[Nature of the blocking action of the sera of oncological patients on T-lymphocytes].

Some sera of tumor patients render a blocking effect on the activity of autologous and allogenic T lymphocytes in blasttransformation test to PHA and spontaneous rosette-formation. The activity that block spontaneous rosette-forming reaction is directed against the population of postthymic peripheral lymphocytes but not that of thymocytes. No correlation was found between the serum activity, which block RSP and RBT, and antibodies to PHA, lymphocytotoxins, C-reactive protein and the rheumatoid factor.