Interleukin-6 (-174C) polymorphism and the risk of sepsis in very low birth weight infants: meta-analysis

Background: The guanidine to cytosine transition at position -174 nucleotides relative to the transcription start site in the interleukin (IL)-6 gene has been implicated as a genetic risk factor for the development of sepsis in very low birth weight (VLBW) infants. However, association studies have reported conflicting findings and have generally been underpowered to exclude modest effect sizes. Aim: To systematically assess the evidence for the association of the IL-6 (-174C) polymorphism with the risk of sepsis in VLBW newborn infants. Methods: Systematic review and random effects meta-analysis of genetic association studies. Results: Six cohort studies in which a total of 1323 VLBW infants participated were identified. All were of reasonable methodological quality. Random effects meta-analysis of data from these studies found no evidence of a strong association between carriage of the IL-6 (-174C) polymorphism and sepsis VLBW infants: pooled relative risk 0.90 (95% CI 0.62 to 1.31). Conclusions: The available data are not consistent with more than a modest association between the IL-6 (-174C) polymorphism and neonatal sepsis in VLBW infants. These data do not support screening infants for this allele in order to guide selective antimicrobial prophylaxis.