Genetic Polymorphisms in Sepsis

Association between vitamin D receptor gene variants and neonatal sepsis: A systematic review and meta-analysis

The objective of this systematic review and meta-analysis was elucidating the association of VDR SNPs (FokI, TaqI, BsmI, BgII, and ApaI) with neonatal sepsis. Literature search was performed to retrieve records published until August 2nd, 2023 (PROSPERO registration: CRD42023451355). Meta-analysis was carried out to determine the pooled estimates for Odds Ratio (OR). A total of four studies were included with 500 neonates (250 sepsis cases and 250 healthy controls). There was an association observed between TaqI SNP with neonatal sepsis for CT vs. CC+TT (OR=1.95) and TT vs CT+CC (OR=0.40). Moreover, the pooled estimates also suggested that CC vs. CT+TT (OR= 0.37) and C vs. T (OR=0.66) of FokI SNP were significantly associated with neonatal sepsis. SNP of BgII was found to be significantly associated with neonatal sepsis, but only reported in a single study.

Laboratory diagnosed microbial infection in English UK Biobank participants in comparison to the general population

Understanding the genetic and environmental risk factors for serious bacterial infections in ageing populations remains incomplete. Utilising the UK Biobank (UKB), a prospective cohort study of 500,000 adults aged 40-69 years at recruitment (2006-2010), can help address this. Partial implementation of such a system helped groups around the world make rapid progress understanding risk factors for SARS-CoV-2 infection and COVID-19, with insights appearing as early as May 2020. In principle, such approaches could also to be used for bacterial isolations. Here we report feasibility testing of linking an England-wide dataset of microbial reporting to UKB participants, to enable characterisation of microbial infections within the UKB Cohort. These records pertain mainly to bacterial isolations; SARS-CoV-2 isolations were not included. Microbiological infections occurring in patients in England, as recorded in the Public Health England second generation surveillance system (SGSS), were linked to UKB participants using pseudonymised identifiers. By January 2015, ascertainment of laboratory reports from UKB participants by SGSS was estimated at 98%. 4.5% of English UKB participants had a positive microbiological isolate in 2015. Half of UKB isolates came from 12 laboratories, and 70% from 21 laboratories. Incidence rate ratios for microbial isolation, which is indicative of serious infection, from the UKB cohort relative to the comparably aged general population ranged from 0.6 to 1, compatible with the previously described healthy participant bias in UKB. Data on microbial isolations can be linked to UKB participants from January 2015 onwards. This linked data would offer new opportunities for research into the role of bacterial agents on health and disease in middle to-old age.

Endothelial Damage in Sepsis: The Importance of Systems Biology

The early diagnosis and appropriate stratification of sepsis continues to be one of the most important challenges in modern medicine. Single isolated biomarkers have not been enough to improve diagnostic and prognostic strategies and to progress toward therapeutic goals. The information generated by the human genome project has allowed a more holistic approach to the problem. The integration of genomics, transcriptomics, proteomics and metabolomics in sepsis has allowed us to progress in the knowledge of new pathways which are pathophysiologically involved in this disease. Thus, we have understood the importance of and complex interaction between the inflammatory response and the endothelium. Understanding the role of important parts of the microcirculation, such as the endothelial glycocalyx and its interaction with the inflammatory response, has provided early recognition elements for clinical practice that allow the rational use of traditional medical interventions in sepsis. This comprehensive approach, which differs from the classical mechanistic approach, uses systems biology to increase the diagnostic and prognostic spectrum of endothelial damage biomarkers in sepsis, and to provide information on new pathways involved in the pathophysiology of the disease. This, in turn, provides tools for perfecting traditional medical interventions, using them at the appropriate times according to the disease's pathophysiological context, while at the same time discovering new and improved therapeutic alternatives. We have the challenge of transferring this ideal scenario to our daily clinical practice to improve our patients' care. The purpose of this article is to provide a general description of the importance of systems biology in integrating the complex interaction between the endothelium and the inflammatory response in sepsis.

A functional polymorphism at the miR‑491‑5p binding site in the 3'‑untranslated region of the MMP‑9 gene increases the risk of developing ventilator‑associated pneumonia

Matrix metalloproteinase (MMP)‑9 is associated with the severity of ventilator‑associated pneumonia (VAP), while an rs1056629 SNP located in the 3'‑untranslated region (UTR) of MMP‑9 affects the microRNA (miRNA/miR)‑491‑mediated regulation of MMP‑9 expression. In the present study, the effect of rs1056629 on the development of VAP in patients with chronic obstructive pulmonary disease (COPD) was investigated. Patients with COPD were enrolled in the study and their genotypes of rs1056629 (CC, CA or AA) were determined. ELISA was used to analyze the levels of TNF‑α and IL‑6 in the monocytes of patients with COPD carrying differential genotypes of rs1056629. Reverse transcription‑quantitative PCR was carried out to evaluate the expression of miR‑491 and MMP‑9 mRNA in the different groups of patients with COPD. Luciferase assay was used to confirm the inhibitory role of miR‑491 in MMP‑9 expression. Western blot analysis was carried out to assess the expression of MMP‑9 protein in A549 and H1299 cells transfected with miR‑491 mimics. The risk and severity of VAP were significantly elevated in patients with COPD carrying the CC and AC genotypes of rs1056629. Although there was no difference in the expression of miR‑491 in patients carrying different genotypes of rs1056629, the expression levels of TNF‑α, IL‑6 and MMP‑9 were increased in patients with COPD carrying the CC and AC genotypes of rs1056629. The results of luciferase assay revealed that miR‑491 inhibited the expression of MMP‑9 through direct binding to the 3'UTR of MMP‑9. Transfection of miR‑491 mimics into A549 and H1299 cells markedly suppressed the expression of MMP‑9 in a concentration‑dependent manner. On the whole, the findings of the present study confirm that the CC and AC genotypes of rs1056629 increase the risk of developing VAP in patients with COPD by increasing the expression of MMP‑9.

Persistence of Lipoproteins and Cholesterol Alterations after Sepsis: Implication for Atherosclerosis Progression

(1) Background: Sepsis is one of the most common critical care illnesses with increasing survivorship. The quality of life in sepsis survivors is adversely affected by several co-morbidities, including increased incidence of dementia, stroke, cardiac disease and at least temporary deterioration in cognitive dysfunction. One of the potential explanations for their progression is the persistence of lipid profile abnormalities induced during acute sepsis into recovery, resulting in acceleration of atherosclerosis. (2) Methods: This is a targeted review of the abnormalities in the long-term lipid profile abnormalities after sepsis; (3) Results: There is a well-established body of evidence demonstrating acute alteration in lipid profile (HDL-c ↓↓, LDL-C -c ↓↓). In contrast, a limited number of studies demonstrated depression of HDL-c levels with a concomitant increase in LDL-C -c in the wake of sepsis. VLDL-C -c and Lp(a) remained unaltered in few studies as well. Apolipoprotein A1 was altered in survivors suggesting abnormalities in lipoprotein metabolism concomitant to overall lipoprotein abnormalities. However, most of the studies were limited to a four-month follow-up and patient groups were relatively small. Only one study looked at the atherosclerosis progression in sepsis survivors using clinical correlates, demonstrating an acceleration of plaque formation in the aorta, and a large metanalysis suggested an increase in the risk of stroke or acute coronary event between 3% to 9% in sepsis survivors. (4) Conclusions: The limited evidence suggests an emergence and persistence of the proatherogenic lipid profile in sepsis survivors that potentially contributes, along with other factors, to the clinical sequel of atherosclerosis.

Clinical relevance of single nucleotide polymorphisms in the CXCL1 and CXCL12 genes in patients with major trauma

BACKGROUND

Genetic backgrounds have been recognized as significant determinants of susceptibility to sepsis. CXC chemokines play a significant role in innate immunity against infectious diseases. Genetic polymorphisms of CXC chemokine genes have been widely studied in inflammatory and infectious diseases but not in sepsis. Thus, we aimed to investigate the clinical relevance of CXC chemokine gene polymorphisms and susceptibility to sepsis in a traumatically injured population.

METHODS

Thirteen tag single nucleotide polymorphisms were selected from CXC chemokine genes using a multimarker tagging algorithm in the Tagger software. Three independent cohorts of injured patients (n = 1700) were prospectively recruited. Selected single nucleotide polymorphisms were genotyped using an improved multiplex ligation detection reaction method. Cytokine production in lipopolysaccharide-stimulated whole blood was measured using an enzyme-linked immunosorbent assay.

RESULTS

Among the 13 tag single nucleotide polymorphisms, four single nucleotide polymorphisms (rs1429638, rs266087, rs2297630, and rs2839693) were significantly associated with the susceptibility to sepsis, and three (rs3117604, rs1429638, and rs4074) were significantly associated with an increased multiple organ dysfunction score in the derivation cohort. However, only the clinical relevance of rs1429638 and rs266087 was confirmed in the validation cohorts. In addition, rs2297630 was significantly associated with interleukin 6 production.

CONCLUSION

The rs1429638 polymorphism in the CXCL1 gene and the rs2297630 polymorphism in the CXCL12 gene were associated with altered susceptibility to sepsis and might be used as important genetic markers to assess the risks of sepsis in trauma patients.

LEVEL OF EVIDENCE

Prognostic and epidemiologic study, level II.

Quality Control Measures and Validation in Gene Association Studies: Lessons for Acute Illness

Acute illness is a complex constellation of responses involving dysregulated inflammatory and immune responses, which are ultimately associated with multiple organ dysfunction. Gene association studies have associated single-nucleotide polymorphisms (SNPs) with clinical and pharmacological outcomes in a variety of disease states, including acute illness. With approximately 4 to 5 million SNPs in the human genome and recent studies suggesting that a large portion of SNP studies are not reproducible, we suggest that the ultimate clinical utility of SNPs in acute illness depends on validation and quality control measures. To investigate this issue, in December 2018 and January 2019 we searched the literature for peer-reviewed studies reporting data on associations between SNPs and clinical outcomes and between SNPs and pharmaceuticals (i.e., pharmacogenomics) published between January 2011 to February 2019. We review key methodologies and results from a variety of clinical and pharmacological gene association studies, including trauma and sepsis studies, as illustrative examples on current SNP association studies. In this review article, we have found three key points which strengthen the potential accuracy of SNP association studies in acute illness and other diseases: providing evidence of following a protocol quality control method such as the one in Nature Protocols or the OncoArray QC Guidelines; enrolling enough patients to have large cohort groups; and validating the SNPs using an independent technique such as a second study using the same SNPs with new patient cohorts. Our survey suggests the need to standardize validation methods and SNP quality control measures in medicine in general, and specifically in the context of complex disease states such as acute illness.

Association between genetic polymorphisms in the autophagy-related 5 gene promoter and the risk of sepsis

Previous studies demonstrated significant roles of autophagy in the pathogenesis of sepsis, but few studies focused on the effect of autophagy-related SNPs on sepsis susceptibility. In this present study, five polymorphisms of ATG5/ATG16L1 were investigated for the possible risk on sepsis in a Chinese Han population. Our results showed that ATG5 expression levels decreased with the severity of sepsis, and rs506027 T > C and rs510432 G > A were associated with sepsis progression and mortality. Moreover, the rs506027 TT and rs510432 GG carriers also exhibited increased expression levels of ATG5. Functional assays showed that ATG5 knockdown elevated the secretion of pro-inflammatory cytokines in THP-1 cells, and the extracted mononuclear cell of the risk C-A carriers exhibited decreased ATG5 expression levels, leading to enhanced releases of TNF-α and IL-1β under LPS stimulation in vitro. Furthermore, ATG5 T-G haplotype mutation showed higher promoter activities compared to C-A haplotype mutation, suggesting the effect of these SNPs on ATG5 gene transcription. Taken together, these results above indicated that these two ATG5 promoter polymorphisms may be functional and clinically significant for sepsis progression, underscoring its potentially therapeutic implications for sepsis and other inflammatory diseases.

Tumor necrosis factor-α -308G/A and -238G/A polymorphisms are associated with increased risks of sepsis: evidence from an updated meta-analysis

Previous studies have reported the relationship between tumor necrosis factor-α (TNF-α) -308G/A and -238G/A polymorphisms and sepsis risk with inconsistent results. The aim of this study was to estimate the association of the two polymorphisms with risk of sepsis or sepsis-related mortality using a meta-analysis. PubMed, Embase, and Web of Science databases were searched up to June 20 2016. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using fixed or random effect model. Twenty-six studies were included in this meta-analysis. Overall, an increased sepsis risk of TNF-α -308G/A was observed (GA vs GG: OR = 1.43, 95% CI: 1.07-1.92; GA/AA vs GG: OR = 1.42, 95% CI: 1.06-1.89). Subgroup analyses showed that the significant association was found in Asians (GA vs GG: OR = 1.63, 95% CI: 1.01-2.63) and adult patients. Similarly, an increased sepsis risk of TNF-α -238G/A was observed in overall and subgroup analyses. However, no significant association was found between TNF-α -308G/A and -238G/A polymorphisms and sepsis-related mortality. These findings indicate that both TNF-α -308G/A and -238G/A polymorphisms were associated with increased risks of sepsis but not sepsis-related mortality. Further studies with larger sample size are needed to confirm these results.

IL-6 gene polymorphisms and sepsis in icu adult romanian patients: a prospective study

Objectives: The goal of the study was to investigate the correlations between the interleukin-6 IL-6 -174 G/C and IL-6 -572 G/C gene polymorphisms and sepsis risk and severity in adult ICU patients.

Materials and Methods: We prospectively assessed 107 septic patients and divided them into two subgroups: organ dysfunction-free sepsis subgroup S (n=60) and septic shock subgroup SS (n=47). A control group of 96 healthy individuals was included. Both patients and controls underwent IL-6 -174 G/C and -572 G/C genotyping and circulating IL-6 in the study group which were measured from samples taken in the first day of sepsis diagnosis.

Results: No differences in the genotype frequencies of the two polymorphisms between study and control groups were identified. The GC genotype and C allele of IL-6 -572 G/C gene polymorphism was statistically significant more frequent in the organ dysfunction-free subgroup (p=0.01, p=0.004 respectively). No statistically significant differences for the IL-6 -174 G/C gene polymorphism were found between the two sepsis subgroups. Circulating IL-6 levels were significantly higher in the septic shock subgroup and among patients with GG genotypes of both studied polymorphisms.

Conclusion: We underline the possible role of IL-6 -572 G/C as a marker of severe evolution. There is no evidence of a direct role of IL-6 -174 G/C gene polymorphism in sepsis risk and outcome. Il-6 levels are correlated with sepsis severity but not with variant genotype of investigated IL-6 gene polymorphisms.

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.

Fc Gamma Receptor IIA (CD32A) R131 Polymorphism as a Marker of Genetic Susceptibility to Sepsis

Sepsis is a devastating disease that can affect humans at any time between neonates and the elderly and is associated with mortality rates that range from 30 to 80%. Despite intensive efforts, its treatment has remained the same over the last few decades. Fc receptors regulate multiple immune responses and have been investigated in diverse complex diseases. FcγRIIA (CD32A) is an immunoreceptor, tyrosine-based activation motif-bearing receptor that binds immunoglobulin G and C-reactive protein, important opsonins in host defense. We conducted a study of 702 patients (184 healthy individuals, 171 non-infected critically ill patients, and 347 sepsis patients) to investigate if genetic polymorphisms in the CD32A coding region affect the risk of septic shock. All individuals were genotyped for a variant at position 131 of the FcγRIIA gene. We found that allele G, associated with the R131 genotype, was significantly more frequent in septic patients than in the other groups (p = 0.05). Our data indicate that FcγRIIA genotyping can be used as a marker of genetic susceptibility to sepsis.

Associations between Single Nucleotide Polymorphisms of High Mobility Group Box 1 Protein and Clinical Outcomes in Korean Sepsis Patients

PURPOSE

High mobility group box 1 (HMGB1) plays a central role in the pathogenesis of sepsis and multiple organ dysfunction syndromes. We investigated the associations of a single nucleotide polymorphism (SNP; rs1045411) in HMGB1 with various clinical parameters, severity, and prognosis in patients with sepsis, severe sepsis, or septic shock.

MATERIALS AND METHODS

We enrolled 212 adult patients followed for 28 days. All patients were genotyped for rs1045411, and the serum levels of HMGB1 and several cytokines were measured.

RESULTS

The proportions of patients according to genotype were GG (71.2%), GA (26.4%), and AA (2.4%). Among patients with chronic lung disease comorbidity, patients with a variant A allele had higher positive blood culture rates and higher levels of various cytokines [interleukin (IL)-1β, IL-6, IL-10, IL-17, and tumor necrosis factor-α] than those with the GG genotype. In the analysis of those with diabetes as a comorbidity, patients with a variant A allele had higher blood culture and Gram-negative culture rates than those with GG genotypes; these patients also had a higher levels of IL-17. In the analysis of those with sepsis caused by a respiratory tract infection, patients with a variant A allele had higher levels of IL-10 and IL-17 (all p<0.05). This polymorphism had no significant impact on patient survival.

CONCLUSION

The variant A allele of rs1045411 appears to be associated with a more severe inflammatory response than the GG genotype under specific conditions.

Genetic polymorphisms and the development of invasive bacterial infections in children

To evaluate the associations between single nucleotide polymorphisms (SNPs) of factors involved in the development of invasive bacterial disease (IBD) in children, 47 SNPs of 18 candidate genes were analysed in 49 children with IBD and 100 controls. The G/T genotype of TLR2 rs2149356 and the C genotype of LTA rs2229094 were associated with significantly reduced risk of developing IBD (P=0.04 and P=0.05, respectively), whereas the C/T genotype of RFP175 rs1585110 was associated with a significantly higher risk of developing IBD (P=0.02). These results support the evidence that some genetic variants of factors involved in innate immunity may influence IBD risk in children.

The influence of genetic polymorphisms in TLR4 and TIRAP, and their expression levels in peripheral blood, on susceptibility to sepsis

The present study aimed to investigate whether genetic polymorphisms in the Toll-like receptor (TLR)-4 and Toll/interleukin-1 receptor (TIR)-associated protein (TIRAP) genes, and/or their expression levels, influence the susceptibility of a patient to sepsis. A total of 106 patients with sepsis were divided into two groups on the basis of their acute physiology and chronic health evaluation (APACHE) II scores: i) Sepsis group A (APACHE II <20) and ii) Sepsis group B (APACHE II >20). In addition, 100 healthy volunteers were enrolled into the control group. Polymerase chain reaction-restriction fragment length polymorphism assay was used to detect the following genetic polymorphisms: The Ser180Leu allele of the TIRAP gene and the Asp299Gly and Thr399I1e alleles of the TLR4 gene. Furthermore, the protein expression levels of TLR4 and TIRAP were analyzed using an enzyme-linked immunosorbent assay. Genetic polymorphisms were not detected for the TLR4 and TIRAP genes; however, the protein expression levels of TLR4 and TIRAP differed significantly between the control, sepsis A and sepsis B groups (P<0.01). An APACHE II score of 20 was used as a baseline in order to differentiate sepsis severity. Pearson analysis demonstrated that TLR4 and TIRAP protein expression levels were positively correlated with sepsis severity (r=0.931 and 0.972; P<0.05), and TLR4 protein expression levels were positively correlated with those of TIRAP (r=0.936; P<0.05). The results of the present study suggested that the protein expression levels of, but not genetic polymorphisms in, TLR4 and TIRAP were associated with the severity of sepsis.

Innate immunity gene expression changes in critically ill patients with sepsis and disease-related malnutrition

The aim of this study was an attempt to determine whether the expression of genes involved in innate antibacterial response (TL R2, NOD 1, TRAF6, HMGB 1 and Hsp70) in peripheral blood leukocytes in critically ill patients, may undergo significant changes depending on the severity of the infection and the degree of malnutrition. The study was performed in a group of 128 patients with infections treated in the intensive care and surgical ward. In 103/80.5% of patients, infections had a severe course (sepsis, severe sepsis, septic shock, mechanical ventilation of the lungs). Clinical monitoring included diagnosis of severe infection (according to the criteria of the ACC P/SCC M), assessment of severity of the patient condition and risk of death (APACHE II and SAPS II), nutritional assessment (NRS 2002 and SGA scales) and the observation of the early results of treatment. Gene expression at the mRNA level was analyzed by real-time PCR. The results of the present study indicate that in critically ill patients treated in the IC U there are significant disturbances in the expression of genes associated with innate antimicrobial immunity, which may have a significant impact on the clinical outcome. The expression of these genes varies depending on the severity of the patient condition, severity of infection and nutritional status. Expression disorders of genes belonging to innate antimicrobial immunity should be diagnosed as early as possible, monitored during the treatment and taken into account during early therapeutic treatment (including early nutrition to support the functions of immune cells).

Clinical associations of host genetic variations in the genes of cytokines in critically ill patients

Host genetic variations may influence a changing profile of biochemical markers and outcome in patients with trauma/injury. The objective of this study was to assess clinical associations of single nucleotide polymorphisms (SNPs) in the genes of cytokines in critically ill patients. A total of 430 patients were genotyped for SNPs in the genes of pro- (IL1B, IL6, IL8) and anti-inflammatory (IL4, IL10, IL13) cytokines. The main end-points were sepsis, mortality and adult respiratory distress syndrome (ARDS). We evaluated the dynamic levels of bilirubin, blood urea nitrogen, creatine kinase, creatinine and lactate dehydrogenase in five points of measurements (between 1 and 14 days after admission) and correlated them with SNPs. High-producing alleles of proinflammatory cytokines protected patients against sepsis (IL1B -511A and IL8 -251A) and mortality (IL1B -511A). High-producing alleles of anti-inflammatory cytokines IL4 -589T and IL13 431A (144Gln) were less frequent in ARDS patients. The carriers of IL6 -174C/C genotypes were prone to the increased levels of biochemical markers and acute kidney and liver insufficiency. Genotype-dependent differences in the levels of biochemical indicators gradually increased to a maximal value on the 14th day after admission. These findings suggest that genetic variability in pro- and anti-inflammatory cytokines may contribute to different clinical phenotypes in patients at high risk of critical illness.

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.

METHODOLOGY

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.

Mannose-binding lectin polymorphisms and the risk of sepsis: evidence from a meta-analysis

Several studies have evaluated the association between mannose-binding lectin (MBL) polymorphisms and sepsis. However, the results are inconclusive and conflicting. To better understand the roles of MBL polymorphisms in sepsis, we conducted a comprehensive meta-analysis. All relevant studies were searched from PubMed, EMBASE and Web of Knowledge databases, with the last report up to 7 May 2013. Twenty-nine studies addressing four MBL polymorphisms (-550G/C, -221G/C, structure variant A/O, Gly54Asp) were analysed for susceptibility to sepsis and one study for sepsis-related mortality. Overall, significant associations between structure variant A/O and susceptibility to sepsis were observed for AO + OO vs. AA [odds ratio (OR) 1·27, 95% confidence interval (CI) 1·05-1·52, P = 0·01] and O vs. A (OR 1·19, 95% CI 1·02-1·40, P = 0·03). In subgroup analysis based on age group, increased risk was found in the paediatric group in the dominant model (OR 1·72, 95% CI 1·16-2·56, P = 0·007). Moreover, there was a slight association between the +54A/B polymorphism and susceptibility to sepsis in Caucasians (recessive model: OR 10·64, 95% CI 1·24-91·65, P = 0·03). However, no association was observed for -550G/C and -221G/C polymorphisms both overall and in subgroup analysis. For sepsis-related mortality, only one study suggested AO/OO was associated with in-hospital mortality in pneumococcal sepsis patients after controlling for confounding variables. Our meta-analysis indicated that MBL structure variants might be associated with susceptibility to sepsis but further studies with a large sample size should be conducted to confirm these findings.

Genetic polymorphisms and sepsis in premature neonates

Identifying single nucleotide polymorphisms (SNPs) in the genes involved in sepsis may help to clarify the pathophysiology of neonatal sepsis. The aim of this study was to evaluate the relationships between sepsis in pre-term neonates and genes potentially involved in the response to invasion by infectious agents. The study involved 101 pre-term neonates born between June 2008 and May 2012 with a diagnosis of microbiologically confirmed sepsis, 98 pre-term neonates with clinical sepsis and 100 randomly selected, otherwise healthy pre-term neonates born during the study period. During the study, 47 SNPs in 18 candidate genes were genotyped on Guthrie cards using an ABI PRISM 7900 HT Fast real-time and MAssARRAY for nucleic acids instruments. Genotypes CT and TT of rs1143643 (the IL1β gene) and genotype GG of rs2664349GG (the MMP-16 gene) were associated with a significantly increased overall risk of developing sepsis (p = 0.03, p = 0.05 and p = 0.03), whereas genotypes AG of rs4358188 (the BPI gene) and CT of rs1799946 (the DEFβ1 gene) were associated with a significantly reduced risk of developing sepsis (p = 0.05 for both). Among the patients with bacteriologically confirmed sepsis, only genotype GG of rs2664349 (the MMP-16 gene) showed a significant association with an increased risk (p = 0.02). Genotypes GG of rs2569190 (the CD14 gene) and AT of rs4073 (the IL8 gene) were associated with a significantly increased risk of developing severe sepsis (p = 0.05 and p = 0.01). Genotype AG of rs1800629 (the LTA gene) and genotypes CC and CT of rs1341023 (the BPI gene) were associated with a significantly increased risk of developing Gram-negative sepsis (p = 0.04, p = 0.04 and p = 0.03). These results show that genetic variability seems to play a role in sepsis in pre-term neonates by influencing susceptibility to and the severity of the disease, as well as the risk of having disease due to specific pathogens.

Immunoinflammatory response in critically ill patients: severe sepsis and/or trauma

Immunoinflammatory response in critically ill patients is very complex. This review explores some of the new elements of immunoinflammatory response in severe sepsis, tumor necrosis factor-alpha in severe acute pancreatitis as a clinical example of immune response in sepsis, immune response in severe trauma with or without secondary sepsis, and genetic aspects of host immuno-inflammatory response to various insults in critically ill patients.

Functional polymorphisms in the gene encoding macrophage migration inhibitory factor are associated with Gram-negative bacteremia in older adults

Macrophage migration inhibitory factor (MIF) is an immune mediator encoded in a functionally polymorphic locus. We found the genotype conferring low expression of MIF to be enriched in a cohort of 180 patients with gram-negative bacteremia, compared with 229 healthy controls (odds ratio [OR], 2.4; P = .04), an association that was more pronounced in older adults (OR, 4.6; P = .01). Among older subjects, those with low expression of MIF demonstrated 20% reduced MIF production from lipopolysaccharide-stimulated peripheral blood monocytes and 30% lower monocyte surface Toll-like receptor 4, compared with those with high expression. Our work suggests that older adults with low expression of MIF may be predisposed to hyporesponsiveness to lipopolysaccharide and gram-negative bacterial infection.

Bench-to-bedside review: future novel diagnostics for sepsis - a systems biology approach

The early, accurate diagnosis and risk stratification of sepsis remains an important challenge in the critically ill. Since traditional biomarker strategies have not yielded a gold standard marker for sepsis, focus is shifting towards novel strategies that improve assessment capabilities. The combination of technological advancements and information generated through the human genome project positions systems biology at the forefront of biomarker discovery. While previously available, developments in the technologies focusing on DNA, gene expression, gene regulatory mechanisms, protein and metabolite discovery have made these tools more feasible to implement and less costly, and they have taken on an enhanced capacity such that they are ripe for utilization as tools to advance our knowledge and clinical research. Medicine is in a genome-level era that can leverage the assessment of thousands of molecular signals beyond simply measuring selected circulating proteins. Genomics is the study of the entire complement of genetic material of an individual. Epigenetics is the regulation of gene activity by reversible modifications of the DNA. Transcriptomics is the quantification of the relative levels of messenger RNA for a large number of genes in specific cells or tissues to measure differences in the expression levels of different genes, and the utilization of patterns of differential gene expression to characterize different biological states of a tissue. Proteomics is the large-scale study of proteins. Metabolomics is the study of the small molecule profiles that are the terminal downstream products of the genome and consists of the total complement of all low-molecular-weight molecules that cellular processes leave behind. Taken together, these individual fields of study may be linked during a systems biology approach. There remains a valuable opportunity to deploy these technologies further in human research. The techniques described in this paper not only have the potential to increase the spectrum of diagnostic and prognostic biomarkers in sepsis, but they may also enable the discovery of new disease pathways. This may in turn lead us to improved therapeutic targets. The objective of this paper is to provide an overview and basic framework for clinicians and clinical researchers to better understand the 'omics technologies' to enhance further use of these valuable tools.

Tumor necrosis factor-α levels early in severe acute pancreatitis: is there predictive value regarding severity and outcome?

GOAL AND BACKGROUND

One of the most important cytokines in pathogenesis of acute pancreatitis is tumor necrosis factor (TNF)-α. The aim of our study was to determine whether the plasma levels of TNF-α in patients with severe acute pancreatitis (SAP) on admission correlate with severity and outcome of SAP.

STUDY

Blood samples were obtained from 100 patients with SAP. Patients were divided into 2 groups according to severity: SAP group (n=69) and SAP-induced multiple organ dysfunction syndrome (MODS) group (n=31). Survivors were patients who were alive 90 days after taking the blood sample for cytokine measurement (53/100). Blood sample for cytokine measurement was drawn immediately after admission. TNF-α was measured by commercial ELISA test in plasma.

RESULTS

When comparing SAP group with SAP-induced MODS group, we found that mean values of TNF-α on admission were 191.5-fold lower in group with SAP-induced MODS (P<0.01). When comparing nonsurvivors with survivors, we found that mean values of TNF-α on admission were 63-fold higher in survivors (P<0.01). At cut-off level of 7.95 pg/mL sensitivity was 83.9% and specificity was 72.5%. Patients with TNF-α level lower than 7.95 pg/mL had 3.2-fold higher probability to develop SAP with MODS. At cut-off level of 10.5 pg/mL sensitivity was 83% and specificity was 77.4%. Patients with TNF-α level higher than 10.5 pg/mL had 4.8-fold higher probability to survive.

CONCLUSIONS

TNF-α is good predictor of severity and outcome. Low TNF-α concentration in patients with SAP predicts development of MODS and fatal outcome.

Dynamic changes in serum soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) and its gene polymorphisms are associated with sepsis prognosis

This study explored the association of sepsis prognosis with dynamic changes in serum soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) and its polymorphisms. We enrolled 80 subjects with sepsis and 80 controls. Serum sTREM-1 was tested on days 1, 3, 5, 7, 10, and 14. PCR sequencing was performed to detect TREM-1 genetic variation on its four exons. sTREM-1 levels were significantly higher in the nonsurvivor than in the survivor group (p < 0.001), and those at each time point were the same (p ≤ 0.001). Of the three tested TREM-1 SNPs (rs144672509, rs2234237, and rs2234246), only rs2234237 (Ser25Thr) was significantly associated with sepsis prognosis in three inheritance models (p < 0.05). However, there was no relationship between TREM-1 polymorphism and dynamic concentration of sTREM-1. Logistic regression showed that sTREM-1, APACHE II, and rs2234237 polymorphism are risk factors for prognosis. Dynamic changes in serum sTREM-1 and rs2234237 polymorphism could be used in sepsis prognosis assessment.

Polymorphisms in the SUFU gene are associated with organ injury protection and sepsis severity in patients with Enterobacteriacea bacteremia

BACKGROUND

Organ injury including acute kidney injury (AKI) and acute lung Injury (ALI) are major contributors to mortality and morbidity in the setting of sepsis. Hedgehog pathway has been recognized as an important mediator in repair of organ injury. There are some clinical predictors associated with the development of organ injury in sepsis; however few host genetic risk factors have been identified and candidate genes for organ injury susceptibility and severity are largely unknown.

METHODS

A prospective cohort study in a tertiary care hospital included 250 adult hospitalized patients with Enterobacteriacea bacteremia. We selected a panel of 69 tagging SNPs for genes in the Hedgehog signaling pathway using the TagSNP functionality of the SNPInfo web server and designed a panel on the GoldenGate Veracode genotyping assay (Illumina). We confirmed Illumina data using Taqman allelic discrimination assays. We assessed SNPs in combination with clinical variables for associations with outcomes and organ injury.

RESULTS

Significant associations were identified using logistic regression models, controlling for age, race and gender. From the 69 tagging SNPs, 5 SNPs were associated with renal function and 2 with APACHEII score after false discovery rate correction. After multivariate analysis SNPs rs10786691 (p=0.03), rs12414407 (p=0.026), rs10748825 (p=0.01), and rs7078511 (p=0.006), all in the suppressor of fused homolog (SUFU) gene, correlated with renal function. Likewise, SUFU SNPs rs7907760 (p=0.009) and rs10748825 (p=0.029) were associated with APACHEII score. SNPs rs12414407 and rs1078825 are in linkage disequilibrium (LD) with rs2296590, a SNP in the 5'-UTR region that is within a predicted transcription factor bind site for CCAAT-enhancer-binding proteins. In multivariate analyses functional SNP rs2296590 was correlated with renal function (p=0.004) and APACHEII score (p=0.049).

CONCLUSIONS

Host susceptibility factors play an important role in sepsis development and sepsis related organ injury. Polymorphisms in the SUFU gene (encoding for a negative regulator of the hedgehog signaling pathway) are associated with protection from Enterobacteriacea bacteremia related organ injury and sepsis severity.

The synergy of -260T T CD14 and -308GG TNF-α genotypes in survival of critically ill patients

Literature suggests that the analysis of several polymorphic genetic markers is more informative than the analysis of a single polymorphism. In this study, we tested whether the shared inheritance of TLR2 and TLR4 and TNF-α allelic variants may act in synergy with -260C>T CD14 SNP on the outcome from critical conditions. We monitored 524 critically ill patients from South Brazilian, daily from the ICU admission to their discharge from hospital, or death. Our results revealed that TLR2, TLR4 or TNF-α SNPs alone did not show a significant role in the outcome from critical illness. However, when we performed a combined analysis with the CD14 inheritance, we detected a significant higher survivor rate in -260TT CD14/-308GG TNF-α individuals (P = 0.037). In the adjusted analysis including the main clinical predictors to mortality, we observed that -260TT/-308GG double-genotype was a significant protective factor towards survival (P = 0.046). An increased probability for survival of -260TT/-308GG was also observed by 'pathway genetic load' analysis (unweighted: P = 0.041; weighted: P = 0.036). When we applied a hazard function analysis with the -260TT/-308GG variable as a discriminating factor, -260TT/-308GG patients group had, in fact, a higher survivor rate (P = 0.024). Connected to the beneficial effect of -260TT CD14, the -308GG TNF-α genotype was protective against the reported over expression of TNF-α caused by -308A rare allele. Results support the hypothesis that the interaction between -260C>T CD14 and -308G>A TNF-α functional SNPs may be synergistically influencing the outcome of critically ill patients.

Ginsenoside Rg1 improves survival in a murine model of polymicrobial sepsis by suppressing the inflammatory response and apoptosis of lymphocytes

BACKGROUND

Unbalanced inflammatory response and lymphocyte apoptosis are the main reasons for high mortality in patients with sepsis. Ginsenoside Rg1 (Rg1), the most important component isolated from Panax ginseng, has long been used to treat inflammatory and immune-related diseases. We designed this study to investigate the therapeutic effect of this agent on cecal ligation and puncture (CLP)-induced sepsis in mice.

MATERIALS AND METHODS

We randomly divided C57BL/6 mice into four experimental groups: sham, sham plus Rg1, CLP, and CLP plus Rg1. We intravenously injected Rg1 (20 mg/kg) 1 h after CLP and evaluated survival, bacterial clearance, cytokine production, histology, neutrophil emigration, and lymphocyte apoptosis.

RESULTS

Our study showed that treatment with Rg1 significantly improved survival in septic mice (P < 0.01). Rg1 administration suppressed the inflammatory response and enhanced bacterial clearance. Histologic examination of lung and liver showed only minor abnormalities in mice that received Rg1. In addition, Rg1 increased neutrophil counts in peritoneal cavity and inhibited lymphocyte apoptosis in thymus and spleen.

CONCLUSIONS

Ginsenoside Rg1 has a protective role against CLP-induced polymicrobial sepsis by attenuating the proinflammatory response, enhancing innate immunity and preserving adaptive immunity. Rg1 could be a promising new agent for treatment of sepsis.

Developing a gene expression model for predicting ventilator-associated pneumonia in trauma patients: a pilot study

Background

Ventilator-associated pneumonia (VAP) carries significant mortality and morbidity. Predicting which patients will become infected could lead to measures to reduce the incidence of VAP.

Methodology/Principal Findings

The goal was to begin constructing a model for VAP prediction in critically-injured trauma patients, and to identify differentially expressed genes in patients who go on to develop VAP compared to similar patients who do not. Gene expression profiles of lipopolysaccharide stimulated blood cells in critically injured trauma patients that went on to develop ventilator-associated pneumonia (n = 10) was compared to those that never developed the infection (n = 10). Eight hundred and ten genes were differentially expressed between the two groups (ANOVA, P<0.05) and further analyzed by hierarchical clustering and principal component analysis. Functional analysis using Gene Ontology and KEGG classifications revealed enrichment in multiple categories including regulation of protein translation, regulation of protease activity, and response to bacterial infection. A logistic regression model was developed that accurately predicted critically-injured trauma patients that went on to develop VAP (VAP+) and those that did not (VAP−). Five genes (PIK3R3, ATP2A1, PI3, ADAM8, and HCN4) were common to all top 20 significant genes that were identified from all independent training sets in the cross validation. Hierarchical clustering using these five genes accurately categorized 95% of patients and PCA visualization demonstrated two discernable groups (VAP+ and VAP−).

Conclusions/Significance

A logistic regression model using cross-validation accurately predicted patients that developed ventilator-associated pneumonia and should now be tested on a larger cohort of trauma patients.

Genetics and genomics in pediatric septic shock

OBJECTIVES

Pediatric septic shock continues to be an important public health problem. Several investigative groups have applied genetic and genomic approaches as a means of identifying novel pathways and therapeutic targets, discovery of sepsis-related biomarkers, and identification of septic shock subclasses. This review will highlight studies in pediatric sepsis with a focus on gene association studies and genome-wide expression profiling.

DATA SOURCES

A summary of published literature involving gene association and expression profiling studies specifically involving pediatric sepsis and septic shock.

SUMMARY

Several polymorphisms of genes broadly involved in inflammation, immunity, and coagulation have been linked with susceptibility to sepsis, or outcome of sepsis in children. Many of these studies involve meningococcemia, and the strongest association involves a functional polymorphism of the plasminogen activator inhibitor-1 promoter region and meningococcal sepsis. Expression profiling studies in pediatric septic shock have identified zinc supplementation and inhibition of matrix metalloproteinase-8 activity as potential, novel therapeutic approaches in sepsis. Studies focused on discovery of sepsis-related biomarkers have identified interleukin-8 as a robust outcome biomarker in pediatric septic shock. Additional studies have demonstrated the feasibility and clinical relevance of gene expression-based subclassification of pediatric septic shock.

CONCLUSIONS

Pediatric sepsis and septic shock are increasingly being studied by genetic and genomic approaches and the accumulating data hold the promise of enhancing our future approach to this ongoing clinical problem.

Genetic polymorphisms within tumor necrosis factor gene promoter region: a role for susceptibility to ventilator-associated pneumonia

Debatable findings exist among various studies regarding the impact of single nucleotide polymorphisms (SNPs) within the promoter region of the tumor necrosis factor (TNF) gene for susceptibility to infections. Their impact was investigated in a cohort of mechanically ventilated patients who developed ventilator-associated pneumonia (VAP). Two-hundred and thirteen mechanically ventilated patients who developed VAP were enrolled. Genomic DNA was extracted and SNPs at the -376, -308 and -238 position of the promoter region of the TNF gene were assessed by restriction fragment length polymorphisms. Monocytes were isolated from 47 patients when they developed sepsis and stimulated by bacterial endotoxin for the production of TNFα and of interleukin-6 (IL-6). Patients were divided into two groups; 166 patients bearing only wild-type alleles of all three studied polymorphisms; and 47 patients carrying at least one A allele of the three studied SNPs. Time between start of mechanical ventilation and advent of VAP was significantly shorter in the second group than in the first group (log-rank: 4.416, p: 0.041). When VAP supervened, disease severity did not differ between groups. Stimulation of TNFα and of IL-6 was much greater by monocytes for patients carrying A alleles. Carriage of at least one A allele of the three studied SNPs at the promoter region of the TNF-gene is associated with shorter time to development of VAP but it is not associated with disease severity. Findings may be related with a role of the studied SNPs in the production of pro-inflammatory cytokines.

Beyond single-marker analyses: mining whole genome scans for insights into treatment responses in severe sepsis

Management of severe sepsis, an acute illness with high morbidity and mortality, suffers from the lack of effective biomarkers and largely empirical predictions of disease progression and therapeutic responses. We conducted a genome-wide association study using a large randomized clinical trial cohort to discover genetic biomarkers of response to therapy and prognosis utilizing novel approaches, including combination markers, to overcome limitations of single-marker analyses. Sepsis prognostic models were dominated by clinical variables with genetic markers less informative. In contrast, evidence for gene-gene interactions were identified for sepsis treatment responses with genetic biomarkers dominating models for predicting therapeutic responses, yielding candidates for replication in other cohorts.

Psoriasis patients are enriched for genetic variants that protect against HIV-1 disease

An important paradigm in evolutionary genetics is that of a delicate balance between genetic variants that favorably boost host control of infection but which may unfavorably increase susceptibility to autoimmune disease. Here, we investigated whether patients with psoriasis, a common immune-mediated disease of the skin, are enriched for genetic variants that limit the ability of HIV-1 virus to replicate after infection. We analyzed the HLA class I and class II alleles of 1,727 Caucasian psoriasis cases and 3,581 controls and found that psoriasis patients are significantly more likely than controls to have gene variants that are protective against HIV-1 disease. This includes several HLA class I alleles associated with HIV-1 control; amino acid residues at HLA-B positions 67, 70, and 97 that mediate HIV-1 peptide binding; and the deletion polymorphism rs67384697 associated with high surface expression of HLA-C. We also found that the compound genotype KIR3DS1 plus HLA-B Bw4-80I, which respectively encode a natural killer cell activating receptor and its putative ligand, significantly increased psoriasis susceptibility. This compound genotype has also been associated with delay of progression to AIDS. Together, our results suggest that genetic variants that contribute to anti-viral immunity may predispose to the development of psoriasis.

Endothelial nitric oxide synthase 894G→T but not -786T→C gene polymorphism is associated with organ dysfunction and increased mortality in patients with severe sepsis

BACKGROUND

Endothelial nitric oxide synthase (eNOS) -786T→C and 894G→T polymorphisms have been associated with eNOS dysfunction, which might further compromise microcirculatory blood flow during sepsis and increase the risk of organ injury. The purpose of this study is to investigate the association of those two eNOS gene polymorphisms with the severity of organ dysfunction and outcome in patients with severe sepsis.

METHODS

A cohort of patients with severe sepsis was studied and genotyped for eNOS -786T→C and 894G→T polymorphisms. Acute Physical and Chronic Health Evaluation score, the Sequential Organ Failure Assessment score, with or without shock, and the outcomes were compared in patients with different genotypes.

RESULTS

One hundred seventeen patients fulfilled with inclusion criteria were enrolled from nine intensive care units of academic hospital in Beijing. In comparison with the GG genotype, patients with the GT genotype (894G→T) had a trend toward an increase in the frequency of shock (87% vs. 68.1%, p=0.071) and significantly fewer days to shock onset (p<0.05). Those patients also had significantly higher Acute Physical and Chronic Health Evaluation II scores (p<0.05), Sequential Organ Failure Assessment scores (p<0.001), and mortality at both 7 days and 28 days (p<0.001). Multivariate analyses identified the GT genotype (894G→T) as an independent risk factor for outcome in patients with severe sepsis. However, we found that the eNOS -786T→C polymorphism was not associated with severity of disease or mortality of patients with sepsis.

CONCLUSIONS

Carriage of the GT genotype at 894 of eNOS gene was associated with the occurrence of shock and impaired organ function.

Angiotensin-converting enzyme polymorphism affects outcome of local Chinese with acute lung injury

INTRODUCTION

Acute Lung Injury (ALI) with genetic predisposition is fatal. Relationship between angiotensin-converting enzyme insertion/deletion (ACE I/D) polymorphism and the prognosis of local Chinese patients with ALI was investigated; meanwhile, the mechanisms involved were explored.

METHODS

101 ALI patients, 408 non-ALI patients and 236 healthy blood donors were enrolled. ACE I/D polymorphism was detected by polymerase chain reaction, then ACE genotype (II, ID, DD) and allele (I, D) frequencies were compared. Clinical data of ALI patients was calculated. Also, peripheral blood mononuclear cells (PBMC) were isolated from healthy volunteers with different ACE genotypes. Lipopolysaccharide (LPS)-induced ACE gene mRNA expression and ACE activity was measured.

RESULTS

There was no significant difference in the frequencies of the genotypes and alleles. Acute Physiology and Chronic Health Evaluation (APACHE) II score was higher in DD subgroup than in II subgroup (19.7 ± 8.7 and 15.6 ± 6.2; P < 0.05). The 28-day mortality was significantly different (17.4%, 26.8%, and 64.3% for II, ID, and DD; P = 0.013). DD genotype was the independent prognostic factor for 28-day outcome. Furthermore, LPS-induced ACE mRNA expression and ACE activity from PBMC in DD genotype subgroup were both significantly higher than those in the other two subgroups.

CONCLUSIONS

ACE I/D polymorphism is a prognostic factor for ALI. Patients with the DD genotype have higher mortality of ALI. Polymorphism influences the expression of ACE gene in LPS-stimulated PBMC, DD genotype leads to higher level of mRNA and enzyme activity. It may be one of the mechanisms involved.