Serologic Findings in Rheumatoid Arthritis as an Immunological Approach to Aging
As an autoimmune disease primarily of aged individuals rheumatoid arthritis can provide insights into the mechanism of aging. The specific aim of this investigation was to determine whether rheumatoid synovium contained antigenic moietes different from those of normal synovia using serologic analysis. Crude human synovium in 1 gram quantities from rheumatoid (RA) and non-rheumatoid (NRA) patients was prepared by either sonication to release cell surface antigens (30 sec/20 w) or incubation in RPMI 1640 for 1 wk at 37 ~ in 5% CO 2, Supernatant solutions were subsequently collected to obtain either a sonicated (S) or medium extract (ME) for testing serological reactivity with anti-immunoglobulin (Ig) and anti-complement (C3) sera by microgel immunodiffusion. In some experiments synovium from RA and NRA served as target tissues for acid phosphatase (AP) activity. IgA activity was detected only in S and ME type extracts from RA patients and in one patient with synovitis, whereas extracts from other NRA and normal synovia did not contain detectable IgA. Synovium from an RA patient serologically positive for IgA; C3 was also markedly increased in AP, whereas NRA synovium lacked AP as well as detectable IgA; C3activity.
These results suggest that the alternate pathway of C 3 activation triggering chemotactic factors can attract leukocytes into the synovium which release lysosomal enzymes possibly involved in some connective tissue degeneration of aging.
& Bigley, N. J.
(1978). Serologic Findings in Rheumatoid Arthritis as an Immunological Approach to Aging. AGE, 1 (1), 32-38.