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.