Date of Award

2024

Degree Type

Dissertation

Degree Name

Master of Medicine (MMed)

First Advisor

Elizabeth Kagotho

Second Advisor

Geoffrey Omuse

Third Advisor

Nancy Okinda

Department

Pathology (East Africa)

Abstract

Introduction; Acute leukaemia is a heterogeneous group of haematological malignancies. It is categorized depending on the immature cells that proliferate and replace the normal tissue in the bone marrow. The broad categories are acute myeloid leukaemia if the immature cells are myeloblasts and acute lymphoid leukaemia if lymphoblasts. Other rare categories are blastic plasmacytoid dendritic cell neoplasm (BPDCN) and acute leukaemias of ambiguous lineage which include acute undifferentiated leukaemia and mixed phenotype acute leukaemias (MPALs). The classification is important as the treatment and management differ hence a timely and accurate diagnosis is paramount. Multiparameter comparison of the immunophenotype is possible by flow cytometry to characterize acute leukaemia. The limited availability of flow cytometry in the country and the cost of the service hinder most patients from accessing this service and thus a lot of the diagnosis of leukaemia is based on morphology alone which has several limitations including a higher risk of misdiagnosis which has an impact on treatment and outcomes. Using morphology alone, experienced morphologists are only 70􀂱80% correct in distinguishing ALL from AML. Whereas immunophenotyping using lineage specific flow cytometry panels is recommended to better characterise acute leukaemias, flow cytometry screening tubes have the potential to be a less costly alternative as they offer a marked improvement on the inadequacies of morphology whilst offering a diagnostic accuracy similar to lineage specific markers.

Objectives; The primary study objective was to determine the level of agreement between the screening tube diagnosis and the final diagnosis obtained after running the lineage specific panels at the Aga Khan University Hospital, Nairobi. The study also described the immunophenotypic characteristics of the discordant results.

Methods; This was an analytical cross-sectional study including patients of all ages suspected to have acute leukaemia and referred for flow cytometry analysis at the Aga Khan University Hospital Nairobi. The agreement between the screening tube diagnosis and the final diagnosis was determined using Co􀁋􀁈􀁑􀂶􀁖􀀃􀀮􀁄􀁓􀁓􀁄􀀃􀁖􀁗 v

Results; The overall agreement between the screening and final diagnosis after running the lineage specific panels was almost perfect with a kappa of 93.36% [p< 0.05, (95% CI 0.79-0.97). Misinterpretation of myeloperoxidase antibody in the screening tube contributed to 64% (9/14) of the discrepant results.

Conclusion; The study demonstrated that the acute leukaemia screening tube is almost as good as lineage specific panels in the diagnosis and classification of acute leukaemias. The screening tube can be an added diagnostic tool to complement morphology in resource-limited centres with the capacity to interpret flow cytometry analysis.

Download

Share

COinS