Cytokine Gene Polymorphisms in Childhood Dilated Cardiomyopathy: Interferon- gamma, Tumor Necrosis Factor-alpha and Transforming Growth Factor - beta 1 Genes Are Associated with the Disease in Turkish Patients

Dilated cardiomyopathy (DCM) is a cardiac muscle disease with reduced left ventricular systolic function[1]. Myocardial inflammation is the most common mechanism in the pathogenesis of cardiomyopathy in which cytokines may play an important role[2]. The objective of this study was to investigate the associations between tumor necrosis factor-alpha (TNF-α, -308), transforming growth factor-beta 1 (TGF-β1, +10, +25), interleukin-10 (IL-10, -1082, -819, and -592), interleukin-6 (IL-6, -174), interferon-gamma (IFN-γ, +874) gene polymorphisms and DCM. Sixteen children with DCM (3 months-13 years) and 21 healthy controls were tested for the cytokine genes with polymerase chain reaction-sequence-specific primers (PCR-SSP). In our results, TNF-α (-308) A allele was higher in DCM (P=0.03). The frequency of TNF-α (-308) GG genotype (low expression) was significantly decreased in DCM (P=0.02). The children with DCM had significantly higher frequencies of IFN-γ (+874) TT genotype (high expression) and allele T while TA genotype (intermediate expression) was lower in patients (P=0.003, P=0.01 and P=0.04, respectively). Haplotype analyses showed that TT/GG and TC/GG ha plotypes of TGF-β1 (high expression) were significantly decreased while TC/GC, CC/GG and TT/GC (intermediate expression) haplotypes were increased (P=0.01 and P=0.04, respectively). There was no association between IL-6 and IL-10 genotypes/haplotypes and DCM (P>0.05).