Functional polymorphisms of innate immunity receptors are not risk factors for the non-SBP type bacterial infections in cirrhosis

Presence of NOD2 mutations is not associated with hepatic or systemic hemodynamic abnormalities of cirrhosis

BACKGROUND

Patients with cirrhosis who carry NOD2 mutations are susceptible to bacterial infections. The aim was to evaluate the association of NOD2 mutations with hepatic and systemic hemodynamics in cirrhosis.

PATIENTS AND METHODS

This is a secondary analysis of a prospectively collected database in the context of the screening for the INCA trial (EudraCT 2013-001626-26). This cross-sectional study compared hemodynamic findings according to NOD2 status in 215 patients. Patients were genotyped for NOD2 variants (p.N289S, p.R702W, p.G908R, c.3020insC, rs72796367). Hepatic hemodynamic study and right heart catheterization were performed.

RESULTS

Patients had a median age of 59 (IQR 53-66) years, and 144 (67%) were men. Most patients (64%) were Child-Pugh stage B. Sixty-six patients (31%) carried a NOD2 mutation, which was slightly more common among Child-Pugh stage C (p = 0.05), without differences in MELD [wild-type: 13 (10-16); NOD2 variants 13 (10-18)]. No differences in hepatic and systemic hemodynamics were observed according to NOD2 status. If excluding patients on prophylactic or therapeutic antibiotics, again no association between hepatic or systemic hemodynamics and NOD2 status could be observed.

CONCLUSION

NOD2 mutations are not associated with hepatic or systemic hemodynamic abnormalities in patients with decompensated cirrhosis, suggesting that other mechanisms leading to bacterial translocation predominate.

Single Nucleotide Polymorphisms of Toll-like Receptor 4 in Hepatocellular Carcinoma-A Single-Center Study

Hepatocellular carcinoma (HCC) is the most common primary liver tumor leading to significant morbidity and mortality; its exact genetic background is largely unrecognized. Toll-like receptor-4 (TLR4) reacts with lipopolysaccharides, molecules found in the outer membrane of Gram-negative bacteria. In damaged liver, TLR4 expression is upregulated, leading to hepatic inflammation and injury. We tried to investigate the role of the two most common single-nucleotide polymorphisms (SNPs) of TLR4 in HCC-genesis. Aged > 18 years old, cirrhotic patients were included in this study. Exclusion criteria were non-HCC tumors and HIV co-infection. TLR4 SNPs association with HCC occurrence was the primary endpoint, and associations with all-cause and liver-related mortality, as well as time durations between diagnosis of cirrhosis and HCC development or death and diagnosis of HCC and death were secondary endpoints. A total of 52 out of 260 included patients had or developed HCC. TLR4 SNPs showed no correlation with primary or secondary endpoints, except for the shorter duration between HCC development and death in patients with TLR4 mutations. Overall, TLR4 SNPs showed no correlation with carcinogenesis or deaths in patients with liver cirrhosis; patients with TLR4 SNPs that developed HCC had lower survival rates, a finding that should be further evaluated.

Genetic variants of innate immunity receptors are associated with mortality in cirrhotic patients with bacterial infection

BACKGROUND & AIMS

Acute-on-chronic liver failure (ACLF) is characterized by acute decompensation of cirrhosis (AD), organ failure(s) and high risk of short-term mortality with bacterial infection frequently as precipitating event. Innate immune pattern recognition receptors and members of the lectin pathway of complement activation are crucial to the innate immune response to pathogens. The aim of this study was to investigate whether single nucleotide polymorphisms (SNPs) of innate immune components are associated with the occurrence of bacterial infections or mortality in patients with cirrhosis hospitalized for AD or ACLF.

METHODS

Twenty-one innate immunity SNPs with known functional implications were genotyped in 826 AD/ACLF patients included in the CANONIC study. Associations between baseline characteristics of the patients, the occurrence of bacterial infections and survival rate at 90 days of follow-up in relation to the innate immunity genetic variants were analysed.

RESULTS

The NOD2-G908R genetic variant was associated with mortality (HR 2.25, P = .004) independently of age and MELD Score. This association was also found in a predefined subgroup analysis in patients with bacterial infections (HR 2.78, P < .001) along with MBL_Yx (HR 1.72, P = .008) and MASP2_371 (HR 1.67, P = .012) genetic variants. None of the analysed SNPs were significantly associated with the occurrence of acute bacterial infections or spontaneous bacterial peritonitis in particular.

CONCLUSIONS

Innate immune system-specific NOD2-G908R, MBL_Yx and MASP2_371 genetic variants were independently associated with increased risk of short-term mortality in AD/ACLF patients with bacterial infection.

Common NOD2 Risk Variants as Major Susceptibility Factors for Bacterial Infections in Compensated Cirrhosis

Common nucleotide-binding oligomerization domain containing 2 (NOD2) gene variants have been associated with bacterial infections (BIs) in cirrhosis, in particular, spontaneous bacterial peritonitis, and mortality. Our aim was to evaluate the independent association of NOD2 variants with BI according to the decompensation stage.

Diabetes does not increase infection risk or mortality following an infection in patients with cirrhosis and ascites

Both cirrhosis and diabetes are established risk factors for infections. However, it remains uncertain whether diabetes adds to the risk of infections in patients with cirrhosis who are already at high risk of infections, or increases the mortality following an infection. To answer these questions, we followed a cohort of trial participants with cirrhosis and ascites for 1 year to compare the incidence of infections and post-infection mortality between those with or without diabetes.

Methods

We used Cox regression to estimate the hazard ratio (HR) of any infection, adjusting for confounding by patient age, gender, MELD score, albumin, use of proton pump inhibitors and lactulose, cirrhosis aetiology, and severity of ascites. Further, we analysed the mortality after infection.

Results

Among 1,198 patients with cirrhosis and ascites, diabetics (n = 289, 24%) were more likely than non-diabetics (n = 909, 76%) to be old and male, to have low platelets, and to use lactulose. At inclusion, similar proportions of diabetic and non-diabetic patients were taking a quinolone antibiotic (13% vs. 12%) and they had similar median MELD scores (14 vs. 15). During the follow-up, 446 patients had an infection. Diabetes did not increase the HR of infections (adjusted HR 1.08; 95% CI 0.87–1.35). Further, diabetes did not increase the mortality following an infection (adjusted HR 0.93; 95% CI 0.64–1.35).

Conclusions

In patients with cirrhosis and ascites, diabetes did not increase infection risk or mortality after infection. The immune incompetence of each disease did not appear to be additive. In clinical terms, this means that particular attention to infections is not indicated in patients with cirrhosis and diabetes.

Lay summary

Cirrhosis and diabetes are chronic diseases that weaken the immune system and increase the risk of infections, but it is unknown whether their combined effects exceed the effect of cirrhosis alone. We showed that the risk of infections was the same in patients with cirrhosis, ascites and diabetes as in patients with cirrhosis and ascites alone. Thus, their combined effects do not exceed the effect of cirrhosis alone.

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Cirrhosis and diabetes both increase the risk of infections.

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In patients with cirrhosis, diabetes does not increase the risk of infection.

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In patients with cirrhosis, diabetes does not increase mortality among those infected.

Gene Variants, mRNA and NOD1/2 Protein Levels in Tunisian Childhood Asthma

INTRODUCTION

Asthma is a common respiratory childhood disease that results from an interaction between genetic, environmental and immunologic factors. The implication of nucleotide-binding and oligomerization domain 1 and 2 (NOD1/CARD4, NOD2/CARD15) was highlighted in many inflammatory diseases.

METHODS

In this case-control study, we analyzed the association of three NOD2 polymorphisms and one NOD1 variant, in 338 Tunisian asthmatic children and 425 healthy Controls, using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. We also assessed NOD1 and NOD2 mRNA and protein levels by qRT-PCR and ELISA techniques.

RESULTS

The homozygous AA genotype of rs2075820 was a risk factor for asthma (OR 2.39). The influence of the E266K variant in the presence of the heterozygous AG genotype was higher in male than female groups. The homozygous AA genotype was a risk factor associated with asthma, for patients aged between 6 and 18 years OR 2.39, IC95% (1.04-5.49) p < 0.01. The mRNA expression of NOD1, but not NOD2, was enhanced in asthma patients compared to Controls. We noted a significant difference between asthmatics and healthy controls in NOD1 protein expression (asthma patients : 31.18 ± 10.9 pg/ml, Controls: 20.10 ± 2.58 pg/ml; p < 0.001).

CONCLUSIONS

The NOD1 rs2075820 variant was associated with a higher childhood asthma risk and the NOD1 expression at mRNA and protein levels was significantly increased in asthma patients.