Identification of collagen-anticollagen immune complexes by collagenase-digestion

A method for the detection of collagen-anti-collagen immune complexes using collagenase of bacterial origin is described. Anti-collagen-titers are determined in passive haemagglutination before and after collagenase digestion of samples containing preformed immune complexes. An increase in anti-collagen titers following the enzymatic treatment suggests the presence of collagen-anti-collagen immune complexes. Both solbule and carrier-bound collagenase proved to be equally effective in the digestion of complex-bound collagen, if in vitro prepared collagen-anti-collagen complexes were investigated. Original titers of partially or totally inhibited antisera to collagen could be completely restored by this method.