Objective To investigate association between tumor necrosis factor alpha (TNF-α) and obsessive compulsive disorder (OCD) in Chinese Han population.Methods Plasma concentrations of TNF-α were measured in 61 drug-free patients who fulfilled DSM-Ⅳ criteria for OCD and 93 healthy controls.TNF-α concentrations in blood were determined by enzyme-linked immunosorbent assay (ELISA).Two polymorphisms of TNF-α gene were investigated in the same patients and healthy controls:-308 G/A and-238 G/A.The allelic and genotypic frequencies of these polymorphisms were examined by using DNA sequencing method.Results Plasma levels of TNF-α did not differ between patients and controls (P=0.292).No significant results were observed for any of the alleles at the-308 G/A or-238 G/A polymorphism of the TNF-α gene.Finally a haplotype consisting of genotypes of these two markers was also examined.No association was observed for any haplotype (P=0.108).Conclusion No significant differences were observed between patients and controls in plasma levels of TNF-α.There is no association between the-308 G/A and-238 G/A TNF-α gene polymorphisms and OCD in our Chinese samples.However,the results need to be replicated in larger samples.
