Delayed cutaneous hypersensitivity reactions in patients with Kaposi's sarcoma.

Defects in cellular immunocompetence have been sought in 25 patients with Kaposi's sarcoma. Skin tests with recall antigens, and PHA lymphocyte stimulation in vitro showed that efferent delayed hypersensitivity responses are intact in the majority. However, attempted sensitization and subsequent challenge with DNCB demonstrated that the afferent limb of the responses was impaired in some patients. This did not appear to be related to the morphology of the tumour or to prognosis.Tumour specific reactions were demonstrated both in vivo and in vitro and these correlated significantly with the morphology and histology. The interpretation of the results for an individual is confounded by the multiplicity of factors influencing the outcome in a particular patient.