Lacrimal immunoglobulins in rheumatoid arthritis patients with or without Sjogren's syndrome

The aim of the present study was to analyse immunoglobulin G, A, and M levels in tears of patients with rheumatoid arthritis with or without keratoconjunctivitis sicca (KS) which define Sjogren's syndrome (SS). Tears were collected from the lower cul-de-sac by capillarity (100-300 μl). Tear IgG, IgA and IgM levels were determined by radial immunodiffusion. Samples diluted 1:10 were used for IgA and IgG and non-diluted ones for IgM. Fifty- three patients with rheumatoid arthritis and 30 healthy control subjects were studied. In all individuals IgA predominated in tears, IgG levels were low but with a very wide range and IgM was present in very low concentrations. The IgG concentration in tears showed statistically significant differences between the control group and that of rheumatoid arthritis and KS. IgG in tears correlated positively with the rose bengal test (r=0.2848, p<0.05) and negatively with the Schirmer test (r=-0.3042, p<0.05). Tear IgG measurement might provide a marker for eye involvement in patients with rheumatoid arthritis and KS which define SS.