Chronic arthritis of rabbits induced by mycoplasmas. II. Antibody response and the deposition of immune complexes.

Chronic mycoplasms-induced arthritis of rabbits was accompanied by a highly active humoral immune response. Peak antibody titers coincided with the "disappearance" of mycoplasmas from joint tissues at 7 weeks. High synovial fluid antibody titers and immunoglobulin-producing cells in frozen sections of synovial membrane suggested local antibody production. Persistence of granular deposits containing IgG and complement in synovium and cartilage may be a mechanism for continuing inflammation in the apparent absence of cultivable mycoplasmas.