Association between lymphotoxin-α intron +252 polymorphism and sepsis: a meta-analysis

Aetiology of Community-Acquired Pneumonia and the Role of Genetic Host Factors in Hospitalized Patients in Cyprus

Community-acquired pneumonia (CAP) remains the leading cause of hospitalization among infectious disease in Europe, and a major cause of morbidity and mortality. In order to determine and characterize the aetiology of CAP in hospitalized adults in Cyprus, respiratory and blood samples were obtained from hospitalized patients with CAP, and analyzed using Multiplex Real-Time PCR/RT-PCR, and ID/AMR enrichment panel (RPIP) analysis. Probe-based allelic discrimination was used to investigate genetic host factors in patients. The aetiology could be established in 87% of patients. The most prevalent viral pathogens detected were influenza A, SARS-CoV-2, and human rhinovirus. The most common bacterial pathogens detected were Streptococcus pneumoniae, Staphylococcus aureus, and Haemophilus influenzae. Antimicrobial resistance genes were identified in 23 patients. S. aureus was the most common AMR correlated strain in our study. A positive correlation was detected between bacterial infections and the NOS3 rs1799983 G allele and the FCGR2A rs1801274 G allele. A positive correlation was also detected between the TNF-α rs1800629 A allele and sepsis, while a negative correlation was detected with the ACE rs1799752 insertion genotype and the severity of pneumonia. In conclusion, the targeted NGS panel approach applied provides highly sensitive, comprehensive pathogen detection, in combination with antimicrobial resistance AMR insights that can guide treatment choices. In addition, several host factors have been identified that impact the disease progression and outcome.

Association between the Lymphotoxin-α A252g Gene Polymorphism and the Risk of Sepsis and Mortality: A Meta-Analysis

Background

The association between the lymphotoxin-α (LTA) A252G polymorphism and sepsis risk has been extensively studied, but the results have been controversial. This study is aimed at investigating the overall association between the LTA A252G polymorphism and the risk of sepsis/septic shock and sepsis-related mortality.

Methods

We searched the PubMed and EMBASE databases to identify studies that investigated the association between the LTA A252G polymorphism and risks of sepsis, septic shock, and mortality. The relevant data were extracted, and statistical analyses were performed using the Revman 5.0 and STATA 12 software.

Results

A total of 32 publications were included in the meta-analysis. The results demonstrated that the LTA A252G polymorphism showed no significant association with sepsis risk (GG+GA vs. AA: OR = 0.92, 95%CI = 0.79–1.07, p = 0.27) or with sepsis shock risk (GG+GA vs. AA: OR = 1.01, 95%CI = 0.84–1.22, p = 0.91). However, in the subgroup analyzed by ethnicity, the LTA A252G polymorphism significantly decreased sepsis risk in the Asian population for the recessive model [GG vs. GA+AA: OR = 0.82, 95%CI = 0.68–0.99, p = 0.04] but not in the Caucasian population. Moreover, comparisons between sepsis patients who survived and those who did not suggested that the LTA A252G polymorphism decreases the risk of mortality [GG+GA vs. AA: OR = 0.57, 95%CI = 0.41–0.80, p < 0.01].

Conclusion

Our results suggested that the A252G polymorphism in the LTA gene decreased the risk of sepsis in Asians and may reduce mortality in septic individuals.

Variants in LTA, TNF, IL1B and IL10 genes associated with the clinical course of sepsis

The aim of this study was to explore the association between some SNPs of the TNF, LTA, IL1B and IL10 genes with cytokine concentrations and clinical course in Colombian septic patients. We conducted a cross-sectional study to genotype 415 septic patients and 205 patients without sepsis for the SNPs -308(G/A) rs1800629 of TNF; +252 (G/A) rs909253 of LTA; -511(A/G) rs16944 and +3953(C/T) rs1143634 of IL1B; and -1082(A/G) rs1800896, -819(C/T) rs1800871 and -592(C/A) rs1800872 of IL10. The association of theses SNPs with the following parameters was evaluated: (1) the presence of sepsis; (2) severity and clinical outcomes; (3) APACHE II and SOFA scores; and (4) procalcitonin, C-reactive protein, tumor necrosis factor, lymphotoxin alpha, interleukin 1 beta and interleukin 10 plasma concentrations. We found an association between the SNP LTA +252 with the development of sepsis [OR 1.29 (1.00-1.68)]; the SNP IL10 -1082 with sepsis severity [OR 0.53 (0.29-0.97)]; the TNF -308 with mortality [OR 0.33 (0.12-0.95)]; and the IL10 -592 and IL10 -1082 with admission to the intensive care unit (ICU) [OR 3.36 (1.57-7.18)] and [OR 0.18 (0.04-0.86)], respectively. None of the SNPs were associated with cytokine levels, procalcitonin and C-reactive protein serum concentrations, nor with APACHE II and SOFA scores. Our results suggest that these genetic variants play an important role in the development of sepsis and its clinical course.

The Relevance of Coding Gene Polymorphysms of Cytokines and Cellular Receptors in Sepsis

Sepsis is an injurious systemic host response to infection, which can often lead to septic shock and death. Recently, the immune-pathogenesis and genomics of sepsis have become a research topic focusing on the establishment of diagnostic and prognostic biomarkers. As yet, none have been identified as having the necessary specificity to be used independently of other factors in this respect. However the accumulation of current evidence regarding genetic variations, especially the single nucleotide polymorphisms (SNPs) of cytokines and other innate immunity determinants, partially explains the susceptibility and individual differences of patients with regard to the evolution of sepsis. This article outlines the role of genetic variation of some serum proteins which have the potential to be used as biomarker values in evaluating sepsis susceptibility and the progression of the condition.

Association between the -159C/T polymorphism in the promoter region of the CD14 gene and sepsis: a meta-analysis

Background

The association between CD14-159C/T polymorphism and sepsis has been assessed but results of current studies appeared conflicting and inconstant. This analysis was aimed to determine whether the CD14-159C/T polymorphism confers susceptibility to sepsis or is associated with increased risk of death from sepsis.

Method

The authors conducted a comprehensive search of PubMed, EMBASE, ISI Web of Science, Cochrane library, ScienceDirect, Wiley Online Library and CNKI databases according to a prespecified protocol. Language limits were restricted to English and Chinese. Two reviewers independently selected the articles and extracted relevant data onto standardized forms. Disagreements were settled by discussion and suggestions from senior consultants. The strength of association were evaluated by odds ratio (OR) and 95% confidence interval (CI). Studies failed to fit the Hardy-Weinberg-Equilibrium were excluded.

Results

The research identified a total of 2317 full-text articles of which 14 articles met the predefined inclusion criteria. Meta-analysis was performed for allele frequency of C versus T, as well as genotypes CC + CT versus TT (dominant model), CC versus TT + CT (recessive model), CT versus TT and CC versus TT (additive model). All control samples were in Hardy-Weinberg proportion. No significant association between CD14-159C/T polymorphism and sepsis susceptibility or mortality were detected in the overall population. Nonetheless, subgroup analysis of Asian ethnicity revealed significant association between the CD14-159C/T polymorphism and susceptibility to sepsis in additive model (CC versus TT: OR = 0.52, 95% CI 0.29–0.92, p = 0.03) and recessive model (CC versus CT + TT: OR = 0.50, 95% CI 0.30–0.84, p = 0.009). Of note, three out of the five papers included in the subgroup focused exclusively on burn ICU patients.

Conclusions

This meta-analysis demonstrated that CD14-159C/T polymorphism is likely to be associated with susceptibility to sepsis in Asian population, especially for the TT genotype. However, bias may rise for etiologic reasons because the majority of subjects in the subgroup came from burn ICU. CD14-159C/T polymorphism is not relevant to sepsis mortality in any genetic models, regardless of the ethnicities. Due to the exploratory nature of the study, no adjustment for multiple testing was adopted, and therefore the results should be interpreted with precaution. Well-designed studies with larger sample size and more ethnic groups are required to further validate the results.

Electronic supplementary material

The online version of this article (doi:10.1186/s12871-017-0303-9) contains supplementary material, which is available to authorized users.

Neonatal infections in Saudi Arabia: Association with cytokine gene polymorphisms

In recent years, many studies have reported potential associations between cytokine gene polymorphisms and the development, course, and outcome of sepsis, often with apparently conflicting results. The objective of this study was to investigate single nucleotide polymorphism (SNP) in the interleukin (IL)-1β –31 T/C, IL-6 –174 G/C, tumor necrosis factor α (TNF-α) –308 G/A, and interferon γ (IFN-γ) +874 A/T genes for their possible association with susceptibility to early onset sepsis (EOS) in Saudi newborn infants. A total of 205 newborn infants aged 1-2 days were consecutively enrolled onto the study having met the inclusion criteria (as per the research protocol). DNA was extracted from filter papers using the Chelex-100 method. The cytokines SNP were genotyping using Taqman 5’ nuclease allelic discrimination. For cytokine measurements we used the commercially available Enzyme-Linked Immunosorbent Assay (ELISA) kit. Our results show that the circulating IL-1β, IL-6, TNF-α, and IFN-γ were significantly (p < 0.001) elevated in EOS patients compared to suspected and sepsis-free control groups; and IL-1β –31C, IL-6 –174G, TNF-α –308G, and IFN-γ +874A alleles were associated with EOS in Saudi infants. In conclusion, analysis of cytokines concentrations and SNP for the four tested genes can be used as a predictor of sepsis outcome in newborns.

Polymorphisms of the LTA gene may contribute to the risk of myocardial infarction: a meta-analysis

Objective

The lymphotoxin-α (LTA), as one of the mediators of inflammation, may play an important role in the pathogenesis of myocardial infarction (MI). Genetic association studies (GAS) that have investigated the association between three common polymorphisms (A252G, G10A and C804A) of the LTA gene and susceptibility to MI have produced contradictory and inconclusive results. The aim of this meta-analysis is to provide a relatively comprehensive account of the association of these polymorphisms with susceptibility to MI.

Methods

A literature search for eligible GAS published before October 15, 2013 was conducted in the PubMed, Embase, Web of Science, Cochrane Library, and CNKI (China National Knowledge Infrastructure) databases. We performed a meta-analysis of fifteen case-control studies with a total of 22,549 MI patients and 16,105 healthy controls.

Results

For LTA A252G, a borderline significant overall association was found, indicating that GG genotype may confer an increased susceptibility to MI compared to AA and AG genotypes. Based on an ethnicity stratification analysis, a significant association was observed in Asians, but not in Caucasians. For LTA G10A, no significant overall association was found. However, subgroup analysis based on ethnicity suggested that the 10A allele may confer a significant increased susceptibility to MI only in Asian populations. For LTA C804A, the combined results revealed a significantly increased susceptibility to MI for carriers of the 804A allele in both overall analysis and stratified analyses.

Conclusion

This meta-analysis shows that LTA C804A may be associated with an increased susceptibility to MI, whereas LTA A252G and G10A may confer a significant increased susceptibility to MI only in Asians. Thus, these polymorphisms of the LTA gene can probably be used with other genetic markers together to identify individuals at high susceptibility to MI especially in Asians.

Genetic variation in the TNF gene is associated with susceptibility to severe sepsis, but not with mortality

Background

Tumor necrosis factor (TNF) and TNF receptor superfamily (TNFR)-mediated immune response play an essential role in the pathogenesis of severe sepsis. Studies examining associations of TNF and lymphotoxin-α (LTA) single nucleotide polymorphisms (SNPs) with severe sepsis have produced conflicting results. The objective of this study was to investigate whether genetic variation in TNF, LTA, TNFRSF1A and TNFRSF1B was associated with susceptibility to or death from severe sepsis in Chinese Han population.

Methodology/Principal Findings

Ten SNPs in TNF, LTA, TNFRSF1A and TNFRSF1B were genotyped in samples of patients with severe sepsis (n = 432), sepsis (n = 384) and healthy controls (n = 624). Our results showed that rs1800629, a SNP in the promoter region of TNF, was significantly associated with risk for severe sepsis. The minor allele frequency of rs1800629 was significantly higher in severe sepsis patients than that in both healthy controls (P_adj = 0.00046, odds ratio (OR)_adj = 1.92) and sepsis patients (P_adj = 0.002, OR_adj = 1.56). Further, we investigated the correlation between rs1800629 genotypes and TNF-α concentrations in peripheral blood mononuclear cells (PBMCs) of healthy volunteers exposed to lipopolysaccharides (LPS) ex vivo, and the association between rs1800629 and TNF-α serum levels in severe sepsis patients. After exposure to LPS, the TNF-α concentration in culture supernatants of PBMCs was significantly higher in the subjects with AA+AG genotypes than that with GG genotype (P = 0.007). Moreover, in patients with severe sepsis, individuals with AA+AG genotypes had significantly higher TNF-α serum concentrations than those with GG genotype (P_adj = 0.02). However, there were no significant associations between SNPs in the four candidate genes and 30 day mortality for patients with severe sepsis.

Conclusions/Significance

Our findings suggested that the functional TNF gene SNP rs1800629 was strongly associated with susceptibility to severe sepsis, but not with lethality in Chinese Han population.

Tumor necrosis factor (TNF) and lymphotoxin-alpha (LTA) single nucleotide polymorphisms: importance in ARDS in septic pediatric critically ill patients

Accumulating evidence indicates that genetic background influences the outcome of sepsis, which despite medical advances continues to be a major cause of morbidity and mortality. This study aimed to evaluate the influence of SNPs LTA +252A>G, TNF-863C>A and TNF-308G>A on susceptibility to sepsis, acute respiratory distress syndrome (ARDS), septic shock and sepsis mortality. A prospective case-control study was carried out in a Brazilian pediatric intensive care unit and included 490 septic pediatric patients submitted to mechanical ventilation and 610 healthy children. No SNP association was found with respect to sepsis susceptibility. Nevertheless, a haplotype was identified that was protective against sepsis (+252A/-863A/-308G; OR=0.65; p=0.03). We further observed protection against ARDS in TNF-308 GA genotype carriers (OR=0.29; p=0.0006) and -308A allele carriers (OR=0.40; p=0.003). In addition, increased risk for ARDS was detectable with the TNF-863 CA genotype (OR=1.83; p=0.01) and the -863A carrier status (OR=1.82; p=0.01). After stratification according to age, this outcome remained significantly associated with the -308GA genotype in infants. Finally, protection against sepsis-associated mortality was found for the TNF-308 GA genotype (OR=0.22; p=0.04). Overall, our findings document a protective effect of the TNF-308 GA genotype for the ARDS and sepsis mortality outcomes, further providing evidence for an increased risk of ARDS associated with the TNF-863 CA genotype. Trial registration (www.clinicaltrials.gov): NCT00792883.