Clinical significance of HLA DRB103-DRB104 in type 1 autoimmune hepatitis.

BACKGROUND: HLA DRB1*03-DRB1*04 combines both susceptibility factors for type-1 autoimmune hepatitis. AIMS: Determine whether this phenotype is a risk factor for autoimmune hepatitis in white North American patients, assess its associations with clinical features and treatment outcome, and determine whether alleles within this phenotype affect prognosis. METHODS: One hundred and ninety-eight patients with type 1 autoimmune hepatitis and 102 normal adults were evaluated. HLA typing was performed by DNA-based techniques. RESULTS: Twenty-eight patients had HLA DRB1*03-DRB1*04, and the frequency was higher than in normal subjects (14% vs 4%, OR 4.0%, 95% CI 1.4-11.8, P = 0.01). Patients with DRB1*03-DRB1*04 relapsed less frequently than patients with DRB1*03 (1.3 +/- 0.3 vs 2.1 +/- 0.2, P = 0.04), but they otherwise had outcomes similar to patients with other phenotypes. Patients with DRB1*03-DRB1*04 who had 3-4 alleles encoding lysine at position DRbeta71 within the class II molecule of the major histocompatibility complex developed cirrhosis more commonly (75% vs 9%, P = 0.05) and had a higher frequency of hepatic-related death or liver transplantation (40% vs 0%, P = 0.04) than patients with fewer alleles. CONCLUSIONS: HLA DRB1*03-DRB1*04 is a risk factor for type-1 autoimmune hepatitis, and its impact on outcome relates to the diversity of DRB1*04 alleles that encode a critical motif.     

Evolution of hepatitis C virus infection under host factor influence in an ethnically complex population.

BACKGROUND: The ethnic influence makes it difficult to reach a consensual definition of host-dependent genetic factors controlling the hepatitis C virus (HCV) disease course. Aims: To investigate, in an ethnically complex Brazilian population, whether human leucocyte antigen (HLA) molecules are associated with susceptibility to HCV infection, self-limiting viral clearance and predisposition to chronic disease. METHODS: One hundred and four HCV-antibody-positive patients (stratified into groups with spontaneous viral clearance and chronic HCV infection) and 166 healthy controls were submitted to HLA genotyping. RESULTS: Two strong associations were observed between the susceptibility to HCV infection and DRB3 [odds ratio (OR), 4.03; 95% confidence interval (CI), 2.40-6.77; P(c)=0.0000041] and DQB1*02 (OR, 1.72; 95% CI, 1.05-2.84; P=0.041), and between the spontaneous viral clearance and DRB1*01 (OR, 4.59; 95% CI, 1.70-12.41; P=0.003) and DQB1*03 (OR, 2.83; 95% CI, 1.14-7.02; P=0.029). No evidence was observed regarding the epidemiology or viral genotype influence on the disease course. CONCLUSION: We could confirm with a highly admixed population the association of viral clearance with two allele groups (DRB1*01 and DQB1*03) previously reported in homogeneous populations. The identification of DRB1*01 and DQB1*03 involved with self-limiting hepatitis in different ethnic groups is a very important finding that will contribute to the current knowledge about HCV-host interaction and the development of therapeutic vaccines.     

HLA polymorphisms and cervical human Papillomavirus infection in a cohort of Montreal University students

BACKGROUND: Only a minority of women with human papillomavirus (HPV) infection eventually develop cervical cancer, which suggests that host immune mechanisms play a role in the disease. HLA polymorphisms have been linked to the risk of cervical cancer, but very little is known about the role that they play in the acquisition and persistence of HPV infection. METHODS: A cohort study of cervical HPV infections was used to examine the role that 5 HLA alleles (B*07, DQB1*03, DQB1*0602, DRB1*13, and DRB1*1501) play in determining the risk of HPV positivity and persistence in 524 female university students in Montreal. HPV positivity was determined by use of the MY09/11 polymerase-chain-reaction protocol. HLA alleles from purified DNA from cervical specimens were typed by use of a polymerase-chain-reaction technique using sequence-specific primers. RESULTS: HLA DRB1*13 was associated with cumulative risk of HPV infections (odds ratio [OR], 1.7 [95% confidence interval {CI}, 1.0-2.8]), for oncogenic HPV (OR, 1.6 [95% CI, 0.9-2.8]), and for HPV-16 (OR, 2.0 [95% CI, 0.9-4.4]). DQB1*03 was consistently associated with a lower cumulative risk of HPV infections, but this association was not statistically significant. None of the alleles affected the risk of HPV persistence. CONCLUSIONS: The results of this study support the hypothesis that certain HLA class II polymorphisms mediate genetic susceptibility to the acquisition of HPV infection.     

Distribution of HLA-DRβ1 alleles among well-characterized rheumatoid arthritis patients from Western India

An association between human leukocyte antigen-DRβ1*04 and rheumatoid arthritis (RA) has been known for more than 25 years. It has been observed in many different populations, and it accounts for approximately one-third of the genetic component of RA susceptibility. Our aim was to study the distribution of HLA-DRβ1 alleles in well-characterized RA patients from Western India. Polymerase chain reaction-based sequence-specific oligonucleotide probing (PCR-SSOP) technique was used to identify HLA-DRβ1 alleles among 80 clinically well-defined patients and 90 normal controls from same ethnicity. A significant increase in the frequency of DRβ1*04 was observed among RA patients (PF% 30 vs. 7.7, OR 4.959, p value 0.00018), whereas DRβ1*03 and *14 were significantly decreased among patients when compared with controls (DRβ1*03, PF% 8.75 vs. 26.6, OR 0.2637, p value 0.00253; DRβ1*14, PF% 17.5 vs. 30.0, OR 0.4949, p value 0.05722). Our results suggest that DRβ1*04 was strongly associated with well-characterized RA patients from Western India, whereas DRβ1*03 and *14 may be protective alleles for RA. The identification of susceptible allele in patients with RA may help physician to make early decisions regarding initiation of early intensive therapy with disease modifying anti-rheumatic drugs and biological agents to decrease disability in RA patients.     

HLA-DRB4 as a genetic risk factor for Churg-Strauss syndrome

OBJECTIVE: To explore the association between HLA alleles and Churg-Strauss syndrome (CSS), and to investigate the potential influence of HLA alleles on the clinical spectrum of the disease. METHODS: Low-resolution genotyping of HLA-A, HLA-B, and HLA-DR loci and genotyping of TNFA -238A/G and TNFA -308A/G single-nucleotide polymorphisms were performed in 48 consecutive CSS patients and 350 healthy controls. RESULTS: The frequency of the HLA-DRB1*07 allele was higher in the CSS patients than in controls (27.1% versus 13.3%; chi(2) = 12.64, P = 0.0003, corrected P [P(corr)] = 0.0042, odds ratio [OR] 2.42, 95% confidence interval [95% CI] 1.47-3.99). The HLA-DRB4 gene, present in subjects carrying either HLA-DRB1*04, HLA-DRB1*07, or HLA-DRB1*09 alleles, was also far more frequent in patients than in controls (38.5% versus 20.1%; chi(2) = 16.46, P = 0.000058, P(corr) = 0.000232, OR 2.49, 95% CI 1.58-3.09). Conversely, the frequency of the HLA-DRB3 gene was lower in patients than in controls (35.4% versus 50.4%; chi(2) = 7.62, P = 0.0057, P(corr) = 0.0228, OR 0.54, 95% CI 0.35-0.84). CSS has 2 major clinical subsets, antineutrophil cytoplasmic antibody (ANCA)-positive, with features of small-vessel vasculitis, and ANCA-negative, in which organ damage is mainly mediated by tissue eosinophilic infiltration; analysis of HLA-DRB4 in patients categorized by different numbers of vasculitic manifestations (purpura, alveolar hemorrhage, mononeuritis multiplex, rapidly progressive glomerulonephritis, and constitutional symptoms) showed that its frequency strongly correlated with the number of vasculitis symptoms (P for trend = 0.001). CONCLUSION: These findings indicate that HLA-DRB4 is a genetic risk factor for the development of CSS and increases the likelihood of development of vasculitic manifestations of the disease.     

A comparative review of HLA associations with hepatitis B and C viral infections across global populations

Hepatitis B (HBV) and hepatitis C (HCV) viral infection or co-infection leads to risk of development of chronic infection, cirrhosis and hepatocellular carcinoma (HCC). Immigration and globalization have added to the challenges of public health concerns regarding chronic HBV and HCV infections worldwide. The aim of this study is to review existing global literature across ethnic populations on HBV and HCV related human leukocyte antigen (HLA) associations in relation to susceptibility, viral persistence and treatment. Extensive literature search was conducted to explore the HLA associations in HBV and HCV infections reported across global populations over the past decade to understand the knowledge status, weaknesses and strengths of this information in different ethnic populations. HLA DR13 is consistently associated with HBV clearance globally. HLADRB1*11/*12 alleles and DQB1*0301 are associated with HBV persistence but with HCV clearance worldwide. Consistent association of DRB1*03 and *07 is observed with HCV susceptibility and non-responsiveness to HBV vaccination across the population. HLA DR13 is protective for vertical HBV and HCV transmission in Chinese and Italian neonates, but different alleles are associated with their susceptibility in these populations. HLA class Ⅰmolecule interactions with Killer cell immunoglobulin like receptors (KIR) of natural killer (NK) cells modulate HCV infection outcome via regulating immune regulatory cells and molecules. HLA associations with HBV vaccination, interferon therapy in HBV and HCV, and with extra hepatic manifestations of viral hepatitis are also discussed. Systematic studies in compliance with global regulatory standards are required to identify the HLA specific viral epitope, stage specific T cell populations interacting with different HLA alleles during disease progression and viral clearance of chronic HBV or HCV infections among different ethnic populations. These studies would facilitate stage specific therapeutic strategies for clearance of HBV and HCV infections or co-infections across global populations and aid in identification of HBV-HCV combined vaccine. HLA associations of chronic HBV or HCV development with confounding host factors including alcohol, drug abuse, insulin resistance, age and gender are lacking and warrant detailed investigation across global populations.     

Genetic heterogeneity in susceptibility to autoimmune hepatitis types 1 and 2

OBJECTIVE: Susceptibility to autoimmune hepatitis (AIH) type 1 has been associated with DRB1*03, DRB1*04, and DRB3 alleles in European and North-American whites, with DRB1*04 in Japan, and with DRB1*04 and DRB1*13 in Latin America. Very few studies have been performed on AIH type 2. The aim of the present study was to evaluate the association of AIH types 1 and 2 with HLA-DR and DQ loci. METHODS: We performed HLA-DRB and -DQB1 typing by polymerase chain reaction amplification with sequence-specific primers (PCR-SSP) in 139 AIH patients. Most had AIH type 1 associated with circulating anti-smooth muscle antibody with F-actin specificity or antinuclear antibody. Twenty-eight patients presented AIH type 2 with anti-liver/kidney microsome type 1 or anti-liver cytosol type 1 antibodies. RESULTS: We observed a significant increase of DRB1*13 (70% vs 26% of controls, p < 0.00001) and DRB3 (93% vs 69% of controls, p < 0.00001) in AIH type 1 patients. Analysis of patients without DRB1*13 disclosed a secondary association with DRB1*03 (70% vs 30% of controls, p = 0.0001) and either the DRB1*13 or the DRB1*03 alleles were present in the majority of these patients (91% vs 48% of controls, p = 0.001). Comparison of DRB1*13- and DRB1*03-positive subjects revealed that the former alleles conferred susceptibility to younger patients with AIH type 1. DQB1 typing showed a significant increase in DQB1*06 (68% vs 41% of controls, p = 0.00007) in strong linkage disequilibrium with DRB1*13, and a decrease in DQB1*0301 (8% vs 47% of controls, p(c) = 0.0003). On the other hand, HLA typing of patients with AIH type 2 disclosed a significant increase in the DRB1*07 (68% vs 20% of controls, p(c) < 0.00014), DRB4 (79% vs 43% of controls, p(c) = 0.004), and DQB1*02 (86% vs 42%, p = 0.00002) alleles. After exclusion of DRB1*07, a secondary association with HLA-DRB1*03 was further observed in these patients (78% vs 30%, p = 0.007) and most of them had either DRB1*07 or DRB1*03 (93% vs 44% of controls, p(c) < 0.0001). CONCLUSIONS: Our data indicate that predisposition to AIH types 1 and 2 is associated, respectively, with the DRB1*13 or DRB1*03 and DRB1*07 or DRB1*03 alleles, and suggest that protection against type 1 disease may be conferred by DQB1*0301. In addition, the cluster of DRB1*13 in children with AIH type 1 also supports the concept that different HLA alleles might influence the onset of the disease.     

lnfluence of HLA-DRB1 alleles and HBV genotypes on interferon-α therapy for chronic hepatitis B

AIM: To investigate the influence of HLA-DRB(1) alleles and HBV genotypes on interferon-alpha therapy for chronic hepatitis B. METHODS: HLA-DRB1*03, *07, *09, *12, *15 alleles were determined using polymerase chain reaction/sequence specific primer (PCR/SSP) technique in 126 patients with chronic hepatitis B and 76 normal control subjects in Shandong Province, and HBV genotypes were determined by nested-PCR analysis using type-specific primers in 126 patients. RESULTS: The positivity of HLA-DRB1*07 allele in chronic hepatitis B group was significantly higher than that in normal control group (chi(2) = 6.33, P<0.025, RR = 2.37). Among the 126 patients, genotype B was found in 38 (30.2%), genotype C in 69 (54.8%), and mixed genotype (B+C) in 19 (15.0%), genotypes D-F were not found. Among the 46 DRB1*07(+) patients, 7 were responders and 39 were non-responders among them (chi(2) = 6.71, P<0.05). The positivity of HLA-DRB1*07 and prevalence of HBV genotype C were significantly higher in non-responders than in responders. CONCLUSION: High positivities of HLA-DRB1 *07 allele and HBV genotype C are closely associated with the lower response to interferon-alpha therapy for chronic hepatitis B.     

Relationship of human leukocyte antigen class Ⅱ genes with the susceptibility to hepatitis B virus infection and the response to interferon in HBV-infected patients

AIM: To study the relationship of human leukocyte antigen (HLA)-DRB1 and -DQB1 alleles with the genetic susceptibility to HBV infection and the response to interferon (IFN) in HBV-infected patients.METHODS: Low-resolution DNA typing kit was used to determine HLA-DR-1 and -DQB1 genes in 72 patients with chronic hepatitis B (CHB) and HLA-DRB1 in 200 healthy people ready to donate their bone marrow in Shanghai.Among CHB patients, 35 were treated with IFNα-1b for 24 wk.RESULTS: The frequencies of HLA-DRB1*06, DRB1*08and DRB1*16 alleles in 72 patients were higher than in 200 healthy people (2.08% vs0%, OR = 3.837, P= 0.018;11.11% vs5.50%, OR = 2.148, P= 0.034; and 6.94% vs 3.00%, OR = 0.625, P = 0.049, respectively); whereas that of DRB1*07 allele was lower (2.78% vs 7.75%,OR = 0.340, P = 0.046). The frequency of HLA-DRB1* 14allele was higher in 11 responders to IFN compared with 24 non-responders (18.18% vs2.08%, OR = 10.444,P = 0.031), whereas that of DQB1*07 allele was inverse (9.09% vs 37.50%, OR = 0.167, P= 0.021).CONCLUSION: The polymorphism of HLA class Ⅱ may influence the susceptibility to HBV infection and the response to IFN in studied CHB patients. Compared with other HLA-DRB1 alleles, HLA-DRB1*06, DRB1*08, and DRB1*16 may be associated with chronicity of HBV infection, HLA-DRB1*07 with protection against HBV infection, and HLA-DRB1*14 allele may be associated with a high rate of the response of CHB patients to IFN treatment.Compared with other HLA-DQB1 alleles, HLA-DQB1*07 may be associated with low response rate to IFN.     

Tnfluence of HLA-DRB1 alleles and HBV genotypes on interferon-α therapy for chronic hepatitis B

AIM: To investigate the influence of HLA-DRB1 alleles and HBV genotypes on interferon-α therapy for chronic hepatitis B.METHODS: HLA-DRB1*03, *07, *09, *12, *15 alleles were determined using polymerase chain reaction/sequence specific primer (PCR/SSP) technique in 126 patients with chronic hepatitis B and 76 normal control subjects in Shandong Province, and HBV genotypes were determined by nested-PCR analysis using type-specific primers in 126 patients.RESULTS: The positivity of HLA-DRB1*07 allele in chronic hepatitis B group was significantly higher than that in normal control group (x2 = 6.33, P<0.025, RR = 2.37). Among the 126 patients, genotype B was found in 38 (30.2%), genotype C in 69 (54.8%), and mixed genotype (B+C) in 19 (15.0%),genotypes D-F were not found. Among the 46 DRB1*07(+)patients, 7 were responders and 39 were non-responders among them (x2 = 6.71, P<0.05). The positivity of HLADRB1*07 and prevalence of HBV genotype C were significantly higher in non-responders than in responders.CONCLUSION: High positivities of HLA-DRB1 *07 allele and HBV genotype C are closely associated with the lower response to interferon-α therapy for chronic hepatitis B.     

Tnfluence of HLA-DRB1 alleles and HBV genotypes on interferon-α therapy for chronic hepatitis B

AIM: To investigate the influence of HLA-DRB1 alleles and HBV genotypes on interferon-α therapy for chronic hepatitis B.METHODS: HLA-DRB1*03, *07, *09, *12, *15 alleles were determined using polymerase chain reaction/sequence specific primer (PCR/SSP) technique in 126 patients with chronic hepatitis B and 76 normal control subjects in Shandong Province, and HBV genotypes were determined by nested-PCR analysis using type-specific primers in 126 patients.RESULTS: The positivity of HLA-DRB1*07 allele in chronic hepatitis B group was significantly higher than that in normal control group (x2 = 6.33, P<0.025, RR = 2.37). Among the 126 patients, genotype B was found in 38 (30.2%), genotype C in 69 (54.8%), and mixed genotype (B+C) in 19 (15.0%),genotypes D-F were not found. Among the 46 DRB1*07(+)patients, 7 were responders and 39 were non-responders among them (x2 = 6.71, P<0.05). The positivity of HLADRB1*07 and prevalence of HBV genotype C were significantly higher in non-responders than in responders.CONCLUSION: High positivities of HLA-DRB1 *07 allele and HBV genotype C are closely associated with the lower response to interferon-α therapy for chronic hepatitis B.     

Association between the HLA-DRB1 gene and clinical features of systemic sclerosis in Korea

OBJECTIVE: To determine whether HLA-DR alleles are associated with the development and clinical features of systemic sclerosis (SSc) in Koreans. METHODS: Seventy-nine patients (74 women and five men; 45 diffuse types and 34 limited types; mean age at diagnosis 43.9 years) fulfilling the American College of Rheumatology (ACR) classification criteria for SSc were enrolled. The controls were 144 healthy, disease-free Koreans. HLA-DRB1 genotypes were assessed by the polymerase chain reaction-sequence specific oligonucleotide probe (PCR-SSOP) method. RESULTS: The HLA-DRB1*15 allele was increased in anti-topoisomerase I autoantibody (anti-topo I)-positive SSc patients [p = 0.003, p corrected (p(corr)) = 0.039, odds ratio (OR) = 3.43, 95% confidence interval (CI) 1.45-8.13] compared with controls. The DRB1*11 allele was also observed more frequently in anti-topo I-positive SSc than in controls (13.3% vs. 4.2%) but not statistically significant (p = 0.053, p(corr) = 0.689). In patients with SSc, the DRB1*04 allele was associated with subcutaneous calcinosis (p = 0.048, OR = 4.56, 95% CI 1.07-19.37). Patients with overlap syndrome showed a negative association with the DRB1*04 allele (p = 0.036, OR = 0.26, 95% CI 0.08-0.91). CONCLUSION: The HLA-DRB1*15 allele was associated with the development of anti-topo I-positive SSc in Koreans. In addition, the DRB1*04 allele was associated with certain clinical features in SSc patients.     

Noninherited maternal antigens do not increase the susceptibility for familial rheumatoid arthritis. European Consortium on Rheumatoid Arthritis Families (ECRAF)

OBJECTIVE: It has been proposed that noninherited maternal HLA-DR antigens (NIMA) might play a role in the susceptibility for rheumatoid arthritis (RA). This hypothesis has not been thoroughly tested in patients with familial RA, in whom genetic factors, either inherited or not, might have stronger influence than in patients with sporadic RA. We investigated the NIMA hypothesis in a large cohort of European patients with familial RA. METHODS: The distribution of NIMA, noninherited paternal antigens (NIPA), and inherited HLA-DR antigens was assessed in patients with familial RA from all family sets collected from 1996 onwards by the ECRAF. HLA-DRB1 oligotyping from patients and all available nonaffected siblings and parents was carried out. Familial RA was defined by the presence of at least 2 affected first-degree relatives in the same family. The frequencies of HLA-DR NIMA and NIPA were compared using odds ratios after stratification for HLA-DR*04, *0401, and/or *0404 and shared epitope (SE) status. NIMA/NIPA that coincided with inherited parental HLA-DR antigens were considered redundant and were excluded from analysis. RESULTS: NIMA and NIPA could be analyzed in 165 RA patients with familial RA and 84 nonaffected siblings. Patients were predominantly female, rheumatoid factor positive, and had erosive disease (81, 75, and 84%, respectively). Possession of HLA-DR*04 and *0401/*0404 alleles tended be more frequent in patients than in nonaffected siblings but this did not reach statistical significance. SE possession was similar in patients and healthy siblings, although the former had a double dose SE more often (37.6 vs 17.8%; p = 0.002). Transmission of SE encoding alleles from parents to offspring was skewed only in patients [OR (95% CI) 3.56 (2.55-4.95) vs 1.16 (0.75-1.79) in nonaffected siblings]. Using the NIPA as control, the frequencies of HLA-DRB1*04, *0401/*0404, and SE positive NIMA were not increased in patients lacking these susceptibility alleles. The frequencies of NIMA encoding susceptibility alleles in DR*04 and *0401/*0404 negative patients were lower than in nonaffected siblings. CONCLUSION: Our results corroborate the association between RA and inherited SE alleles and do not support a role for noninherited HLA-DR maternal antigens in the susceptibility for familial RA.     

Racial differences in HLA class II associations with hepatitis C virus outcomes

A broad, vigorous CD4 T cell response, mediated by class II human leukocyte antigens (HLAs), favors hepatitis C virus (HCV) clearance. HLA-DQB1*0301 has been associated with viral clearance in an ethnically homogeneous cohort. To validate this association and to identify other class II associations in an ethnically varied cohort, molecular class II HLA typing was performed on 200 HCV clearance and 374 matched persistently infected subjects. HLA-DQB1*0301 was weakly associated with viral clearance in combined ethnic groups (odds ratio [OR], 0.72; 95% confidence interval [CI], 0.53-0.97) but was stronger in black subjects. In white subjects, viral clearance was associated with DRB1*0101 (OR, 0.32; 95% CI, 0.17-0.60) and its DQB1*0501 haplotype, whereas viral persistence was associated with DRB1*0301 (OR, 2.36; 95% CI, 1.23-4.52) and its DQB1*0201 haplotype. These results support a role for class II alleles in the immune response to HCV and underscore the importance of studying genetic associations in an ethnically diverse cohort.     

Predominance of HLA-DRB1*0405 in Korean patients with rheumatoid arthritis.

OBJECTIVE--To identify the association of HLA-DR4 subtypes with rheumatoid arthritis (RA) in Koreans. METHODS--Ninety five patients with RA and 118 normal control subjects were examined for HLA-DR antigens by serology. Subtypes of HLA-DR4 were determined by allele specific oligonucleotide typing. RESULTS--The phenotype frequency of HLA-DR4 in RA patients was significantly greater than that in controls (60.0% versus 31.4%, odds ratio (OR) 3.28, 95% confidence interval (CI) 1.79 to 6.02 (p < 0.001)), but HLA-DR6 was decreased in RA patients (15.8% versus 32.2%, OR 0.39, 95% CI 0.19 to 0.81 (p < 0.001)). When DR4 was excluded from analysis of patients and controls, the allele frequency of DR1 was significantly increased in the patients compared with controls (11.3% versus 4.5%, OR 2.73, 95% CI 0.87 to 5.95 (p < 0.001)). Forty two of 57 DR4 positive patients (73.7%) possessed DRB1*0405, which was strongly associated with RA (44.2% of patients, versus 11.9% of controls: OR 5.88, 95% CI 2.81 to 12.47 (p < 0.001)). DRB1*0403 was not found in the patients, but was present in 8.5% of controls. Examining the third hyper-variable region at position 70-74 in the DRB1*04 chain by oligotyping, we found that 52 of 57 DR4 positive patients (91.2%) carried one of the conserved amino acid sequences QRRAA or QKRAA, known to be the epitope conferring predisposition to RA. CONCLUSION--This study confirms that RA is strongly associated with DR4, especially with DRB1*0405, and that the presence of the inferred QRRAA sequence may be important in susceptibility to RA in Koreans.     

Methylenetetrahydrofolate reductase 677 T allele protects against persistent HBV infection in West Africa

BACKGROUND/AIMS: Homocysteine metabolism is linked to DNA methylation, a mechanism potentially involved in the course of hepatitis B virus (HBV) infection. We evaluated the association of determinants of homocysteine metabolism with the outcome of HBV infection. METHODS: Four hundred and fifty-five healthy adults from Togo and Benin were tested for HBV serologic markers, HLA DR alleles, folate, vitamin B12, methylenetetrahydrofolate reductase (MTHFR) 677 C-->T, 1298 A-->C and methionine synthase 2756 A-->G polymorphisms. RESULTS: Seventy-eight percent of the study population was anti-HBc positive. Among them, 202 (56.9%) were anti-HBs positive and 58 (16.3%) were HBsAg positive. After stepwise logistic regression, the MTHFR 677 T allele was independently associated with persistence of detectable anti-HBs antibodies (OR: 2.47; 95% CI: 1.29-4.71; p=0.006). The mean HBV DNA level was significantly lower in HBsAg positive subjects carrying the 677 T allele than in those with the 677 CC genotype (1000+/-1406 vs. 2,400,000+/-214,000 copies/ml, p=0.005). Beninese origin and HLA-DRB1*09 allele were the other determinants independently associated with favorable outcome of HBV infection. CONCLUSIONS: The methylenetetrahydrofolate reductase 677 T allele seems to protect against chronic HBV infection in young African adults.     

The association of DRB1*04 share epitope alleles and tumor necrosis factor-alpha gene polymorphism (−863) with susceptibility to rheumatoid arthritis in Thai

Rheumatoid arthritis (RA) in Thai population is significantly associated with HLA-DR4 shared epitope (SE) alleles, particularly with DRB1*0405 (P = 0.00004, OR = 3.84, 95% CI = 1.93, 7.7). In addition, tumor necrosis factor-alpha (TNF-alpha) gene −863A alleles were found to be significantly increased in 77 RA patients compared to 162 healthy controls (P = 0.03, OR = 1.73, 95% CI = 1.05, 2.87). Interestingly, TNF-863 AC and SE have a synergistic effect on the susceptibility to RA. The OR for the presence of both risk factors (DR4 SE and −863 AC) was cumulative: 15.4 (95% CI = 3.75, 73.6) while the separate OR of DR4 SE and −863 AC were 3.84 and 2.36, respectively. The TNF was not associated with the clinical manifestation and severity of Thai RA patients. However, a highly significant association was found between RF positivity, one marker for severity, and RA patients with DR4 SE (P = 0.0005, OR = 9.42, 95% CI = 2.26, 45.27).     

HLA variants related to primary sclerosing cholangitis influence rejection after liver transplantation

AIM:To investigate influence of human leukocyte antigen(HLA)and killer immunoglobuline-like receptor(KIR)genotypes on risks of acute rejection(AR)after liver transplantation(LTX).METHODS:In this retrospective study we included143 adult donor-recipient pairs with a minimum of 6mo follow-up after LTX for whom DNA was available from both donor and recipients.Clinical data,all early complications including episodes and severity of AR and graft/patient survival were registered.The diagnosis of AR was based on clinical,biochemical and histological criteria.All suspected episodes of AR were biopsy confirmed.Key classical HLA loci(HLA-A,HLA-B,HLA-C and HLA-DRB1)were genotyped using Sanger sequencing.16 KIR genes were genotyped using a novel real time PCR approach which allows for determination of the diploid copy number of each KIR gene.Immunohistochemical staining for T(CD3),B(CD20)and natural killer(NK)cells(CD56 and CD57)were performed on liver biopsies from 3 different patient groups[primary sclerosing cholangitis(PSC),primary biliary cirrhosis and non-autoimmune liver disease],10 in each group,with similar grade of AR.RESULTS:Fourty-four(31%)patients were transplanted on the basis of PSC,40%of them had AR vs 24%in the non-PSC group(P=0.04).No significant impact of donor-recipient matching for HLA and KIR genotypes was detected.In the overall recipient population an increased risk of AR was detected for HLA-B*08(P=0.002,OR=2.5;95%CI:1.4-4.6),HLA-C*07(P=0.001,OR=2.4;95%CI:1.4-4.0)and HLA-DRB1*03(P=0.03,OR=1.9;95%CI:1.0-3.3)and a decreased risk for HLA-DRB1*04(P=0.001,OR=0.2;95%CI:0.1-0.5).For HLA-B*08,HLA-C*07 and DRB1*04 the associations remained evident in a subgroup analysis of non-PSC recipients(P=0.04,P=0.003 and P=0.02,respectively).In PSC recipients corresponding P values were 0.002,0.17 and 0.01 for HLA-B*08,HLA-C*07and DRB1*04,respectively.A dosage effect of AR prevalence according to the PSC associated HLA alleles was also notable in the total recipient population.For HLA-B*08 the frequency of AR was 56%in HLA-B*08homozygous recipients,39%in heterozygous recipients and 21%in recipients lacking HLA-B*08(P=0.02).The same was observed for the HLA-C*07 allele with AR in 57%,27%and 18%in recipients being homozygous,heterozygous and lacking HLA-C*07 respectively(P=0.003).Immunohistochemical analysis showed similar infiltration of T,B and NK cells in biopsies with AR in all three groups.CONCLUSION:We found significant associations between the PSC-associated HLA-B*08,HLA-C*07,HLADRB1*03 and HLA-DRB1*04 alleles and risk of AR in liver transplant recipients.     

HLA-DR4-Ala74β is associated with risk and poor outcome of severe aplastic anemia

 Severe aplastic anemia (SAA) is a heterogeneous hematological disorder with a high mortality. Genetic predisposition has been shown to play a role in a considerable proportion of SAA cases. For instance, the human lymphocyte antigen HLA-DR2 has been repeatedly demonstrated to be over-represented in SAA patients. In this paper, we expand on the evidence for the contribution of HLA polymorphism in the susceptibility to SAA, which was obtained using the "high-resolution" technique of HLA-DRB1 subtyping. The DRB1*1501 allele appeared to be responsible for the predominance of DR2 specificity in SAA patients and was the most significant risk factor for this disease. It was observed in 23/44 (52.3%) patients versus 22/100 (22.0%) donors [odds ratio (OR)=3.9; 95% confidence interval (CI): 1.8–8.3;P=0.0005, corrected P (Pc)<0.05]. In addition, DRB1*04 alleles also displayed non-random distribution in the SAA group. In particular, DRB1*04 variants coding for alanine at position 74 of the DRβ1 chain (HLA-DR4-Ala74β subtype) were detected in all 13 DR4-positive SAA patients but only in 15/24 (62.5%) controls (OR=16.6; 95% CI: 0.9–312.0;P=0.015). Multiple comparison analysis confirmed that the HLA-DR4-Ala74β subtype confers susceptibility to SAA independently from the DRB1*1501 allele. Finally, examination of the clinical records has shown that the HLA-DR4-Ala74β subtype is associated with poor outcome of SAA. Received: 13 September 1999 / Accepted: 7 June 2000     

Association of HLA-DRB1*13 and TNF-alpha gene polymorphisms with clearance of chronic hepatitis B infection and risk of hepatocellular carcinoma in Thai population

Considerable evidence suggests that host genetic factor play an important role in the pathogenesis and clinical outcome of chronic hepatitis B virus (HBV) infection in several ethic groups. Association study was performed included 150 chronic HBV patients, 100 resolved hepatitis B and 150 healthy individuals with similar ethic background. Interestingly, human leucocyte antigen (HLA)-DR13 show a strong association with the clearance of HBV [odds ratio (OR) = 0.04, 95% confidence interval (CI) = 0.00-0.26, corrected P-value (P(c)) = 0.0008] similar to reports from several ethic groups. TNF-alpha promoter polymorphisms (-863, -308 and -238) were also analysed. Only -863 C allele was found to be significantly decreased in chronic HBV patients compared with healthy control (P(c) = 0.03, OR = 0.54, 95% CI = 0.35-0.84 respectively). This -863C allele was not in linkage disequilibrium with HLA-DR13 suggesting that other genetic markers linked with -863C might influence clearance of chronic HBV infection in Thai. When stratified chronic HBV patients into patients without hepatocellular carcinoma (HCC) and with HCC, the -863 A allele was significantly increased in the HCC group compared to healthy control (P(c) = 0.003, OR = 2.61, 95% CI = 1.49-4.60). Haplotype analysis (-863/-308/-238) revealed that the homozygosity of the haplotype (CGG/CGG) was a protective marker for HCC (OR = 0.37, 95% CI = 0.17-0.79, P(c) = 0.02). One can propose that carriers of -863A genotype are associated with increased levels of TNF-alpha in the liver in response to HBV infection and induce hapatocyte damage that may finally lead to HCC development. Additional study is needed to validate these finding and to further explore the genetic pathogenesis of HBV infection.