Effect of inherited deficiency of the fifth component of complement on arthritis induced in mice by Mycoplasma pulmonis.

Mycoplasma pulmonis inoculated parenterally into mice deficient in the fifth component of complement (C5) caused a chronic arthritis of significantly greater magnitude than in immunologically normal mice. During the chronic phase of arthritis M pulmonis organisms were isolated from the joints and organs of C5 deficient mice more frequently and in larger numbers than from immunologically normal mice. The implications of the results are discussed in relation to the pathogenesis of M pulmonis induced arthritis and human connective tissue diseases.