No abstract

Six patients with Rheumatoid Arthritis (RA) have been treated with lymphocytapheresis after their disease proved unresponsive to conventional therapy. Clinical improvement, measured evaluating articular swelling, morning stiffness, and muscle weakness, was observed in four of the six patients. From the cellular point of view lymphocytapheresis induced (1) T cell depletion without modification of lymphocyte subsets in the peripheral blood, (2) improvement of lymphocyte responsiveness to lectins, autoantigens and alloantigens. All together these data suggest that therapeutic leukapheresis modifies the immune responsiveness in humans, possibly facilitating the process of cell to cell cooperation.

We studied the phenotype of T-lymphocytes isolated from 18 patients with head and neck cancer, their capacity to express Ia antigens upon activation by lectins in vitro, their capacity to function either as responder or stimulator cells in autologous mixed lymphocyte reaction, and their capacity to cooperate with the normal adherent suppressor cells (NASC). The T-lymphocytes isolated from these patients have several functional defects including an impaired capacity to activate allogeneic lymphocytes in mixed lymphocyte reactions (MLRs), a lack of a proliferative capacity in autologous MLRs, an impaired sensitivity to inhibition by NASC, and an impaired capacity to express Ia antigens upon activation by mitogens in vitro. These data indicate that, in patients with head and neck cancer, immune function is characterized by a defect in T-lymphocytes functions which concerns the process of cell to cell cooperation.

A reduced percentage of T cells isolated from mediastinal lymph nodes and peripheral blood of patients with lung carcinoma acquired HLA Class II antigens following in vitro stimulation with PHA. Furthermore T cells were functionally abnormal in autologous and allogeneic mixed lymphocyte reactions (MLR). The immunoregulatory properties of HLA Class II antigens and autologous MLRs suggest that these abnormalities may affect the interaction of the host's immune system with tumor cells.

The effect of normal adherent suppressor cells on the blastogenesis of human T lymphocytes in the mixed lymphocyte reaction (MLR) was studied in both allogeneic and autologous combinations. Non-T cells and Ia+ T lymphocytes were used as stimulator cells in both allogeneic and autologous MLR. The addition of adherent cells to the stimulators inhibited blastogenesis of T lymphocytes in both types of MLR when the stimulator population was made up of non-T lymphocytes but did not interfere with blastogenesis when Ia+ T lymphocytes were used as stimulator cells. The present data indicate that the T lymphocytes able to respond to Ia+ T cells (in the MLR, autologous or allogeneic) may be different from those which respond to non-T lymphocytes or may be less sensitive to the regulatory function of normal adherent cells.