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PubMed1994

Molecular genetic studies of HLA class II alleles in sarcoidosis.

Previous HLA serological studies showed positive associations of the DR52 antigen, the DR52-associated antigens (DR3, DR5 and DR6) and the DR8 antigen with sarcoidosis. To investigate the HLA alleles that may contribute to the genetic susceptibility to sarcoidosis at the DNA level, HLA-DRB1, -DRB3, -DQA1 and DQB1 genotyping using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method was performed in 63 Japanese patients with sarcoidosis. The frequencies of the DR52-associated DRB1 alleles (DRB1*11, DRB1*12 and DRB1*14 except DRB1*1302), DRB1*08, DRB3*0101, DQA1*0501 and DQB1*0301 were significantly increased in patients compared with healthy controls. The significant increase of DRB3*0101, DQA1*0501 and DQB1*0301 could be explained by linkage disequilibrium with the DR52-associated DRB1 alleles. It must be noted that the DR8 haplotype, which does not possess the DRB3 gene, also showed a significant increase in sarcoidosis. These results suggest that the HLA-alleles responsible for the susceptibility to sarcoidosis are located at the HLA-DRB1 locus rather than the HLA-DRB3, -DQA1 and -DQB1 loci. In contrast, DRB1*1302 may confer resistance to the disease.

HLA-DQ Antigens↗
PubMed1991

Soluble HLA-DR molecules in patients with HLA class II versus class I associated disorders.

HLA genes have been identified as key genetic factors contributing to many chronic diseases characterized by autoimmune features. The role of HLA encoded molecules in the pathogenesis of these diseases is unresolved. We have now analysed soluble HLA-DR molecules circulating in the serum of patients with different autoimmune diseases and have defined parameters controlling serum levels. Patients with HLA-DR associated diseases were characterized by elevated serum concentrations of HLA-DR molecules and were clearly distinct from patients with HLA-B27 associated disorders. We did not find evidence for a correlation between disease activity, laboratory abnormalities and elevated serum concentrations of soluble HLA-DR molecules. Studies in normal individuals indicated that soluble HLA-DR molecules are at least partially regulated by the HLA haplotype. Highest serum concentrations were found in individuals carrying the HLA-DR3 or HLA-DR4 haplotype raising the possibility that the phenomenon of HLA-disease association reflects differences in the genetic control of soluble HLA-DR molecules. Interferon-gamma treatment caused an increase in serum concentrations of soluble HLA-DR molecules, whereas a decrease of circulating HLA-DR molecules was associated with an immunosuppressive with cyclosporine A. These data suggest that the patient's immunoresponsiveness represents a second important mechanism controlling circulating HLA-DR molecules.

Arthritis, Psoriatic↗
PubMed2004

Inheritance mode of multiple sclerosis: the effect of HLA class II alleles is stronger than additive.

We previously identified on chromosome 6 an interval of 51 kb as the most likely interval in the HLA region for a disease-susceptibility locus for multiple sclerosis (MS). The interval was located between markers G511525 and D6S1666 and identified by the haplotype sharing statistic (HSS). The study comprised 124 patients with ancestry within the northeastern part of The Netherlands. Haplotype clustering indicated that two different ancestral haplotypes likely include a polymorphism involved in susceptibility to MS. To investigate the dominance characteristics of the MS susceptibility locus in the HLA class II region, we reanalyzed our data, performing genotype association analyses for both marker loci separately and for the two-locus haplotype. The two-locus genotype association analysis showed that in individuals who carry only one of the risk haplotypes the risk for MS is moderately increased (odds ratio (OR) 2.82; 95% confidence interval (CI) 1.50-5.31). However, in individuals carrying two risk haplotypes the risk for MS is highly increased compared with individuals who carry no risk haplotypes (OR 37.00; 95% CI 8.31-164.74). This susceptibility locus for MS seems to follow an intermediate mode of inheritance. Fitting additive, multiplicative and third power risk models to the data, the effect appears to be significantly stronger than additive.

Alleles↗
PubMed2001

HLA class II allele distribution in the Gypsy community of Andalusia, southern Spain.

We have studied the allele distribution of DRB1, DQB1 and DPB1 loci in 80 unrelated Gypsies living in different eastern areas of the Andalusian province of Granada (southern Spain). The frequency distribution of HLA class II alleles and the genetic distance of Andalusian Gypsies from several Caucasian populations indicate a marked similarity - but not total - of the former with the Gypsy population previously studied in Madrid (central Spain), which suggests that both groups migrated together out of India. In terms of genetic distance, both Gypsy groups are more like the Czech Gypsies and the Northern Indian groups than their neighbouring Caucasian non-Gypsy populations. In summary our data support the hypothesis of a common anthropological origin of all three European Gypsy groups, which probably split up after their arrival in Europe.

Alleles↗
PubMed2004

Genetic basis of the latex-fruit syndrome: association with HLA class II alleles in a Spanish population.

BACKGROUND: The latex-fruit syndrome is a well-defined disorder whose genetic background has not been elucidated. OBJECTIVE: To study the genetic basis of the latex-fruit syndrome. METHODS: In a case-control study, we have investigated a carefully selected group of patients allergic to latex, searching for association between latex-fruit allergy and HLA class I and II genes, HLA-DR functional groups, and markers IL4-R1 and FcepsilonRI-betaca . RESULTS: Seventy-eight patients allergic to latex without spina bifida, 33% of them also allergic to fruits, were included in our protocol. Skin prick test results with both a commercial latex extract and purified hevein were significantly greater in patients allergic to latex and fruit than in patients allergic to latex and not fruit. A cutoff point of >7 mm for commercial latex skin prick test diagnosed latex-fruit allergy with a sensitivity of 66.7% (95% CI, 41.0-86.6) and a specificity of 83.3% (95% CI, 68.6-93.0) in our series of patients. No significant differences were found regarding HLA class I, IL4-R1 , or FcepsilonRI-betaca allele distributions. However, comparison of HLA class II allelic frequencies between patients allergic to latex and fruit and patients allergic to latex and not fruit showed significant associations of latex-fruit allergy with DQB1 *0201 (corrected P value, .001; odds ratio, 7.3; 95% CI, 2.6-20.0), as well as with HLA-DR functional group E (corrected P value, .028; odds ratio, 16.0; 95% CI, 1.9-134.1). When comparing allelic distribution among different subgroups of patients allergic to latex, additional significant associations of latex-fruit allergy with DRB1 *0301 and *0901, and of latex and not fruit allergy with DQB1 *0202, DRB1 *0701 and *1101, were demonstrated. CONCLUSIONS: Latex-fruit allergy is associated with HLA-DQB1 *0201, DRB1 *0301, and *0901, as well as with HLA-DR functional group E, whereas latex-not-fruit allergy is associated with DQB1 *0202, and with both DRB1 *0701 and *1101 alleles.

Adult↗
PubMed2002

HLA class II markers and clinical heterogeneity in Swedish patients with primary biliary cirrhosis.

Genetic susceptibility to PBC can, at least in part, be ascribed to the major histocompatibility complex. The relevance of immunogenetic markers for the clinical presentation and course, however, is unclear. Thus, the aim of this study was to investigate the contribution of HLA class II genes to susceptibility, clinical presentation and course of disease in PBC patients. HLA genotyping for HLA-DRB1, -DQB1 and -DPB1 was carried out in a total of 99 Swedish PBC patients and 158 controls. Clinical parameters including epidemiologic variables, signs and symptoms of PBC-related liver disease and histologic data were collected and analyzed in 92 patients at study entry and at follow-up five years later. Significant clinical heterogeneity was seen among PBC patients upon study entry. Although a significant disease association was seen for HLA DRB1*08 and DQB1*0402, immunogenetic markers identified neither a particular subset of patients nor an association with the clinical course of the disease. HLA-DRB1*08 and DQB1*0402 provide the strongest immunogenetic influence in PBC. However, this association is not restricted to any particular, clinically defined subgroup of patients and it is not predictive for the course of the disease.

Adult↗
PubMed1999

Evolution of HLA-class I compared to HLA-class II polymorphism in Terena, a South-American Indian tribe.

We have studied the HLA alleles of 60 unrelated healthy Terena and 10 Terena families. They are members of an isolated Brazilian tribe located in Mato Grosso do Sul (South Central Brazil). Six novel alleles were found in this population: HLA-A*0219 (gf = 0.02), A*0222 (gf = 0.15), HLA-B* 3520 (gf = 0.01), B*3521 (gf = 0.03), B*3912 (gf = 0.03) and B*4803 (gf = 0.16). Five of the six novel alleles differ from their putative progenitors by amino acid replacements in residues that contribute to the pockets of the peptide-binding site. Many of the variants defined by molecular methods were not identified correctly by serological typing. We calculated heterozygosity values (H) for HLA-A, -B, -C, DRB1, DQB1 and DPB . The highest values were observed at the HLA-B locus, followed by HLA-A, -DRB1 and DQB1. Residue positions 9, 24, 45, 62, 67, 95, 114, 116, 156, and 163 of HLA class I showed heterozygosity values greater than 0.50. Nine of them contribute to the peptide-binding specificity pockets and one to the T cell receptor binding site. If HLA antigens are useful for defense against pathogenic agents, heterozygosity would offer an advantage by allowing binding of a larger repertoire of peptides to the class I molecules. Individuals that are heterozygous at these positions would probably have a wider repertoire of peptide presentation to T cells. The observed results including the presence of novel alleles in the class I HLA loci suggest a functionally significant, more rapid evolution of class I compared to class II loci in this South American isolated population.

Alleles↗
PubMed2000

Association of hypersensitivity to the nematode Anisakis simplex with HLA class II DRB1*1502-DQB1*0601 haplotype.

Anisakiasis as well as allergic and anaphylactoid reactions to Anisakis simplex antigens are recently identified clinical entities. They are relatively frequent in countries with habitual raw food consumption, often in the form of large amounts of fish and sea food products. In this communication the relationship between HLA class II alleles and the IgE-specific immune response to A. simplex allergen was studied in a defined population in Northern Spain. Individuals with immediate-type Anisakis hypersensitivity and healthy controls were examined for HLA-DRB1, DQB1 and DQA1 alleles by sequence-specific oligonucleotide probe typing. Analysis of the HLA data among patients revealed increased phenotypic frequencies for DRB1*1502 and DRB1*0404 compared to healthy controls (p < 1 x 10(-7) and < 0.01, respectively). Analysis of haplotypic frequencies showed that the DRB1*1502-DQB1*0601 haplotype is significantly higher in patients with Anisakis hypersensitivity in comparison with the control population from the same region (p < 4 x 10(-8)). The data suggest that this haplotype can be considered to be a susceptibility factor for hypersensitivity to A. simplex antigens.

Animals↗
PubMed2005

Analysis of B- and T-cell clonality and HLA class II alleles in patients with idiopathic thrombocytopenic purpura: correlation with Helicobacter pylori infection and response to eradication treatment.

Many authors have recently found a positive correlation between Helicobacter pylori infection and idiopathic thrombocytopenic purpura (ITP), the most common autoimmune hematological disorder. In order to clarify the pathogenic mechanism of H. pylori-associated ITP, we have investigated 52 consecutive ITP adult patients for Helicobacter pylori infection, B- and T-cell clonality and HLA class II alleles. Thirty-four ITP patients (65.4%) were infected by H. pylori and bacterium eradication was accompanied by a long-term platelet response in 17 (53.1%) of them. A B-cell clonality was found in three patients (5.8%, two patients H. pylori-negative and one patient H. pylori-positive). The ITP patients with H. pylori infection showed a HLA-DRB1*11, *14 and -DQB1*03 frequencies significantly higher and a -DRB1*03 frequency significantly lower than in H. pylori-negative patients. Moreover, an HLA-DQB1*03 pattern was associated with a higher probability of platelet response to eradication treatment. If our study documents the efficacy of eradication treatment in H. pylori-infected ITP patients, it may also help to identify different subgroups of ITP patients with probably different pathogeneses of thrombocytopenia and, finally, different responses to eradication treatment.

Adult↗
PubMed1997

European results of matched unrelated donor bone marrow transplantation for chronic myeloid leukemia. Impact of HLA class II matching. Chronic Leukemia Working Party of the European Group for Blood and Marrow Transplantation.

We have retrospectively analyzed the impact of prognostic factors on the outcome of serologically HLA-matched unrelated donor (UD) BMT for CML. For this purpose, we have studied a cohort of 366 patients transplanted in Europe between January 1985 and December 1994. The median age of the 211 males and 155 females was 34 years; 238 patients were transplanted in first chronic phase and 116 in advanced phases. The median interval from diagnosis to BMT was 827 days. GVHD prophylaxis consisted of CsA and MTX in 202 patients or of ex vivo or in vivo T cell depletion (TCD) in 129. Recently, DNA-based methods of HLA-class II typing have been used to improve donor selection. We obtained complete data on 300 donor/recipient (D/R) pairs. Among them, we have identified three groups of patients, according to specific HLA-DRB1 D/R compatibility. Two hundred and ten patients received marrow from donors identical for HLA-DRB1 (group 1). Thirty-one patients received BMT from a donor who was HLA-DRB1 mismatched (group 2) and 59 from a donor in whom specific HLA-DRB1 typing was not performed (group 3). The overall survival was 37 +/- 3% at 2 years and leukemia-free survival (LFS) was 31 +/- 3%. In univariate analysis, five variables had a favorable effect on LFS: transplant in first chronic phase (P = 0.0001), time interval from diagnosis to BMT shorter than the median (P = 0.01), prophylaxis of GVHD without TCD (P + 0.001), acute GVHD < grade III (P = 0.0009) and HLA-DRB1 D/R matching (P = 0.0001). Transplant-related mortality (TRM) was 49 +/- 4% in group 1, 79 +/- 8% in group 2 and 80 +/- 6% in group 3 (P = 0.0001). Multivariate analysis confirmed that HLA-DRB1 matching was the most significant factor influencing survival (P = 0.04), LFS (P = 0.013) and TRM (P = 0.0049). From these results, we have defined a 'good risk' group, ie patients transplanted in first chronic phase, from an HLA-DRB1 matched donor, without TCD as prophylaxis against GVHD. The 2 year LFS, TRM and relapse incidence for this group were 51 +/- 5%, 47 +/- 5% and 2 +/- 2%, respectively. This suggests that the long-term outcome of patients with favorable prognostic features can approach that of patients transplanted from geno-identical siblings. In contrast, the TRM for patients transplanted for advanced disease from non HLA-DRB1-identical donors was 94%. Such a high TRM clearly indicates that UD BMT is not justifiable for these individuals.

Adolescent↗
PubMed2006

[Familial pemphigus vulgaris: immunogenetic study of HLA class II antigens].

INTRODUCTION: Pemphigus vulgaris (PV) is a rare autoimmune bullous disease that affects the skin and mucosae, characterized by the presence of antibodies against desmoglein 3, that causes acantholisis and formation of intraepidermal blisters. Observation of PV cases in several members of the same family suggests the existence of genetic factors that contribute to susceptibility to suffer the disease. However, very few cases of familial PV have been described. Based on its autoimmune nature, many studies have found an association between PV and the HLA class II allele, specifically with the HLA-DRB1*0402 DQB1*0302 and HLA-DRB1*1401 DQB1*0503 haplotypes that bestows a significant risk of disease. OBJECTIVES: Study of three families with PV. PATIENTS AND METHODS: In this study, we present three families, with a total of 7 patients, diagnosed of familial PV. HLA antigens were determined with the PCR (polymerase chain reaction) technique in several members of these families. RESULTS: All the subjects affected were positive for HLA DR4 and HLA DR14. The fact that different families with PV are associated with identical haplotypes and that healthy siblings of the patients have the same haplotype is of special interest. CONCLUSION: These results support the concept of genetic predisposition in this rare disease.

Adult↗
PubMed1999

HLA class II polymorphism in cystic fibrosis. A possible modifier of pulmonary phenotype.

Evolution of lung damage is highly variable in cystic fibrosis (CF) even in patients with the same cystic fibrosis transmembrane conductance regulator (CFTR) mutations. The analysis of genetic factors other than CFTR may help our understanding of genotype-phenotype relationships in CF. As human leukocyte antigen (HLA) class II polymorphism has been associated with a number of diseases including autoimmune and inflammatory diseases, asthma, and allergy, we investigated the possibility that HLA polymorphism contributes to CF-associated pulmonary inflammation. Among the 98 adult CF patients tested, the genotypic frequencies of DR4 and DR7 alleles (serologic group DR53) and DR7/ DQA*0201 haplotype were higher than in 39 selected control subjects without atopy (p </= 10(-)6, relative risk [RR] = 22, and p </= 5.10(-)4, RR = 27, respectively) and in a random population. No significant difference of these allelic distributions was found according to the CFTR genotype. In the CF patients, the DR7 allele was significantly associated with an increase in total IgE and with chronic Pseudomonas aeruginosa colonization (100% of DR7 versus 83% of non-DR7 patients being colonized, p < 0.05). Our results suggest that genetic factors known to modulate the immune response might contribute to chronic infection with Pseudomonas, increased total IgE, and pulmonary outcome in CF.

Adult↗
PubMed1996

Met-11 of HLA class II DP alpha 1 first domain associated with onchocerciasis.

Human infection with the pathogenic tissue nematode Onchocerca volvulus may result in a spectrum of clinical manifestations or in a putatively immune condition. A methionine at amino acid position 11 of the HLA class II DP alpha 1 chain correlates with the occurring disease after infection (relative risk 3.3). The alternative alanine at position 11 is, conversely, associated with protection from disease ("relative protection' 3.5). DPA1*0301 is associated with the localized form of disease after O. volvulus infection.

Amino Acid Sequence↗
PubMed2003

Polymorphisms of HLA class II predispose children and adolescents with type 1 diabetes mellitus to autoimmune thyroid disease.

To determine the prevalence of autoimmune thyroid disease (AITD) in children and adolescents with type 1 diabetes mellitus (DM), and assess whether the development of AITD is correlated with specific DQ-A and DQ-B loci of the HLA class II antigens, we analyzed thyroid function using anti-thyroid antibodies and HLA-DQ-A and -DQ-B polymorphisms in 69 patients with type 1 DM, in 75 normal healthy controls, and in 21 patients with AITD but without type 1 DM. Eighteen patients (26%) in the diabetic patients had AITD. In the diabetic patients, DQA1*0301 and DQB1*0302 occurred more frequently than in controls [DQA1*0301: OR = 1.939, 95% CI = 1.210-3.109 (P = 0.008, P(c) (corrected P) < 0.05); DQB1*0302: OR = 2.558, 95% CI = 1.354-4.832 (P = 0.005, P(c), > 0.05)]. Compared with controls, non-diabetic subjects with AITD showed higher frequency of DQA1*0301 (P(c), < 0.05) and DQB1*0601 (P(c) > 0.05), but these alleles were not contributing factors in the development of AITD in diabetic patients. In diabetic patients, DQB1*0201, known as susceptible allele of type 1 DM was not a contributing factor in the development of AITD in diabetic patients. Unlike DQB1*0201, DQB1*0401 was more frequently found in diabetic patients with AITD than in controls [OR = 4.053, 95% CI = 1.607-10.221 (P = 0.0017, P(c) < 0.05)] or than in non-diabetic AITD patients [OR = 15.769, 95% CI = 1.905-130.530(P = 0.002, P(c) < 0.05)]. In non-diabetic subjects, DQB1*0401 did not provide susceptibility for AITD. Our results suggest that HLA DQB1*0401 is a predisposing genetic marker for the development of AITD in patients with type 1 DM in Korea.

Adolescent↗
PubMed1993

A functional basis for the association of HLA class II genes and susceptibility to multiple sclerosis: cellular immune responses to myelin basic protein in a multiplex family.

This study has examined the cellular response to myelin basic protein (MBP) in a multiplex family with multiple sclerosis (MS). A total of 81 MBP-specific T cell lines (TCLs) were derived from three affected siblings and four healthy siblings. No difference was observed in estimated precursor frequencies of MBP-specific TCLs or peptide specificity of TCLs when comparing affected and unaffected siblings. MBP-specific TCLs from affected siblings, however, were restricted to the DRw15/DQw6 allele more frequently than those from unaffected siblings (P < 0.02). These data suggest that restriction of autoantigen-specific T cells may be the functional basis for disease susceptibility related to HLA class II inheritance.

Adult↗
PubMed1994

Association of particular HLA class II alleles, haplotypes and genotypes with susceptibility to IDDM in the Belgian population.

Using a highly discriminatory DNA typing technique, based on the polymerase chain reaction and reverse dot blot hybridization, more refined results were obtained on the association of particular HLA class II alleles, haplotypes and genotypes with insulin-dependent diabetes mellitus in the Belgian population. The previously reported predisposing effect for the DRB1*0301 encoded DR3 serologic specificity was confirmed and could be assigned to the DRB3*0200 encoded DR52b serologic specificity. A second high risk haplotype, DRB1*0401-DQB1*0302 encoding the DR4-DQ8 serologic specificity, accounted for increased susceptibility both in the total insulin-dependent diabetic population and among DR4-positive patients. Moreover, we found that these DR4 associated DRB1 and DQB1 alleles act as independent risk factors. A possible role for the DPB1 locus can be rejected since the observed predisposing effect for DPB1*0202 probably occurred due to linkage disequilibrium of this allele with DRB1*0301. Particular extended haplotypes accounted for the decreased relative risk observed for the DR2, DR11 and DR13 serologic specificities. The highest relative risk was observed for those DQA1/DQB1 genotypes, allowing for the formation of 4SS (DQ alpha Arg52+/DQ beta Asp57-) heterodimers.

Adolescent↗