Myeloid Antigen Expression in Childhood Acute Lymphoblastic Leukemia and Its Relevance for Clinical Outcome in Indonesian ALL-2006 Protocol

Hematological, clinical, immunophenotypic characterization, and treatment outcomes of prognostically significant genetic subtypes of B-lineage acute lymphoblastic leukemia: A report of 1021 patients from India

BACKGROUND

The published literature on hematological, clinical, flowcytometric-immunophenotyping, and minimal residual disease outcomes of the prognostically important genetic subtypes of acute lymphoblastic leukemia (ALL) is scarce from low-income countries. For newer classifications such as BCR::ABL1-like ALLs, the scarcity of patient-level data is even more pronounced.

METHODS

The authors performed comprehensive detection of recurrent gene fusions and BCR::ABL1-like ALL cases followed by immunophenotypic profiling and obtained clinical outcome parameters for a large cohort (n = 1021) of patients from India. This cohort included a significant number of patients with BCR::ABL1-like ALL subtype and other genetic subtypes of ALL.

RESULTS

Patients with BCR::ABL1-positive and BCR::ABL1-like ALL were significantly older, had male preponderance, and expressed a higher white blood cell count than BCR::ABL1-negative cases (p < .05). Logistic regression modeling of B-lineage-ALL (B-ALL) subtypes revealed that cluster of differentiation (CD)36 is a strong statistically significant predictive marker of BCR::ABL1-like ALL (p < .05). Furthermore, patients with BCR::ABL1-like ALLs show a significantly higher frequency of CD36 expression compared to BCR::ABL1-negative ALLs (p < .05). In terms of clinical symptoms, lymphadenopathy is a strong statistically significant predictive marker in BCR::ABL1-like ALLs compared to BCR::ABL1-negative ALL cases (p < .05). In terms of treatment outcomes, minimal residual disease (MRD) positivity in BCR::ABL1-positive ALL cases were statistically significant (p < .05), and BCR::ABL1-like ALL cases had high MRD-positivity as compared to BCR::ABL1-negative ALL cases but did not show statistical significance.

CONCLUSIONS

The findings evince the use of novel therapies and personalized treatment regimens to improve the overall survival of the newer incorporated entities in B-ALLs. This is the first report characterizing the hematological, clinical, flowcytometric-immunophenotyping, and minimal residual disease outcomes of the prognostically significant subtypes of ALLs in patients from India.

PLAIN LANGUAGE SUMMARY

Characterizing the hematological, clinical, flowcytometric-immunophenotyping, and minimal residual disease outcomes of the prognostically significant subtypes (n = 1021) of acute lymphoblastic leukemia (ALLs) in patients from India. We have made two independent logistic regression models of cluster of differentiation (CD) markers and clinical symptoms to differentiate prognostically significant subtypes of ALLs. Logistic regression analysis of CD markers revealed CD36 as a strong predictor in BCR::ABL1-like ALL cases compared to BCR::ABL1-negative ALL cases. Logistic regression analysis of clinical symptoms revealed lymphadenopathy significantly predicts BCR::ABL1-like ALLs (p < .05). In terms of treatment outcomes, BCR::ABL1-positive ALL had statistically significant minimal residual disease (MRD) (p < .05), and BCR::ABL1-like ALL cases had high MRD-positivity but did not show statistical significance as compared to BCR::ABL1-negative ALLs.

Childhood acute lymphoblastic leukemia: Four years evaluation of protocols 2013 and 2016 in a single center in Indonesia, a lower-middle-income country

BACKGROUND

The prognosis of childhood acute lymphoblastic leukemia (ALL) in Indonesia, a lower-middle-income country (LMIC), is lower than in high income countries (HICs). The Indonesian ALL2013 protocol resulted in too many toxic deaths (21%) and abandonments (11%). Therefore, we drafted an adapted protocol, ALL2016. Main changes: no anthracyclines in standard risk (SR), prednisone replaced dexamethasone at induction in high risk (HR), and anthracyclines and cyclophosphamide were rescheduled in HR.

PROCEDURE

Patients (aged: 1-18 years) were stratified into SR and HR. HR was defined as age over 10 years, leucocyte count over 50 × 10⁹ /L, central nervous system (CNS) involvement, mediastinal mass, T-cell phenotype, testicular involvement, or poor prednisone response.

RESULTS

ALL2013 included 174 patients (106 SR and 68 HR) and ALL2016 188 (91 SR and 97 HR). Although the number of HR patients was significantly higher in ALL2016 (51.6% vs. 39.1%; p = .017), the outcome of ALL2016 improved over ALL2013 (4-year-probable overall survival (pOS) 60.1% vs. 50.0%; p = .042 and 4-year-probable event-free survival (pEFS) 49.5% vs. 36.8%; p = .018). ALL2016 showed a nonsignificant advantage for SR patients (4-year-pEFS 56.0% vs. 47.2%; p = .220 and 4-year-pOS 70.3% vs. 61.3%; p = .166), but less toxic deaths (7% vs. 20%; p = .011). In HR group, the outcomes were significantly better in ALL2016 (4-year-pEFS 43.3% vs. 20.6%; p = .004; 4-year-pOS 50.5% vs. 32.4%; p = .014) especially due to less relapses (31% vs. 62%; p = .001). Isolated CNS relapses went down from 18 to 8% in HR (p = .010) and 11 to 5% in SR (p = .474). Both SR and HR showed lower numbers of abandonment in ALL2016 (6% vs. 14%; p = .039).

CONCLUSIONS

Overall ALL2016 results improved over ALL2013. Modest changes in protocol resulted in less initial toxicity and abandonments.

Characterization of the immunophenotypic aberrancies with respect to common fusion transcripts in B-cell precursor acute lymphoblastic leukaemia - a report of 986 Indian patients

Objective:

Based on the immunophenotype, acute lymphoblastic leukemia (ALL) can be categorized into B-cell or T-cell lineages. B-cell precursor ALL (BCP-ALL) cases show various genetic/molecular abnormalities, and varying frequencies of chimeric fusion transcripts in BCP-ALL cases are reported from different parts of the world. We studied the immunophenotypic aberrancy profiles of a large number of BCP-ALL cases with respect to various common chimeric fusion transcripts.

Materials and Methods:

Flow cytometric immunophenotyping and multiplex reverse-transcription polymerase chain reaction assays were performed for 986 BCP-ALL cases.

Results:

Among 986 BCP-ALL cases, the incidence of various fusion transcripts was 38.36% in adult cases and 20.68% in pediatric cases. Adult BCP-ALL patients with t(9;22)(BCR-ABL1) fusion transcripts and expression of aberrant myeloid markers were significantly older at presentation (p=0.0218) with male preponderance (p=0.0246) compared to those without aberrant myeloid expression. In pediatric patients with the t(12;21)(ETV6-RUNX1) chimeric fusion transcript, aberrant expression of CD13 was observed in 39.13%, CD33 in 36.95%, and CD117 in 8.69% of patients, respectively. Pediatric BCP-ALL patients with the ETV6-RUNX1 fusion transcript and expression of aberrant myeloid markers were not significantly different compared to those without with respect to demographic and clinical/hematological characteristics (p=0.5955). Aberrant myeloid markers were rarely or never expressed in pediatric and adult BCP-ALL patients with the t(4;11)(KTM2A-AF4) and t(1;19)(TCF3-PBX1) fusion transcripts.

Conclusion:

Aberrant myeloid markers were frequently expressed among BCP-ALL patients with the t(9;22)(BCR-ABL1) and t(12;21)(ETV6-RUNX1) fusion transcripts. However, BCP-ALL patients with the t(4;11)(KTM2A-AF4) and t(1;19)(TCF3-PBX1) fusion transcripts rarely or never expressed aberrant myeloid markers. Aberrant myeloid CD markers can be used in predicting chimeric fusion transcripts at baseline so as to plan appropriate tyrosine kinase inhibitor therapy in cases of BCP-ALL with specific chimeric fusion transcripts. This study has delineated the relationship of chimeric fusion transcripts with the aberrant expression of myeloid markers in a large cohort of BCP-ALL cases.

Distribution of subtypes and immunophenotypic characterization of 1379 cases of paediatric acute leukaemia

Objectives:

Acute leukaemia is the most common and highly curable childhood malignancy; subtyping and identification of antigens via immunophenotyping helps in treatment plan as well as minimal residual disease monitoring.

Methods:

This retrospective study was conducted at the Haematology section of the clinical laboratories of Ziauddin University Hospital and The Indus Hospital, Karachi conducted at January 1st, 2012 to December 31^st, 2017. The study included 1379 cases of de novo acute leukemia from 2012 to 2017. Among these, 80% were diagnosed by using four color flowcytometry (FACS Calibur), 9% and 11% via immunohistochemistry on bone marrow trephine biopsy samples and morphological examination respectively.

Results:

The mean age of patients was 7.4 ± 4.3 years while male to female ratio was 1.75:1. Lymphoblastic leukaemia accounted for 77.2% and myeloid leukaemia 21.2%. Amongst lymphoblastic lineage, B-ALL was 80.4% while T-ALL was 19.6%. Among the phenotypic expression of B-ALL, CD79a (99.8%) had the highest positivity. In B-ALL, CD13 (29.8%) was the most common aberrant myeloid marker. Aberrant expression of CD79a observed in 11.1% of T-ALL cases. In non APL AML, aberrant expression of CD79a and CD19 was observed in 6.6% and 5.5% of cases respectively.

Conclusion:

Overall immunophenotypic profile, expression of aberrant phenotypes and subtype distribution in our patients was similar to international literature except for a relatively high frequency of T-ALL which was discordant from the western data.

Characterization of Immunophenotypic Aberrancies in Adult and Childhood Acute Lymphoblastic Leukemia: Lessons from Regional Variation

Background & Objective:

Although the antigen expression patterns of acute lymphoblastic leukemia (ALL) are well known, this study attempted to evaluate commonly used immune markers for immunophenotyping of acute leukemia to set the minimum of necessary diagnostic panels by flow cytometry.

Methods:

This study evaluated 89 patients referred from all over the country to the Iranian Blood Transfusion Organization (IBTO) in Tehran from 2013 to 2015. We compared the immunophenotype patterns of childhood and adult ALLs including 69(77.5%) B-cell lymphoblastic lymphoma (B-LBL), 2(2.2%) Burkitt’s lymphoma (BL), and 18(20.2%) T-cell lymphoblastic lymphoma (T-LBL) cases using flowcytometry with broad antibody panel.

Results:

CD19 and CD79a were the most frequent markers for B-LBL while CD7 was the most sensitive marker in T-LBL; the frequency of CD7, CD3, and CD5 antigens were 100%, 38.9%, and 88.9%, respectively. TdT+/CD34+ was significantly higher in adult B-LBLs than children, which indicates blast cells are more immature in adults. In addition, CD10 and cCD79a were significantly higher in children with B-LBL like as CD5 and CD8 in children with T-LBL. Aberrant phenotypes including CD13, CD33, CD7, and CD117 were found in 7(10.1%) cases of B-LBL. These phenotypes were CD117, HLA-DR, and CD33 in 7(38/9%) cases of T-LBL. Expression of CD117 aberrant myeloid antigen was significantly more associated with T-LBL than with B-lineage ALL.

Conclusion:

Significant differences were observed in antigen-expression patterns between adult and childhood ALLs. Further studies are needed to correlate specific markers with recurrent cytogenetic abnormalities and prognosis with therapeutic response.

Spectrum and Immunophenotypic Profile of Acute Leukemia: A Tertiary Center Flow Cytometry Experience

Background

For diagnosis, sub-categorization and follow up of Acute Leukemia (AL), phenotypic analysis using flow cytometry is mandatory.

Material and methods

We retrospectively analyzed immunophenotypic data along with cytogenetics/molecular genetics data (wherever available) from 631 consecutive cases of AL diagnosed at our flow cytometry laboratory from January 2014 to August 2017.

Results

Of the total 631 cases, 52.9% (n=334) were acute lymphoblastic leukemia (ALL), 43.9% (n=277) acute myeloid leukemia (AML), 2.2% (n=14) mixed phenotypic acute leukemia (MPAL), 0.5% (n=3) acute undifferentiated leukemia (AUL) and 0.5% (n=3) chronic myeloid leukemia in blast crisis (CML-BC). ALL cases comprised of 81.7% (n=273/334) B-cell ALLs (95.2%, n=260/273 common B-ALLs and 4.8%, n=13/273 Pro B-ALLs). CD13 was the commonest cross lineage antigen, expressed in B-ALL (25.6%, n=70/273), followed by CD33 (17.9%, n=49) and combined CD13/CD33 (11.3%, n=31/273) expression. T-ALLs constituted 18.3% (n=61/334) of total ALLs and included 27.9% (n=17/61) cortical T- ALLs. CD13 was commonest (32.7%, n=20/61) aberrantly expressed antigen in T-ALLs, followed by CD117 (19.1%, n=9/47). AML cases included 32.1% (n=89/277) AML with recurrent genetic abnormalities, 9.0% (n=25/277) with FLT3/NPM1c mutation and 58.9% (n=163/277) AML NOS including 14.7% (n=24/163) AML M4/M5, 1.8% (n=3/163) AML M6 and 3.7% (n=6/163) AML M7. In AMLs, CD19 aberrancy was the most common (20.2%, n=56/277) followed by CD56 (15.8%, n=42/265).

Conclusions

In this study, we document the spectrum, correlate the immunophenotype with genetic data of all leukemias, especially concerning T-ALL where the data from India is scarce.

Immunophenotypic aberrancies in acute lymphoblastic leukemia from 282 Iraqi patients

INTRODUCTION

The identification of aberrancies in leukemia-associated immunophenotype (LAIP) of acute lymphoblastic leukemia (ALL) is quite important in the assessment of minimal residual disease (MRD). This study, the first from Iraq, aimed to assess the frequency and patterns of LAIP among Iraqi patients with ALL, to establish future strategies for evaluating MRD.

METHODS

A total of 282 newly diagnosed Iraqi ALL cases were analyzed with six-parameter flow cytometry using a panel of 29 monoclonal antibodies.

RESULTS

Immunological subtyping revealed that 85.5% of cases were B-ALL and the remainder T-ALL. LAIP was detected in 97.1% of B-ALL, and in 26.8% of T-ALL. The asynchronous maturation-associated antigen patterns in B-ALL were CD10^strong+ /TdT^dim+ , CD38^dim+ /CD34⁺ , CD10^dim+ /CD34⁺ , CD10^strong /CD20^strong+ , CD20^strong+ /CD34^+, and CD45^dim+ /CD20^strong+ in 84.6%, while the cross-lineage myeloid expression was seen in 81.3% and aberrant T-cell antigen expression in 6.2%. For T-ALL, asynchronous maturation-associated antigen patterns included the following: CD1a⁺ /CD5⁺ /sCD3⁺ and CD34⁺ /sCD3⁺ in 12.2%. Myeloid and B-cell antigen expression were each identified in 7.3% of T-ALL. No significant differences in LAIP were found between children and adults.

CONCLUSION

The high rates and the patterns of LAIP particularly in Iraqi B-ALL patients may allow the development of more cost-effective strategies for MRD monitoring.

T-cell acute lymphoblastic leukemia with co-expression of CD56, CD34, CD117 and CD33: A case with poor prognosis

T-cell acute lymphoblastic leukemia (ALL) is an aggressive hematological malignancy, accounting for ~25% of all adult cases of ALL. We herein report a case of T-cell ALL exhibiting aberrant CD34, CD56, CD33 and CD117 expression in addition to T-cell markers, which did not respond to induction treatment. A 55-year-old woman was admitted to our hospital with a sore throat unresponsive to medication for 1 month. The laboratory examination revealed pancytopenia and the peripheral blood smear examination revealed blast cells. On flow cytometric analysis, the blast cells were found to be positive for cytoplasmic CD3, CD2, CD5, CD7, CD34, CD56, CD33 and CD117, and negative for myeloperoxidase, CD13, CD11b, CD15, CD19, CD79a, CD22 and CD10. The patient was diagnosed with T-cell ALL according to the 2008 World Health Organisation classification. The patient did not respond to Hyper-cyclophosphamide, vincristine, adriamycin and dexamethasone (CVAD) course A treatment and succumbed to the disease during Hyper-CVAD course B treatment. To the best of our knowledge, this is the first report of aberrant co-expression of the natural killer cell marker CD56, myeloid cell markers CD117 and CD33 and stem cell marker CD34 in a patient with T-cell ALL. This appears to be associated with an unfavorable outcome, despite the use of intensive chemotherapy.