A comparative study of intravenous versus intralymphatic interleukin-2, with assessment of effects of interleukin-2 on both peripheral blood and thoracic-duct lymph.

Recombinant human interleukin-2 (IL-2) was administered by the intravenous (i.v.) or intralymphatic (i.l.) route to 14 patients with advanced malignancy. IL-2 was given in doses of 600,000 IU/kg or 1,050,000 IU/kg daily x 5. Thoracic duct (TD) catheters were placed, and both TD lymphocytes (TDL) and peripheral blood lymphocytes (PBL) were studied. Five of eight patients at the 600,000 IU/kg dose experienced grade III toxicity as did five of six patients at the 1,050,000 IU/kg dose. Two episodes of grade IV toxicity were seen at the higher dose. The i.l. and i.v. routes had a similar toxicity profile excepting lymphangitis/pedal infection, seen only with i.l. administration. One partial response was seen in a patient with renal cell carcinoma. Lymphopenia was seen early in therapy, with lymphocytosis by day 6. Lymphoid yield of the TD catheter fell early in therapy, then increased over baseline by the end of treatment. Intralymphatic administration resulted in a prolonged serum t1/2 and lower serum levels than did i.v. administration, but resulted in higher TD levels. Antibodies against IL-2 were ubiquitous but had no clear effects. Lymphocyte trafficking studies suggested that IL-2 affected lymphocyte redistribution to liver, spleen, bone marrow, and lymph nodes. NK activity and phenotype and LAK activity increased in response to IL-2, with no advantage for TDL. Tumor necrosis factor-alpha and gamma-interferon levels increased sporadically with treatment. The i.l. route offered no advantage over the i.v. route, and TDL offered no advantage over PBL.