Hepatic and adipose tissue transcriptome analysis highlights a commonly deregulated autophagic pathway in severe MASLD.

OBJECTIVE: The incidence of metabolic dysfunction-associated steatotic liver disease (MASLD) is rapidly ramping up due to the spread of obesity, which is characterized by expanded and dysfunctional visceral adipose tissue (VAT). Previous studies have investigated the hepatic transcriptome across MASLD, whereas few studies have focused on VAT. METHODS: We performed RNA sequencing in 167 hepatic samples from patients with obesity and in a subset of 79 matched VAT samples. Circulating cathepsin D (CTSD), a lysosomal protease, was measured by ELISA, whereas the autophagy-lysosomal pathway was assessed by Western blot in hepatic and VAT samples (n = 20). RESULTS: Inflammation, extracellular matrix remodeling, and mitochondrial dysfunction were upregulated in severe MASLD in both tissues, whereas autophagy and oxidative phosphorylation were reduced. Tissue comparative analysis revealed 13 deregulated genes, including CTSD, which showed the most robust diagnostic accuracy in discriminating mild and severe MASLD. CTSD expression correlated with circulating protein, whose increase was further validated in 432 histologically characterized MASLD patients, showing a high accuracy in foreseeing severe liver injury. In addition, the assessment of serum CTSD increased the performance of fibrosis 4 in diagnosing advanced disease. CONCLUSIONS: By comparing the hepatic and VAT transcriptome during MASLD, we refined the concept by which CTSD may represent a potential biomarker of severe disease.

A novel gene signature to diagnose MASLD in metabolically unhealthy obese individuals.

Visceral adipose tissue (VAT) contributes to metabolic dysfunction-associated steatotic liver disease (MASLD), releasing lipogenic substrates and cytokines which promote inflammation. Metabolic healthy obese individuals (MHO) may shift towardsunhealthy ones (MUHO) who develop MASLD, although the mechanisms are still unexplained. Therefore, we aimed to identify dysfunctional pathways and transcriptomic signatures shared by liver and VAT and to outline novel obesity-related biomarkers which feature MASLD in MUHO subjects, at higher risk of progressive liver disease and extrahepatic comorbidities. We performed RNA-sequencing in 167 hepatic samples and in a subset of 79 matched VAT, stratified in MHO and MUHO. A validation analysis was performed in hepatic samples and primary adipocytes from 12 bariatric patients, by qRT-PCR and western blot. We identified a transcriptomic signature that discriminate MUHO vs MHO, including 498 deregulated genes in liver and 189 in VAT. According to pathway and network analyses, oxidative phosphorylation resulted the only significantly downregulated pathway in both tissues in MUHO subjects. Next, we highlighted 5 genes commonly deregulated in liver and VAT, encompassing C6, IGF1, OXA1L, NDUFB11 and KLHL5 and we built a tissue-related score by integrating their expressions. Accordingly to RNAseq data, serum levels of C6 and IGF1, which are the only secreted proteins among those included in the gene signature were downregulated in MUHO vs MHO. Finally, the expression pattern of this 5-genes was confirmed in hepatic and VAT samples. We firstly identified the liver and VAT transcriptional phenotype of MUHO and a gene signature associated with the presence of MASLD in these at risk individuals.

The I148M PNPLA3 variant mitigates niacin beneficial effects: How the genetic screening in non-alcoholic fatty liver disease patients gains value.

Background: The PNPLA3 p.I148M impact on fat accumulation can be modulated by nutrients. Niacin (Vitamin B3) reduced triglycerides synthesis in in vitro and in vivo NAFLD models. Objectives: In this study, we aimed to investigate the niacin-I148M polymorphism crosstalk in NAFLD patients and examine niacin's beneficial effect in reducing fat by exploiting hepatoma cells with different PNPLA3 genotype. Design: We enrolled 172 (Discovery cohort) and 358 (Validation cohort) patients with non-invasive and histological diagnosis of NAFLD, respectively. Dietary niacin was collected from food diary, while its serum levels were quantified by ELISA. Hepatic expression of genes related to NAD metabolism was evaluated by RNAseq in bariatric NAFLD patients (n = 183; Transcriptomic cohort). Hep3B (148I/I) and HepG2 (148M/M) cells were silenced (siHep3B) or overexpressed (HepG2I148+ ) for PNPLA3, respectively. Results: In the Discovery cohort, dietary niacin was significantly reduced in patients with steatosis ≥ 2 and in I148M carriers. Serum niacin was lower in subjects carrying the G at risk allele and negatively correlated with obesity. The latter result was confirmed in the Validation cohort. At multivariate analysis, the I148M polymorphism was independently associated with serum niacin, supporting that it may be directly involved in the modulation of its availability. siHep3B cells showed an impaired NAD biosynthesis comparable to HepG2 cells which led to lower niacin efficacy in clearing fat, supporting a required functional protein to guarantee its effectiveness. Conversely, the restoration of PNPLA3 Wt protein in HepG2I148+ cells recovered the NAD pathway and improved niacin efficacy. Finally, niacin inhibited de novo lipogenesis through the ERK1/2/AMPK/SIRT1 pathway, with the consequent SREBP1-driven PNPLA3 reduction only in Hep3B and HepG2I148M+ cells. Conclusions: We demonstrated a niacin-PNPLA3 I148M interaction in NAFLD patients which possibly pave the way to vitamin B3 supplementation in those with a predisposing genetic background.

Mboat7 down-regulation by hyper-insulinemia induces fat accumulation in hepatocytes.

BACKGROUND: Naturally occurring variation in Membrane-bound O-acyltransferase domain-containing 7 (MBOAT7), encoding for an enzyme involved in phosphatidylinositol acyl-chain remodelling, has been associated with fatty liver and hepatic disorders. Here, we examined the relationship between hepatic Mboat7 down-regulation and fat accumulation. METHODS: Hepatic MBOAT7 expression was surveyed in 119 obese individuals and in experimental models. MBOAT7 was acutely silenced by antisense oligonucleotides in C57Bl/6 mice, and by CRISPR/Cas9 in HepG2 hepatocytes. FINDINGS: In obese individuals, hepatic MBOAT7 mRNA decreased from normal liver to steatohepatitis, independently of diabetes, inflammation and MBOAT7 genotype. Hepatic MBOAT7 levels were reduced in murine models of fatty liver, and by hyper-insulinemia. In wild-type mice, Mboat7 was down-regulated by refeeding and insulin, concomitantly with insulin signalling activation. Acute hepatic Mboat7 silencing promoted hepatic steatosis in vivo and enhanced expression of fatty acid transporter Fatp1. MBOAT7 deletion in hepatocytes reduced the incorporation of arachidonic acid into phosphatidylinositol, consistently with decreased enzymatic activity, determining the accumulation of saturated triglycerides, enhanced lipogenesis and FATP1 expression, while FATP1 deletion rescued the phenotype. INTERPRETATION: MBOAT7 down-regulation by hyper-insulinemia contributes to hepatic fat accumulation, impairing phosphatidylinositol remodelling and up-regulating FATP1. FUNDING: LV was supported by MyFirst Grant AIRC n.16888, Ricerca Finalizzata Ministero della Salute RF-2016-02,364,358, Ricerca corrente Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico; LV and AG received funding from the European Union Programme Horizon 2020 (No. 777,377) for the project LITMUS-"Liver Investigation: Testing Marker Utility in Steatohepatitis". MM was supported by Fondazione Italiana per lo Studio del Fegato (AISF) 'Mario Coppo' fellowship.

Liver transcriptomics highlights interleukin-32 as novel NAFLD-related cytokine and candidate biomarker.

OBJECTIVE: Efforts to manage non-alcoholic fatty liver disease (NAFLD) are limited by the incomplete understanding of the pathogenic mechanisms and the absence of accurate non-invasive biomarkers. The aim of this study was to identify novel NAFLD therapeutic targets andbiomarkers by conducting liver transcriptomic analysis in patients stratified by the presence of the PNPLA3 I148M genetic risk variant. DESIGN: We sequenced the hepatic transcriptome of 125 obese individuals. 'Severe NAFLD' was defined as the presence of steatohepatitis, NAFLD activity score ≥4 or fibrosis stage ≥2. The circulating levels of the most upregulated transcript, interleukin-32 (IL32), were measured by ELISA. RESULTS: Carriage of the PNPLA3 I148M variant correlated with the two major components of hepatic transcriptome variability and broadly influenced gene expression. In patients with severe NAFLD, there was an upregulation of inflammatory and lipid metabolism pathways. IL32 was the most robustly upregulated gene in the severe NAFLD group (adjusted p=1×10-6), and its expression correlated with steatosis severity, both in I148M variant carriers and non-carriers. In 77 severely obese, and in a replication cohort of 160 individuals evaluated at the hepatology service, circulating IL32 levels were associated with both NAFLD and severe NAFLD independently of aminotransferases (p<0.01 for both). A linear combination of IL32-ALT-AST showed a better performance than ALT-AST alone in NAFLD diagnosis (area under the curve=0.92 vs 0.81, p=5×10-5). CONCLUSION: Hepatic IL32 is overexpressed in NAFLD, correlates with hepatic fat and liver damage, and is detectable in the circulation, where it is independently associated with the presence and severity of NAFLD.

PCSK7 gene variation bridges atherogenic dyslipidemia with hepatic inflammation in NAFLD patients.

Dyslipidemia and altered iron metabolism are typical features of nonalcoholic fatty liver disease (NAFLD). Proprotein convertase subtilisin/kexin type 7 (PCSK7) gene variation has been associated with circulating lipids and liver damage during iron overload. The aim of this study was to examine the impact of the PCSK7 rs236918 variant on NAFLD-related traits in 1,801 individuals from the Liver Biopsy Cohort (LBC), 500,000 from the UK Biobank Cohort (UKBBC), and 4,580 from the Dallas Heart Study (DHS). The minor PCSK7 rs236918 C allele was associated with higher triglycerides, aminotransferases, and hepatic inflammation in the LBC (P < 0.05) and with hypercholesterolemia and liver disease in the UKBBC. In the DHS, PCSK7 missense variants were associated with circulating lipids. PCSK7 was expressed in hepatocytes and its hepatic expression correlated with that of lipogenic genes (P < 0.05). The rs236918 C allele was associated with upregulation of a new "intra-PCSK7" long noncoding RNA predicted to interact with the protein, higher hepatic and circulating PCSK7 protein (P < 0.01), which correlated with triglycerides (P = 0.04). In HepG2 cells, PCSK7 deletion reduced lipogenesis, fat accumulation, inflammation, transforming growth factor ß pathway activation, and fibrogenesis. In conclusion, PCSK7 gene variation is associated with dyslipidemia and more severe liver disease in high risk individuals, likely by modulating PCSK7 expression/activity.

Body mass index reduction improves the baseline procoagulant imbalance of obese subjects.

Obesity is a risk factor for cardiovascular diseases. The latter being dependent (at least in part) on plasma procoagulant imbalance (i.e., hypercoagulability). Information on hypercoagulability associated with obesity is scanty and mainly based on global traditional coagulation tests or on the measurement of individual components of coagulation (i.e., pro- and anticoagulants). Plasma from 33 obese subjects was investigated soon before endoscopic balloon placement and after removal (6 months later) by thrombin-generation procedures that are thought to represent much better than any other in vitro test the coagulation process occurring in vivo. We found that obese subjects possess a state of hypercoagulability as demonstrated by the modification of the main parameters of thrombin-generation. In particular, the median value (min-max) of the endogenous thrombin potential (ETP) of obese subjects at baseline was higher than that of controls [1968 (1335-2533) vs. 1710 (1010-2119), p < 0.001]. Endoscopic balloon placement achieved a BMI reduction from 38.9 (31.7-62.3) to 31.6 (21.9-53.3), p < 0.001 and a parallel reduction of thrombin-generation as demonstrated by the following findings. The ETP measured soon after balloon removal was significantly smaller than that measured at baseline [1783 (1224-2642) vs. 1968 (1335-2533), p < 0.01]. The other parameters of thrombin-generation, including lag-time, peak-thrombin, time-to-reach the peak and velocity index showed a pattern consistent with the ETP, both at baseline and soon after balloon removal. Endoscopic balloon placement achieves concomitant reduction of BMI and thrombin-generation in subjects with obesity.

Prevalence and Risk Factors of Significant Fibrosis in Patients With Nonalcoholic Fatty Liver Without Steatohepatitis.

BACKGROUND & AIMS: In patients with nonalcoholic fatty liver disease (NAFLD), nonalcoholic steatohepatitis (NASH) is a risk factor for the development of fibrosis. However, fibrosis has been observed in livers of patients without NASH. We aimed to estimate the prevalence of fibrosis in patients without NASH and risk factors for fibrosis. METHODS: We analyzed data from 1738 subjects (44.9% with severe obesity) in a cross-sectional liver biopsy cohort enrolled at referral centers in Italy and Finland. Biopsy specimens were analyzed histologically by a blinded pathologist at each center, and a diagnosis of NASH was made based on steatosis (≥5% of hepatocytes), hepatocellular ballooning, and lobular inflammation. We also collected data on demographic features, metabolic comorbidities, and genetic factors, and performed logistic regression analyses. Findings were validated using data from 118 consecutive patients with NAFLD who underwent sequential liver biopsies at tertiary referral centers in Italy. RESULTS: In the cross-sectional cohort, 132 of 389 patients (33.9%) with significant fibrosis had no NASH and 39 patients (10.0%) had no inflammation. The dissociation between NASH and fibrosis was significantly greater in patients with severe obesity (P < .005). Steatosis, ballooning, and lobular inflammation each were associated independently with significant fibrosis (P < .001); age, adiposity, fasting hyperglycemia, and the PNPLA3 I148M variant also were associated with fibrosis. In patients without, but not in those with NASH, significant fibrosis was associated with steatosis grade and the PNPLA3 I148M variant. In patients without NASH, age, fasting hyperglycemia, ballooning, and inflammation were associated with fibrosis. In the validation cohort, 16 of 47 patients (34.0%) with clinically significant fibrosis did not have NASH at baseline. In patients with fibrosis without baseline NASH, worsening of fibrosis (based on later biopsies) was associated with fasting hyperglycemia and more severe steatosis (P = .016). CONCLUSIONS: In an analysis of biopsy specimens collected from patients with NAFLD at a single time point, one third of patients with significant fibrosis did not have NASH. We validated this finding in a separate cohort. In patients without NASH, fasting hyperglycemia, severe steatosis, mild inflammation or ballooning, and the PNPLA3 I148M variant identified those at risk of significant fibrosis.

Protein phosphatase 1 regulatory subunit 3B gene variation protects against hepatic fat accumulation and fibrosis in individuals at high risk of nonalcoholic fatty liver disease.

Nonalcoholic fatty liver disease (NAFLD) is a major cause of liver damage and has a strong genetic component. The rs4841132 G>A variant, modulating the expression of protein phosphatase 1 regulatory subunit 3B (PPP1R3B), which is involved in glycogen synthesis, has been reported to reduce the risk of NAFLD but at the same time may favor liver disease by facilitating glycogen accumulation. The aim of this study was to assess the impact of rs4841132 on development of histologic steatosis and fibrosis in 1,388 European individuals in a liver biopsy cohort, on NAFLD hepatocellular carcinoma in a cross-sectional Italian cohort (n = 132 cases), and on liver disease at the population level in the United Kingdom Biobank cohort. We investigated the underlying mechanism by examining the impact of the variant on gene expression profiles. In the liver biopsy cohort, the rs4841132 minor A allele was associated with protection against steatosis (odds ratio [OR], 0.63; 95% confidence interval [CI], 0.42-0.95; P = 0.03) and clinically significant fibrosis (OR, 0.35; 95% CI, 0.14-0.87; P = 0.02) and with reduced circulating cholesterol (P = 0.02). This translated into protection against hepatocellular carcinoma development (OR, 0.22; 95% CI, 0.07-0.70; P = 0.01). At the population level, the rs4841132 variation was not associated with nonalcoholic or nonviral diseases of the liver but was associated with lower cholesterol (P = 1.7 × 10-8). In individuals with obesity, the A allele protecting against steatosis was associated with increased PPP1R3B messenger RNA expression and activation of lipid oxidation and with down-regulation of pathways related to lipid metabolism, inflammation, and cell cycle. Conclusion: The rs4841132 A allele is associated with protection against hepatic steatosis and fibrosis in individuals at high risk of NAFLD but not in the general population and against dyslipidemia. The mechanism may be related to modulation of PPP1R3B expression and hepatic lipid metabolism. (Hepatology Communications 2018;2:666-675).

Pulmonary aspiration in adjustable gastric banding carriers undergoing a second surgical procedure. Considerations on personal experience and review of the literature.

BACKGROUND: The observation of a relatively high number of pulmonary aspirations (PA) among gastric band (GB) carriers undergoing a second surgery, prompted us to modify our strategy for GB patients candidate to further operation under general anesthesia. MATERIAL OF STUDY AND RESULTS: In January 2013, following the occurrence of PA at the induction of general anesthesia in 1 GB carrier undergoing a further operation, we reviewed our Data Base between January 2005 and 2013, to explore the rate of pulmonary aspiration in patients GB carriers undergoing a second surgery. Considering the rate (3/172 - 1.7%) too high in comparison with non-GB carriers, we decided to deflate the banding before any further surgery planned under general anesthesia. We then retrospectively reviewed the occurrence of PA after having changed the protocol. Since February 2013, through December 2016, 81 GB carriers underwent a second surgery and not a single episode of PA occurred (0/81). DISCUSSION: The occurrence of PA in patients with GB seems greater than in non-GB patients. Larger series should be examined to assess the incidence of PA among this specific population. Awareness of the increased risk is important to general anesthesiologists and surgeons, considering the increasing number of GB carriers who may be in need of surgery. Our result after adopting the deflation policy, even though not statistically significant, seems highly suggestive. CONCLUSION: We believe that, considering the potentially severe consequences of PA, the gastric band should be deflated before any planned procedure requiring general anesthesia. Further data are needed. KEY WORDS: Adjustable gastric banding, Aspiration Pneumonia, Bariatric surgery, Morbid obesity, Pulmonary Aspiration.

Interferon lambda 4 rs368234815 TT>δG variant is associated with liver damage in patients with nonalcoholic fatty liver disease.

The interferon (IFN) lambda 3/4 (IFNL3/4) locus, influencing innate immunity regulation, has been associated with the severity of hepatitis and fibrosis progression during chronic hepatitis C infection, while contrasting results were reported in nonalcoholic fatty liver disease. In this study, we examined whether rs12979860 and the linked causal rs368234815 variant encoding for the alternative IFNL4 protein variant are associated with liver fibrosis and damage in a large multicenter cohort of patients at risk of nonalcoholic steatohepatitis. To clarify the mechanism, we also evaluated the impact on IFN-stimulated gene hepatic expression in a subset of patients. We considered 946 consecutive Italian individuals at risk of nonalcoholic steatohepatitis with liver histology evaluated according to Kleiner. The rs368234815 TT>δG, rs12979860 C>T, and patatin-like phospholipase-3 rs738409 C>G polymorphisms were genotyped; and IFN-stimulated gene hepatic expression (n = 16) was tested by TaqMan assays. We found that the rs368234815 TT allele was independently associated with severe F3-F4 fibrosis (odds ratio, 1.53; 95% confidence interval, 1.15-2.31; P = 0.005) and with severe (grade 2-3) lobular necroinflammation (odds ratio, 1.47; 95% confidence interval, 1.14-1.88; P = 0.002). The impact of rs368234815 on liver damage was generally more marked in nonobese individuals, where association with severe fibrosis, necroinflammation, and nonalcoholic steatohepatitis was observed (P < 0.05). IFN-stimulated genes were hypo-expressed in the liver of patients carrying the IFNL4 rs368234815 TT/TT genotype (P < 0.05). Similar results were observed when considering the rs12979860 polymorphism, which was in high linkage disequilibrium with rs368234815 (R2 = 0.87). CONCLUSION: The IFNL4 genotype is associated with severity of fibrosis in nonalcoholic fatty liver disease patients of European ancestry, likely by modulating the activation of innate immunity and necroinflammation. (Hepatology 2017;66:1885-1893).

Insulin resistance promotes Lysyl Oxidase Like 2 induction and fibrosis accumulation in non-alcoholic fatty liver disease.

In patients with non-alcoholic fatty liver disease (NAFLD), insulin resistance (IR) associates with fibrosis progression independently of the hepatic inflammation, but the mechanisms are still unclear. We modeled the independent contribution of inflammation (non-alcoholic steatohepatitis: NASH) by exploiting the methionine-choline deficient (MCD) diet, and that of IR by insulin receptor (InsR) haploinsufficiency (InsR+/-) in the pathogenesis of liver fibrosis in C57BL/6 mice. We confirmed the study findings in 96 patients with NAFLD. InsR+/- enhanced hepatic fat content and impaired hepatic insulin signaling leading to Forkhead box protein O1 (FoxO1) accumulation in MCD-fed mice. Remarkably, despite reduced inflammation and hampered transdifferentiation of hepatic stellate cells (HSCs), InsR+/- promoted hepatic fibrosis accumulation, which correlated with the induction of the Lysyl Oxidase Like 2 (Loxl2), involved in matrix stabilization. Loxl2 up-regulation was not a cell autonomous property of insulin resistant HSCs, but was dependent on microparticles (MPs) released specifically by insulin resistant hepatocytes (HEPs) exposed to fatty acids. The mechanism entailed FoxO1 up-regulation, as FoxO1 silencing normalized Loxl2 expression reversing fibrosis in InsR+/- MCD-fed mice. Loxl2 up-regulation was similarly detected during IR induced by obesity, but not by lipogenic stimuli (fructose feeding). Most importantly, LOXL2 up-regulation was observed in NAFLD patients with type 2 diabetes (T2D) and LOXL2 hepatic and circulating levels correlated with histological fibrosis progression. IR favors fibrosis deposition independently of the classic 'inflammation - HSC transdifferentiation' pathway. The mechanism entails a cross-talk between enhanced lipotoxicity in insulin resistant HEPs and Loxl2 production by HSCs, which was confirmed in patients with diabetes, thereby facilitating extracellular matrix (ECM) stabilization.

Liver fat accumulation is associated with circulating PCSK9.

BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) associates with cardiovascular disease independently of classic risk factors. Proprotein Convertase Subtilisin/Kexin type 9 (PCSK9) is secreted by hepatocytes and inhibits the uptake of low-density lipoproteins by targeting the receptor for degradation, and possibly lipogenesis. PCSK9 loss-of-function mutations and anti-PCKS9 drugs reduce LDL-cholesterol. AIM: To evaluate whether hepatic fat content is associated with circulating PCSK9. MATERIALS AND METHODS: In 201 consecutive patients biopsied for suspected nonalcoholic steatohepatitis, liver damage was quantified by NAFLD activity score, circulating PCSK9 by ELISA, and hepatic mRNA by qRT-PCR in a subset (n = 76). RESULTS: Circulating PCSK9 was associated with steatosis grade (p = 0.0011), necroinflammation (p < 0.001), ballooning (p = 0.005), and fibrosis stage (p = 0.001). At multivariate analysis, PCSK9 was associated with steatosis grade (p = 0.012), older age and lower BMI, independently of sex, hyperglycemia, and fibrosis/inflammation. Circulating PCSK9 was associated with hepatic expression of SREBP-1c (p = 0.0002) and FAS (p = 0.03). PCSK9 mRNA levels were also correlated with steatosis severity (p = 0.04) and hepatic APOB (p < 0.001), SREBP-1c (p = 0.047) and FAS expression (p = 0.001). CONCLUSIONS: Circulating PCSK9 increases with hepatic fat accumulation and correlates with the severity of steatosis, independently of metabolic confounders and liver damage. Modulation of PCSK9 synthesis and release might be involved in NAFLD pathogenesis. Key Messages Circulating PCSK9 levels increase with hepatic fat accumulation. Circulating PCSK9 levels are associated with increased de novo lipogenesis. Hepatic PCSK9 expression is associated with steatosis severity and activation of lipogenesis.

The rs2294918 E434K variant modulates patatin-like phospholipase domain-containing 3 expression and liver damage.

UNLABELLED: The patatin-like phosholipase domain-containing 3 (PNPLA3) rs738409 polymorphism (I148M) is a major determinant of hepatic fat and predisposes to the full spectrum of liver damage in nonalcoholic fatty liver disease (NAFLD). The aim of this study was to evaluate whether additional PNPLA3 coding variants contribute to NAFLD susceptibility, first in individuals with contrasting phenotypes (with early-onset NAFLD vs. very low aminotransferases) and then in a large validation cohort. Rare PNPLA3 variants were not detected by sequencing coding regions and intron-exon boundaries either in 142 patients with early-onset NAFLD nor in 100 healthy individuals with alanine aminotransferase <22/20 IU/mL. Besides rs738409 I148M, the rs2294918 G>A polymorphism (E434K sequence variant) was over-represented in NAFLD (adjusted P = 0.01). In 1,447 subjects with and without NAFLD, the 148M-434E (P < 0.0001), but not the 148M-434K, haplotype (P > 0.9), was associated with histological NAFLD and steatohepatitis. Both the I148M (P = 0.0002) and E434K variants (P = 0.044) were associated with serum ALT levels, by interacting with each other, in that the 434K hampered the association with liver damage of the 148M allele (P = 0.006). The E434K variant did not affect PNPLA3 enzymatic activity, but carriers of the rs2294918 A allele (434K) displayed lower hepatic PNPLA3 messenger RNA and protein levels (P < 0.05). CONCLUSIONS: Rare loss-of-function PNPLA3 variants were not detected in early-onset NAFLD. However, PNPLA3 rs2294918 E434K decreased PNPLA3 expression, lessening the effect of the I148M variant on the predisposition to steatosis and liver damage. This suggests that the PNPLA3 I148M variant has a codominant negative effect on triglycerides mobilization from lipid droplets, mediated by inhibition of other lipases.

Failure of gastric bypass following several gastrointestinal hemorrhages.

Gastrointestinal hemorrhage is an infrequent major complication of gastric bypass. We present a 22-year-old morbidly obese man who underwent a laparoscopic Roux-en-Y gastric bypass and had several life-threatening hemorrhages from both the gastric pouch and gastric remnant, associated with an intra-abdominal hemorrhage. The patient underwent two subsequent reoperations, leading eventually to gastrectomy. The possibility to discover all the sources of bleeding after gastric bypass is discussed, and the adoption of a modification of the procedure that allows the investigation of the excluded stomach is suggested.

Concurrent band and tube migration following acute pancreatitis.

A 52-year-old woman developed an acute pancreatitis 7 years after gastric banding for morbid obesity. The patient presented a stable weight loss. Three months before, a radiological band calibration showed a normal position of the band. Investigations revealed that the pancreatitis was related to the presence of gallstones, complicated by a stone in the choledocic tract. The band migrated completely into the gastric lumen and passed far down the jejunum. The band was still connected to the port but the connecting tube did not follow the normal course of duodenum, entering the stomach in the middle of the greater curvature and getting out on the same side 5 cm more distad. The patient underwent first an endoscopic retrograde cholangiopancreatogram with sphinterectomy, then a laparoscopy that allowed us to remove the band, via jejunotomy, and the tube, which was outside the stomach. The postoperative course was uneventful.