Purpose: To evaluate the effect of lamotrigine (LTG) on several humoral and cellular immune functions in children with epilepsy and the change in immunological status in patients with LTG-induced rash. Methods. Sixteen children with epilepsy of unknown origin or secondary to various etiologies undergoing treatment with LTG participated in the humoral and cellular immunological study. Of these, 2 patients development a rash during LTG treatment and are described in detail. Results: No modifications of humoral or cellular immunity (measured at 1 and 3 months) were noted in 14 of the 16 patients during this treatment. In the 2 children who manifested rash, basal immune function was normal. In both, immediately after the skin rash appeared, there was a high increase in the percentage of activated T-helper lymphocytes (CD4-DR) and activated T-suppressor lymphocytes (CD8-DR), a slight increase in percentage B lymphocytes (CD19), and a greater increase in serum concentration of IgE. In 1 of the 2 patients, reevaluation of immunity 20 days after the rash appeared and after LTG suspension showed normal percentages of CD4-DR, CD8-DR, and CD19, whereas the serum concentration of IgE had decreased. Conclusions: The observed immunological results indicate the LTG-induced rash may be considered an immune-mediated hypersensitivity reaction.
