Proportional and functional studies of the infiltrating lymphocytes in the parotid gland of Sjögren's syndrome associated with rheumatoid arthritis.

ABSTRACT

Lymphocyte subpopulations and functions were examined in the salivary (parotid) gland lymphocytes (SGL) obtained as a cell suspension from a patient with Sjögren's syndrome associated with rheumatoid arthritis, in comparison with peripheral blood lymphocytes (PBL). Serial studies on the lymphocyte subsets in PBL using monoclonal antibodies to helper or suppressor T cell subsets (OKT4 or OKT8) demonstrated a decreased proportion of the OKT8 subset (OKT4/OKT8 ratio 7.1-34.0). Major infiltrating cells in the gland were surface immunoglobulin-bearing B cells, and 23-35% of the SGL were T cells by both the E-rosetting method and OKT3-monoclonal antibody reactivity. Moreover, OKT4/OKT8 ratios were definitely lower in the SGL (1.0 and 1.7) than those in the PBL of the patient. Mitogen-induced lymphocyte proliferative responses of the SGL were markedly diminished, although the possible participation of defective macrophages was considered. The autologous mixed lymphocyte reaction was low in both PBL and SGL. PBL of the patient showed normal proliferative responses to mitogens except for PWM stimulation. Suppressor effects of the SGL for the proliferative responses of autologous and allogeneic PBL were demonstrated. Con A-induced suppressor function was inducible in the SGL, whereas that function could not be demonstrated in the patient's PBL.