International Journal of Research and Reports in Hematology

Aims: To determine serum vitamin B12 and creatine kinase levels and to establish their relationships with selected haematological parameters among patients with sickle cell anaemia attending a tertiary hospital in southwestern Nigeria.

Study Design: A cross-sectional comparative study.

Place and Duration of Study: Department of Haematology Laboratory, University College Hospital, Ibadan, Oyo State, Nigeria, as part of a postgraduate research programme completed from July 2025 to July 2026.

Methodology: Two hundred and fifty participants were enrolled, comprising 150 confirmed HbSS sickle cell patients in steady state and 100 apparently healthy HbAA controls. Ten millilitres of venous blood was collected from each participant. Full blood count parameters were determined on an automated haematology analyser, serum vitamin B12 was quantified by enzyme-linked immunosorbent assay, and serum creatine kinase activity was measured on an automated chemistry analyser. Group comparisons were made using the independent-samples t-test and one-way analysis of variance, and relationships among variables were examined using Pearson correlation, with significance taken at p < 0.05.

Results: Packed cell volume (19.84 ± 4.52% versus 38.74 ± 2.45%), haemoglobin (6.52 ± 1.48 g/dL versus 14.72 ± 14.18 g/dL) and total white blood cell count (7,736 ± 3,406 versus 6,232 ± 1,744 cells/µL) differed significantly between patients and controls (p < 0.001 for each). Platelet count and the differential leukocyte counts were similar between the two groups (p > 0.05). Mean serum vitamin B12 (342.25 ± 463.36 pg/mL versus 445.60 ± 551.20 pg/mL, p = 0.258) and creatine kinase (169.32 ± 7.04 U/L versus 171.14 ± 6.41 U/L, p = 0.116) were comparable between the groups. Within the patient group, vitamin B12 correlated positively with lymphocyte percentage (r = 0.203, p = 0.042) and negatively with neutrophil percentage (r = -0.207, p = 0.039), while creatine kinase correlated negatively with basophil percentage (r = -0.261, p = 0.009). When patients were stratified into tertiles of vitamin B12 and creatine kinase, both markers showed graded, statistically significant associations with packed cell volume, haemoglobin, total white cell count, platelet count and differential leukocyte proportions (p < 0.05 for all).

Conclusion: Although mean serum vitamin B12 and creatine kinase levels were not significantly different between sickle cell patients and controls in this cohort, both markers showed consistent, graded relationships with haematological indices among patients, particularly with the immune cell components of the full blood count. Routine assessment of vitamin B12 and creatine kinase alongside the standard full blood count may support a more comprehensive evaluation of patients with sickle cell disease.