Distribution of HLA-DR, HLA-DP, HLA-DQ antigens in liver tissue from patients with primary sclerosing cholangitis

HLA-DPA1*02:01~B1*01:01 is a risk haplotype for primary sclerosing cholangitis mediating activation of NKp44+ NK cells

OBJECTIVE

Primary sclerosing cholangitis (PSC) is characterised by bile duct strictures and progressive liver disease, eventually requiring liver transplantation. Although the pathogenesis of PSC remains incompletely understood, strong associations with HLA-class II haplotypes have been described. As specific HLA-DP molecules can bind the activating NK-cell receptor NKp44, we investigated the role of HLA-DP/NKp44-interactions in PSC.

DESIGN

Liver tissue, intrahepatic and peripheral blood lymphocytes of individuals with PSC and control individuals were characterised using flow cytometry, immunohistochemical and immunofluorescence analyses. HLA-DPA1 and HLA-DPB1 imputation and association analyses were performed in 3408 individuals with PSC and 34 213 controls. NK cell activation on NKp44/HLA-DP interactions was assessed in vitro using plate-bound HLA-DP molecules and HLA-DPB wildtype versus knock-out human cholangiocyte organoids.

RESULTS

NKp44+NK cells were enriched in livers, and intrahepatic bile ducts of individuals with PSC showed higher expression of HLA-DP. HLA-DP haplotype analysis revealed a highly elevated PSC risk for HLA-DPA1*02:01~B1*01:01 (OR 1.99, p=6.7×10-50). Primary NKp44+NK cells exhibited significantly higher degranulation in response to plate-bound HLA-DPA1*02:01-DPB1*01:01 compared with control HLA-DP molecules, which were inhibited by anti-NKp44-blocking. Human cholangiocyte organoids expressing HLA-DPA1*02:01-DPB1*01:01 after IFN-γ-exposure demonstrated significantly increased binding to NKp44-Fc constructs compared with unstimulated controls. Importantly, HLA-DPA1*02:01-DPB1*01:01-expressing organoids increased degranulation of NKp44+NK cells compared with HLA-DPB1-KO organoids.

CONCLUSION

Our studies identify a novel PSC risk haplotype HLA-DP A1*02:01~DPB1*01:01 and provide clinical and functional data implicating NKp44+NK cells that recognise HLA-DPA1*02:01-DPB1*01:01 expressed on cholangiocytes in PSC pathogenesis.

Immune-mediated cholangiopathies in children: the need to better understand the pathophysiology for finding the future possible treatment targets

Cholangiopathies are defined as focal or extensive damage of the bile ducts. According to the pathogenetic mechanism, it may be immune-mediated or due to genetic, infectious, toxic, vascular, and obstructive causes. Their chronic evolution is characterized by inflammation, obstruction of bile flow, cholangiocyte proliferation, and progression toward fibrosis and cirrhosis. Immune-mediated cholangiopathies comprise primary sclerosing cholangitis (PSC), autoimmune cholangitis and IgG4-associated cholangitis in adults and biliary atresia (BA), neonatal sclerosing cholangitis (NSC) in children. The main purpose of this narrative review was to highlight the similarities and differences among immune-mediated cholangiopathies, especially those frequent in children in which cholangiocyte senescence plays a key role (BA, NSC, and PSC). These three entities have many similarities in terms of clinical and histopathological manifestations, and the distinction between them can be hard to achieve. In BA, bile duct destruction occurs due to aggression of the biliary cells due to viral infections or toxins during the intrauterine period or immediately after birth. The consequence is the activation of the immune system leading to severe inflammation and fibrosis of the extrahepatic biliary tract, lumen stenosis, and impairment of the biliary flow. PSC is characterized by inflammation and fibrosis of intra- and extrahepatic bile ducts, leading to secondary biliary cirrhosis. It is a multifactorial disease that occurs because of genetic predisposition [human leukocyte antigen (HLA) and non-HLA haplotypes], autoimmunity (cellular immune response, autoantibodies, association with inflammatory bowel disease), environmental factors (infections or toxic bile), and host factors (intestinal microbiota). NSC seems to be a distinct subgroup of childhood PSC that appears due to the interaction between genetic predisposition (HLA B8 and DR3) and the disruption of the immune system, validated by elevated IgG levels or specific antibodies [antinuclear antibody (ANA), anti-smooth muscle antibody (ASMA)]. Currently, the exact mechanism of immune cholangiopathy is not fully understood, and further data are required to identify individuals at high risk of developing these conditions. A better understanding of the immune mechanisms and pathophysiology of BA, NSC, and PSC will open new perspectives for future treatments and better methods of preventing severe evolution.

Characteristics and predictive value for graft fibrosis of the complement-binding capacity of donor-specific human leukocyte antigen antibodies after pediatric liver transplantation

BACKGROUND

Donor-specific HLA antibodies (DSAs) have detrimental effects on short- and long-term outcomes after organ transplantation. Despite evidence that the complement-binding capacity of DSAs has predictive power in kidney transplantation, its clinical impact during long-term follow-up after LT remains unclear. In this study, we assessed the complement-binding capacities of DSAs and their association with histological findings.

METHODS

In total, 72 patients who underwent pediatric LT at our institution between July 1991 and October 2013 were retrospectively reviewed. A subgroup analysis of histological findings was performed for 37 subjects who underwent liver graft biopsy. Patients were divided into two groups based on the degree of graft fibrosis, and clinical characteristics were assessed.

RESULTS

All anti-class I DSAs were C1q-negative. Anti-DR and anti-DQ DSAs were identified in 34% and 41% of patients, respectively; however, only three of 25 patients with anti-DR DSAs exhibited a positive C1q-binding assay, whereas, 25 of 29 anti-DQ DSAs showed C1q-binding capacity. MFI values for DSA were significantly higher for patients with C1q-binding capacity than for those without (P < .0001). Complement-binding anti-DR DSA was relatively rare in both groups. Regarding anti-DQ DSA, there were no differences between fibrosis and non-fibrosis groups, irrespective of complement-binding capacity.

CONCLUSIONS

The association between anti-DR DSA and liver fibrosis, which was supported in this cohort, was not strengthened but rather impaired when accounting for complement-binding capacity due to low positive detection. Further studies of the association between complement-binding anti-DQ DSA and histological findings in LT are needed.

Antihistone Autoantibodies in Dobermans With Hepatitis

Background

Immune system involvement is suggested as an underlying cause for Doberman hepatitis (DH) based on female predisposition, lymphocyte infiltration, abnormal hepatocyte expression of major histocompatibility complex class II antigens, and homozygosity for dog leukocyte antigen DRB1*00601.

Objective

To measure serum antinuclear antibodies (ANA) and serum antihistone antibodies (AHA) in Dobermans with hepatitis. To determine whether increased serum ANA or serum AHA could be used to support the diagnosis of Doberman hepatitis (DH).

Animals

Privately owned 25 subclinically and 13 clinically affected DH Dobermans and 17 healthy control Dobermans.

Methods

Case–control study. Indirect immunofluorescence (IIF) microscopy and line blot tests were employed for the ANA pilot studies and an enzyme‐linked immunosorbent assay (ELISA) assay for detection of IgG AHA.

Results

Indirect immunofluorescence revealed ANA‐positive cases, and line blot showed AHA reactivity. In ELISA, importantly increased concentrations of AHA were found in 92% (23/25) of dogs in the subclinical stage and 84.6% (11 of 13) of dogs in the clinical stage of DH compared with no control dogs (0/17) (P < 0.0005). The mean AHA absorbance values of the blood samples obtained from the 25 subclinical DH dogs (1.36 ± 0.60, mean ± SD) and the 13 clinically affected dogs (1.46 ± 0.49) were significantly higher than in 17 control dogs (0.51 ± 0.18; P < 0.0001).

Conclusions and Clinical Importance

As the presence of AHA indicates autoimmune activity, our results favor an autoimmune background as one cause for DH. Antihistone antibody could represent a novel means for screening Dobermans with increased serum alanine transaminase concentrations and suspicion of DH.

Longterm renal allograft survival after sequential liver-kidney transplantation from a single living donor

Combined liver-kidney transplantation (CLKT) is well established as a definitive therapy with the potential to provide complete recovery for certain liver-kidney diseases, although the results might be contingent on the cause of transplantation. The purposes of the present study were to review the longterm outcome of renal allografts in CLKT patients from single living donors and to investigate the beneficial factors, compared with solitary renal transplantation. Thirteen patients underwent sequential liver transplantation (LT) and kidney transplantation (KT) from single living donors. The indications for KT were oxaluria (n = 7), autosomal recessive polycystic disease (n = 3), and others (n = 3). The same immunosuppressive regimen used after LT was also used after KT. KT was performed between 1.7 and 47.0 months after the LT. The overall patient survival rate was 92.3% at 10 years. In 12 of the 13 surviving patients, the renal allografts were found to be functioning in 11 patients after a mean follow-up period of 103.6 months. The death-censored renal allograft survival rate at 10 years was 100%, which was better than that of KT alone (84.9%) in Japan. Immunological protection conferred by the preceding liver allograft may have contributed to the longterm outcomes of the renal allografts. In addition, the donation of double organs from a single living and related donor may have a favorable impact on the graft survival rate. In the future, investigations of factors affecting the longterm outcome of renal allografts, including details of the involvement of de novo donor-specific antibody, will be needed. Liver Transplantation 23 315-323 2017 AASLD.

Four-year allograft survival in a highly sensitized combined liver-kidney transplant patient despite unsuccessful anti-HLA antibody reduction with rituximab, splenectomy, and bortezomib

Although donor-specific lymphocytotoxic antibodies are regarded as a contraindication for kidney transplantation (KTx), the data available for liver or combined liver or kidney transplantation (cLKTx) are scarce. Here, we report a case of a highly sensitized young man receiving his sixth liver and second kidney graft. Multiple anti-HLA antibodies were present at the time of transplantation. As a result of suspected antibody-mediated graft damage, the patient was treated with rituximab, plasmapheresis, intravenous immunoglobulins, splenectomy, and bortezomib to decrease the antibody production. So far, patient and allograft survival has reached 4 years despite failure to achieve a permanent reduction of anti-HLA antibodies, and particularly nondonor directed antibodies.

Genetics in primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a chronic cholestatic disorder with a progressive course. PSC is strongly associated with inflammatory bowel disease and is often complicated by cholangiocarcinoma development. Etiology and pathogenesis remain obscure, but the diverse clinical manifestation of the disease might, to some extent, indicate different genetic susceptibility in subgroups of patients. In recent years, genome-wide association studies performed in PSC have identified a number of genetic susceptibility loci. In this mini-review, we suggest that the genetic associations established can be grouped according to four pathogenic aspects relating to inflammation, cholangiocyte function, fibrosis and carcinogenesis. Subclassification of PSC patients according to their genetic predisposition could be a valuable tool in future functional and clinical studies.

Evaluation of DLA promoters in Doberman hepatitis

Doberman hepatitis (DH) is associated with homozygous DLA-DRB1*00601/DQA1*00401/DQB1*01303 indicating a role for the immune system in the development of the disease. The dog leucocyte antigen (DLA) class II expression is controlled at the transcriptional level with proximal promoters. Differential expression of DLA class II molecules of antigen-presenting cells is reported to affect susceptibility to or protection from different immune-mediated diseases. The aim of this study was to evaluate, whether the variation in promoter areas of homozygous DLA-DRB1*00601/DQA1*00401/DQB1*01303 Dobermans could explain why some dogs become afflicted with DH and others do not. Our findings suggest that promoter variants are not associated as risk modifiers in homozygous DLA-DRB1*00601/DQA1*00401/DQB1*01303 Dobermans, but additional factors are needed. Nevertheless, our study indicates that the whole DLA block is associated to the disease.

Association of Doberman hepatitis to canine major histocompatibility complex II

Doberman hepatitis (DH) is a chronic and progressive inflammatory liver disease that mainly affects female dogs. The high incidence of chronic hepatitis in Dobermans is suggestive of a genetic predisposition. DH is characterized by mononuclear cell infiltration and copper accumulation in the liver and major histocompatibility complex (MHC) class II antigen expression in the hepatocytes. In dogs, the MHC is referred to as the dog leukocyte antigen (DLA) system. In this study, the potential role of DLA genes in DH was investigated by sequence-based typing in the exon 2 of DLA-DRB1, -DQA1 and -DQB1. The case group comprised 37 Dobermans with subclinical or clinical DH. The control group consisted of 37 healthy Dobermans, with normal liver enzyme values and without immunosuppressive medication. The control dogs were over 10 years old to include dogs with the lowest genetic risk of DH. Our results indicate that Dobermans with homozygous DLA-DRB1*00601/DQA1*00401/DQB1*01303 [odds ratio (OR) = 14.9, confidence limit (CL) = 3.1-71.7, P < 0.00005], especially with homozygosity for DLA-DRB1*00601 (P < 0.0005), are susceptible to DH. The DQ heterodimer DLA-DQA1*00901/DQB1*00101 and the allele DLA-DRB1*01501 appear to confer protection against DH (P < 0.001). Allele and haplotype frequencies were compared using chi-squared statistics. The disease shows a complex pattern of inheritance, but the observed DLA class II association with DH suggests a role for the immune system in the development of the disease.

Etiopathogenesis of primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease of unknown etiology but lymphocytic portal tract infiltration is suggestive of an immune-mediated basis for this disease. Associations with inflammatory bowel disease (IBD) especially ulcerative colitis (UC), and with particular autoimmune diseases, as well as the genetic associations further suggest PSC may be an immune-mediated disease. The immunogenetics of PSC have been the subject of active research and several HLA and non-HLA associated genes have been implicated in the development of the disease. Lymphocytes derived from the inflamed gut may enter the liver via the enterohepatic circulation to cause hepatic disease. PSC may be triggered in genetically susceptible individuals by infections or toxins entering the portal circulation through a permeable colon and hence evoking an abnormal immune response.

A double-blind, placebo-controlled, randomized study of infliximab in primary sclerosing cholangitis

GOALS

To evaluate the safety and efficacy of infliximab in patients with primary sclerosing cholangitis.

STUDY

In this double-blind, placebo-controlled study, 24 patients with primary sclerosing cholangitis were screened and randomly assigned in a 2:1 ratio to receive infliximab (5 mg/kg) or placebo at weeks 0, 2, 6, 12, 18, and 24; patients were followed through week 52. The primary efficacy end point was a decrease of at least 50% in the serum alkaline phosphatase level from baseline to week 18. A blinded histologic assessment of liver biopsy samples, obtained at weeks 0 and 26, was performed using a predefined scoring system, including scores for inflammation, fibrosis, and cholestasis.

RESULTS

Patient enrollment was prematurely stopped when results of an interim analysis showed no significant treatment benefit. Of the 24 patients screened, 10 were enrolled (6 patients received infliximab). Mean alkaline phosphatase levels at weeks 0, 18, and 52 were 349, 330, and 389 U/L, respectively, for the infliximab group and 481, 438, and 391 U/L, respectively, for the placebo group. Liver biopsy samples were analyzed in 7 patients (4 infliximab); no apparent differences could be detected in any of the histologic parameters. In 3 of 4 infliximab-treated patients and 2 of 3 placebo-treated patients, the disease stage did not change after 6 months of treatment. No meaningful changes were detected in the symptom score. No serious drug-related adverse events were observed.

CONCLUSIONS

Study findings failed to demonstrate efficacy of infliximab in this small group of patients with established primary sclerosing cholangitis.

Human leukocyte antigen associations in Finnish liver transplantations due to primary sclerosing cholangitis and primary biliary cirrhosis

A genetic predisposition has been suggested in primary sclerosing cholangitis (PSC) and primary biliary cirrhosis (PBC). The aim of the study was to evaluate human leukocyte antigen (HLA) frequencies and HLA associations in Finnish PSC and PBC patients. The relative frequencies of HLA-A,-B, and-DR antigens were compared between patients with PSC (n=50), or PBC (n=89), transplanted due to end-stage liver disease, and healthy members in the Finnish bone marrow donor registry (n=10000). Prevalence differences, prevalence ratios and the associated large-sample significance probabilities (2-sided P-values) and 95% confidence intervals were calculated.

We found a strong positive association between PSC and HLA-B8 and-DR3, and a weak positive association between HLA-A1 and PSC. HLA-DR3 also had a weak positive association with PBC, and a weak negative association between HLA-DR5 and PBC was found. In conclusion, HLA-B8, and-DR3 are susceptible for progressive liver disease in PSC, and HLA-DR3 may also be susceptible for disease progression in PBC. HLA-DR5 may be protective against severe PBC.

Immunopathogenesis of primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease of unknown etiology;however, lymphocytic portal tract infiltration is suggestive of an immune-mediated basis for PSC. Associations with inflammatory bowel disease--especially ulcerative colitis--and with other auto-immune diseases, together with genetic associations, further suggest that PSC may be an immune-mediated disease. The immunogenetics of PSC have been the subject of active research, and several human leukocyte antigen (HLA)- and non-HLA-associated genes have been implicated in the development of the disease. Lymphocytes derived from the inflamed gut may enter the liver via the enterohepatic circulation to cause hepatic disease.PSC may be triggered in genetically susceptible individuals by infections or toxins entering the portal circulation through a permeable colon and, therefore, evoking an abnormal immune response.

Expression of adhesion molecules on mature cholangiocytes in canal of Hering and bile ductules in wedge biopsy samples of primary biliary cirrhosis

AIM: To examine the expression of intercellular adhesion molecule-1 (ICAM-1) and lymphocyte function-associated antigen-1 (LFA-1) expression on canals of Hering (CoH) and bile ductules associated with the autoimmune process of bile duct destruction in primary biliary cirrhosis (PBC).

METHODS: Ten wedged liver biopsies of PBC (five cases each of stages 2 and 3) were studied. The liver specimens were processed for transmission electron microscopy. Immunohistochemistry was performed using anti-ICAM-1 and anti-LFA-1 mouse mAbs. In situ hybridization was done to examine the messenger RNA expression of ICAM-1 in formalin-fixed, paraffin-embedded sections using peptide nucleic acid probes and the catalyzed signal amplification (CSA) technique. Immunogold-silver staining for electron microscopy was performed using anti-ICAM and anti-LFA-1 mouse mAbs. The immunogold particles on epithelial cells of bile ductules and cholangiocytes of CoH cells were counted and analyzed semi-quantitatively. Western blotting was performed to confirm ICAM-1 protein expression.

RESULTS: In liver tissues of PBC patients, immunohi-stochemistry showed aberrant ICAM-1 expression on the plasma membrane of epithelial cells lining bile ductules, and also on mature cholangiocytes but not on hepatocytes in CoH. LFA-1-positive lymphocytes were closely associated with epithelial cells in bile ductules. ICAM-1 expression at protein level was confirmed by Western blot. In situhybridization demonstrated ICAM-1 mRNA expression in bile ductules and LFA-1 mRNA in lymphocytes infiltrating the bile ductules. By immunoelectron microscopy, ICAM-1 was demonstrated on the basal surface of epithelial cells in bile ductules and on the luminal surfaces of cholangiocytes in damaged CoH. Cells with intermediate morphology resembling progenitor cells in CoH were not labeled with ICAM-1 and LFA-1.

CONCLUSION: De novo expression of ICAM-1 both on mature cholangiocytes in CoH and epithelial cells in bile ductules in PBC implies that lymphocyte-induced destruction through adhesion by ICAM-1 and binding of LFA-1-expressing activated lymphocytes takes place not only in bile ductules but also in the CoH.

Review article: current management of primary sclerosing cholangitis

The management of primary sclerosing cholangitis (PSC) is hindered by incomplete understanding of the pathogenesis of the disease and the lack of good prognostic models. Few large randomized controlled trials of drug therapy have been published. Best practice in the management of PSC is currently based therefore on careful interpretation of the available evidence, close observation of individual patients and clinical experience of the disease. Drug therapy is useful for alleviating symptoms. Ursodeoxycholic acid may slow progression of the disease and reduce the frequency of complications. Consensus is emerging on the issues of screening for the malignant complications of PSC and the indications for liver transplantation are becoming broader and encompassing the earliest stages of cholangiocarcinoma. In view of the rarity of the disease in the general population, large international collaborations to study PSC are necessary to provide clearer answers in areas of uncertainty, and these are now beginning to emerge.

Primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a fibrosing disease of the intra- and extra-hepatic bile ducts, and is closely associated with inflammatory bowel disease. It is immune mediated, rather than being a classical autoimmune disease. A range of immune abnormalities have been demonstrated in PSC, in particular the findings of a range of autoantibodies, a portal tract infiltrate of functional T cells, a restricted T-cell receptor repertoire, and aberrant expression of HLA molecules on biliary epithelial cells. The immunogenetics of PSC is currently under study and to date 4 key HLA haplotypes associated with PSC have been developed. The trigger factor for the initiation of the immune response may be the ingress of bacteria or other toxic metabolites into the portal circulation through a diseased and permeable bowel wall.

Upregulation of major histocompatibility complex class II antigens in hepatocytes in Doberman hepatitis

Major histocompatibility complex (MHC) class II antigen expression in hepatocytes and its correlation with mononuclear cell infiltration into the liver were studied using immunohistochemical techniques in 38 Dobermans with Doberman hepatitis (DH). Liver biopsy samples were obtained from 18 dogs at the subclinical stage. Autopsy samples were taken from 6 DH dogs euthanized for a reason other than DH, from 14 dogs euthanized because of advanced liver failure and from 6 control Dobermans. Upon examination of the control liver samples, no expression of MHC class II antigens was detected in hepatocytes. By contrast, in 15 of the 18 DH biopsies (83%) and in all 20 DH autopsy liver samples, hepatocytes expressed MHC class II molecules. MHC class II expression was either cytoplasmic or membranous and occurred in conjunction with lymphocyte infiltration. A correlation between the inflammatory reaction and the expression of MHC class II in hepatocytes suggests that the aberrant expression of MHC class II in hepatocytes is induced by cytokines. Hepatocytes presenting a putative MHC class II molecule-associated autoantigen could thus become the target of an immune attack mediated by CD4+ T cells. In addition, corticosteroid treatment was observed to significantly decrease MHC class II expression in DH hepatocytes. Inappropriate MHC class II expression in hepatocytes and mononuclear cell infiltration are suggesting an autoimmune nature for chronic hepatitis in Dobermans.

Immunopathogenesis of cholestatic autoimmune liver diseases

Primary biliary cirrhosis and primary sclerosing cholangitis are well recognized chronic cholestatic liver diseases that are considered to have an autoimmune basis. Recent progress in the study of autoimmune liver diseases has improved the recognition and characterization of these conditions. An important component of this progress has been the identification of liver disease-associated autoantibodies and their respective target antigens, and the development of specific assays for these autoantibodies. In addition, some nonhumoral immunological findings imply an involvement of specific immunopathogenic mechanisms in the development of these conditions. Furthermore, immunogenetic factors associated with increased susceptibility to some of these diseases have been identified. This article reviews the most relevant information relating to the postulated autoimmune pathogenesis of these diseases, with special emphasis on their associated humoral and cellular immunological abnormalities and immunopathogenetic factors. Some of the remaining important unresolved issues relating to the pathogenesis of these diseases, that need to be addressed in further research, are highlighted.

Primary biliary cirrhosis and primary sclerosing cholangitis

Primary biliary cirrhosis and primary sclerosing cholangitis are the most common chronic cholestatic liver diseases in adults that lead to biliary cirrhosis and its inherent complications such as portal hypertension and liver failure. Although important advances in the understanding of the pathogenesis of these conditions have been accomplished in the last two decades, much work is needed to uncover the interaction of genetic and immunologic mechanisms involved in their pathogenesis. Ursodeoxycholic acid at dosage of 13 to 15 mg/kg/d is the only agent that can currently be recommended in the treatment of PBC. No medical therapy aimed at disrupting disease progression is available for patients with primary sclerosing cholangitis, although several agents with different properties are currently under evaluation. Liver transplantation is the treatment of choice for patients with primary biliary cirrhosis and primary sclerosing cholangitis with end-stage liver disease.

Hepatobiliary manifestations of inflammatory bowel disease

PSC is the most common of the clinically significant hepatobiliary diseases seen in association with IBD, with an incidence that varies from 2.5% to 7.5%. Conversely, 50% to 75% of patients with PSC have IBD. This high degree of association suggests a common pathogenetic mechanism; however, no causal relationship has been established. The etiopathogenesis of PSC remains poorly understood, despite a large number of studies looking at differing hypotheses. The diagnosis is usually established by cholangiography. Liver biopsy can sometimes be helpful in diagnosing pericholangitis. There is a significant overlap of the histology with chronic hepatitis. Serum markers have been studied for diagnosing PSC, particularly for early diagnosis of cholangiocarcinoma, but none have shown the high sensitivity and specificity needed to use them clinically. PSC usually progresses insidiously and eventually leads to cirrhosis. Despite progress in early recognition, optimal management of patients with PSC remains a challenge requiring a multidisciplinary approach among hepatologists, endoscopists, surgeons, and interventional radiologists. Colectomy for ulcerative colitis does not alter the natural history of PSC. There is a high (10% to 15%) incidence of cholangiocarcinoma in patients with PSC. This incidence along with the risk of colon cancer in patients with ulcerative colitis makes it necessary to follow these patients closely. A number of pharmacologic therapies have been evaluated, but none has proven successful in slowing the progression of PSC or prolonging survival. Endoscopic therapy has a proven utility in treating complications of recurrent cholangitis or worsening jaundice in the setting of a dominant stricture, but endoscopy has not been shown to improve survival or decrease the need for liver transplantation. Liver transplantation is life-saving for patients with advanced PSC. Pericholangitis, gallstones, and chronic hepatitis are additional disorders noted in association with IBD, but they are much less common and easier to manage than PSC.

Cytokine production from colonic T cells in patients with ulcerative colitis with and without primary sclerosing cholangitis

PURPOSE

Only five percent of all patients with ulcerative colitis develop primary sclerosing cholangitis. T cells accumulate at the sites of the colonic and bile duct inflammation in both ulcerative colitis and primary sclerosing cholangitis. T helper cell populations comprise functionally distinct subsets characterized by the cytokines they produce. Several alterations in cytokine production have been described in patients with ulcerative colitis. The aim of this study was to investigate possible differences in T helper subsets and cytokine production in peripheral blood and colonic mucosa among ulcerative colitis patients with and without primary sclerosing cholangitis.

METHODS

Eleven patients with primary sclerosing cholangitis and extensive ulcerative colitis, 11 patients with extensive ulcerative colitis and no liver disease, and 5 patients without any history of liver disease who underwent routine colonoscopy because of previous polypectomy were included in the study. Colonoscopy with multiple biopsies was performed on all patients. Lamina propria mononuclear cells and peripheral blood mononuclear cells were isolated. A modified version of solid-phase enzyme-linked immunospot assay was used for the separate counting of cells producing interferon-gamma, interleukin-2 (T helper 1), and interleukin-4 (T helper 2).

RESULTS

No differences in spontaneous production of cytokines from peripheral blood mononuclear cells was found among the three groups. Patients with primary sclerosing cholangitis compared with patients with ulcerative colitis without liver disease showed a significant increase in the number of cells secreting interferon-gamma after purified protein derivative stimulation (P < 0.02). More cells secreting interferon-gamma were found in the two ulcerative colitis groups than in the cell populations from healthy controls (P < 0.03). The number of cells secreting interferon-gamma in the primary sclerosing cholangitis group was significantly lower than in the ulcerative colitis group without liver disease (P < 0.04). The number of cells secreting interleukin-4 was lower in the primary sclerosing cholangitis group than among the patients with ulcerative colitis only (P = 0.05).

CONCLUSION

Isolated lymphocytes from colonic mucosa differ in cytokine production in patients with ulcerative colitis with and without primary sclerosing cholangitis.

Primary sclerosing cholangitis: a clinical review

Primary sclerosing cholangitis (PSC) is a cholestatic liver disease characterized by fibro-obliterative inflammation of the entire biliary tree. It is a slowly progressive disease with an undulating course, resulting in terminal biliary cirrhosis after a median period of about 12 years after diagnosis. The etiology of the disease is unknown and there is no effective therapy that can halt disease progression. Around 8% of PSC patients develop cholangiocarcinoma, which, by the time it is diagnosed, cannot be treated curatively. The purpose of this article is to review the current knowledge about primary sclerosing cholangitis and to speculate on future strategies to address the issues of etiology and therapy.

Patterns of intermediate filaments, VLA integrins and HLA antigens in a new human biliary epithelial cell line sensitive to interferon-gamma

BACKGROUND/AIMS

Intra-hepatic bile ducts are the primary site of damage in several immunologically mediated liver diseases. However, immunological processes underlying biliary epithelial cell recognition by T lymphocytes are poorly understood. Therefore, a convenient in vitro model that could mimic these immunologic disorders would be of great interest.

METHODS

A human cell line (HuGB) was established from a metastasis of gallbladder adenocarcinoma in the liver. Intermediate filament expression was analysed by immunostaining, and gamma-glutamyl transpeptidase and albumin secretion were measured. VLA integrin expression pattern, expression of HLA class I and II antigens and ICAM-1 protein were analysed by flow cytometry and their modulation by interferon-gamma was quantitated using a QIFIKIT commercial kit.

RESULTS

Histological analysis showed high similarity between the initial gallbladder adenocarcinoma and the established cell line. Cytokeratins 8 and 19 and vimentin showed strong positive staining in the established cell line. Gamma-glutamyl transpeptidase was secreted by these cells while albumin expression was negative. HuGB cells also expressed VLA-alpha2, VLA-alpha3, VLA-alpha6, VLA-beta1, but not VLA-alpha1, VLA-alpha4 and NCAM, a pattern of adhesion molecule expression compatible with the biliary epithelium. Also, similar to the biliary epithelium found in normal liver, HuGB cells expressed abundant HLA class I but few HLA class II antigens. We found that the expression of HLA antigens and ICAM-1 protein were increased during interferon-gamma treatment of HuGB cell line.

CONCLUSIONS

Both phenotypic and morphological characteristics of HuGB cells suggested their biliary origin. Sensitivity of HuGB cells to interferon-gamma suggests that this new cell line could represent a suitable model to investigate the up-regulation of membrane antigens occurring in immune diseases involving biliary epithelial cells.

Preferential V beta3 usage by hepatic T lymphocytes in patients with primary sclerosing cholangitis

BACKGROUND/AIMS

Primary sclerosing cholangitis and primary biliary cirrhosis are two biliary destructive disorders characterized by prominent T lymphocyte infiltrates in areas of portal destruction. The specificity of the T cell is determined by the T cell receptor for antigens. The aim of this study was to investigate the preference by which certain V alpha and V beta gene segments are expressed by peripheral and hepatic T cells in primary sclerosing cholangitis and primary biliary cirrhosis.

METHODS

The usage of the alpha/beta T cell receptor (TcR) V gene of liver infiltrating lymphocytes and peripheral blood lymphocytes from 12 primary sclerosing cholangitis patients, 10 primary biliary cirrhosis patients and healthy controls was investigated, using alpha/beta TcR V gene product-specific monoclonal antibodies. HLA class II antigen typing with genomic typing technique was done in 11/12 primary sclerosing cholangitis patients.

RESULTS

A significant difference between the studied groups of patients was an increase in the expression of V beta3+ T cells in liver tissue from patients with primary sclerosing cholangitis compared to patients with primary biliary cirrhosis and healthy controls (p<0.01). No significant differences were found in the peripheral blood between the three groups. Furthermore, no relation between the different TcR V alpha/beta cells and histological staging and class II antigen association was observed.

CONCLUSIONS

Predominant TcR V beta3 gene usage in liver tissue in primary sclerosing cholangitis may indicate the presence of a specific antigen in this tissue with the capacity of selectively driving T cells, utilizing the V beta3 gene segment product, in primary sclerosing cholangitis patients.

Liver transplantation for sclerosing cholangitis

The clinical course of 37 patients who underwent 46 liver transplantations for primary (n = 33) and secondary (n = 4) sclerosing cholangitis was reviewed. The median follow-up was 37 months. The patient and graft survivals for patients with primary sclerosing cholangitis at 1, 2, and 5 years were 96.9%, 91.6%, 87.9%, and 83.1%, 74.2%, 65.2%, respectively. In the patients with primary sclerosing cholangitis (PSC), prior surgery except for simple cholecystectomy was associated with significantly greater operative time and blood loss. No cholangiocarcinoma was identified at the time of transplantation. Human leukocyte antigen typing for PSC patients was heavily weighed toward B8 (58.8%) compared with control (11.8%). Sixty-two percent of patients with PSC also had inflammatory bowel disease. Moderate or severe rejection requiring OKT3, "rescue therapy" with FK506, or retransplantation was relatively higher in patients with inflammatory bowel disease (70%) versus patients without inflammatory bowel disease (36.4%) and a matched control group (37.5%). Progressive inflammatory bowel disease was seen in 6 of 19 patients, with 3 developing cancer and a dysplasia. Two patients in the entire group died of sepsis and 3 of colon cancer (2 recurrent and 1 primary). These data demonstrate that excellent survival results can be achieved in this group of patients. Rejection is frequent and often severe and steroid refractory. Colon cancer represents the most frequent cause of death in PSC patients after liver transplantation and demands constant attention.

HLA-DR expression in liver in human HIV infection

In order to clarify the relationship between HLA-DR antigen expression in the liver and human HIV infection, we studied 66 non-autopsy specimens obtained from HIV-infected patients with and without AIDS; 33 biopsies from HIV-negative patients were considered for control purposes. All biopsies were immunohistochemically tested with monoclonal antibody TAL-1B5, reacting with the alpha-chain subunit of HLA-DR in the avidin biotin complex method. We found occasional and usually weak HLA-DR expression on hepatocytes and biliocytes. By comparison with controls, HIV-positive cases showed a significantly higher percentage of HLA-DR immunoreactivity on hepatic artery and portal vein endothelial cells. No relationship was demonstrated between HLA-DR endothelial expression and the CD4+ lymphocyte count or grade of portal/periportal inflammation in the liver. The biological significance of HLA-DR expression on intrahepatic vascular endothelial cells in HIV infection still remains to be clarified.

Adhesion molecule expression in primary sclerosing cholangitis and primary biliary cirrhosis

There are conflicting reports regarding intercellular adhesion molecule-1 (ICAM-1) expression in primary sclerosing cholangitis (PSC) and primary biliary cirrhosis (PBC). Expression of adhesion molecules ICAM-1, lymphocyte adhesion molecule-1 (LFA-1), vascular cell adhesion molecule (VCAM), and E-selectin was examined together with HLA-DR in 16 liver biopsy specimens showing PSC and 12 specimens showing PBC. These were compared with biopsy specimens showing large duct obstruction (n = 7), chronic active hepatitis (n = 4), alcoholic liver disease (n = 4), and normal liver histological results (n = 5). ICAM-1 was detected on biliary epithelium in five of seven PSC specimens of histological stage 3 or 4, but not in nine early PSC specimens or in specimens from disease controls. In PBC, ICAM-1 was positive on three of 12 cases, two stage 2, and one stage 3. Nine of 16 PSC specimens (three of nine early, six of seven late disease) and six of 10 PBC specimens (three early, three late disease) were positive for HLA-DR. LFA-1 stained infiltrating inflammatory cells in PSC, PBC, and disease controls. In conclusion, ICAM-1 expression on biliary epithelium in PSC occurs mainly in late stage disease and therefore may be secondary to previous events inducing inflammation rather than of primary pathogenic importance. ICAM-1 expression in PBC is less common and not clearly associated with a particular disorder. Previous reports of ICAM-1 prevalence may have been biased towards end stage, pre-transplantation biopsy specimens.

Current concepts in primary sclerosing cholangitis

OBJECTIVE

To describe primary sclerosing cholangitis (PSC) and its associated complications, as well as medical and surgical treatment.

DESIGN

A review of PSC and its associated etiopathologic factors is presented; numerous studies of agents that are used to treat patients with PSC are discussed.

RESULTS

PSC, a slowly progressive disease that often involves autoimmune damage to the biliary tree, is frequently associated with inflammatory bowel disease, usually chronic ulcerative colitis. Long-term follow-up of patients with PSC has revealed a high incidence of colon cancer and bile duct cancer, both of which are most likely related to the chronic inflammation involving these two organs. Although PSC is an unusual disease, it is now diagnosed with approximately the same frequency as is primary biliary cirrhosis. The histopathologic evolution of PSC results in irreversible damage to bile ducts, which ultimately leads to cholestasis, cirrhosis, liver failure, and premature death from liver failure unless liver transplantation is performed. Therefore, the best chance of achieving success is to treat patients with early-stage disease rather than those with irreversible end-stage cirrhotic disease. Although several medical therapies for PSC have been evaluated, only D-penicillamine, cyclosporine, methotrexate, and, most recently, ursodeoxycholic acid have been studied in controlled clinical trials. Furthermore, several surgical therapies for PSC and its associated complications have been assessed.

CONCLUSION

Currently, no therapy achieves a complete clinical, biochemical, or histologic remission in this disease. Until the etiopathogenesis of PSC is further defined, effective therapy is unlikely to be found. Thus, liver transplantation will continue to be an important therapeutic intervention for the management of patients with end-stage PSC.

Etiology and pathogenesis in primary sclerosing cholangitis

The etiology and pathogenesis of the inflammatory and fibrotic bile duct lesions characteristic of primary sclerosing cholangitis (PSC) is unknown, but several lines of evidence support the contention that genetic and immunologic factors are involved. There is an association with human leukocyte antigens (HLA) with an increased frequency of DR3, DR6, and DR2 positive haplotypes. DRB3*0101(DR52a) is the most strongly associated allele in some studies, but the HLA gene conferring the primary HLA associated susceptibility to PSC remains to be established. There is an aberrant expression of HLA class II antigens (DR and DP) on bile duct epithelial cells, with the potential to present antigens to the surrounding T-lymphocytes. A defective suppressor T-cell function has been suggested in some studies. The patients may have elevated levels of circulating immune complexes, immunoglobulins, and non-organ-specific autoantibodies. Antibodies to perinuclear antigens (pANCA) are present in about 80% of cases. Increased metabolism of complement C3, reduced clearance of immune complexes, and increased concentration of biliary immune complexes have been found. The strong association between PSC and ulcerative colitis (UC) has not been explained. The detection of circulating IgG antibodies against a specific epitope shared by epithelial cells in the bile ducts and colon in about two-thirds of PSC patients may be of importance. Portal bacteremia secondary to a diseased bowel may possibly contribute to development of liver disease in UC. Viral infections and toxic and ischemic factors have also been implicated in the pathogenesis of PSC. In conclusion, PSC seems to occur in genetically predisposed individuals, mediated by immunologic mechanisms. The primary event triggering the disease development is, however, unknown.

Induced expression of heat-shock protein on biliary epithelium in patients with primary sclerosing cholangitis and primary biliary cirrhosis

In both primary sclerosing cholangitis and primary biliary cirrhosis it is supposed that immunological mechanisms are involved in the progressive destruction of the bile ducts. The aberrant expression of human leukocyte antigen-DR in the bile ducts of patients with these disorders enables the biliary epithelium to present putative antigens to the surrounding lymphocytes; however, no such antigen has been identified. Heat-shock proteins have been implicated in the pathogenesis of various immunological destructive disorders. Liver biopsy specimens from patients with primary biliary cirrhosis (n = 10) and primary sclerosing cholangitis (n = 13) were compared with those from patients with chronic hepatitis C infection (n = 5) and alcoholic cirrhosis (n = 4) and from normal controls (n = 6). Liver sections were investigated by means of immunohistochemical study using a mouse monoclonal antibody, ML30, directed against the 65-kD heat-shock protein of Mycobacterium, with monoclonal antibody against human leukocyte antigen-DR and with the monoclonal antibody Identi-Tr TCR delta 1, which recognizes a determinant on the delta-chain of the gamma/delta form of the human T-cell receptor. Human leukocyte antigen-DR expression was found on the biliary epithelium of all primary sclerosing cholangitis and primary biliary cirrhosis patients but not on bile ducts from patients with alcoholic cirrhosis or chronic hepatitis C infection or those from normal controls. The biliary epithelium reacted with ML30 in 9 of 10 primary biliary cirrhosis patients and in all primary sclerosing cholangitis patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Lack of concomitant expression of ICAM-1 and HLA-DR on bile duct cells from patients with primary sclerosing cholangitis and primary biliary cirrhosis

In both primary biliary cirrhosis (PBC) and primary sclerosing cholangitis (PSC) prominent infiltrates of lymphocytes surround the bile ducts, on which an abberrant expression of major histocompatibility complex class II antigens has been found, suggesting that the immune system is involved in the biliary destruction. Since the lymphocytes presumably must adhere to the bile ducts to initiate a cell-to-cell-mediated destruction, we have studied the expression of the lymphocyte function-associated antigen-1 (LFA-1) together with its ligand, the intercellular adhesion molecule-1 (ICAM-1), and the expression of HLA-DR, using immunoperoxidase staining of cryostat sections from patients with PBC (n = 10), PSC (n = 13), and normal healthy controls (n = 6). Most lymphocytes expressed LFA-1. ICAM-1 expression was found on hepatocytes from 9 of 10 PBC and 10 of 13 PSC patients but was not seen on hepatocytes from the controls. Hepatocytes expressing HLA-DR were only found in one patient with PBC. None of the septal bile ducts expressed ICAM-1, and only one PSC patient and three PBC patients expressed ICAM-1 on their interlobular bile ducts. The bile ducts in 22 of 23 patients, however, expressed HLA-DR. Proliferating bile ductules from two PBC patients and three PSC patients showed a concomitant expression of ICAM-1 and HLA-DR. None of the bile ducts from the controls expressed ICAM-1 or HLA-DR.(ABSTRACT TRUNCATED AT 250 WORDS)

Primary sclerosing cholangitis in patients with ulcerative colitis

The prevalence of primary sclerosing cholangitis (PSC) in patients with ulcerative colitis (UC) attending the Depts. of Medical and Surgical Gastroenterology, Aalborg Hospital, during a 12-year period, was determined. All patients with an alkaline phosphatase (ALP) value above the normal range were investigated. Of 305 patients with UC, 24 patients had elevated ALP values, and 11 of these (3.6% of the study population), 4 males and 7 females, were found to have PSC by direct cholangiography. In five patients the disease worsened (two patients died of cholangiocarcinoma), in four it was stationary, and in two patients the disease improved during a mean observation period of 6 years. No differences in location of disease, disease activity, or duration of disease were found between patients with UC and PSC and patients with UC without PSC. The ALP values were raised to a mean of 3.7 times the upper normal limit (observed range, 1.5-5.5 times the upper normal limit). Aspartate aminotransferase was moderately elevated in most patients, but no other abnormal biochemical liver test results were observed at onset. The results of our study indicate that PSC is the major cause of raised ALP values in patients with UC; thus cholangiography should be performed in UC patients with unexplained elevated ALP levels. A prognostic indicator is needed to predict the individual prognosis and to determine the optimal timing of liver transplantation.

Primary sclerosing cholangitis

Primary sclerosing cholangitis is a condition of unknown cause. It is recognized by liver dysfunction and its characteristic radiologic appearance, which is related to portal tract inflammation, bile duct proliferation, and periductal fibroses involving small intrahepatic and large extrahepatic ducts. The disease lasts about 10 years from the time of diagnosis. Primary sclerosing cholangitis is recognized by abnormal results on routine liver function tests or by the development of clinical jaundice. An autoimmune cause has been suggested because of its strong association with inflammatory bowel disease, certain antigens, AIDS, and immunoregulatory abnormalities. Results of medical management of sclerosing cholangitis have been disappointing. Immunosuppressive drugs, copper chelating agents, and antibiotics have failed to alter progression of the disease. Colectomy in patients with inflammatory bowel disease also has no influence. The judicious use of dilations of strictures, bypass procedures, or resection can palliate jaundice in patients with primary sclerosing cholangitis, but liver transplantation is the definitive treatment. Because palliative operations increase the hazards of liver transplantation, percutaneous dilations and stentings are preferred initially. Cirrhosis and portal hypertension are indications for transplantation. In the future, transplantation may be indicated earlier in the course of the disease.