Mimics and artefacts of measurable residual disease in a highly sensitive multicolour flow cytometry assay for B‐lymphoblastic leukaemia/lymphoma: critical consideration for analysis of measurable residual disease

Author(s):  
Gaurav Chatterjee ◽  
Harshini Sriram ◽  
Sitaram Ghogale ◽  
Nilesh Deshpande ◽  
Twinkle Khanka ◽  
...  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kentaro Narita ◽  
Daisuke Miura ◽  
Takafumi Tsushima ◽  
Toshiki Terao ◽  
Ayumi Kuzume ◽  
...  

AbstractStringent complete response (sCR) is defined as a deeper response than complete response (CR) in multiple myeloma. Whether achieving sCR correlates with better survival remains controversial. We evaluated the outcomes in patients with intact immunoglobulin multiple myeloma (IIMM) and light chain multiple myeloma (LCMM) who achieved a very good partial response (VGPR) or better. Multicolour flow cytometry was used to assess the depth of response. LCMM patients with sCR had significantly lower measurable residual disease (MRD) levels than those with CR (median MRD: 7.9 × 10–4 vs. 5.6 × 10–5, P < 0.01). Nonetheless, no significant difference was observed in MRD levels across the responses in groups of patients with IIMM (VGPR vs. CR: 3.5 × 10–4 vs. 7.0 × 10–5, P = 0.07; CR vs. sCR: 7.0 × 10–5 vs. 5.4 × 10–5, P = 0.81. In accordance with MRD levels, the median overall survival of patients with sCR was significantly longer (sCR, CR, VGPR; not reached, 41 months, and 58 months, respectively; VGPR vs. CR, P = 0.83; CR vs. sCR, P = 0.04) in LCMM, but not in IIMM (sCR, CR, VGPR; not reached, 41 months, and not reached, respectively; VGPR vs. CR, P = 0.59; CR vs. sCR; P = 0.10). Our results show that sCR represents a deeper response that correlates with longer survival in patients with LCMM, but not IIMM.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 5083-5083
Author(s):  
Raffaele Palmieri ◽  
Luca Maurillo ◽  
Alfonso Piciocchi ◽  
Maria Ilaria Del Principe ◽  
Valentina Arena ◽  
...  

Background: Mutations of the gene encoding Fms Related Tyrosine Kinase 3 (FLT3), at the juxta-membrane level (ITD), represent the most common lesions found in Acute Myeloid Leukemia (AML), identifying a subgroup of patients (pts) with unfavorable prognosis. FLT3-ITD mutations are considered an unreliable tool for measurable residual disease (MRD) monitoring, due to their intraclonal heterogeneity and instability during the course of disease. Instead, multiparametric flow cytometry (MFC) may represent an alternative to monitor MRD in this molecular subset. In fact, through the recognition and monitoring of leukemia associated immunophenotypes, MFC is applicable to > 90% of AML patients with a sensitivity of 10-4. Aims: The aim of our study was to investigate the reliability of MFC in MRD assessment of 72 FLT3-ITD positive pts whose treatment allocation was prospectively decided according to the genetic/cytogenetic profile at diagnosis and post consolidation MRD. FLT3-ITD pts were to receive, after induction and consolidation, allogeneic stem cell transplant (ASCT), whatever the source of stem cells. In this subgroup analysis, we investigated if FLT3-ITD mutated pts have a different propensity to achieve high quality (e.g. MRD negative) complete remission as compared to FLT3 wildtype ones. Furthermore, we seek for a correlation between different levels of MRD and overall (OS) and disease-free survival (DFS). Methods: We included in the analysis 72 pts with de novo AML carrying FLT3-ITD mutations whose MRD assessment at the post-consolidation timepoint was available. Pts were defined as MRD-negative, when obtaining a residual leukemic cells count below the threshold of 3.5x10-4 (0.035%). MRD positive pts (with MRD ≥ 3.5x10-4 RLC) were stratified into 3 classes according to the levels of MRD (0.035%-0.1%; >0.1%-1%; >1%). We compared the MRD status and clinical outcome with a matched group of FLT3 wildtype AML (n = 203) treated in the same protocol. Results: Overall median age was 49 (range 18-60.9). The 2 cohorts were balanced in terms of age and sex distribution. In the FLT3-ITD group, 80/126 (64%) cases carried a concomitant NPM1 mutation vs 107/374 (28.6%) of FLT3 wildtype ones (p <0.001). Furthermore, FLT3 mutated pts had a median WBC count of 35x109/L vs 9.5x109/L of those FLT3 wildtype (p < 0.001). MRD determination after consolidation cycle was available in 72/126 FLT3-ITD pts (57%) and in 203/374 FLT3 wildtypeones (54.3%), respectively. After having received induction and consolidation course, 47/72 FLT3-ITD pts (65,2%) were submitted to allogenic stem cells transplantation (ASCT). At the post-consolidation time-point, MRD negativity rate was significantly lower in FTL3-ITD pts (27/72, 37.5%) as compared to those FLT3 wildtype (94/203, 46.3%). Furthermore, 38/72 (52.8%) and 10/72 (13.9%) FLT3-ITD pts had a level of MRD > 0.1% and > 1%, respectively as compared to 65/203 (33.0%) and 15/203 (7.4%) of FLT3 wildtypeones, respectively (p=0.017). When considering the different MRD stratification levels of FLT3-ITD pts, OS probability at 24 months was 57.2% (27 pts), 71.4% (7 pts), 53.6% (28 pts) and 20% (10 pts), for the MRD categories <0.035%, 0.035%-0.1%, >0.1%-1%, >1%, respectively (p=0.028). DFS probability at 24 months was 53.8% (27 pts), 71.4% (7 pts), 34.9% (27 pts) and 20% (10 pts), for the MRD categories <0.035%, 0.035%-0.1%, >0.1%-1%, >1%, respectively (p=0.038). Summary/Conclusion: We demonstrated that MRD determination by MFC is a reliable tool to assess remission quality and prognosis in FLT-ITD positive patients. This subpopulation shows a lower propensity to obtain a MRD negative CR, with the majority of pts maintaining an amount of MRD > 0.1% after standard treatment. Even though most of these pts were addressed to ASCT, post-consolidation MRD maintained its negative impact on OS and DFS, particularly for those pts with MRD >1%. In the attempt to improve the quality of response, prevent leukemia recurrence and pursue a durable remission, delivery of FLT3 inhibitors as a maintenance after transplant may represent a promising option. Disclosures Venditti: Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Abbvie: Consultancy; Astellas: Membership on an entity's Board of Directors or advisory committees; Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees; Daiichi-Sankyo: Consultancy, Membership on an entity's Board of Directors or advisory committees. Buccisano:Janssen: Membership on an entity's Board of Directors or advisory committees; Astellas: Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau.


Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 1688-1688
Author(s):  
Soraya Wuilleme ◽  
Nelly Robillard ◽  
Steven Richebourg ◽  
Marion Eveillard ◽  
Laurence Lodé ◽  
...  

Abstract Abstract 1688 The eradication of minimal residual disease (MRD) in myeloma predicts for improved outcome. A number of different approaches to myeloma MRD detection are available; these vary widely in sensitivity and cost. Flow cytometric assessment of MRD may be preferable in practice because of lower cost and easier feasibility. Myeloma MRD flow cytometry requires at least three markers for plasma cell identification (CD38, CD138 and CD45) and combination of several additional markers to detect phenotypic abnormality including CD19, CD20, CD27, CD28, CD45, CD56 and CD117. Also, assessment of immunoglobulin light-chain restriction (cytoplasmic K and L) combined with myeloma-associated phenotypic plasma cell abnormalities, is very important. Four-tube four-colour flow cytometry combine markers CD38/CD138/CD45 with markers for plasma cell phenotypic abnormalities and clonality. Six –colour flow cytometry combines the same markers (markers for plasma cell identification) plus clonality markers; it potentially increases the sensitivity of the method through coincident multiparameter analysis. However, the single-tube six-colour flow cytometry, proposed by others studies, excludes the myeloma-associated phenotypic plasma cell abnormalities and consequently decreases specificity of the assay. We propose a new single-tube seven-colour flow cytometry, including plasma cell identification antigens, clonality markers and myeloma-associated phenotypic plasma cell abnormalities markers. In this new method, PCs are stained with antibodies: (i) CD38, CD138, CD45 used for identified plasma cells and percentage plasma cells to total leucocytes. (ii) CD19 and CD56+CD28 used to identify normal and abnormal plasma cells; and (iii) cy-IgK and cy-IgL, for confirm the plasma cells clonality. We analysed normal bone marrow provided from healthy individuals. Our results showed a presence myeloma-associated phenotypic plasma cell abnormalities at low levels in healthy individual. The monotypy studies confirm polyclonality of this normal plasma cells. Then we compared MRD assessement with single-six colour flow cytometry assay (plasma cells markers, clonality markers and exluding myeloma-associated phenotypic markers) and seven-colour flow cytometry assay (including myeloma-associated phenotypic markers). Six –colour flow cytometry has a better sensitivity and showed efficacy for quantification MRD in myeloma patients. However, the single-tube six-colour flow cytometry excluded the myeloma-associated phenotypic plasma cell abnormalities and in some cases the seven-colour flow cytometry will be more informative because it detected myeloma-asociated phenotypic marquers combined with clonality marquers. Finally, the single-tube seven colour flow cytometry assay provides reduction in antibody cost and increases sensitivity and specificity of the method through coincident multiparameter analysis. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 1378-1378
Author(s):  
Roger Belizaire ◽  
Olga Pozdnyakova ◽  
Daniel J. DeAngelo ◽  
Betty Li ◽  
Karry Charest ◽  
...  

Abstract Flow cytometry for detection of minimal residual disease (MRD) in acute lymphoblastic leukemia (ALL) has been widely used in pediatric patients to quantify therapeutic response and to assess the risk of relapse. Flow cytometry for MRD provides roughly the same level of sensitivity (0.01%) as molecular methods but at lower cost and with faster turnaround time. MRD assessment in ALL currently requires an evaluation of 20 or more parameters divided among multiple tubes. In part due to the assessment complexity, the use of flow cytometry for MRD detection in adult ALL patients has been relatively limited. We developed a 6-color, single-tube, flow cytometry assay to detect MRD in bone marrow (BM) aspirate specimens from adult ALL patients. The 73 patients included 52 patients with B-ALL (71%), 19 patients with T-ALL (26%) and 2 patients with T/myeloid leukemia (3%) and were treated with one of several standard chemotherapeutic regimens or targeted therapies. Patients were tested for MRD by flow cytometry after induction or re-induction therapy and serially thereafter. The 6-marker MRD panel was customized for each patient based on the 18-20-marker diagnostic immunophenotype. Sixty-three percent of B-ALL patients (n=33) had lymphoblasts with an aberrant immunophenotype; expression of a myeloid marker (e.g., CD13, CD15 or CD33) was the most common aberrancy. The remaining 37% of B-ALL patients (n=19) had disease with a hematogone immunophenotype, which comprised surface expression of CD10, CD19, CD20, CD34, CD38 and CD45; in the majority of these cases, leukemic cells were distinguishable from normal hematogones based on the intensity of surface marker expression. Forty-seven percent of T-ALL patients (n=9) had an aberrant immunophenotype, most often characterized by CD33 expression. One-hundred forty-six consecutive specimens analyzed for MRD by flow cytometry were classified as positive (23%), negative (72%) or uncertain (5%). Of the 34 samples classified as positive, 14 (41%) showed morphologic (i.e., BM aspirate or biopsy) evidence of disease; nineteen (65%) samples did not show morphologic evidence of disease and 1 sample did not have a concurrent morphologic assessment. Of the 105 samples classified as negative by flow cytometry, 103 (98%) were also negative by morphology and 1 sample did not have a concurrent morphologic assessment. One sample that was negative by flow cytometry had morphologic evidence of disease in the biopsy (10-20% blasts) but not the aspirate, suggesting that aspirate sampling artifact was responsible for the discrepancy. None of the 7 samples classified as uncertain by flow cytometry had morphologic evidence of disease; five out of 7 uncertain classifications were in B-ALL patients with hematogone immunophenotypes. Overall, MRD flow cytometry showed 86% concordance with the results of morphologic assessment. We evaluated outcomes in all patients with negative morphologic results and any positive MRD flow cytometry result(s). Of the 73 patients in this study, 61 had morphology-negative results that were either MRD-negative (n=45) or MRD-positive (n=16). Patients in this group were at various points of treatment post-induction or re-induction. Four out of 45 patients (9%) with MRD-negative results relapsed during a median follow-up period of 22 months, and 8 out of 16 patients (50%) with an MRD-positive result relapsed during a median follow-up period of 15 months (odds ratio for relapse 10.3, 95% confidence interval 2.5-42.4, P=0.001). In addition, relapse-related and overall mortality (Figure 1) were higher in patients with MRD-positive results (P=0.0023 and P=0.0016, respectively, by the log-rank test). In summary, we present a simplified, single-tube, flow cytometry assay that can be used to detect MRD in adult ALL at relatively low cost with rapid turnaround time; our approach was applicable to cases with either hematogone or aberrant immunophenotype, yielding a definitive result in 95% of cases. Notably, the presence of MRD was associated with relapse and mortality, suggesting that our method of MRD assessment could be used to guide treatment of adult ALL. Further analysis of the correlations between MRD results, clinical management and patient outcomes is ongoing. Disclosures: No relevant conflicts of interest to declare.


2021 ◽  
Vol 11 ◽  
Author(s):  
Fu-Jia Liu ◽  
Wen-Yan Cheng ◽  
Xiao-Jing Lin ◽  
Shi-Yang Wang ◽  
Tian-Yi Jiang ◽  
...  

The clinically ideal time point and optimal approach for the assessment of measurable residual disease (MRD) in patients with acute myeloid leukemia (AML) are still inconclusive. We investigated the clinical value of multiparameter flow cytometry-based MRD (MFC MRD) after induction (n = 492) and two cycles of consolidation (n = 421). The latter time point was proved as a superior indicator with independent prognostic significance for both relapse-free survival (RFS, HR = 3.635, 95% CI: 2.433–5.431, P &lt;0.001) and overall survival (OS: HR = 3.511, 95% CI: 2.191–5.626, P &lt;0.001). Furthermore, several representative molecular MRD markers were compared with the MFC MRD. Both approaches can establish prognostic value in patients with NPM1 mutations, and FLT3, C-KIT, or N-RAS mutations involved in kinase-related signaling pathways, while the combination of both techniques further refined the risk stratification. The detection of RUNX1–RUNX1T1 fusion transcripts achieved a considerable net reclassification improvement in predicting the prognosis. Conversely, for patients with biallelic CEBPA or DNMT3A mutations, only the MFC method was recommended due to the poor prognostic discriminability in tracking mutant transcripts. In conclusion, this study demonstrated that the MFC MRD after two consolidation cycles independently predicted clinical outcomes, and the integration of MFC and molecular MRD should depend on different types of AML-related genetic lesions.


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