Biological variations, genetic polymorphisms and familial resemblance of TNF-α and IL-6 concentrations: STANISLAS cohort

Cytokines are involved in the development of several inflammatory diseases and atherosclerosis. Their variations in healthy individuals are not well defined. The aims of this study were: firstly, to identify factors affecting biological variation of interleukin-6 (IL-6) and tumour necrosis factor-alpha (TNF- α ); secondly, to study their family resemblance; and thirdly, to evaluate the effect of two TNF- α (−308G/A and −238G/A) and two IL-6 polymorphisms (174G/C and −572G/C) on their corresponding circulating levels. A total of 171 healthy families selected from the STANISLAS cohort were studied. Age was negatively related to TNF- α concentrations in offspring only (both sons and daughters). Additionally, IL-6 and TNF- α levels were differently influenced by gender, white blood cells, tobacco consumption, and HDL-cholesterol level. A weak significant familial resemblance for TNF- α concentration was observed in siblings only. There was no significant familial resemblance for IL-6 levels. The TNF- α −308A allele was associated with decreased TNF- α concentrations in both offspring aged less than 18 and males without overweight (BMI