HLA DR4 is a marker for rapid disease progression in primary sclerosing cholangitis

Autoimmune Liver Diseases and Rheumatoid Arthritis-Is There an Etiopathogenic Link?

Rheumatoid arthritis (RA) is a systemic immune-mediated disease that, in addition to the articular involvement, can have extra-articular manifestations. Even though liver damage in RA is not very common, associated autoimmune liver diseases (AILDs) may occur. The most common AILD associated with RA is primary biliary cirrhosis (PBC), followed by autoimmune hepatitis (AIH) and primary sclerosing cholangitis (PSC). There are common underlying mechanisms that play a role in the emergence of autoimmunity and inflammation in both rheumatic and autoimmune liver diseases. Genetic studies have revealed the existence of several common disease-associated genes shared between RA and AILDs, and infectious triggers, particularly those associated with recurrent or complicated urinary tract infections, are also speculated to be potential triggers for these conditions. Moreover, these diseases share common serologic patterns characterized by the presence of specific autoantibodies and hyper-gammaglobulinemia. In this study, we focus on reviewing the association between RA and AILDs regarding the prevalence and possible etiopathogenic link.

Diagnostic considerations for cholestatic liver disease

Cholestatic liver disease results from insufficient bile synthesis, secretion and/or flow through the biliary tract. Common presenting features include fatigue, pruritus, and cholestatic liver enzyme abnormalities wherein elevations of serum alkaline phosphatase and gamma-glutamyltransferases levels exceed those of alanine and aspartate aminotransferases. With prolonged cholestasis, fat soluble vitamin deficiencies, fibrosis, cirrhosis, and, on occasion, carcinoma of the biliary tract or liver can occur. Once mechanical obstruction to bile flow has been ruled out, the majority of causes can be classified as immune-mediated, infectious, or miscellaneous. Because specific therapeutic options are increasing for many causes of cholestasis, an accurate diagnosis is an important first step towards treatment. Thus, this review focuses on the diagnostic features of non-mechanical causes of cholestasis.

Pathogenesis and clinical spectrum of primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a disease of the biliary tract, which has been documented in the literature since 1867. This disease has a strong predilection for affecting men and can be seen in individuals as young as 2 years of age. PSC has a strong associated with inflammatory bowel disease, more commonly with ulcerative colitis, and is also part of the clinical spectrum of IgG4-related diseases. Small-duct PSC, a variant of PSC, also has an association with inflammatory bowel disease. The exact pathogenesis of PSC is not well understood at present, however, is likely a combination of a genetic predisposition with alteration of the molecular structure of the gut. Abnormal serum liver chemistry and presence of certain autoimmune markers are usually the first indicators leading to a diagnosis of PCS, however, these may often be normal in early stages of this disease. The diagnosis is made by cholangiography, which is now considered the gold standard. PSC is a known pre-malignant condition. Such patients have an increased risk of developing cholangiocarcinoma, gallbladder neoplasia, and colon cancer. Many new treatment modalities have emerged in the recent past, including anti-tumor necrosis factor- α and anti-integrins; however, liver transplantation is the only known cure for PSC. Despite past and present research, PSC remains an enigmatic biliary disease with few viable treatment options.

Primary Biliary Cirrhosis and Primary Sclerosing Cholangitis: a Review Featuring a Women's Health Perspective

Primary biliary cirrhosis (PBC) and primary sclerosing cholangitis (PSC) are two major types of chronic cholestatic liver disease. Each disorder has distinguishing features and variable progression, but both may ultimately result in cirrhosis and hepatic failure. The following offers a review of PBC and PSC, beginning with a general overview of disease etiology, pathogenesis, diagnosis, clinical features, natural course, and treatment. In addition to commonly associated manifestations of fatigue, pruritus, and fat-soluble vitamin deficiency, select disease-related topics pertaining to women's health are discussed including metabolic bone disease, hyperlipidemia and cardiovascular risk, and pregnancy-related issues influencing maternal disease course and birth outcomes. This comprehensive review of PBC and PSC highlights some unique clinical considerations in the care of female patients with cholestatic liver disease.

Advances and controversies in the pathogenesis and management of primary sclerosing cholangitis

INTRODUCTION

Primary sclerosing cholangitis (PSC) is a chronic immune-mediated liver disease that results in end-stage liver disease requiring liver transplantation. PSC is closely associated with inflammatory bowel disease (IBD) with 70% of patients with PSC also suffering from IBD.

SOURCES OF DATA

Data for this review were obtained from PubMed.

AREAS OF AGREEMENT

Historical and genome-wide association studies have established a strong human leukocyte antigen (HLA) linkage to PSC and defined specific haplotypes associated with enhanced PSC risk. Fifteen non-HLA loci have been defined in PSC.

AREAS OF CONTROVERSY

The biological role of risk loci in PSC and their place in PSC pathogenesis remain speculative but suggest significant interactions with the host microbiome and therapeutic opportunities.

GROWING POINTS

Genetics provides a platform to systematically target emerging therapies in PSC.

AREAS TIMELY FOR DEVELOPING RESEARCH

Linking PSC genotypes with biology and disease phenotypes paves the way for a personalized medicine approach to manage PSC.

Diagnosis and classification of primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a chronic cholestatic disease of the liver and that is characterized by progressive inflammation, fibrosis, and stricturing of the intrahepatic and extrahepatic bile ducts. It is progressive in most patients and leads to cirrhosis. It is a rare disease, mostly affecting people of northern European descent, males greater than females. The diagnosis is best established by contrast cholangiography, which reveals a characteristic picture of diffuse, multifocal strictures and focal dilation of the bile ducts, leading to a beaded appearance. Inflammatory bowel disease (IBD) is present in ~75% of the patients with PSC, mostly ulcerative colitis (~85% of the cases). In addition to biliary cirrhosis, complications of PSC include dominant strictures of the bile ducts, cholangitis, cholangiocarcinoma, colon dysplasia and cancer in patients with IBD, gallbladder polyps and cancer, and hepatic osteodystrophy. The etiology of PSC is not clear, but studies are ongoing. The median survival without liver transplantation is 12 to 15 years after diagnosis. Currently there are no effective treatments except liver transplantation. Immunosuppressive medications have not been shown to be effective but antibiotics and anti-fibrotic agents seem promising.

Pathogenesis of primary sclerosing cholangitis and advances in diagnosis and management

Primary sclerosing cholangitis (PSC), first described in the mid-1850s, is a complex liver disease that is heterogeneous in its presentation. PSC is characterized by chronic cholestasis associated with chronic inflammation of the biliary epithelium, resulting in multifocal bile duct strictures that can affect the entire biliary tree. Chronic inflammation leads to fibrosis involving the hepatic parenchyma and biliary tree, which can lead to cirrhosis and malignancy. The etiology of PSC is not fully understood, which in part explains the lack of effective medical therapy for this condition. However, we have begun to better understand the molecular pathogenesis of PSC. The recognition of specific clinical subtypes and their pattern of progression could improve phenotypic and genotypic classification of the disease. We review our current understanding of this enigmatic disorder and discuss important topics for future studies.

HLA and autoimmune digestive disease: a clinically oriented review for gastroenterologists

OBJECTIVES

The human leukocyte antigen (HLA) system includes genes involved in graft-vs-host rejection and in immune response. The discovery that HLAs are associated with several diseases led to appealing developments both in basic biomedical research and in clinical medicine, and offered the opportunity to improve the understanding of pathogenesis and classification of diseases, as well as to provide diagnostic and prognostic indicators. The aim of this article is to review the association between HLA alleles and autoimmune digestive disease and its current relationship with modern HLA nomenclature and clinical practice.

METHODS

Articles dealing with the association between HLAs and autoimmune digestive disease (including celiac disease, inflammatory bowel disease, autoimmune hepatitis, sclerosing cholangitis and primary biliary cirrhosis) were searched for using Pubmed and SCOPUS databases from earliest records to January 2008.

RESULTS

The review has provided two sections. In the first, we explain the basic principles of HLA structure, function, and nomenclature, as an introduction to the second section, which describes current associations between HLA alleles and digestive diseases. The clinical implications of each HLA association are critically discussed. Actually, a clinical role for HLA typing is suggested for only a few conditions, e.g., celiac disease.

CONCLUSIONS

The knowledge of current HLA nomenclature and of its association with some digestive diseases such as celiac disease can be useful in clinical practice for diagnostic and prognostic purposes. This can avoid improper HLA typing as well as stressing the need for further studies on other possible clinical applications.

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.

Current diagnosis and management of primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is an important liver disease with major morbidity and mortality. The diagnosis of PSC is confirmed by magnetic resonance cholangiopancreaticography, and endoscopic retrograde cholangiopancreaticography is performed in patients needing therapeutic endoscopy. As a result of the unknown cause of the disease, current medical therapies are unsatisfactory. Nevertheless, high-dose ursodeoxycholic acid should be recommended for treatment of PSC patients because there is a trend toward increased survival. Dominant bile duct stenoses should be treated endoscopically. However, liver transplantation continues to be the only therapeutic option for patients with advanced disease. Estimation of prognosis and timing of liver transplantation should be determined individually for each PSC patient on the basis of all results. The diagnosis and treatment of cholangiocarcinoma (CC) still remain a challenge in PSC patients. Early diagnosis of CC certainly is a prerequisite for successful treatment with surgical resection or innovative strategies such as neoadjuvant radiochemotherapy with subsequent orthotopic liver transplantation. Therefore, endoscopic techniques such as cholangioscopy and/or intraductal ultrasound may be useful diagnostic tools in patients with stenoses suspicious for malignancy.

Primary sclerosing cholangitis is associated with extended HLA-DR3 and HLA-DR6 haplotypes

Primary sclerosing cholangitis (PSC) is associated with the human leukocyte antigen (HLA)-DRB1*0301-DQA1*0501-DQB1*0201 (DR3) and HLA-DRB1*1301-DQA1*0103-DQB1*0603 (DR6) haplotypes. Recently, the extended HLA class I region has been found to harbour genes that modulate or confer susceptibility independently of the HLA class II genes in several immune-mediated diseases. The aim of the present study was to evaluate the influence of genes in the extended HLA class I region on susceptibility to PSC. Seven microsatellite markers (MIB, D6S265, D6S2222, D6S464, D6S2223, D6S2225 and D6S2239) were analysed together with HLA class II alleles in 219 Norwegian patients with PSC and 282 random controls. To control for associations because of linkage disequilibrium (LD), 142 HLA-DR3 homozygous and 187 DR6-positive controls were included. The unstratified analysis showed significant associations with the alleles MIB*349 [odds ratio (OR) = 3.0, corrected P value (P(c)) = 3 x 10(-12)], D6S265*122 (OR = 1.7, P(c)= 0.004), D6S464*209 (OR = 1.8, P(c)= 0.03) and D6S2225*147 (OR = 2.7, P(c)= 4 x 10(-6)), which were mainly secondary to the DR3 association. When stratifying for DR6, an association with the D6S265*122 allele was still observed (OR = 3.7, P(c)= 0.0004). In the presence of the D6S265*122 allele, the risk to develop PSC conferred by DR6 was increased four times compared with the risk conferred by DR6 alone. In addition, a novel negative association of PSC with DR11 was observed (OR = 0.21, P(c)= 2 x 10(-4)). In conclusion, our study shows that a gene in LD with D6S265 contributes to susceptibility to develop PSC in individuals carrying DR6. Moreover, we found that the PSC-associated DR3 haplotype extends more telomeric than that previously reported. We also report a possible protective effect of DR11 on development of PSC.

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.

Characterization, outcome, and prognosis in 273 patients with primary sclerosing cholangitis: A single center study

OBJECTIVES

Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease with varying severity and progression. This study describes the natural history of PSC patients and evaluates the prognostic significance of clinical, biochemical, and cholangiographic findings constructing a novel prognostic model.

METHODS

A population of 273 German PSC patients was studied with a median follow-up time of 76 months (range 1-280 months). Survival curves were analyzed by the Kaplan-Meier method, and prognostic significance of clinical, biochemical, and cholangiographic features recorded at the time of diagnosis was evaluated by multivariate analysis using Cox proportional-hazards regression models.

RESULTS

The estimated median survival from the time of diagnosis to death or time of liver transplantation was 9.6 yr. One hundred eight (39.6%) patients underwent liver transplantation. Hepatobiliary malignancies were found in 39 (14.3%) patients of the entire PSC population. Age, low albumin, persistent bilirubin elevation longer than 3 months, hepatomegaly, splenomegaly, dominant bile duct stenosis, and intra- and extrahepatic ductal changes at the time of diagnosis were found to be independent risk factors correlating with poor prognosis and were used to construct a new prognostic model.

CONCLUSIONS

A persistent bilirubin elevation for longer than 3 months from the time of diagnosis could be identified as a novel marker correlating with a poor outcome. A new prognostic model was developed to predict progression of PSC, which may be useful in timing of liver transplantation.

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.

Primary sclerosing cholangitis and hepatitis C virus infection

Two cases of primary sclerosing cholangitis with hepatic C virus infection in a 62-year-old man and a 60-year-old woman are presented. The infection in the man was eradicated with interferon therapy in 1992. Seven years thereafter, endoscopic retrograde cholangiography revealed a diffuse 2.5-cm-long stenotic lesion in the common bile duct which was consequently resected. Histological examination of the resected specimen revealed proliferation of epithelial cells, plasma cell infiltration, and fibrosis in the submucosal layer of the common bile duct. The human leukocyte antigen DR loci were 2 and 9. In the woman, a 6-month course of interferon therapy in 1992 failed to eradicate the infection. Cholangiography in 1999 revealed multiple narrowings and dilatations of intra- and extrahepatic bile ducts. Ultrasound guided biopsy of the liver in 1992 had revealed onionskin lesions around the bile duct epithelium in the portal tract. The human leukocyte antigen DR locus was 2. From these findings, the 2 cases were diagnosed as primary sclerosing cholangitis. Further studies may provide insights into the relation between the pathogenesis of the disease and the infection.

Primary sclerosing cholangitis: Updates in diagnosis and therapy

Primary sclerosing cholangitis (PSC) is a chronic cholestatic syndrome of unknown origin mostly found in males, and characterized by diffuse inflammation and fibrosis of both intra- and extra-hepatic bile ducts. So far, PSC is considered as an autoimmune hepatobiliary disease. In most cases the progression of PSC towards liver cirrhosis and liver failure is slow but irreversible, and liver transplantation is currently the only definitive treatment. In recent years, PSC has been an area of active research worldwide with great interest in etiology, pathogenesis, diagnosis, and therapeutic options such as hydrophilic ursodeoxycholic acid and immunosuppressive agent tacrolimus. Recent updates on clinical and therapeutic aspects of PSC are discussed in the present review.

Primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease characterized by inflammation and fibrosis of the intra- and extrahepatic bile ducts. An estimated 80% of patients in North America and Europe have coexistent inflammatory bowel disease (IBD). The underlying pathophysiology of PSC remains poorly understood. As a result, there is currently no effective medical therapy to halt disease progression. Important complications from PSC include metabolic bone disease, colorectal neoplasia, and cholangiocarcinoma. Liver transplantation remains the only successful treatment option for patients with advanced liver disease from PSC. A diagnosis of PSC should be considered among individuals with IBD and elevated serum liver biochemical tests.

Susceptibility to primary sclerosing cholangitis is associated with polymorphisms of intercellular adhesion molecule-1

BACKGROUND/AIMS

Intercellular adhesion molecule-1 (ICAM-1, CD54) gene polymorphisms have been implicated in the susceptibility to a range of inflammatory diseases, including inflammatory bowel disease (IBD). Primary sclerosing cholangitis (PSC) is an immune-mediated chronic cholestatic liver disease associated with IBD. ICAM-1 is expressed on proliferating bile ducts and interlobular bile ducts in late stage PSC and serum levels of soluble intercellular adhesion molecules are increased in PSC. The aim of this study was to analyse ICAM-1 gene polymorphisms in PSC patients.

METHODS

In this study, 104 patients with PSC and 213 healthy controls were recruited from Oxfordshire Caucasians. PCR with sequence-specific primers (PCR-SSP) was used to detect both ICAM-1 biallelic polymorphisms G241R and K469E. The results were controlled for the HLA haplotypes associated with PSC.

RESULTS

The E/E frequency of K469E in PSC was 12% (12/104), significantly lower than that in controls (24%, 51/213;P = 0.009; Pc = 0.02; OR, 0.41). The occurrence of the haplotype G241-E469/G241-E469 in PSC was 4% (4/104), significantly lower than the control group (13%, 28/213; P = 0.01; Pc = 0.04; OR, 0.26). There was no difference between PSC and control groups in the frequencies of the genotype R241G or in allele frequencies of K469E.

CONCLUSIONS

The E469E homozygote status for ICAM-1 is associated with protection against PSC.

Primary sclerosing cholangitis

Primary sclerosing cholangitis is a cholestatic liver disease strongly associated with IBD. Considerable advances in the understanding of its pathogenesis have been made. The idea of autoimmunity affecting genetically susceptible individuals is largely accepted; however, much remains to be explained about the origin of this disease. Despite active investigation of different therapeutic modalities with the goal of modifying disease progression, liver transplantation continues to be the only option to provide survival benefit in these patients.

Epidemiology of autoimmune liver disease

Primary biliary cirrhosis (PBC), autoimmune hepatitis (AIH) and primary sclerosing cholangitis (PSC) are chronic liver diseases that likely have an autoimmune basis to their pathogenesis. Although significant strides have been made in the clinical management of these conditions, their pathogenesis remains obscure. Understanding of various epidemiological factors may shed light on predisposing or causative factors for these diseases. Most is known about the epidemiology of PBC, with only minimal information on that of PSC and AIH. In this review, the current data on the epidemiology of PBC, AIH and PSC are summarized and suggestions are made for future work in this important area.

Novel association of HLA-haplotypes with primary sclerosing cholangitis (PSC) in a southern European population

AIMS

In patients with with primary sclerosing cholangitis we investigated the major histocompatibility complex (MHC) genes and mutations of the cystic fibrosis transmembrane conductance regulator (CFTR) gene.

METHODS

In 64 PSC patients and 183 normal controls of the same population (Northern Italy), allelic polymorphisms at the DNA level were investigated in MHC region genes: HLA-DRB1, HLA-DQB1 and HLA-B, tumour necrosis factor A (TNFA), and in CFTR gene, with polymerase chain reaction-based methodologies.

RESULTS

Frequencies of DRB1*01, DQA1*0101, DQB1*0102 (14 vs. 8%, p<0.05), DRB1*16, DQA1*0102, DQB1*0502 (8 vs. 3%, p<0.025) and DRB1*04, DQA1*03, DQB1*0301 (10 vs. 4%, p<0.005) haplotypes were more elevated in PSC patients. The frequency of patients positive for HLA DRB1*01, *1601 or *04 related haplotypes was significantly increased (32 vs. 14%, p<0.00025). DRB1*07, DQA1*0201, DQB1*02 haplotype frequency was significantly decreased (4 vs. 15%, p<0.001). After removing HLA-DRB1*01, *1601, *04 related haplotype sharing patients, HLA-DRB1*03, DQA1*0501, DQB1*02 haplotype frequency was significantly increased (32 vs. 14%, p<0.01). TNFA2 allele frequency was significantly increased in PSC patients (23 vs. 14%, p<0.025), as well as the TNFA2 homozygous genotype (9 vs. 0.5%, p=0.0013). No mutations were found on the CFTR gene and the allelic frequency of the 5T polymorphism in intron 8 was not increased.

CONCLUSION

These data suggest that the role of genes in the HLA region is relevant, but not necessarily disease-specific and it might be different in populations with divergent ancestries.

Hepatic manifestations of gastrointestinal diseases. Inflammatory bowel disease, celiac disease, and Whipple's disease

The gastrointestinal tract and the liver are closely related anatomically, physiologically, and pathologically. Some disease associations are well documented, such as PSC in association with IBD, whereas others are less well defined. A heightened clinical suspicion is required in these patients who do not present with the classical disease associations. The underlying causes of their diseases are the subject of much debate and research, and their diagnosis and management remain challenging.

Hepatobiliary disease in inflammatory bowel disease

Many hepatobiliary diseases are seen in IBD. PSC is the most common, occurring in 7.5% of patients with UC. The cause of PSC is not well understood, but PSC seems to be associated with genetic susceptibility, sharing some immunologic abnormalities with UC. A characteristic cholangiogram in a patient with abnormal liver function tests usually establishes the diagnosis. Liver biopsy is not essential but can help make the diagnosis of small duct PSC in patients with a normal cholangiogram. There are no medications that treat PSC effectively. Endoscopic dilation of dominant strictures reduces the frequency of cholangitis and may improve survival. OLT remains the only proven treatment of advanced PSC. Cholangiocarcinoma is a feared complication of PSC that is difficult to diagnose. Cholelithiasis, PBC, portal vein thrombosis, and hepatic abscess are hepatobiliary disorders that occur less frequently in IBD patients.

Aetiopathogenesis of primary sclerosing cholangitis

The aetiology and pathogenesis of PSC have not yet been clearly defined. The hypothesis that PSC is an immune mediated disease is supported by associations with HLA haplotypes, the presence of autoantibodies, increased levels of total serum immunoglobulins and the association with other autoimmune diseases. PSC does not, however, have many of the characteristics of classical autoimmunity, particularly the usual female preponderance of disease and lack of a good response to immunosuppression. Non-immune mechanisms such as bacterial infection, ischaemia and toxicity are also clearly important in the development of the disease and these factors may trigger peribiliary inflammation and cytokine-induced hepatic fibrosis. PSC may be triggered in genetically susceptible individuals by toxic or infectious agents gaining access to the liver via a diseased and permeable colon.

Immunogenetics in PSC

Primary sclerosing cholangitis (PSC) does not exhibit simple Mendelian inheritance attributable to a single gene locus and our knowledge of the genetics of this complex disease is based entirely on case-control studies of candidate genes. The prime candidates in PSC are inherited variation (polymorphism) in the genes that regulate the immune response, especially the genes of the major histocompatability complex (MHC). Thus far, five different human leukocyte antigen (HLA) haplotypes have been associated with PSC: three with increased risk of disease and two with reduced risk. More recently studies of non-MHC genes have failed to associate PSC with several cytokine genes (IL-1 and IL-10), with FAS (TNFRSF6), with TGFbeta-1, or with CCR-5 but have found genetic links with MMP-3 and disease progression, whilst the potential role of CTLA-4 gene polymorphism remains in question. With the completion of the human genome project, understanding the genetics of complex (non-Mendelian) disease is a major priority for the research community and the studies summarized herein may guide these future investigations.

Association of the tumour necrosis factor alpha -308 but not the interleukin 10 -627 promoter polymorphism with genetic susceptibility to primary sclerosing cholangitis

BACKGROUND AND AIMS

Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease of unknown aetiology. Abnormalities in immune regulation and genetic associations suggest that PSC is an immune mediated disease. Several polymorphisms within the tumour necrosis factor alpha (TNF-alpha) and interleukin 10 (IL-10) promoter genes have been described which influence expression of these cytokines. This study examines the possible association between polymorphisms at the -308 and -627 positions in the TNF-alpha and IL-10 promoter genes, respectively, and susceptibility to PSC.

METHODS

TNF-alpha -308 genotypes were studied by polymerase chain reaction (PCR) in 160 PSC patients from Norway and the UK compared with 145 ethnically matched controls. IL-10 -627 genotypes were studied by PCR in 90 PSC patients compared with 84 ethnically matched controls.

RESULTS

A total of 16% of Norwegian PSC patients and 12% of British PSC patients were homozygous for the TNF2 allele compared with 3% and 6% of respective controls. The TNF2 allele was present in 60% of PSC patients versus 30% of controls (OR(combined data)=3.2 (95% confidence intervals (CI) 1.8--4.5); p(corr)=10(-5)). The association between the TNF2 allele and susceptibility to PSC was independent of the presence of concurrent inflammatory bowel disease (IBD) in the PSC patients; 61% of PSC patients without IBD had TNF2 compared with 30% of controls (OR(combined data)=3.2 (95% CI 1.2--9.0); p(corr)=0.006 ). There was no difference in the -627 IL-10 polymorphism distributions between patients and controls in either population. The increase in TNF2 allele in PSC patients only occurs in the presence of DRB1*0301 (DR3) and B8. In the combined population data, DRB1*0301 showed a stronger association with susceptibility to PSC than both the TNF2 and B8 alleles (OR(combined data)=3.8, p(corr)=10(-6) v OR(combined data)=3.2, p(corr)=10(-5) v OR(combined data )=3.41, p(corr)=10(-4), respectively).

CONCLUSIONS

This study identified a significant association between possession of the TNF2 allele, a G-->A substitution at position -308 in the TNF-alpha promoter, and susceptibility to PSC. This association was secondary to the association of PSC with the A1-B8-DRB1*0301-DQA1*0501-DQB1*0201 haplotype. No association was found between the IL-10 -627 promoter polymorphism and PSC.

Mapping MHC-encoded susceptibility and resistance in primary sclerosing cholangitis: the role of MICA polymorphism

BACKGROUND & AIMS

Recent studies suggest that major histocompatibility complex-encoded susceptibility to primary sclerosing cholangitis (PSC) maps to the HLA B-TNFA region on chromosome 6p21.3.

METHODS

The present study uses a standard polymerase chain reaction protocol to investigate the 16 common alleles of the MICA locus as candidates in 2 patient populations (King's College Hospital, London, and John Radcliffe Hospital, Oxford).

RESULTS

The MICA*002 allele was found in 4 of 62 (6.4%) patients and none of 50 patients vs. 41 of 118 (35%) controls (pc = 0.00018, odds ratio [OR] = 0.12, and P = 0.0000016, OR = 0.0, respectively). Overall, the MICA*008 allele was more common in PSC (gene frequency 66% vs. 48% of controls, P = 0.0023, OR = 2.11). However, unlike MICA*002 in which the difference was a result of the absence of MICA*002 heterozygotes, the MICA*008 association may be caused by an increased frequency of MICA*008 homozygosity in patients (58% vs. 22%, pc = 0.000015, OR = 5.01 and 58% vs. 22%, P = 0.0000056, OR = 4.51, respectively). Though MICA*008 is found on the ancestral 8.1 haplotype, stratification analysis indicates that this association is independent of B8 and other HLA haplotypes associated with PSC.

CONCLUSIONS

The MICA*002 allele has a strong dominant effect in reducing the risk of PSC, whereas the increased risk of disease associated with MICA*008 may be a recessive effect requiring 2 copies of the MICA*008 allele.

Association of HLA-DR genes with mild idiopathic adulthood biliary ductopenia

OBJECTIVE

Mild idiopathic adulthood ductopenia (MIAD) is an asymptomatic chronic cholestatic liver disease characterized by the loss of interlobular bile ducts in <50% of the portal tracts. Although the underlying cause of MIAD is unknown, the host factors may contribute to the patient's susceptibility to the disease. The aim of this work was to investigate the immunogenetics in the pathogenesis of MIAD.

METHODS

We prospectively studied 22 Caucasian patients with MIAD. Peripheral blood was collected, and HLA-DR typing was performed by polymerase chain reaction with sequence-specific primers followed by sequencing for subtyping. Results were compared with those from 140 age- and sex-matched controls.

RESULTS

There was no significant association between HLA-DRB1 alleles and the disease, although a trend was found in MIAD patients with the DRB1*1502 allele (five of 44 vs four of 280 in controls; p corrected = 0.055; chi2 = 13.9). Multiple HLA-DRB1 alleles (*04, *11, *15) showed increased frequencies in MIAD patients. Further subtyping revealed a motif (positions 25-32 of the beta1 chain) present in 17 (77.3%) patients, which was significantly associated with MIAD (p = 0.049; chi2 = 3.87). Seven patients (31.8%) and 21 (15%) controls coded for this motif in their two alleles (p = 0.068; chi2 = 3.76). Among MIAD patients, those seven had abnormal ALT levels (p = 0.017) and their gamma-glutamyltransferase and ALT values tended to be more increased.

CONCLUSIONS

These results provide evidence of an immunogenetic basis of susceptibility to MIAD in Caucasian individuals.

Primary sclerosing cholangitis associated with rheumatoid arthritis and HLA DR4: is the association a marker of patients with progressive liver disease?

In four cases we describe the unique association of primary sclerosing cholangitis (PSC) and rheumatoid arthritis (RA). In three of the cases the liver disease was unusually progressive, proceeding to cirrhosis in 14, 18 and 48 months from diagnosis. The three cases with progressive liver disease and ulcerative colitis were all HLA type DR4. The fourth patient also suffered from coeliac disease in addition to PSC and RA and has remained asymptomatic over 7 years of follow-up. RA in association with PSC may serve as a clinical marker of patients at high risk of progression to cirrhosis who need to be kept under particularly close observation. In addition, PSC needs to be considered in the differential diagnosis of all patients with RA and cholestatic liver function tests. This is especially important given the link between PSC and an increased risk of colonic carcinoma, and thus the need for surveillance colonoscopy.

Increased frequency of autoimmune diseases in patients with primary sclerosing cholangitis

OBJECTIVES

Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease of unknown origin that mostly affects male patients with inflammatory bowel disease (IBD). The immune system is believed to be involved in the etiology/pathogenesis as these patients present with several immunological disturbances. Susceptibility to develop primary sclerosing cholangitis is partly determined by genes in the HLA complex. The aim of this study was to compare the prevalence of autoimmune disorders in IBD patients with and without PSC and to correlate the presence of autoimmune disorders in PSC to outcome and HLA association.

METHODS

One hundred nineteen PSC patients were included in the study. Each PSC patient with IBD was matched to a IBD patient without PSC. The presence of autoimmune disorders was carefully evaluated in each group. Moreover, comparisons between PSC patients with and without autoimmune disorders were performed.

RESULTS

Twenty-five percent of the PSC patients had at least one autoimmune disorder outside the liver and colon compared to 9% in the IBD group without PSC (p < 0.005). Nine of the PSC patients had two or more autoimmune diseases compared to only one patient in the IBD group (p < 0.02). The PSC patients with and without associated autoimmune disease did not differ in clinical presentation, outcome of PSC or HLA alleles. A significant overrepresentation of DRB1*03 was still present after excluding PSC patients with concomitant autoimmune diseases outside the liver and colon compared to a healthy Swedish control group.

CONCLUSIONS

Autoimmune disorders are more frequent among PSC patients compared to IBD patients without liver disease. Associated autoimmune diseases in PSC patients does not influence the outcome or clinical presentation of PSC.

Budesonide or prednisone in combination with ursodeoxycholic acid in primary sclerosing cholangitis: a randomized double-blind pilot study. Belgian-Dutch PSC Study Group

OBJECTIVE

PSC has characteristics of an (auto)immune-mediated disease: however, few studies have evaluated corticosteroid therapy for this disorder.

METHODS

We performed an 8-wk double-blind randomized pilot study to assess the effects of additional treatment with 9 mg budesonide (n = 6) versus 3 mg budesonide (n = 6) versus 10 mg prednisone (n = 6) in patients who had been treated with UDCA (mean dose, 12 mg/kg/day) for at least 5 months without achieving biochemical remission. Pruritus and fatigue were evaluated using visual analog scales. Serum liver biochemistry was measured every 4 wk. At entry and at the end of the trial, adrenocorticotrophic hormone (ACTH) and dehydroepiandrosterone (DHEA) were measured to assess effects on the pituitary-adrenal axis. Duodenal bile was collected for assessment of biliary corticosteroid activity.

RESULTS

Pruritus decreased significantly more in the prednisone group compared to both the 3-mg and the 9-mg budesonide groups (p < 0.05). Alkaline phosphatase (mean: -23.4%; p = 0.03) and IgG (mean: -16.2%; p = 0.04) decreased in the prednisone group, whereas bilirubin, gamma-glutamyl transferase, aspartate aminotransferase, and alanine aminotransferase did not change significantly. No significant clinical or liver biochemical changes were observed in the 3-mg and 9-mg budesonide groups. Significantly larger drops in serum ACTH were found in the 10-mg prednisone group (-40.7%; p = 0.04) and 9-mg budesonide group (-36.6%; p = 0.02) compared to the 3-mg budesonide group (+ 19.0%). No significant differences in percentage change in baseline values for DHEA between the three treatment arms were found. Mononuclear cell proliferation assays did not demonstrate corticosteroid activity in bile. Autoimmune hepatitis was observed in one case (9 mg budesonide) when corticosteroids were tapered off.

CONCLUSION

The results of this pilot study suggest only minor beneficial short-term effects of prednisone but not budesonide on symptoms and serum liver tests in UDCA-treated PSC patients.

The interleukin-1 and interleukin-10 gene polymorphisms in primary sclerosing cholangitis: no associations with disease susceptibility/resistance

BACKGROUND/AIMS

Although primary sclerosing cholangitis is believed to be an autoimmune disorder, no tissue-specific auto-antibodies have yet been identified, and the strongest support for an autoimmune aetiology comes from HLA-association studies. Three different HLA haplotypes are associated with susceptibility to the disease and one with protection from it. These HLA haplotypes, however, do not account for all of the disease risk and genes outside the HLA region may also have a role in disease pathogenesis. The aim of this study was to investigate, for the first time, polymorphic genes/sites within the interleukin-1 and interleukin-10 genes in a large well-characterised group of patients.

METHODS

Ninety-six patients and 96 control subjects were studied. A single base-exchange polymorphism at position +3953 in the first exon of the IL-1B gene, a penta-allelic repeat sequence in the IL-1 receptor antagonist gene (IL-1RN) and three single base-exchange polymorphisms at positions -592, -819 and -1082 in the IL-10 gene promoter were determined by standard PCR-based techniques.

RESULTS

Overall, there was no significant difference in the distribution of any of the IL-1B, IL-1RN or IL-10 alleles or genes sequences comparing patients and controls. In addition, there was no difference when the patients were stratified for the presence and absence of the HLA DRB1*0301 (DR3) allele or concurrent inflammatory bowel disease.

CONCLUSION

Neither the IL-1B +3953, IL-1RN microsatellites polymorphisms on chromosome 2q13 nor the IL-10 -592, -819, -1082 promoter gene polymorphisms on chromosome 1q31-32 are associated with susceptibility or resistance to primary sclerosing cholangitis.

Chronic cholestatic diseases

Chronic cholestatic diseases, whether occurring in infancy, childhood or adulthood, are characterized by defective bile acid transport from the liver to the intestine, which is caused by primary damage to the biliary epithelium in most cases. In this article, approaches to diagnosis and management of the main specific disorders are provided and some of the recent developments in this field are discussed. Major advances in the understanding of the cellular and molecular physiology of bile secretion have led to identification of genetic defects responsible for the different types of progressive familial intrahepatic cholestasis (PFIC). The potential role of the genes involved in PFIC in some adult cholestatic disorders remains to be determined. The majority of adult patients with chronic cholestasis have primary biliary cirrhosis (PBC) or primary sclerosing cholangitis (PSC). Recently, variant forms of PBC have been described. The term autoimmune cholangitis is used to describe patients having chronic non-suppurative cholangitis with negative antimitochondrial antibodies (AMA) but positive antinuclear and/or antismooth muscle antibodies. Autoimmune cholangitis and AMA-positive PBC are quite similar in terms of clinical presentation, survival and response to ursodeoxycholic acid (UDCA) therapy. In contrast, autoimmune cholangitis must be distinguished from PBC-autoimmune hepatitis (AIH) overlap syndrome in which biochemical and histological characteristics of both PBC and AIH coexist. Combination of UDCA and corticosteroids is required in most patients with overlap syndrome to obtain a complete clinical and biochemical response. Long-term UDCA treatment improves survival without liver transplantation in PBC patients. Among the putative mechanisms of the beneficial effects of UDCA, description of anti-apoptotic properties and effect on endotoxin disposal in biliary cells have provided new insights. In patients with incomplete response to UDCA, combination of UDCA with antiinflammatory or immunosuppressive drugs is under evaluation. Variant forms of PSC have also been described, including PSC-AIH overlap syndrome, especially in children or young adults, and small-duct PSC, which is characterized by normal cholangiogram in patients having chronic cholestasis, histologic features compatible with PSC and inflammatory bowel disease. Development of cholangiocarcinoma (CC) is a major feature of PSC, occurring in 10-15% of patients. Early diagnosis of CC is a difficult challenge, although positron emission tomography seems a promising tool. Unlike PBC, effective medical therapy is not yet available in PSC, reflecting the lack of knowledge about the exact pathogenesis of the disease. Currently, liver transplantation is the only effective therapy for patients with advanced disease, although recurrence of PSC in the graft may occur.

Primary biliary cirrhosis, primary sclerosing cholangitis, and autoimmune cholangitis

Primary biliary cirrhosis (PBC), and autoimmune cholangitis are presumed to be autoimmune cholestatic diseases, but the relevant antigens are unknown. Primary biliary cirrhosis is diagnosed by a positive serum mitochondrial antibody test. It usually affects women and has a very long course, culminating in liver transplantation or death. Ursodeoxycholic acid is probably the appropriate treatment. Primary sclerosing cholangitis (PSC) is marked by progressive destruction of extrahepatic and intrahepatic bile ducts. There is no specific diagnostic test or treatment. Cholangiocarcinoma is the dreaded complication and precludes liver transplantation, the only chance of a cure. Autoimmune cholangitis overlaps PBC and autoimmune chronic hepatitis. It is a rare condition, resembling PBC but with a negative serum mitochondrial antibody test; however, serum antinuclear antibodies and smooth muscle antibodies are present in high titers.

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.

Primary sclerosing cholangitis in children

Primary sclerosing cholangitis (PSC), a chronic inflammatory process affecting the extrahepatic and/or medium to large bile ducts, is not rare in children. It has features suggesting an autoimmune pathogenesis, although the mechanism of tissue damage remains unknown. The clinical presentation of childhood primary sclerosing cholangitis is highly variable and frequently without obvious features of cholestasis. Clinical similarity to autoimmune hepatitis is common. Association with chronic colitis is less common than in adults. Cholangiography is essential for the diagnosis and examination of the medium to large intrahepatic ducts is mandatory, as 40% of children lack extrahepatic duct involvement. Histological findings may help to distinguish childhood PSC from autoimmune hepatitis. In children, sclerosing cholangitis may also develop secondary to other disease processes, notably Langerhans histiocytosis, congenital immunodeficiencies and cystic fibrosis. Neonatal sclerosing cholangitis is chronic inflammatory disease of bile ducts which presents initially with neonatal cholestasis; its pathogenesis remains uncertain and may not be the same as for primary sclerosing cholangitis. Effective treatment modalities for childhood PSC remain undetermined. Liver transplantation is required for children who progress to biliary cirrhosis and hepatic decompensation.

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.

HLA class II haplotypes in primary sclerosing cholangitis patients from five European populations

The association of primary sclerosing cholangitis (PSC) to HLA class II genes was studied by comparing patients from five different European populations. Deduced HLA-DRB1, DQA1, DQB1 haplotypes of 256 PSC patients from England, Italy, Norway, Spain and Sweden were compared to those observed in 764 ethnically-matched controls. Increased frequencies of the DRB1*03, DQA1*0501, DQB1*02 (RR=3.0, P<0.00001) and the DRB1*13, DQA1*0103, DQB1*0603 haplotypes (RR=2.4, P<0.0001) were observed in all five patient groups. A total of 16% of the PSC patients were homozygous for the DRB1*03, DQA1*0501, DQB1*02 haplotype compared to 1% of the controls (RR=20, P<0.0001). The DRB1*04, DQA1*03, DQB1*0302 haplotype was significantly reduced in frequency(RR=0.4, P<0.00001). Among Norwegian, Swedish and British patients that did not carry neither the DRB1*03, DQA1*0501, DQB1*02 nor the DRB1*13, DQA1*0103, DQB1*0603 haplotype, an increased frequency of the DRB1*15, DQA1*0102, DQB1*0602 haplotype was observed (RR=2.0, P<0.0001). Thus, PSC was found to be positively associated to three different HLA class II haplotypes (i.e. the DRB1*03, DQA1*0501, DQB1*02, the DRB1*15, DQA1*0102, DQB1*0602 and the DRB1*13, DQA1*0103, DQB1*0603 haplotypes) and negatively associated to one HLA class II haplotype (i.e. the DRB1*04, DQB1*0302 haplotype).

Association of tumor necrosis factor polymorphism with primary sclerosing cholangitis

BACKGROUND/AIMS

Primary sclerosing cholangitis is associated with the HLA haplotypes A1-B8-DRB3*0101-DRB1*0301-DQA1*0501-DQB1*0201 and DRB3*0101-DRB1*1301-DQA1*0103-DQB1* 0603. However, the interpretation of these genetic associations is controversial. One explanation may be that HLA-encoded susceptibility is due to other genes carried on these haplotypes such as the HLA class III tumor necrosis factor genes. The aim of the study was to investigate tumor necrosis factor genetics in a large series of well-defined patients.

METHODS

One hundred and ten HLA genotyped patients and 126 control subjects were studied by polymerase chain reaction genotyping for 3 different tumor necrosis factor gene polymorphisms: -308, -238 and an Ncol restriction fragment length polymorphism in the lymphotoxin alpha gene.

RESULTS

Overall, 58% of patients had the TNF2 allele, compared with 29% of controls, p(c) = 0.0001. No association was found with either of the other tumor necrosis factor polymorphisms examined. TNF2 was significantly increased in the presence of B8 and DRB3*0101 only, and was independent of DRB1*0301 (p(c)<0.04). The associations with B8 and TNF2 were stronger than the associations with any of the HLA class II alleles examined.

CONCLUSION

HLA-encoded genetic susceptibility to primary sclerosing cholangitis may be determined by polymorphism within the HLA class III region, in particular with the TNF2 allele.

The impact of delaying gastric emptying by either meal substrate or drug on the [13C]-urea breath test

OBJECTIVE

Optimal [13C]-urea breath test (UBT) conditions for diagnosis of Helicobacter pylori infection are still being fine-tuned. In the present study we investigated the impact of delaying gastric emptying by different meal substrates or L-DOPA, a drug known to induce gastric stasis, on the performance of the [13C]-UBT.

METHODS

A total of 115 patients participated in the study. On two consecutive days, participants ingested [13C]-urea (100 mg) 10 min after either 270 ml of a mixed formula meal (1 Kcal/ml) or an equivalent amount of tap water. In 11 participants two additional tests were performed with or without oral 500 mg L-DOPA given 30 min before [13C]-urea load. The 13C/12C ratio in a basal breath sample was compared with ratios in samples collected 30 and 60 min after [13C]-urea. Histological assessment of H. pylori presence in antral biopsy served as reference standard.

RESULTS

Formula UBT showed excellent specificity (100% at 30 and 60 min) and good sensitivity (97% at both time intervals), whereas water UBT had the same specificity but slightly lower sensitivity (94% at 30 min and 73% at 60 min). In formula UBT, 13C/12C ratios were higher at 60 min than at 30 min (21.7+/-2 vs 17.7+/-1.8 per thousand respectively, p < 0.01, whereas in water UBT 13C/12C ratios were higher at 30 min than at 60 min (13.9+/-1.5 vs 8.4+/-0.09 per thousand respectively, p < 0.01). Pretreatment with L-DOPA did not modify either the sensitivity or the specificity of the UBT.

CONCLUSIONS

The performance of the [13C]-urea with a formula meal may not be improved by pharmacologically delaying gastric emptying. A short, water-based test may be a sensible approach to worldwide standardization of the [13C]-UBT for H. pylori infection.

Antineutrophil cytoplasmic antibodies in primary sclerosing cholangitis: defined specificities may be associated with distinct clinical features

PURPOSE

The clinical significance of antineutrophil cytoplasmic autoantibodies (ANCA) in primary sclerosing cholangitis has not been established. We investigated whether analysis of the antigenic specificities of ANCA is useful for delineating clinical subsets of the disease.

METHODS

Sixty-nine patients with primary sclerosing cholangitis were studied. The presence of ANCA was analyzed by indirect immunofluorescence. Antibodies directed against specific antigens--proteinase 3, myeloperoxidase, elastase, bactericidal/permeability-increasing protein, cathepsin G, and lactoferrin--were identified by enzyme-linked immunosorbent assay.

RESULTS

ANCA were detected by indirect immunofluorescence in 46 (67%) patients. In antigen-specific enzyme-linked immunosorbent assays, 37 (55%) of the 69 patients had antibodies to one or more antigens: 32 (46%) had antibodies to bactericidal/permeability-increasing protein, 16 (23%) had antibodies to cathepsin G, and 15 (22%) had antibodies to lactoferrin. Only 3 patients had antibodies to proteinase 3. Antibodies to myeloperoxidase or elastase were not detected. Twenty (29%) patients had antibodies to different antigens simultaneously. ANCA as detected by indirect immunofluorescence were not significantly associated with the presence of cirrhosis nor with the coexistence of inflammatory bowel disease. However, antibodies to bactericidal/permeability-increasing protein and cathepsin G were both associated with the presence of cirrhosis, and antibodies to lactoferrin were more frequently detected in patients with primary sclerosing cholangitis in conjunction with ulcerative colitis than in those without inflammatory bowel disease.

CONCLUSION

Defined specificities of ANCA in primary sclerosing cholangitis may be related to particular clinical features of the disease.

Human leukocyte antigen-C genes and susceptibility to primary sclerosing cholangitis

Genetic susceptibility to primary sclerosing cholangitis (PSC) is associated with the extended HLA A1-B8-DR3 haplotype and also with the DRB3*0101-DRB1*0301-DQA1*0103-DQB1*0603 haplotype. However, very few studies have considered the role of HLA C which lies between HLA A and B, is highly polymorphic, and encodes proteins which play an important role in immunoregulation and in disease susceptibility. Traditional assignment of HLA Cw antigens by serology is both inaccurate and unreliable, with a high error rate. The aim of this study was to characterize the distribution of HLA C alleles in a large group of patients with primary sclerosing cholangitis by using a recently developed polymerase chain reaction-based genotyping technique. Ninety-three white adult patients of northern European origin with well characterized PSC and 100 geographically and racially matched controls were studied. HLA C and HLA DRB1 alleles were assigned by polymerase chain reaction-based genotyping, HLA A and B antigens by standard microlymphocytotoxicity test and extended haplotypes were constructed according to known patterns of linkage disequilibrium. The Cw*07 gene was found in 67.7% of patients versus 54% of controls (P = .051, OR = 1.79). This increase was a result of inheritance of the Cw*0701 allele which was found in 51.6% of patients compared with 34% of controls (P = .013, OR = 2.07). There were no significant differences in the frequencies of any of the other Cw alleles including the Cw*07 group: Cw*0702, Cw*0703, and Cw*0704. HLA-encoded genetic susceptibility to PSC is associated with the HLA Cw*0701 allele, but the association is weak and may simply reflect linkage disequilibrium with the HLA B8-DR3 haplotype. These findings indicate that the telomeric limit of HLA-encoded susceptibility to primary sclerosing cholangitis lies close to the HLA C locus.