Arthritis in mice due to infection with Mycoplasma pulmonis. II. Serological and histological features.

Histological and serological data were obtained from a group of 160 mice given intravenous inoculations of 3.5 X 10(7) colony-forming units of Mycoplasma pulmonis and studied for 46 weeks. The basic pathology was that of an initial acute inflammatory response within the joint and periarticular tissues, slowly changing to a chronic inflammatory response seen predominantly in subsynovial areas with marked synovial proliferation. Occasional lymphoid follicles and plasma cells were seen in the subsynovial spaces. Titers of antibody to M. pulmonis were determined by both metabolic inhibition and indirect hemagglutination techniques. By the metabolic inhibition method, titers were highest between two and 22 weeks, and by indirect hemagglutination between four and 42 weeks. Antibodies to synovial antigens were present between nine and 26 weeks as determined by indirect hemagglunination. Serologic cross-reactions were found between M. pulmonis and normal mouse synovium in sera from infected mice and, by indirect hemagglutination, metabolic inhibition, and immunodiffusion techniques, in sera of rabbits or mice immunized with either M. pulmonis or mouse synovium.