Search

Background & Aims Autoimmune hepatitis (AIH) is an uncommon autoimmune liver disease of unknown etiology. We used a genome-wide approach to identify genetic variants that predispose individuals to AIH. Methods We performed a genome-wide association study of 649 adults in The Netherlands with AIH type 1 and 13,436 controls. Initial associations were further analyzed in an independent replication panel comprising 451 patients with AIH type 1 in Germany and 4103 controls. We also performed an association analysis in the discovery cohort using imputed genotypes of the major histocompatibility complex region. Results We associated AIH with a variant in the major histocompatibility complex region at rs2187668 (P = 1.5 x 10-78). Analysis of this variant in the discovery cohort identified HLA-DRB1*0301 (P = 5.3 x 10-49) as a primary susceptibility genotype and HLA-DRB1*0401 (P = 2.8 x 10-18) as a secondary susceptibility genotype. We also associated AIH with variants of SH2B3 (rs3184504, 12q24; P = 7.7 x 10-8) and CARD10 (rs6000782, 22q13.1; P = 3.0 x 10-6). In addition, strong inflation of association signal was found with single-nucleotide polymorphisms associated with other immune-mediated diseases, including primary sclerosing cholangitis and primary biliary cirrhosis, but not with single-nucleotide polymorphisms associated with other genetic traits. Conclusions In a genome-wide association study, we associated AIH type 1 with variants in the major histocompatibility complex region, and identified variants of SH2B3and CARD10 as likely risk factors. These findings support a complex genetic basis for AIH pathogenesis and indicate that part of the genetic susceptibility overlaps with that for other immune-mediated liver diseases. [ABSTRACT FROM AUTHOR]

Small studies have found that black patients with autoimmune hepatitis (AIH) present with more aggressive disease. We aimed to characterize the presentation and outcome in black and white patients with AIH. We performed a retrospective study, collecting information from databases of patients with AIH attending the Institute of Liver studies at King's College Hospital, London (1971–October 2015, the Royal Free Hospital, London (1982 through December 2016) and the multicenter Dutch Autoimmune Hepatitis Study Group cohort (2006–August 2016). We identified 88 black patients with AIH and we compared their clinical characteristics and outcomes to 897 white patients with AIH. Black patients presented at a younger age (median 38 years vs 45 years) (P =.007), had higher IgG levels (mean 31.0 mg/dL vs 27.5 mg/dL) (P =.04), but there were no significant differences between groups in auto-antibody profiles, International AIH Group scores, or sex distribution of disease. A higher proportion of black patients had systemic lupus erythematosus (10%) than white patients (2%) (P ≤.001). There was no significant difference in proportions of patients with a response to standard therapy (86% for black patients vs 91% for white patients; P =.20) or in rate of relapse (57% vs 50%; P =.3). Despite this, black patients had an increased risk of liver transplantation and liver-related death (hazard ratio 2.4, 95% confidence interval, 1.4–4.0; P <.001). Overall mortality was similar between the two groups. In a comparison of black and white patients with AIH in Europe, we found that black patients present at a younger age, have higher levels of IgG levels, and a greater proportion have SLE. We also found black patients to have a greater risk of liver transplantation and liver-related mortality, indicating more aggressive disease. [ABSTRACT FROM AUTHOR]

Background & Aims There have been few reproducible studies of mortality in patients with autoimmune hepatitis (AIH) and its variants. We calculated mortality in a large national cohort of patients with AIH, with vs without cirrhosis, in the Netherlands. Methods We collected data from 449 patients with established AIH (77% female), from 6 academic and 10 non-academic hospitals in the Netherlands. We identified 29 patients with AIH and primary biliary cholangitis and 35 patients with AIH and primary sclerosing cholangitis (AIH-PSC). Mortality and liver transplantation data were assessed from August 1, 2006 through July 31, 2016. Standardized mortality ratios (SMR) were calculated using age-, sex-, and calendar year-matched mortality for the general Dutch population. Results During the 10-year follow-up period, 60 patients (13%) died (mean age, 71 years; range, 33–94 years). Twenty-six causes of death were liver related (43%), whereas the others could not be attributed to liver disease. Patients with AIH and cirrhosis had significantly higher mortality than the general population (SMR, 1.9; 95% CI, 1.2–3.4), whereas patients without cirrhosis did not (SMR, 1.2; 95% CI, 0.8–1.8). Patients with AIH-PSC had the largest increase in mortality, compared to the general population (SMR, 4.7; 95% CI, 1.5–14.6), of all groups analyzed. Mortality in patients with AIH and primary biliary cholangitis was not greater than the general population. Four or more relapses per decade or not achieving remission was associated with an increase in liver-related death or liver transplantation. Nine patients underwent liver transplantation; 2 died from non-liver related causes. Four of 9 patients on the waitlist for transplantation died before receiving a donated liver. Conclusion In an analysis of data from a large national cohort of patients with AIH, we found increased mortality of patients with cirrhosis, but not of patients without cirrhosis, compared to the general Dutch population. Survival was significantly reduced in patients with AIH and features of concurrent PSC. [ABSTRACT FROM AUTHOR]

Background & Aims Hepatitis C virus (HCV) co-opts the very-low-density lipoprotein pathway for morphogenesis, maturation, and secretion, and circulates as lipoviroparticles (LVPs). We investigated the functions and underlying mechanisms of the lipid-associated TM6SF2 protein in modulating LVP formation and the HCV life cycle. Methods We knocked down or overexpressed TM6SF2 in hepatic cells and examined HCV infection, measuring viral RNA and protein levels and infectious LVP titers. The density of secreted LVPs was evaluated by iodixanol gradient assay. We measured levels and patterns of TM6SF2 in liver biopsies from 73 patients with chronic hepatitis C, livers of HCV-infected humanized Alb-uPA/SCID/beige mice, and HCV-infected Huh7.5.1 cells. Results TM6SF2 knockdown in hepatocytes reduced viral RNA and infectious viral particle secretion without affecting HCV genome replication, translation, or assembly. Overexpression of TM6SF2 reduced intracellular levels of HCV RNA and infectious LVPs, and conversely increased their levels in the culture supernatants. In HCV-infected cells, TM6SF2 overexpression resulted in production of more infectious LVPs in the lower-density fractions of supernatant. HCV infection increased TM6SF2 expression in cultured cells, humanized livers of mice, and liver tissues of HCV patients. TM6SF2 messenger RNA levels correlated positively with HCV RNA levels in liver biopsies from patients. SREBF2 appears to mediate the ability of HCV to increase the expression of TM6SF2 in hepatic cells. Conclusions In studies of cells, mice and human liver tissues, we found TM6SF2 is required for maturation, lipidation, and secretion of infectious LVPs. HCV, in turn, up-regulates expression of TM6SF2 to facilitate productive infection. Graphical abstract [ABSTRACT FROM AUTHOR]

Background & Aims Drug-induced liver injury (DILI) has features similar to those of other liver diseases including autoimmune hepatitis (AIH). We aimed to characterize the clinical and autoimmune features of liver injury caused by nitrofurantoin, minocycline, methyldopa, or hydralazine. Methods We analyzed data from 88 cases of DILI attributed to nitrofurantoin, minocycline, methyldopa, or hydralazine included in the Drug-Induced Liver Injury Network prospective study from 2004 through 2014. Sera were collected from patients at baseline and follow-up examination and tested for levels of immunoglobulin G (IgG), antibodies to nuclear antigen (ANA), smooth muscle (SMA), and soluble liver antigen (SLA). An autoimmune score was derived on the basis of increases in levels of IgG, ANA, SMA, and SLA (assigned values of 0, 1+, or 2+). AIH-associated HLA-DRB1*03:01 and HLA-DRB1*04:01 allele frequencies were compared with those of the general population (controls). Results Of the 88 cases, 80 were women (91%), 74% had hepatocellular injury, and 25% had severe injury. At the onset of DILI, 39% of cases had increased levels of IgG, 72% had increased levels of ANA, 60% had increased levels of SMA, and none had increases in SLA. A phenotype of autoimmunity (autoimmune score ≥2) was observed in 82% of cases attributed to nitrofurantoin and 73% of cases attributed to minocycline (73%) but only 55% of cases attributed to methyldopa and 43% of cases attributed to hydralazine ( P = .16 for nitrofurantoin and minocycline vs methyldopa and hydralazine). We observed a decrease in numbers of serum samples positive for ANA ( P = .01) or SMA ( P < .001) and in autoimmune scores ( P < .001) between DILI onset and follow-up. Similar percentages of patients with DILI had HLA-DRB1*03:01 (15%) and HLA-DRB1*04:01 (9%) as controls (12% and 9%, respectively). Conclusions In analysis of data from the DILIN prospective study, we found that most cases of DILI attributed to nitrofurantoin or minocycline and about half of cases that were due to methyldopa and hydralazine have a phenotype of autoimmunity similar to AIH. These features decrease with recovery of the injury and are not associated with the typical HLA alleles found in patients with idiopathic AIH. [ABSTRACT FROM AUTHOR]