Complement Levels in Nigeria Patients with Sickle Cell Anaemia in the Asymptomatic State

Significantly low serum levels of complement components have been reported in patients with Sickle cell anaemia (SCA) which may result in a high susceptibility to infections. However some studies have reported a normal or high complement level. The aim of our study was to assess some haematological parameters and Complement levels in adult patients with steady state SCA in Zaria, North western Nigeria. This will serve as a guide towards infection surveillance in the quest to reduce significant morbidity and mortality in our setting.

A cross sectional study of 40 patients with SCA in steady state and 40 healthy (non-matched) non-SCA controls at the Haematology clinic of Ahmadu Bello University Teaching Hospital Zaria, was carried out over a 6 month period in 2016. Institutional ethical approval and informed written consentwere obtained. Venous blood was analyzed for haematological parameters by an automated method and complement levels; alternative pathway was assessed by measuring C3, classical pathway by C4 and Terminal pathways by C5 levels using ELISA technique. Data was analyzed with statistical package for social science(SPSS) software version 20.0(2001) and a p value of ≤ 0.05 was considered significant.

The age range of patients with SCA and controls were 18 to 46years and 18 to 48years respectively and these were not significantly different p > 0.05. The median levels of C3 (245μg/ml), C4 (245μg/ml) and C5 (40μg/ml) were within normal range in the study subjects but significantly higher (p < 0.05), than those of the controls C3 (165μg/ml), C4 (125μg/ml) and C5(35μg/ml). Haematological parameters showed no correlation with the levels of Complement components studied.

Although Complement components C3, C4, and C5 levels in patients with SCA are significantly high, the infectious susceptibility may be due to other immunological abnormalities.