Serum immunoglobulins, complement levels and lymphocyte subpopulations in phenytoin-treated epileptic patients.

The peripheral blood lymphocytes, serum immunoglobulins, C3 and C4 complement protein concentrations of 20 patients with idiopathic epilepsy who were receiving phenytoin were examined and compared with 30 healthy controls in order to obtain a detailed profile of the effects of the drug on the humoral and cellular immune systems. The T-lymphocyte subsets were identified using monoclonal antibodies. A significant decrease in suppressor T-cells (p less than 0.05) and an increase in the ratio of T-helper to T-suppressor lymphocytes (p less than 0.01) have been found. Furthermore, an increase in B-lymphocytes (p less than 0.01) and a significant rise in serum Ig M concentrations (p less than 0.05) have been observed. No significant changes in serum concentrations of Ig G, Ig A and complement proteins were detected.