Detection of circulating immune complexes by a Clq/protein A-ELISA during the preneoplastic stages of feline leukemia virus infection.

A microscale ELISA immune complex assay which utilized a solid phase C1q and a Protein A-peroxidase enzyme conjugate is described. This ELISA was used to detect and quantitate circulating immune complexes (CIC) during the initial feline leukemia virus infection. Significant increases in CIC were seen in the cats which were transiently infected at weeks three through eight after viral exposure. A persistent elevation in CIC was observed in the one cat which developed a persistent viremia. The addition of EDTA to the serum strongly interfered with this assay.