NOVEL ENZYME-LINKED IMMUNOSORBENT ASSAYS FOR THE DETECTION OF ANTI-FCGAMMA-RECEPTOR AUTOANTIBODIES

There is a substantial interest in the role of antineutrophil antibodi es since Fc gamma receptors (Fc gamma Rs) have been identified as the target for the majority of such autoantibodies. Antineutrophil antibod ies have long been detected by an indirect immunofluorescence techniqu e. Following optimization of the flow cytometric method of detection, we developed three enzyme-linked immunosorbent assays (ELISAs), each s pecific for autoantibodies against one of the three classes of human F c gamma R, Fc gamma RI and Fc gamma RII were purified from cultured ce lls, and Fc gamma RIII was produced as a recombinant molecule. These m ere then used as capture agents in the respective ELISAs. When applied in parallel to a sizeable group of patients with primary Sjogren's sy ndrome, both methods established that anti-Fc gamma R autoantibodies w ere heterogeneous. This finding indicates that different populations o f partly cross-reactive antibodies are detectable by these two methods .