Aberrant antigen expression in patients with acute leukemias : experience of King Hussein medical center in Jordan

الملخص EN

Objective: To assess the frequency of aberrant antigens expression in acute leukemias and their possible prognostic significance in a group of Jordanian patients.

Methods: A retrospective study of acute leukemia cases was conducted at King Hussein Medical Centre over 3 years (January 2012 to December 2014).

A total of 368 cases of acute leukemia diagnosed by multi parameter flow cytometry performed on peripheral blood and/ or fresh bone marrow aspirates.

The co-expression of myeloid markers on lymphoblasts and lymphoid markers on myeloblasts was analyzed.

The findings were correlated with remission status.

Results: 368 cases of acute leukemias were retrieved; these were: 192 (52%) cases of acute myeloid leukemia (AML), 173 cases (47%) of acute lymphoblastic leukemia (ALL) and 3 cases (1%) with mixed phenotype acute leukemia.

Aberrant immunophenotype expression was observed in 44 (23%) AML cases and in 50 (29%) of ALL cases.

CD7 was the commonest aberrant lymphoid marker expressed in AML which was noted in 19/44 (43%).

Of the aberrant B-ALL cases, CD33 were expressed in 18/38 (47%) and CD13 in 14/38 (37%).

212 out of 368 cases (58%) were followed up in our centre during treatment program and stratified into remission and non-remission groups based on morphologic assessment of peripheral blood and bone marrow aspirates.

These tests were carried out at day 21 of induction therapy, completion of treatment and any clinical deterioration during the study period.

70% of non-remission ALL and 53% of non-remission AML had aberrant phenotypes.

No significant differences were noted between classical and aberrant acute leukemias regarding age, sex and blasts count.

Conclusion: The incidence of aberrant antigen expression in acute leukemia was comparable with most published international data.

Such aberrant antigen expression may represent a poor prognostic indicator among this group of Jordanian patients.

These findings may help to recognize patients with high risk group and low remission rate.

Further studies are needed to confirm the correlation between aberrant phenotypes with prognosis and therapeutic response of acute leukemia.