Enzyme immunoassay for the qualitative and quantitative determination of IgG antibodies against SS-A/Ro in human serum. SS-A/Ro-antibodies are directed against two distinct proteins, Ro52 and Ro60, which physiologically occur complexed with certain small hY-ribonucleic acids. These antibodies exhibit a high prevalence (> 70%) for the Sjögren-syndrome (SS), an inflammatory autoimmune disorder of the exocrine glands. They are also associated with systemic lupus erythematosus (SLE); especially with some of its variants (e.g. subacute cutane LE: prevalence about 80%). Sometimes, SS-A/Ro-antibodies cannot be detected by immunofluorescence assays (IFA) if the antigen is not sufficiently present in the substrate. Therefore, if SS or SLE is suspected despite negative IFA result, the appropriate enzyme-linked immunosorbent assay (ELISA) could be useful. The majority of SS-A/Ro-positive sera contain antibodies directed at both Ro60 and Ro52; hence, a differentiated analysis would not yield much diagnostic benefit. However, Ro52-specific antibodies seem to be closer related with SS and Ro60- antibodies with SLE.