Abstract: | Using rabbit–anti-human T lymphocyte antisera in cytotoxic assays estimates of human T lymphocytes in normal or diseased lymphoid populations have been made. Lymphocytes from normal adult blood contained on the average 53% T cells, with slightly higher values for umbilical cord blood and lymph nodes. Close to 100% of human thymocytes were killed under the same conditions in one case analysed. Blood lymphocytes from Bruton or CVH patients could be shown to contain very few lymphocytes with high surface concentrations of immunoglobulin (with one exception) and a corresponding increase of T cells as tested by the cytotoxic assay. Patients with selective IgA deficiency had normal B and T lymphocyte levels whereas a patient with cryomacroglobulinaemia had close to 90% B lymphocytes and no detectable T lymphocytes. Patients with Hodgkin's disease could be shown to have a highly significant reduction in the number of T cells in the peripheral circulation. |