Lymphocyte blast transformation responses in measles infection.

Lymphocyte blast transformation responses were studied in eight patients with natural measles infection. A specific response to purified measles virus antigen and a weaker response to crude measles virus antigen were found after infection. The response to purified measles antigen appeared 1-3 weeks after the beginning of the rash, when the great number of proliferating mononuclear cells found in the peripheral blood during the rash was declining. In the first weeks after onset of the rash also leucocyte and lymphocyte numbers were decreased, and specific responses to purified tuberculin (PPD) and to rubella and mumps virus antigens were suppressed. In mitogen stimulation tests there was no significant suppression of phytohaemagglutinin and concanavalin responses in this small series, but the response to pokeweed mitogen was decreased. The responses to antigens other than measles virus antigens recovered in parallel with the increase of the measles-specific response.