A COMPARISON OF IMMUNOGLOBULIN-G CONTAINING HIGH-MOLECULAR-WEIGHT COMPLEXES ISOLATED FROM CHILDREN WITH JUVENILE RHEUMATOID-ARTHRITIS AND CONGENITAL HUMAN-IMMUNODEFICIENCY-VIRUS INFECTION

Circulating immune complexes have been described in both juvenile rheu matoid arthritis and in AIDS. We isolated high-molecular-weight comple xes from plasma of children with juvenile rheumatoid arthritis and con genital human immunodeficiency virus infection by sequential gel filtr ation followed by affinity chromatography on protein A-Sepharose. We d emonstrate that 1) mixed IgG-, IgM-, and IgA-bearing immune complexes can be found in both juvenile rheumatoid arthritis and congenital huma n immunodeficiency virus infection and 2) complexes isolated via affin ity chromatography on protein A-Sepharose do not have detectable C4 bu t activate the classic complement pathway in vitro.