Detection of liver injury in IBD using transient elastography

Sodium orthovanadate protects against ulcerative colitis and associated liver damage in mice: insights into modulations of Nrf2/Keap1 and NF-κB pathways

Ulcerative colitis (UC) is a prominent category of disease that is associated with bowel inflammation, it can occur at any period of life and is prevalently rising on a global scale. Dextran sulfate sodium (DSS) has been extensively used to develop colitis due to its ability to mimic human UC, providing consistent and reproducible inflammation, ulceration, and disruption of the epithelial barrier in the colon. Chronic inflammation in the gut can lead to alterations in the gut-liver axis, potentially impacting liver function over time, while direct evidence linking diversion colitis to liver damage is limited. Thus, the present study aims to assess the gut and liver damage against DSS and the possible molecular mechanisms. Forty-seven animals were randomly assigned to six groups. Ulcerative colitis was induced using 2.5% w/v DSS in three alternate cycles, each lasting 7 days, with 1-week remission periods in between. SOV (5 and 10 mg/kg, orally) and the standard drug 5-aminosalicylic acid (100 mg/kg, orally) were administered from the start of the 2nd DSS cycle until the end of the experiment. Biochemical parameters, ELISA, histopathological, and immunohistochemical analyses have been conducted to assess damage in the colon and liver. SOV significantly reduced colitis severity by lowering the DAI score, oxidative stress markers (LPS, IL-1β, MPO, nitrite), and restoring liver biomarkers (SGPT, SGOT). Histopathological findings supported these protective benefits in the liver and gut. Moreover, immunohistochemical analysis showed SOV enhanced the expression of the cytoprotective mediator Nrf2/Keap-1 and reduced the expression of inflammatory mediators NF-κB and IL-6. Present findings concluded that SOV demonstrated a dose-dependent effect against UC through anti-inflammatory and antioxidant pathways, with the highest dose of SOV 10 mg/kg having more significant (p < 0.001) results than the low dose of 5 mg/kg.

Modulation of tryptophan metabolism via AHR-IL22 pathway mediates the alleviation of DSS-induced colitis by chitooligosaccharides with different degrees of polymerization

Oral administration of chitooligosaccharides (COS) has been reported to alleviate colitis in mice. However, the mechanism of action of COS with specific polymerization degree on gut inflammation and metabolism remains unclear. This study aimed to investigate the effects of chitobiose (COS2), chitotetraose (COS4), and chitohexaose (COS6) on colitis, and to elucidate their underlying mechanisms. COS2, COS4, and COS6 were able to significantly alleviate colonic injury and inflammation levels. COS6 has the best anti-inflammatory effect. Furthermore, COS6 could down-regulate the level of indoleamine-2,3-dioxygenase1 (IDO1) and restore the levels of indole, indoleacetic-3-acid (IAA), and indole-3-carbaldehyde (I3A) in the cecum of chronic colitis mice (p < 0.05), thereby regulating tryptophan metabolism. In the aromatic hydrocarbon receptor-IL-22 (AHR-IL-22) pathway, although there were differences between chronic colitis and acute colitis mice, COS intervention could restore the AHR-IL-22 pathway to normal, promote the expression of MUC2, and repair the intestinal mucosal barrier. In conclusion, the results of this study suggested that COS had a good inhibitory effect on IDO1 under inflammation and the changes of AHR and IL-22 levels at different stages of disease development. This provides new insights into the potential use of COS as a functional food for improving intestinal inflammation and metabolism.

Screening for Liver Steatosis and Fibrosis in Patients with Inflammatory Bowel Disease Using Vibration Controlled Transient Elastography with Controlled Attenuation Parameter

BACKGROUND AND AIMS

Inflammatory bowel diseases (IBD) are frequently associated with extraintestinal manifestations, hepatic injury being of concern in these patients. Current literature reports an increased prevalence of liver steatosis and fibrosis in subjects with IBD and the pathophysiology is yet to be completely understood. The aim of this study was to assess the prevalence of non-alcoholic fatty liver disease (NAFLD) in patients with IBD, as well as to determine the factors that connect these two disorders.

METHODS

From September 2021 to June 2022, 82 consecutive IBD patients were enrolled from a tertiary care center hospital in Iasi. Vibration-Controlled Transient Elastography with Controlled Attenuation Parameter (CAP) was used to assess the presence of NAFLD, with a cut-off score for CAP of 248 dB/m. Significant liver fibrosis was considered at a cut-off for liver stiffness measurements (LSM) of 7.2 kPa.

RESULTS

In total, 82 IBD patients (54.8% men, mean age of 49 ± 13 years) were included, 38 (46.3%) of them being diagnosed with NAFLD, with a mean CAP score of 286 ± 35.4 vs. 203 ± 29.7 in patients with IBD only. Age (β = 0.357, p = 0.021), body mass index (BMI) (β = 0.185, p = 0.048), disease duration (β = 0.297, p = 0.041), C-reactive protein (β = 0.321, p = 0.013), fasting plasma glucose (β = 0.269, p = 0.038), and triglycerides (β = 0.273, p = 0.023) were strongly associated with the presence of liver steatosis. The multivariate analysis showed that older age, BMI, and disease duration were strongly associated with significant liver fibrosis in our group.

CONCLUSIONS

NAFLD is a multifaced pathology with growing prevalence among IBD patients. Additional studies are needed to completely understand this problem and to create a solid evidence-based framework for more effective preventative and intervention strategies.

Andrographolide sodium bisulfite ameliorates dextran sulfate sodium-induced colitis and liver injury in mice via inhibiting macrophage proinflammatory polarization from the gut-liver axis

Ulcerative colitis (UC), an inflammatory disease, is widely thought to be associated with colonic barrier damage and inflammatory response. With the destruction of the colonic barrier, lipopolysaccharide (LPS) enters the liver through the portal vein and causes liver injury. Liver injury in turn exacerbates UC to form a vicious cycle, so the treatment of liver injury cannot be ignored. Andrographolide (Andro) has a protective effect against colitis and liver injury, but with low bioavailability. Andrographolide sodium bisulfite (ASB), a water-soluble sulfonate of Andro, has better bioavailability, whether it has a better curative effect against UC and liver injury is rarely reported. Hence, we investigated the protective effect and potential mechanism of ASB against dextran sulfate sodium (DSS)-induced UC and liver injury in mice. The results showed that treatment with ASB significantly relieved the clinical symptoms of UC and liver injury by reducing disease activity index, inhibiting gut-derived LPS leakage, and improving colonic and hepatic injury, and its curative effect was better than Andro. Moreover, ASB effectively decreased the YAP-mediated colonic inflammation and TLR4/MyD88/NF-κB-mediated pro-inflammatory factor release in the liver. Both colonic and hepatic inflammation were associated with macrophage proinflammatory polarization, but they were significantly inhibited by ASB. ASB showed good safety in the treatment of UC and liver injury and has no nephrotoxicity as previously described. In conclusion, ASB has an effective protective effect on DSS-induced UC and liver injury, mainly by suppressing macrophage proinflammatory polarization from the gut-liver axis.

Baicalin Alleviates Short-Term Lincomycin-Induced Intestinal and Liver Injury and Inflammation in Infant Mice

The adverse effects of short-term megadose of antibiotics exposure on the gastrointestinal and liver tissue reactions in young children have been reported. Antibiotic-induced intestinal and liver reactions are usually unpredictable and present a poorly understood pathogenesis. It is, therefore, necessary to develop strategies for reducing the adverse effects of antibiotics. Studies on the harm and rescue measures of antibiotics from the perspective of the gut–liver system are lacking. Here, we demonstrate that lincomycin exposure reduced body weight, disrupted the composition of gut microbiota and intestinal morphology, triggered immune-mediated injury and inflammation, caused liver dysfunction, and affected lipid metabolism. However, baicalin administration attenuated the lincomycin-induced changes. Transcriptome analysis showed that baicalin improved immunity in mice, as evidenced by the decreased levels of intestinal inflammatory cytokines and expression of genes that regulate Th1, Th2, and Th17 cell differentiation, and inhibited mucin type O-glycan biosynthesis pathways. In addition, baicalin improved liver function by upregulating the expression of genes involved in bile acid secretion and lipid degradation, and downregulating genes involved in lipid synthesis in lincomycin-treated mice. Bile acids can regulate intestinal immunity and strengthen hepatoenteric circulation. In addition, baicalin also improved anti-inflammatory bacteria abundance (Blautia and Coprobacillus) and reduced pathogenic bacteria abundance (Proteobacteria, Klebsiella, and Citrobacter) in lincomycin-treated mice. Thus, baicalin can ameliorate antibiotic-induced injury and its associated complications such as liver disease.

Hepatic Steatosis and Fibrosis in Chronic Inflammatory Bowel Disease

Background and Purpose: Chronic inflammatory bowel diseases (IBD) frequently affect extraintestinal organs including the liver. Since limited evidence suggests the presence of liver disease in IBD patients, we studied the frequency of hepatic steatosis and fibrosis in these patients and characterized disease-related factors. Methods: In this retrospective, cross-sectional, hospital-based, single-center study, consecutive patients with Crohn’s disease (CD) and ulcerative colitis (UC) were included who had undergone routine abdominal ultrasound including transhepatic elastography. Hepatic steatosis was diagnosed by hyperechogenicity on B-mode ultrasound and by measuring controlled attenuation parameter (CAP). Hepatic fibrosis was assumed if transhepatic elastography yielded a stiffness > 7 kPa. Results: 132 patients (60% CD) with a median disease duration of 10 years were included. Steatosis assessed by B-mode ultrasound and CAP correlated well. Of the IBD patients, 30.3% had non-alcoholic fatty liver (NAFL). Factors associated with NAFL were age, BMI, duration of disease, as well as serum activities of aspartate-aminotransferase (AST) and gamma-glutamyl-transpeptidase (GGT). In multivariate analysis, only disease duration was independently associated with hepatic steatosis. Hepatic fibrosis was found in 10 (8%) of all IBD patients, predominantly in patients with CD (10/11). Conclusions: Pure hepatic steatosis is common in both CD and UC, whereas hepatic fibrosis occurs predominantly in CD patients. Association of disease duration with NAFLD suggests a contribution of IBD-related pathogenetic factors. Longitudinal studies are needed to better understand the impact of IBD on hepatic disorders.

Multi-Omics Analysis of the Gut-Liver Axis Reveals the Mechanism of Liver Injury in Colitis Mice

Liver injury is a common complication of inflammatory bowel disease (IBD). However, the mechanisms of liver injury development are not clear in IBD patients. Gut microbiota is thought to be engaged in IBD pathogenesis. Here, by an integrated analysis of host transcriptome and colonic microbiome, we have attempted to reveal the mechanism of liver injury in colitis mice. In this study, dextran sulfate sodium (DSS) -induced mice colitis model was constructed. Liver transcriptome showed significant up- and down-regulation of pathways linked to immune response and lipid metabolism, respectively. Whilst the colon transcriptome exhibited dramatic alterations in immune response and pathways associated with cell growth and death. The microbiota of DSS-treated mice underwent strong transitions. Correlation analyses identified genes associated with liver and colon injury, whose expression was associated with the abundance of liver and gut health-related bacteria. Collectively, the results indicate that the liver injury in colitis mice may be related to the intestinal dysbiosis and host-microbiota interactions. These findings may provide new insights for identifying potential targets for the treatment of IBD and its induced liver injury.

Gut-liver-axis: Barrier function of liver sinusoidal endothelial cell

Liver diseases are associated with the leaky gut via the gut-liver-axis. Previous studies have paid much attention to the effect of gut barrier damage. Notably, clinical observations and basic research reveal that the gut barrier damage seldom leads to liver injury independently but aggravates pre-existing liver diseases such as non-alcoholic fatty liver disease and drug-induced liver injury. These evidences suggest that there is a hepatic barrier in the gut-liver-axis, protecting the liver against gut-derived pathogenic factors. However, it has never been investigated which type of liver cell plays the role of hepatic barrier. Under physiological conditions, liver sinusoidal endothelial cell (LSEC) can take up and eliminate virus, bacteriophage, microbial products, and metabolic wastes. LSEC also keeps the homeostasis of liver immune environment via tolerance-inducing and anti-inflammatory functions. In contrast, under pathological conditions, the clearance function of LSEC is impaired, and LSEC turns into a pro-inflammatory pattern. Given its anatomical position and physiological functions, LSEC is proposed as the hepatic barrier in the gut-liver-axis. In this review, we aim to further understand the role of LSEC as the hepatic barrier. Future studies are warranted to seek effective treatments to improve LSEC health, which appears to be a promising approach to prevent gut-derived liver injury.

Gut-Liver Axis: Liver Sinusoidal Endothelial Cells Function as the Hepatic Barrier in Colitis-Induced Liver Injury

Background

Based on the gut–liver axis theory, a leaky gut can aggravate liver injury. However, clinical studies suggest that although gut mucosa damage is commonly observed in inflammatory bowel disease (IBD), it seldom leads to severe liver injury. We hypothesize that there is a hepatic barrier in the gut–liver axis, which protects the liver against gut-derived invasive factors.

Methods

Colitis was induced by dextran sulfate sodium (DSS) in eight different liver injury models in Sprague–Dawley rats. Liver sinusoidal endothelial cell (LSEC) injury was evaluated by a scanning and transmission electron microscope. Neutrophils were depleted by injection of anti-rat polymorphonuclear serum. Two pneumonia models were also induced to investigate the mechanism of neutrophil recruitment and activation. LSECs isolated from rat liver were used to investigate the effect on neutrophil recruitment and activation.

Results

Among eight liver injury models, DSS colitis had no effect on liver injury in three models with normal LSECs. In the other five models with LSEC rupture, liver injury was significantly exacerbated by colitis, and increased hepatic neutrophil accumulation was observed. When neutrophils were depleted, colitis-induced liver injury was significantly attenuated. In pneumonia, liver injury, and colitis models, the level of CXCL1 correlated with the recruitment of neutrophils in different tissues, while DSS colitis and LSEC injury synergistically contributed to increased CXCL1 expression in the liver. In colitis-induced liver injury, neutrophils were activated in the liver. Injured LSECs showed both structural and functional changes, with significantly increased expression of CXCL1 and TNF-α under the stimulation of lipopolysaccharide (LPS). The combination of gut-derived LPS and LSEC-derived TNF-α led to the activation of neutrophils, characterized by enhanced production of reactive oxygen species, pro-inflammatory cytokines, and the formation of neutrophil extracellular traps.

Conclusion

LSECs constitute a vitally important barrier in the gut–liver axis, defending the liver against colitis-induced injury. When LSECs are damaged, they can turn into a pro-inflammatory pattern under the stimulation of LPS. LSEC injury and colitis-derived LPS synergistically contribute to the recruitment and activation of hepatic neutrophils. Neutrophils play a pivotal role as a downstream effector in colitis-induced liver injury.

Insulin Resistance Is Not Increased in Inflammatory Bowel Disease Patients but Is Related to Non-Alcoholic Fatty Liver Disease

BACKGROUND

Insulin resistance (IR) has been linked to inflammatory states. The aim of this study was to determine whether IR is increased in a cohort of inflammatory bowel disease (IBD) patients with low disease activity. We additionally intended to establish which factors were the determinants of IR in this population, including the presence of nonalcoholic fatty liver disease (NAFLD).

METHODS

Cross-sectional study encompassing 151 IBD patients and 174 non-diabetic controls. Insulin and C-peptide serum levels and IR and beta cell function (%B) indices based on homoeostatic model assessment (HOMA2) were assessed in patients and controls. Liver stiffness as measured by transient elastography, and the presence of NAFLD detected via ultrasound were additionally assessed. A multivariable regression analysis was performed to evaluate the differences in IR indexes between patients and controls, and to determine which predictor factors were associated with IR in IBD patients.

RESULTS

Neither HOMA2-IR (beta coef. -0.26 {95%CI -0.64-0.13}, p = 0.19) nor HOMA2-%B (beta coef. 15 {95%CI -14-44}, p = 0.31) indexes differed between patients and controls after fully multivariable analysis. Among classic IR risk factors, obesity, abdominal circumference, and triglycerides significantly and positively correlated with IR indexes in IBD patients. However, most features related to IBD, such as disease patterns, disease activity, and inflammatory markers, were not associated with IR. The presence of NAFLD was independently and significantly associated with beta cell dysfunction in patients with IBD (HOMA2-B grade 4, 251 ± 40 vs. grade 1, 107 ± 37, p = <0.001).

CONCLUSIONS

IR is not increased in IBD patients with low disease activity compared to controls. However, the presence of NAFLD favors the development of IR in patients with IBD.

The Effect of Adiposity on Anti-Tumor Necrosis Factor-Alpha Levels and Loss of Response in Crohn's Disease Patients

INTRODUCTION

A high body mass index is known to adversely affect antitumor necrosis factor-alpha trough levels and secondary loss of response (SLOR) in patients with Crohn's disease. We hypothesize that high levels of adiposity negatively affect these outcomes and aimed to determine if this relationship exists.

METHODS

We performed a retrospective cross-sectional study of 69 patients with Crohn's disease from two tertiary inflammatory bowel disease centers between February 1, 2015, and June 30, 2018. Primary responders to infliximab (IFX) or adalimumab (ADA) who had a trough level performed within 6 months of CT or MRI scan and at least 12 months of clinical follow-up were eligible for inclusion. Body composition as measured on CT/MRI scans were correlated with trough concentration and time SLOR. Multivariate adjustments were made for established risk factors known to affect trough levels and SLOR.

RESULTS

Of 69 included patients, 44 (63.8%) and 25 (36.2%) patients received IFX and ADA, respectively. Multivariate analysis revealed that IFX trough concentrations were inversely correlated with visceral fat area (-0.02 [-0.04, -0.003], P = 0.03), visceral fat index (-0.07 [-0.12, -0.01], P = 0.02) and visceral fat: skeletal muscle area ratio (-3.81 [-7.13, -0.50], P = 0.03), but not body mass index (-0.23 [-0.52, 0.06], P = 0.11). No predictive factors were found for ADA. Increased total adipose area was associated with an increased risk of SLOR in ADA-treated patients, but not IFX-treated patients (hazard ratio = 1.01 [1.002, 1.016], P = 0.011).

DISCUSSION

Visceral adiposity is an important predictor of IFX trough levels, and high total adiposity predicts for SLOR to ADA.

Metabolomic Analysis of the Liver of a Dextran Sodium Sulfate-Induced Acute Colitis Mouse Model: Implications of the Gut-Liver Connection

The incidence of ulcerative colitis (UC) is increasing worldwide, and it has become a growing problem in Asia. Previous research on UC has focused on serum, plasma, urine, gut tissues, and fecal metabolic profiling, but a comprehensive investigation into the correlation between the severity of colitis and changes in liver metabolism is still lacking. Since the liver and gut exchange nutrients and metabolites through a complex network, intestinal diseases can affect both the liver and other organs. In the present study, concentration-dependent dextran sodium sulfate (DSS)-induced ulcerative colitis was employed to examine changes in liver metabolism using a proton nuclear magnetic resonance spectroscopy (¹H-NMR)-and ultra-performance liquid chromatography time of flight mass spectroscopy (UPLC-TOF MS)-based metabolomics study. Using the multivariate statistical analysis method orthogonal projections to latent structures discriminant analysis (OPLS-DA), changes in metabolites depending on the DSS dose could be clearly distinguished. Specifically, hepatic metabolites involved in one-carbon metabolism, carnitine-related metabolism, and nucleotide synthesis were found to be affected by intestinal inflammation, implying the existence of a metabolic connection between the gut and liver. We are currently investigating the significance of this metabolic condition in UC.

High prevalence of non-alcoholic fatty liver disease in patients with inflammatory bowel disease receiving anti-tumor necrosis factor therapy

Background:

Non-alcoholic fatty liver disease (NAFLD) is common in patients with inflammatory bowel disease (IBD). This study evaluated the prevalence of NAFLD and the associated risk factors among IBD patients who received anti-tumor necrosis factor (TNF) therapy.

Methods:

Adult IBD patients receiving anti-TNF therapy (infliximab, adalimumab, certolizumab, golimumab) were enrolled. Hepatic steatosis was assessed by abdominal ultrasound. Patients with a history of excessive alcohol or recent steroid use were excluded. Univariate and multivariate analysis were performed.

Results:

Eighty patients, 55% male, mean age 42±15 years, were enrolled. The sonographic prevalence of NAFLD was 54% (43/80), significantly higher than the general prevalence in the US adult population (30%) (P<0.0001). NAFLD patients had a significantly higher proportion of males, as well as greater body weight and body mass index, compared to non-NAFLD. The Crohns disease activity index (CDAI) was significantly higher among patients with NAFLD. Multivariate analysis demonstrated that a higher CDAI was independently associated with NAFLD, with an odds ratio of 1.6 (95% confidence interval 1.05-2.44; P=0.03).

Conclusions:

The presence of IBD is strongly associated with NAFLD. We identified a high prevalence of NAFLD among IBD patients receiving anti-TNF. CDAI was independently associated with hepatic steatosis. Further studies are still needed to evaluate the pathophysiology of NAFLD development and disease progression among IBD populations.

IRGM Gene Variants Modify the Relationship Between Visceral Adipose Tissue and NAFLD in Patients With Crohn's Disease

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is an increasingly recognized comorbidity in Crohn's disease (CD), but the mechanisms are poorly understood. Autophagy is a highly conserved process regulating innate immunity that contributes to CD susceptibility. Emerging data suggest that variants in the autophagy-governing IRGM gene may contribute to the accumulation of visceral adipose tissue (VAT) and hepatic fat. Our objective was to characterize the relationship between VAT, IRGM gene variants, and NAFLD risk in patients with CD.

METHODS

We included all CD patients in the Prospective Registry in Inflammatory Bowel Disease Study at Massachusetts General Hospital (PRISM) without history of alcohol abuse or liver disease. Hepatic fat was quantified by liver attenuation (LA) on computed tomography, with NAFLD defined by the validated liver:spleen (L:S) ratio. NAFLD severity was estimated by the FIB-4 Index and alanine aminotransferase (ALT). Using logistic regression modeling, we examined the relationship between VAT, autophagy gene variants, and NAFLD risk.

RESULTS

Among 462 patients, 52% had NAFLD. Increasing VAT quartile was associated with reduced LA (mean change, -7.43; 95% confidence interval [CI], -10.05 to -4.81; Ptrend < 0.0001). In the fully adjusted model, patients in the highest VAT quartile had a 2.2-fold increased NAFLD risk (95% CI, 1.21 to 4.14; Ptrend = 0.032) and a 4.2-fold increased risk of ALT>upper limit of normal (ULN) (95% CI, 1.19 to 14.76; Ptrend = 0.017). The relationship between VAT and NAFLD was modified by IRGM variants rs4958847 and rs13361189 (Pinteraction = 0.005 and Pinteraction < 0.001, respectively).

CONCLUSIONS

In a large CD cohort, VAT was directly associated with prevalent NAFLD, and this relationship was augmented by functionally annotated IRGM variants associated with impaired autophagy.

Transient elastography to assess liver stiffness in patients with inflammatory bowel disease

BACKGROUND

Liver injury during inflammatory bowel disease (IBD) is primarily diagnosed by liver biopsy, which has a small but serious risk of severe complications. The aim of this study was to assess liver stiffness, and subsequently the prevalence and associations of liver fibrosis in IBD patients with thiopurine therapy and other clinical factors, by using transient elastography (TE).

METHODS

In this prospective, international two-center study, included IBD-patients underwent TE measurements. Laboratory results and medication reports, radiology results and historical liver biopsy results were extracted from the patient charts.

RESULTS

Transient elastography results of 168 patients were presented. Moderate and severe fibrosis were detected in 4% (7/168) and 1% (1/168) of the cohort, respectively. Factors contributing to lower liver stiffness were female gender and (historical) exposure to azathioprine. Further, there was a statistical trend towards lower liver stiffness in patients using thiopurines overall (4.7 vs. 5.2kPa, p=0.07). Liver stiffness correlated positively with waist circumference, liver enzyme tests, hemoglobin and 6-methylmercaptopurine concentration and negatively with platelet count.

CONCLUSION

Exposure to thiopurine therapy was not associated with higher liver stiffness, although no clinical difference in severity of fibrosis was detected. Further research should robustly determine the accuracy of TE as an evaluation of liver fibrosis in IBD patients.

Significance of non-alcoholic fatty liver disease in Crohn's disease: A retrospective cohort study

AIM

The prevalence of non-alcoholic fatty liver disease (NAFLD) and Crohn's disease (CD) is increasing. The aim of our study was to evaluate the prevalence of NAFLD in patients with CD, as well as to investigate the effect of NAFLD on the disease course of CD.

METHODS

Our retrospective cohort study included 303 patients who underwent abdominal ultrasound for CD and NAFLD diagnosis at our center between November 2008 and October 2014. Serum C-reactive protein (CRP) level and rate of remission, defined by a score <150 on the Crohn's Disease Activity Index, were compared between CD patients with and without NAFLD, using multivariate logistic regression. The effect of NAFLD on the surgery-free interval was evaluated using Cox proportional hazards models, adjusted for potential demographic confounders.

RESULTS

Non-alcoholic fatty liver disease was diagnosed in 66 (21.8%) patients in our study cohort and was associated with lower CRP levels (0.58 vs. 2.18 mg/dL, P < 0.0001) and a higher rate of remission (75.9% vs. 53.7%, P = 0.0024). Non-alcoholic fatty liver disease was identified as an independent predictor of a negative CRP level (<0.3 mg/dL; odds ratio, 1.85; 95% confidence interval, 1.03-3.37) and higher rate of remission (odds ratio, 2.57; 95% confidence interval, 1.21-5.80). Non-alcoholic fatty liver disease was associated with longer surgery-free interval (log-rank test, P = 0.0035), with NAFLD identified as a positive predictor of surgery-free interval (P = 0.0014).

CONCLUSIONS

Non-alcoholic fatty liver disease may offer a protective effect in patients with CD and could be used as a prognostic marker in patients with CD.

Hepatic manifestations of inflammatory bowel diseases

Inflammatory bowel diseases are associated with various hepatobiliary disorders, reported both in Crohn's disease and ulcerative colitis. They may occur at any moment in the natural course of the disease. The prevalence of liver dysfunction rises from 3% to 50% accordingly to definitions used in different studies. Fatty liver is considered as the most common hepatobiliary complication in inflammatory bowel diseases while primary sclerosing cholangitis is the most specific one. Less frequently, inflammatory bowel diseases-associated hepatobiliary disorders include: autoimmune hepatitis/ primary sclerosing cholangitis overlap syndrome, IgG4-associated cholangiopathy, primary biliary cholangitis, hepatic amyloidosis, granulomatous hepatitis, cholelithiasis, portal vein thrombosis and liver abscess. The spectrum of these manifestations varies according to the type of inflammatory bowel diseases. Treatments of inflammatory bowel diseases may cause liver toxicity, although incidence of serious complications remains low. However, early diagnosis of drug-induced liver injury is of major importance as it affects future clinical management. When facing abnormal liver tests, clinicians should undertake a full diagnostic work-up in order to determine whether the hepatic abnormalities are related to the inflammatory bowel diseases or not. Management of hepatic manifestations in inflammatory bowel diseases usually involves both hepatologists and gastroenterologists because of the complexity of some situations.

Co-existence of non-alcoholic fatty liver disease and inflammatory bowel disease: A review article

Emerging data have highlighted the co-existence of non-alcoholic fatty liver disease (NAFLD) and inflammatory bowel disease; both of which are increasingly prevalent disorders with significant complications and impact on future health burden. Cross-section observational studies have shown widely variable prevalence rates of co-existing disease, largely due to differences in disease definition and diagnostic tools utilised in the studies. Age, obesity, insulin resistance and other metabolic conditions are common risks factors in observational studies. However, other studies have also suggested a more dominant role of inflammatory bowel disease related factors such as disease activity, duration, steroid use and prior surgical intervention, in the development of NAFLD. This suggests a potentially more complex pathogenesis and relationship between the two diseases which may be contributed by factors including altered intestinal permeability, gut dysbiosis and chronic inflammatory response. Commonly used immunomodulation agents pose potential hepatic toxicity, however no definitive evidence exist linking them to the development of hepatic steatosis, nor are there any data on the impact of therapy and prognosis in patient with co-existent diseases. Further studies are required to assess the impact and establish appropriate screening and management strategies in order to allow early identification, intervention and improve patient outcomes.

Incidence and Predictors of Nonalcoholic Fatty Liver Disease by Serum Biomarkers in Patients with Inflammatory Bowel Disease

BACKGROUND

Patients with inflammatory bowel disease (IBD) are at high risk for non-alcoholic fatty liver disease (NAFLD). Longitudinal data on incident NAFLD are lacking. We employed non-invasive methods to study incidence and predictors of NAFLD.

METHODS

This was a retrospective study of IBD patients without known liver disease followed at IBD clinic of McGill University. NAFLD was defined as Hepatic Steatosis Index (HSI) ≥36 and absence of alcohol intake. Advanced liver fibrosis was diagnosed by FIB-4 ≥2.67. Active IBD was defined as partial Mayo score ≥3 for ulcerative colitis, Harvey Bradshaw Index ≥ 5 or flare during follow-up. Kaplan-Meier and Cox regression analyses were used to investigate incidence and predictors of NAFLD development.

RESULTS

Three hundred twenty-one consecutive patients (median age 33.7 yr, 47% males) were observed for a median of 3.2 years (interquartile range 1.5-6). Over 1181.2 persons-year (PY), 108 (33.6%) patients developed NAFLD, accounting for an incidence rate of 9.1/100 PY (95% confidence interval [CI], 7.4-10.9). 7 (2.2%) patients developed advanced liver fibrosis, accounting for an incidence rate of 0.5/100 PY (95% CI, 0.2-1.1). Development of NAFLD was predicted by disease activity (adjusted hazard ratio [aHR] = 1.58; 95% CI, 1.08-2.33, P = 0.02), disease duration (aHR = 1.12; 95% CI, 1.03-1.23, P = 0.01), and prior surgery for IBD (aHR = 1.34; 95% CI, 1.04-1.74, P = 0.02).

CONCLUSIONS

NAFLD is a frequent comorbidity in patients with IBD. These patients can also develop advanced liver fibrosis. Disease activity, duration of IBD and prior surgery are predictors of NAFLD development. This should represent one more incentive to achieve and maintain early clinical remission. Further prospective studies are of interest.