Interferon production from peripheral blood, synovial fluid, and synovial tissue lymphocytes in patients with rheumatoid arthritis and ankylosing spondylitis.

A previous study demonstrated that interferon was present in the serum of 30% of the patients with systemic lupus erythematosus (SLE), which was significantly higher than the 4.5% found in normal controls. We also recently reported that interferon production was deficient from SLE mononuclear cells, which has been attributed to immunodeficiency of the lymphocytes. In this study, interferon measurement included lymphocytes obtained from peripheral blood (PB), synovial fluid (SF) and synovial tissue (ST) in patients with rheumatoid arthritis (RA) and ankylosing spondylitis (AS). PB from normal subjects (NS) was used as a control. The results showed with PHA stimulation, that the interferon level in PBL (L = lymphocyte) in NS (70.0 +/- 67.5) was significantly higher when compared with PBL in RA (27.9 +/- 21.6). However, there was no difference between PBL in NS and AS. With ConA stimulation, the interferon level was significantly higher in the PBL of NS (130 +/- 59) and as compared with the PBL in RA (83.6 +/- 53.5). The SFL in RA (67.8 +/- 31.1) and the STL in RA (77.2 +/- 93.2) were also significantly different. It is concluded that interferon production was deficient not only in PBL in RA, but also in SF and STL in RA. The reduced interferon production from PB, SF and ST lymphocytes in RA patients may be due to previous release or immunodeficiency. Lymphocyte interferon production was normal in AS, which suggests that the lymphocyte abnormality between RA and AS may be different.