Piotr Milkiewicz

Variants at IRF5-TNPO3, 17q12-21 and MMEL1 are associated with primary biliary cirrhosis

We genotyped individuals with primary biliary cirrhosis and unaffected controls for suggestive risk loci (genome-wide association P < 1 × 10−4) identified in a previous genome-wide association study. Combined analysis of the genome-wide association and replication datasets identified IRF5-TNPO3 (combined P = 8.66 × 10−13), 17q12-21 (combined P = 3.50 × 10−13) and MMEL1 (combined P = 3.15 × 10−8) as new primary biliary cirrhosis susceptibility loci. Fine-mapping studies showed that a single variant accounts for the IRF5-TNPO3 association. As these loci are implicated in other autoimmune conditions, these findings confirm genetic overlap among such diseases.

Recurrence of autoimmune hepatitis after liver transplantation.

BACKGROUND The literature data on the recurrence of autoimmune hepatitis (AIH) after orthotopic liver transplantation (OLTX) is scanty. METHODS We analyzed the frequency of recurrent AIH in 47 patients who had been transplanted for AIH and survived at least 1 year after surgery. The following criteria were applied to diagnose recurrence: (1) positive autoantibodies in the titer> or =1:40; (2) hypertransaminasemia; (3) histological features of chronic hepatitis; (4) need of reintroduction or significant increase of steroids; and (5) lack of serum markers of viral hepatitis. RESULTS A total of 13 patients (1 male/12 females) developed recurrent AIH after an interval of 6-63 months after OLTX (mean 29 months). Mean AST level at recurrence was 542+/-129 U/L. Three patients from this group needed regrafting. Mismatch of DR3+ recipient and DR3- donor was not more common in the recurrent disease group (37%) compared to the nonrecurrence group (31%) (P=NS). CONCLUSIONS Recurrence of AIH after OLTX was diagnosed in a high proportion of patients and some of them required regrafting. DR3+ patients are not particularly prone to develop recurrence.

Biliary Tract Complications after Liver Transplantation: A Review

Biliary complications continue to be a major cause of morbidity in liver transplant recipients with an incidence of 10–30% following whole-organ transplantation and a mortality rate of up to 10%. Biliary leaks and strictures are most common but sphincter of Oddi dysfunction, hemobilia, and biliary obstruction are also observed. Biliary complications may be related to various factors such as hepatic artery patency, preservation injury, cytomegalovirus infection, chronic ductopenic rejection, ABO incompatibility, and technical reasons. The latter include imperfect anastomosis, T-tube-related complications and the use of partial liver grafts when cut surface biliary leaks or inadvertent bile duct injuries may occur during parenchymal division. The usage of a T-tube for duct-to-duct anastomosis in whole-organ liver transplantation remains controversial, mainly because of the high rates of T-tube-related complications observed in many series. In this article we review the etiology, as well as the main types of biliary complications according to the technique of biliary reconstruction and liver transplant procedure performed. Their management is also discussed with interventional radiology and endoscopic techniques emerging as the preferred treatment option, obviating the need for surgery in a selected majority of patients.

PBC Screen: An IgG/IgA dual isotype ELISA detecting multiple mitochondrial and nuclear autoantibodies specific for primary biliary cirrhosis

A dual isotype (IgG, IgA) enzyme-linked immunosorbent assay (ELISA) designed to provide enhanced detection of primary biliary cirrhosis (PBC)-specific autoantibodies against both major mitochondrial and nuclear antigens has been developed and recently become commercially available. The assay (PBC Screen) simultaneously detects IgG and IgA autoantibodies to the immunodominant portions of the 3 major mitochondrial (MIT3) and nuclear (gp210, and sp100) antigens. The aim of this study was to compare the performance of the PBC Screen to the combined performance obtained with individual IgG ELISAs to MIT3, gp210, and sp100 on a large group of selected patients from multiple centers. A total of 1175 patients with PBC and 1232 subjects without PBC were evaluated. Non-PBC groups included healthy controls (624) as well as individuals with autoimmune hepatitis (281), primary sclerosing cholangitis (77), viral hepatitis (91 hepatitis B and 98 hepatitis C), other liver diseases (31), and other infectious or autoimmune diseases (30). The PBC Screen at the receiver operator characteristic optimized cutoff of 27.8 units, had an overall sensitivity of 83.8%, specificity of 94.7% and area under curve of 0.9212. This was similar to the specificity of 96.1% obtained by the combined results of individual MIT3, sp100, and gp210 IgG ELISAs (kappa index at 0.898). Of the 253 PBC patients without AMA detectable by immunofluorescence, 113 (44.7%) were interpreted as positive for PBC-specific autoantibodies. In conclusion, the PBC Screen is an appropriate first-line test for the diagnosis of PBC, including for patients negative for markers assessed using conventional methods.

Transplantation for cystic fibrosis: Outcome following early liver transplantation

Background and Aim Life expectancy in patients with cystic fibrosis (CF) has recently improved due to numerous factors, including a multidisciplinary approach to their management. Prolonged survival may have led to an increasing impact of liver disease on the prognosis of CF patients. The aim of this study was to assess the role of liver transplantation in patients with CF.

Immunochip analyses identify a novel risk locus for primary biliary cirrhosis at 13q14, multiple independent associations at four established risk loci and epistasis between 1p31 and 7q32 risk variants

To further characterize the genetic basis of primary biliary cirrhosis (PBC), we genotyped 2426 PBC patients and 5731 unaffected controls from three independent cohorts using a single nucleotide polymorphism (SNP) array (Immunochip) enriched for autoimmune disease risk loci. Meta-analysis of the genotype data sets identified a novel disease-associated locus near the TNFSF11 gene at 13q14, provided evidence for association at six additional immune-related loci not previously implicated in PBC and confirmed associations at 19 of 22 established risk loci. Results of conditional analyses also provided evidence for multiple independent association signals at four risk loci, with haplotype analyses suggesting independent SNP effects at the 2q32 and 16p13 loci, but complex haplotype driven effects at the 3q25 and 6p21 loci. By imputing classical HLA alleles from this data set, four class II alleles independently contributing to the association signal from this region were identified. Imputation of genotypes at the non-HLA loci also provided additional associations, but none with stronger effects than the genotyped variants. An epistatic interaction between the IL12RB2 risk locus at 1p31and the IRF5 risk locus at 7q32 was also identified and suggests a complementary effect of these loci in predisposing to disease. These data expand the repertoire of genes with potential roles in PBC pathogenesis that need to be explored by follow-up biological studies.

Endoscopic submucosal dissection for treatment of gastric subepithelial tumors (with video).

BACKGROUND Endoscopic submucosal dissection (ESD) is a well-accepted method for removing superficial mucosal tumors; however, there is limited data on the use of this method for removing subepithelial tumors. OBJECTIVE To investigate the efficacy, safety, and outcome of ESD for gastric subepithelial tumors and determine factors related to treatment success. DESIGN Retrospective analysis of a prospectively maintained database. SETTING Single tertiary academic center. PATIENTS AND INTERVENTIONS From April 2007 to November 2010, 37 patients with gastric subepithelial tumors were treated with ESD. MAIN OUTCOME MEASUREMENTS Macroscopically and microscopically complete en block resection rate (R0), complication rate, and endosonographic features predictive of R0 resection. RESULTS The median tumor diameter was 25.0 mm, (range 10-60 mm, IQR 17-37). The overall rate of R0 resections was 81.1% (30/37, 95%CI: 61.8-90.2%), including 100% (15/15, 95%CI: 78.2-100.0%) of tumors from the submucosa and 68.2% (15/22, 95%CI: 45.1-86.1%) of tumors from the muscularis propria. Seventeen patients had a final diagnosis of gastrointestinal stromal tumor. The severe complication (perforation) rate was 5.4% (2/37, 95%CI: 0.0-9.5%). One patient required surgery; the other was treated conservatively. No recurrence was observed in patients with R0 resections at a median follow up of 21.0 months (IQR 11-35). Successful R0 resections were predicted by the observation of no, or only narrow, tumor connections with the underlying muscle layer during EUS (OR=35.0, 95%CI: 3.7-334.4, p=0.001). LIMITATIONS Single-center, retrospective analysis, short follow-up. CONCLUSIONS ESD is an effective and relatively safe method for removing gastric subepithelial tumors. Endoscopic ultrasonography findings can predict complete tumor resections.

Nodular regenerative hyperplasia: Evolving concepts on underdiagnosed cause of portal hypertension

Nodular regenerative hyperplasia (NRH) is a rare liver condition characterized by a widespread benign transformation of the hepatic parenchyma into small regenerative nodules. NRH may lead to the development of non-cirrhotic portal hypertension. There are no published systematic population studies on NRH and our current knowledge is limited to case reports and case series. NRH may develop via autoimmune, hematological, infectious, neoplastic, or drug-related causes. The disease is usually asymptomatic, slowly or non-progressive unless complications of portal hypertension develop. Accurate diagnosis is made by histopathology, which demonstrates diffuse micronodular transformation without fibrous septa. Lack of perinuclear collagen tissue distinguishes NRH from typical regenerative nodules in the cirrhotic liver. While the initial treatment is to address the underlying disease, ultimately the therapy is directed to the management of portal hypertension. The prognosis of NRH depends on both the severity of the underlying illness and the prevention of secondary complications of portal hypertension. In this review we detail the epidemiology, pathogenesis, diagnosis, management, and prognosis of NRH.

Impaired localisation and transport function of canalicular Bsep in taurolithocholate induced cholestasis in the rat.

Background: Taurolithocholate induced cholestasis is a well established model of drug induced cholestasis with potential clinical relevance. This compound impairs bile salt secretion by an as yet unclear mechanism. Aims: To evaluate which step/s of the hepatocellular bile salt transport are impaired by taurolithocholate, focusing on changes in localisation of the canalicular bile salt transporter, Bsep, as a potential pathomechanism. Methods: The steps in bile salt hepatic transport were evaluated in rats in vivo by performing pharmacokinetic analysis of 14C taurocholate plasma disappearance. Bsep transport activity was determined by assessing secretion of 14C taurocholate and cholyl-lysylfluorescein in vivo and in isolated rat hepatocyte couplets (IRHC), respectively. Localisation of Bsep and F-actin were assessed both in vivo and in IRHC by specific fluorescent staining. Results: In vivo pharmacokinetic studies revealed that taurolithocholate (3 μmol/100 g body weight) diminished by 58% canalicular excretion and increased by 96% plasma reflux of 14C taurocholate. Analysis of confocal images showed that taurolithocholate induced internalisation of Bsep into a cytosolic vesicular compartment, without affecting F-actin cytoskeletal organisation. These effects were reproduced in IRHC exposed to taurolithocholate (2.5 μM). Preadministration of dibutyryl-cAMP, which counteracts taurolithocholate induced impairment in bile salt secretory function in IRHC, restored Bsep localisation in this model. Furthermore, when preadministered in vivo, dibutyryl-cAMP accelerated recovery of both bile flow and bile salt output, and improved by 106% the cumulative output of 14C taurocholate. Conclusions: Taurolithocholate impairs bile salt secretion at the canalicular level. Bsep internalisation may be a causal factor which can be prevented by dibutyryl-cAMP.

Association of primary biliary cirrhosis with variants in the CLEC16A, SOCS1, SPIB and SIAE immunomodulatory genes

We fine mapped two primary biliary cirrhosis (PBC) risk loci, CLEC16A (C-type lectin domain family 16 member A)–suppressor of cytokine signaling 1 (SOCS1) and Spi-B protein (SPIB) and sequenced a locus, sialic acid acetylesterase (SIAE), proposed to harbor autoimmunity-associated mutations. In all, 1450 PBC cases and 2957 healthy controls were genotyped for 84 single-nucleotide polymorphisms (SNPs) across the CLEC16A-SOCS1 and SPIB loci. All 10 exons of the SIAE gene were resequenced in 381 cases and point substitutions of unknown significance assayed for activity and secretion. Fine mapping identified 26 SNPs across the CLEC16A-SOCS1 and 11 SNPs across the SPIB locus with significant association to PBC, the strongest signals at the CLEC16A-SOCS1 locus emanating from a SOCS1 intergenic SNP (rs243325; P=9.91 × 10−9) and at the SPIB locus from a SPIB intronic SNP (rs34944112; P=3.65 × 10−9). Among the associated SNPs at the CLEC16A-SOCS1 locus, two within the CLEC16A gene as well as one SOCS1 SNP (rs243325) remained significant after conditional logistic regression and contributed independently to risk. Sequencing of the SIAE gene and functional assays of newly identified variants revealed six patients with functional non-synonymous SIAE mutations (Fishers P=9 × 10−4 vs controls) We demonstrate independent effects on risk of PBC for CLEC16A, SOCS1 and SPIB variants, while identifying functionally defective SIAE variants as potential factors in risk for PBC.