Cutaneous delayed hypersensitivity, T cell subsets, and IL-2 secretion in patients with peripheral vascular disease

To determine whether anergy in patients with peripheral vascular disease is related to an abnormality of their T cells, the distribution of T-cell subsets and monocytes in peripheral blood was studied in relation to the delayed hypersensitivity response following the intradermal injection of 7 recall antigens. Positive correlation coefficients were observed between either the sum of the induration at 48 hr or the number of antigens giving a positive response and the percentage of total T cells (OKT 3) and helper T cells (OKT 4). The percentages of suppressor/cytotoxic T cells (OKT 8) and monocytes (OKM 1) showed no correlation with skin reactivity to the recall antigens. In vitro secretion of IL-2 by purified T cells was similar in anergic patients and in patients with normal delayed hypersensitivity responses. Addition of IL-2 to unstimulated T cells or T cells stimulated in vitro with either tetanus toxoid or PPD sometimes potentiated incorporation of 3H-thymidine into the cells after 6 days of culture.