Effect of gammaglobulin injection on circulating immune complexes in various diseases.

Immune complexes (ICs) participate in the pathogenesis of various diseases and can be shown in 18% of all hospitalized patients (excluding those with infectious diseases) by means of a sensitive method such as the Raji-cell radioimmune assay. However, before this test can be applied to quantify disease activity in renal, connective tissue and neoplastic diseases, it must be recognized that febrile infections of the upper respiratory tract also induce ICs in 86% of all patients. The immune complexes containing microbial antigens can be reduced or removed by a single injection of human immunoglobulin. This is a simple method to distinguish between the immune complexes of different specifities. The resulting removal of some immune complexes may be the explanation for the claimed therapeutic effect of gammaglobulin injection in normogammaglobulinemic patients.