The detection of circulating immune complexes in children with recurrent infections and their treatment with human immunoglobulins.

In a study of thirty-nine children with recurrent infections, circulating antigens, either free or in the form of immune complexes, were detected in thirty. The ability of sera to inhibit the agglutination of latex by rheumatoid factor or the C1q component of complement was used as a test for the presence of immune complexes. The children were treated by three injections of the same preparation of human immunoglobulin as that used for the serological tests, and a marked and sustained improvement in twenty-one patients was observed. In nineteen of these, circulating antigens reacted in vitro with antibodies in the immunoglobulin preparation, whereas of the eighteen children who did not improve with treatment, the sera of thirteen failed to react in vitro with the immunoglobulin preparation.