Abstract
The relationship between clinical, laboratory or immunological findings and extra-articular features were studied in 131 rheumatoid arthritis (RA) patients.
(1) The group without extra-articular complications (18 cases, 13.7%); The mean age was more younger, and the mean duration of RA was more shorter in this group. Immunologically, the serum concentrations of complements were highest, compared with those of other groups.
(2) The group of malignant RA (MRA) or with interstitial pneumonia (22 cases, 16.8%); The serum concentrations of C-reactive protein (CRP) and rheumatoid factors (RF) were significantly higher in this group than those of patients without complications.
(3) The group with amyloidosis (17 cases, 13.0%); They were also characterized by increased level of CRP. However, the serum IgG concentration was significantly lower in these cases. Proteinuria and impairment of renal function were observed in 13 (76.5%) and 12 patients (70.6%), respectively.
(4) The group complicated with other collagen vascular diseases such as systemic lupus erythematosus or mixed connective tissue disease (18 cases, 13.7%); This group showed hypocomplementemia and hypergammaglobulinemia frequently.
(5) The group with histologically-proved renal lesions (30 cases, 22.9%); Hematuria was found in 18 patients (60%), proteinuria in 12 (40%), and decreased renal function in 6 (20%). Laboratory examinations revealed lower concentrations of CRP and RF, compared with those of other groups. No significant difference was observed in serum concentrations of immunoglobulin and RF among various nephropathies. These results suggests that the inflammatory and immunological processes may not have significant effects on the development of renal lesions in RA patients.
