Background: Aberrant phenotypes in acute leukemia (AL) have variable frequency and their prognostic relevance is controversial and dissimilar results have been reported by different groups.
Objectives: To determine frequency of aberrant marker expression in acute leukemia at South Egypt Cancer Institute (SECI) and to relate these expression with patient outcome and cytogenetic abnormality.
Patients and Methods: A retrospective study was conducted at SECI over a period of ten years. Total 1134 AL patients of both genders and all age groups were included in the study, of them 458 were diagnosed as acute myeloid leukemia (AML), 494 were diagnosed as B-acute lymphoblastic leukemia (B-ALL), 157 were diagnosed as T-ALL and 25 were diagnosed as biphenotypic AL (BAL).
Results: Aberrant phenotypes were found in 91 (19.9%) cases of AML, 148 (30%) cases of B-ALL and 63 (40.1%) cases of T-ALL. CD56 was the most frequent aberrant marker in AML cases, CD33 in B-ALL cases and CD10 in T-ALL cases. Aberrant expression carried no significant prognostic value in AL when compared to those without aberrant expression except for that in B-ALL was a significant poor prognostic factor for relapse. CD33 was the most frequent aberrant marker in BCR/ABL positive B-ALL patients with aberrant expression, CD33 in the only t(1;19) positive B-ALL case and also the aberrantly expressed in the only t(8;14) positive B-ALL case, CD56 in PML/RARA positive AML patients and CD19 was aberrantly expressed in the two AML cases with t (8;21) and also the aberrant expressed marker in the only AML case with Monosomy 7.
Conclusion: We conclude that aberrant phenotypes were present with a considerable frequency among AL patients at SECI and may be of poor prognosis only in B-ALL. Immunophenotyping may be related to particular cytogenetic patterns. But need larger studies to confirm.