Histological features of skin reactions to human lymphoid cell line lymphokine in patients with advanced cancer.

Lymphokines (LCL-LK) prepared from the human lymphoid cell line RPMI 1788 were injected intradermally into tumour-bearing patients. Biopsies of skin reactions were obtained for histological study from 30 min. to 72 hr, and for comparison, biopsies were taken at similar times of tuberculin reactions in tuberculin-positive patients. The early response to LCL-LK consisted of polymorph adherence to vascular endothelium (at 30 min.) followed by polymorph exudation, oedema and haemorrhage (1-2 hr); mononuclear and eosinophilic leucocyte emigration began at 4 hr; and by 12 hr, when the reaction was maximal clinically, there was widespread pleomorphic leucocytic infiltration of the dermis. At later times (48-72 hr) skin reactions to LCL-LK showed predominantly mononuclear cell infiltration and hypertrophy of vascular endothelium. Electron microscopy at 48 hr revealed perivascular lymphocytes and macrophages. The skin reaction to LCL-LK appeared to superimpose an early component of marked polymorph infiltration, oedema and haemorrhage upon a mononuclear cell exudation similar to that seen in the tuberculin reaction. It was concluded that the later phase of the skin reaction to lymphoid cell line lymphokine in the human bore a close histological similarity to the established tuberculin reaction. The LCL-LK reaction occurred in patients anergic to recall antigens. Its intensity was mainly related to dose and did not vary substantially between different batches of lymphokines.