International genome-wide meta-analysis identifies new primary biliary cirrhosis risk loci and targetable pathogenic pathways.

Primary biliary cirrhosis (PBC) is a classical autoimmune liver disease for which effective immunomodulatory therapy is lacking. Here we perform meta-analyses of discovery data sets from genome-wide association studies of European subjects (n=2,764 cases and 10,475 controls) followed by validation genotyping in an independent cohort (n=3,716 cases and 4,261 controls). We discover and validate six previously unknown risk loci for PBC (Pcombined<5 × 10(-8)) and used pathway analysis to identify JAK-STAT/IL12/IL27 signalling and cytokine-cytokine pathways, for which relevant therapies exist

Genome-wide association study of primary sclerosing cholangitis identifies new risk loci and quantifies the genetic relationship with inflammatory bowel disease.

Primary sclerosing cholangitis (PSC) is a rare progressive disorder leading to bile duct destruction; ∼75% of patients have comorbid inflammatory bowel disease (IBD). We undertook the largest genome-wide association study of PSC (4,796 cases and 19,955 population controls) and identified four new genome-wide significant loci. The most associated SNP at one locus affects splicing and expression of UBASH3A, with the protective allele (C) predicted to cause nonstop-mediated mRNA decay and lower expression of UBASH3A. Further analyses based on common variants suggested that the genome-wide genetic correlation (rG) between PSC and ulcerative colitis (UC) (rG = 0.29) was significantly greater than that between PSC and Crohn's disease (CD) (rG = 0.04) (P = 2.55 × 10-15). UC and CD were genetically more similar to each other (rG = 0.56) than either was to PSC (P < 1.0 × 10-15). Our study represents a substantial advance in understanding of the genetics of PSC

Carriage of a tumor necrosis factor polymorphism amplifies the cytotoxic T-lymphocyte antigen 4 attributed risk of primary biliary cirrhosis:evidence for a gene-gene interaction

Common genetic variants significantly influence complex diseases such as primary biliary cirrhosis (PBC). We recently reported an association between PBC and a single nucleotide polymorphism (rs231725) of the immunoreceptor gene cytotoxic T-lymphocyte antigen 4 (CTLA4). We hypothesized that PBC risk attributed to this polymorphism might be increased by propensity to an overly robust inflammatory response. Thus, we examined its potential interaction with the commonly studied −308AG promoter polymorphism (rs1800629) of the tumor necrosis factor (TNF) gene for which the variant TNF2A allele causes increased TNF production. The polymorphisms were genotyped in 866 PBC patients and 761 controls from independent US and Canadian registries; the effects of individual single nucleotide polymorphisms (SNPs) and their interaction on PBC risk was assessed by logistic regression. The reported association of PBC with the CTLA4 “A/A” genotype was replicated in the Canadian cohort and significant for PBC risk in the combined data (odds ratio [OR], 1.68; P = 0.0005). TNF2A allele frequency was elevated in PBC patients, but only reached borderline significance using the combined data (OR, 1.21; P = 0.042). Analysis showed that TNF2A carriage was significantly increased in CTLA4 “A/A” PBC patients compared with CTLA4 “A/A” controls (39.7% versus 16.5%, P = 0.0004); no apparent increase of TNF2A carriage was noted in CTLA4 “A/G” or “G/G” individuals. Finally, interaction under a logistic model was highly significant, as TNF2A carriage in combination with the CTLA4 “A/A” genotype was present in 6.5% of PBC patients, compared with 1.7% of controls (OR, 3.98; P < 0.0001). CONCLUSION: TNF2A amplifies the CTLA4 rs231725 “A/A” genotype risk for PBC. Although the mechanisms remain unclear, the premise that deficiency in T-cell regulation resulting in an increased risk of PBC is amplified by overexpression of an important proinflammatory cytokine provides a basis for future functional studies

Bile Acid Profiles in Primary Sclerosing Cholangitis and their Ability to Predict Hepatic Decompensation

Background and Aims: Altered bile acid (BA) homeostasis is an intrinsic facet of cholestatic liver diseases, but clinical usefulness of plasma BA assessment in primary sclerosing cholangitis (PSC) remains understudied. We performed BA profiling in a large retrospective cohort of patients with PSC and matched healthy controls, hypothesizing that plasma BA profiles vary among patients and have clinical utility. Approach and Results: Plasma BA profiling was performed in the Clinical Biochemical Genetics Laboratory at Mayo Clinic using a mass spectrometry based assay. Cox proportional hazard (univariate) and gradient boosting machines (multivariable) models were used to evaluate whether BA variables predict 5-year risk of hepatic decompensation (HD; defined as ascites, variceal hemorrhage, or encephalopathy). There were 400 patients with PSC and 302 controls in the derivation cohort (Mayo Clinic) and 108 patients with PSC in the validation cohort (Norwegian PSC Research Center). Patients with PSC had increased BA levels, conjugated fraction, and primary-to-secondary BA ratios relative to controls. Ursodeoxycholic acid (UDCA) increased total plasma BA level while lowering cholic acid and chenodeoxycholic acid concentrations. Patients without inflammatory bowel disease (IBD) had primary-to-secondary BA ratios between those of controls and patients with ulcerative colitis. HD risk was associated with increased concentration and conjugated fraction of many BA, whereas higher G:T conjugation ratios were protective. The machine-learning model, PSC-BA profile score (concordance statistic [C-statistic], 0.95), predicted HD better than individual measures, including alkaline phosphatase, and performed well in validation (C-statistic, 0.86). Conclusions: Patients with PSC demonstrated alterations of plasma BA consistent with known mechanisms of cholestasis, UDCA treatment, and IBD. Notably, BA profiles predicted future HD, establishing the clinical potential of BA profiling, which may be suited for use in clinical trials

Human Wagering Behavior Depends on Opponents' Faces

Research in competitive games has exclusively focused on how opponent models are developed through previous outcomes and how peoples' decisions relate to normative predictions. Little is known about how rapid impressions of opponents operate and influence behavior in competitive economic situations, although such subjective impressions have been shown to influence cooperative decision-making. This study investigates whether an opponent's face influences players' wagering decisions in a zero-sum game with hidden information. Participants made risky choices in a simplified poker task while being presented opponents whose faces differentially correlated with subjective impressions of trust. Surprisingly, we find that threatening face information has little influence on wagering behavior, but faces relaying positive emotional characteristics impact peoples' decisions. Thus, people took significantly longer and made more mistakes against emotionally positive opponents. Differences in reaction times and percent correct were greatest around the optimal decision boundary, indicating that face information is predominantly used when making decisions during medium-value gambles. Mistakes against emotionally positive opponents resulted from increased folding rates, suggesting that participants may have believed that these opponents were betting with hands of greater value than other opponents. According to these results, the best “poker face” for bluffing may not be a neutral face, but rather a face that contains emotional correlates of trustworthiness. Moreover, it suggests that rapid impressions of an opponent play an important role in competitive games, especially when people have little or no experience with an opponent.Japan. Science and Technology Agency (Exploratory Research for Advanced Technology (ERATO) grant)National Eye Institute (R01 EY01362