[Pteridine secretion as a marker for the proliferation of alloantigen-induced lymphocytes (author's transl)].

Pteridine levels from supernatants of mixed lymphocyte cultures and from urinary samples of allogeneic kidney transplant recipients were measured by high-pressure liquid chromatography. Marked proliferation of alloreactive lymphocytes was paralleled by an increased release of pteridines. In human allograft recipients rejection episodes were preceded at least 1-2 days by increased urinary neopterin levels. Thus, the urinary neopterin estimation is useful in the early detection of immunological rejections.