Immune changes in peripheral blood resulting from locally directed interleukin-2 therapy in squamous cell carcinoma of the head and neck.

Interleukin-2 (IL-2) was administered locally by constant intra-arterial infusion in four escalating doses from 3 x 10(4)-3 x 10(7) IU/day to 12 patients with squamous cell carcinoma of the head and neck (SCCHN) in a phase I trial. Lymphocyte phenotypic markers and serum cytokine concentrations were measured over the course of treatment. Serum IL-1-alpha, -beta and IL-6 were not induced at any dose level. Tumour necrosis factor (TNF)-alpha was induced in the 2 patients who showed a clinical response (at the lowest dose) as well as in 4/10 of the non-responders. In addition TNF-beta was induced in 3/10 and IFN-gamma in 5/10 non-responders. Soluble IL-2 receptor concentrations were increased at the two higher doses. The highest dose of IL-2 produced a lymphocytosis after day 5 until the end of administration reflected by a general rise in lymphocyte phenotypic markers. CD25, CD3/HLA-DR and CD56 showed an additional upregulation not accounted for by the lymphocytosis with a suggestion of a bell-shaped dose-response curve for CD25 and CD3/HLA-DR. Administration of IL-2 in this manner has been shown to be well tolerated and has some anti-tumour activity at low doses, with little toxicity.