[Immunodiagnosis of rheumatoid arthritis author's transl)]

Rheumatoid arthritis (RA) presents a variety of immunological phenomena which can be of considerable diagnostic value. Of great significance is the determination of rheumatoid factors. Other autoantibodies are common but not specific for RA. Nevertheless the detection of such antibodies is beneficial for differential diagnostic considerations. Commonly demonstrated in rheumatoid arthritis are immune complexes which can be either soluble or within conclusions of circulating blood leucocytes or of synovial cells. Complement diminution can also be observed in RA, seldom in the serum, more often in synovial effusions. Like other humoral immune findings it lacks also disease specificity. A functional impairment of cellular immunity has also been postulated for rheumatoid arthritis, however the techniques for its demonstration are still cumbersome and cannot be easily used for routine diagnostic procedures. In conclusion, none of the immunological findings in RA is specific, however together with the anamnestic and clinical data it is possible to establish an exact diagnosis of this disease.