Clinical and immunological comparison of patients with RA with and without extra-articular features(Rheumatoid Arthritis : Recent Topics)

Comparative studies of clinical, laboratory and immunological findings were performed for 134 rheumatoid arthritis (RA) patients in relation to several extra-articular features. There were 22 cases of malignant RA (MRA) or RA with interstitial pneumonia. The titers of rheumatoid factor (RF) determined by enzyme linked immunosorbent assay were significantly higher in sera from these RA patients than in sera from RA patients without extra-articular features. Seventeen RA patients were complicated by secondary amyloidosis. In this group, proteinuria and impairment of renal function were observed frequently. Concurrence of RA and other collagen vascular diseases were observed in 18 patients. In this group, hypocomplimentemia and hypergammaglobulinemia were observed frequently. RA with biopsy-proven renal disease were observed in 30 patients. Laboratory results of this group revealed characteristic findings, namely lower concentrations of CRP and RF compared with those of other groups. These results suggest that inflammatory and immunological mechanisms may not have any major role in the pathogenesis of nephropathy in patients with RA, contrary to their role in other extra-articular manifestations experienced in MRA patients