Circulating immune complexes in sickle cell anaemia.

Circulating immune complexes were investigated in sera of 100 patients with sickle cell anaemia (SCA) in different clinical stages, using inhibition of complement-dependent rosette formation (EAC rosette inhibition), anticomplementary activity, polyethylene glycol 6000 precipitation, immunoconglutinin titre, total haemolytic complement, C4 and C3d. A high positivity was observed in patients with hepatic crisis (75%) and cases with leg ulcers (43%) compared with painful crisis (12%) and asymptomatic (7%) patients. These results provide evidence for the presence of circulating immune complexes during leg ulcers and hepatic crisis in SCA.