Decreased capacity to solubilize immune complexes in sera from patients with systemic lupus erythematosus.

The capacity to solubilize immune complexes formed in vitro is significantly decreased in patients with systemic lupus erythematosus (SLE). This complement function correlates significantly with serum C3 levels and inversely with the presence of circulating immune complexes. Clinically, patients with a decreased capacity, to solubilize complexes show a worse evolution and an increased incidence of renal involvement. In conclusion, the impaired solubilization capacity, related to low complement activity, which is observed in patients with SLE may favor the persistence of immune complexes in tissues.