HLA-DR Genotypes Research Articles

Lack of evidence of a significant association between HLA-DR, DQ and DP genotypes and atopy in families with HDM allergy

Lack of evidence of a significant association between HLA-DR, DQ and DP genotypes and atopy in families with HDM allergy

HLA-DR, DQ and anti-GAD antibodies in first degree relatives of type I diabetes mellitus

The differential antibody response to glutamic acid decarboxylase (anti-GAD) and to islet cell cytoplasm (ICA) according to HLA-DR and DQ genotypes were examined in 28 Spanish patients with Type I diabetes mellitus (11.1 ± 10.4 year diabetes duration) and their 41 first degree non-diabetic relative. Anti-GAD was detected by radioimmunoprecipitation and ICA by indirect immunofluorescence and HLA-DR/DQ alleles were assigned by PCR and sequence specific oligonucleotide probes. The frequency in patients of positivity for ICA was 7.1% and of anti-GAD − 64.3%, and in relatives, the frequency of ICA − was 4.9%, and anti-GAD + 9.8%. Concurrent positivity for ICA and anti-GAD existed in only one patient, and in none of the relatives. We confirm for a Spanish population the high frequency of risk genotypes for Type I, involving DR3, DR4 and DQB1*0302 (DQ8), which were present in 26 of 28 (93%) patients and 32 of 41 (78%) relatives. The most frequent genotypes were DR3/DQB1*0201/DQA1*0501-DR4/DQB1*0302/DQA1*0301(9 patients, 32%; 6 relatives, 15%) DR3/DQB1*0201/ DQA1*0501-DR3/DQB1*0201/DQA1*0501 (5 patients, 18% 7 relatives, 17% and DR3/DQB1*0201/DQA1*0501-DR1/DQB1*0501/DQA1*0101 (5 patients, 18%; 1 relative, 2%). Positivity for anti-GAD or for ICA did not correlate with gender, or age at onset or duration of DM. The distribution of high risk HLA genotypes were similar regardless the anti-GAD or anti-ICA status either in patients or in their relatives.

P868 - HLA-DR genotypes and specific immunoglonulin E responses to Derp 1 and Lolp 1

P868 - HLA-DR genotypes and specific immunoglonulin E responses to Derp 1 and Lolp 1

HLA class II genotypes in Leber's hereditary optic neuropathy

There is an association between Leber's hereditary optic neuropathy (LHON) and a multiple sclerosis-like illness, raising the possibility of autoimmune pathogenetic mechanisms in LHON. We therefore investigated the frequency of HLA-DR genotypes in members of 79 families with LHON, defined by the presence of a pathogenic mitochondrial DNA mutation. There was no association between LHON and any HLA-DR genotype. Furthermore, affected relative pairs did not share HLA genotypes more than discordant pairs. We conclude that the HLA-DR locus is not a major genetic determinant for the development of blindness in LHON.

Rapid DNA crossmatch analysis of HLA class II genotypic polymorphisms by temperature gradient gel electrophoresis in unrelated bone marrow donor selection.

The present paper demonstrates the usefulness of the temperature gradient gel electrophoresis (TGGE) as a precise method for the rapid identification of HLA-DR full matched donors by molecular crossmatch analysis. The resulting TGGE fingerprints are highly diverse for different HLA-DR genotypes and identical for samples with identical HLA-DR type, as shown for a panel of 25 randomly selected PCR-SSO pretyped DNA samples. In addition, TGGE analysis of a panel of homozygous typing cell lines (HTCs) established, that even subtle differences in the DR4 subtypes are detectable by TGGE crossmatch analysis. Furthermore, TGGE crossmatch analysis of unrelated donor/patient pairs demonstrated, that only HLA-DR identical patient/donor combinations showed identical TGGE patterns. Thus crossmatch analysis by TGGE presents a novel basis for a rapid and safe unrelated bone marrow donor selection strategy. Only HLA class I identical donors which also show HLA-DR identity in the TGGE crossmatch test are selected for the final confirmation of the HLA class II genes by a suitable DNA subtyping method.

Lack of association of T cell receptor V beta 8 polymorphism with rheumatoid arthritis in United Kingdom and Italian white patients.

To study if the reported association of a BamH I 2kb RFLP of the T cell receptor V beta 8 gene with DR4+ rheumatoid arthritis patients is found in non-American white populations. The frequency of this RFLP in two different populations was analysed. Eighty one northern Italians were studied for HLA-DR genotypes and V beta 8 polymorphism, and 29 DR4+ British white patients were studied for V beta 8 polymorphism. No association between the V beta 8 RFLP and DR4 was found with rheumatoid arthritis in both groups. The reported V beta 8-DR4 association is not generally applicable. The lack of association in our populations may be due to genetic differences, or to differences in factors which shaped the T cell repertoire.

Proliferative responses of peripheral blood mononuclear cells from patients with Graves' disease to synthetic peptides epitopes of human thyrotropin receptor.

In Graves' disease thyrotropin receptor (TSH-R) autoantibodies cause hyperthyroidism. Production of TSH-R autoantibodies must be controlled by specific T cells. In this study we investigated T cell responses to 33 peptides corresponding to the sequence of the extracellular domain of human TSH-R. Peripheral blood mononuclear cells (PBMC) from 12 patients with Graves' disease and 9 healthy subjects were cultured with peptides for 3 days. The proliferative responses of PBMC were analyzed by measurement of [3H]thymidine incorporation. A stimulation index (SI; mean cpm in the presence of peptide/mean cpm in culture medium alone) of more than 3 was considered a positive response. When PBMC were stimulated with a pool containing all synthesized peptides, the mean SI of patients was significantly higher than that of controls (4.50 +/- 3.95 vs. 1.44 +/- 0.60; p < 0.05). When PBMC were cultured with individual peptides, PBMC from patients responded predominantly to two peptides, corresponding to sequence segments 152-157 (5 patients) and 207-222 (4 patients). No PBMC from controls responded to these two peptides. There was no clear correlation between the HLA-DR or HLA-DQ genotype and the stimulatory sequence segments. These results suggest that (a) TSH-R-specific T cells are present in peripheral blood of patients with Graves' disease, and (b) sequence segments 152-157 and 207-222 may be T cell epitopes of the human TSH-R in Graves' disease.

Polymorphism in the Human Complement C4 Genes and Genetic Susceptibility to Autoimmune Hepatitis

Susceptibility to autoimmune hepatitis is associated with the HLA-DR3 and DR4 haplotypes, but which genes are directly involved in the pathogenesis, has not been established. Low levels of complement component C4 and elevated frequencies of C4 null allotypes have been described in patients, suggesting that the C4 genes, which are closely linked with the HLA loci, may play a role. We therefore examined restriction fragment length polymorphisms in the C4 and 21-hydroxylase genes, and determined HLA-A and B phenotypes, and HLA-DR, DQ and DP genotypes in a large series of Caucasoid patients with autoimmune hepatitis and matched controls. A DNA deletion of the C4A gene and the 21-hydroxylase A pseudogene was found to be present in 50% of patients compared to 23% of controls (Pc < 0.005, relative risk = 3.3). This increase, however, appears to be due to linkage disequilibrium with HLA-DR52a which was most strongly associated with the disease. Complete C4A deficiency, determined by homozygosity for the deletion increased the risk to 18.1 (16% versus 1%, Pc < 0.005), suggesting an additional role for C4 in disease susceptibility. C4 deletions were associated with an increased mortality and tendency to relapse whilst on treatment but did not correlate with age of onset of disease. Our data suggest that MHC-encoded susceptibility to autoimmune hepatitis is polygenic, involving the HLA-DR genes plus other loci, and C4 deficiency may be a marker of disease susceptibility and/or severity.

MOLECULAR COMPATIBILITY AND RENAL GRAFT SURVIVAL—THE HLA DRB1 GENOTYPING1

HLA DRB1 allelic types were determined by using sequence-specific oligonucleotides for the analysis of 91 renal donor-recipient pairs that were followed for 30 months. The Kaplan-Meier method was used to evaluate graft survivals (GS) of the matched and mismatched groups. The degree of compatibility was measured by allelic type matches and mismatches of the pairs. Furthermore, HLA DR genotypes were categorized into five groups, namely DR1, DR2, DR4, the group that also has the DRw52 allele, and the group of DR7, DR9, and DR10. All types within a group were considered a match. Serotypes of the same study group were also included for comparison. Associations of superior GS with compatible DRB1 allelic types, serotypes, and grouped DRB1 types were observed. A significantly higher GS rate was found in donor-recipient pairs when HLA DRB1 types were analyzed by group mismatching (P = 0.03) rather than type mismatching (P > 0.34). Because of the numerous allelic types that can be assigned on the basis of nucleotide sequence variations, a larger number of donor-recipient pairs is required to derive statistically significant results.

HLA genotyping of colorectal carcinoma in the Chinese population

The HLA-DR genotypes of 61 primary colorectal carcinomas obtained from patients of Chinese origin were determined by using DNA-RFLP. No increase or decrease of a particular HLA genotype could be ascertained with the disease, although we detected an antigen frequency of 29.5% for the serologically ill-defined DR“X3” specificity. We identified and sequenced HLA-DRB1 and DRB3 genes from the DR“X3” haplotype. The DR“X3” DRB1 gene was found to be identical to DRB1 ∗1201 (Dr5{w12}). A unique observation is its unusual linkage with DRB3 ∗0101 (DRw52a) or DRB3 ∗0301 (DRw52c) instead of the usual linkage with DRB3 ∗0201/2 (DRw52b). These associations are rare in whites and blacks.

Increased numbers of T cells recognizing multiple myelin basic protein epitopes in multiple sclerosis.

Myelin basic protein (MBP)-autoreactive T cells have a crucial pathogenetic role in experimental allergic encephalomyelitis (EAE) and certain MBP epitopes may be immunodominantly recognized. The heterogeneity and quantity of the T cell response to different epitopes of MBP in multiple sclerosis (MS) and non-MS controls is not so clearly defined. We now study T cell reactivity to six different peptides of MBP in MS compared to controls in short-term cultures of blood mononuclear cells by measuring numbers of T cells that secrete interferon-gamma in response to antigen. In comparison with controls, MS patients showed dramatically increased numbers of MBP peptide-reactive T cells with mean values varying between 10.4 and 22.5 per 10(5) blood mononuclear cells. Among those MBP peptides examined (amino acid 1-20, 63-88, 89-101, 96-118, 110-128 and 148-165), no single peptide is preferentially recognized. Neither is any preferential response apparent after subdivision of the MS patients according to their HLA-DR genotype. Our findings suggest that a quantitative increase of a broad repertoire of myelin-autoreactive T cells with capacity to secrete IFN-gamma can be important for the pathogenesis of MS.

Immunogenetics of early-onset insulin-dependent diabetes mellitus among the Japanese: HLA, Gm, BF, GLO, and organ-specific autoantibodies — the J.D.S. study

The Japan Diabetes Society (JDS) conducted a multicenter study on the immunogenetics of early-onset insulin-dependent diabetes mellitus (IDDM) of the Japanese. Human leukocyte antigen (HLA), properdin factor B (BF), immunoglobulin heavy-chain complex (Gm), and glyoxalase of erythrocytes (GLO) were typed, and organ-specific autoantibodies, including islet cell antibody (ICA), were assayed in 159 Japanese IDDM patients and their family members and in 258 healthy Japanese controls. The HLA-DRw9 phenotype and HLA-Bw61 DRw9 haplotype were significantly increased among the patients with autoantibodies other than ICA but with no autoimmune diseases (RR = 5.84, c P < 0.001; and RR = 7.45, P < 0.001), whereas the HLA-DR4 phenotype and HLA-Bw54 DR4 haplotype were significantly increased in those without either the autoantibodies or autoimmune diseases (RR = 2.64, c P < 0.001; and RR = 4.55, P < 0.001). The HLA-DR4 phenotype was significantly increased in the patients with autoimmune thyroid diseases (RR = 6.21, c P < 0.05). In all groups of patients, the HLA-DR2 phenotype was significantly decreased, and the relative risk of the HLA-DRw9 DR4 genotype was highest among all HLA-DR genotypes. No significant association was found between HLA type and the duration or incidence of ICA. Gm types of g and gft were significantly increased in the patients with the autoantibodies (RR = 2.11, P < 0.05; and RR = 34.11, P < 0.05), whereas the BF-F phenotype was significantly decreased in the patients either with or without autoantibodies (RR = 0.43, P < 0.05; and RR = 0.46, P < 0.05). There was no association between IDDM and GLO type. These data indicate that immunogenetic bases underlying IDDM of the Japanese are heterogeneous, as are those in Caucasians.

Immunogenetic heterogeneity in type 1 (insulin-dependent) diabetes among Japanese HLA antigens and organ-specific autoantibodies.

HLA phenotypes and haplotypes in relation to organ-specific autoantibody responses were studied in 82 Japanese patients with Type 1 (insulin-dependent) diabetes. HLA-DRw9 antigen and HLA phenotype of DRw9/X (X:not DR4) were increased in patients with organ-specific autoantibodies other than islet cell antibody (CP less than 0.02, RR = 4.02 and p less than 0.05 RR = 2.30, respectively); whereas HLA-DR4 antigen and HLA phenotype of DR4/X (X: not DRw9) were increased in those without the autoantibodies (CP less than 0.001, RR = 3.95 and p less than 0.01, RR = 2.46, respectively). HLA haplotype of Bw61-DRw9 was increased in patients with the autoantibodies (p less than 0.005, RR = 4.94), and HLA haplotype of Bw54-DR4 was increased in those without the autoantibodies (p less than 0.001, RR = 5.52). The relative risk of HLA-DR4/DRw9 was the highest among all HLA-DR phenotypes or genotypes in patients either with or without the autoantibodies. No association was, however, found between the incidence of islet cell antibody and HLA-DR phenotypes. These findings suggest that Type 1 diabetes among Japanese is immunogenetically heterogeneous as is Type 1 diabetes among Caucasians; and the differences in HLA-association of Type 1 diabetes among ethnic groups might give a clue to understanding of a role of HLA-antigens in the development of Type 1 diabetes.

HLA and insulin gene associations with IDDM

The HLA DR genotype frequencies in insulin-dependent diabetes mellitus (IDDM) patients and the frequencies of DR alleles transmitted from affected parent to affected child both indicate that the DR3-associated predisposition is more "recessive" and the DR4-associated predisposition more "dominant" in inheritance after allowing for the DR3/DR4 synergistic effect. B locus distributions on patient haplotypes indicate that only subsets of both DR3 and DR4 are predisposing. Heterogeneity is detected for both the DR3 and DR4 predisposing haplotypes based on DR genotypic class. With appropriate use of the family structure of the data a control population of "unaffected" alleles can be defined. Application of this method confirms the predisposing effect associated with the class 1 allele of the polymorphic region 5' to the insulin gene.

10 AN HLA-DQ ALPHA ALLELE IDENTIFIED AT DNA AND PROTEIN LEVEL IS STRONGLY ASSOCIATED WITH COELIAC DISEASE

Susceptibility genes for coeliac disease are associated with certain HLA-DR genotypes. More recent studies also show strong association with some HLA-DQ alleles. We have examined the presence of disease associated HLA-DQ alleles by restriction fragment length polymorphism (RFPL) with the help of a HLA-DQ alpha cDNA probe. This probe showed upon hybridization a highly significant discrepancy between the RFLP of coeliac disease patients and healthy controls. The 4.0 kb. Bgl II restriction fragment was present in 97% of coeliac disease patients (n=30), compared to 56% in a healthy control population (n=72) (RR= 14.9; p<0.0005). This fragment is associated with HLA-DR3, -5, some DRw8, and DRw14Dw16. This was confirmed by the analysis of the panel of 72 homozygous typing cells obtained from the Xth International Workshop on Histocompatibility Testing. At the product level all coeliac disease patients tested sofar have one DQ alpha chain in common, designated HLA-DQ alpha 2.3, which is associated with the 4.0 kb Bgl II fragment. This HLA-DQ alpha allele identified at the DNA level and product level seems to be a better marker for genetic susceptibility to develop coeliac disease than those available sofar.

Excess of DR3/4 in type I diabetes. What does it portend?

The HLA-DR genotypes of 158 new type I diabetic probands from simplex families are compared with those of 43 multiply affected sibships. There were no significant differences in the gene frequencies of the insulin-dependent diabetes mellitus (IDDM)-associated alleles, DR3 and DR4, and whereas the DR3/4 heterozygotes were as frequent among simplex probands as among the first affected of multiplex sibships, subsequently affected sibs displayed lower frequencies of this genotype in this as well as in previously reported samples, indicating that the excessive risk associated with DR3/4 heterozygosity depends on the order of affection and thus on environmental factors. It is proposed that the penetrance of the susceptibility gene is enhanced by epistatic effects of this genotype and that this enhancement is strongest under conditions of low environmental liability. Thus, the excessive risk for DR3/4 individuals appears to depend on secondary interactions between DR and the environmental factors that trigger the onset of this disease and does not in itself indicate the existence of distinct susceptibility alleles in coupling with these genes, i.e., of genetic heterogeneity or overdominance.

HLA haplotype sharing in IDDM affected sib pairs as a function of HLA DR genotype.

HLA haplotype sharing in IDDM affected sib pairs as a function of HLA DR genotype.

Islet-cell antibodies (ICA-CFICA) and HLA genotypes in 107 IDD patients and their first-degree relatives

The prevalence of ICA and CFICA in relation to HLA-DR genotypes was analyzed in 107 insulin-dependent diabetic (IDD) patients with a duration of IDD ranging from onset to 30 years, and 247 nondiabetic first-degree relatives. In 46 patients tested at onset of IDD, the prevalence of ICA and of CFICA was 61 and 50%, respectively; with the longer duration of IDD, the prevalence of CFICA decreased more rapidly than that of ICA. No significant association was observed between ICA and any HLA allele in patients tested from onset till 2 years after onset. However, a higher prevalence of ICA was found in DR3 positive patients with a duration of IDD of more than 2 years ( p < 0.02). Among the healthy relatives, the prevalence of ICA was 7% in parents and 13% in siblings; one out of 101 siblings had CFICA. No association was found between ICA and any HLA marker. The presence of ICA in sibs was independent of the number of haplotypes they shared with the IDD proband: among the 13 ICA-positive healthy sibs, one shared 2 haplotypes, nine shared 1 haplotype and three shared no haplotype with the proband, which is not different from the random distribution.

The search for heterogeneity in insulin-dependent diabetes mellitus: evidence for familial and nonfamilial forms.

Using five different published sets of data, we looked at the distribution of HLA-DR genotypes among diabetic probands. It was possible to reject dominant inheritance at the HLA-associated locus, but some of the data were compatible with recessive inheritance while some were not. An attempt to reconcile the conflicting data by proposing a three-allele model apparently failed. It proved possible to resolve some of the conflicting data by proposing that simplex families represent primarily a recessive form of insulin dependent diabetes mellitus (IDDM) while multiplex families represent primarily two other subforms: one showing three-allele inheritance and one not. We also propose that the HLA locus involved in IDDM mediates the effect of an environmental agent on a second disease locus.

Sensitization of human lymphocytes in vitro: genetic restriction of secondary T cell responses is dictated by the HLA-DR phenotype of antigen-presenting cells.

Antigen-specific proliferation of human T cells sensitized in vitro was found to be macrophage dependent and HLA-DR restricted. Primary sensitization or secondary restimulation did not occur in the absence of antigen-presenting macrophages. The macrophage requirement for secondary restimulation was restricted by specificities shared between macrophages used for primary sensitization and T cells of the HLA-DR locus. Moreover, the magnitude of the response to antigen appeared to be related to the number of HLA-DR haplotypes shared between antigen-presenting cells in primary and secondary cultures. This observation could be attributed to a clonal response of the T cells with respect to HLA-DR on macrophages. Using HLA-DR 3/5 heterozygous KLH-primed T cells, elimination of cells responsive to antigen-pulsed HLA-DR 3/3 macrophages by thymidine suicide techniques left intact responsiveness to antigen-pulsed HLA-DR 5/5 macrophages. Tp determine whether the genetic restriction was dictated by the HLA-DR genotype of the responding lymphocytes or the HLA-DR phenotype of the responding lymphocytes or the HLA-DR phenotype of the antigen-pulsed macrophages, allogeneic macrophages were used to present antigen in primary culture. After elimination of alloreactive cells, proliferation in secondary cultures was found to be dependent on HLA-DR determinants shared between macrophages used for secondary restimulation and those used in primary sensitization, regardless of the HLA-DR genotype of the responding T lymphocytes.