[Clinical relevance of circulating immune complexes in patients with systemic lupus erythematosus and chronic polyarthritis].

Using a solid phase C1q assay, circulating immune complexes (IC) were detected in 15 of 55 patients with rheumatoid arthritis (RA) and 6 of 14 patients with systemic lupus erythematosus (SLE). In contrast to RA, presence of IC correlated to clinical disease activity in SLE patients. Preliminary short term follow up studies revealed additional differences between RA and SLE: whereas persistence of IC was noted in the patients with SLE, rapid changes of IC levels were observed in RA.