scholarly journals Analysis of Molecular Minimal Residual Disease in Patients with Acute Leukemia during Complete Remission

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 2781-2781
Author(s):  
Yang Zhang ◽  
Fang Wang ◽  
Xue Chen ◽  
Yu Zhang ◽  
Mingyu Wang ◽  
...  
Keyword(s):  
Complete Remission ◽  
Acute Leukemia ◽  
Prognostic Value ◽  
Residual Disease ◽  
Gene Mutations ◽  
Sustained Remission ◽  
Variant Allele Frequency ◽  
Ras Pathway ◽  
Minimal Residual

Abstract Introduction: Acute leukemia is a group of clonal heterogeneous diseases with high recurrence rate. The monitoring of minimal residual disease (MRD) after treatment mainly relies on flow cytometric immunophenotyping. Genetic abnormalities as the basis of the development of leukemia, the prognosis value of gene mutations in complete remission (CR) has yet to be established except for NPM1 and FLT3-ITD mutations. Recent studies have reported that persistent mutations in non-DNMT3A, TET2, and ASXL1 (DTA) mutations during CR had significant independent prognostic value with respect to relapse and survival rates, but the detection of persistent DTA mutations did not have such prognostic value (Jongen-Lavrencic M et al., N Eng J Med 2018). In this study, we analyzed the molecular MRD of mutations in 58 genes during CR in patients with acute leukemia and explored its impact on prognosis. Methods: Amplicon-targeted, next-generation sequencing (IonTorrent PGM platform, Thermo Fisher Scientific) of 58 genes that are frequently mutated in hematological malignancies was performed retrospectively on 202 patients of acute leukemia, including 117 cases of AML (median age, 23 years; rang, 1-65 years), 66 cases of B-ALL (median age, 13.5 years; rang, 1-45 years) and 19 cases of T-ALL (median age, 11 years; rang, 1-42 years). The average sequencing depth was 1000x. A minimum coverage of 100x and a variant allele frequency >5% were used as thresholds for calling variants. Results: Mutations presented in 8.5% (10/17) of AML patients during CR and the variant allele frequency (VAF) ranged from 5.0% to 25.5% (median VAF, 12%), of which 80% (8/10) were epigenetic regulator gene mutations (DNMT3A, TET2, and IDH1/2). DNMT3A mutation (R882 locus) were detected in five cases, IDH2 mutation (R140Q) were detected in two cases, IDH1 (R132C), TET2 (C1211Y), KIT (D816H), NPM1 (W288Cfs*12), and U2AF1 (S34F) mutation were each presented in one case. There were four cases with DTA and non-DTA mutations respectively and two cases concomitant with DTA and non-DTA mutations (one with DNMT3A and IDH1 mutations and another one with DNMT3A and NPM1 mutations). The median age of four patients with DTA mutations was 45 years (rang, 22-54 years), and the median follow-up time was 15 months (rang, 10-19 months). Among them, three cases were relapsed, two of the three patients who underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT) were relapsed. The median age of four patients with non-DTA mutations was 24.5 years (rang, 12-64 years), and the median follow-up time was 25.5 months (rang, 12-35 months). All the patients with non-DTA mutations underwent allo-HSCT and were in continuous CR. One of the two patients who concomitant with DTA and non-DTA mutations (mutation in DNMT3A and IDH1) relapsed after allo-HSCT. Mutations presented in two cases of B-ALL patients during CR, of which PTPN11 (H520Y, VAF 5.9%) mutation was identified in one case who achieved MRD-negative after one course of induction and three courses of consolidation chemotherapy and in a state of sustained remission for two years after allo-HSCT at the time of reporting. KRAS (G12S, VAF 6.3%) mutation was identified in another case whose MRD persists positively after multiple courses of chemotherapy and relapsed in the third years after chemotherapy. At the time of reporting, the bone marrow is in a state of sustained remission for eight months after allo-HSCT. No mutations were detected in all T-ALL patient during CR. Conclusion: Mutations in the epigenetic regulators DNMT3A, TET2, and IDH1/2 are most common in patients with AML during complete remission and the majority of mutations in genes related to the RTK/RAS pathway were cleared. DTA mutations are more common in older patients. The recurrence rate after allo-HSCT is higher in patients with DTA mutation than that of patients with non-DTA mutation and which need to be further verified in the expanded cohort due to the limited number of cases in this study. In contrast to AML, mutations detected in B-ALL during complete remission were mainly RAS pathway and its prognostic significance needs to be further studied. Disclosures No relevant conflicts of interest to declare.

scholarly journals Improving the Definition of Response Assessment: Prognostic Value of Minimal Residual Disease Combined with PET/CT at Day 100 Post Autologous Stem Cell Transplantation in Multiple Myeloma

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 33-34
Author(s):  
Miguel Gonzalez-Velez ◽  
Mariano Arribas ◽  
Heidi E. Kosiorek ◽  
Richard Butterfield ◽  
Carlo Guerrero ◽  
...  
Keyword(s):  
Board Of Directors ◽  
Prognostic Value ◽  
Residual Disease ◽  
High Sensitivity ◽  
Response Assessment ◽  
Advisory Committees ◽  
Pet Ct ◽  
Definition Of ◽  
Minimal Residual

Introduction: Response assessment at day 100 post Autologous Stem Cell Transplant (ASCT) is associated with long-term relapsed free survival (RFS) and overall survival (OS) in multiple myeloma (MM). The International Myeloma Working Group (IMWG) are the preferred criteria to define best response to treatment and define relapse. In the last years, response assessment has incorporated minimal residual disease (MRD) status -associated with improved RFS and OS (Munshi et al); and PET/CT combined with clinical characteristics -also associated with favorable outcomes (Zamagni et al. NCT01910987; MMY3033). The 2016 IMWG MRD criteria, combined imaging (PET/CT) plus next-generation sequencing (NGS) MRD-negative to define complete response (CR). To our knowledge, there is limited data examining the correlation and prognostic value of MRD and FDG-PET/CT at day 100 post ASCT in MM. IN this study, we aimed to determine the prognostic valued of MRD by NGS combined with PET/CT in RFS and OS status after high dose chemotherapy and ASCT in MM. Methods: Patients who underwent ASCT for MM at Mayo Clinic Arizona and had MRD and PET/CT data were included in the study. Clinical data was obtained via retrospective chart review. Cytogenetic risk (CyR) was classified using the mSMART criteria . Disease and ASCT related characteristics were compared by MRD status. MRD was measured by NGS on bone marrow aspirates using the previosly validated clonoSEQ ® Assay (Adaptive Biotechnologies Corporation, Seattle, USA) tracking the IgH, IgK and IgL rearrangements at a minimum sensitivity level of 10-5. MRD was defined by residual clonal cells per million nucleated cells as: negative= 0, borderline= 1-5, positive >5. PET/CT scans were performed locally at baseline and at day 100. Comparisons were performed using the chi-square test for categorical variables, Wilcoxon rank-sum test for continuos variables, McNemar's test and Cohens's Kappa for agreement measures. Results: A total of 103 patients had matched MRD and PET/CT assessment around day 100 (+/-9 days) and were included in the analysis. Median age at diagnosis was 62 years (range, 54-66 years), 71 patients (68.9%) were men. CyR was standard risk in 49 (47.6%), high-risk in 39 (37.9%) and unknown in 15 (14.6%) patients. Most 75 (72.8%) patients were MRD positive, 16 (15.5%) were MRD negative, and 12 (11.7%) borderline. The median main MRD clone detected was 64 (range 0-91,874). 70 patients (68%) and 33 (32%) had a negative and positive PET/CT respectively. The median follow-up time was 18 months (range, 13-31 months). At the time of data analysis, 10 patients (9.7%) had relapsed and only 4 (3.9%) had died. There was a high-correlation between MRD status and PET/CT, 31 patients (93.9%) with positive PET/CT were also MRD positive (p=0.0027). There were no statistical differences between PET/CT and CyR (p=0.95). We analyzed the correlation using the FREQ procedure (McNemars's test); there was a strong association between positive PET/CT and positive MRD in 31/33 patients (93.9%, high sensitivity), and low association for negative PET/CT the negative/borderline MRD in 26/70 (37.1%, low specificity; p<0.001). The agreement measure between the PET/CT and MRD using negative/borderline combined had a kappa of 0.23 (95% CI 0.11, 0.35) indicating a fair agreement beyond chance (Figure 1). PET/CT-CT was a statistically significant predictor of worse RFS (HR 3.53, 95%CI: 1.02-12.24, p<0.0337) and OS (HR 11.38, 95%CI: 1.18-109.56, p<0.0078) (Figure 2-3, respectively). MRD was not predictive of neither RFS (HR 1.72, 95%CI: 0.36-8.14, p<0.49) or OS (p<0.16). Conclusions: In conclusion, we demonstrate that the combination of MRD by NGS (clonoSEQ ®) and PET/CT at day 100 are complementary and have a high sensitivity (true positive rate) and fair correlation of agreement but low specificity (true negative rate). PET/CT was the best most sensitive technique to prognosticate RFS and OS. We did not find prognostic correlation of MRD with RFS and OS. However, our findings might be confounded by the low risk of relapse and death, a longer follow-up may demonstrate clinically important differences. Our results add evidence that MRD plus PET/CT improve the definition of CR in MM patients post ASCT. Prospective studies are needed to elucidate the optimal timing and role of combined MRD, PET/CT with other prognostic markers of clinical outcomes. Disclosures Larsen: Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen Oncology: Honoraria, Membership on an entity's Board of Directors or advisory committees. Fonseca:Juno: Consultancy; Kite: Consultancy; Aduro: Consultancy; OncoTracker: Consultancy, Membership on an entity's Board of Directors or advisory committees; Merck: Consultancy; Bayer: Consultancy; Janssen: Consultancy; Takeda: Consultancy; Novartis: Consultancy; Pharmacyclics: Consultancy; Sanofi: Consultancy; Oncopeptides: Consultancy; GSK: Consultancy; AbbVie: Consultancy; Adaptive Biotechnologies: Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy; BMS: Consultancy; Celgene: Consultancy.

scholarly journals Prognostic Value of Minimal Residual Disease before Allogeneic Hematopoietic Stem Cell Transplantation in Patients with Acute Myeloid Leukemia

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 5733-5733
Author(s):  
Olga Pérez-López ◽  
Teresa Caballero-Velázquez ◽  
Enrique Colado ◽  
Sara Alonso ◽  
José González-Campos ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Prognostic Value ◽  
Residual Disease ◽  
Hematopoietic Stem ◽  
Multiparametric Flow Cytometry ◽  
Minimal Residual ◽  
Acute Myeloid

Abstract Introduction Several studies have shown that the minimal residual disease (MRD) in acute myeloid leukemia (AML) patients has a prognostic value after induction and consolidation therapy. Nevertheless the relapse is the most important cause of treatment failure in these patients, although they achieved a negative MRD, and even after an allogeneic hematopoietic stem cell transplantation (allo-HSCT). Nowadays, the value of the MRD before allogeneic BMT is still controversial. Method Multicentric study where we have studied correlative AML patients who went under an allo-HSCT in a situation of complete response, between 2012 and April'18. The MRD was analyzed by 8-coloured multiparametric flow cytometry, at least with 2 tubes per patient and 1,000,000 events per tube. We evaluated the prognostic value of the MRD before allo-HSCT. Results Between January'12 and April'18 we have gathered 90 allogeneic BMT in AML patients who were in CR, with a median age of 45 years old (17 - 66). The pre-HSCT situation was 1st complete remission (CR) in 75 patients and 2nd CR in 15. In 45 patients the conditioning regimen was myeoablative. In the group of patients (67) where we could know the risk group at diagnosis, the distribution was: low risk 18%, intermediate risk 59.7% and high risk 22.4%. The 46.7% of the donors were not related. In the last follow-up after allo-HSCT 24 patients have suffered a relapse (26.7%) and 41 (45.5%) have died (17 cases of mortality related to the transplant and 24 not related). In the global analysis the median follow-up of the overall survival (OS) was 37.5 months. Among the 90 patients, MRD was valuable in 86. Ten of 59 patients (16.9%) with negative MRD relapsed vs 12/27 (44.4%) with positive MRD, p= 0.016. If we consider only patients in 1st CR, 9/50 (18%) patients with negative MRD relapsed vs 10/22 (45.5%) with positive MRD, p= 0.02. This statistically significant difference does not exist if we consider only patients in 2nd CR. The median follow-up of OS and event free survival (EFS) was not reached in the negative MRD group and 571 days and 299 days in the positive MRD group. OS and EFS at 2 years after transplantation were 65% and 64% in the negative MRD group and 42% and 37% in the positive MRD group, p= 0.03 and p= 0.008 respectively (figure 1). Conclusions The detected MRD by 8-colour multiparametric flow cytometry previous an allo-HSCT in patients with AML in 1st CR is a prognostic factor in terms of relapse. Patients with a positive MRD before the allo-HSCT have a poorer OS and EFS than the patients with a negative MRD. Figure 1. Figure 1. Disclosures No relevant conflicts of interest to declare.

scholarly journals Prognostic value of minimal residual disease before allogeneic hematopoietic stem cell transplantation in patients with acute leukemia

2021 ◽  
Vol 66 (4) ◽  
pp. 539-555
Author(s):  
Z. V. Konova ◽  
E. N. Parovichnikova ◽  
I. V. Galtseva ◽  
M. Yu. Drokov ◽  
Yu. O. Davydova ◽  
...  
Keyword(s):  
Acute Leukemia ◽  
Minimal Residual Disease ◽  
Prognostic Value ◽  
Residual Disease ◽  
Disease Status ◽  
Long Term Results ◽  
Disease Relapse ◽  
Hematopoietic Stem ◽  
Post Transplant ◽  
Minimal Residual

Introduction. One of the main causes of treatment failure after allogeneic hematopoietic stem cells transplantation (alloHSCT) for acute leukemia (AL) is disease relapse. In recent years, multiparameter fl ow cytometry (MPC) has been widely used to detect minimal residual disease (MRD) because of its capacity to identify patients with a high risk of relapse due to availability and the ability to obtain results in a timely manner.Aim — to evaluate the prognostic value of MRD status before allo-HSCT and the effect of donor type and conditioning intensity on long-term results of allo-HSCT of MOB-positive patients.Patients and methods. The analysis included 107 patients with acute myeloid leukemia (AML) and 63 patients with acute lymphoblastic leukemia (ALL) who underwent allo-HSCT between September 2015 and June 2020. All patients were in complete morphological remission before allo-HSCT. At the time of allo-HSCT 91 patients with AML and 37 patients with ALL were in the first complete remission (CR), in their second and more than two CRs were 16 and 26 patients, respectively. The median follow-up was 18 (1.5–48) months for AML and 14 (1.8–60.1) months for ALL. Immunophenotypic study was performed before allo-HSCT. MRD was detected using a combination of the “different from normal” method and the search for cells with a leukemia-associated immunophenotype.Results. The disease status at the time of transplantation and the presence of MRD before allo-HSCT were independent factors infl uencing the probability of relapse (disease status: HR = 2.911, 95% CI: 1.328–6.379; MRD before allo-HSCT: HR = 7.667, 95% CI: 3.606–16.304) and post-transplant mortality (disease status: HR = 2.911, 95% CI: 1.328–6.379; MRD before allo-HSCT: HR = 7.667, 95% CI: 3.606–16.304). In univariate analysis, the relapse-free survival of MRD+ patients with AL in the first CR was significantly worse than in MRD– (AML: 23 % versus 57 %, p < 0.0001, ALL: 34 % versus 61.7 %, p = 0.0484), and the probability of relapse in MRD+ patients was significantly higher (AML: 75 % versus 12 %, p < 0.0001, ALL: 57 % versus 7 %, p = 0.0072). Pre-transplant MRD status was not prognostically significant for AL-patients in the second and third remission. The development of chronic GVHD reduces post-transplant mortality if it does not require systemic therapy with glucocorticosteroids (HR = 0.006, 95% CI: 0.008–0.446).Conclusion. Testing for MRD of patients with AL in the first CR before allo-HSCT is necessary for risk stratification and identification of patients who will need preventive post-transplant therapy in order to prevent disease relapse.

scholarly journals How I treat measurable (minimal) residual disease in acute leukemia after allogeneic hematopoietic cell transplantation

Blood ◽  
2020 ◽  
Vol 135 (19) ◽  
pp. 1639-1649 ◽  
Author(s):  
Alexandros Spyridonidis
Keyword(s):  
Acute Leukemia ◽  
Minimal Residual Disease ◽  
Cell Transplantation ◽  
Hematopoietic Cell Transplantation ◽  
Residual Disease ◽  
Hematopoietic Cell ◽  
Allogeneic Hematopoietic Cell Transplantation ◽  
Leukemia Relapse ◽  
Minimal Residual

Abstract Although allogeneic hematopoietic cell transplantation (allo-HCT) is currently the standard curative treatment of acute leukemia, relapse remains unacceptably high. Measurable (minimal) residual disease (MRD) after allo-HCT may be used as a predictor of impending relapse and should be part of routine follow-up for transplanted patients. Patients with MRD may respond to therapies aiming to unleash or enhance the graft-versus-leukemia effect. However, evidence-based recommendations on how to best implement MRD testing and MRD-directed therapy after allo-HCT are lacking. Here, I describe our institutional approach to MRD monitoring for preemptive MRD-triggered intervention, using patient scenarios to illustrate the discussion.

Monitoring Minimal Residual Disease in AML By Patient Specific Mutational Fingerprint Using Multiplex PCR and Deep Sequencing

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 1715-1715
Author(s):  
Christina Orsmark Pietras ◽  
Henrik Lilljebjörn ◽  
Vladimir Lazarevic ◽  
Marianne Rissler ◽  
Mats Ehinger ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Complete Remission ◽  
Multiplex Pcr ◽  
Residual Disease ◽  
Patient Specific ◽  
Mutation Pattern ◽  
Pcr Assays ◽  
Minimal Residual ◽  
Risk Of Relapse

Abstract Introduction: Acute myeloid leukemia (AML) is a heterogeneous disease characterized by clonal expansion of abnormal hematopoietic progenitor cells. With induction chemotherapy, patients attain a high rate of complete remission as measured by cytogenetic and flow cytometry markers; however, the majority eventually experience relapse. Accurate monitoring of minimal residual disease (MRD) can provide important information for relapse prediction, but current techniques rely on single somatic mutations or a small number flow cytometry markers. It was recently shown that subsets of leukemia-associated mutations can persist after treatment, even if standard clinical evaluation suggests complete remission. Such patients have an increased risk of relapse and reduced overall survival. It is however difficult to foresee which mutations at diagnosis that will persist and contribute to the leukemic relapse. To reliably monitor MRD status, a compelling strategy would be to ascertain as many mutations as possible. We here demonstrate how this can be achieved using an automated design of multiplex PCR primers followed by deep sequencing of the PCR products, enabling monitoring of MRD and mutation pattern based on each patients initial unique mutational fingerprint. Methods: We selected five patients with AML or high risk myelodysplastic syndrome (MDS) with whole exome sequencing (WES) data available from a diagnostic bone marrow or a peripheral blood sample together with a matched skin biopsy for identification of somatic variants. All five cases had material available from presentation, at least one follow up time point, and at relapse. All somatic coding mutations with a variant allele frequency (VAF) above 5% from the WES that passed the sequencing quality threshold were included, constituting the patients mutational fingerprint. The number of mutations ranged from 9 to 33 per patient. Individualized multiplex PCR assays (1-2 multiplex PCR assays/patient) were designed towards all fingerprint mutations using in-house software together with MPprimer. The multiplex PCRs were performed using Qiagen multiplex PCR kit (Qiagen). Each patient specific fingerprint analysis was performed on paired diagnosis, follow up and relapse samples. Sequencing libraries were generated using Nextera XT DNA library prep kit (Illumina) and sequencing was performed on a NextSeq500 (Illumina). Variant recalling was performed using freebayes and only variants with a VAF>5% and coverage above 100X in the diagnostic sample were considered successful MRD markers. Results: Automatic primer design was possible for 84 out of the total 88 mutations (95%). 75 of the targets (89%) were regarded successfully amplified in the multiplex PCR (sequencing coverage above 100X) and had a median coverage of 6566X. The error rate was estimated to around 1%. This multiplex PCR and sequencing approach allowed us to track each patient's unique mutation pattern in the follow up samples and at relapse. We could identify three patients in which all mutations were cleared in the follow up samples prior to relapse (Fig. 1a, b, c) and two patients in which not all mutations were cleared in the follow up samples (Fig. 1d, e). We could also identify which of the mutations at diagnosis that were present also at relapse (Fig. 1a-e). Hence, this approach is a relatively cost effective, fast and reliable assay for monitoring the disease-causing AML clone during a follow up. Conclusions: Traditional MRD monitoring by detection of single mutations or aberrant expression of flow cytometry markers is a proven and powerful method for identifying patients with a higher risk of relapse. However, a known problem with this approach is the risk that some markers are lost at relapse. We here describe a straight forward method allowing the diagnostic patient specific mutational fingerprint to be followed, which should serve as a more stable disease marker of the aberrant clone. In the five patients investigated, we could track mutations that were cleared, persisted despite clinical signs of remission, and mutations that were retained or lost at relapse. In a clinical setting, following an initial screen for somatic variants by WES, the individual multiplex PCR MRD assay could easily and at a relatively low cost be performed in any small NGS lab, thus allowing improved risk stratification and follow up of patents diagnosed with AML and other malignant hematologic disorders. Disclosures Fioretos: Cantargia: Equity Ownership.

Potential Predictive Patterns of Minimal Residual Disease Detected by Immunohistochemistry on Bone Marrow Biopsy Specimens During a Long-term Follow-up in Patients Treated With Cladribine for Hairy Cell Leukemia

2006 ◽  
Vol 130 (3) ◽  
pp. 374-377 ◽  
Author(s):  
Paulette Mhawech-Fauceglia ◽  
Martin Oberholzer ◽  
Senait Aschenafi ◽  
Audrey Baur ◽  
Michael Kurrer ◽  
...  
Keyword(s):  
Complete Remission ◽  
Minimal Residual Disease ◽  
Hairy Cell Leukemia ◽  
Residual Disease ◽  
Hairy Cell ◽  
Cell Leukemia ◽  
Biopsy Specimens ◽  
Patients At Risk ◽  
Minimal Residual

Abstract Context.—Minimal residual disease (MRD) in patients treated for hairy cell (HC) leukemia as assessed by immunohistochemistry has not been included routinely in evaluation of treatment results. Objective.—To assess the presence of persistent HCs after treatment, as detected by immunohistochemistry, and to evaluate the correlation between the level of MRD and clinical outcome. Design.—Percentages of DBA.44-positive HCs were assessed on 116 biopsy specimens from 17 patients. The patients had a median follow-up of 55.4 months. Results.—Minimal residual disease was seen in 3 patterns. Group 1 (7 patients) had MRD levels ranging from “rare scattered suspicious HCs” to less than 1%. The MRD levels were stable throughout follow-up, and all patients remained in complete remission. Group 2 (6 patients) had MRD levels ranging from 1% to 5%, and 3 patients were in complete remission at 77.9, 63.8, and 108.0 months. Another patient showed evidence of disease activity (partial remission) at 47.6 months. Two other patients relapsed at 12.3 months and at 25.7 months, respectively, with greater than 1% HCs. Group 3 (4 patients) had MRD levels greater than 5%. Three patients relapsed at 11.3, 12.1, and 29.6 months, respectively, with greater than 5% HCs. The fourth patient had MRD levels of 5% at 14.6 months and 2% at 20.0 months but was subsequently lost to follow-up. Conclusions.—Quantitative assessment of MRD may be of value in identifying patients at risk for relapse of hairy cell leukemia.

Prognostic Value of DNA Ploidy By Flow Cytometry for Pediatric B-Cell Acute Lymphoblastic Leukemia: A Peruvian Cohort Study

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 4-5
Author(s):  
Elizabeth Cervantes ◽  
Daniel J Enriquez ◽  
Judith Vidal ◽  
Rosario Retamozo ◽  
Arturo Zapata ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Clinical Trials ◽  
Acute Lymphoblastic Leukemia ◽  
Prognostic Value ◽  
Dna Ploidy ◽  
Residual Disease ◽  
Lymphoblastic Leukemia ◽  
Cell Acute Lymphoblastic Leukemia ◽  
Minimal Residual

Background: B-cell Acute Lymphoblastic Leukemia (B-ALL) represents an aggressive malignancy but highly curable in children. Currently, pediatric collaborative clinical trials have reported survival rates that exceed 90%, and DNA ploidy by flow cytometry (FC) has been pointed for risk stratification and prognosis in these clinical trials. However, its generalized use remains controversial as few studies reported no impact in real-world populations. We aimed to evaluate prognostic value of DNA ploidy measured by FC in a large cohort of Peruvian children with B-ALL. Methods: We evaluated prospectively DNA-ploidy by FC in bone marrow diagnostic samples from newly diagnosed children (&lt;15 years) with B-ALL treated at Instituto Nacional de Enfermedades Neoplasicas (Lima-Peru) between 2017-2019. DNA-ploidy was evaluated using Propidium Iodide and calculated as the mean ratio between fluorescence of pathologic B blasts and normal marrow cells. Ploidy categories were established based on previous reports of DNA-index(DI): Diploid + Low-Hyperdiploidy (DLH; DI: 0.95 - 1.15), hypo-diploid (HD; DI&lt;0.95) and High-hyperdiploidy (HH; DI&gt;1.15), and recalculated using maximally selected rank statistics. Samples were analyzed in a FacsCanto II flow cytometer (BD) and Infinicyt software (Cytognos). All patients received BFM-2009 protocol and had minimal residual disease evaluation at the end of IA and IB induction. Minimal residual disease (MRD) was evaluated with FC using a detection threshold of 0.0025% and considering positive ≥0.01%. Survival curves (event-free and overall survival) were estimated using the Kaplan-Meier method and compared with the Log-rank test. Results: A total of 192 children were included (2 HD, 141 DLH and 49 HH cases according to DNA ploidy by FC). Clinical characteristics and outcomes are shown in Table 1. Median age at diagnosis was 5 years (Range:1-14), 10 years for HD, 6 and 3 years for DLH and HH, respectively (p=0.002). F/M ratio was 1:1.3 for all cases, but 1:2 in HH group. Most karyotypes (62%) had unsatisfactory or poor-quality result, 29% were considered normal, and only 9 hyperdiploidy and 2 hypodiploidy cases were detected by conventional karyotyping. Regarding genetics, 21 TEL/AML, 19 E2A/PBX1 and 9 BCR/ABL cases were detected by multiplex-PCR and most balanced alterations had DLH subtype and only one HD case had TEL/AML. MRD positivity after Induction IA was 35% without difference between groups (50% HD, 36% DLH and 31% HH, p=0.77), however after Induction IB, MRD was positive in 50% of HD, 12% of DLH and 5% of HH (p=0.048). At eight-teen months of follow-up, one relapse was seen in HD cases, and 11% DLH and 10% in HH. Median EFS and OS was not reached, however one-year EFS and OS were 86% for both without significant differences between groups. Multivariate analysis showed that MRD positivity remains as the principal independent prognostic factor and ploidy by DNA did not show any impact in terms of MRD, EFS and OS. Conclusion: High-Hyperdiploidy by DNA ploidy was associated to better MRD negativity rate after induction IB but without impact in short-term EFS and OS. DNA ploidy did not represent a prognostic factor in our study cohort, however long-term follow-up is warranted. Additionally, a better genetic risk stratification is necessary to improve outcomes in Latino high-risk population. Disclosures No relevant conflicts of interest to declare.

Minimal Residual Disease Quantification in Ovarian Tissue Collected in Patients in Complete Remission of Acute Leukemia

Blood ◽  
2020 ◽  
Author(s):  
Florian Chevillon ◽  
Emmanuelle Clappier ◽  
Chloe Arfeuille ◽  
Jean-Michel Cayuela ◽  
Jean-Hugues Dalle ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Complete Remission ◽  
Acute Leukemia ◽  
Minimal Residual Disease ◽  
Residual Disease ◽  
Ovarian Tissue ◽  
Ovarian Tissue Cryopreservation ◽  
Hematopoietic Stem ◽  
Leukemic Infiltration ◽  
Minimal Residual

Ovarian tissue cryopreservation (OTC) is offered to women treated for acute leukemia to preserve their fertility before hematopoietic stem cell transplantation. The risk of leukemic infiltration in ovarian samples harvested before administration of chemotherapy limits ovarian tissue transplantations. We assessed the minimal residual disease (MRD) by sensitive quantitative polymerase chain reaction in cryopreserved ovarian cortex and medulla samples harvested from 30 patients in complete remission of acute leukemia, including 60 % with negative bone marrow MRD at the time of OTC. Ovarian MRD was undetectable in 21 patients (70%), detectable below 10-4 in 8 patients (27%) and between 10-3 and 10-4 in 1 patient (3%). Twenty patients (67%) had concordant MRD between bone marrow and ovarian samples. Interestingly 4 patients had positive MRD in ovarian samples while undetectable in bone marrow. Our results underline the importance of reaching the best control of the disease with undetectable or low MRD levels before OTC to minimize the risk of ovarian leukemic infiltration. The discordant results between ovarian samples and bone marrow require to test the more ovarian samples available before considering ovarian tissue transplantation.

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