Serum ribonuclease in patients with lung carcinoma.

Fifty-one previously untreated cases of lung carcinoma and 7 normal healthy controls were evaluated with respect to serum ribonuclease (S-RNase) levels. Cellular immunity was tested in 22 of these 51 cases by leukocyte migration inhibition test (MIT) using extract of culture cell line of lung carcinoma. S-RNase levels in lung carcinomas were significantly elevated. There appeared to be no difference in S-RNase levels by histological classification. More striking was high S-RNase level in disseminated versus localized cases. MIT results indicated impairment of cellular immunity in those cases of more elevated S-RNase. S-RNase may be implicated in blocking phenomenon associated with neoplastic disease.