Association Between Serum IL-6, IL-10, IL-12, and IL-23 Levels and Severity of Liver Cirrhosis

The Causal Relationship between Inflammatory Cytokines and Liver Cirrhosis in European Descent: A Bidirectional Two-Sample Mendelian Randomization Study and the First Conclusions

BACKGROUND

Observational studies have highlighted the pivotal role of inflammatory cytokines in cirrhosis progression. However, the existence of a causal link between inflammatory cytokines and cirrhosis remains uncertain. In this study, we conducted a bidirectional Mendelian randomization (MR) analysis at a summarized level to illuminate the potential causal relationship between the two variables.

METHODS

This study utilized genetic variance in cirrhosis and inflammatory cytokines from a genome-wide association study (GWAS) of European descent. The MR-PRESSO outlier test, Cochran's Q test, and MR-Egger regression were applied to assess outliers, heterogeneity, and pleiotropy. The inverse variance weighted method and multiple sensitivity analyses were used to evaluate causalities. Furthermore, the validation set was used for simultaneous data validation.

RESULTS

The inflammatory cytokine monocyte chemoattractant protein 3 (MCP-3) was supposedly associated with a greater risk of cirrhosis. And cirrhosis was significantly correlated with increased levels of hepatocyte growth factor (HGF).

CONCLUSIONS

This study suggests that MCP-3 might be associated with the etiology of cirrhosis, while several inflammatory cytokines could potentially play a role in its downstream development. Additionally, the progression of cirrhosis was associated with elevated levels of HGF, suggesting a possible role for liver repair functions.

Gut Microbiota and Cytokine Profile in Cirrhosis

Background and Aims

Gut dysbiosis and abnormal cytokine profiles are common in cirrhosis. This study aimed to evaluate the correlations between them.

Methods

In the blood plasma of cirrhosis patients and controls, 27 cytokines were examined using a multiplex assay. The plasma levels of nitrites (stable metabolites of the endothelial dysfunction biomarker nitric oxide) and lipopolysaccharide (LPS) were examined. The fecal microbiota was assessed by 16S rRNA gene sequencing.

Results

Levels of IL-1b, IL-2, IL-6, IL-13, IP-10, IFN-g, TNF-a, LPS, and nitrites were higher in cirrhosis patients than in controls, while levels of IL-4, IL-7, and PDGF-BB were lower. The LPS level was directly correlated with the levels of IL-1b, IL1-Ra, IL-9, IL-17, PDGF-BB, IL-6, TNF-a, and nitrites. The nitrite level was significantly directly correlated with the levels of TNF-a, GM-CSF, IL-17, and IL-12, and inversely correlated with the IL-7 level. TNF-a levels were directly correlated with ascites severity and the abundance of Negativicutes, Enterobacteriaceae, Veillonellaceae, and Klebsiella, while inversely correlated with the abundance of Firmicutes, Clostridia, and Subdoligranulum. IFN-g levels were directly correlated with the abundance of Bacteroidaceae, Lactobacillaceae, Bacteroides, and Megasphaera, and inversely correlated with the abundance of Verrucomicrobiota, Akkermansiaceae, Coriobacteriaceae, Akkermansia, Collinsella, and Gemella. IL-1b levels were directly correlated with the abundance of Comamonadaceae and Enterobacteriaceae and inversely correlated with the abundance of Marinifilaceae and Dialister. IL-6 levels were directly correlated with the abundance of Enterobacteriaceae, hepatic encephalopathy, and ascites severity, and inversely correlated with the abundance of Peptostreptococcaceae, Streptococcaceae, and Streptococcus.

Conclusions

The abundance of harmful gut microbiota taxa and endotoxinemia directly correlates with the levels of proinflammatory cytokines.

Correlation Analysis of IL-17, IL-21, IL-23 with Non-Alcoholic Liver Fibrosis and Cirrhosis

Objective

This research aimed to explore the involvement of interleukins (IL) - IL-6, IL-17, IL-21, and IL-23 - in the evolution and diagnosis of non-alcoholic liver fibrosis and cirrhosis.

Methods

The study subjects were selected from the patients who visited the Department of Hepatology of X Hospital in Y City from August 2021 to April 2023. Peripheral blood samples were collected. All participants were divided into liver fibrosis, cirrhosis, hepatitis, and healthy subjects four groups. IL-21, IL-17, IL23, IL-6 were detected by double antibody sandwich.

Results

The results showed that there was a significant difference in the levels of IL-17, IL-21, and IL-23 among the 4 groups (P<0.0001). ROC curve analysis showed that the AUC values of IL-17, IL-21 and liver fiber 4 items were >0.70, suggesting that the diagnostic efficacy of IL-17, IL-21 was similar to that of liver fiber 4 items. Spearman correlation analysis showed that IL-17 had a positive correlation with collagen type III N-peptide, type IV collagen, and Laminin (P < 0.05), and no correlation with Hyaluronic acid (P > 0.05).

Conclusion

IL-17, IL-21, and IL-23 play a pivotal role in the inflammatory pathways associated with liver injuries, establishing themselves as potent auxiliary diagnostic markers in identifying liver fibrosis and cirrhosis.

Baseline Interleukin-6 as a Preoperative Biomarker for Liver Fibrosis

Introduction

Liver (hepatic) fibrosis (LF) is characterized by impaired function and regenerative capacity of the liver and can lead to significantly increased morbidity and mortality in the context of surgical liver resection (LR). For this reason, it is crucial to identify the extent of LF preoperatively. Interleukin-6 (IL-6) is known to play a key role in the pathogenesis of LF, but its exact value as a preoperative marker is unknown. This study aimed to investigate the correlation between preoperatively determined IL-6 and the presence of LF.

Methods

In this prospective study, IL-6 was determined in 134 consecutive patients undergoing LR. Patients with liver cirrhosis (LC) and patients with clinical or laboratory signs of inflammation were excluded. LF was graded by a blinded pathologist with regard to the degree of LF according to the Desmet classification (0-4). Baseline IL-6 and degree of LF were correlated.

Results

A total of 134 patients were prospectively included prior to LR. For 104 patients, LF was graded and inflammatory parameters were available. Thirty-five of these patients showed LC (Desmet 4), and another 33 patients showed preoperatively elevated inflammatory markers. Two of the remaining patients were liver transplant patients. These patients were excluded from the final analysis. According to Desmet, the remaining 34 patients had LF grade 0 or 1 (none or minimal LF) in 26 cases and LF grade 2 or 3 (moderate-to-severe LF) in 8 cases. Correlation of LF with preoperatively determined IL-6 yielded significantly higher IL-6 levels in the group of patients with moderate-to-severe LF (Desmet 2 or 3) compared to the group with none or minimal LF (Desmet 0 or 1; p = 0.0495).

Conclusion

In the context of LR, our results showed a correlation of preoperatively determined IL-6 with the extent of LF present. Higher serum baseline IL-6 concentrations were associated with a higher degree of LF, whereas no other blood parameter or score was that predictive for LF. Our results suggest that baseline IL-6 might serve as a valuable parameter to assess LF prior to LR. More patients need to be analyzed to further evaluate and confirm the predictive accuracy of IL-6 for LF.

Sarcopenia in liver cirrhosis: perspectives from epigenetics and microbiota

Sarcopenia is characterized by the loss of muscle mass and function. It is well known that sarcopenia is often associated with aging, while in recent years, sarcopenia comorbid with chronic diseases such as cirrhosis has attracted widespread attention, whose underlying molecular mechanisms remain unclear. Since cirrhosis and sarcopenia are assumed to be closely interrelated in terms of pathogenesis, this review innovatively discussed the role of epigenetic modifications and microecological dysregulation in sarcopenia in the context of liver cirrhosis. Here we illustrated the relationship between sarcopenia and cirrhosis in the aspect of epigenetics, dysbiosis, and the crosstalk between gene modifications and intestinal microecology. Furthermore, the alterations in cirrhosis patients with sarcopenia, such as inflammatory response and oxidative stress, are found to present synergistic effects in the pathways of epigenetics and dysbiosis leading to sarcopenia. This review proposes that microbiome-based therapies are promising to break the vicious cycle between epigenetic modification and dysbiosis, providing strong support for the use of intestinal microecological interventions to prevent sarcopenia in cirrhotic patients.

Role of Interleukin-6 Family Cytokines in Organ Fibrosis

Background

Organ fibrosis remains an important cause of high incidence rate and mortality worldwide. The prominent role of interleukin-6 (IL-6) family members represented by IL-6 in inflammation has been extensively studied, and drugs targeting IL-6 have been used clinically. Because of the close relationship between inflammation and fibrosis, researches on the role of IL-6 family members in organ fibrosis are also gradually emerging.

Summary

In this review, we systematically reviewed the role of IL-6 family members in fibrosis and their possible mechanisms. We listed the role of IL-6 family members in organ fibrosis and drew two diagrams to illustrate the downstream signal transductions of IL-6 family members. We also summarized the effect of some IL-6 family members' antagonists in a table.

Key Messages

Fibrosis contributes to organ structure damage, organ dysfunction, and eventually organ failure. Although IL-6 family cytokines have similar downstream signal pathways, different members play various roles in an organ-specific manner which might be partly due to their different target cell populations. The pathogenic role of individual member in various diseases needs to be deciphered carefully.

Immune changes over time and survival in patients with cirrhosis treated with non-selective beta-blockers: A prospective longitudinal study

BACKGROUND

Treatment with non-selective beta-blockers (NSBB) has been associated with anti-inflammatory and anti-cancer effects in patients with cirrhosis. This study aims to analyze the impact of chronic NSBB treatment on immune activation and disease progression in stable outpatients with cirrhosis.

METHODS

In this prospective follow-up of 150 patients with cirrhosis, 39 received treatment with NSBB. Blood samples were taken every 6-9 months, and immune and adrenergic variables were measured. Mixed linear models were used to assess the effect of NSBB on these variables over time. Multivariate Cox regression was used to study associations with adverse clinical events (hepatocellular carcinoma, death, or liver transplant).

RESULTS

Median follow-up was 1635 days. NSBB treatment was associated with significantly lower levels of IL-6 (β - 4.7; 95% confidence interval [CI] -6.9, -2.6) throughout the study. During follow-up, 11 patients developed hepatocellular carcinoma, 32 died, and 4 underwent liver transplant. Patients with higher concentrations of IL-10, IL-6 and IFN-γ developed more clinical events. Event-free survival was significantly better in patients treated with NSBB (hazard ratio 0.36, 95% CI 0.18, 0.71) in a multivariate Cox regression adjusted for Child-Pugh-Score, esophageal varices, and platelets.

CONCLUSION

Chronic treatment with NSBB in patients with stable cirrhosis gives rise to a different state of immune activation, characterized by lower concentrations of IL-6 over time, and it is associated with a reduced risk of adverse event (death, hepatocellular carcinoma, or transplant), after controlling for disease severity.

Vascular Extracellular Vesicles Indicate Severe Hepatopulmonary Syndrome in Cirrhosis

Background: Hepatopulmonary syndrome (HPS) is a pulmonary vasculature complication in the setting of liver disease that is characterized by pathological vasodilation resulting in arterial oxygenation defects. We investigated the role of extracellular vesicles (EV) in cirrhosis patients with HPS, as well as the functional effect of EV administration in a common bile duct ligation (CBDL) HPS mouse model. Methods: A total of 113 cirrhosis patients were studied: 42 (Gr. A) with HPS and 71 (Gr. B) without HPS, as well as 22 healthy controls. Plasma levels of EV associated with endothelial cells, epithelial cells, and hepatocytes were measured. The cytokine cargoes were estimated using ELISA. The effect of EV administered intranasally in the CBDL mouse model was investigated for its functional effect in vascular remodeling and inflammation. Results: We found endothelial cells (EC) associated EV (EC-EV) were elevated in cirrhosis patients with and without HPS (p < 0.001) than controls. EC-EV levels were higher in HPS patients (p = 0.004) than in those without HPS. The epithelial cell EVs were significantly high in cirrhosis patients than controls (p < 0.001) but no changes found in patients with HPS than without. There was a progressive increase in EC-EV levels from mild to severe intrapulmonary shunting in HPS patients (p = 0.02 mild vs. severe), and we were able to predict severe HPS with an AUROC of 0.85; p < 0.001. An inverse correlation of EC-EVs was found with hemoglobin (r = −0.24; p = 0.031) and PaO2 (r = 0.690; p = 0.01) and a direct correlation with MELD (r = 0.32; p = 0.014). Further, both TNF-α (p = 0.001) and IL-1β (p = 0.021) as cargo levels were significantly elevated inside the EVs of HPS patients than without HPS. Interestingly, upon administration of intranasal EVs, there was a significant decrease in Evans blue accumulation and lung wet–dry ratio (p = 0.042; 0.038). A significant reduction was also noticed in inflammation and cholestasis. Conclusion: High levels of plasma EC-EV levels were found in patients with HPS with elevated pro-inflammatory cytokine cargoes. EC-EVs were indicative of severe HPS condition. In the CBDL HPS model, we were able to prove the beneficial effects of improving vascular tone, inflammation, and liver pathogenesis.