The Immunophenotype of Adult T Acute Lymphoblastic Leukemia in Morocco

Abstract

Background: There is paucity of detailed studies of adult T cell acute lymphoblastic leukemia (T-ALL) in developing countries reflecting the condition of these patients including clinical and biological features. Objective: This study was carried out to analyze the immunophenotypic characteristics of 40 Moroccan patients with T-ALL and its association with biological and clinical features. Patients and Methods: Between 2006 and 2009, 130 adult patients diagnosed with acute lymphoblastic leukemia (ALL) were immunophenotyped by 3-color flow cytometry using a panel of monoclonal antibodies. Cases presenting features of a T-lineage phenotype were subjected to detailed analysis including immunophenotypic, clinical and biological parameters. Results: Proportion of T-ALL among ALL Moroccan patients was 31.0%. Median age of patients was 28 years. Twenty-nine patients were females and 11 were males. 45.0% of patients (18/40) had features of immature T-ALL stages (pro-T and pre-T ALL), 30.0% (12/40) of CD1a+ cortical T-ALL stage and 25.0% (10/40) had a characteristic phenotype of medullary T-ALL. The frequencies of progenitor cell markers CD10, CD34 and TdT expression were 14.0; 57.5% and 50.0% respectively. The aberrant expression of B lineage associated antigen CD79a were positive in 20.5% of the cases and the aberrant expression of myeloid antigens CD13 and/ or CD33 was found in 22 (55.0%) cases. No significant association was encountered between TdT, CD34 or myeloid antigens positivity and high risk features at presentation as age, sex, and white blood cells. However, myeloid antigens (CD13 and/or CD33) was significantly associated with T-cell maturation stages (p = 0.009). Conclusion: To the best of our knowledge, this is the first report from North Africa of immunophenotypic study on adult T-ALL. Our findings indicate that the proportion of T-ALL among ALL in Morocco is similar to that reported in others Mediterranean countries like France and Italy and that myeloid-associated antigens expression is frequently associated with immature immunophenotype.

Immunophenotypic aberrancies in acute lymphoblastic leukemia from 282 Iraqi patients

“…Our figures for the proportion of B‐ALL and T‐ALL at 85.5%, and 14.5% are virtually identical to the 84.5% and 15.6% reported by the Middle East Childhood Cancer Alliance in 2014 . It is also consistent with most studies worldwide . Moreover, our relative rates of 88% for the common B‐ALL and 73.2% for cortical T‐ALL subtypes were within the ranges for these two subtypes reported worldwide at 67.2%‐90% and 31.5%‐80.4%, respectively …”

“…With regard to cross‐lineage antigens expression in T‐ALL, B‐cell antigen expression (cCD79a) constituted around a quarter of LAIP detected. CD79a was also noted as a frequent LAIP in some studies, while others documented CD19 as the most frequent B‐cell marker aberrancy in their T‐ALL . On the other hand, the frequency of myeloid antigens expression in T‐ALL was 7.3% in the current series.…”

“…A frequent problem of FC is the discrimination of residual B‐ALL from hematogones. During the normal B‐cell maturation process, CD10 together with nTdT and CD34 are the earliest detectable antigens and they are involved in regulated stromal‐dependent B‐cell lymphopoiesis . These three markers are later down‐regulated as CD20 is gradually expressed, and normal B‐cell precursors (hematogones) differentiate into more mature B cells.…”

Immunophenotypic Profile of T Acute Lymphoblastic Leukaemia in a Tertiary Care Centre - Our Experience

“…CD1a was positive in a little more than half of all cases (51.43%). A study in Moroccan children by Lahjouji et al found an excess of the common thymocyte subtype (80.4%) displaying reactivity with CD1a as compared with the frequency reported by others [8].…”

Three Patients with Multiple Myeloma Developing Secondary Lymphoblastic Leukemia: Case Reports and Review of the Literature

“…In the past, it was believed that the prognosis of ALL showing expression of myeloid antigen (Mye(+)ALL) was poorer than that of ALL with no myeloid antigen expression (Mye(–)ALL). However, recent papers suggested that there was no significant difference ­between the prognosis of these 2 groups (22–23–25). As previously mentioned, our 3 cases were different from those described in other reports.…”