Disruption of gut barrier integrity and host-microbiome interactions underlie MASLD severity in patients with type-2 diabetes mellitus

Aberration of the "gut-liver axis" contributes to the development and progression of metabolic dysfunction-associated steatotic liver disease (MASLD). Here, we use multi-omics to analyze the gut microbiota composition and metabolic profile of patients with type-2 diabetes mellitus (T2DM). T2DM patients were screened for liver disease by blood tests, ultrasound, and liver stiffness measurements. Stool microbiota was analyzed by 16S rRNA gene sequencing; metabolomic profiling by Nuclear Magnetic Resonance spectroscopy and Ultra-High Performance-Mass Spectrometry. Microbiome and metabolic signatures were analyzed in the whole cohort and in matched subsets to identify signatures specific for steatosis (MASLD±) or fibrosis (Fibrosis±). Gut permeability was assessed in-vitro using monolayers of MDCK cells and trans-epithelial electric resistance (TEER). Cytokine profile was assessed in serum and stools.Overall, 285 patients were enrolled: 255 serum, 252 urine and 97 stool samples were analyzed. Anaeroplasma and Escherichia/Shigella ASVs were higher, while Butyricicoccus ASVs were lower in those with normal liver. In MASLD±, Butyricicoccus ASV was significantly higher in those with steatosis. In the Fibrosis±, Butyricicoccus ASV was significantly lower in those with fibrosis. Glycochenodeoxycholic acid-3-sulfate (G-UDCA-3S) appeared to be higher in MASLD with fibrosis. Fecal water from patients with MASLD and fibrosis caused the greatest drop in the TEER vs those with normal liver; this was reversed with protease inhibitors. Finally, fecal IL-13 was lower in MASLD with fibrosis. We identified microbiome signatures which were specific for steatosis and fibrosis and independent of other metabolic risk factors. Moreover, we conclude that protease-related gut permeability plays a role in those MASLD patients with fibrosis, and that disease progression is linked to a gut-liver axis which is at least partially independent of T2DM.

Biochemical criteria at 1 year are not robust indicators of response to ursodeoxycholic acid in early primary biliary cirrhosis: results from a 29-year cohort study

BACKGROUND

In primary biliary cirrhosis (PBC), biochemical criteria at 1 year are considered surrogates of response to ursodeoxycholic acid (UDCA). However, due to the slow natural history of PBC, evaluation at 1 year may be suboptimal to assess the therapeutic response, particularly in early disease.

AIM

To determine whether evaluation of biochemical criteria at 1 year is a reliable surrogate of UDCA response in early PBC.

METHODS

We analysed the prospectively collected data of 215 patients (untreated = 129; UDCA-treated = 86) with early PBC (normal baseline bilirubin/albumin) and a median follow-up of 8 years (range: 1-29.1). The 1-year attainment rates of the Barcelona, Paris-I, Paris-II and Toronto definitions, and their predictive relevance for a poor outcome (death, transplantation, complications of cirrhosis), were assessed either as a result of UDCA or no treatment. Independent associations with attaining each UDCA response definition were identified by multivariate analysis.

RESULTS

Untreated patients displayed 1-year biochemical features compatible with 'treatment response' at rates (Barcelona: 36.4%, Paris-I: 66.7%, Toronto: 59.7%, Paris-II: 40.3%) similar to those obtained under UDCA. Depending on the definition, baseline ALP≤3xULN (OR: 4.80-35.90), AST≤2xULN (OR: 5.63-9.34) and early histological stage (OR: 3.67-3.87) were the stronger predictors for attaining the criteria. UDCA treatment was associated with attaining Barcelona (OR = 2.16) and Paris-II (OR = 2.84), but not Paris-I, and not Toronto definition when excluding late histological cases. Paris-I criteria were significantly predictive of long-term outcomes (HR = 2.83) in untreated patients.

CONCLUSIONS

In early PBC, biochemical criteria at 1 year reflect severity of the disease rather than the therapeutic response to UDCA.

CXCR3 axis in patients with primary biliary cirrhosis: a possible novel mechanism of the effect of ursodeoxycholic acid

The CXC chemokines, monokine induced by interferon (IFN)-gamma (MIG) (CXCL9), IFN-gamma-induced protein 10 (IP-10) (CXCL10) and IFN-inducible T cell alpha chemoattractant (I-TAC) (CXCL11), are known to attract CXCR3- (CXCR3A and CXCR3B) T lymphocytes. We investigated MIG, IP-10 and I-TAC mRNAs expression by semi-quantitative multiplex reverse transcription-polymerase chain reaction (RT-PCR) in liver biopsies obtained from patients with a first diagnosis of primary biliary cirrhosis [(PBC) = 20] compared to patients with normal liver biopsy [normal controls (NCs) = 20]. Chemokine production was assessed by enzyme-linked immunosorbent assay (ELISA) in serum. Measurements were repeated 6 months after ursodeoxycholic acid (UDCA) treatment in PBC patients. CXCR3A and CXCR3B mRNAs expression was examined in immunomagnetically sorted CD3(+) peripheral blood lymphocytes (PBL) pre- and post-treatment by RT-PCR. Flow cytometry was used to evaluate the expression of CXCR3(+) PBLs of NCs and PBC patients. A marked mRNA expression of MIG and IP-10 was found in PBC patients. I-TAC mRNA was not detected. In serum of PBC patients there was a significant increase of MIG and IP-10 compared to NCs. Interestingly, there was a significant reduction of these proteins in patients' serum after UDCA treatment. I-TAC was not statistically different between groups. CXCR3A mRNA expression was found in PBLs from PBC patients as well as in NCs. CXCR3B mRNA was expressed in four of 20 (19%) NCs and 20 of 20 PBC patients. Flow cytometry revealed a significantly lower CXCR3 expression in NCs (13·5%) than in PBC (37·2%), which was reduced (28·1%, P < 0·01) after UDCA administration. These data suggest a possible role for CXCR3-binding chemokines and their receptor in the aetiopathogenetic recruitment of lymphocytes in PBC and a new mechanism of action for UDCA.

Increased expression of chemokine receptor CCR3 and its ligands in ulcerative colitis: the role of colonic epithelial cells in in vitro studies

Human colonic epithelial cells express T helper type 1 (Th1)-associated chemoattractants, yet little is known about the production of Th2-associated chemoattractants. CCL11/eotaxin-1, CCL24/eotaxin-2 and CCL26/eotaxin-3 are known to attract CCR3-expressing, Th2-polarized lymphocytes. We studied constitutive and inflammation-induced expression and production of CCR3 together with its ligands in the colon and peripheral blood of patients with inflammatory bowel disease (IBD) by flow cytometry, reverse transcription–polymerase chain reaction (RT–PCR) and enzyme-linked immunosorbent assay (ELISA). We further defined the regulated expression of these chemokines by RT–PCR and ELISA using cultured human epithelial cell lines. A higher fraction of peripheral T lymphocytes were found to be positive for CCR3 in patients with ulcerative colitis (UC) compared to Crohn’s disease (CD), while almost no CCR3(+) T cells were found in normal controls (NC). Similarly, higher and more frequent expression of CCR3 was observed in colonic biopsies from patients with UC, regardless of the disease activity, when compared to CD or NCs. Serum CCL11/eotaxin-1 was increased significantly in UC (306 ± 87 pg/ml) and less so in CD (257 ± 43 pg/ml), whereas CCL24/eotaxin-2, and CCL26/eotaxin-3 were increased only in UC. Colonic expression of the three chemokines was minimal in NCs but high in inflammatory bowel diseases (especially UC) and was independent of disease activity. Th2, and to a lesser extent Th1, cytokines were able to induce expression and production of all three eotaxins from colonic epithelial cells in culture. CCR3 and ligands over-expression would appear to be a characteristic of UC. The production of CCR3 ligands by human colonic epithelial cells suggests further that epithelium can play a role in modulating pathological T cell-mediated mucosal inflammation.

A simple, noninvasive test for the diagnosis of liver fibrosis in patients with hepatitis C recurrence after liver transplantation

Recurrent hepatitis C is a common cause of graft loss in patients undergoing liver transplantation, and serial protocol liver biopsies have been used to identify patients at risk of graft loss from rapid fibrosis progression. The aim of this study was to derive a simple noninvasive index to predict fibrosis in patients with recurrent hepatitis C post-transplant. A retrospective study was performed assessing serial liver biopsies for post-transplant chronic hepatitis C infection. One hundred eighty-five patients were included in the analysis; median age 53 years (interquartile range 48-59) and 140 (76%) were male. Liver histology showed 53 (29%) had Ishak fibrosis stages F0/F1, 31 (17%) had F2, 29 (16%) had F3, 19 (10%) had F4 and 53 (29%) had F5/F6. The London Transplant Centres' (LTC) score was derived combining aspartate aminotransferase (AST IU/L), time from liver transplant (TFLT months), international normalized ratio and platelets. Diagnostic accuracy of the LTC score was assessed using area under receiver-operating characteristic (ROC) curves. The area under the ROC curve for moderate fibrosis (F >or= 2) was 0.78 (95% CI, 0.70-0.86; P < 0.0001), for advanced fibrosis (F4-6) was 0.80 (95% CI, 0.72-0.87; P < 0.0001) and for cirrhosis was 0.80 (95% CI, 0.72-0.88; P < 0.0001). An optimal cut-off value of 6.3 distinguished patients with no or mild fibrosis (F <or= 1) odds ratio 10.8 (95% CI, 5.1-22.9); P < 0.0001), sensitivity 88%, specificity 60%, negative predictive value 67% and positive predictive value 84%. The LTC score can identify patients with Hepatitis C virus recurrence following liver transplant with a low risk of significant fibrosis, thus avoiding the need for protocol biopsy.

Prospective comparison of Fibroscan, King's score and liver biopsy for the assessment of cirrhosis in chronic hepatitis C infection

Historically, liver biopsy (LB) was the sole method to evaluate the severity of hepatic fibrosis in patients with chronic hepatitis C infection. However, LB is expensive and associated with a risk of severe complications. Therefore, noninvasive tests have been developed to assess the severity of liver fibrosis. The accuracy of Fibroscan (FS) and King's score (KS) was evaluated individually and in combination using liver histology as the reference standard. One hundred and eighty-seven patients were identified who had undergone a biopsy with a diagnosis of chronic hepatitis C virus (HCV) mono-infection (HCV RNA-positive by RT-PCR), attending King's College Hospital (n = 88) or the Royal Free Hospital (n = 99) (London) between May 2006 and December 2007. Liver fibrosis was scored using the Ishak method; significant fibrosis was defined as Ishak fibrosis stage F3-F6, and cirrhosis defined as Ishak fibrosis F5-F6. The diagnostic accuracy of each test was assessed by area under receiver operator characteristic curves (AUROC). Median age was 49 years (43-54) and 115 (61%) were male. The AUROC for FS, KS and FS + KS for the diagnosis of Ishak F3-F6 were 0.83, 0.82 and 0.85, respectively and for the diagnosis of cirrhosis (>or=F5) were 0.96, 0.89 and 0.93, respectively. The negative predictive values for the diagnosis of cirrhosis using the optimal cut-off results for fibrsocan (10.05 kPa), KS (24.3) and the two combined (26.1) were 98%, 91% and 94%, respectively. The noninvasive markers and, particularly, FS were effective tests for the prediction of cirrhosis in chronic hepatitis C. Both KS and FS also had clinical utility for the prediction of Ishak fibrosis stages F3-F6.

Fibrosis staging in chronic hepatitis C: analysis of discordance between transient elastography and liver biopsy

In chronic hepatitis C, transient elastography (TE) accurately identifies cirrhosis, but its ability to assess significant fibrosis (Metavir > or = F2) is variable. Constitutional and liver disease-related factors may influence TE and here we examined the variables associated with differences. Three hundred consecutive hepatitis C virus (HCV)-RNA positive patients had biochemical tests, TE and a biopsy performed on the same day. The Dale model was used to identify the variables associated with discordance between biopsy and elastography results. In 97 patients (34.2%), TE and histological assessment were discordant. Seventy-six of 286 (26.6%) had stage > or =F2 and TE < 7.1 kPa (false negative); 21 of 286 (7.3%) had stage <F2 and TE > or = 7.1 kPa (false positive). No patient with discordant results had cirrhosis. By Dale model, aspartate aminotransferase (AST) was found to be the unique variable significantly related (P = 0.046) with discordance between biopsy and TE. Discordance rate was 43.4% (82 patients) with AST < 1.5 x UNL vs 25.8% (25 patients) with AST > or = 1.5 x UNL (P = 0.004). False negative rate was 43.4 (82 patients) with AST < 1.5 x UNL vs 17.1% (13 patients) with AST > or = 1.5 x UNL (P < 0.001). Areas under the receiver operating characteristic (AUROC) for F > or = 2, according to AST < 1.5 x UNL vs > or = 1.5 x UNL were 0.738 (95% CI: 0.683-0.812) and 0.854(95% CI: 0.754-0.907). Transient elastography is not adequate on its own to rule out or to rule in significant fibrosis, as it is influenced by major variations in biochemical activity of liver disease. Liver stiffness, at low levels of AST, can underestimate fibrosis.

Pegylated-interferon and ribavirin in liver transplant candidates and recipients with HCV cirrhosis: systematic review and meta-analysis of prospective controlled studies

Pegylated interferon with ribavirin (Peg/R) is the most effective therapy for chronic hepatitis C virus (HCV) but its utility and effectiveness after liver transplantation has been difficult to assess. We evaluated efficacy, tolerability, and safety of Peg/R in liver transplant candidates and recipients with HCV cirrhosis. We searched medical databases and conference proceedings between January 1999 and January 2008 selecting randomized and nonrandomized studies. Primary end points meta-analytically were: (1) sustained viral response (SVR) and (2) histological response. Secondary end points were: (1) treatment discontinuation, (2) mortality, and (3) rejection episodes. Pegylated interferons using either 1-1.5 mcg/kg of pegylated interferon alpha-2b or 180 microg (pegylated interferon alpha-2a combined with ribavirin 800-1200 mg/day were the most effective compared to any other regimen or no therapy. In three pretransplant studies the median SVR was 19.6% (19.6-50%). In six postransplant studies where a meta-analysis was done the cumulative risk difference in SVR was 0.31% (95% CI, 0.18-0.44, p < 0.001). However histological response was not significantly better compared to no therapy or other antiviral regimens. There were no significant differences in discontinuation of therapy, acute or chronic rejection or mortality between optimal Peg/R vs no treatment or other regimens. Hence pegylated interferon plus ribavirin in full doses is effective pre and post transplant but has a low SVR rate. To date no significant histological improvement has been reported.

Muscle cramps in cirrhosis: the therapeutic value of quinine. Is it underused?

Muscle cramps are a common and recurring symptom in patients with cirrhosis. Although, the pathophysiology has not been specifically studied in cirrhosis, this is thought to be the same for cramps in general, originating in the motorneurone, with high frequency firing of motor unit action potentials. However precise pathophysiological mechanisms are not known. Risk factors in cirrhosis have been little studied. Neither aetiology, nor pre-ascitic or ascitic stage, nor electrolyte disturbances, nor use of diuretic therapy has been found to have a statistical association with cramps in patients with cirrhosis. Effective treatments, from this literature review, are albumin, which however is expensive and has little applicability as preventative therapy and oral quinine or quinidine. Quinine is little used in Italy but licensed in the UK for the therapy of muscle cramps. There is evidence for the efficacy of quinine in patients without cirrhosis and in healthy subjects. In cirrhosis quinidine (isomer of quinine) has also been shown to be effective versus placebo. Its major effect is in the prevention of cramps. More widespread use of quinine and further studies are needed, particularly in Italy and other countries, in which its use has been limited, as it is effective therapy in many patients with cirrhosis.

Models for non-alcoholic fatty liver disease: a link with vascular risk

Non alcoholic fatty liver disease (NAFLD) is often part of the metabolic syndrome which includes central obesity, dyslipidaemia, insulin resistance/type 2 diabetes mellitus and hypertension. In turn, NAFLD may be associated with an increased vascular risk. Several experimental models which express histological steatosis or steatohepatitis with fibrosis have been described. This review identifies those models of NAFLD with features of vascular risk.

The transjugular route: the key hole to the liver world

Portal hypertensive complications are major causes of morbidity and mortality in patients with liver cirrhosis. The advent of the transjugular route with its minimal access allows non-surgical management of portal hypertension, therapy of venous complications of liver transplantation, monitoring of therapy for portal hypertension, hepatic venous pressure gradient and is also the major route to treat hepatic venous obstruction syndromes. In addition, the transjugular route is a safe route to perform a liver biopsy (transjugular liver biopsy) and allows retrograde evaluation of the portal vein. All these procedures can be combined in the same session. These hepatic interventional radiological skills should be incorporated into the expertise of the liver team in specialised hepatological centres, particularly in liver transplant centres as they are especially useful in improving outcomes of cirrhotic patients on the liver transplantation waiting list. A limitation in achieving this goal, could be the number of experienced radiologists, but hepatologists can be trained, at least for the most simple procedures (transjugular liver biopsy and hepatic venous pressure gradient). This would allow wider applicability and use of these diagnostic and therapeutic techniques, all through a 2 mm hole in the neck--the key hole to the liver world.

Ciprofloxacin inhibits cytokine-induced nitric oxide production in human colonic epithelium

BACKGROUND

The fluoroquinolone ciprofloxacin is a broad-spectrum antibiotic that has been used in the treatment of inflammatory bowel diseases. There is evidence that quinolones have immunomodulating activities via the regulation of cytokine production.

MATERIALS AND METHODS

We investigated the effect of ciprofloxacin on the nitric oxide (NO) production by colonic epithelium. HT-29 cells and colonic biopsies from patients (n = 4) with ulcerative colitis (UC) and normal controls (n = 4) were cultured with various concentrations of ciprofloxacin (10-100 microg mL(-1)) in the presence and absence of pro-inflammatory cytokines. The production of NO was measured in culture supernatants with a spectrophotometric method and inducible nitric oxide synthase (iNOS) mRNA expression was examined by reverse transcription-polymerase chain reaction (RT-PCR).

RESULTS

Ciprofloxacin did not have any effect on the basal NO production by HT-29 cells. In contrast, ciprofloxacin significantly (P < 0.001) inhibited the pro-inflammatory cytokines (interleukin-1alpha + tumour necrosis factor-alpha + interferon-gamma)-induced NO production in HT-29, in a concentration-dependent manner, via the inhibition of the cytokine-induced iNOS mRNA expression. Wortmannin produced a concentration related reversal of the inhibitory effect of ciprofloxacin at both iNOS mRNA expression and NO production in HT-29 cells. A similar inhibitory effect of ciprofloxacin on the cytokine-induced NO production and iNOS mRNA expression was detected in vitro in cultures of normal colonic tissue. In addition, ciprofloxacin significantly inhibited the NO production and iNOS mRNA expression in cultures of colonic tissue from ulcerative colitis patients, in a concentration-dependent manner.

CONCLUSIONS

These data suggest that ciprofloxacin, in addition to its antimicrobial role, might have an immunoregulatory effect on intestinal inflammation, via the modulation of inflammatory mediators.