Polymorphisms of tumor necrosis factor-alpha and interleukin-6 gene and C-reactive protein profiles in patients with idiopathic dilated cardiomyopathy

BACKGROUND AND OBJECTIVES: The tumor necrosis factor-alpha (TNF-α) and interleukin (IL)-6 gene polymorphism has a controversial role in the pathogenesis of cardiovascular disease among different populations. The effect of the cytokine’s gene polymorphism on idiopathic dilated cardiomyopathy (IDCM) is still unresolved. The current study aimed to evaluate the association of the TNF-α −308 G/A and IL-6 −174 G/C polymorphism with IDCM in a Pakistani population. DESIGN AND SETTINGS: Blood samples for this case-control study were collected from the cardiology outpatient department of multiple cardiology centers of Rawalpindi/Islamabad, Pakistan, between July 2012 and December 2012. PATIENTS AND METHODS: IDCM cases (number [n]=250) and healthy controls (n=300) were genotyped using polymerase chain reaction and restriction fragment length polymorphism. RESULTS: The TNF-α −308 variant genotypes GA and AA were more prevalent in patients compared with the control group (P<.0001). Similarly, the IL-6 −174 variant genotypes GC and CC showed a high prevalence in patients with IDCM compared with healthy controls (P=.0019). IDCM cases had a higher prevalence of the TNF-α–308A (P<.0001) and the IL-6 −174C (P=.0008) mutant alleles than did the control group. The IDCM cases bearing the TNF-α−308 and IL-6 variant genotypes revealed elevated levels of high-sensitivity C-reactive protein (hs-CRP) when compared with the corresponding controls (P<.05). CONCLUSION: The TNF-α −308 G/A and IL-6 −174 G/C gene polymorphisms and high levels of hs-CRP may be associated with the pathogenesis of IDCM in the study population.