Antigen retention in joint tissues in antigen-induced synovitis

Abstract

In the rabbit model of antigen-induced arthritis the duration and mechanism of antigen retention were investigated. The tissue half-life of retained antigen in descending order was meniscus (141 days), articular cartilage (31 days), ligaments (17 days), synovium (8 days) and synovial fluid (4 days). The retention of antigen in collagenous tissue was very firm. Perturbant solutions were used to study the binding of antigen to menisci, and only 6 M guanidine was effective in removing the antigen. The role of specific antibody was investigated. Antibody was bound to normal menisci, but the Fc portion of the molecule was not critical to the uptake of antibody by collagenous tissue. Finally, the interaction of antigen, antibody, and collagenous tissue was studied. Preformed soluble immune complexes produced three times the retention of antigen alone. Sequential administration of antibody and antigen yielded fifteen times the retention of antigen in the normal rabbit. Therefore, antigen retention in collagenous tissue was due to immune complex formation with specific antibody within the cartilage matrix.