Secretion of soluble chemotactic factors, including interleukin-6: a mechanism for the recruitment of CD8-positive T lymphocytes to human liver allografts during rejection.

In 35 patients receiving first liver transplants we assessed the chemotactic responsiveness of peripheral blood lymphocytes to bile, the subset composition of the responding population and the ability of peripheral blood lymphocytes to produce chemotactic factors. In 13 patients in whom acute rejection developed, lymphocyte chemotaxis in vitro was significantly greater in bile sampled 1 or 2 days after transplantation and before episodes of acute rejection than in bile sampled when rejection was clinically apparent or after steroid therapy during stable graft function. The chemotactic factors present showed preferential activity for CD8-positive T cells. Bile sampled during the same posttransplant periods from 11 patients who did not exhibit rejection showed significantly less chemotactic activity. In vitro cultured peripheral blood lymphocytes from patients in whom rejection developed produced lymphocyte chemotactic factors that induced a similar pattern of chemotactic responsiveness with preferential activity for CD8-positive T cells. Separate culture of purified CD4-positive and CD8-positive T cells obtained from patients in whom rejection developed showed that CD4-positive cells produced the factor(s). Analysis of the subset responses of normal peripheral blood lymphocytes to a variety of chemotactic cytokines showed interleukin-6 to have specificity similar to that observed with chemotactic bile, mixed peripheral blood lymphocyte culture supernatants and supernatants of CD4-positive T cells. Chemotactic activity was reduced by 45% to 90% in five chemotactic bile samples and three peripheral blood lymphocyte culture supernatants by treatment with affinity purified interleukin-6 monoclonal antibody.(ABSTRACT TRUNCATED AT 250 WORDS)