Immunophenotype of Acute Lymphoblastic Leukemia: The Experience of University Hospital Centre Casablanca - Morocco.

BACKGROUND: Acute lymphoblastic leukemia (ALL) encompasses a group of lymphoid neoplasms that morphologically and immunophenotypically resemble B-lineage and T-lineage precursor cells. Our objective is to describe the immunophenotypic aspects of acute lymphoblastic leukemia (All) diagnosed by flow cytometry at the hematology laboratory of IBN ROCHD University Hospital Center and to compare them with those reported in other series. METHODS: This is a descriptive study over a period from August 2016 to October 2021, during a 5 year-and-2-month period. Immunophenotyping was performed at the flow cytometry unit on a Beckman-Coulter with 6 colors and 2 lasers in the hematology laboratory of the same hospital and data was collected retrospectively from the patients' files, their medical prescription files, kalisil software, and a data collection form we have established. RESULTS: The 440 patients had ages ranging from 1 month to 76 years, with a median of 9.5 years and the overall male-to-female ratio was 1.44. The immunological subtyping revealed that 82.5% of cases were B-ALL and 17.5% were T-ALL; of these B-ALL cases 230 (63.36%) were children (range: 0.1 - 15 years) and 134 (36.91%) were adults (range: 16 - 76 years); T-ALL were distributed in both age groups, 49 cases (37.7%) were children (range: 2 - 15 years) and 28 (21.56%) were adults (range: 18 - 63 years). All patients presented at least one abnormal blood count; thrombocytopenia has been observed in 89.4% of cases, anemia in 86.5% of cases, hyperleukocytosis in 79.8% of cases, leukopenia in 10.6% of cases, and pancytopenia in 4.8% of cases. The frequency of B-cell markers in B-ALL was found to be 363 (100%) for CD19, 323 (88.94%) for CD10, 290 (80%) for CD79a, and 73 (20%) for CD20. CD34 expression was found in 73 (20%) cases of B-ALL. HLA-DR was found in 54 (15%) cases, while TdT was found in 43 (13%) cases. Aberrant expression of myeloid antigens was found in 94 (26%) cases of B-ALL. Among T-ALL, the positivity of CD3 and CD7 was 100% (77 cases), while CD5 was positive in 58 (75%) cases. CD34 expression was found in only 19 cases of T-ALL. CD4 and CD8 expression was checked in only 9 adult patients and 4 pediatric cases. Out of them, 77.82% of cases were negative for both CD4 and CD8. CD4 and CD8 double positivity was seen in only 11.1% of cases, and 22.4% of cases showed either CD4 or CD8 positivity. CONCLUSIONS: We concluded that our study was similar to reports in the Americas and Europe, and it was the first large one that describes the immunophenotypic profile of ALL in the Moroccan population.

[Prognostic value of residual disease detection in acute myeloid leukemia with normal karyotype and negative FLT3-ITD]. / Intérêt pronostique de la détection de la maladie résiduelle dans les leucémies aiguës myéloïdes avec caryotype normal et FLT3-ITD négatif.

INTRODUCTION: Complete remission (CR) in patients with acute myeloid leukemia (AML) is still morphologicaly defined, thus corresponding to a wide range of tumor burden. OBJECTIVES: we aimed to evaluate the residual disease (MRD) status in patients with AML, as well as perform a molecular analysis of the FLT3/ITD gene in patients with normal karyotype. MATERIAL AND METHODS: adult patients with AML, diagnosed according to the WHO 2016 criteria, were included. MRD was detected using flow cytometric techniques after induction treatment resulting in CR. RESULTS: thirty patients met our inclusion criteria. 83 % of them had an intermediate risk status, 67 % of which (20/30) having a normal karyotype. MRD and leukemic stem cell (LSC) positivity in this group was predominant with considerable decrease in benign progenitor count. The relapse-free survival (RFS) in the group of MRD negative patients with normal cytogenetics and non-mutated FLT3 gene was better than the RFS in all of our patients studied. CONCLUSION: MRD and LSC are powerful prognostic factors for relapse. They should be routinely integrated to guide better management of AML.

Aberrant Phenotype in Acute Myeloid Leukemia: Hematology Laboratory Experiment of the University Hospital of Casablanca, Morocco.

BACKGROUND: Aberrant phenotypes in acute myeloid leukemia have variable frequencies and their prognostic value with adverse hematological and other biological prognostic factors is still controversial, despite several reports of clinical significance. To date, no study has been reported evaluating the incidence of these phenotypic aberrations in the Moroccan population. The aim is to evaluate the incidence of aberrant phenotype expressions in acute myeloid leukemia and correlate their presence with the different AML subtypes, and clinical and biological characteristics in Moroccan patients. METHODS: Fifty-four AML patients were diagnosed according to WHO classification 2016 criteria. Immunopheno-typing by flow cytometric analysis was performed to evaluate aberrant phenotypes on myeloblasts. RESULTS: The occurrence of lymphoid antigens in AML was higher (51.8%), which was closer to that reported in the literature. CD7 has been revealed to be the most commonly expressed lymphoid antigen. Besides, CD19 was expressed in all 3.7% of M2 AML subtype. However, we could find no statistically significant differences between these aberrant phenotypes regarding FAB subtypes or clinical and biological outcomes. The great majority of AML cases showed asynchronous expression (57%) with significant differences regarding FAB subtypes. CONCLUSIONS: Aberrant phenotypes might be associated with different leukemia subtypes that should be studied for a better understanding of their biological significance and adding important information for prognosis and, at the same time, could be of help when looking for minimal residual disease during morphologic remission.