Circulating immune complexes and complement-fixing antibodies in patients with varicella-zoster infection. Relationship to début of the disease.
Serum samples from 32 varicella-zoster (VZ)-infected patients were examined for circulating immune complexes (IC) within 1 1/2 week after début of the skin rash as well as during the following 5 weeks. Three test systems were used: a complement consumption (CC) assay, a C1q solid phase (CU1-SP) assay and a polyclonal rheumatoid factor-binding (pRF-I) assay. The CC and pRF-I assays were the most effective in detecting large IgG aggregates of IC, while aggregates of intermediate and small size were more easily demonstrated in the C1q-SP assay. IC were demonstrated in at least 2 assays simultaneously in 16 patients. Four of these patients were IC-positive in both observation periods, while 11 converted to IC-positive in the second observation interval. In 3 patients circulating IC were demonstrable as late as 8--10 weeks after the appearance of the skin rash. Maximal levels of complement-fixing antibodies to VZ antigens were observed 2 to 5 weeks after the appearance of the rash.