Association of TNF- ? and IL-1 ? gene Polymorphisms with Preterm Birth- Replication Study and Meta Analysis

Background Imbalance between pro-inflammatory and anti inflammatory cytokine can lead to erratically initiate the labour, leading to PTB. Due to the widespread belief of the role of pro-inflammatory cytokines in preterm birth and limited availability of study data of TNF- and IL1 gene polymorphisms. Replication and Meta analysis was performed to generate promising evidence in order to elucidate their association with preterm birth. Objectives The aim of the current work was to systematically review the available literature for the association of TNF- and IL1 polymorphisms with preterm birth, replicate the association on an Indian population and combine data from the findings using Meta analysis. Methods TNF- (-308G/A) and IL-1 (-511C/T) has been involved in the preterm mechanism, 559 cases and 559 controls were genotyped for these SNPs. Our efforts were to replicate and Meta analyze the currently available data linking TNF- polymorphism and IL-1 to preterm birth. Data sources PubMed and Science Direct (till 2015) Study eligibility criteria The included studies in this review were a) Association of TNF- (-308) G/A and IL-1 (-511) C/T with PTB b) case-control design. The following were excluded a) where no allele frequency was given b) with no full text availability c) IL-1 antagonist. Conclusion Replication analysis reported no association of TNF- (-308) G/A with preterm birth while meta analysis confirmed the positive associations of TNF- (-308) G/A and no association of IL1-511 C/T polymorphisms with preterm birth. In order to arrive at a valid conclusion, more number of studies incorporating large population pools in diverse ethnic groups has to be undertaken