[Diagnostic value of synovial membrane immunofluorescence].

The immunofluorescent study of 93 synovial membranes of persons suffering from various types of arthropathy has shown that the only element sufficiently specific to have real diagnostic value is the presence of cells with a fluorescent cytoplasm. This appearance was in fact found in 63% of the cases of rheumatoid arthritis, irrespective of their being either seropositive or seronegative, in 69% of the cases of probable rheumatoid arthritis, in only 15% of the unclassified cases of arthritis, in 28% of the cases of various types of arthritis (20% with exclusion of a case of mixed connectivitis and of a case of Waldenström's macroglobulinemia with rheumatoid arthritis) and in 0% of the cases of mechanical arthropathy. The results of immunofluorescent examination compare favorably with those of standard histology: the classical histologic appearance of rheumatoid synovitis with a node-forming tendency of the infiltrate was observed in only 36% of the verified cases of rheumatoid arthritis, while immunofluorescence was positive in 63% of the cases in this group. In the category of unclassified arthritis, these percentages were comparable, viz. 19% and 20%, repectively. The presence of cells with fluorescent cytoplasm during immunofluorescent examination of the synovial membrane may be regarded as an additional criterion supporting the diagnosis of rheumatoid arthritis.