Prevalence of two tumor necrosis factor gene polymorphisms in premature infants with early onset sepsis

Background: Tumor necrosis factor (TNF) is a central mediator of sepsis. The NcoI polymorphism within the TNF locus has been described as a prognostic marker for mortality in adult patients with sepsis.

Objectives: The aim of our study was to investigate the genotype and allele distribution of 2 TNF gene polymorphisms in preterm infants <32 weeks of gestational age, who developed early-onset sepsis.

Methods: A double-blinded retrospective cohort study was carried out on stored Guthrie blood spot cards with group A including 67 premature infants <32 weeks of gestational age with proven early-onset sepsis and group B including 102 healthy newborn infants (>32 + 0 weeks of gestation). The genotype andallele distribution of the study population were also compared to reference groups of healthy adult volunteers (n = 252 for TNF-beta NcoI and n = 233 for -308 TNF-alpha promoter). Polymorphisms of the TNF-alpha promoter -308 region and the NcoI site of the TNF-beta gene were assessed using PCR followed by melting curve analysis or NcoI digestion. The groups were compared by estimation of Hardy-Weinberg equilibrium.

Results: The overall allele frequency and genotype distribution of the -308 TNF-alpha and NcoI polymorphism of the TNF-beta gene were comparable to the values found in the controls.

Conclusion: The study results suggest that none of the analyzed TNF gene polymorphisms may serve as a prognostic marker for preterm infants at high risk of sepsis.