QUANTITATIVE HISTOPATHOLOGIC DISCRIMINATION OF RHEUMATIC DISORDERS USING NUCLEAR MEASUREMENTS OF SYNOVIOCYTES

OBJECTIVE: To use several nuclear quantitative estimators of synoviocy tes and advanced statistical tests to discriminate between rheumatic d isorders with the purpose of providing an objective histopathologic di fferentiation and to illustrate the difficulty of establishing the imp lications of the vague diagnosis of chronic nonspecific synovitis. STU DY DESIGN: Synovial histologic material from 48 patients, including a control group and those diagnosed with osteoarthritis, rheumatoid arth ritis and chronic nonspecific synovitis, was analyzed. Both morphometr ic and stereologic nuclear measurements were assessed in each case, an d several stepwise discriminant analyses were performed to obtain line ar discriminant functions. RESULTS: Differences in the nuclear size pa rameters were found between rheumatoid arthritis and the normal and os teoarthritis groups and between normal and chronic nonspecific synovit is. The volume-weighted mean nuclear volume was the most significant p arameter. No differences were demonstrated between osteoarthritis and normal and chronic nonspecific synovitis or between rheumatoid arthrit is and chronic nonspecific synovitis except for nuclear volume. Using stepwise discriminant analysis, 94% of the cases were correctly classi fied when differentiating the normal, osteoarthritis and rheumatoid ar thritis groups. The overall accuracy of diagnosis decreased to 83% whe n chronic nonspecific synovitis samples were included. The misclassifi ed samples were related mainly to normal cases and to osteoarthritis a nd chronic nonspecific synovitis cases. CONCLUSION: This study emphasi zed that nuclear quantitative features of synoviocytes may be useful i n differentiating rheumatic disorders objectively, especially in combi nation with discriminant analysis. Thus, nuclear changes in the synovi um in chronic nonspecific synovitis show a closer similarity to normal and oteoarthritis than to rheumatoid arthritis.