Novel insights into autoimmune liver diseases provided by genome-wide association studies

Autoimmune hepatitis (AIH), primary biliary cirrhosis (PBC) and primary sclerosing cholangitis (PSC) are complex disorders, resulting from the interaction of genetic and environmental factors. For many years, investigators have attempted to delineate the genetic architecture of these conditions, aiming to elucidate disease pathogenesis and identify molecular targets for pharmacotherapy. Early genetic studies consisted of HLA association studies and non-HLA candidate gene association studies, designed to identify association with selected HLA or non-HLA loci. HLA association studies identified HLA risk loci that are now well-established. Non-HLA candidate gene studies were less fruitful because they were mostly underpowered to detect modest effects and were frequently designed to investigate one or two functional polymorphisms, meaning that gene coverage was poor. Furthermore, weak associations detected in one small cohort were often never validated. If replication studies were undertaken, the results were often conflicting. More recently, a series of genome-wide association studies (GWAS) and related study designs have evaluated the impact of common genetic variants (frequency >5% in the general population) across the entire genome. These studies have identified several non-HLA risk loci for autoimmune liver disease. The majority of risk loci detected are similar to those of non-hepatic immune-mediated diseases, suggesting that outcomes from GWAS and related genetic studies reflect broad phenotypic themes rather than traditional clinical conditions. The specific genetic basis of these PBC and PSC associated inflammatory themes as determined by GWAS is described and discussed in the context of interacting genetic and non-genetic (including environmental) factors.     

鲍曼不动杆菌异质性耐药研究进展

异质性耐药是指细菌的不同亚群对某种抗菌药物表现出不同的敏感性,多报道于对万古霉素中介的金黄色葡萄球菌。近年来,在以鲍曼不动杆菌、肺炎克雷伯菌和铜绿假单胞菌等为代表的革兰阴性菌中这一现象不断地被揭示,并且被逐渐认识到其可能是导致抗感染治疗失败的原因之一。细菌一旦出现异质性耐药,在抗菌药物选择性压力下,即使是小部分的耐药亚群也可表现出高水平的表型耐药,从而导致临床应用抗菌药物抗感染治疗的失败。异质性耐药体现了细菌群体从部分耐药向完全耐药转变的过程。研究异质性耐药对于认识临床常见病原菌耐药的发展过程,以及评估治疗方案和指导临床使用抗菌药物具有重要的意义。本文对鲍曼不动杆菌异质性耐药的研究现状进行了综述。     

Statistical challenges for genome-wide association studies of suicidality using family data

The etiology of suicide is complex in nature with both environmental and genetic causes that are extremely diverse. This extensive heterogeneity weakens the relationship between genotype and phenotype and as a result, we face many challenges when studying the genetic etiology of suicide. We are now in the midst of a genetics revolution, where genotyping costs are decreasing and genotyping speed is increasing at a fast rate, allowing genetic association studies to genotype thousands to millions of SNPs that cover the entire human genome. As such, genome-wide association studies (GWAS) are now the norm. In this article we address several statistical challenges that occur when studying the genetic etiology of suicidality in the age of the genetics revolution. These challenges include: (1) the large number of statistical tests; (2) complex phenotypes that are difficult to quantify; and (3) modest genetic effect sizes. We address these statistical issues in the context of family-based study designs. Specifically, we discuss several statistical extensions of family-based association tests (FBATs) that work to alleviate these challenges. As our intention is to describe how statistical methodology may work to identify disease variants for suicidality, we avoid the mathematical details of the methodologies presented.     

Cellular basis of diabetic nephropathy: V. Endoglin expression levels and diabetic nephropathy risk in patients with Type 1 diabetes

Endoglin is an accessory receptor molecule that, in association with transforming growth factor β (TGF-β) family receptors Types I and II, binds TGF-β1, TGF-β3, activin A, bone morphogenetic protein (BMP)-2 and BMP-7, regulating TGF-β dependent cellular responses. Relevant to diabetic nephropathy, endoglin, expressed in vascular endothelial and smooth muscle cells, fibroblasts, and mesangial cells, negatively regulates extracellular matrix (ECM). The aim of this study was to evaluate endoglin expression in cultured skin fibroblasts from patients with Type 1 diabetes with and without diabetic nephropathy. Kidney and skin biopsies were performed in 125 Type 1 diabetic patients. The 20 with the fastest rate of mesangial expansion (estimated by electron microscopy) and proteinuria (“fast-track”) and the 20 with the slowest rate and normoalbuminuria (“slow-track”), along with 20 controls were studied. Endoglin mRNA expression was assessed by microarray and quantitative real-time polymerase chain reaction (QRT-PCR) and protein expression by Western blot. Age and sex distribution were similar among groups. Diabetes duration was similar (20±8 vs. 24±7 years), hemoglobin A1c lower (8.4±1.2% vs. 9.4±1.5%), and glomerular filtration rate higher (115±13 vs. 72±20 ml/min per 1.73 m²) in slow-track vs. fast-track patients. Microarray endoglin mRNA expression levels were higher in slow-track (1516.0±349.9) than fast-track (1211.0±274.9; P=.008) patients or controls (1223.1±422.9; P=.018). This was confirmed by QRT-PCR. Endoglin protein expression levels correlated with microarray (r=0.59; P=.044) and QRT-PCR (r=0.61; P=.034) endoglin mRNA expression. These studies are compatible with the hypothesis that slow-track Type 1 diabetic patients, strongly protected from diabetic nephropathy, have distinct cellular behaviors that may be associated with reduced ECM production.     

Efficacy and safety of HER2-targeted therapy in patients with colorectal cancer: What should we expect from a meta-analysis?

Background and objectiveHuman epidermal growth factor receptor 2 (HER2) is an effective therapeutic target for breast and stomach cancers. However, the application of HER2-targeted therapy in colorectal cancer (CRC) remains controversial. We sought to assess the efficacy and safety of HER2-targeted therapy in CRC by performing a meta-analysis of relevant studies.MethodsWe searched PubMed, Embase, Cochrane Library, Web of Science, and the ClinicalTrials.gov database to retrieve relevant studies. STATA 16 was used for the statistical analysis. The objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS), and incidence of treatment?related adverse events (TRAEs) were used as the outcome indicators analyzed by random- or fixed-effects models.ResultsA total of 267 patients from nine studies were included in this meta-analysis. The overall ORR and DCR were 27.5% (95% CI 16.8% to 39.6%) and 68.9% (95% CI 55.4% to 81.0%), respectively. No significant heterogeneity was found in PFS among these studies and the overall median PFS was 4.35 months (95% CI 3.70 to 4.99). The overall incidence of all-grade and grade 3 or higher adverse events were 93.5% (95% CI 88.4% to 97.4%) and 16.8% (95% CI 4.8% to 33.3%).ConclusionsHER2-targeted therapy was confirmed as a promising treatment for colorectal cancer, warranting further high-quality clinical randomized controlled trials to verify.