Methods
The meta-analysis was carried out using the MOOSE guidelines. The studies selected were evaluated on two parameters: a)They must focus on TNF- \(\propto\) 308 A/G polymorphism and b) They must focus on sepsis and sepsis mortality.
The keywords used were: TNF- \(\propto\) 308 A/G, Tumour necrosis factor, sepsis, septic shock, and sepsis mortality. The search was carried out in MEDLINE, Scopus, and Web of Science databases. All articles up to 2019 were considered. A total of 782 articles were retrieved, out of which only 45 full-text articles were found to be eligible. Out of those, 24 were used for meta-analysis after checking the quality of articles. (Figure 1)
Figure 1 shows the selection of studies.
The studies were excluded for one of the following reasons: Duplicate Articles studies considered multiple organ dysfunction and/or sepsis not related to bacterial function. Three reviewers evaluated the titles, abstracts, and text of the articles searched. The final inclusion of articles was considered after the full agreement of the reviewers. It was also statistically analyzed using kappa statistics; the value of 0.87 indicated a high level of agreement between the reviewers, and hence the included studies were finalized. (Table 1)
The included studies compared G/G with G/A, G/A with A/A, and hence the meta-analysis compared the studies taking G/G with G/A or A/A allele combinations. G/A or A/A allele combination is referred to as TNF-2 and G/G as TNF1. The meta-analysis also considered the ethnicity of the study population, and it is believed to have a confounding role in the role of TNF towards sepsis and sepsis mortality.
The meta-analysis was carried out using MedCalc Software. The comparison of TNF factor alpha 1 and 2 among patients was calculated in the two groups. The odds ratio of these studies was used to construct the forest plot. The random-effects model was used with statistical significance at a p-value less than 0.05 to assess TNF factor alpha’s association with sepsis response.