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 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

Increased natural killer cell activity in schizophrenic patients

Schizophrenia has been associated with altered immunity. Different studies regarding natural killer cell activity [NKA] in schizophrenic patients have shown inconsistent results. To evaluate NK cell activity in schizophrenic patients in comparison with healthy control individuals. 30 medication-free schizophrenic patients and 41 healthy sex, age and smoking status matched individuals were included in this study. NK cell activity of case and control subjects was measured by Methyl-Thiazol-Tetrazolium [MTT] test. Statistical analysis of the data was done using SPSS 11.5 software. NK activity of patients and normal subjects had a mean of 36.94 +/- 26.15 [Mean +/- SD] and 22.31 +/- 17.92, respectively. A significant increase in NK activity in schizophrenic patients compared to controls [P = 0.011]. Among patients, NK activity of smokers was significantly lower than that of non-smokers [P = 0.02]. Other demographic factors didn't show any influence on NK activity. The higher activity of NK cells in the schizophrenic patients as compared with the control population could explain the low incidence of cancer in these patients. Decreasing the effect of smoking on NK activity in the patients could be one of the responsible factors for the inconsistency in the results of different studies

Cytokines genes polymorphisms in Iranian patiets with pulmonary tuberculosis

Pulmonary tuberculosis [PTB] has recently become a major problem in developed countries especially in immune compromised HIV infected individuals. Cytokines, their genes and receptors have been implicated in the protective immunity, pathophysiology and development of tuberculosis. In the present study the genotype frequencies of a number of polymorphic genes coding for cytokines or for cytokine receptors have been investigated in a case control study including a group of 40 Iranian PTB patients and 40 healthy individuals. The allelic polymorphism of cytokines SNPs were analyzed according to the protocols of the cytokine component designed for the 13th IHW by the Heidelberg University group. Using PCR-SSP method the following cytokine genes have been determined: IL-1 alpha [T/C -889], IL-1 beta [C/T +3962], IL-1R [C/T pstI 1970], IL-1RA [T/C mspaI 1100], IL-4RA [G/A+1902], IL- 12 [C/A -1188], TGF-beta [C/T codon 10, G/C codon 25], TNF-alpha [G/A -308, G/A -238], IL-2 [T/G -330 G/T +166], IL-4 [T/G -1098, T/C -590, T/C -33], IL-6 [G/C -174, G/A nt 560], IL-10 [G/A -1082, C/T -819, C/A -592]. From IL-1R cluster [pro- inflammatory cytokines] a positive significant association was found at position pstI 1970 C/T polymorphism where the C allele was over presented in the PTB patients [60% vs. 37.5%, P = 0.04].A significant negative association at codon 10 TGF-beta C/T polymorphism has also been shown in our patients, where the T allele was not detected in the patients but 10% of the control subjects expressed this allele [Fisher exact test, P = 0.05]. At this codon allele T [Leucine substitution] is associated with high TGF-beta production. For TNF alpha an insignificant tendency was found at position -308 A/G polymorphism where the G allele carried by 80% of cases and 65% of controls [P = 0.07].At position -238 a negative association was found at the GA polymorphism [10% vs. 25%, P = 0.07]. For IL-6 an insignificant positive association at position -174 C/G polymorphism, G allele [57.5% vs. 37.5, P = 0.07] was found. At the other cytokine genes no specific association were found. In conclusion it is suggested that C allele at position pstI 1970 of IL-1 cluster increases and T allele at codon 10 of TGF-beta decreases in PTB patients

Association of IFN- gamma gene polymorphism with type 1 diabetes in Iranian patients

Type 1 Diabetes [T1D] is a chronic and progressive autoimmune disorder. Cytokines play a critical role in the pathogenesis of T1D. IFN- polymorphism was investigated in T1D and compared with normal controls. Thirty patients suffering fromT1D and 40 normal controls were studied simultaneously using PCR technique. IFN- gene was evaluated at position 5'UTR +5644. There was a significant difference between patient and control groups in TT genotype [P<0.05]. In this study, we found a negative association between IFN- gene at position 5'UTR +5644 and T1D in Iranian patients pointing to T allele as a protective factor against T1D