HLA class II genes in primary sclerosing cholangitis and chronic inflammatory bowel disease: no HLA-DRw52a association in Swedish patients with sclerosing cholangitis

Large-duct cholangiopathies: aetiology, diagnosis and treatment

Cholangiopathies describe a group of conditions affecting the intrahepatic and extrahepatic biliary tree. Impairment to bile flow and chronic cholestasis cause biliary inflammation, which leads to more permanent damage such as destruction of the small bile ducts (ductopaenia) and biliary cirrhosis. Most cholangiopathies are progressive and cause end-stage liver disease unless the physical obstruction to biliary flow can be reversed. This review considers large-duct cholangiopathies, such as primary sclerosing cholangitis, ischaemic cholangiopathy, portal biliopathy, recurrent pyogenic cholangitis and Caroli disease.

[Primary sclerosing cholangitis: diagnosis, prognosis and treatment]

Primary sclerosing cholangitis is a chronic cholestatic disease characterized by inflammation with fibrosis and obliteration of the intra- and extrahepatic bile ducts. This disease is usually associated with ulcerative colitis. The process of chronic cholestasis eventually leads to biliary cirrhosis. The prevalence of primary sclerosing cholangitis is low in southern Europe but is especially high in Scandinavian countries. The etiopathogenesis is unknown but immune disorders, potential toxic agents or intestinal infections, ischemic injury to the bile ducts, and possibly alterations in hepatobiliary transporters are known to play a role. The disease manifests at the age of approximately 40 years, mainly in men with clinical and laboratory features of cholestasis but may also be asymptomatic. There are specific forms in which the small intrahepatic bile ducts are involved, mainly affecting children, as well as overlap syndromes with autoimmune hepatitis. A form characterized by an increase in IgG4 has been described, which is usually associated with autoimmune pancreatitis. The key diagnostic procedure is endoscopic retrograde cholangiography, although magnetic resonance cholangiography is the first diagnostic procedure that should be used since it is equally informative and non-invasive. Liver biopsy is not essential for diagnosis. Primary sclerosing cholangitis is a progressive disease with a probability of transplant-free survival of 18 years in asymptomatic forms and of 8.5 years in symptomatic forms. Cholangiocarcinoma can result from the disease and confers a poor prognosis. There is no specific treatment although ursodeoxycholic acid improves the biochemical alterations of cholestasis. Liver transplantation is the last therapeutic resort with good results in terms of survival although the disease can recur in the transplanted liver.

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.

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.

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.

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.

Management of primary sclerosing cholangitis

Guidelines for clinical practice are intended to indicate preferred approaches to medical problems as established by scientifically valid research. Double blind, placebo-controlled studies are preferable, but reports and expert review articles are also utilized in a thorough review of the literature conducted through the National Library of Medicine's MEDLINE. When only data that will not withstand objective scrutiny are available, a recommendation is identified as a consensus of experts. Guidelines are applicable to all physicians who address the subject, without regard to specialty training or interests, and are intended to indicate the preferable but not necessarily the only acceptable approach to a specific problem. Guidelines are intended to be flexible and must be distinguished from standards of care that are inflexible and rarely violated. Given the wide range of specifics in any health care problem, the physician must always choose the course best suited to the individual patient and the variables in existence at the moment of decision. Guidelines are developed under the auspices of the American College of Gastroenterology and its Practice Parameters Committee and approved by the Board of Trustees. Each has been intensely reviewed and revised by the Committee, other experts in the field, physicians who will use them, and specialists in the science of decision of analysis. The recommendations of each guideline are therefore considered valid at the time of their production based on the data available. New developments in medical research and practice pertinent to each guideline will be reviewed at an established time and indicated at publication to assure continued validity.

A patient with hereditary hemochromatosis, ulcerative colitis, and primary sclerosing cholangitis: genetic aspects

This report describes a family in which the rare combination of hereditary hemochromatosis, ulcerative colitis and primary sclerosing cholangitis was found. Subsequent to the index patient, who had all three diseases, a screening was done in his parents and siblings that included HLA-DR, HLA-DQ and HFE typing, ANCAs, liver tests and sigmoidoscopy with histology. On the basis of HLA and HFE typing, three probable haplotypes could be distinguished. The genetics of inflammatory bowel disease and hereditary hemochromatosis are discussed.

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.

Autoimmune cholangitis within the spectrum of autoimmune liver disease

Autoimmune cholangitis is an idiopathic disorder with mixed hepatocellular and cholestatic findings. Our goal was to characterize the disease prospectively by application of uniform diagnostic criteria. Twenty patients were identified and compared with 242 patients with conventional forms of autoimmune liver disease. Patients with autoimmune cholangitis were distinguished from type 1 autoimmune hepatitis (AIH) by lower serum levels of aspartate transaminase (AST), gamma-globulin, and immunoglobulin G; higher serum levels of alkaline phosphatase; and lower frequencies of autoantibodies. They were distinguished from primary biliary cirrhosis (PBC) by higher serum levels of AST and bilirubin, lower serum concentrations of immunoglobulin M, and greater occurrence of autoantibodies. Their female predominance, lower serum alkaline phosphatase levels, higher frequency of autoantibodies, and absence of inflammatory bowel disease differentiated them from primary sclerosing cholangitis (PSC). Laboratory findings ranged widely and did not characterize individual patients. HLA risk factors were similar to those of type 1 AIH and PBC, and different from those of PSC. Treatment responses to corticosteroids or ursodeoxycholic acid were poor. Composite histological patterns resembled mainly PBC or PSC. We conclude that autoimmune cholangitis diagnosed by prospective analysis cannot be assimilated into a single, conventional, diagnostic category. It may represent variant forms of diverse conditions, a transition stage, or a separate entity with varying manifestations.

HLA-DR and -DQ phenotypes in inflammatory bowel disease: a meta-analysis

BACKGROUND

Susceptibility to inflammatory bowel disease (IBD) is partially genetically determined and the HLA class II genes are candidates for a role in genetic susceptibility to IBD, because their products play a central role in the immune response. Multiple studies have reported associations between HLA-DR or -DQ phenotypes and either ulcerative colitis or Crohn's disease, but much of the data are still controversial.

AIMS

To estimate overall associations between HLA class II phenotypes and IBD, and to establish the relative risk conferred by HLA-DR and -DQ phenotypes by meta-analysis.

METHODS

Medline was searched for publications reporting on the relation between IBD and HLA class II phenotypes. Raw data were extracted by recalculating the number of phenotypes or the number of alleles of the main antigens. Odds ratios and confidence intervals were calculated according to the Mantel-Haenszel method.

RESULTS

DR2, DR9, and DRB1*0103 were positively associated with ulcerative colitis, and a negative association was found for DR4 and ulcerative colitis. For Crohn's disease a positive association was found with DR7, DRB3*0301, and DQ4 and a negative association with DR2 and DR3.

CONCLUSIONS

Both ulcerative colitis and Crohn's disease are associated with specific HLA class II phenotypes. Further analysis of these phenotypes and subgroup analysis may elucidate how these alleles contribute to susceptibility to IBD.

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).

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.

Analysis of MHC class II DP, DQ and DR alleles in Crohn's disease

BACKGROUND

Although inflammation in Crohn's disease is believed to be mediated by activated T cells, genotyping of all MHC class II alleles in white people with this disease has not been reported.

AIMS

To perform a detailed molecular analysis of HLA DPB, DQB, and DRB genes in white patients with Crohn's disease and controls in order to determine if the inheritance of any class II genes confers susceptibility or resistance to this disease.

METHODS

Complete molecular typing of HLA class II DPB, DQB, and DRB alleles was performed in 58 white patients with Crohn's disease and 93 healthy controls using a polymerase chain reaction-sequence specific oligonucleotide based approach.

RESULTS

No significant association with any DPB or DQB alleles was noted in patients with Crohn's disease. Since our previous studies had shown a strong association of an HLA DRB3*0301/DRB1*1302 haplotype with Crohn's disease, we re-examined this association using more stringent genotyping criteria. This haplotype was present in 20.7% of patients and 5.4% of controls (p = 0.0066; relative risk = 4.59).

CONCLUSIONS

The DRB3*0301/DRB1*1302 haplotype is the only significant MHC class II association noted in white people with Crohn's disease and represents the strongest association of any MHC or non-MHC locus with this disease.

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.

Differences in colonic disease activity in patients with ulcerative colitis with and without primary sclerosing cholangitis: a case control study

PURPOSE

A small group of patients with ulcerative colitis (UC) also suffer from primary sclerosing cholangitis (PSC). Genetic and immunologic differences exist between UC patients with and without concomitant PSC. Furthermore, UC patients with PSC are more prone to developing colonic dysplasia/aneuploidy compared with patients with UC only. Because colonic disease activity and treatment with sulfasalazine have been found to be of independent importance for development of colonic carcinoma in UC, this study aims to determine if differences exist concerning colonic disease activity in UC patients with and without PSC.

METHODS

Twenty-nine PSC patients with total colitis were matched to two UC patients with total colitis but without liver disease. Case records and questionnaires were used to gain information on pharmacologic treatment and disease activity.

RESULTS

Observation time was 20 (PSC group) and 23 years (UC only). Number of patients taking prophylactic treatment did not differ between groups. Patients with UC only had received treatment with systemic and local corticosteroids significantly more often than UC patients with PSC (P < 0.05 and P < 0.02). Patients with UC only were hospitalized because of colonic activity significantly more often (P < 0.02). Number of patients undergoing colectomy because of disease activity or number of patients with chronic continuous symptoms did not differ between the two groups.

CONCLUSION

UC in patients with PSC runs a milder course than UC in patients without this complication, although the number of patients taking prophylactic treatment was the same. If lower disease activity reflects differences in pathogenesis of UC in patients with PSC or if it can explain increased risk to develop colonic malignancy in patients with both PSC and UC needs further elucidation.

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.

Ulcerative colitis: a genetic disease?

A number of lines of evidence support the hypothesis that ulcerative colitis is an inherited disorder in a proportion of cases. First, there is a pattern of familial aggregation. Second, there are differences in the prevalence of the disease in different ethnic groups. Finally, the concordance rate in monozygotic twin pairs is higher than that of dizygotic twin pairs, although not as high as the concordance rates observed in Crohn's disease. Genetic models of the inheritance patterns suggest that ulcerative colitis is probably caused by one major gene, although that gene (or genes) remains to be identified. While at least one localization for susceptibility to Crohn's disease now seems certain, efforts to localize and characterize the susceptibility genes involved in the inheritance of ulcerative colitis are still underway. While the genes of the major histocompatibility complex have been imputed as causal in susceptibility to ulcerative colitis, a consensus of proof continues to elude us.

Natural history and prognostic factors in 305 Swedish patients with primary sclerosing cholangitis

BACKGROUND/AIMS--The course of primary sclerosing cholangitis (PSC) is highly variable and unpredictable. This study describes the natural history and outcome of PSC. These data were used to construct a prognostic model for patients with PSC. METHODS--A total of 305 Swedish patients with PSC were studied. The median follow up time was 63 (1-194) months and all patients could be traced for follow up. Some 79 patients died or had a liver transplant. The prognostic significance of clinical, biochemical, and histological findings at the time of diagnosis were evaluated using multivariate analysis. RESULTS--The estimated median survival from time of diagnosis to death or liver transplantation was 12 years. Cholangiocarcinoma was found in 24 (8%) of the patients and 134 (44%) of the patients were asymptomatic at the time of diagnosis. The estimated survival rate was significantly higher in the asymptomatic group (p < 0.001). However, 29 (22%) of the asymptomatic patients became symptomatic during the study period. It was found that age, serum bilirubin concentration, and histological stage at the time of diagnosis were independent predictors of a bad prognosis. These variables were used to construct a prognostic model. CONCLUSIONS--This prognostic model developed from a large homogeneous population of PSC patients should be of value for the timing of transplantation and patient counselling in PSC.

Genetic predispositions for immunological features in chronic liver diseases other than autoimmune hepatitis

BACKGROUND/AIMS

Human leukocyte antigens DR3 and DR4 influence susceptibility for type 1 autoimmune hepatitis and affect its immunological manifestations. We aimed to determine if autoimmune features in patients with chronic liver diseases other than autoimmune hepatitis are associated with these same antigens.

METHODS

One hundred and seventy-eight patients were evaluated. Class II typing was performed by restriction fragment length polymorphism in all patients and 80 normal subjects.

RESULTS

One or more autoantibodies, including antinuclear antibodies (28%), smooth muscle antibodies (8%), thyroid antibodies (18%) and antimitochondrial antibodies (13%), were found in 92 patients (52%). Concurrent clinical diseases of an immunological nature were recognized in 53 patients (30%). Patients with antinuclear antibodies had a higher frequency of the A1-B8-DR3 haplotype than patients without these antibodies (27% versus 12%, p = 0.04) and patients with concurrent immunological diseases had a higher frequency of HLA DR4 than patients without this antigen (51% versus 26%, p = 0.003). Patients with antinuclear antibodies were more commonly DR3 positive than normals (35% versus 16%, p = 0.03) and patients with concurrent immunological diseases were more commonly HLA DR4 positive than normals (51% versus 30%, p = 0.02).

CONCLUSIONS

We conclude that the clinical expression of antinuclear antibodies is associated with the A1-B8-DR3 haplotype and the presence of concurrent immunological diseases is related to the DR4 antigen. These clinical manifestations have a genetic basis that is not disease-specific.

HLA antigens in ulcerative colitis and primary sclerosing cholangitis

The aims of this study were to find out whether the alleles of the HLA class I or II region are associated with susceptibility to ulcerative colitis, and to show whether there is a difference or similarity in HLA associations between primary sclerosing cholangitis and ulcerative colitis. HLA-A, B, C and DR antigens were studied using the standard lymphocyte microcytotoxicity test in 24 Finnish patients with primary sclerosing cholangitis, 77 patients with ulcerative colitis, and 106 controls. HLA-B8 (54%) and DR3 (60%) were associated with primary sclerosing cholangitis. HLA-DR1 (46%) and DR6 (20%) seemed more common in ulcerative colitis than in controls. A positive association with Cw7 was common to both ulcerative colitis (25%) and primary sclerosing cholangitis (33%). Our results indicate that ulcerative colitis is more heterogeneous than primary sclerosing cholangitis in its HLA-DR associations.

HLA DPB polymorphism in primary sclerosing cholangitis and primary biliary cirrhosis

In recent years there has been an increasing interest in the link between susceptibility to autoimmune liver disease and genes of the HLA system, although the role of the DPB1 locus in British patients has only been investigated in autoimmune hepatitis. The aim of the current study was to determine the distribution of DPB1 alleles in a large series of British patients with the two other autoimmune liver diseases, primary biliary cirrhosis and primary sclerosing cholangitis, and compare the allele frequencies obtained with those of a geographically matched control group. Polymerase chain reaction sequence-specific oligonucleotide probing was used to assign 18 DPB1 alleles in 82 patients with primary biliary cirrhosis (PBC), 71 patients with primary sclerosing cholangitis (PSC), and 103 controls. The frequencies of the DPB1 alleles were not significantly different comparing patients and controls. However, two important observations were made. Firstly, in primary sclerosing cholangitis, the previously reported association with the haplotype A1-B8-DR3-DQ2 does not extend to the DPB1 locus, suggesting that the genetic determinants of susceptibility for this disease lie closer to the DRB loci. Secondly, in primary biliary cirrhosis there is evidence that the reported association with DR8-DQB1*0402 includes the DPB1*0301 allele. The weak HLA association reported here is in contrast with recent data from Japan, where susceptibility is strongly linked to a particular amino acid residue encoded by the DPB1*0501 allele. These data clearly demonstrate that the alleles of the DPB1 locus are not associated with susceptibility to or protection from either primary biliary cirrhosis or primary sclerosing cholangitis in British patients.

HLA-DR and HLA-DQ are not markers for rapid disease progression in primary sclerosing cholangitis

BACKGROUND/AIMS

The association between primary sclerosing cholangitis (PSC) and the HLA haplotype A1, B8, DR3, DQ2 is well established. During the last few years, several additional HLA associations have been suggested in PSC. Furthermore, two different HLA-DR specificities have been reported to be markers for rapid disease progression. Our aim was to critically evaluate all of the current and as yet mostly unconfirmed HLA class II issues in PSC.

METHODS

Seventy-five Swedish patients with PSC were HLA-DR and HLA-DQ genotyped.

RESULTS

Of the recently described HLA associations in PSC, the association with the DRB1*1301, DQA1*0103, DQB1*0603 haplotype was decisively confirmed, whereas the DRB1*04 specificity was only slightly under-represented and the frequency of DR2 was neutral. The association with codon 38 of DRB genes was secondary to the DRB3*0101 association. HLA-DR and HLA-DQ alleles were not found to be markers of disease progression.

CONCLUSIONS

The HLA-associated genetic susceptibility to PSC cannot be attributed to specific amino acid positions of the DR beta chains. The highly discrepant results obtained in two previously reported studies and the present investigation indicate that HLA class II alleles are not markers for a more aggressive clinical course in PSC.

Molecularly defined HLA-DR2 alleles in ulcerative colitis and an antineutrophil cytoplasmic antibody-positive subgroup

BACKGROUND/AIMS

Although HLA-DR2 is associated with Japanese ulcerative colitis, data regarding an HLA-DR2 association in other populations are conflicting. A recent study suggests that HLA-DR2 is only associated with antineutrophil cytoplasmic antibody-positive ulcerative colitis. The aim of this study was to determine whether HLA-DR2 or the molecularly defined alleles within the HLA-DR2 group are associated with ulcerative colitis or a perinuclear antineutrophil cytoplasmic antibody-positive subgroup.

METHODS

Unrelated white patients with a history of ulcerative colitis (n = 97) and control subjects matched to patients for Jewish ethnicity and sex (n = 149) were studied. An immunofluorescence assay was used to detect perinuclear antineutrophil cytoplasmic antibodies. A molecular, DNA-based method was used to perform HLA-DR2 typing.

RESULTS

HLA-DRB1*1601 was present in 11 of 149 controls and 1 of 97 patients (P = 0.031, corrected P, not significant; Fisher's Exact Test). There were no other significant differences between ulcerative colitis or ulcerative colitis stratified by perinuclear antineutrophil cytoplasmic antibody status and controls.

CONCLUSIONS

The HLA-DR2 group of alleles is not associated with ulcerative colitis or a perinuclear antineutrophil cytoplasmic antibody-positive subgroup. The unexpected finding of a decreased frequency of HLA-DRB1*1601 in ulcerative colitis should be further investigated.

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.

Novel genetic association between ulcerative colitis and the anti-inflammatory cytokine interleukin-1 receptor antagonist

BACKGROUND/AIMS

Ulcerative colitis and Crohn's disease have well-recognized familial tendencies, but the genetic basis of this clinical observation remains unknown. The cytokine interleukin-1 receptor antagonist is a potent anti-inflammatory protein that can prevent immune-mediated bowel inflammation in animals. We have previously characterized a polymorphism within the gene for this cytokine and others in the genes for the proinflammatory cytokines interleukin 1 alpha, interleukin 1 beta, and tumor necrosis factor alpha. The aim of this study was to determine whether inflammatory bowel disease was associated with particular alleles of these polymorphic cytokine genes.

METHODS

The allelic frequencies of these polymorphic cytokine genes were determined in patients with ulcerative colitis (n = 113), Crohn's disease (n = 78), and healthy controls (n = 261).

RESULTS

Allele 2 of interleukin-1 receptor antagonist was significantly over-represented in the ulcerative colitis patients: 35% versus 24% in controls (P = 0.007). Carriage of at least one copy of this allele gave an odds ratio of 2.0 for ulcerative colitis compared with controls. This association with allele 2 of interleukin 1 receptor antagonist was greatest in patients with total colitis and was not seen in Crohn's disease. There were no associations between UC and any of the other cytokine genes examined.

CONCLUSIONS

This observation provides evidence that interleukin-1 receptor antagonist may have a role in determining the genetic susceptibility to and pathogenesis of ulcerative colitis.

Typing of the HLA-DRB3 gene by temperature gradient gel electrophoresis. Prediction of the resolution of four allelic fragments by computational simulation of DNA melting

Four alleles are currently recognised at the HLA-DRB3 locus (DRB3*0101, DRB3*0201, DRB3*0202 and DRB3*0301). We studied whether 271 bp fragments of the polymorphic second exon, which were prepared using the polymerase chain reaction, could be typed using temperature gradient gel electrophoresis. Thermal stability curves for the allelic DNA molecules were calculated by computer simulation and the results were validated experimentally. The DRB3*0201 and DRB3*0202 derived homoduplexes were predicted to have identical thermal stability. Thus, only three denaturation and relative mobility curves were obtained for the four homoduplex fragments DRB3*0101, DRB3*0201, DRB3*0202 and DRB3*0301. Computational analysis predicted that DRB3*0201 and DRB3*0202 could be distinguished by electrophoresis of artificially generated heteroduplexes. When verified experimentally, the results of the theoretical analyses were confirmed. We conclude, that computational simulation of the melting behaviour of DNA molecules permits the resolution of allelic sequences to be predicted by temperature gradient gel electrophoresis. We also demonstrate that temperature gradient gel electrophoresis is a powerful tool for the assessment of HLA genotypes. It may have wide application in transplantation immunology and in the study of disease associations of allelic variation at the HLA loci.

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

BACKGROUND/AIMS

Primary sclerosing cholangitis (PSC) is an inflammatory disease of the biliary tree associated with an increase in the HLA alleles DR3, DR52a, DR2, Dw2, and a decrease in DR4. However, it is not certain which of these alleles provides the primary associations. Our aim was to establish the primary HLA associations with PSC and to assess the ability of HLA alleles to mark for disease progression.

METHODS

By applying molecular techniques to archival tissue, we have genotyped 83 PSC patients from two populations and 131 controls for the alleles HLA DR2, DR3, DR4, DRw12, DR52a, and Dw2.

RESULTS

HLA DR3, DR52a, DR2, and Dw2 were all significantly increased in PSC, with the relative risk for DR52a and Dw2 being greater than for DR3 and DR2, respectively. HLA DR4 was significantly decreased, but this may be artifactual to the DR3, DR2 increase. HLA DR4 and not DR52a marks for rapid disease progression in both our PSC populations.

CONCLUSIONS

HLA DR52a and Dw2 are the best candidate alleles for providing the known HLA association with PSC. HLA DR4 and not DR52a marks for rapid disease progression in our two PSC populations.

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.