Association between IL-6-174G/C polymorphism and the risk of sepsis and mortality: a systematic review and meta-analysis.
BACKGROUND
Recent studies have reported the association between IL-6-174G/C polymorphism and sepsis. However, the results are inconclusive and conflicting. To better understand the role of IL-6-174G/C polymorphism in sepsis, we conducted a comprehensive meta-analysis.


METHODS
Literature search was conducted through PubMed, Embase, Web of Knowledge databases until July 29, 2013. The pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using fixed- or random-effect model based on heterogeneity test in total and subgroup analyses.


RESULTS
Twenty studies on the risk of sepsis and seven studies on sepsis mortality were included. None of the results showed evidence of a significant association between IL-6-174G/C polymorphism and sepsis risk in overall analysis or subgroup analyses based on sepsis type, ethnicity, source of control and age under any genetic model (the allele comparison, the codominant, the recessive or the dominant model). Although there was a statistically significant association between IL-6-174 G/C polymorphism and sepsis-related mortality under the recessive model, the significance did not exist after Bonferroni's correction.


CONCLUSIONS
Current evidence does not support a direct effect of IL-6-174 G/C polymorphism on the risk of sepsis. In addition, there was no association between IL-6-174 G/C polymorphism and sepsis mortality after Bonferroni's correction. Further analyses of gene-environment interactions and more studies based on larger sample size and homogeneous sepsis patients are required.
State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Surgery Research, Daping Hospital, Third Military Medical University, Chongqing, 400042, China.
Jun-wei
JW
Gao
State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Surgery Research, Daping Hospital, Third Military Medical University, Chongqing, 400042, China.
An-qiang
AQ
Zhang
State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Surgery Research, Daping Hospital, Third Military Medical University, Chongqing, 400042, China.
Wei
W
Pan
State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Surgery Research, Daping Hospital, Third Military Medical University, Chongqing, 400042, China.
Cai-li
CL
Yue
State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Surgery Research, Daping Hospital, Third Military Medical University, Chongqing, 400042, China.
Ling
L
Zeng
State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Surgery Research, Daping Hospital, Third Military Medical University, Chongqing, 400042, China.
Wei
W
Gu
State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Surgery Research, Daping Hospital, Third Military Medical University, Chongqing, 400042, China.
Jianxin
J
Jiang
D000328:Adult; D000483:Alleles; D002648:Child; D015870:Gene Expression; D056726:Genetic Association Studies; D006801:Humans; D007223:Infant; D015850:Interleukin-6 / Q000235:genetics*; D008957:Models, Genetic; D016017:Odds Ratio; D020641:Polymorphism, Single Nucleotide; D044469:Racial Groups; D012306:Risk; D018805:Sepsis / Q000208:ethnology / Q000235:genetics* / Q000401:mortality* / Q000473:pathology; D016019:Survival Analysis
C508600:IL6 protein, human; D015850:Interleukin-6