A common genetic variant near MBOAT7 (rs641738C>T) has been previously associated with hepatic fat and advanced histology in NAFLD; however, these findings have not been consistently replicated in the literature. We aimed to establish whether rs641738C>T is a risk factor across the spectrum of NAFLD and to characterise its role in the regulation of related metabolic phenotypes through a meta-analysis. We performed a meta-analysis of studies with data on the association between rs641738C>T genotype and liver fat, NAFLD histology, and serum alanine aminotransferase (ALT), lipids or insulin. These included directly genotyped studies and population-level data from genome-wide association studies (GWAS). We performed a random effects meta-analysis using recessive, additive and dominant genetic models. Data from 1,066,175 participants (9,688 with liver biopsies) across 42 studies were included in the meta-analysis. rs641738C>T was associated with higher liver fat on CT/MRI (+0.03 standard deviations [95% CI 0.02–0.05], pz = 4.8×10–5) and diagnosis of NAFLD (odds ratio [OR] 1.17 [95% CI 1.05–1.3], pz = 0.003) in Caucasian adults. The variant was also positively associated with presence of advanced fibrosis (OR 1.22 [95% CI 1.03–1.45], pz = 0.021) in Caucasian adults using a recessive model of inheritance (CC + CT vs. TT). Meta-analysis of data from previous GWAS found the variant to be associated with higher ALT (pz = 0.002) and lower serum triglycerides (pz = 1.5×10–4). rs641738C>T was not associated with fasting insulin and no effect was observed in children with NAFLD. Our study validates rs641738C>T near MBOAT7 as a risk factor for the presence and severity of NAFLD in individuals of European descent. Fatty liver disease is a common condition where fat builds up in the liver, which can cause liver inflammation and scarring (including ‘cirrhosis’). It is closely linked to obesity and diabetes, but some genes are also thought to be important. We did this study to see whether one specific change (‘variant’) in one gene (‘MBOAT7’) was linked to fatty liver disease. We took data from over 40 published studies and found that this variant near MBOAT7 is linked to more severe fatty liver disease. This means that drugs designed to work on MBOAT7 could be useful for treating fatty liver disease.

Previously, we identified needle-like and filamentous, putatively “anhydrous” cholesterol crystallization in vitro at very low phospholipid concentrations in model and native biles. Our aim now was to address whether spontaneous gallstone formation occurs in Mdr2 (Abcb4) knockout mice that are characterized by phospholipid-deficient bile. Biliary phenotypes and cholesterol crystallization sequences in fresh gallbladder biles and non-fixed liver sections were determined by direct and polarizing light microscopy. The physical chemical nature and composition of crystals and stones were determined by sucrose density centrifugation and before mass and infrared spectroscopy. Gallbladder biles of Mdr2 ^−/− mice precipitate needle-like cholesterol crystals at 12 weeks of age on chow. After 15 weeks, more than 50% of Mdr2 ^−/− mice develop gallbladder stones, with female mice displaying a markedly higher gallstone-susceptibility. Although gallbladder biles of Mdr2 ^−/− mice contain only traces (≤ 1.1 mM) of phospholipid and cholesterol, they become supersaturated with cholesterol and plot in the left 2-phase zone of the ternary phase diagram, consistent with “anhydrous” cholesterol crystallization. Furthermore, more than 40% of adult female Mdr2 ^−/− mice show intra- and extrahepatic bile duct stones. In conclusion, spontaneous gallstone formation is a new consistent feature of the Mdr2 ^−/− phenotype. The Mdr2 ^−/− mouse is therefore a model for low phospholipid-associated cholelithiasis recently described in humans with a dysfunctional mutation in the orthologous ABCB4 gene. The mouse model supports the concept that this gene is a monogenic risk factor for cholesterol gallstones and a target for novel therapeutic strategies. (Hepatology 2004;39:117-128.)

Spontaneous bacterial peritonitis (SBP), a severe complication in patients with advanced liver cirrhosis, has been attributed to bacterial translocation from the intestine. Variants of the NOD2 (nucleotide-binding oligomerization domain containing 2) gene have been associated with impaired mucosal barrier function in Crohn disease. We hypothesized that the risk of acquiring SBP is increased in patients with cirrhosis carrying NOD2 variants. We recruited 150 nonselected patients with liver cirrhosis and ascites admitted to our unit, monitored survival, and recorded the development of SBP prospectively and retrospectively. SBP was defined as the presence of polymorphonuclear neutrophil (PMN) cells >250 per μL of ascitic fluid. Patients were genotyped for the NOD2 variants p.R702W, p.G908R, and c.3020insC. During a median follow-up of 155 days, 54 patients (36%) died and SBP was diagnosed in 30 patients (20%). The occurrence of SBP was increased significantly (P = 0.008) in carriers of NOD2 variants (odds ratio [OR] = 3.06). Retrospectively, SBP was observed in 22 additional patients, and the combined prospective and retrospective analysis substantiated the association between NOD2 and SBP (P = 0.004; OR = 2.98). Of note, carriers of NOD2 risk alleles showed a significantly (P = 0.007) reduced mean survival time (274 days) in comparison to patients with wildtype genotypes (395 days). Conclusion: Common NOD2 variants linked previously to impaired mucosal barrier function may be genetic risk factors for death and SBP. These findings might serve to identify patients with cirrhotic ascites eligible for preemptive antibiotic treatment. (HEPATOLOGY 2010.)

Nucleos(t)ide analogues (NUCs) are the standard and mostly lifelong treatment for chronic HBeAg-negative hepatitis B, as functional cure (loss of HBsAg) is rarely achieved. Discontinuation of NUC treatment may lead to functional cure; however, to date, the evidence for this has been based on small or non-randomized clinical trials. The STOP-NUC trial was designed with the aim of increasing the HBsAg loss rate using a NUC treatment interruption approach. In this multicenter, randomized-controlled trial, 166 HBeAg-negative patients with chronic hepatitis B on continuous long-term NUC treatment, with HBV DNA <172 IU/ml (1,000 copies/ml) for ≥4 years, were randomized to either stop (Arm A) or continue NUC treatment (Arm B) for a 96-week observation period. In total, 158 patients were available for final analysis, 79 per arm. The primary endpoint was sustained HBsAg loss up to week 96. Our study met its primary objective by demonstrating HBsAg loss in eight patients (10.1%, 95% CI 4.8%-19.5%) in Arm A and in no patient in Arm B (p = 0.006). Among patients with baseline HBsAg levels 1 log IU/ml was observed in 16 patients (20.3%) in Arm A and in one patient (1.3%) in Arm B. No serious adverse events related to treatment cessation occurred. Cessation of NUC treatment was associated with a significantly higher rate of HBsAg loss than continued NUC treatment, which was largely restricted to patients with end of treatment HBsAg levels <1,000 IU/ml. As HBeAg-negative patients with chronic hepatitis B on nucleos(t)ide analogues (NUCs) rarely achieve functional cure, treatment is almost always lifelong. The STOP-NUC trial was conducted to investigate whether discontinuing long-term NUC treatment can increase the cure rate. We found that some patients achieved functional cure after stopping NUCs, which was especially pronounced in patients with HBsAg levels <1,000 at the end of NUC treatment, and that many did not need to resume therapy. The results of the Stop-NUC trial provide evidence for the concept of stopping NUC treatment as a therapeutic option that can induce functional cure.