Action of histamine on PHA chemiluminescence response of blood mononuclear cells in autoimmune patients.

Peripheral blood mononuclear cells (PBMs) of patients suffering from autoimmune diseases showed significantly lower chemiluminescence response to PHA than the controls. High doses of histamine (10(-5) M) inhibited the chemiluminescence while low doses caused a mild enhancement in all groups of patients. The preformed histamine content of the PBMs was not significantly higher in the patients than in the controls. Individually, a reverse correlation was found between the activity of the disease and the sensitivity of the cells to histamine. In very active cases, virtually no inhibition by histamine was found.