Michael A. Heneghan

Genome-wide association study identifies 12 new susceptibility loci for primary biliary cirrhosis.

In addition to the HLA locus, six genetic risk factors for primary biliary cirrhosis (PBC) have been identified in recent genome-wide association studies (GWAS). To identify additional loci, we carried out a GWAS using 1,840 cases from the UK PBC Consortium and 5,163 UK population controls as part of the Wellcome Trust Case Control Consortium 3 (WTCCC3). We followed up 28 loci in an additional UK cohort of 620 PBC cases and 2,514 population controls. We identified 12 new susceptibility loci (at a genome-wide significance level of P < 5 × 10−8) and replicated all previously associated loci. We identified three further new loci in a meta-analysis of data from our study and previously published GWAS results. New candidate genes include STAT4, DENND1B, CD80, IL7R, CXCR5, TNFRSF1A, CLEC16A and NFKB1. This study has considerably expanded our knowledge of the genetic architecture of PBC.

Repurposing diflunisal for familial amyloid polyneuropathy: A randomized clinical trial

IMPORTANCE Familial amyloid polyneuropathy, a lethal genetic disease caused by aggregation of variant transthyretin, induces progressive peripheral nerve deficits and disability. Diflunisal, a nonsteroidal anti-inflammatory agent, stabilizes transthyretin tetramers and prevents amyloid fibril formation in vitro. OBJECTIVE To determine the effect of diflunisal on polyneuropathy progression in patients with familial amyloid polyneuropathy. DESIGN, SETTING, AND PARTICIPANTS International randomized, double-blind, placebo-controlled study conducted among 130 patients with familial amyloid polyneuropathy exhibiting clinically detectable peripheral or autonomic neuropathy at amyloid centers in Sweden (Umeå), Italy (Pavia), Japan (Matsumoto and Kumamoto), England (London), and the United States (Boston, Massachusetts; New York, New York; and Rochester, Minnesota) from 2006 through 2012. INTERVENTION Participants were randomly assigned to receive diflunisal, 250 mg (n=64), or placebo (n=66) twice daily for 2 years. MAIN OUTCOMES AND MEASURES The primary end point, the difference in polyneuropathy progression between treatments, was measured by the Neuropathy Impairment Score plus 7 nerve tests (NIS+7) which ranges from 0 (no neurological deficits) to 270 points (no detectable peripheral nerve function). Secondary outcomes included a quality-of-life questionnaire (36-Item Short-Form Health Survey [SF-36]) and modified body mass index. Because of attrition, we used likelihood-based modeling and multiple imputation analysis of baseline to 2-year data. RESULTS By multiple imputation, the NIS+7 score increased by 25.0 (95% CI, 18.4-31.6) points in the placebo group and by 8.7 (95% CI, 3.3-14.1) points in the diflunisal group, a difference of 16.3 points (95% CI, 8.1-24.5 points; P < .001). Mean SF-36 physical scores decreased by 4.9 (95% CI, -7.6 to -2.2) points in the placebo group and increased by 1.5 (95% CI, -0.8 to 3.7) points in the diflunisal group (P < .001). Mean SF-36 mental scores declined by 1.1 (95% CI, -4.3 to 2.0) points in the placebo group while increasing by 3.7 (95% CI, 1.0-6.4) points in the diflunisal group (P = .02). By responder analysis, 29.7% of the diflunisal group and 9.4% of the placebo group exhibited neurological stability at 2 years (<2-point increase in NIS+7 score; P = .007). CONCLUSIONS AND RELEVANCE Among patients with familial amyloid polyneuropathy, the use of diflunisal compared with placebo for 2 years reduced the rate of progression of neurological impairment and preserved quality of life. Although longer-term follow-up studies are needed, these findings suggest benefit of this treatment for familial amyloid polyneuropathy. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00294671.

Twin studies in autoimmune disease: Genetics, gender and environment

Twin studies are powerful tools to discriminate whether a complex disease is due to genetic or environmental factors. High concordance rates among monozygotic (MZ) twins support genetic factors being predominantly involved, whilst low rates are suggestive of environmental factors. Twin studies have often been utilised in the study of systemic and organ specific autoimmune diseases. As an example, type I diabetes mellitus has been investigated to establish that that disease is largely affected by genetic factors, compared to rheumatoid arthritis or scleroderma, which have a weaker genetic association. However, large twin studies are scarce or virtually non-existent in other autoimmune diseases which have been limited to few sets of twins and individual case reports. In addition to the study of the genetic and environmental contributions to disease, it is likely that twin studies will also provide data in regards to the clinical course of disease, as well as risk for development in related individuals. More importantly, genome-wide association studies have thus far reported genomic variants that only account for a minority of autoimmunity cases, and cannot explain disease discordance in MZ twins. Future research is therefore encouraged not only in the analysis of twins with autoimmune disease, but also in regards to epigenetic factors or rare variants that may be discovered with next-generation sequencing. This review will examine the literature surrounding twin studies in autoimmune disease including discussions of genetics and gender.

Liver disease in pregnancy

Severe liver disease in pregnancy is rare. Pregnancy-related liver disease is the most frequent cause of liver dysfunction in pregnancy and provides a real threat to fetal and maternal survival. A rapid diagnosis differentiating between liver disease related and unrelated to pregnancy is required in women who present with liver dysfunction during pregnancy. Research has improved our understanding of the pathogenesis of pregnancy-related liver disease, which has translated into improved maternal and fetal outcomes. Here, we provide an overview of liver diseases that occur in pregnancy, an update on the key mechanisms involved in their pathogenesis, and assessment of available treatment options.

Dense fine-mapping study identifies new susceptibility loci for primary biliary cirrhosis

We genotyped 2,861 cases of primary biliary cirrhosis (PBC) from the UK PBC Consortium and 8,514 UK population controls across 196,524 variants within 186 known autoimmune risk loci. We identified 3 loci newly associated with PBC (at P < 5 × 10−8), increasing the number of known susceptibility loci to 25. The most associated variant at 19p12 is a low-frequency nonsynonymous SNP in TYK2, further implicating JAK-STAT and cytokine signaling in disease pathogenesis. An additional five loci contained nonsynonymous variants in high linkage disequilibrium (LD; r2 > 0.8) with the most associated variant at the locus. We found multiple independent common, low-frequency and rare variant association signals at five loci. Of the 26 independent non–human leukocyte antigen (HLA) signals tagged on the Immunochip, 15 have SNPs in B-lymphoblastoid open chromatin regions in high LD (r2 > 0.8) with the most associated variant. This study shows how data from dense fine-mapping arrays coupled with functional genomic data can be used to identify candidate causal variants for functional follow-up.

Sex and age are determinants of the clinical phenotype of primary biliary cirrhosis and response to ursodeoxycholic acid

UNLABELLED BACKGROUND, & AIMS: Studies of primary biliary cirrhosis (PBC) phenotypes largely have been performed using small and selected populations. Study size has precluded investigation of important disease subgroups, such as men and young patients. We used a national patient cohort to obtain a better picture of PBC phenotypes. METHODS We performed a cross-sectional study using the United Kingdom-PBC, patient cohort. Comprehensive data were collected for 2353 patients on diagnosis reports, response to therapy with ursodeoxycholic acid (UDCA), laboratory results, and symptom impact (assessed using the PBC-40 and other related measures). RESULTS Seventy-nine percent of the patients reported current UDCA, therapy, with 80% meeting Paris response criteria. Men were significantly less likely to have responded to UDCA than women (72% vs 80% response rate; P < .05); male sex was an independent predictor of nonresponse on multivariate analysis. Age at diagnosis was associated strongly and independently with response to UDCA; response rates ranged from 90% among patients who presented with PBC when they were older than age 70, to less than 50% for those younger than age 30 (P < .0001). Patients who presented at younger ages also were significantly more likely not to respond to UDCA therapy, based on alanine aminotransferase and aspartate aminotransferase response criteria, and more likely to report fatigue and pruritus. Women had mean fatigue scores 32% higher than mens (P < .0001). The increase in fatigue severity in women was related strongly (r = 0.58; P < .0001) to higher levels of autonomic symptoms (P < .0001). CONCLUSIONS Among patients with PBC, response to UDCA, treatment and symptoms are related to sex and age at presentation, with the lowest response rates and highest levels of symptoms in women presenting at younger than age 50. Increased severity of fatigue in women is related to increased autonomic symptoms, making dysautonomia a plausible therapeutic target.

British Society of Gastroenterology (BSG) guidelines for management of autoimmune hepatitis

Autoimmune hepatitis (AIH) is a chronic inflammatory liver disease which, if untreated, often leads to cirrhosis, liver failure and death. Major advances were made in its management based on controlled trials performed in England and the USA in the 1970s and 1980s. Unfortunately, in recent decades there has been a dearth of controlled clinical trials and, thus, many questions regarding the optimal management of this disease remain unanswered. Many promising newer immunosuppressive therapies await formal comparison with standard therapies and also many important details in relation to the application of standard therapies remain unclear. These guidelines describe the optimal management strategies in adults based on available published evidence, including the American Association for the Study of Liver Diseases practice guidelines for the diagnosis and treatment of AIH published in 2002 and recently updated.

Pregnancy outcome after liver transplantation: A single‐center experience of 71 pregnancies in 45 recipients

Infertility is common in women with end‐stage liver disease. Successful liver transplant (LT), however, can restore childbearing potential. Controversy exists regarding the most appropriate immunosuppressive regimen and timing of conception following LT. We report the outcomes of a review of all pregnancies occurring following LT at Kings College Hospital, London, from 1988 to 2004. Seventy‐one pregnancies were recorded in 45 women. Tacrolimus (60%) and cyclosporin A (38%) were the predominant primary immunosuppressive agents used. Median age at conception was 29 years (range, 19–42), with a median time from LT to conception of 40 months (range, 1–111). There were 50 live births, and no maternal or fetal deaths related to pregnancy. There were no graft losses. Median gestation was 37 weeks (range, 24–42) with a median birth weight of 2,690 g (range, 554–4,260). Caesarean section was performed in 40% of pregnancies. Complications included pregnancy‐induced hypertension in 20%, preeclampsia in 13%, acute cellular rejection in 17%, and renal impairment in 11%. There was no statistically significant difference in complication rates observed between immunosuppressive groups. Pregnancies occurring within 1‐year posttransplant had an increased incidence of prematurity, low birth weight, and acute cellular rejection compared to those occurring later than 1 year. In conclusion, this study confirms that favorable outcomes of pregnancy post‐LT can be expected for the majority of patients. However, delaying pregnancy until after 1‐year post‐LT is advisable, since doing so maybe associated with a lower risk of prematurity. Liver Transpl 12:1138–1143, 2006.

Evaluation of risk factors in the development of hepatocellular carcinoma in autoimmune hepatitis: Implications for follow-up and screening.

Hepatocellular carcinoma (HCC) has traditionally been considered a rare complication of cirrhosis secondary to autoimmune hepatitis (AIH), yet the true incidence remains unknown due to a lack of published data. Consequently, some professional guidelines do not mandate routine surveillance for HCC in this condition. Our aims were to evaluate the rate at which HCC develops among a large, prospectively obtained cohort of patients with AIH at a single center. Demographic, clinical, and laboratory indices associated with the development of HCC were also identified. HCC was discovered in 15 of 243 patients with AIH, all of whom had type 1 AIH equating to 1090 cases per 100,000 patient follow‐up years. HCC occurred in the same proportion of females as males, 6.1% versus 6.4%, P = 0.95. HCC occurred more frequently in patients who had cirrhosis at presentation, 9.3% versus 3.4%, P = 0.048, or who had a variceal bleed as the index presentation of AIH, 20% versus 5.3%, P = 0.003. The median duration from time of confirmed cirrhosis to a diagnosis of HCC was 102.5 months, range 12‐195 months. Median survival in patients whose HCC was diagnosed on surveillance was 19 months (range 6‐36 months) compared with 2 months (range 0‐14 months) for patients presenting symptomatically (P = 0.042). Conclusion: Cirrhosis in AIH is the sine qua non for HCC development, which subsequently occurs at a rate of 1.1% per year and affects men and women in equal proportions. (HEPATOLOGY 2008.)

The impact of diabetes mellitus on fibrosis progression in patients transplanted for hepatitis C.

Despite the recognition of numerous factors for aggressive hepatitis C virus (HCV) recurrence after liver transplantation (LT) our understanding of this phenomenon is incomplete. We tested the hypothesis that diabetes mellitus (DM) was implicated. One hundred sixty‐three patients undergoing primary LT for HCV from 1990 to 2004 were evaluated and biopsies were scored according to the modified Ishak score. Severe recurrence of HCV was defined as a fibrosis score ≥4 within 6 years of LT. Risk factors assessed included recipient, donor and transplant variables. Fifty‐four patients (33.1%) had a fibrosis score ≥4 at the end of the study period. Factors associated with progression to severe fibrosis was donor age (p = 0.008) especially donor age >55 (p = 0.038, HR 2.43), pre‐LT DM (p = 0.039, HR 2.68) and DM post‐LT (p = 0.004, HR 3.28). The combination of receiving a liver from a donor older than 55 years and having DM post‐LT was associated with an 8.38‐fold risk of progression to severe fibrosis (p = 0.000124) when compared to patients not diabetic post‐LT who received livers from donors aged <55 years. These data indicate that diabetic status is one of the more important variables determining the severity of HCV recurrence and is synergistic with donor age. This observation may provide an additional management opportunity to modify the impact of HCV recurrence.