Platelet indices as accessible biomarkers for risk stratification in pediatric sickle cell disease: a Kenyan cohort study

Sickle cell disease is a significant health challenge in Kenya, often associated with complications that result in 50-90% mortality if undiagnosed. This necessitates accessible phenotype-based biomarkers for risk stratification in resource-limited settings that handle majority of the SCD cases in the Kenyan population. Platelet indices are potentially accessible indicators of thrombo-inflammation but their variations across Kenya’s clinical phenotypes are understudied. This cross-sectional observational study, involving 104 children aged 1-14 years stratified into four groups, was carried out at Kenyatta National Hospital to evaluate the clinical significance of altered platelet indices and establish their utility in screening and risk stratification. Platelet indices were derived from full hemograms of venous blood samples from the consenting participants, with platelet-derived ratios subsequently calculated. Data were analyzed using Kruskal-Wallis H-tests, post hoc Mann-Whitney U tests, and pairwise ROC curves to establish the diagnostic utility of the platelet indices, platelet-derived ratios, and neutrophil count in pediatric SCD. The tests revealed significant differences in PLT, MPV, PCT and PNR across SCD phenotypes. Elevated MPV and Neutrophils with reduced PNR observed in vaso-occlusive crisis and ischemic stroke, with variations in MPV:PLT also noted in complications. Contrary to the global trends, however, there were no significant age-related differences in PLT across the cohort, suggesting influence of environmental factors and early asplenia. There were distinct hematological signatures across SCD clinical phenotypes, highlighting the potential of MPV, PNR, MPV:PLT, and neutrophil count as potentially accessible low-cost tools for risk stratification in rural healthcare facilities with limited access to advanced imaging.