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

Abstract

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.The degree of lattice formation of immune complexes is dependent on the properties of both the antigen and the antibody, the size of the antigen, the number and type of antigenic determinants, the class of the antibody, and the avidity of each antibody for its corresponding antigen (1,2).In 1975, Miller and Nussenzweig demonstrated that antigen-antibody aggregates formed in vitro can be solubilized by addition of fresh serum. This phenome-

Inhibitory effect of igm rheumatoid factor on immune complex solubilization capacity and inhibition of immune precipitation

“…Preliminary studies have shown that impairment of these functions correlated equally well with disease activity and with complement component levels in patients with systemic lupus erythematosus, vasculitis, or post-streptocaccal glomerulonephritis (7)(8)(9).…”

Increased solubilization of immune complexes by the sera from ptients with Behcet's disease.

“…A decrease in the capacity to solubilize complexes observed in sera from patients with systemic lupus erythematosus (Aguado et al 1981) might be additively contributing to the immune complex deposition in various tissues in this disease (Kofer et al 1967;Miescher et al 1976). …”

Complement-Mediated Solubilization of Immune Complexes and Their Interaction with Complement C3 Receptors

“…Studies of CMS in sera from patients with IC disease have mainly focused upon SLE [2,5,6,9,65,68], In these reports the CMS capacity was found reduced below the nor mal reference range in a large fraction of these sera ( fig. 2).…”

“…These data indicate that no single factor is responsible for the diminished capacity of SLE sera to solubilize IC, but low concentrations of one or more factors in the classical or alternative pathway may contrib ute to the reduced CMS. Furthermore, there appears to be no simple association between solubilization capacity and CIC levels in SLE patients [2,7,68].…”