Reversal of Acquired Immunodeficiency During Phenytoin and Carbamazepine Therapy

Abstract

We report a patient who at the age of 18 years had bronchiectasis and immune deficiency. He had suffered from recurrent febrile respiratory infections responsive to antibiotics since the age of 8 years. Six years earlier, he had surgery for malignant astrocytoma of the brain, following which he underwent 4 years of irradiation and chemotherapy. When initially seen, he was malnourished and prepubertal and was taking phenytoin. He had a very low IgA, low IgM, and borderline IgG, absent delayed-type hypersensitivity (DTH) skin reactions and response to booster immunizations, reduced lymphocyte transformation to pokeweed mitogen and streptokinase-streptodornase, and reduced neutrophil chemotaxis. During a follow-up of 6 years, after treatment with antibiotics and respiratory therapy, immune function nearly normalized. IgA and IgM normalized, the patient responded to immunizations, and DTH skin reactions to recall antigens became positive. Lymphocyte transformation to mitogens and antigens, as well as neutrophil chemotaxis, normalized in the presence of an increased number of lymphocytes with a suppressor phenotype. Serum IgG became high (1820 mg/dl), with evidence of increased production in vitro. The improvement occurred despite continued administration of phenytoin and the addition of carbamazepine at a later date. Both drugs have been reported to depress IgA and cellular immunity.