Clinical and immunophenotypic profiles of children diagnosed with acute leukemia at Moi Teaching and Referral Hospital, Eldoret, Kenya

Abstract

Background: Acute leukemia is a heterogenous group of diseases comprising of several subtypes that differ in their clinical manifestations and response to treatment. Appropriate diagnosis and risk stratification is important in improving treatment outcome. At Moi Teaching and Referral Hospital, there is paucity of data on immunophenotypic subtypes of acute leukemia. Objectives: To determine the clinical and immunophenotypic profiles of children diagnosed with acute leukemia at Moi Teaching and Referral Hospital (MTRH). Methods: This was a cross sectional study carried out between January 1st 2015 and January 1st 2016. Children with a presumptive diagnosis of acute leukemia based on hemogram and peripheral blood film had bone marrow aspirate (BMA) done. Acute leukemia was confirmed by immunophenotyping of the BMA samples using a four colour BD FACS caliburTM flow cytometry machine with a standardized panel of monoclonal antibodies for acute lymphoblastic and myeloblastic cells. Demographic, clinical and BMA morphological characteristics at diagnosis were documented. Data analysis was performed on the confirmed cases of acute leukemia using SPSS Version 21 and presented in tables and bar graphs. Tests of associations was done using chi square test while concordance between morphological and flow cytometry diagnosis was determined by Kappa coefficient. Results: Fifty two children with a presumptive diagnosis of acute leukemia had BMA done, 34(65%) had acute leukemia on BMA morphology while 41(78.8%) were confirmed by flow cytometry. Twenty one (51.2%) were males, 29 (72.5%) were less than nine years while 24 (60%) had symptoms for more than one month. There were more ALL than AML participants presenting with symptoms for longer than one month prior to diagnosis (p=0.036). Fever was present in 31(75.6%) participants, anemia in 30 (73.2%), hepatomegaly in 21 (51.2%) while 7(18.2%) had central nervous system involvement at diagnosis. Generalized lymphadenopathy was more common in ALL than AML patients. In eighteen (45%) participants hemoglobin level was less than 7g/dl and in 13(32.5%) white blood cell count was above 50 x 109/uL. Platelet count was <50 x 109/uL in 84% of ALL patients and only 50% of AML patients. In 8/41(20%) cases, a conclusive diagnosis of acute leukemia could not be made on BMA morphology but were appropriately diagnosed on flow cytometry. On immunophenotyping, 26 (63 %) participants had ALL while 15(37 %) had AML.T cell ALL constituted 27% of all ALL cases. Conclusion: Fever and anemia are the most common clinical feature at diagnosis of acute leukemia. Proportion of high risk leukemia immunophenotype at MTRH is relatively high. Up to one fifth of leukemia cases are not conclusively diagnosed when morphology alone is used. Recommendation: Flow cytometry should be routinely used alongside morphology to improve diagnosis and risk stratification of acute leukemia.