Restoration by levamisole of histamine-inhibited E rosette formation of T lymphocytes of patients with allergies.

Histamine significantly inhibited the E rosette formation of T lymphocytes of patients with allergies in vitro, but had no effect on the E rosette formation of T lymphocytes of healthy subjects. This inhibitory effect was obtained by concentrations of 3.10(-4) down to 3.10(-7) M histamine and depended on the time of incubation. Levamisole an antianergic chemotherapeutic agent, could restore the histamine-inhibited E rosette formation. It is postulated that patients with allergies possess a subpopulation of T lymphocytes bearing histamine receptors and that the inhibitory effect of histamine on E rosette formation is medicated by intracellular cAMP.