Erythrocyte Deformability and Membrane Protein Composition in Sickle Cell Disease Patients on Hydroxyurea Therapy in Abuja, North Central Nigeria

This study evaluates erythrocyte deformability and red cell membrane protein composition in sickle cell disease (HbSS) patients receiving hydroxyurea therapy compared to untreated HbSS patients and HbAA controls at the National Hospital Abuja, North Central Nigeria. Hydroxyurea improves clinical outcomes in SCD partly through effects on HbF induction, but its impact on erythrocyte biophysical properties and membrane integrity in Nigerian patients has not been analytically characterised. An analytical cross-sectional study recruited 50 HbSS patients on hydroxyurea (at least 12 months therapy), 50 untreated HbSS patients, and 50 HbAA controls. Erythrocyte deformability was assessed by laser-diffraction ektacytometry. Membrane protein composition was analysed by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) with densitometry. Oxidative markers including malondialdehyde (MDA) and superoxide dismutase (SOD) were measured. HbF percentage was determined by HPLC. HbSS patients on hydroxyurea showed significantly greater erythrocyte deformability than untreated HbSS patients at all osmotic gradients tested, approaching but not reaching HbAA levels. Band 3 protein band intensity was significantly restored toward normal in hydroxyurea-treated cells compared to untreated HbSS. Oxidative stress markers were intermediate in the hydroxyurea group, significantly lower than untreated SCD but above controls. HbF percentage correlated positively with ektacytometric deformability index. These findings provide mechanistic evidence for hydroxyurea's beneficial haemobiophysical effects in the Nigerian SCD population. Keywords: erythrocyte deformability, hydroxyurea, sickle cell disease, membrane proteins, Abuja.