[Effects of Hodgkin cytotoxic serum on blast transformation of normal and Hodgkin human peripheral blood lymphocytes].

The PHA-resposiveness of normal and Hodgkin patient human peripheral blood lymphocytes has been studied before and after incubation with Hodgkin cytotoxic sera. The following conclusions have been reached: (a) Hodgkin cytotoxic serum is capable of decreasing the PHA-responsiveness of normal lymphocytes and of furtherly impairing the already defective PHA-responsiveness of Hodgkin lymphocytes. (b) The impaired PHA-responsiveness can be restored to the original levels by eluting the cytotoxic antibody. Control experiments in which normal and Hodgkin lymphocytes were put in contact with normal and Hodgkin non-cytotoxic serum showed no decrease of PHA-responsiveness. These data are in agreement with the hypothesis that the presence of serum cytotoxin is at least partly responsible for the immuno-incompetence of T-lymphocytes characteristic of Hodgkin's disease.