Abstract
Forty-three patients with homozygous sickle cell disease (haemoglobin SS), 24 heterozygous (AS) subjects and 24 controls (AA) from Sudan were investigated by haemolytic activation for complement function via the classical and the alternative pathways, respectively, and by determination of the plasma levels of C3, C4 and factor B as well as of immunoglobulins IgG, IgA and IgM. The study failed to reveal any direct involvement of the complement system in sickle cell disease and nor was any alteration of the immunoglobulin levels registered as a possible cause of increased susceptibility to infections in patients with homozygous sickle cell anaemia.