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PubMed1990

Different HLA DR-DQ associations in subgroups of idiopathic myasthenia gravis.

We have investigated the HLA-DRB and -DQB gene polymorphism in 131 myasthenia gravis (MG) patients. The HLA genotypes in these patients were assigned by means of restriction fragment length polymorphism (RFLP)-defined DR-DQ haplotypes, correlating to serologic HLA class II typing. Using this technique we could, among randomly selected non-thymomatous (NT)-MG patients, confirm the strong association to DR3, and 70% of the patients were found to carry a specific DR3-positive DR-DQ haplotype, T-3.1. Furthermore, an analysis of T-3.1- NT-MG patients revealed that 59% were T-4.1+ (DR4, DQw8). Thymic hyperplasia was found in approximately 85% of the T-3.1+, as well as of the T-4.1+/3.1- patients. As previously observed, we found a clear dominance of females among the T-3.1+ NT-MG patients. However, among T-4.1+/3.1- patients, males were as common as females. Furthermore, the T-4.1+ patients were significantly older at the onset of disease than those who were T-3.1+. In female MG patients, the DRw15-Dw2-positive haplotype T-2.1 was strongly correlated with the presence of thymoma (T-MG). These data indicate that the HLA associations in early vs late onset of NT-MG are different, and that female patients with and without thymoma differ from each other with regard to HLA markers. Thus, at least three different HLA DR-DQ associations are found in subgroups of idiopathic MG.

Female↗
PubMed1995

HLA-DRB1 molecules and antigenic experience shape the repertoire of CD4 T cells.

Forces influencing the composition of the mature TCR repertoire have been well studied in the mouse. In particular, the contribution of MHC molecules in negative and positive selection events of T lymphocytes has been established. To understand whether the allelic polymorphism of HLA-DRB1 molecules can shape the human TCR repertoire, we compared the usage of TCR V beta segments in two cohorts of unrelated individuals who were selected for the expression of HLA-DRB1 alleles. To investigate the potential role of antigenic experience in shaping the TCR repertoire, we compared the usage of V beta gene elements in CD45RO- CD4+ (naive) T cells versus CD45RO+ CD4+ (memory) T cells. A correlation between V beta gene segment usage and HLA-DRB1 alleles could be demonstrated for the repertoire of the naive CD4+ T cells, suggesting a shaping force of the HLA-DRB1 allele on the peripheral TCR repertoire. While the HLA-DRB1 imposed profile in V beta distribution was maintained in CD45RO+ CD4+ T cells, it was less pronounced, indicating that antigenic experience modulates the functional TCR repertoire.

Alleles↗
PubMed2002

Association between the MHC class I gene HFE polymorphisms and longevity: a study in Sicilian population.

Classes I and II human leukocyte antigens (HLA) genes encode highly polymorphic heterodimeric glycoproteins involved in the control of immune responses. The HLA class I gene HFE seemingly no longer participates in immunity because it has lost its ability to bind peptides and it has acquired the ability to form complex with the receptor for iron-binding transferrin by regulating iron uptake by intestinal cells. Thus, it indirectly regulates immune responses too, because iron availability plays a role in specific and non-specific immune responses. The distribution of HFE polymorphisms in Sicilian centenarians and nonagenarians was studied to evaluate if HFE alleles might be represented differently in people selected for longevity. DNA samples were obtained from 106 young controls (age range from 22 to 55 years; 40 men and 66 women) and 35 elderly subjects (age range from 91 to 105 years; seven men and 28 women). Samples were typed for C282Y, H63D and S65C alleles using polymerase chain reaction and sequence specific primers. Among the young individuals, none was heterozygous for the C282Y or for S65C mutation. Twenty-six were heterozygous for H63D mutation. Among the elderly subjects, 11 were heterozygous for the C282Y mutation or for H63D mutation. None was heterozygous for the S65C mutation. No compound heterozygous individuals (C282Y/H63D) were found. A highly significant difference was observed in frequencies of C282Y alleles between the young and the elderly subjects on the whole. By analysing polymorphisms according to gender, heterozygous subjects for C282Y were found both in old men and in old women, but by comparing the allele frequencies to those of young people significance was attained only in women. Concerning H63D polymorphisms, no significant differences were observed, between old and young people, both in men and in women. Possession of C282Y allele, known to be associated with an increase of iron uptake, significantly increases women possibility to reach longevity. Thus, present data adds another piece of evidence to the complex puzzle of genetic and environmental factors involved in control of lifespan expectancy in humans.

Adult↗
PubMed1987

Inhibition by anti-HLA class II monoclonal antibodies of monocyte-dependent T cell proliferation induced by monoclonal antibody OKT3.

The inhibitory effect of monoclonal antibodies (mAb) to monomorphic (locus-restricted and locus-shared) and polymorphic determinants of HLA class II antigens on the monocyte-dependent proliferation of T cells stimulated with mAb OKT3 has been studied. The effect appears to be specific, dose dependent, is not mediated by the Fc portion of mAb and reflects their interaction with the corresponding determinants. The anti-HLA class II mAb do not have to be present in the culture throughout the incubation period, but are essential in early phases of mAb OKT3 T cell activation. Both monocytes and T cells are the targets of the inhibition exerted by the anti-HLA class II mAb. Their inhibitory effect involves several steps in the sequence of events which leads to T cell proliferation, including interleukin (IL) 1 and 2 secretion, and IL2 receptor expression.

Antibodies, Monoclonal↗
PubMed2006

A humanized HLA-DR antibody (hu1D10, apolizumab) in combination with granulocyte colony-stimulating factor (filgrastim) for the treatment of non-Hodgkin's lymphoma: a pilot study.

Apolizumab is a humanized monoclonal antibody against a polymorphic epitope on HLA DRbeta that demonstrated evidence for therapeutic activity in follicular lymphoma patients. In pre-clinical studies, we previously reported that granulocyte colony-stimulating factor (G-CSF) treatment significantly enhanced lymphoma cell killing by HLA class II antibodies, including apolizumab. These results suggested a combination trial of apolizumab and G-CSF (filgrastim). In this trial, we treated six patients with relapsed or refractory 1D10-positive non-Hodgkin's lymphoma with filgrastim and variable doses of apolizumab ranging from 0.15 to 1.5 mg/m2. The combination was clinically well tolerated, with only two patients experiencing grade III/IV hematological toxicity (thrombocytopenia and autoimmune hemolytic anemia). Another patient developed a pruritic skin rash, which was probably a treatment-related grade II skin toxicity. Interestingly, two patients with follicular lymphoma who received intensified apolizumab treatment on a three times weekly schedule experienced prolonged stabilization of their disease for 12 and more than 36 months. In conclusion, this small pilot study suggests that a combination of HLA class II antibodies and G-CSF is clinically feasible.

Aged↗
PubMed1995

Further evidence for an association between schizophrenia and the HLA DQB1 gene locus.

A case-control study was conducted in Singapore, in order to examine a proposed association between schizophrenia and the HLA DQB1 gene locus. The probands were male inpatients of Chinese ethnicity with schizophrenia (ICD-10 criteria, n = 102) and the controls were adults matched for gender and ethnicity (n = 111). Polymorphisms of the HLA DQB1 gene were examined using molecular typing by reverse dot-blotting (MTRB), a novel PCR based method. Among the patients, a positive association with HLA DQB1*0303 (odds ratio 4.46, C.I. 1.63, 12.17), as well as a negative association with HLA DQB1*0602 (odds ratio 0.22, C.I. 0.18, 0.83) was detected.

Adult↗
PubMed1998

Linkage of the MHC to familial multiple sclerosis suggests genetic heterogeneity. The Multiple Sclerosis Genetics Group.

Multiple sclerosis (MS) is a demyelinating autoimmune disease of the central nervous system. While its etiology is not well understood, genetic factors are clearly involved. Until recently, most genetic studies in MS have been association studies using the case-control design testing specific candidate genes and studying only sporadic cases. The only consistently replicated finding has been an association with the HLA-DR2 allele within the major histocompatibility complex (MHC) on chromosome 6. Using the genetic linkage design, however, evidence for and against linkage of the MHC to MS has been found, fostering suggestions that sporadic and familial MS have different etiologies. Most recently, two of four genomic screens demonstrated linkage to the MHC, although specific allelic associations were not tested. Here, a dataset of 98 multiplex families was studied to test for an association to the HLA-DR2 allele in familial MS and to determine if genetic linkage to the MHC was due solely to such an association. Three highly polymorphic markers (HLA-DR, D6S273 and TNFbeta) in the MHC demonstrated strong genetic linkage (parametric lod scores of 4.60, 2.20 and 1.24, respectively) and a specific association with the HLA-DR2 allele was confirmed (TDT; P < 0.001). Stratifying the results by HLA-DR2 status showed that the linkage results were limited to families segregating HLA-DR2 alleles. These results demonstrate that genetic linkage to the MHC can be explained by the HLA-DR2 allelic association. They also indicate that sporadic and familial MS share a common genetic susceptibility. In addition, preliminary calculations suggest that the MHC explains between 17 and 62% of the genetic etiology of MS. This heterogeneity is also supported by the minority of families showing no linkage or association with loci within the MHC.

Alleles↗
PubMed1997

Major histocompatibility complex class II alleles in Kazak and Han populations in the Silk Route of northwestern China.

Genetic polymorphism of the HLA class II loci including the DRB1, DQA1, DQB1 and DPB1 genes was investigated by the polymerase chain reaction-restriction fragment-length polymorphism (PCR-RFLP) method in a Kazak population inhabiting the most northwestern part of China, Urümqi in the Xinjiang Uygur Zizhiqu as well as in a Han population in the same area. Forty-two Kazak and 59 Han unrelated volunteers were enrolled in this study. Among 51 DRB1 alleles tested, 29 alleles were detected, and DRB1*0301 (13.1%) and DRB1*07 (10.7%) in Kazak and DRB1*0901 (11.9%), DRB1*1501 (11.0%) and DRB1*07 (11.0%) in northwestern Han were highly predominant. In 8 DQA1 alleles detected, DQA1*0501 (29.8%) and DQA1*0301 (23.8%) in Kazak, and DQA1*0301 (28.8%) and DQA1*0102 (19.5%) in northwestern Han were the most and the second most common alleles, respectively. Of 18 DQB1 alleles tested, 14 were observed, among which DQB1*0201 and DQB1*0301 were very frequent both in Kazak (23.8% and 21.4%, respectively) and northwestern Han (18.6% and 16.9%, respectively) populations. Of 37 DPB1 alleles tested, 14 were detected. Among them, the frequencies of DPB1*0401 (21.4%), DPB1*0501 (20.2%), DPB1*0402 (19.0%) and DPB1*0201 (16.7%) in Kazak, and those of DPB1*0501 (38.1%) and DPB1*0201 (16.1%) in northwestern Han were highly increased. Several three-locus haplotypes were recognized to predominate significantly, namely DRB1*0301-DQA1*0501-DQB1*0201 (13.1%) and DRB1*0701-DQA1*0201-DQB1*0201 (8.3%) in Kazak; and DRB1*0901-DQA1*0301-DQB1*0303 (11.9%) and DRB1*0701-DQA1*0201-DQB1*0201 (10.2%) in northwestern Han. The dendrogram constructed by the neighbor-joining (NJ) method based on the allele frequencies of the DRB1, DQA1, DQB1 and DPB1 genes of 12 representative populations all over the world including northern Han, southern Han, Manchu and Japanese suggested that Kazak and northwestern Han were the closest to each other, but Kazak was a little farther from the Asian ethnic groups than northwestern Han.

Alleles↗
PubMed2002

Kleine-Levin syndrome: an autoimmune hypothesis based on clinical and genetic analyses.

BACKGROUND: Kleine-Levin syndrome (KLS) is a rare disorder of unknown etiology. Pathophysiologic hypotheses include a hypothalamic dysfunction and abnormalities in the central serotonin and dopamine metabolism. Several clinical symptoms also suggest an underlying autoimmune process. OBJECTIVE: To systematically investigate patients with KLS with reference to the available hypotheses. METHODS: The authors collected clinical, polysomnographic, CSF, CT, and MRI records and analyzed gene polymorphisms of HLA-DQB1, tryptophan hydroxylase (TpH), and catechol-O-methyltransferase (COMT) in 30 unrelated patients with KLS and their families. The genotype data were contrasted with data from a normal control population. RESULTS: Only human leukocyte antigen (HLA)-DQB1*0201 allele frequency was significantly increased in patients with KLS. Three patients with KLS but none of the control subjects were DQB1*0201 homozygous. Two affected subjects from the same family were DQB1*0201 homozygous. In 17 DQB1*0201 heterozygous parents, 11 (64.7%) had transmitted this allele, suggesting a preferential transmission. CONCLUSION: These findings, together with the young age at onset, the recurrence of symptoms, and the frequent infectious precipitating factors, suggest an autoimmune etiology for Kleine-Levin syndrome.

Adolescent↗
PubMed2000

Stronger association with HLA-Cw6 than with corneodesmosin (S-gene) polymorphisms in Swedish psoriasis patients.

Psoriasis vulgaris is strongly associated with certain human leukocyte antigens, especially in early onset. The purpose of this study was to study the HLA-Cw6 allele and its contribution to disease susceptibility in a set of 104 families with at least two affected siblings. A sequencing method was utilized to examine the two exons that build up the antigen binding site of the C locus receptor. DNA from patients homozygous for Cw6 based on haplotype information were sequenced. The results confirmed the identity of the Cw6 allele in affected individuals with the consensus sequence for Cw*0602. We screened the set of families for psoriasis patients homozygous for Cw6 and found 11 individuals with a mean age at onset of 16.1 years. The corresponding figure for the Cw6 heterozygotes was 18.45 years and for the Cw6-negatives 22.36 years. This is indicative of a gene dose effect. We performed a transmission disequilibrium test (TDT) on the Cw6 allele per se, used as a biallelic marker. The analysis resulted in a P-value of 5.3 x 10(-17) (t167/nt45). This greatly exceeds our previous results of a TDT in the region, including microsatellite markers and single nucleotide polymorphisms (SNPs) in the coding part of the S gene (corneodesmosin), which is a suggested candidate gene in the region. The maximum nonparametric linkage (NPL) value was also reached using HLA-C as a marker. We conclude that Cw6 is the allele which shows the highest degree of association with psoriasis in our set of families and we propose that it directly influences the age at onset of the disease rather than increasing the genetic load in accordance with a polygenic theory.

Alleles↗
PubMed2006

[Association of soluble human leukocyte antigen DQB1 with recurrent spontaneous abortion].

OBJECTIVE: To investigate the relationship between the recurrent spontaneous abortion and soluble human leukocyte antigen (HLA) DQB1 gene polymorphism. METHODS: Sixty one cases with recurrent spontaneous abortion were included in study group. Of them, 31 were anticardiolipin antibody (ACA) positive, while 30 were negative. Twenty eight cases were with early abortion, 22 were with late abortion, and 11 were with both early and late abortions. Thirty six women without abnormal pregnancy history were recruited as control group. HLA-DQB1 genotyping was carried out by polymerase chain reaction-restrictive fragment length polymorphism (PCR-RFLP). RESULTS: The frequency of DQB1*0201allele in the study group (16.4%, 20/122) was higher than that in the control group (8.3%, 6/72), but the difference was not statistically significant (P > 0.05). The frequency of 57 site with non Asp in the study group was significantly higher than that in the control group (P < 0.05). The frequencies of both DQB1*0201 and *0303 were significantly different among early abortion, late abortion and both early and late abortion groups (P < 0.05 and P < 0.05). The frequency of DQB1*0201 was significantly higher in the early abortion group than that in the late abortion group (P < 0.01). The frequency of DQB1*0303 was significantly increased in the late abortion group when compared to that in the early group (P < 0.01). The frequency of DQB1*0303 was found to be significantly higher in patients with ACA positive than that in ACA negative group (P < 0.05). CONCLUSION: The 57 site with non Asp may be a gene related to recurrent spontaneous abortions. DQB1*0201 may be correlated to the early abortion, while DQB1*0303 correlated to the late abortion and abortion with ACA positive.

Abortion, Habitual↗
PubMed1995

A molecular analysis of the telomeric end of the major histocompatibility complex. DNA typing of HLA-A3 subtypes and -B7.

A molecular investigation of the HLA-A, -B, -C, I82, D6S128, and D6S265 loci was carried out using RFLP and PCR analyses in 331 healthy individuals, 21 HLA-A3B7 homozygous subjects, and 17 HLA homozygous cell lines. New polymorphic RFLP patterns were noted at the HLA-A and -B loci which were useful for distinguishing subtypes of HLA-A3 and -B44. Strictly specific bands were observed for HLA-A3, -A11, -B7, -B57. and -Cw4. Molecular identification of two HLA-A3 subtypes was possible by HLA-A RFLP and D6S265 PCR analyses. The two alleles of the I82 locus were associated with different HLA-A3 subtypes. It was shown that the serologically HLA-A3 homozygous cell line EHM was heterozygous for the two subtypes. The common subtype formed 91% of HLA-A3 antigens. Some serologically HLA-A3 homozygous healthy individuals were heterozygous for the subtypes. Using these new polymorphisms, a thorough molecular analysis of the haplotype HLA-A3B7DR15 at the three regions of the MHC was performed. The results have implications on HLA matching in transplantation, population genetics of the MHC, and disease association studies.

Base Sequence↗
PubMed1995

Class II MHC typing in pemphigoid gestationis.

Pemphigoid gestationis (PG) is a rare, autoimmune skin disease associated with pregnancy or the immediate post-partum period, previously shown to be associated with the HLA class II antigens DR3 and DR4. Advances in molecular analytical techniques now allow the identification of HLA alleles previously difficult to define by serological assays. Unsuspected polymorphism within the HLA-DR3 and DR4 classes can, therefore, be identified. The aim of our study was to apply these newer techniques to the question of genetic predisposition in PG by re-evaluating the association with DR3 and by studying a possible link with DQ. We have investigated by restriction fragment length polymorphism, the DQA, and by sequence specified oligonucleotide probing the DQB and DRB1 (HLA DR) specificities of 41 women with immunofluorescence-confirmed PG. The principal finding of this study is that there is an association between PG and DRB1*0301 (DR3) and DRB1*0401/040X (DR4). Although there is also an increase (P = 0.06) in the concurrent presence of both antigens, this appears to be due to the association with either antigen alone. We also found an increase in the frequency of DQA1*2 (P = 0.016 vs. control) and a decrease in frequency of DQB1*0201 (P = 0.022 vs. controls) and DQB1*0602 (P = 0.026 vs. controls).

Case-Control Studies↗
PubMed2006

Passive sexual transmission of human immunodeficiency virus type 1 variants and adaptation in new hosts.

Human immunodeficiency virus type 1 (HIV-1) genetic diversity is a major obstacle for the design of a successful vaccine. Certain viral polymorphisms encode human leukocyte antigen (HLA)-associated immune escape, potentially overcoming limited vaccine protection. Although transmission of immune escape variants has been reported, the overall extent to which this phenomenon occurs in populations and the degree to which it contributes to HIV-1 viral evolution are unknown. Selection on the HIV-1 env gene at transmission favors neutralization-sensitive variants, but it is not known to what degree selection acts on the internal HIV-1 proteins to restrict or enhance the transmission of immune escape variants. Studies have suggested that HLA class I may determine susceptibility to HIV-1 infection, but a definitive role for HLA at transmission remains unproven. Comparing populations of acute seroconverters and chronically infected patients, we found no evidence of selection acting to restrict transmission of HIV-1 variants. We found that statistical associations previously reported in chronic infection between viral polymorphisms and HLA class I alleles are not present in acute infection, suggesting that the majority of viral polymorphisms in these patients are the result of transmission rather than de novo adaptation. Using four episodes of HIV-1 transmission in which the donors and recipients were both sampled very close to the time of infection we found that, despite a transmission bottleneck, genetic variants of HIV-1 infection are transmitted in a frequency-dependent manner. As HIV-1 infections are seeded by unique donor-adapted viral variants, each episode is a highly individual antigenic challenge. Host-specific, idiosyncratic HIV-1 antigenic diversity will seriously tax the efficacy of immunization based on consensus sequences.

AIDS Vaccines↗
PubMed1999

Polymorphism in the regulatory regions of the HLA-DPB1 gene.

Nucleotide sequencing of approximately 400 basepairs upstream from exon 1 of the DPB1 gene and sequence specific oligonucleotide hybridisation identified eight nucleotide positions to be polymorphic which were in linkage disequilibrium (LD) with DPA1 and DPB1 alleles. Substitutions at two sites (-230 and -224) formed three genotypes (DP-PRO1-3). DP-PRO 1 was the most common genotype and was in LD with DPA1*0103, *0202 and DPB1*0401, *0501. DP-PRO 2 was observed in LD with DPB1*02012, *1601, *1701 and DPA1*0104. DP-PRO3 was in LD with DPB1*0901, *1001 and DPA1*0201. Electrophoretic Mobility Shift Assays (EMSA) performed with restriction enzyme fragments showed substitutions at -230 and -224 not to be involved in binding nuclear proteins. Six substitutions were found on a single genotype (DP-PRO4) which was observed in seven samples; 67% of DP-PRO4 inferred haplotypes were HLA-A2-B46, DRB1*0901, DQB1*03032, DPA1*0401, DPB1*1301. Three of the substitutions occurred in conserved regulatory region boxes, W', X and Y, and three in the signal and leader sequences. EMSA competitive binding assays performed with oligonucleotide probes for the substitutions showed no difference in binding affinity for W' and X probes. The DP-PRO4 Y box had a decreased nuclear protein binding affinity compared to DP-PRO1-3. Whether the sum of the differences in DP-PRO4 relate to a change in the cell surface expression of HLA-DP is yet to be determined.

Binding Sites↗