Decreased T cell response to mitogen and increased anti-cytoplasmic antibody in drug-free schizophrenic patients

ABSTRACT

Apart from genetic and environmental factors, activation of autoreactive mechanisms has been proposed to play a role in the pathogenesis of schizophrenia. In recent years, considerable work has been carried out to understand the role and contribution of the immune system in this disease. To investigate the T cell response to phytohaemagglutinin [PHA] and determine the serum levels of anti-nuclear antibody [ANA], anti-cytoplasmic antibody [ACA], and circulating immune complexes [CIC] in schizophrenic patients. A total of 30 drug-free schizophrenic patients and 42 healthy controls were enrolled in this study. T cell proliferation in response to PHA was measured using Methyl Thiazol Tetrazolium test. ANA and ACA were measured by indirect immunofluorescence. CIC concentration was determined using poly ethylene glycol precipitation assay. Mean PHA response was 1.96 +/- 0.83 in patients and 3.72 +/- 1.39 in healthy controls [p < 0.001]. ANA and CIC concentrations were not significantly different between two groups. In addition, ACA was detected only in patients. Increased production of ACA together with lower T cell response to mitogens in our patients provides evidence for the involvement of autoimmune mechanisms in the pathogenesis of schizophrenia