USR PUBLISHER

Background: Chronic myeloid leukaemia (CML) is a BCR::ABL1-positive myeloproliferative neoplasm in which clonal myeloid expansion and its treatment may disturb normal erythropoiesis. Routine erythrocyte measurements are widely available, but their pattern among patients receiving care in south-eastern Nigeria has not been adequately described. Objective: To compare packed cell volume (PCV), red blood cell (RBC) count, mean cell volume (MCV), mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC) and red cell distribution width (RDW) between adults with CML and apparently healthy controls in Owerri, and to examine variation by age and sex among the patients. Methods: This comparative cross-sectional study recruited 30 adults with CML and 30 age-matched apparently healthy controls at Imo State Specialist Hospital, Owerri, from February to April 2024. Five milliliters of venous blood was collected into ethylenediaminetetraacetic acid tubes. The haematological parameters were measured using a Mindray BC-5180 haematology analyser. Data were summarised as mean ± standard deviation and compared using independent-samples t tests or one-way analysis of variance, with statistical significance set at p<0.05. Results: Participants with CML had lower PCV (24.60±4.50% versus 37.50±3.22%; p<0.001) and RBC count (2.54±0.43 versus 3.82±0.64×10¹²/L; p<0.001) than controls. MCV (86.13±10.56 versus 73.10±16.00 fL), MCH (29.73±2.88 versus 25.77±4.49 pg) and RDW (14.70±2.74 versus 12.10±1.58%) were higher in the CML group (all p<0.001), whereas MCHC did not differ (34.47±1.74 versus 34.37±2.75 g/dL; p=0.884). No sex-related difference was detected among patients. MCV varied across age groups (p=0.024), but the other indices did not. Conclusion: Adults with CML in this setting showed a marked reduction in red cell mass accompanied by greater erythrocyte size and size heterogeneity. Routine interpretation of the complete blood count should therefore extend beyond haemoglobin or PCV alone. Because disease phase, treatment exposure, nutritional status and molecular response were not measured, the findings are descriptive and require confirmation in larger longitudinal studies.