Decreased T Cell Response to Mitogen and Increased Anti-cytoplasmic Antibody in Drug-Free Schizophrenic Patients

Apart from genetic and environmental factors, activation of autoreactive mechanisms has been proposed to play a role in the pathogenesis of schizophrenia. In re-cent 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 indi-rect 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 signifi-cantly different between two groups. In addition, ACA was detected only in patients. Increased production of ACA together with lower T cell response to mito-gens in our patients provides evidence for the involvement of autoimmune mechanisms in the pathogenesis of schizophrenia.