[Anti-immunoglobulins in multiple myeloma and benign monoclonal hyperglobulinemia].

Sera from 50 healthy adults, from 21 patients with multiple myeloma (MM) and from 11 patients with benign monoclonal hyperglobulinaemia (BMH) and from 28 patients with sarcoidosis were examined for the presence of anti-IgG-activity by passive haemagglutination technique. 62% of healthy adults (titre less than 2) and all of the sera from patients with MM and BMH (titres 32-512) as well as 42% of the sera from sarcoidosis patients were found to be anti-IgG positive. The anti-IgG positive sera showed also anti-(Fab)2-activity (with the exeption of 2 sera from sarcoidosis patients). No significant differences could be found between anti-Ig activity in sera from MM patients with BMH. There was also seen no correlation of anti-Ig with the clinical course of the disease. After column chromatography we could detect the partially simultaneous presence of anti-Ig with anti-Fc-specificity (MW ca. 900,000) and with (Fab)2-specificity (MW 150,000 or less than 90,000). Antibody dependent cytotoxicity (using melanoma cell lines as targets) was significantly inhibited by the isolated anti-Ig-fractions with low molecular sizes (MW less than 90,000). From these results it seems possible that anti-immunoglobulins may play a role in the clinical course of the disease.