Effects of Short-term Administration of Antipsychotic Drugs on Lymphocyte Subsets in Schizophrenic Patients

To the Editor.—  Studies of various immunological parameters in schizophrenic patients are potentially confounded by the possible effects of neuroleptic medication on the immune system. Certain neuroleptic drugs, including the phenothiazines, chlorpromazine, and thioridizine, have been associated with the development of antinuclear-and and anti—single-stranded DNA antibodies, elevated serum rheumatoid factor, and even splenomegaly.¹ Clozapine, a dibenzodiazepine derivative, has been reported to produce a potentially lethal agranulocytosis in a small percentage of patients,^2,3 and therefore may have direct effects on hematopoiesis.In this issue of the Archives, we demonstrate that a subgroup of schizophrenic patients (approximately 30%) have elevated numbers of CD5⁺ (Leu1) B lymphocytes.⁴ This subset of B lymphocytes has been shown by several laboratories to be elevated in patients with certain autoimmune disorders.^5-7 The CD5⁺ B lymphocytes are known to spontaneously proliferate in vitro⁸ and preferentially produce autoantibodies.^5,9,10 In our study,⁴ schizophrenic