Decreased T cell levels in patients with warts.

Thymus-derived lymphocyte (T cell) levels were determined in 72 healthy patients who had viral warts, in 21 healthy patients who had been cured of warts from one to 15 years previously, and in 35 age-matched normal controls who had no history of warts. The mean percentage of lymphocytes that formed rosettes with sheep erythrocytes was less in patients with warts and patients previously cured of warts than in normal controls (P less than .001 and P less than .001, respectively). The number of total T cells/cu mm was decreased in untreated patients with warts (P less than .01) but was normal in patients cured of warts for more than one year. In addition, the morphology of the rosettes in the two patient groups differed from the controls; 32% had small numbers of sheep erythrocytes bound loosely to T cells compared with a rosette of numerous erythrocytes closely adherent to the T cell in 91% of the controls. The results suggest a defect of cellular immunity in many healthy patients with warts.