A cross-sectional study of the clinical manifestations of Sickles Cell Disease in Ghana, Nigeria and Tanzania and its association with foetal haemoglobin parameters

Background : Prevalence of Sickle Cell Disease (SCD) across African countries ranges between 1–3% and contributes up to 7-16% of under-five mortality. Nigeria, Ghana and Tanzania are among the top ten countries globally, with over 11,000 babies born with SCD annually. In order to bridge the gap in management and cognate research, the SickleInAfrica consortium was established in 2017 to facilitate collaboration among African nations in order to establish regionally relevant healthcare standards for SCD patients. This work utilised the SickleInAfrica platform to study haematological, clinical and genetic profiles of participants in the consortium. Methods : This was a cross-sectional omni-directional study involving three sites in Ghana, Nigeria and Tanzania.This study enrolled 290 individuals with SCD aged five years and above who were confirmed to have SCD at steady state and were hydroxyurea naïve. Clinical history was obtained using an interviewer administered questionnaire. Haematological parameters were determined by automated haematology analyzer while quantification of HbF and F cells was implemented by high performance liquid chromatography and flow cytometry, respectively. Age adjusted logistic regression was employed to assess the association of HbF with the clinical manifestations. Results : Participants were predominantly less than 18 years (63%) across the three countries. Most of the participants (across sites) had received blood transfusion in their lifetime. The most reported complication of SCD, requiring management in a hospital setting (in-patient or outpatient) was pain crises, ranging from 66-96% with the highest in Tanzania and lowest in Ghana. Overall, participants from Ghana had higher HbF levels(median = 8.20 with IQR= 4.80, 14.68, n = 68) compared with the level of HbF among participants from Tanzania (median = 4.45 with IQR= 2.33, 7.15, n = 92) and Nigeria (median = 4.30 with IQR= 2.60, 7.20, n = 7.20) and such difference was statistically significant, p < 0.001. Conclusion : This work highlights important differences and similarities across SCD populations in the three countries. This is important especially in development of interventions for patients with SCD in the light of personalised medicine. A larger dataset is required for further analysis and validation of the findings.