A probable explanation for mild extra-articular manifestations in Indian patients of rheumatoid arthritis: a preliminary study.

One hundred four Rheumatoid factor (RF) positive Rheumatoid Arthritis (RA) patients fulfilling ARA criteria were screened for extraarticular manifestations. Rheumatoid nodules were present in 2.8% cases. Other extraarticular manifestations such as pulmonary, cardiac, occular, renal or GI involvement were absent in these cases. However, circulating immune complexes (CICs) were highly significantly raised in all the RA patients (P < 0.001). From amongst these cases a limited number (8 cases) have been subjected to qualitative and quantitative analysis of CICs to look for whether there could be any relationship between these and mild extraarticular manifestations that were being noticed in our groups of patients. Finding showed IgG-IgG CICs in five, IgG-IgM in two and IgG-IgA in one case. Quantitative analysis revealed mean IgG 4.97 +/- 1.7 IU/ml, IgM 14.58 +/- 5.53 IU/ml and IgA 5.08 +/- 1.53 IU/ml on LD Solugen plates. Serum concentration of C3 was not reduced (94.1 +/- 8.9 mg/dl). Low IgM contents of CICs and no reduction in complement level is the likely explanation for less severe inflammatory manifestations seen in our study. The conclusion and findings have been discussed in the light of observation reported by the Western workers.