Effects of Anti-salivary Gland Antibodies on Circulating and Tissue Lymphocytes: An Animal Experimental Study

ABSTRACT

In the present study, normal guinea pigs were used to investigate the possible pathogenic role of cell-mediated immunity in Sjogren's syndrome. The effects of anti-salivary gland antibodies on circulating lymphocytes, various organs including salivary glands, thymus and the reticuloendothelial system, and on delayed hypersensitivity were studied. Our study demonstrated that anti-salivary gland antibodies directly affected circulating lymphocytes. There was a 60-80% decrease in the lymphocyte count from the original level with a maximum effect at 5 hours after the introduction of the antibodies. When antibodies were injected repeatedly, the recovery to the pre-injection level of lymphocytes was delayed. We also found that antisalivary g1and antibodies were not organ-specific and were cross-reactive with various organs that are often involved in Sjogren's syndrome. Direct immunofluorescent study showed antibody deposits in the thymus-dependent areas of lymph nodes. These results suggest that antisalivary gland antibodies are lymphocytotoxic and have an anti-T cell property. The anti-salivary gland antibodies prepared in this experiment did not produce any pathological lesions such as those found in Sjogren's syndrome. The amount of antiserum or the period of administration might not have been long enough to produce pathological changes. Another possibility is that the anti-salivary gland antibodies might be species-specific. On the basis of these results, it appears that impaired cell-mediated immunity is not the primary pathogenic factor responsible for Sjogern's syndrome but rather that deranged immunity is secondary to the development of anti-salivary gland antibodies which occur in Sjogern's syndrome.