Serial in vitro transfer of tuberculin hypersensitivity by sensitised lymphocytes.

An account is given of the experimental serial in vitro transfer of PPD-specific delayed hypersensitivity to peripheral leukocytes using PPD-specific TF solely as the initial source. Transfer was assessed by means of the leukocytes migration inhibition test, the lymphocytes locomotion test and the leukocytes adherence inhibition test. These tests were positive in all the experiments. It is suggested that these results indicates that TF does not act in itself but triggers a reaction that expands the effect of hypersensitivity.