Carbamazepine induced transient monoclonal gammopathy and immunodeficiency.

Immune abnormalities have been found in many patients receiving anti-epileptic drugs. However, the effects of carbamazepine are still conflicting. We report the case of a 31-year-old woman who began carbamazepine treatment because of idiopathic epilepsy of adulthood. After three years of treatment she developed arthralgias and malaise. Complete immunologic evaluation showed a total absence of immunoglobulin M with decreased levels of immunoglobulin A, positive antinuclear antibodies and monoclonal paraproteinemia type IgG-kappa. The possibility of B cell lymphoma or myeloma was ruled out. Skin testing was negative. Bone marrow examination was normal. After carbamazepine discontinuation, levels of IgA and IgM increased until reaching normal values over 3 years. The monoclonal gammopathy of undetermined significance also disappeared over this period. During this period of immunodeficiency, the patient did not complain of any infectious complications.