HLA antigens and the reactivity of lymphocytes to some drugs and PHA

Peripheral blood lymphocytes from 15 healthy subjects, selected on the basis of their HLA types, were cultured in vitro in the presence of PHA and of a number of drugs which bind adrenergic or dopaminergic receptors (dopamine, norepinephrine, chlorpromazine, haloperidol, propranolol and apomorphine). The results obtained are consistent with an interference between HLA-A1 and cross-reacting specificities and the effect explained by these drugs on the lymphocyte activation by PHA. The possibility is suggested that HLA-A1 and cross-reacting antigens interfere with the binding of such drugs to the cell membrane receptors.