scholarly journals Detection of terminal deoxynucleotidyl transferase (TdT) by flow cytometry in leukemic disorders.

1989 ◽  
Vol 37 (4) ◽  
pp. 509-513 ◽  
Author(s):  
R H Bardales ◽  
A Carrato ◽  
M Fleischer ◽  
M K Schwartz ◽  
B Koziner
Keyword(s):  
Flow Cytometry ◽  
Fluorescence Microscopy ◽  
Myeloid Leukemia ◽  
De Novo ◽  
Lymphoblastic Leukemia ◽  
Biochemical Assay ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Large Numbers ◽  
A New Technique ◽  
T Lymphoblastic Lymphoma

We applied a new technique to the detection of intracellular TdT in 26 leukemic patients, including 16 non-T acute lymphoblastic leukemia (ALL), four T-ALL, one T-lymphoblastic lymphoma in leukemia phase, one undifferentiated leukemia, one de novo lymphoblastic phase of chronic myeloid leukemia, and three acute monocytic leukemias (AMOL). Mononuclear cell suspensions were incubated in saponin to permeabilize the cell membrane. The cells were then stained by indirect immunofluorescence (IF) using anti-human TdT monoclonal antibodies and were analyzed by flow cytometry (FCM). The TdT results were compared with those obtained by biochemical TdT assay (26 cases), immunoperoxidase determination (PAP) (12 cases), and fluorescence microscopy (seven cases). The results obtained by PAP and fluorescence microscopy were 100% concordant with those obtained by FCM and biochemical assay. TdT determination by FCM allows the analysis of large numbers of cells in a fast, objective, and reliable manner, as compared with biochemical assay, PAP, and fluorescence microscopy determinations.

scholarly journals HRX involvement in de novo and secondary leukemias with diverse chromosome 11q23 abnormalities [see comments]

Blood ◽  
1993 ◽  
Vol 81 (12) ◽  
pp. 3197-3203 ◽  
Author(s):  
SP Hunger ◽  
DC Tkachuk ◽  
MD Amylon ◽  
MP Link ◽  
AJ Carroll ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Topoisomerase Ii ◽  
De Novo ◽  
Lymphoblastic Leukemia ◽  
Myelogenous Leukemia ◽  
Chromosome Band ◽  
11Q23 Abnormalities ◽  
Acute Myeloid ◽  
Secondary Leukemias

Abstract Chromosome band 11q23 is a site of recurrent translocations and interstitial deletions in human leukemias. Recent studies have shown that the 11q23 gene HRX is fused to heterologous genes from chromosomes 4 or 19 after t(4;11)(q21;q23) and t(11;19)(q23;p13) translocations to create fusion genes encoding proteins with structural features of chimeric transcription factors. In this report, we show structural alterations of HRX by conventional Southern blot analyses in 26 of 27 de novo leukemias with cytogenetically diverse 11q23 abnormalities. The sole case that lacked HRX rearrangements was a t(11;17)-acute myeloid leukemia with French-American-British M3-like morphology. We also analyzed 10 secondary leukemias that arose after therapy with topoisomerase II inhibitors and found HRX rearrangements in 7 of 7 with 11q23 translocations, and in 2 of 2 with unsuccessful karyotypes. In total, we observed HRX rearrangements in 35 leukemias involving at least nine distinct donor loci (1q32, 4q21, 6q27, 7p15, 9p21–24, 15q15, 16p13, and two 19p13 sites). All breakpoints localized to an 8-kb region that encompassed exons 5–11 of HRX, suggesting that fusion proteins containing similar portions of HRX may be consistently created in leukemias with 11q23 abnormalities. We conclude that alteration of HRX is a recurrent pathogenetic event in leukemias with 11q23 aberrations involving many potential partners in a variety of settings including acute myeloid leukemia, acute lymphoblastic leukemia, chronic myelogenous leukemia in blast crisis, and topoisomerase II inhibitor- induced secondary leukemias of both the myeloid and lymphoid lineages.

Clinical relevance of P-glycoprotein expression in de novo acute myeloid leukemia

Blood ◽  
1996 ◽  
Vol 87 (5) ◽  
pp. 1997-2004 ◽  
Author(s):  
G Del Poeta ◽  
R Stasi ◽  
G Aronica ◽  
A Venditti ◽  
MC Cox ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
De Novo ◽  
Survival Rates ◽  
Disease Free Survival ◽  
Normal Karyotype ◽  
Free Survival ◽  
Negative Phenotype ◽  
Acute Myeloid

Abstract Cytofluorimetric detection of the multidrug resistance (MDR)-associated membrane protein (P-170) was performed at the time of diagnosis in 158 patients with acute myeloid leukemia using the C219 monoclonal antibody (MoAb). In 108 of these cases the JSB1 MoAb was also tested. An improved histogram subtraction analysis, based on curve fitting and statistical test was applied to distinguish antigen-positive from antigen-negative cells. A marker was considered positive when more than 20% of the cells were stained. At onset, P-170 was detected in 43% of cases with C219 and in 73% of cases with JSB1. There was a strict correlation between C219 and JSB1 positivity, as all C219+ cases were also positive for JSB1 MoAb (P < .001). No relationship was found between sex, age, organomegaly, and MDR phenotype. Significant correlation was found between CD7 and both C219 and JSB1 expression (P < .001 and .001, respectively). C219-negative phenotype was more often associated with a normal karyotype (24 of 55 with P = .030). Rhodamine 123 (Rh123) staining and flow cytometry analysis showed a significantly decreased mean fluorescence in 51 C219+ and 38 JSB1+ patients compared to 42 MDR negative ones (P < .001). The rate of first complete remission (CR) differed both between C219+ and C219- cases and between JSB+ and JSB- ones (30.9% v 71.1% and 35.4% v 93.1%, respectively, P < .001). Of the 21 C219+ patients who had yielded a first CR, 19 (90.4%) relapsed, compared with 28 of 64 (43.7%) C219- patients (P < .001). Of the 28 JSB1+ patients in first CR, 17 (60.7%) relapsed relative to 8 (29.6%) of 27 JSBI- ones (P = .021). A higher rate of relapses among MDR+ compared with MDR- patients was observed both for C219 and JSB1 MoAbs taken separately (C219 80% v 44%; JSB1 52% v 27%), with no relationship to age. The survival rates (Kaplan-Meyer method) were significantly shorter both in C219+ patients and in JSB1+ cases (P < .001). Disease-free survival curves followed this same trend. The combination (C219- JSB1+) identified a subset of patients with an intermediate outcome compared to C219 positive cases. The prognostic value of both markers (C219 and JSB1) was confirmed in multivariate analysis. These results suggest that the assessment of MDR phenotype by flow cytometry may be an important predictor of treatment outcome.

scholarly journals Marked Variability in Reported Minimal Residual Disease Lower Level of Detection of 4 Hematolymphoid Neoplasms: A Survey of Participants in the College of American Pathologists Flow Cytometry Proficiency Testing Program

2015 ◽  
Vol 139 (10) ◽  
pp. 1276-1280 ◽  
Author(s):  
Michael Keeney ◽  
Jaimie G. Halley ◽  
Daniel D. Rhoads ◽  
M. Qasim Ansari ◽  
Steven J. Kussick ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Chronic Lymphocytic Leukemia ◽  
Minimal Residual Disease ◽  
Plasma Cell ◽  
Myeloid Leukemia ◽  
Residual Disease ◽  
Lymphoblastic Leukemia ◽  
Lymphocytic Leukemia ◽  
Plasma Cell Myeloma ◽  
Minimal Residual

Context Flow cytometry is often applied to minimal residual disease (MRD) testing in hematolymphoid neoplasia. Because flow-based MRD tests are developed in the laboratory, testing methodologies and lower levels of detection (LODs) are laboratory dependent. Objectives To broadly survey flow cytometry laboratories about MRD testing in laboratories, if performed, including indications and reported LODs. Design Voluntary supplemental questions were sent to the 549 laboratories participating in the College of American Pathologists (CAP) FL3-A Survey (Flow Cytometry—Immunophenotypic Characterization of Leukemia/Lymphoma) in the spring of 2014. Results A total of 500 laboratories (91%) responded to the supplemental questions as part of the FL3-A Survey by April 2014; of those 500 laboratories, 167 (33%) currently perform MRD for lymphoblastic leukemia, 118 (24%) for myeloid leukemia, 99 (20%) for chronic lymphocytic leukemia, and 91 (18%) for plasma cell myeloma. Other indications include non-Hodgkin lymphoma, hairy cell leukemia, neuroblastoma, and myelodysplastic syndrome. Most responding laboratories that perform MRD for lymphoblastic leukemia reported an LOD of 0.01%. For myeloid leukemia, chronic lymphocytic leukemia, and plasma cell myeloma, most laboratories indicated an LOD of 0.1%. Less than 3% (15 of 500) of laboratories reported LODs of 0.001% for one or more MRD assays performed. Conclusions There is major heterogeneity in the reported LODs of MRD testing performed by laboratories subscribing to the CAP FL3-A Survey. To address that heterogeneity, changes to the Flow Cytometry Checklist for the CAP Laboratory Accreditation Program are suggested that will include new requirements that each laboratory (1) document how an MRD assay's LOD is measured, and (2) include the LOD or lower limit of enumeration for flow-based MRD assays in the final diagnostic report.

Assessment Of Human Equilibrative Nucleoside Transporter 1 (hENT1) – Expression By Flow Cytometry In Acute Myeloid Leukemia and Myelodysplastic Syndromes and Correlation To Clinical Outcome In Acute Myeloid Leukemia Patients Treated With Intensive Chemotherapy

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 2582-2582 ◽  
Author(s):  
Frauke Bellos ◽  
Bruce H. Davis ◽  
Naomi B. Culp ◽  
Birgitte Booij ◽  
Susanne Schnittger ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Myeloid Leukemia ◽  
De Novo ◽  
Molecular Genetic ◽  
Newly Diagnosed ◽  
Employment Equity ◽  
Equity Ownership ◽  
De Novo Aml ◽  
Very High ◽  
Acute Myeloid

Abstract Background Nucleoside analogs depend on cellular hENT1 expression for entry into cells and cytotoxic activity. Studies suggest low cellular hENT1 levels correlate with poor response to such chemotherapies in solid tumors, data on AML and MDS is scarce. Aim To examine hENT1 expression by multiparameter flow cytometry (MFC) in newly diagnosed AML and MDS and correlate results to morphologic, cytogenetic (CG) and molecular genetic (MG) findings. To examine hENT1 expression with respect to clinical outcome in AML patients (pts) treated with intensive cytarabine-based chemotherapy (CHT). Methods We studied pts with newly diagnosed AML (n=145) and MDS (n=96), 133/108 male/female, median age 67.3 (AML) and 73.3 years (MDS). CG was done in 130 AML and 86 MDS. Pts included 107 de novo AML, 9 t-AML, 29 s-AML; FAB: 9 M0, 27 M1, 50 M2, 9 M3, 21 M4, 8 M4eo, 7 M5, 14 not classified; by CG (MRC): 21 favorable, 75 intermediate, 34 adverse. 91 were de novo MDS, 5 t-MDS; 1 RARS, 17 RCMD-RS, 37 RCMD, 3 5q- syndrome, 3 RAEB-1, 5 RAEB-2, 1 CMML, 24 not classified; 2 IPSS-R very low, 55 IPSS-R low, 8 IPSS-R intermediate, 8 IPSS-R high, 13 IPSS-R very high. hENT1 expression was quantified by a novel four color intracellular staining assay using monoclonal antibodies against hENT1, CD45, CD64 and myeloperoxidase. Median fluorescence intensities (MFI) of hENT1 were determined in myeloid progenitors (MP), granulocytes (G) and monocytic cells (Mo) and correlated to hENT1 MFI in lymphocytes to derive hENT1 index (index). Results No correlation of index to age, gender, hemoglobin level or counts for blasts, WBC or platelets was detected. In AML, we generally saw higher index by trend in the more favorable prognostic subgroups. M3/t(15;17)/PML-RARA+ displayed higher index in MP than non-M3 AML (4.24 vs 2.56, p<0.001). G index was lower in M0 (3.01) vs M1, M2, M4 and M4eo (5.66, 4.34, 5.35, 4.77; p=0.01, 0.028, 0.004, 0.043, respectively) and in M2 compared to M1 and M4 (4.34. vs 5.66 and 5.35, p=0.01 and 0.033, respectively). M2 showed lower MP index than M5 (2.42 vs 2.99, p=0.016). Considering CG, index in MP was higher in favorable vs intermediate and adverse pts (3.05 vs 2.58 and 2.53, p=0.034 and 0.023, respectively), Mo index was higher ín favorable vs adverse pts (3.17 vs 2.71, p=0.044). By MG, higher index in Mo and G was observed in RUNX1-RUNX1T1+ AML (4/83, 4.32 vs 3.04, p=0.01; 8.16 vs 4.60, p=0.002, respectively). Higher index for MP was found in FLT3-ITD mutated (mut) (18/111; 3.19 vs 2.62, p=0.012), CEPBA mut (4/26, 3.15 vs 2.35, p=0.004) and for Mo in NPM1 mut AML (23/104; 3.72 vs 2.84, p=0.02), whereas lower index for MP was found in RUNX1mut pts (13/65; 2.17 vs 2.59, p=0.031). De novo AML displayed higher MP index than s-AML (2.7 vs 2.28, p=0.008). Using lowest quartile of index for MP (2.1185) as cut-off, AML pts in the MRC intermediate group treated with CHT (n=38) had inferior OS if MP index was below vs above this cut-off (OS at 6 months 63% vs. 95%, p=0.017, median follow up 4.6 months). MDS showed lower Mo and MP index than AML (2.68 vs 2.96, p=0.021, 1.84 vs 2.65, p<0.001, respectively). By IPSS-R, significance was reached for higher index in Mo and MP in very low risk compared to low risk pts (3.39 vs 2.54, p=0.013 and 4.07 vs 1.78, p<0.001, respectively), MP in very low compared to intermediate and high risk pts (4.07 vs 1.95, p=0.004; 4.07 vs 1.76, p=0.002), and MP and G in very low vs very high risk pts (4.07 vs 1.71, p=0.005; 5.86 vs 3.85, p=0.001, respectively). IPSS-R intermediate vs poor and very poor showed lower G index (5.47 vs 3.59, p=0.018 and vs 3.85, p=0.034 respectively). Conclusion AML with genetic and molecular genetic good risk profile had higher hENT1 expression in MP, G and Mo, suggesting a causal mechanism for better response to CHT and better outcome. Consequently, AML with poor risk molecular genetics (RUNX1 mut) showed lower levels of hENT1 in MP. The detection of higher levels in FLT3-ITD mut pts is in line with reportedly good response to CHT, overall worse outcome being mostly due to early relapses. Strikingly, we saw differences in outcome in pts treated with CHT according to hENT1 expression with shorter OS in pts with low index for MP. Higher index in de novo AML than s-AML and MDS may be causal for better response to nucleoside-based CHT in de novo AML. Data for MDS may be interpreted accordingly, lower risk cases showing higher index in MP, G and Mo. Further analyses are needed to explore hENT1 expression in AML and MDS more comprehensively. Disclosures: Bellos: MLL Munich Leukemia Laboratory: Employment. Davis:Trillium Diagnostics, LLC: Equity Ownership. Culp:Trillium Diagnostics, LLC: Equity Ownership. Schnittger:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Kern:MLL Munich Leukemia Laboratory: Employment, Equity Ownership.

Minimal Residual Disease Monitoring in Childhood Precursor B Lymphoblastic Leukemia with t(12;21)(p13;q22); ETV6-RUNX1: A Comparison Between Quantitative RT-PCR and Flow Cytometry

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 3774-3774
Author(s):  
Sofie J Alm ◽  
Charlotte Engvall ◽  
Julia Asp ◽  
Lars Palmqvist ◽  
Jonas Abrahamsson ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Minimal Residual Disease ◽  
Residual Disease ◽  
Lymphoblastic Leukemia ◽  
Fusion Transcript ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Time Points ◽  
Qrt Pcr ◽  
Minimal Residual

Abstract The translocation t(12;21)(p13;q22) resulting in the fusion gene ETV6-RUNX1, is the most frequent gene fusion in childhood precursor B lymphoblastic leukemia (pre-B ALL), affecting about one in four children with pre-B ALL. In the NOPHO ALL-2008 treatment protocol, treatment assignment in pre-B ALL is based on clinical parameters, genetic aberrations, and results from analysis of minimal residual disease (MRD) at day 29 and 79 during treatment (where MRD >0.1% leads to upgrading of treatment). For pre-B ALL, in this protocol MRD analysis is performed using flow cytometry as the method of choice. In this study, we also analyzed MRD in t(12;21)(p13;q22) cases with quantitative reverse transcription-polymerase chain reaction (qRT-PCR) for the fusion transcript ETV6-RUNX1 in parallel with routine MRD analysis with flow cytometry, to determine if qRT-PCR of the ETV6-RUNX1 fusion transcript would be a reliable alternative to FACS. Bone marrow samples were collected at diagnosis and at day 15, 29 and 79 during treatment from 31 children treated according to the NOPHO ALL-2000 (n = 3) and NOPHO ALL-2008 (n = 28) protocols in Gothenburg, Sweden, between 2006 and 2013. Samples were analyzed in parallel with qRT-PCR for ETV6-RUNX1 fusion transcript and with FACS. For qRT-PCR, mRNA was isolated, cDNA synthesized, and qRT-PCR performed with GUSB as reference gene. MRD-qRT-PCR was defined as the ETV6-RUNX1/GUSB ratio at the follow-up time point (day 15/29/79) divided with the ETV6-RUNX1/GUSB ratio at diagnosis (%). MRD analysis with FACS was performed, after lysis of erythrocytes, using antibodies against CD10, CD19, CD20, CD22, CD34, CD38, CD45, CD58, CD66c, CD123, and terminal deoxynucleotidyl transferase, and when applicable also CD13 and CD33. Results of MRD-FACS were expressed as % of all cells. In total, 83 samples were analyzed with both methods in parallel; 31 from day 15 in treatment, 28 from day 29, and 24 from day 79. Overall, MRD-qRT-PCR showed good correlation with MRD-FACS. In total, 31 samples were positive with qRT-PCR and 24 with FACS, with concordant results (positive with both methods or negative with both methods) in 89% of samples, when the limit of decision (positive/negative MRD) was set to 0.1%. The concordance was especially high at the treatment stratifying time points, i.e. day 29 and 79; 89% and 100%, respectively. No samples at these time points were positive with FACS but negative with qRT-PCR. During the follow-up period (6-81 months), one patient relapsed (with negative MRD with both methods at stratifying time points), and two succumbed from therapy-related causes. Our results show that there is a significant relationship between the results of MRD analysis using FACS and MRD analysis using qRT-PCR of ETV6-RUNX1 fusion transcript. The high concordance between the methods indicates that negative MRD using qRT-PCR is as reliable as negative MRD using FACS, and that qRT-PCR could therefore be an alternative to FACS in cases where FACS is not achievable. In comparison to quantitative PCR of TCR/Ig gene rearrangements, which is the current backup MRD method for cases with pre-B ALL in NOPHO ALL-2008, qRT-PCR of ETV6-RUNX1 is much less time and labor consuming, making it appealing in a clinical laboratory setting. Disclosures No relevant conflicts of interest to declare.

scholarly journals Characterization of flow cytometric immuno-phenotyping of acute myeloid leukemia with minimal differentiation and acute T-cell lymphoblastic leukemia: A retrospective cross-sectional study

F1000Research ◽  
2020 ◽  
Vol 9 ◽  
pp. 1170
Author(s):  
Enass Abdul Kareem Dagher Al-Saadi ◽  
Marwa Ali Abdulnabi ◽  
Faris Hanoon Jaafar
Keyword(s):  
Flow Cytometry ◽  
Acute Myeloid Leukemia ◽  
T Cell ◽  
Myeloid Leukemia ◽  
Lymphoblastic Leukemia ◽  
Antigen Expression ◽  
Cross Sectional Study ◽  
Sectional Study ◽  
Cross Sectional ◽  
Acute Myeloid

Background: Acute leukemias (ALs) are a heterogeneous group of malignancies with various clinical, morphological, immunophenotypic, and molecular characteristics. Distinguishing between lymphoid and myeloid leukemia is often performed by flow cytometry. This study aimed to evaluate the immunophenotypic characterization and expression of immuno-markers in both acute myeloid leukemia (AML-M0) and acute T-cell lymphoblastic leukemia (T-ALL). Methods: A retrospective cross-sectional study was conducted in the Pathology Department/Teaching Laboratories/Medical City/Iraq and included all patients newly diagnosed with AL from 5 January to 10 December 2018. Immunophenotypic analysis was performed on bone marrow samples, freshly collected in EDTA tubes. Flow cytometry (Canto-2 BD) was used, with laser excitation of blue and red wavelengths. A panel of monoclonal antibodies (MoAbs) was used for diagnosis, using a SSC/CD45 gating strategy. Results: The study showed 41.6% of AML-M0 patients had no aberrant antigen expression, while 33.3%, 16.6%,  8.3%, and 8.3% had aberrant CD7, CD56, CD2, and CD19, respectively. In 16.6% of AML-M0 cases more than one aberrant antigen was expressed. With regard to T-ALL, 7.0% were pro-T type, 58.0% were pre-T, 13.0% were cortical, and 22.0% were mature-T type. In 55.5% of patients with T-ALL there was no aberrant antigen expression. Conclusion: We concluded that most patients with AML-M0 have no aberrant antigen expression. In patients with T-ALL, the pre-T type is most common, according to the European Group for the Immunological Classification of Leukemias (EGIL) classification. Patients with T-ALL also generally lack aberrant antigen expression.

scholarly journals Clinical relevance of P-glycoprotein expression in de novo acute myeloid leukemia

Blood ◽  
1996 ◽  
Vol 87 (5) ◽  
pp. 1997-2004 ◽  
Author(s):  
G Del Poeta ◽  
R Stasi ◽  
G Aronica ◽  
A Venditti ◽  
MC Cox ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
De Novo ◽  
Survival Rates ◽  
Disease Free Survival ◽  
Normal Karyotype ◽  
Free Survival ◽  
Negative Phenotype ◽  
Acute Myeloid

Cytofluorimetric detection of the multidrug resistance (MDR)-associated membrane protein (P-170) was performed at the time of diagnosis in 158 patients with acute myeloid leukemia using the C219 monoclonal antibody (MoAb). In 108 of these cases the JSB1 MoAb was also tested. An improved histogram subtraction analysis, based on curve fitting and statistical test was applied to distinguish antigen-positive from antigen-negative cells. A marker was considered positive when more than 20% of the cells were stained. At onset, P-170 was detected in 43% of cases with C219 and in 73% of cases with JSB1. There was a strict correlation between C219 and JSB1 positivity, as all C219+ cases were also positive for JSB1 MoAb (P < .001). No relationship was found between sex, age, organomegaly, and MDR phenotype. Significant correlation was found between CD7 and both C219 and JSB1 expression (P < .001 and .001, respectively). C219-negative phenotype was more often associated with a normal karyotype (24 of 55 with P = .030). Rhodamine 123 (Rh123) staining and flow cytometry analysis showed a significantly decreased mean fluorescence in 51 C219+ and 38 JSB1+ patients compared to 42 MDR negative ones (P < .001). The rate of first complete remission (CR) differed both between C219+ and C219- cases and between JSB+ and JSB- ones (30.9% v 71.1% and 35.4% v 93.1%, respectively, P < .001). Of the 21 C219+ patients who had yielded a first CR, 19 (90.4%) relapsed, compared with 28 of 64 (43.7%) C219- patients (P < .001). Of the 28 JSB1+ patients in first CR, 17 (60.7%) relapsed relative to 8 (29.6%) of 27 JSBI- ones (P = .021). A higher rate of relapses among MDR+ compared with MDR- patients was observed both for C219 and JSB1 MoAbs taken separately (C219 80% v 44%; JSB1 52% v 27%), with no relationship to age. The survival rates (Kaplan-Meyer method) were significantly shorter both in C219+ patients and in JSB1+ cases (P < .001). Disease-free survival curves followed this same trend. The combination (C219- JSB1+) identified a subset of patients with an intermediate outcome compared to C219 positive cases. The prognostic value of both markers (C219 and JSB1) was confirmed in multivariate analysis. These results suggest that the assessment of MDR phenotype by flow cytometry may be an important predictor of treatment outcome.

Pediatric-Based Therapy for Young Adults with Newly Diagnosed Lymphoblastic Leukemia.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 2037-2037 ◽  
Author(s):  
Michael Rytting ◽  
Deborah A. Thomas ◽  
Anna R Franklin ◽  
Elias Jabbour ◽  
William Wierda ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Young Adults ◽  
De Novo ◽  
Residual Disease ◽  
Lymphoblastic Leukemia ◽  
Philadelphia Chromosome ◽  
Unknown Origin ◽  
High Dose ◽  
Days Of Therapy ◽  
Grade Iii

Abstract Abstract 2037 Poster Board II-14 Adolescents 14 to 21 years of age with de novo acute lymphoblastic leukemia (ALL) have improved outcomes if treated on pediatric chemotherapy regimens as opposed to adult regimens. Young adults with ALL may also benefit from chemotherapy modeled after pediatric regimens, though toxicities may be limiting. We report on 48 young adult patients between the ages of 12 to 40 years with de novo Philadelphia chromosome negative ALL treated with the augmented Berlin-Frankfurt-Munster (BFM) chemotherapy regimen. All patients have completed at least the initial 28 days of therapy (induction) consisting of high dose prednisone, pegylated asparaginase (PEG-asp), vincristine, daunorubicin and intrathecal treatments. The median age of the group was 20 yrs (14-36); 40 patients had pre-B ALL and 8 T-ALL, No infectious deaths were observed during induction. 45 (95%) patients achieved a remission by 29 days and 2 achieved remission after a 2 week extension of induction. One patient was refractory to therapy. 39 (81%) patients achieved a morphological marrow remission (<5% blasts) by day 15 of treatment (rapid early responders). Minimal residual disease (MRD) assessed by flow cytometry was negative at the end of induction for 30 (62%), positive in 10 (21%), suspicious in 6 (12%) and not available for 2 patients. In the 41 patients who completed 12 weeks of therapy, MRD was negative in 35 (85%) and positive in 6 (15%). 7 (15%) patients have relapsed or have refractory disease; 1 patient died in CR. Admission for fever of unknown origin with neutropenia occurred in 10 (21%) patients, an additional 10 (21%) patients had documented infections. Grade III-IV hepatic toxicity has been prominent: 22 (45%) increased transaminase, 14 (29%) hyperbilirubinemia. 9 (19%) patients had allergic reactions to PEG-asp, and 10 (21%) had thrombotic events. The majority of grade III-IV adverse events have been reversible. The median complete remission duration is 57 weeks (range 5-143). The overall survival at two years is 82%. In summary, this pediatric-based regimen for young adults with ALL effectively induces remission, both by morphology and by flow cytometry. Toxicity has been significant, but mostly transient and tolerable. Longer follow-up is needed to determine the long-term efficacy of this regimen in young adults with ALL. Disclosures: Rytting: Enzon: Speakers Bureau. Jabbour:Bristol-Myers Squibb: Speakers Bureau; Novartis: Speakers Bureau.

Multiparameter Flow Cytometry as a Powerful Tool

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. SCI-29-SCI-29
Author(s):  
Brent Wood
Keyword(s):  
Flow Cytometry ◽  
Myeloid Leukemia ◽  
Current Flow ◽  
Lymphoblastic Leukemia ◽  
Early Time ◽  
Time Points ◽  
Flow Cytometric ◽  
Laboratory Services ◽  
Higher Sensitivity ◽  
Acute Myeloid

Abstract Minimal residual disease (MRD) detection following therapy is rapidly becoming the standard of care for patients with acute leukemia. Flow cytometry is one of the principal technologies employed for MRD monitoring due its rapid turnaround time, similarity to diagnostic immunophenotyping, and widespread availability of instrumentation in clinical laboratories. The immunophenotypic identification of neoplastic cells relies on the altered expression of proteins or antigens by neoplastic cells in comparison to their normal counterparts of similar lineage and maturational stage, and represents an integration of alterations in the underlying genetic program that are responsible for neoplasia. However, important technical and interpretative differences exist between diagnostic immunophenotyping and MRD monitoring that require special attention to ensure consistent quality, not the least of which is appropriate assay validation. In addition, there is also significant variability in the methods of sample preparation, reagent panels used, and data analysis strategies employed in clinical flow cytometry laboratories and this variability extends to MRD testing. The consequence is variability in quality between laboratories for MRD testing, even laboratories considered knowledgeable or experienced. This lack of standardization represents a major challenge to widespread implementation of MRD monitoring by flow cytometry. Consequently, on-going efforts by the Childrens Oncology Group and Foundation of the National Institute of Health are focused on improving standardization of B lymphoblastic leukemia MRD testing for clinical trials and ultimately all patients. Nevertheless, in experienced laboratories using a standardized protocol, MRD monitoring by flow cytometry in B lymphoblastic leukemia has been shown to be capable of producing reproducible results at both the technical level and relative to patient outcomes on clinical trials, emphasizing that the technology itself allows for reproducible testing and that the current variability is largely due to implementation details and interpretive skills. Whether this degree of comparability can be achieved for T lymphoblastic leukemia or acute myeloid leukemia remains to be demonstrated. A related issue is the level of sensitivity that is both achievable and desirable for MRD monitoring at particular time points after therapy. Current flow cytometric assays have a routine limit of detection at early time points after therapy of roughly 0.01% of nucleated cells for acute lymphoblastic leukemia and 0.1% for acute myeloid leukemia with a higher sensitivity possible for subsets of patients having either more frankly aberrant immunophenotypes or reduced background populations of similar immunophenotype. Interestingly, our recent comparison of flow cytometry with high throughput sequencing in B lymphoblastic leukemia suggests that increased assay sensitivity does not necessarily improve risk stratification at early time points and that the moderate sensitivity of current flow cytometric assays is adequate for this purpose. However, higher sensitivity assays will likely be more important at later time points further from therapy. Multiple studies have now demonstrated the prognostic significance of MRD detection in acute leukemia after therapy or prior to bone marrow transplantation using flow cytometry. This raises the possibility as to whether the assessment of MRD after therapy can be used not only to assess response to therapy, but as a surrogate biomarker for outcome to expedite the new drug approval process. Disclosures Wood: Amgen: Honoraria, Other: Laboratory Services Agreement; Seattle Genetics: Honoraria, Other: Laboratory Services Agreement; Juno: Other: Laboratory Services Agreement; Medimmune: Other: Laboratory Services Agreement; Pfizer: Other: Laboratory Services Agreement.

Activating FLT3 mutations in CD117/KIT+ T-cell acute lymphoblastic leukemias

Blood ◽  
2004 ◽  
Vol 104 (2) ◽  
pp. 558-560 ◽  
Author(s):  
Elisabeth Paietta ◽  
Adolfo A. Ferrando ◽  
Donna Neuberg ◽  
John M. Bennett ◽  
Janis Racevskis ◽  
...  
Keyword(s):  
T Cell ◽  
Receptor Tyrosine Kinase ◽  
Myeloid Leukemia ◽  
De Novo ◽  
Lymphoblastic Leukemia ◽  
Genetic Aberrations ◽  
Constitutive Activation ◽  
Activating Mutations ◽  
Flt3 Mutations ◽  
Acute Myeloid

Abstract Activating FLT3 mutations are the most common genetic aberrations in acute myeloid leukemia (AML), resulting in the constitutive activation of this receptor tyrosine kinase (RTK), but such mutations are rarely found in acute lymphoblastic leukemia (ALL). Here we describe a unique subset of de novo adult T-cell ALL (T-ALL) cases that coexpress CD117/KIT and cytoplasmic CD3 (CD117/KIT+ ALL). Activating mutations in the FLT3 RTK gene were found in each of 3 CD117/KIT+ cases that were analyzed, but not in 52 other adult T-ALL samples from the same series that lacked CD117/KIT expression. Our results indicate the need for clinical trials to test the efficacy of drugs that inhibit the FLT3 RTK in this subset of patients with T-ALL. (Blood. 2004;104:558-560)

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