Soluble interleukin 2 receptors in patients with malignant lymphoma.

We performed a retrospective analysis of serum interleukin 2 receptor (IL-2R) levels in a group of 35 patients with malignant lymphoma (ML; 13 T cell and 22 B cell) using a new enzyme immunoassay. Our objectives were to determine if elevated levels of soluble IL-2R occur in patients with active ML, whether serum IL-2R levels are prognostic, and whether prospective studies are warranted. Our preliminary data indicate that serum IL-2R levels correlate with disease activity and size of tumor, but not with grade or stage of the tumor. Five-year actuarial survival was 20% for patients with IL-2R levels greater than 1000 U/mL at any time during their course and 86% for patients who did not exceed that threshold. Furthermore, patients with IL-2R levels lower than 1000 U/mL were more likely to achieve a complete remission. Serum lactate dehydrogenase and uric acid levels did not show significant correlation with disease activity or prognosis. We conclude that serum IL-2R levels may have clinical and prognostic significance in patients with ML and that prospective studies are indicated.