decreased t cell response to mitogen and increased anti-cytoplasmic antibody in drug-free schizophrenic patients

background: 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. objective: 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. methods: 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. results: 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. conclusion: 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.