The consensus workshops for the detection of autoantibodies to intracellular antigens in rheumatic diseases.

In 1988 and in 1989 consensus workshops were organized in order to define the interlaboratory concordance in detecting autoantibody specificities in selected sera from patients with rheumatoid disorders and to determine the possible causes of discrepancies. In total 20 sera were tested for the presence of antibodies against nRNP, Sm, Ro (SS-A), La (SS-B), Scl-70, centromeric antigens, ribosomal RNP and Jo-1. The methods used for detection by the 28 European laboratories who participated included immunofluorescence, counter-immunoelectrophoresis, immunodiffusion, immunoblotting and ELISA. The results showed that only a combination of two or more techniques was able to detect all specificities with an adequate efficiency. Recommendations to improve the efficiency of autoantibody detection and to standardize laboratory protocols are given.