Cellular immune responses in vitro were studied in 24 patients on chronic hemodialysis and 16 healthy volunteers with normal kidney function. Patients on maintenance hemodialysis had lymphopenia with diminished numbers of both T4+ and T8+ T-lymphocytes. The T4/T8 ratios were within the normal range. Peripheral blood lymphocytes (PBL) showed a diminished proliferative response upon stimulation with concanavalin A, phytohemagglutinin and pokeweed mitogen. When cell surface antigens were used for stimulation (mixed lymphocyte culture) uremic lymphocytes also showed a lower proliferation rate. Although without statistical conformation, there was a tendency by uremic PBL to produce less IL-2 as compared to healthy controls. Moreover, in a PWM driven system, peripheral blood lymphocytes from uremics produced significantly less IgG than PBL from normals. These results support the notion that a profound defect in lymphocyte function accounts at least, in part, for the observed immunodeficiency of uremic patients.
A B S T R A C T The response of lymphocytes from young and old persons to phytohemagglutinin, pokeweed mitogen, or allogeneic lymphocytes has been measured. Lymphocytes from old persons incorporated significantly less tritiated thymidine as compared with lymphocytes from young persons when cultured with plant mitogens or allogeneic cells. The difference in observed lymphocyte reactivity could not be attributed to differences in culture conditions required for maximal transformation of lymphocytes from old or young subjects. The same percentage of thymus-derived and bone marrow-derived lymphocytes was found in the blood from old and young persons. The relationship of these findings to the decline of immunologic competence with age is discussed. INTRODUCTIONThe concept of immune surveillance suggests that the growth of neoplasms may reflect a failure of cell-mediated immunity. As the occurrence of cancer increases with age from an incidence of 13/100,000 persons at age 15 yr to 3,000/100,000 persons at age 90 (1), this hypothesis implies that cellular immune responses should decline with age. We have tested this prediction by comparing several parameters of immunological competence in persons less than 40 yr old and in persons over 75 yr old. The lymphocyte response to plant mitogens and allogeneic cells has been measured. Our results show that the response of lymphocytes from old persons to allogeneic lymphocytes and to plant mitogens is depressed compared with the response of lymphocytes from young persons.
The present knowledge of the inflammatory reaction occurring in situ during hepatitis B favors a T cell-dependent MHC-restricted immune response. However, the reports in the literature are primarily based on the application of monoclonal antibodies directed at different lymphocyte subsets which discern only lymphocytic phenotypes and do not reflect the actual situation adequately. Therefore, we investigated the liver biopsies of patients with hepatitis B (28 patients) and non-A, non-B (21 patients) by immunoelectron microscopy with monoclonal antibodies directed at lymphocyte subtypes (pan-B, pan-T, T8, T4 and NKH1) and at activation epitopes (IL-2 receptor, TA1 and T11/3) as well, in order to determine the phenotype in association with the activation status of the lymphocytes that are in close contact with hepatocytes; thus, establishing an effector-target cell relationship on the ultrastructural level. We were able to confirm the central role of T8 lymphocytes being the predominant type of lymphocytes in close contact with liver cells in the space of Disse. A certain percentage of these cells expressed "activation" markers as IL-2 receptor, TA1 and T11/3. In acute hepatitis, the NK lymphocytes made up a fifth of all lymphocytes, whereas their number dropped below 10% in the chronic stage. There was a vague correlation between the inflammatory activity of the disease and the expression of HLA antigens (both classes I and II) on inflammatory cells and also on hepatocytes. The results did not show significant differences between hepatitis B and non-A, non-B.(ABSTRACT TRUNCATED AT 250 WORDS)
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