Minimal Residual Disease After Allogeneic Stem Cell Transplantation: A Comparison Among Multiparameter Flow Cytometry, Wilms Tumor 1 Expression and Chimerism Status (Complete vs Low-Level Mixed Chimerism) in Patients with Acute Leukemia

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 1971-1971
Author(s):  
Giovanni Rossi ◽  
Angelo Michele Carella ◽  
Maria Marta Minervini ◽  
Lucia Savino ◽  
Andrea Fontana ◽  
...  

Abstract Abstract 1971 Introduction. Relapse represents the main cause of treatment failure after allogeneic stem cell transplantation (allo-SCT). Thus, monitoring of minimal residual disease (MRD) in allografted patients allows an early detection of recurrence and a subsequent intervention prior to florid relapse. Multiparameter Flow Cytometry (MFC), chimerism, cytogenetics and molecular analysis have been widely used for this purpose, although the gold standard needs to be established yet. The evaluation of fusion transcripts represents the most sensitive method but more than 65% of patients do not demonstrate a molecular target. WT1 mRNA is over expressed in > 90% of patients with acute myeloid leukemia (AML) but it is not so expressed in acute lymphoblastic leukemia (ALL). On the MFC analysis instead, the complexity of maturational patterns and phenotypic shifts after therapy may underestimate residual leukemic cells. Finally, previous papers reported that a state of mixed chimerism (MC) in RT-PCR may identify higher risk of relapse in patients with AML. However, the test has a low sensitivity (from 0,1% to 1%) and recipient cells are not necessarily linked to disease recurrence. Hypothesizing the presence of blast cells in the low-level mixed chimerism (MC, 1%<MC<5% of autologous cells) but not in the complete chimerism (CC, no evidence of autologous cells) status, we used these two ranges as markers of positive and negative MRD, respectively. The aim of our study was twofold. Firstly, to assess the overall agreement among chimerism, MFC and WT1 mRNA methods in monitoring MRD. Secondly, to investigate whether such methods were associated to patient' s relapse-free survival. Methods. Fresh BM samples from 24 patients (17 AML and 7 ALL) in both morphological CR and CC or low-level MC status after allo-SCT were investigated. MRD with MFC, WT1 mRNA expression and chimerism analysis was evaluated at different time points: +1, +3, +6,+12,+18,+24 months after allo-SCT. The immunophenotypic analysis was performed using a six-color combinations and acquiring 250.000 events. RQ- PCR to test WT1 mRNA expression was made according to the standardized and quality-controlled method. Chimerism studies were performed with a multiplex amplification of 16 (STR). The agreement between two methods in monitoring MRD after allo-SCT was assessed by Kappa statistic. Moreover, time-to-event analyses were performed using Cox proportional-hazard models with time-dependent covariates. Risks were reported as hazards ratios (HR) along with their 95% confidence interval (95% CI). Results. Comparisons among results of MFC, RQ-PCR for WT1 mRNA and Chimerism were performed in all 67 serial samples obtained from 24 patients. A significant moderate agreement between MFC and WT1 mRNA evaluations was found (k= 0.463, p<0.001) as well as fair agreement between chimerism and MFC (k= 0.284, p=0.009) and chimerism and WT1 mRNA (k= 0.197, p=0.073). These results suggested a concordance among the three investigated techniques. In particular, the low-level MC would well detect the presence of leukemic cells, since the proportion of positive samples for MFC was not statistically different to the proportion of positive samples for WT1 mRNA within samples with low-level MC. Indeed, among 12 samples with low-level MC, 9 samples (75.0%) were also positive for MFC and 7(58.3%) were also positive for WT1 mRNA. Cut-off of 0.1% and 0.01% for MFC, 83.5 × 104 ABL for WT1 mRNA and 96%-99% of donor cells for chimerism were selected. The median follow-up times for relapse-free was 12.8 mths and the overall estimated relapse-free survival after 36 mths was 66.5%. At the end of follow- up, 5 patients relapsed and 4 patients died. Although not significant, the detection of a positive MRD for all methods were associated to a higher incidence of relapse than the negative MRD. Similar HRs were observed in the analysis of MFC(HR = 6.55, 95%CI= 0.71–60.17, p=0.096) and WT1 mRNA (HR= 7.17, 95% CI=0.77–66.42, p=0.083) whilst a slighter HR was found for the chimerism analysis (HR= 0.40, 95%CI= 0.04–4.44, p=0.456). Conclusions. According to our study MFC, WT1 mRNA and CC or low-level MC displayed an overall agreement in monitoring MRD. In particular, the agreement on the low-level MC may suggest the presence of leukemic cells. The detection of a positive MRD by MFC and WT1 mRNA similarly identified higher risk of relapse in patients with acute leukemia (AL) undergone to allo-SCT. Disclosures: No relevant conflicts of interest to declare.

Blood ◽  
2000 ◽  
Vol 96 (12) ◽  
pp. 3948-3952
Author(s):  
Adriano Venditti ◽  
Francesco Buccisano ◽  
Giovanni Del Poeta ◽  
Luca Maurillo ◽  
Anna Tamburini ◽  
...  

We used flow cytometry to quantify minimal residual disease (MRD) in 56 patients with acute myeloid leukemia (AML) expressing a leukemia-associated phenotype. Thirty-four patients aged 18 to 60 years were entered into the AML-10 protocol (induction, consolidation, and autologous stem-cell transplantation [ASCT]), whereas 22 patients older than 60 years received the AML-13 protocol (induction, consolidation, and consolidation II). After induction, the level of MRD that was best associated with treatment outcome was 4.5 × 10−4 residual leukemic cells. However, the outcome in patients with at least 4.5 × 10−4 cells (n = 26) was not significantly different from that in patients with fewer leukemic cells (n = 30); there were 15 (58%) relapses in the first group and 12 (40%) relapses in the second. After consolidation, the most predictive MRD cutoff value was 3.5 × 10−4cells: 22 patients had an MRD level of 3.5 × 10−4 cells or higher and 17 (77%) of these patients had relapse, compared with 5 of 29 patients (17%) with lower MRD levels (P < .001). An MRD level of 3.5 × 10−4 cells or higher after consolidation was significantly correlated with poor or intermediate-risk cytogenetic findings, a multidrug resistance 1 (MDR1) phenotype, short duration of overall survival, and short duration of relapse-free survival (P = .014, .031, .00022, and .00014, respectively). In multivariate analysis, this MRD status was significantly associated with a high frequency of relapse (P < .001) and a short duration of overall (P = .025) and relapse-free survival (P = .007). ASCT did not alter the prognostic effect of high MRD levels after consolidation: the relapse rate after transplantation was 70%. Thus, we found that an MRD level of 3.5 × 10−4 cells or higher at the end of consolidation strongly predicts relapse and is significantly associated with an MDR1 phenotype and intermediate or unfavorable cytogenetic findings.


Blood ◽  
2000 ◽  
Vol 96 (12) ◽  
pp. 3948-3952 ◽  
Author(s):  
Adriano Venditti ◽  
Francesco Buccisano ◽  
Giovanni Del Poeta ◽  
Luca Maurillo ◽  
Anna Tamburini ◽  
...  

Abstract We used flow cytometry to quantify minimal residual disease (MRD) in 56 patients with acute myeloid leukemia (AML) expressing a leukemia-associated phenotype. Thirty-four patients aged 18 to 60 years were entered into the AML-10 protocol (induction, consolidation, and autologous stem-cell transplantation [ASCT]), whereas 22 patients older than 60 years received the AML-13 protocol (induction, consolidation, and consolidation II). After induction, the level of MRD that was best associated with treatment outcome was 4.5 × 10−4 residual leukemic cells. However, the outcome in patients with at least 4.5 × 10−4 cells (n = 26) was not significantly different from that in patients with fewer leukemic cells (n = 30); there were 15 (58%) relapses in the first group and 12 (40%) relapses in the second. After consolidation, the most predictive MRD cutoff value was 3.5 × 10−4cells: 22 patients had an MRD level of 3.5 × 10−4 cells or higher and 17 (77%) of these patients had relapse, compared with 5 of 29 patients (17%) with lower MRD levels (P &lt; .001). An MRD level of 3.5 × 10−4 cells or higher after consolidation was significantly correlated with poor or intermediate-risk cytogenetic findings, a multidrug resistance 1 (MDR1) phenotype, short duration of overall survival, and short duration of relapse-free survival (P = .014, .031, .00022, and .00014, respectively). In multivariate analysis, this MRD status was significantly associated with a high frequency of relapse (P &lt; .001) and a short duration of overall (P = .025) and relapse-free survival (P = .007). ASCT did not alter the prognostic effect of high MRD levels after consolidation: the relapse rate after transplantation was 70%. Thus, we found that an MRD level of 3.5 × 10−4 cells or higher at the end of consolidation strongly predicts relapse and is significantly associated with an MDR1 phenotype and intermediate or unfavorable cytogenetic findings.


Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 2298-2298
Author(s):  
Andrea Corbacioglu ◽  
Claudia Scholl ◽  
Karina Eiwen ◽  
Lars Bullinger ◽  
Stefan Frohling ◽  
...  

Abstract Detection of minimal residual disease (MRD) in acute myeloid leukemia (AML) associated with specific gene fusions is an important tool for the assessment of response to treatment and the individual risk of relapse. The real-time quantitative RT-PCR (RQ-PCR) method allows the quantification of fusion transcript levels at distinct time points during treatment. While in acute promyelocytic leukemia (APL) MRD monitoring has been clearly shown to be predictive for clinical outcome, the prognostic value of MRD in CBFB-MYH11 AML could not consistently been demonstrated yet. Small patient populations and the availability of bone marrow (BM)/peripheral blood (PB) samples at defined time points mainly hamper most studies. We evaluated the prognostic impact of MRD in a large cohort of CBFB-MYH11 AML by RQ-PCR. A total of 44 patients (16–60 years) were treated within one of the AMLSG treatment trials (AMLHD93 n=4, AMLHD98A n=27, AMLSG07-04 n=13). Patient samples (BM and/or PB) were collected at study entry (n=75), during treatment (n=199), and during follow up (n=140). Following high-dose cytarabine (HiDAC) consolidation therapy, patients received a second course of HiDAC (n=25); autologous stem cell transplantation (SCT) (n=13) or allogeneic SCT from a matched related family donor (n=6) depending on the treatment protocol. Median follow up was 22.5 months. Quantitative CBFB-MYH11 fusion transcript expression was measured by RQ-PCR using TaqMan technology. Primers and probes were chosen according to Europe Against Cancer (EAC) standard protocols. Sensitivities ranged from 10−3 to 10−4.Transcript levels at diagnosis ranged from 6208 to 312987 (median 34293.5). There was no prognostic impact of pretreatment transcript levels on relapse free survival (RFS). The ratio of transcript levels after 2 induction cycles and pretreatment levels ranged from 0 to 0.0049; again, this ratio had no impact on RFS. In contrast, during consolidation therapy 63% of the patients became RQ-PCR negative and RFS was significantly superior (RFS after 2 years 75%) compared to RQ-PCR positive patients (RFS after 2 years 32%) (p=0.03). After consolidation, seven of the RQ-PCR negative patients became positive at least in one BM-sample during follow up. Four patients developed transcript levels above 10 and all relapsed, whereas the three patients with transcript levels remaining below 10 are in continuous remission (p=0.0001). In our study, transcript levels during and after consolidation therapy are significantly associated with clinical outcome in CBFB-MYH11 AML. Risk-adapted therapy may be considered for those patients remaining positive during consolidation therapy. The identification of transcript levels above 10 after consolidation therapy might allow early treatment decisions.


Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 4639-4639
Author(s):  
Florence Beckerich ◽  
Mohamad Sobh ◽  
Stephane Morisset ◽  
Adriana Plesa ◽  
Valerie Dubois ◽  
...  

Background Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a potential curative strategy for acute myeloid leukemia (AML) patients in complete remission (CR) presenting poor prognostic factors or with relapsed/refractory disease. However, the risk for disease recurrence following allo-HSCT remains significant and associated with poor outcomes. After transplantation, the early detection of minimal residual disease (MRD) using immunophenotyping combined to chimerism documentation before morphological relapse may allow for immediate interventions and can lead to better results. Immunophenotyping using Multiparameter Flow Cytometry (MFC) and chimerism documentation by PCR have been widely used to track disease recurrence, although a validated consensus on the use of these techniques in the post-allo-HSCT follow-up has not been established yet. The aim of our study was to evaluate the impact of positive MRD by MFC associated to chimerism documentation at 3 months after allo-HSCT on patients overall and progression-free survival (OS, PFS). Patients and Methods We evaluated 137 AML patients who received allo-HSCT in a single center between January 2005 and October 2012 at our department and for whom a 3 months MRD evaluation and chimerism documentation has been performed using MFC, and PCR analysis. There were 71 (52%) males and 66 females with a median age of 47 years (range: 19-66), 77% had de novo AML, 20% had secondary AML and 3% had biphenotypic AML. According to cytogenetics, 40% were normal, 51% were unfavorable (9% classified as failure). According to molecular markers, 9% were favorable, 31% intermediate, 44% unfavourable and 16% had no molecular markers. At allo-HSCT, 46% of patients were in first complete remission (CR1), 25% were in CR 2 and 29% had active disease; 40% received a full intensity conditioning and 60% got reduced intensity one. As cell source, 35% were bone marrow, 53% peripheral blood and 12% cord blood cells. Donors were related in 53% of the cases (45% were 10/10 HLA matched) and unrelated in 47% of cases (20% were 10/10 HLA matched). MFC was performed using BM samples with a sensitivity of 0.01%. Chimerism analysis was performed on marrow and/or blood samples using polymerase chain reaction (PCR) based on informative polymorphic short tandem repeat with an accuracy of ± 5%, a mixed chimerismwas defined by having 5% or more of recipient cells. Results After transplantation, all patients engrafted, the cumulative incidence of acute GVHD at 3 months was 19.9% (95% CI: 16.2-20.6) while the cumulative incidence of chronic GVHD reached 26.7% (95% CI: 22.9-30.5) at 1 year. After a median follow-up of 16 months (range: 3-77), the median OS was 66 months (65-NR) with a 3 years probability of 64% (95% CI: 56-73), the median PFS was 32 months (13-NR) with a 3 years probability of 50% (95% CI: 37-58) while the transplant related mortality rate reached 13.6% (95% CI: 10-16) at 2 years. The 3 months chimerism evaluation (n=137) showed a mixed chimerism in 12 (9%) patients, while the MFC (n= 62) detected 15 patients with leukemic cells. Sixty eight patients showed morphological relapse after a median time of 4.8 months (1-34.7); the correlation study between MRD positivity, mixed chimerism detection and morphological relapse showed a higher correlation for both chimerism and MFC (correlation=0.69, p<0.001) than if we consider chimerism or MFC alone. Multivariate analysis showed a significant worse OS for patients with 3 months positive MFC [1 year OS of 20% vs. 80%, HR= 4 (95% CI: 1.4-11.7), p=0.01] and patients with mixed chimerism [1 year OS of 21% vs. 70%, HR= 4 (95%CI: 1.3-12.1), p=0.01]; these results were still valid even after stratification on disease status at transplantation. These results applied also in terms of PFS for positive MFC [1 year PFS of 13% vs. 76%, HR= 3.6, p=0.02], and mixed chimerism[1 year PFS of 0% vs. 70%, HR= 7, p=0.001], Figure 1. Conclusion The 3 months MRD evaluation using MFC combined to chimerism documentation seems to be an independent prognostic factor on overall and progression-free survival for AML patients undergoing allo-HSCT. The standardisationof this evaluation may lead to the identification of patients with high relapse risk suggesting the need of early therapeutic intervention. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
1997 ◽  
Vol 90 (6) ◽  
pp. 2465-2470 ◽  
Author(s):  
J.F. San Miguel ◽  
A. Martı́nez ◽  
A. Macedo ◽  
M.B. Vidriales ◽  
C. López-Berges ◽  
...  

Abstract A high complete remission rate is currently achieved in patients with acute myeloid leukemia (AML). However, many patients eventually relapse due to the persistence of low numbers of residual leukemic cells that are undetectable by conventional cytomorphologic criteria (minimal residual disease [MRD]). Using immunophenotypic multiparametric flow cytometry, we have investigated in sequential studies (diagnosis and follow-up) the impact of MRD detection on the outcome of 53 AML patients that had achieved morphologic remission with standard AML protocols and displayed at diagnosis an aberrant phenotype. Patients were studied at diagnosis with a panel of 35 monoclonal antibodies in triple staining combinations for detection of aberrant or uncommon phenotypic features. According to these features, a patient's probe was custom-built at diagnosis for the identification of possible residual leukemic cells during follow-up. The level of MRD at the end of induction and intensification therapy correlated with the number of relapses and relapse-free survival (RFS). Thus, patients with more than 5 × 10−3 residual cells (5 residual cells among 1,000 normal bone marrow [BM] cells) identified as leukemic by immunophenotyping in the first remission BM showed a significant higher rate of relapse (67% v 20% for patients with less than 5 × 10−3 residual cells; P = .002) and a lower median RFS (17 months v not reached; P = .01). At the end of intensification, with a cut-off value of 2 × 10−3 leukemic cells, AML patients also separated into two distinct groups with relapse rates of 69% versus 32% (P = .02), respectively, and median RFS of 16 months versus not reached (P = .04). In addition, overall survival was also significantly related to the level of residual cells in the marrow obtained at the end of induction and particularly after intensification therapy (P = .008). Furthermore, we have explored whether residual disease was related with the functional expression of multidrug resistance (MDR-1) at diagnosis as assessed by the rhodamine-123 assay. Patients with ≥5 × 10−3 residual leukemic cells at the end of induction therapy had a significantly higher rhodamine-123 efflux (mean, 56% ± 24%) than those with less than 5 × 10−3 residual cells (mean, 32% ± 31%; P = .04). Finally, multivariate analysis showed that the number of residual cells at the end of induction or intensification therapy was the most important prognostic factor for prediction of RFS. Overall, our results show that immunophenotypical investigation of MRD strongly predicts outcome in patients with AML and that the number of residual leukemic cells correlates with multidrug resistance.


2017 ◽  
Vol 35 (16) ◽  
pp. 1795-1802 ◽  
Author(s):  
Giovanni Martinelli ◽  
Nicolas Boissel ◽  
Patrice Chevallier ◽  
Oliver Ottmann ◽  
Nicola Gökbuget ◽  
...  

Purpose Few therapeutic options are available for patients with Philadelphia chromosome–positive (Ph+) B-precursor acute lymphoblastic leukemia (ALL) who progress after failure of tyrosine kinase inhibitor (TKI) −based therapy. Here, we evaluated the efficacy and tolerability of blinatumomab in patients with relapsed or refractory Ph+ ALL. Patients and Methods This open-label phase II study enrolled adults with Ph+ ALL who had relapsed after or were refractory to at least one second-generation or later TKI or were intolerant to second-generation or later TKIs and intolerant or refractory to imatinib. Blinatumomab was administered in 28-day cycles by continuous intravenous infusion. The primary end point was complete remission (CR) or CR with partial hematologic recovery (CRh) during the first two cycles. Major secondary end points included minimal residual disease response, rate of allogeneic hematopoietic stem-cell transplantation, relapse-free survival, overall survival, and adverse events (AEs). Results Of 45 patients, 16 (36%; 95% CI, 22% to 51%) achieved CR/CRh during the first two cycles, including four of 10 patients with the T315I mutation; 88% of CR/CRh responders achieved a complete minimal residual disease response. Seven responders (44%) proceeded to allogeneic hematopoietic stem-cell transplantation, including 55% (six of 11) of transplantation-naïve responders. Median relapse-free survival and overall survival were 6.7 and 7.1 months, respectively. The most frequent AEs were pyrexia (58%), febrile neutropenia (40%), and headache (31%). Three patients had cytokine release syndrome (all grade 1 or 2), and three patients had grade 3 neurologic events, one of which (aphasia) required temporary treatment interruption. There were no grade 4 or 5 neurologic events. Conclusion Single-agent blinatumomab showed antileukemia activity in high-risk patients with Ph+ ALL who had relapsed or were refractory to TKIs. AEs were consistent with previous experience in Ph– ALL.


Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 2989-2989
Author(s):  
Granada Perea ◽  
Adriana Lasa ◽  
Anna Aventin ◽  
Alicia Domingo ◽  
Neus Villamor ◽  
...  

Abstract Objectives: To analyze MRD in 65 patients (pts) with good prognosis AML: 30 t(8;21) and 35 inv(16), using both FC and RT-PCR, and to investigate the prognostic value of MRD in the pts outcome. Methods: MRD was monitored in CR pts (n=55) by FC in 101 follow-up samples obtained after various cycles of treatment, as follows: 40 post-induction (ind), 30 post-intensification (int) and 31 at the end of treatment (ttm), and by RT-PCR in 76 samples: 31, 23 and 22, respectively. In 35 pts the two techniques were applied at the same time of the ttm. MRD by FC was assessed using fixed combinations of three monoclonal antibodies. AML1/ETO and CBFb/MYH11 were analyzed following the BIOMED protocol. Results: Twenty-seven percent (n=15) of CR pts relapsed: 6 with t(8;21) and 9 with inv(16). The mean MRD by FC was 1.1% after ind, 0.2% after int and 0.1% at the end of ttm. At the end of ttm, the MRD detected by FC in relapsed and not relapsed pts were significativaly different: 0.3% vs 0.08% (p=0.002). By RT-PCR, the mean of fusion transcript copies/ablx104 differed between relapsed and nonrelapsed pts: 2385 vs 122 (p=0.001) after ind, 56 vs 7.6 after int (p=0.0001) and 75 vs 3.3 (p=0.0001) at the end of ttm. Relapses were more commonly observed in those pts with FC MRD level >0.1% at the end of ttm than in pts with ≤0.1%: 50% vs 12% (p=ns); likewise, using RT-PCR, a cutoff level of >10 copies at the end of ttm correlated with high risk of relapse: 80% of pts with RT-PCR >10 relapsed compared to 12% of pts with levels <10 (p=0.009). The overall survival (OS) probability was 86% for pts with CF MRD ≤0.1 at the end of ttm and 0% for pts with MRD >0.1 (p=0.1) and the leukemia free survival (LFS) was 78% and 44%, respectively (p=0.05). For pts with RT-PCR ≤10 at the end of ttm, the OS was 100% and for pts with RT-PCR >10 it was 30% (p=0.007) and the LFS was 87% and 20%, respectively (p=0.001). MRD was identified after ind in 55% of relapsed pts and at the end of ttm in 83% of relapsed pts. Only 1 pt (1/13) with FC MRD <0.1 and RT-PCR <10 at the end of ttm relapsed. For patients in complete remission, the mean copy level of chimeric transcript was higher for pts with t(8;21) than for those with inv(16): 30.2 vs 17.4 (p=0.0001). Comments: In tandem analysis of MRD by FC and RT-PCR could improve MRD detection in AML pts.


Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 400-400 ◽  
Author(s):  
Wolfgang Kern ◽  
Daniela Voskova ◽  
Claudia Schoch ◽  
Wolfgang Hiddemann ◽  
Susanne Schnittger ◽  
...  

Abstract Guiding antileukemic treatment in patients with acute myeloid leukemia (AML) is increasingly based on levels of minimal residual disease (MRD) which can be quantified with high sensitivity by multiparameter flow cytometry (MFC). The optimum checkpoint for determination of MRD during the course of therapy, however, has not yet been determined. We applied MFC using a comprehensive panel of antibodies to identify leukemia-associated aberrant immunophenotypes (LAIPs) at diagnosis and to quantify MRD by individually selected antibody combinations. The prognostic impact of MRD levels was assessed in comparison to cytogenetics and age. Patients received double induction, consolidation, and maintenance therapies and underwent allogeneic stem cell transplantation if they were younger than 60 years and had a matched related donor. In 286 patients with newly diagnosed and untreated AML MFC-based assessment for the presence of LAIP has been performed. The median percentage of LAIP-positive bone marrow cells at diagnosis was 16.04% (range, 2.54%–76.14%). All individual LAIPs were applied to 26 normal bone marrow samples to estimate sensitivity based on the median percentages of LAIP-positive normal bone marrow cells which ranged from 0.00% to 1.01% (median, 0.02%). A total of 550 follow-up samples has been analyzed in these patients at different checkpoints (CP1, up to day 21 after start of therapy, n=85; CP2, day 22–60, n=122; CP3, day 61–120, n=158; CP4, day 121–365, n=137; CP5, after day 365, n=48). In order to adjust for differences in the percentages of LAIP-positive bone marrow cells at diagnosis the logarithmic difference (LD) between diagnosis and follow-up was calculated for each follow-up sample. The median LDs at the respective checkpoints were: CP1, 2.02; CP2, 2.29; CP3, 2.39; CP4, 2.53; and CP5, 2.81. Separation of patients according to the respective median LDs resulted in differences in event-free survival (EFS; CP1: 21.1 vs. 9.1 months, p=0.0711; CP2: 14.2 vs. 9.3 months, p=0.0095; CP3: 30.9 vs. 13.5 months, p=0.0055; CP4: median not reached vs. 14.1 months, p<0.0001; CP5: median not reached vs. 22.5 months, p=0.0001) and overall survival (OS; CP3: median not reached vs. 21.6 months, p=0.0332; CP4: 90% vs. 53% at 2 years, p=0.0058). Cox analysis using the LDs at the different checkpoints as continuous variables confirmed the prognostic impact on EFS (CP2, p=0.002; CP3, p=0.0003; CP4, p<0.0001; CP5, p<0.0001) and revealed an impact also on OS (CP3, p=0.003; CP4, p=0.001; CP5, p=0.029). Cox regression analysis taking into consideration cytogenetics and age as covariates proved the independent prognostic impact of LD at checkpoints 2 to 5 on both EFS and OS with the exception of LD at checkpoint 2 and OS. In fact, LD at checkpoint 5 was the only parameter independently related to EFS and OS. These data suggest that quantification of MRD by MFC in AML results in powerful and independent prognostic parameters. In particular during the first year of treatment MRD levels provide important prognostic information. Clincal trials should use MRD-based stratification in order to assess the efficacy of early treatment intensification in high-risk AML patients.


Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 1521-1521 ◽  
Author(s):  
Mikhail Roshal ◽  
Jonathan Fromm ◽  
Stuart Winter ◽  
Kimberly Dunsmore ◽  
Brent Wood

Abstract Immunophenotyping has become a primary modality in detection of minimal residual disease (MRD) in acute leukemia. Detection and enumeration of leukemic blasts relies on the recognition of the aberrancies in the immunophenotype of the abnormal population. Antigens associated with immature phenotype are thought to represent particularly good markers for identification of leukemic cells. In particular the expression of terminal deoxynucleotide transferase (TdT) on the T-lineage blasts outside the thymus and aberrantly high expression CD99 have been shown to be present in virtually all cases of T-ALL at diagnosis. CD34 and CD10 have also been used as markers of immaturity and aberrancy in MRD. Upon therapy precursor B cell ALL blasts have been shown to lose markers associated with immaturity complicating the detection of MRD. Immunophenotypic changes in T-ALL have not been well characterized. We studied the utility of these markers in the detection of MRD in pediatric patients undergoing chemotherapy under the Children’s Oncology Group (COG) research protocol for treatment of T-ALL. Per protocol (COG-AALL0434) patients received cytarabine intrathecally (IT) on day 1; vincristine IV and daunorubicin hydrochloride IV on days 1, 8, 15, and 22; prednisone IV or orally twice daily on days 1–28; pegaspargase intramuscularly (IM) on day 4, 5, or 6; and methotrexate (MTX) IT on days 8 and 29. Blood and bone marrow samples from 74 consecutive patients enrolled in the protocol between 05/2007 and 04/2008 and who had at least one positive sample (&gt;0.1% blasts of total white cells) at days 8, 15 or 29 post first day of induction were analyzed at diagnosis and in the setting of MRD detection for abnormal expression of TdT, CD99, CD34 and CD10 by multiparameter flow cytometry. Expression of individual antigens was assessed both by percentage of the leukemic blasts with levels of expression above those of normal mature T cells in the samples and by mean fluorescence quotient relative to normal T cells. Consistent with prior reports, nearly all patient samples demonstrated expression of TdT (96%, MFQ=1.35(central 95%=1.01–1.74)) and high expression of CD99 (96%, MFQ=1.34(1.01–1.59)) on at least 20% of abnormal cells at diagnosis. Moreover, TdT and CD99 could be used for blast enumeration with 88% of cases showing greater than 50% positivity for each marker. Expression of these markers began to decline by day 8 and continued to decrease through day 29. Thus only a minority of positive cases showed expression of TdT (24%, MFQ=1.08(0.9–1.62), p&lt;0.001, by Wilcoxon signed-rank test) or CD99 (44%, MFQ=1.14 (0.88–1.51) p&lt;0.001) and in yet smaller proportion of cases could these markers be used for blast enumeration (11% and 26% respectively) by day 29. Median decline for CD99 positivity on the abnormal blasts was 24%, 26% and 62% at day 8, 15 and 29 respectively. Similarly, the differences for TdT were 30%, 44% and 60% respectively. CD34 and CD10 were expressed on a minority of pre-treatment cases (41% and 28% respectively) and expressed similar but less dramatic decline. At day 29, 25.9% of cases expressed CD34 and 16.2% of cases expressed CD10. Median change was 16% for CD34 and 17% for CD10 for cases that expressed those antigens before treatment. Figure 1 demonstrates the declines in both “high positive” with abnormal blasts showing greater than 50% positivity for a marker and of “low positive” cases showing between 20–50% positivity. We conclude that expression of common T-ALL markers of immaturity dramatically declines in the setting of chemotherapy, reducing their value for immunophenotypic detection of MRD. We speculate that this change is due to either chemotherapy induced partial maturation or selective survival of more mature aberrant cells. These results suggest the need for expansion of immunophenotyping panels to decrease reliance on individual markers of immaturity for T-ALL detection in order to achieve a more accurate evaluation of MRD. Figure 1: Loss of markers of immaturity in T-ALL Figure 1:. Loss of markers of immaturity in T-ALL


Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 3269-3269
Author(s):  
Iwona Solarska ◽  
Barbara Nasilowska-Adamska ◽  
Maria Bieniaszewska ◽  
Jan Maciej Zaucha ◽  
Piotr Rzepecki ◽  
...  

Abstract Abstract 3269 Poster Board III-1 Allogeneic hematopoietic stem cell transplantation (alloHSCT) is a potentially curative treatment for patients (pts) with chronic myeloid leukemia (CML). AlloHSCT is associated with long-term disease-free survival in 40% to 80% pts transplanted in early chronic phase of disease. The probability of relapse for pts transplanted in first chronic phase is 10% to 20% at 5 years, and is even higher (30% – 60%) for pts who received transplant in advanced phases of CML. The significance of minimal residual disease (MRD) in this clinical setting is uncertain. We enrolled 63 consecutive pts with CML who had received an alloHSCT between 1995 and 2007 and had BCR-ABL transcript quantity measured by RQ-PCR method on at least 2 occasions during follow-up in the period starting 6 months after alloHSCT. The reverse transcription was preformed using SuperScriptIII and random hexamers. Quantification of BCR-ABL was performed by RQ-PCR assay according to ‘Europe Against Cancer' protocol. BCR-ABL expression was normalized with endogenous control ABL gene and expressed as a ratio BCR-ABL/ABL. According to the amount of BCR-ABL transcript detected in blood or bone marrow after alloHSCT pts were allocated into 3 categories, including pts with no-detectable or stable very low-level of BCR-ABL transcripts (ratio BCR-ABL/ABL below 0.005%), pts with fluctuating-low level of BCR-ABL transcripts (0.005 – 0.01%) and pts with high-level of BCR-ABL transcripts (0.01 – 0.1%). We didn't find any relationships between different BCR-ABL levels after alloHSCT and clinical parameters at the time of CML diagnosis or transplantation, including Sokal, Hasford and Gratwohl scores. Median time from alloHSCT to molecular relapse (MR) was 38 months (range, 8.5 – 88.5 months). The 3-year progression rate into cytogenetic or hematological relapse of CML since MR was 70%. This progression occurred at a median time of 1.4 months (range, 0 – 3.2 months). We found strong correlation between the levels of BCR-ABL transcripts after alloHSCT and a risk of relapse. The incidence of MR was 0%, 26%, 71% for the low-level, fluctuating-low level and high-level of BCR-ABL transcript (p<.0001), respectively. Similarly the risk of cytogenetic and hematological relapse was 0%, 21%, 43% for these pts (p=.001), respectively. Five-year leukemia-free survival was 100%, 83.9% and 66.7% for the pts with low-level, fluctuating-low level and high-level BCR-ABL transcript (p=.003), respectively. There was no apparent relationship between the level of BCR-ABL transcript and overall survival. We conclude that pts with fluctuating-low and/or high levels of BCR-ABL transcripts are at higher risk of disease progression. Sequential RQ-PCR monitoring coupled with pre-emptive therapy can provide a valid strategy to reduce rates of relapse and development of a more individualized approach to management of pts with CML in major molecular response after alloHSCT. Disclosures: Warzocha: BMS: Consultancy, Honoraria; Celgene: Consultancy; Roche: Honoraria; Pfizer: Honoraria; Amgen: Honoraria.


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