrow (BM) of patients with multiple myeloma (MM) is accepted by the IMWG to evaluate treatment efficacy and is a well-established prognostic factor. However, there is an unmet need to explore the clinical value of MRD in peripheral blood (PB). Methods: Newly diagnosed MM patients enrolled in the GEM2012MENOS65 trial received six induction (Ind) cycles of bortezomib, lenalidomide, and dexamethasone (VRD) followed by autologous stem cell transplantation (ASCT) and 2 further cycles of consolidation (Cons) with VRD. MRD was analyzed in BM using Next Generation Flow (NGF) and in serum by Mass Spectrometry (MS) using IgG/A/M, κ, λ, free κ and free λ specific beads, both after Ind, at day 100 after ASCT, and after Cons. Sequential samples from the first 184 patients were analyzed. Results: Results of both methods were in agreement (NGF+/MS+ and NGF-/MS-) in 83% of cases post-Ind (152/184), 80% post-ASCT (139/174) and 76% post-Cons (128/169). Stratifying by the log range of MRD by NGF, discordances (NGF+/MS- and NGF-/MS+) seemed to increase at the lower MRD ranges, being 22%, 21% and 19% from ≥10−5 to <10−4 and 21%, 21%, 23% at ≥x10−6(post-Ind, ASCT and Cons, respectively). Analysis of discordances showed that they could be partly explained by the higher percentages of cases found to be positive by MS as compared by NGF at part of the time-points analyzed and at each log range of MRD. From ≥10−5 to <10−4, MRD was detected by NGF in 36%, 28%, 20% of cases post-Ind, ASCT and Cons, respectively vs MS in 37%, 29%, 21% of them; at ≥x10−6, NGF was positive in 11%, 14%, 19% of cases vs MS in 23%, 19% and 16% of them. Considering NGF as a reference, the negative predictive value (NPV) of MS per MRD range (≥10−5 to <10−4 and ≥x10−6, respectively) was: post-Ind: 83% (p<0,0001), 94% (p=0,034); post-ASCT 86% (p<0,0001), 90% (p=0,022); post-Cons 89% (p<0,0001), 85% (p=0,0469). Despite these discordances, the prognostic value of each technique in terms of undetectable MRD and progression-free survival (PFS) was consistent at all time-points (Table) and further, discordant cases (NGF+/MS- and NGF-/MS+) did not display a significantly different PFS as compared to NGF-/MS- cases. Conclusions: The results of MRD assessed by NGF in BM and by MS in PB show a significant concordance and are associated with a similar prognostic value analyzed in terms of PFS. Given its high NPV, MRD in peripheral blood by MS provides a gateway for BM aspiration/biopsy and MRD assessment by NGF.[Table: see text]


Blood ◽  
1996 ◽  
Vol 87 (4) ◽  
pp. 1556-1560 ◽  
Author(s):  
S Wheaton ◽  
MS Tallman ◽  
D Hakimian ◽  
L Peterson

Minimal residual disease (MRD) can be detected in bone marrow core biopsies of patients with hairy cell leukemia (HCL) after treatment with 2-chlorodeoxyadenosine (2-CdA) using immunohistochemical (IHC) techniques. The purpose of this study was to determine whether the presence of MRD predicts bone marrow relapse. We studied paraffin- embedded bone marrow core biopsies from 39 patients with HCL in complete remission (CR) 3 months after a single cycle of 2-CdA. Biopsies performed 3 months posttherapy and annually thereafter were examined by routine hematoxylin and eosin (H&E) staining and IHC using the monoclonal antibodies (MoAbs) anti-CD45RO, anti-CD20, and DBA.44. At 3 months after therapy, 5 of 39 (13%) patients had MRD detectable by IHC that was not evident by routine H&E staining. Two of the five patients (40%) with MRD at 3 months have relapsed, whereas only 2 of 27 (7%) patients with no MRD and at least 1 year of follow up relapsed (P = .11). Over the 3-year follow-up period, two additional patients developed MRD. Overall, three of six (50%) patients with MRD detected at any time after therapy have relapsed, whereas only 1 of 25 (4%) patients without MRD has relapsed (P = .016). These data suggest that the presence of MRD after treatment with 2-CdA may predict relapse.


Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 4672-4672
Author(s):  
Dana Dvorakova ◽  
Zdenek Racil ◽  
Ivo Palasek ◽  
Marketa Protivankova ◽  
Ivana Jeziskova ◽  
...  

Abstract Abstract 4672 Background Mutations within NPM1 gene occurs in about 60% of adult cytogenetic normal AML (CN-AML) and represent the single most frequent molecular aberration in this subgroups of patients. These mutations usually occur at exon 12 and induce most frequently a net insertion of four base pairs. Aims To examine the applicability and sensitivity of DNA-based real-time quantitative polymerase chain reaction (RQ-PCR) with mutation-specific reverse primers and common minor groove binding (MGB) probe and to evaluate whether minimal residual disease levels are of prognostic relevance in CN-AML patients with NPM1 mutations. Methods Patients were treated within different AML trials and follow-up samples of peripheral blood or bone marrow were referred to perform an RQ-PCR. Samples were analysed at diagnosis, during, and after therapy. The NPM1 mutations were A (17 pts), B (1 pt), D (2 pts) and 7 patients with individual rare types. For all cases, levels of minimal residual disease were determined by DNA-based RQ-PCR with mutation-specific reverse primer, one common forward primer and one common MGB probe. The NPM1 mutation value was normalized on the number of albumin gene copies and expressed as the number of NPM1 mutations every 106 genomic equivalents. This assay is highly specific as no wildtype NPM1 could be detected. Maximal reproducible sensitivity was 10 plasmide molecules per reaction. Results A total of 950 samples of bone marrow and/or peripheral blood from 27 patients have been analyzed. Twenty of 27 patients (74%) achieved molecular remission (MR), twenty-six of 27 patients (96%) achieved hematological remission (HR). 6 of 27 (22%) patients achieved HR without MR and one patient failed therapy. 8 of 20 patients (40%) with MR after treatment relapsed at molecular level and except one in all these patients hematological relaps occured (one patient is still in HR with bone marrow blast present, but < 5%). Considering relapsed patients, time from molecular to hematological relapse was 1 to 5 months (median: 3 months). Considering all 14 patients with HR without MR (6 pts) or with molecular relapse (8 pts), in 11 of them hematological relaps occured (79%) and molecular positivity anticipating hematological relaps with median of 3,5 month (1-7 months). 3 of these 14 patients are still in HR. Conclusions Mutations within NPM1 gene are a sensitive marker for monitoring minimal residual disease in CN-AML patients. RQ-PCR using a MGB probe is an efficient approach to long-term follow-up of residual leukemia cells and frequent quantitative monitoring is useful for reliably predicting hematological relapse. Achievement of negativity appears to predict favorable clinical outcome. This work was partially supported by research grant No. MSM0021622430 Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 4908-4908 ◽  
Author(s):  
Giordana Pastori ◽  
Fabio Guolo ◽  
Daniela Guardo ◽  
Paola Minetto ◽  
Marino Clavio ◽  
...  

Abstract BACKGROUND AND AIMS The prognosis of Philadelphia positive (Ph+) acute lymphoblastic leukemia (ALL) patients has improved since the introduction of tyrosine kinase inhibitors (TKI). The inclusion of TKIs in standard ALL protocols allows a great increase in complete molecular responses, but at the price of non negligible toxicities and high rates of toxic deaths. On the other and TKI monotherapy as induction treatment allows to rapidly achieve complete hematologic remission (CR) but only a minority of patients achieve a complete molecular response with high risk of relapse. On the other hand, In the last years we tested a combination of Fludarabine, Cytarabine, Daunoxome (FLAD) with or without TKIs (mainly Dasatinib) as salvage regimen in relapsed-refractory ALL, with acceptable toxicity and good efficacy. We decided to apply the same schedule in newly diagnosed Ph+ ALL as consolidation treatment after a two months TKI (Dasatinib) monotherapy induction on a minimal residual disease condition. MATERIALS AND METHODS FLAD regimen consisted with a three-days administration of Fludarabine 30 mg/sqm followed four hours later by Cytarabine 2000 mg/sqm and Daunoxome 100 mg/sqm. TKI were suspended during chemotherapy administration and were re-administrated starting from day 5. G-CSF was given to all patients from day 4 to complete hematological recovery. FLAD was administrated for up to two cycles; all patients with available donor proceeded to allogeneic bone marrow transplantation (allo-BMT) after FLAD. Minimal residual disease (MRD) was evaluated in all patients after each FLAD either by RQ-PCR for VDJ rearrangements, multicolor flow cytometry (MFC) and RQ-PCR for BCR/Abl. Ten Ph+ ALL have been treated with FLAD + TKIs from January 2008 to December 2014: six patients received FLAD as salvage regimen, two of them in post allo-BMT setting, whereas four patients were treated frontline, after hematological CR was obtained with Dasatinib + steroids induction. All frontline patients proceeded to allo-BMT after two FLAD. Median age for frontline patients was 50 years (range 29-58), median follow-up was 20 months. RESULTS As salvage regimen, 5/6 patients achieved hematological CR after FLAD, with three patients achieving also MFC MRD negativity and clearance of VDJ and BCR/Abl transcript. All patients who did not receive subsequent BMT relapsed, whereas of the two transplanted patients one is still in CR after a follow-up of 38 months. In the frontline setting, all patients received 70 days induction of Dasatinib + Steroids and achieved CR with complete hematological recovery. BCR/Abl transcript could be detected in all patients on BM samples on day 33 and on day 70 (Fig. 1), two patientshad MFC MRD positivity both on day 33 and on day 70, whereas two patients achieved MFC MRD negativity on day 33. FLAD was very well tolerated, with negligible non hematological toxicity, with a median duration of ANC <500 and PLT <20000 of 7 and 9 days, respectively, slightly higher in the second course. Median time between the beginning of first and second course was 35 days, whereas median time from second course to allo-BM was 44 days. Two patients achieved BCR/Abl negativity after first FLAD. All patients achieved molecular complete response after the second course (Fig. 1). No patient experienced relapse, whereas one patient died in CR on day +289 after allo-BMT due to myocardial viral infection. CONCLUSIONS FLAD has a very good efficacy in adult Ph+ ALL, with an acceptable toxicity profile. Deep responses have been observed in relapsed patients, and all newly diagnosed patients who received FLAD as consolidation regimen had achieved molecular CR before allo-BMT. Achieving complete hematological response with Dasatinib + steroids allowed us to safely administer two FLAD courses. Figure 1. BCR/abl on bone marrow samples at different timepoints for each of the four patients receiving FLAD as consolidation therapy Figure 1. BCR/abl on bone marrow samples at different timepoints for each of the four patients receiving FLAD as consolidation therapy Disclosures Off Label Use: Use of liposomal daunorubicin in the treatment of ALL.


Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 4956-4956
Author(s):  
Weiqin Yao ◽  
Zhu Mingqing ◽  
Yao Feirong ◽  
Lingzhi Yan ◽  
Song Jin ◽  
...  

Abstract Objective: In the last decade the outcome in multiple myeloma in CHINA has greatly improved due to the new, effective therapies including PIs and Imids. But responses to treatment and survival remains heterogeneous because of patient characteristic, disease biology and mechanisms of drug resistance. More and more studies have established the link between depth of response and improved PFS and OS. multiparameter-flow cytometry (MFC) is a main method to detect minimal residual disease(MRD) in myeloma. Sensitivity will be at least at 10-4 to 10-5 by 10-color MFC. Imaging techniques such as PET-CT are important for EMD and bone MRD detection. whole body DWI-MRI is a new imaging technique by mean of the apparent diffusion coefficient(ADC) which can qualify the depth of response to antineoplastic treatment. This study was designed to evaluate the prognostic significance of MRD by 10-color MFC and imaging to the MM patients after induction.Methods: 102 patients with newly diagnosed MM were enrolled at the First Affiliated Hospital of Soochow University from July 2015 to July 2017. All patients were diagnosed and the response were assessed by IMWG criteria. The median of age was 58 (31-75).There were 46 patients with IgG type , 24 IgA , 14 light chain, 18 others. 34 Patients in ISS stageⅠ,34 in stage Ⅱ, 30 in stage Ⅲ. All patients received 4-6 cycles of triplet bortezomib based or lenalidomide based induction therapy. Transplantation available patients received APBSCT with BUCY condition followed by 4-6 cycles of bortezomib based or lenalidomide based consolidation which were given to transplantation unavailable patients too. Lenalidomide and thalidomide were used for over 2y of maintenance therapy. Bone marrow aspirates for MRD imaging MRD assessment were obtained at the end of induction and 1year after ASCT.The median of follow-up was 13 (2-29) months.Results: According to MRD by MFC and imaging after induction therapy and 1 year after ASCT, the patients were divided into different groups. MFC negativity was 33%(29/88) after induction therapy compared with 63%(32/51) after ASCT (X2=11.636,P=0.001). After induction therapy, the median PFS was 22 months for MRD positive group compared with not reached with MRD negative group by MFC (P=0.042) in patients with very good partial remission(VGPR) and above. The 2 years PFS was 100% for those with MRD negative compared with 60% for MRD positive by imaging. The 2 years PFS was 80% for those have multiclonal normal plasma cells compared with 52.6% for those without. The median PFS was not reached for MFC MRD negative patients 1 year after ASCT compared with 20 months for positive patients. (P=0.002). Multivariate analysis including high risk cytogenetics(17p-, t(4;14), t(14;16)), sex, age, ISS, chemotherapy, ASCT, CR/VGPR, normal PCs showed that the MFC MRD and ASCT were independent prognostic factor.Conclusions: Patients with MFC MRD negative after induction therapy or ASCT is a better prognostic marker than CR or even the best marker. Imaging MRD negativity and the appearance of normal plasma cells in the bone marrow suggests a better prognosis.We will have a try to do more research on overall survival(OS),include longer follow-up and a larger number of patients enrolled. Figure. Figure. Disclosures No relevant conflicts of interest to declare.


Author(s):  
Meera Mohan ◽  
Samantha Kendrick ◽  
Aniko Szabo ◽  
Naveen K Yarlagadda ◽  
Dinesh Atwal ◽  
...  

Multiple myeloma (MM) patients frequently attain a bone marrow (BM) minimal residual disease (MRD) negativity status in response to treatment. We identified 568 patients who achieved BM MRD negativity following autologous stem cell transplantation (ASCT) and maintenance combination therapy with an immunomodulatory agent and a proteasome inhibitor. BM MRD was evaluated by next generation flow cytometry (sensitivity of 10-5 cells) at 3 to 6 months intervals. With a median follow up of 9.9 years from diagnosis (range, 0.4 - 30.9), 61% of patients maintained MRD negativity, while 39% experienced MRD conversion at a median of 6.3 years (range, 1.4 - 25). The highest risk of MRD conversion occurred within the first 5 years after treatment and was observed more often in patients with abnormal metaphase cytogenetic abnormalities (95%vs. 84%; P = 0.001). MRD conversion was associated with a high risk of relapse and preceded it by a median of 1.0 year (range, 0 - 4.9). However, 27% of MRD conversion positive patients had not yet experienced a clinical relapse with a median follow-up of 9.3 years (range, 2.2 - 21.2). Landmark analyses using time from ASCT revealed patients with MRD conversion during the first 3 years had an inferior overall and progression-free survival compared to patients with sustained MRD negativity. MRD conversion correctly predicted relapse in 70%, demonstrating the utility of serial BM MRD assessment to complement standard laboratory and imaging to make informed salvage therapy decisions.


Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 1393-1393
Author(s):  
Jesper Jurlander ◽  
Christian Geisler ◽  
Hans Hagberg ◽  
Harald Holte ◽  
Tuula Lehtinen ◽  
...  

Abstract From 9/98 to 11/99, 126 patients with symptomatic previously untreated or first relapse (&lt; 6 months of chlorambucil and/or local radiotherapy) CD20+ low-grade lymphoma, were included in a multicenter randomised phase II study. The treatment consisted of a first cycle of rituximab 375 mg/sqm q wk x 4. Pts in CR at week 14 were observed with no further treatment until symptomatic relapse, while pts with SD or PD went off study. Pts with PR or minor response were randomised to receive either a second cycle of rituximab 375 mg/sqm q wk x 4 or interferon-alpha-2a (IFN) 3 MIU/day sc (wk 1), 4,5 MIU/day (wk 2–5) in combination with rituximab 375 mg/sqm q wk (w 3–6). The clinical data from this study has previously been reported (Kimby E, et al. Ann Oncol2002;13 (Suppl 2):85). 38 patients (30%) fulfilled the criteria for CR, and were eligible for analysis of minimal residual disease (MRD). 14 more patients achieved CR at a time point later than first follow up after end of treatment. Per protocol, these patients are not included in the present analysis. By standard DNA-based PCR, presence of either a t(14;18) fusion transcript (MCR/mbr) or a clonal rearrangement of the Ig heavy chain (CDR3) could be detected in the diagnostic bone marrow and blood sample from 23 patients. These patients have now been studied for MRD, with a median follow-up time of 62 months. In dilution experiments the sensitivity of the assays was between 1:10−3 and 1:10−4. A given sample was considered negative if the PCR reaction was negative in three independent experiments, using up to 2 μg of template DNA. Patients were tested in blood and bone marrow at 10–16 weeks, 38–40 weeks and 52 weeks following treatment. A total of 175 samples, including 49 samples from patients in continued CR up to 5 years after treatment, have been analysed. Of 72 paired blood and bone marrow samples, only three showed inconsistency between blood and bone marrow, all three being positive in bone marrow and negative in blood. The frequency of MRD negativity 10–16 weeks after treatment was 4/9 (44%) in patients who received 1 cycle of rituximab, 3/5 (66%) in patients who received two cycles of rituximab and 7/9 (77%) in patients who received two cycles of rituximab with IFN priming. This trend towards a dose-response relation was however not significant, due to the small number of patients in each treatment group. The median duration of CR in patients who were negative at all three timepoints during the first year (n=14) was 62 months, compared to 21 months in patients (n=9) with one or more positive samples (p&lt;0,005). At a median follow up of 62 months 9/14 patients who were MRD negative through the first year remain in complete molecular remission, compared to 1/9 patients who had one or more positive blood or bone marrow samples during the first year (p&lt;0,03). Thus, sustained long-term complete molecular remissions are achievable with rituximab alone or in combination with IFN, and predictable by MRD status during the first year post treatment. Whether the quality of response is related to the dose of rituximab or the combination with IFN, and whether the response can be predicted using blood samples alone, must await the results of the ongoing ML16865 randomised phase III trial of rituximab vs IFN/rituximab in the same group of patients.


Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 319-319 ◽  
Author(s):  
Wolfgang Kern ◽  
Claudia Schoch ◽  
Torsten Haferlach ◽  
Daniela Voskova ◽  
Wolfgang Hiddemann ◽  
...  

Quantification of minimal residual disease (MRD) is becoming increasingly important to guide therapy in patients with acute myeloid leukemia (AML). While MFC can be applied to more patients with AML than QPCR, the latter has the advantage of a higher sensitivity in many cases. We compared data obtained by both methods in parallel in bone marrow samples in 160 patients at diagnosis and at 469 follow-up checkpoints. MFC was applied at diagnosis with a comprehensive panel of antibodies to identify leukemia-associated aberrant immunophenotypes (LAIP) useful for MRD monitoring. QPCR targeted on the leukemia-specific fusion transcripts AML1-ETO, AML1-EVI1, CBFB-MYH11, MLL-AF10, MLL-AF6, MLL-AF9, MLL-ELL, MLL-ENL, and PML-RARA as well as overexpression of EVI1, length mutations of FLT3, and partial tandem duplications of MLL. In order to adjust for differences in the percentages of bone marrow cells covered by the respective LAIP by MFC at diagnosis and for the heterogeneity of transcript levels detected by QPCR at diagnosis, the logarithmic difference (LD) was calculated for each follow-up sample in comparison to the diagnostic sample. There was a significant correlation between MFC and QPCR with regard to the LD from diagnosis to follow-up checkpoint (r=0.645, p=0.000001). Concordant results with regard to negativity between QPCR (no signal) and MFC (<0.01% positive cells) was found in 301/469 (64.2%) samples (both methods positive, 270 (57.6%); both methods negative, 31 (6.6%)). In 44 samples (9.4%) QPCR detected positivity and MFC negativity while in 124 samples (26.4%) MFC detected positivity and QPCR negativity (sensitivity of QPCR was lower than 1:100,000 in some cases). In 133 patients clinical follow-up data was available allowing the analysis of the prognostic impact of MRD levels. Cytogenetics were favorable, intermediate, and unfavorable in 86, 30, and 17 cases, respectively. Median age was 46 years (range, 17–83). Median event-free survival (EFS) was 22.1 months, overall survival (OS) at three years was 77%. The median LDs for MFC and QPCR at the checkpoint 1 (up to day 21), 2 (day 22–60), 3 (day 61–120), 4 (day 121–365), and 5 (after day 365) were 2.40 and 0.62, 2.05 and 1.55, 2.51 and 3.34, 2.71 and 3.70, and 2.60 and 3.45, respectively. Separating patients according to these median LDs resulted in a better EFS and OS for cases with higher LDs at all five checkpoints for each method. Significant differences in EFS were observed at checkpoints 2 (MFC, 22.1 vs. 12.6 months, p=0.0379; QPCR, median not reached vs. 9.9, p=0.0081), 3 (QPCR, 30.9 vs. 14.1 months, p=0.0011), 4 (MFC, median not reached vs. 16.9 months, p=0.0007; QPCR, median not reached vs. 15.1 months, p=0.0102), and 5 (QPCR, median not reached vs. 17.2, p=0.0008). Cox regression analysis taking into consideration cytogenetics, age, WBC count, and bone marrow blast count at diagnosis identified the LD at checkpoint 4 determined by MFC and the LD at checkpoints 2 and 5 determined by QPCR as independent prognostic factors. The results of our analyses confirm that both MFC and QPCR are highly sensitive methods capable of quantifying MRD in AML. While data are concordant for both methods in many cases, either of the two has advantages in distinct cases depending on the individual MRD marker. Clinical trials should consider MRD monitoring by both methods in order to prove their respective roles in risk prediction and treatment stratification.


Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 3853-3853
Author(s):  
Yazhen Qin ◽  
Honghu Zhu ◽  
Yan-rong Liu ◽  
Ya-zhe Wang ◽  
Hong-Xia Shi ◽  
...  

Abstract Abstract 3853 Background With the incorporation of more aggressive therapies such as hematopoietic stem cell transplantation (HSCT), more myelodysplastic syndromes (MDS) patients fall into a status of minimal residual disease (MRD). The sensitive molecular markers are required to monitor MRD and predict relapse. The Wilms' tumor gene (WT1) is now a widely accepted molecular marker of MDS. However, WT1 itself could not fully meet the demands because a subset of MDS patients does not overexpress WT1, and the increase of WT1 expression compared with the normal control of MDS patients was mainly within 2-log. We wondered if the preferentially expressed antigen of melanoma (PRAME) gene could supplement WT1. Methods The PRAME and WT1 transcript levels were simultaneously measured in 312 bone marrow samples collected from newly diagnosed MDS patients and 27 samples from non-malignant cytopenia patients. Bone marrow samples from 14 MDS patients after their disease progression were also detected. To evaluate the value of combined detection of WT1 and PRAME transcripts, one hundred and eleven BM samples collected from 17 MDS patients during their treatment were tested them simultaneously (chemotherapy alone: 1 patient; HSCT:16 patients). Bone marrow samples from six MDS patients and five normal controls were sorted into the blasts (CD34+), nucleated erythrocytes (CD71+), immature myeloid cells (CD33+CD34-), and lymphocyte (CD45+high, low SSC) fractions by flow cytometry and measured the PRAME and WT1 transcript levels, respectively. We had previously established that the upper limits of the PRAME and WT1 transcript levels tested in normal bone marrow samples were 0.28% and 0.50%, respectively. Results None of the 27 non-malignant cytopenia patients overexpressed PRAME (median 0.085%, range 0.01%-0.28%) and WT1 (median 0.095%, range 0.0089%-0.36%). Both WT1 and PRAME were commonly overexpressed in MDS. Both the overexpression frequency and the >1-log increase expression frequency of PRAME were similar to those of WT1 (74.4 % vs 77.6%; 51.6% vs 49.0%; p>0.05), and 88.1% of the patients overexpressed at least one marker. Moreover, the frequencies of PRAME expression with higher degrees of increase were significantly higher compared with those of WT1 expression (>2-log increase: 30.8% vs 3.8%; >3-log increase: 9.0% vs 0%; all p<0.001). PRAME had a higher log increase than WT1 in 53.3% of the patients with overexpressed WT1. For samples collected from newly diagnosed MDS patients, both the WT1 and PRAME transcript levels were significantly correlated with the percentage of blasts in bone marrow (r=0.35 and 0.22, all p<0.001). After disease progression, both WT1 and PRAME expressions prominently increased in six patients, only WT1 markedly increased in six patients, only PRAME markedly increased in one patient, and neither WT1 nor PRAME increased in one patient. Both PRAME and WT1 transcript levels generally fluctuated within the normal range after HSCT in all 10 patients in continuous complete remission (PRAME: 58/64 samples, WT1: 58/64 samples). Six out of seven patients were predicted relapse by the combined detection: sustained overexpression or significant increase over the normal range of both WT1 and PRAME in three patients, earlier by PRAME than WT1 or by PRAME alone in three patients. The expression patterns of WT1 differed from those of PRAME in the sorted cell fractions: WT1 is overexpressed in blasts and is significantly decreased in relative mature cells. Whereas, PRAME is mainly overexpressed not only by stem cells and blasts but also by the relative mature cells. Conclusion The combined detection of WT1 and PRAME transcripts in newly diagnosed MDS patients could find more suitable and sensitive molecular marker for them compared to detecting WT1 alone. The PRAME and WT1 transcripts constitute a good molecular marker combination for monitoring minimal residual disease in MDS. Disclosures: No relevant conflicts of interest to declare.


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