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PubMed2003

[The association of HLA-DRB1 allele polymorphism with the genetic susceptibility to liver cirrhosis due to hepatitis B virus].

OBJECTIVE: To assess the association of human leucocyte antigen (HLA)-DRB1 allele with the genetic susceptibility to cirrhosis due to hepatitis B virus(HBV). METHODS: One hundred and six patients with cirrhosis due to HBV in Hubei area were investigated for HLA-DRB1 gene by polymerase chain reaction-sequence specific primers technique. The results were compared with those from 108 normal healthy people. RESULTS: The frequency of HLA-DRB1*1201/1202 allele was 20.28% in patient group, which was significantly higher than the frequency (6.01%) in control group, the relative risk (RR) being 4.9878 (P<0.01). The frequency of HLA-DRB1*1501/1502 allele was decreased in patient group (patient 6.6%, control 16.67%, RR=0.3043, P<0.05), while the frequencies of other HLA-DRB1 alleles were not significantly different(P>0.05). CONCLUSION: HLA-DRB1*1201/1202 allele may be the susceptibility gene in patients with cirrhosis due to HBV in Hubei Han nationality; HLA-DRB1*1501/1502 allele is a resistant gene in patients with cirrhosis.

Adult↗
PubMed1996

Association of tumor necrosis factor microsatellite polymorphisms with HLA-DRB1*04-bearing haplotypes in rheumatoid arthritis patients.

OBJECTIVE: To investigate 1) tumor necrosis factor (TNF) microsatellite allele frequencies in rheumatoid arthritis (RA), and 2) associations between TNF microsatellites and RA-associated HLA specificities in order to build up extended HLA haplotypes. METHODS: Eighty-five caucasoid patients with RA and 109 healthy caucasoid controls were typed for TNF microsatellites a-d using fluorescent-labeled primers and semiautomated genotyping. A further 56 RA patients who were selected for having certain HLA-DRB1 types were also typed for these TNF microsatellites. Linkage disequilibria between TNF and HLA alleles were calculated, and extended haplotypes were established. RESULTS: The TNFa6 allele frequency was significantly increased in the RA patients compared with the controls (P = 0.0019, odds ratio [OR] 2.5, 95% confidence interval [95% CI] 1.3-4.6), an increase that was further evident in patients who were HLA-DRB1*0401 homozygous (P = 0.0003, OR 7.3, 95% CI 2.2-24.4). This increase was found to be due to association with HLA-DRB1*0401. No TNF microsatellite allele was found to be associated with HLA-DRB1*0404. Three HLA extended haplotypes were identified in the RA group: 1) HLA-DRB1*0401;TNFd4;TNFa6;TNFb5;HLA-B44; HLA-Cw5;HLA-A2, 2) HLA-DRB1*0301;TNFd2; TNFa2;TNFb3;HLA-B8;HLA-Cw7;HLA-A1, and 3) TNFd5;TNFc2;TNFa2;TNFb1;HLA-B62;HLA-Cw3. CONCLUSION: TNF microsatellites found to be associated with RA do not appear to be independent of class II HLA associations.

Alleles↗
PubMed2001

[Association between asthma and the polymorphism of HLA-DQ genes].

OBJECTIVE: To investigate association between asthma and HLA-DQ genes in Chinese asthma family. METHODS: HLA genotyping was done for HLA-DQ using polymerase chain reaction-sequence specific primers (PCR-SSP) in 98 members of 32 Chinese asthma families and 67 normal controls. RESULTS: The allele frequencies of DQA1 * 0101 and DQA1 * 0601 in asthmatics (40.0% and 45.0% respectively) were significantly higher than those in normal controls (16.4% and 13.4% respectively; chi(2) = 6.1860, P < 0.05, RR = 3.39 and chi(2) = 11.609 0, P < 0.01, RR = 5.27 respectively). The allele frequencies of DQB1 * 0303 and DQB1 * 0601 in asthmatics (55.0% and 47.5% respectively) were also significantly higher than those in normal controls (13.7% and 13.7% respectively; chi(2) = 15.740 0, P < 0.01, RR = 7.68 and chi(2) = 10.930 0, P < 0.01, RR = 5.69 respectively). The allele frequency of DQ * 0201 (39.4%) was significantly higher in members with positive specific IgE response to dermatophagoides than that in non-atopy members (12.0%) in asthma family (t = 2.382 5, P < 0.05). CONCLUSION: HLA-DQA1* 0101, DQA1 * 0601 and HLA-DQB1 * 0303, DQB1 * 0601 may be the susceptible alleles of asthma. HLA-DQB1 * 0201 allele may limit the specific IgE response to dermatophagoides.

Adolescent↗
PubMed2005

[Polymorphism of HLA-B* 40 gene family in Chinese Han population].

To investigate the allele distribution of HLA-B* 40 gene family in Chinese Han population and to study its influence on the selection of clinical transplantation donor, the HLA-B genetypes of 381 individuals randomly selected from Chinese National Marrow Donor Project were identified by PCR-SSO, and then all the HLA-B* 40 positive samples from the above population and the B* 40 homozygote samples received from another 1 270 registered donors were analyzed by PCR-SBT and PCR-SSP at high resolution. The results showed that the population of 381 registered donors was examined at HLA-B locus by using Hardy-Weinberg equilibrium, the gene frequency of HLA-B* 40 was 0.1692. Four different HLA-B* 40 alleles (B* 4001, B* 4002, B* 4003, B* 4006) were identified, and the serological specificity was B60 and B61 respectively. The relative frequency of each allele was 0.1192 for B* 4001, 0.0154 for B* 4002, 0.0038 for B* 4003, 0.0308 for B* 4006. The distribution of B* 40 homozygote revealed a certain regularity at high-resolution, B* 40XX (B* 4001 group), at low-resolution; B* 4001 at high resolution; B* 40XX (B* 4002 group), at low-resolution; B* 4002 or B* 4006 or heterozygote of both at high-resolution. It is concluded that in Chinese Han population, predominant allele in HLA-B* 40 gene family is B* 4001, the high-resolution typing may be recommended to use for the selection of clinical transplantation donor.

Alleles↗
PubMed1998

[Polymorphism of HLA-DQA1,-DQB1 genes in Uygur and Kazak ethnic groups and comprehensive analysis of 25 related populations].

HLA-DQA1 and -DQB1 genes were investigated in two Chinese minor natinalities, Uygur and Kazak using PCR-RFLP genotyping method. Of the 8 DQA1 alleles, DQA1 *0301 was the most common in Uygurs and Kazaks. DQA1 *0401 and *0601 were the rarest alleles in Uygurs and *0601 in Kazaks. Of the 16 DQB1 alleles tested, DQB1 *0201 and *0301 were the most frequent alleles in Uygurs and Kazaks. DQB1 *0502, *05032 and *0504 in Uygurs, *05032, *0504 and *0605 in Kazaks were absent. Neither DQA1 nor DQB1 difference was found between the two populations. From the phylogenetic tree based on the gene frequencies of HLA-DQA1 and -DQB1 in Uygur, Kazak and other 25 related ethnic groups, we suggest that Uygurs and Kazaks have a closer relationship, and they are closer to Mongoloid, not Caucasoid.

Adult↗
PubMed1980

Demonstration of structural polymorphism among HLA-DR light chains by two-dimensional gel electrophoresis.

Human HLA-DR antigens were immunoprecipitated from Nonidet P-40 extracts of [35S]methionine-labeled B lymphoblastoid cell lines and compared by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and isoelectric focusing (IEF). Two-dimensional (2-D) gel analyses, combining SDS-PAGE in the first dimension and IEF in the second dimension, revealed that the heavy (alpha) and light (beta) chains of each DRw specificity displays microheterogeneity of charge. However, the pattern of the heavy chain did not vary among different DRw specificities. In contrast, the light chains of different DRw types varied both in apparent size and charge distribution. Removal of sialic acids with neuraminidase or inhibition of glycosylation with tunicamycin reduced the microheterogeneity of both DR subunits. However, the heavy and light chains each still focused as two major bands, suggesting that other post-translational modifications contribute to the microheterogeneity or that there are two nonallelic DR-like molecules. After treatment with either neuraminidase or tunicamycin, the DR light chains, but not the heavy chains, were still structurally polymorphic. The DR light chains of serologically cross-reactive specificities displayed similar 2-D gel patterns suggesting that the structural polymorphism of the DR light chains is the basis for the serologically detected polymorphism of the HLA-DR antigens. Two additional polypeptides were observed in immunoprecipitates of DR antigens. These proteins, designated M1 and M2, both had a basic isoelectric point and were invariant among different cell lines. The protein M1 may be intracellular because it can not be immunoprecipitated from the cell surface.

Amino Acid Sequence↗
PubMedDate not supplied

Minor histocompatibility antigen HA-1 and HPA-5 polymorphisms in HLA-identical related bone marrow transplantation.

The minor histocompatibility antigens (mHags), HA-1 and HPA-5, are immunogenic alloantigens shown to be responsible for graft-versus-host disease (GVHD) in HLA-identical bone marrow transplantation. Both antigens have two known alleles each, resulting in a single amino acid polymorphism. The HA-1H allele encodes histidine, whereas the HA-1R allele encodes arginine. The HPA-5b (Br(a)) allele encodes lysine, whereas the HPA-5a (Br(b)) encodes glutamic acid. In this study, 49 bone marrow transplant recipients and their genetically related HLA-identical donors were evaluated for the presence of HA-1, whereas 39 recipients, different from the abovementioned ones, and their HLA-identical siblings were analyzed for the presence of HPA-5. The frequencies of the two alleles of HA-1 in the recipient population were HA-1R = 0.663 and HA-1H = 0.336. In the donor population, the respective frequencies were 0.704 and 0.296. Seven donors (14.5%) were mismatched with the recipients for HA-1H. In contrast, the frequencies of the two alleles of HPA-5 in the recipient population were HPA-5a = 0.859 and HPA-5b = 0.141; whereas, among donors, they were 0.820 and 0.180, respectively. Five donors (12.8%) were found to be mismatched with their recipients for HPA-5. These results provide insight into the polymorphism of mH antigens based on the study of their frequencies in bone marrow transplant recipients and their genetically HLA-identical siblings, an endeavor that is essential to investigate the presence of HA-1 and HPA-5 mHags.

Antigens, Human Platelet↗
PubMed1996

Polymorphism of HLA-DRB, -DQA1, and -DQB1 in rheumatoid arthritis in Asian Indians: association with DRB1*0405 and DRB1*1001.

We investigated the DRB, DQA1, and DQB 1 polymorphism and haplotypes in sporadic and familial RA subjects of Asian Indian origin by PCR oligotyping using biotinylated SSOPs. Molecular subtyping of DRB 1*04 in RA patients showed strongest association with highest relative risk with DRB 1*0405, followed by DRBI*0401. A significant decreased frequency of DRBI*1502 was observed in patients compared to controls (chi 2 = 4.5). Among other alleles, DRBI*1001 was found to be significantly increased. A total of 73.3% of patients carried the shared sequence of the third HVR (67-74) of DRB1 domain compared to its presence in only 37.6% of controls. A significant number of patients carried DR4 haplotypes on DQBI*0302 (58%) as against DQBI*0301 which was present only on 10.5% of the haplotypes. When compared to controls, the difference was significant for the latter allele only. Few unique DRDQ haplotypes were observed in Asian Indians. Among DR-DQ haplotypes, DRB1*0401-DQB1*0302 gave the highest risk whereas DRB1*0403-DQB1*O301 was negatively associated. Alleles with negative charge at position 70 confer protection or are negatively associated with RA whereas among the associated alleles, glycine at position 86 resulted in higher risk than those with valine at this position. A heterogenous association of DQB1 alleles with DR4 subtypes, influencing susceptibility to RA, suggests the DQB locus is not primarily associated with RA and susceptibility lies in the sequence 67-74 of the DRB1 loci.

Alleles↗
PubMed1997

Molecular genetic studies on DNA polymorphism of the HLA class II genes associated with human longevity.

Okinawan Japanese are well known for their longevity; the population rate of centenarians in Okinawa is about 3.8 times higher than that of the whole Japan, where the average life expectancies both among men and among women are the highest in the world. In this study, we analyzed HLA class II alleles of Okinawan centenarians by the polymerase chain reaction-restriction fragment-length polymorphism (PCR-RFLP) method for the purpose of clarifying the presence of primary genetic factors in the major histocompatibility complex (MHC) region associated with human longevity. DRB1*1401, DQB1*0503, DQA1*0101=0104 and DQA1*05 were significantly increased in the centenarians. The significant increase of HLA-DQB1*0503 and/or DQA1*0101=0104 in the centenarians can be explained by a linkage disequilibrium with DRB1*1401, or vice versa. Further, the tendency was observed toward increase with respect to DRB1*0101 and DRB1*1201. These data suggest that several alleles of the HLA-DRB1 and/or HLA-DQ genes are involved in human longevity.

Adult↗
PubMed1997

The nature of polymorphism of the HLA class I non-coding regions and their contribution to the diversification of HLA.

The sequence database of HLA class I genes is mainly derived from mRNA analysis. Little is known about the non-coding sequences of the different class I alleles. In this study we have determined the sequence of the 1st through 3rd introns of the majority of HLA-A and -B alleles. The few published sequences emerged to contain substantial errors. The introns turned out to be highly polymorphic with a variability of 14.6% in the 1st intron decreasing to 6.2% in the 3rd intron. Against all expectations, this variability is not characterised by random point mutations but by a highly systematic diversity reflecting the ancestral relationship of the HLA alleles. The variability is arrested on the level of the serological diversity. The striking conservation within each ancestral lineage suggests that point mutations have been negatively selected. This finding could be explained by the evolutionary pressure on base order, promoting the potential to extrude single-strand stem-loops from supercoiled duplex DNA, which is believed to be important for combination. Moreover, the GC content was found to be as high as 78% in the 1st and 2nd introns and 55% in the 3rd intron. These CpG islands are directly involved in the exchange of short stretches of DNA in unequal crossing-over events. Additionally, conversion between different class I sequences is facilitated by regions of strong homology, stabilizing the pairing of variable regions. All these observations indicate the potential of a substantial contribution of introns to the recombinational activity of class I genes. The exclusive clustering of CpG islands in the 1st and 2nd introns restricts the gene conversion events to the regions of the 2nd and 3rd exons and therefore protects the conservation of the 5 flanking region and the 3 part of the gene. Since there are less diversification forces acting on introns they may be more conserved in a trans-species manner than exons. Therefore, they could provide the answer for the controversy regarding intra- or trans-species evolution.

Alleles↗
PubMed1997

Application of HLA class II polymorphism analysis to the study of the population structure of the Island of Krk, Croatia.

The population structure of the northern Adriatic island of Krk, Croatia, was studied using PCR methodology and nonradioactive oligonucleotide hybridization for the analysis of HLA-DRB1, DRB3, DRB4, DRB5, DQA1, and DQB1 polymorphisms. Allele frequencies, genetic kinship (R), and genetic distances (E2) were computed, and correlations between distance (genetic, linguistic, geographic) and kinship (migration) matrices were examined. The results, reflecting past (micro-) evolutionary processes, indicate that ethnohistorical and sociocultural events rather than geographic distances are the primary determinants of today's population structure of the island.

Adult↗
PubMed1998

Influence of the HLA class II polymorphism in chronic Chagas' disease.

Chagas' disease or American trypanosomiasis due to Trypanosoma cruzi has existed at least since the time of the Inca empire and contributes significantly to cardiovascular morbidity and mortality in several countries of this continent. Due to the fundamental role of human class II molecules polymorphic residues in the control of the immune response, a study was designed to define by DNA typing HLA class II alleles in a sample of 67 serologically positive individuals with and without cardiomyopathy and in 156 healthy controls of similar ethnic origin. Genomic DNA extraction, PCR amplification of the HLA-DRB1 and DQB1 second exon regions and hybridization to labelled specific probes were carried out following the 11th International Histocompatibility Workshop reference protocol. Comparison of DRB1 and DQB1 allele frequencies among the patients and control subjects showed a decreased frequency of DRB1*14 and DQB1*0303 in the patients, suggesting independent protective effects to the chronic infection in this population. Allele frequencies comparison between patients with and without cardiomyopathy showed a higher frequency of DRB1*01, DRB1*08 and DQB1*0501 and a decreased frequency of DRB1*1501 in the patients with arrhythmia and congestive heart failure. The results suggest that HLA Class II genes may be associated with the development of a chronic infection and with heart damage in Chagas' disease.

Adult↗
PubMed1998

HLA-DQA1, -DQB1 polymorphism distribution in Chinese women with pregnancy induced hypertension in Shanghai area.

OBJECTIVE: To explore the association of human leukocyte antigen (HLA) with pregnancy induced hypertension (PIH). METHODS: We oligotyped HLA-DQA1, -DQB1 locus of 30 Chinese PIH families and 14 control families in Shanghai area by polymerase chain reaction-sequence specific oligonucleotide (PCR-SSO) hybridization method (probes labeled by nonradioactive technique). RESULTS: Compared with the control group, the allelic frequency of HLA-DQB1 * 0502 was significantly higher in PIH couples, and the sharing of HLA-DQA1 increased in PIH couples as well. No difference was found in HLA-DQA1 allelic frequencies or HLA-DQB1 sharing between the two groups. Analysis of neither HLA-DQA1 nor HLA-DQB1 allelic frequencies in PIH patients and PIH mother-and-fetuses showed positive result. CONCLUSION: HLA-DQB1 * 0502 may be a marker of susceptibility to PIH. DQB1 * 0502 itself or some gene(s) located in HLA class II region and in linkage disequilibrium with 0502 affect maternal T cell immunity during pregnancy. The increase of compatibility in HLA-D region causes the production of blocking antibody to decrease.

Adult↗
PubMed1990

HLA class I gene polymorphism in genetic hemochromatosis.

The authors have studied HLA class I polymorphism in an attempt to identify a genomic marker of the hemochromatosis gene. Five enzymes were used (HindIII, EcoRI, EcoRV, PvuII, and HincII) in 47-106 unrelated patients and 71-91 controls. Both populations were HLA-typed. The relationship between the restriction fragments and HLA-A antigens was considered. Comparison of the two groups revealed a significantly high frequency of one 14 kb EcoRI fragment among the HLA-A3 hemochromatosis patients. The fragment hybridizes to an HLA-A specific probe but not to an HLA-B specific probe, and is associated with the hemochromatosis gene, which is itself associated with HLA-A3.

HLA Antigens↗
PubMed1992

HLA and immunoglobulin polymorphisms in idiopathic dilated cardiomyopathy.

Dilated cardiomyopathy (DCM) is an idiopathic heart muscle disorder. The presence of circulating cardiac antibodies and the association with HLA-DR4 are consistent with autoimmune pathogenesis in a subset of patients. Sixty-eight DCM patients and 277 controls were typed for IgG heavy-chain constant region (Gm) and kappa light-chain (Km) allotypes. All patients and 210 of the 277 controls were HLA-DR typed. The Gm (1, 3, 17; 23; 5*, 21, 28) phenotype was overrepresented in DCM compared with controls (25% vs 13%, p = 0.0139, pc = NS, RR = 2.23). The frequency of this phenotype was higher in patients with younger age at onset, shorter symptom duration, and among those who were positive for cardiac as well as for non-organ-specific autoantibodies than in controls. A higher frequency of the Gm (1, +/- 2, 3, 17; +/- 23; 5*, 21, 28) heterozygous phenotypes was also found in DCM compared to controls (40.91% vs 26.89%; p = 0.02, pc = 0.04, RR = 1.88). The finding of Gm heterozygosity in DCM was associated with serum positivity for cardiac antibodies. A higher proportion of DCM patients were positive for both the Gm (1, 3, 17; 23; 5*, 21, 28) phenotype and HLA-DR4 compared to normals (3/68 vs 0/210; p = 0.04, RR = 22.50).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1999

[HLA-DRB alleles polymorphism in Han, Hui, Uygur and Tibetan populations in northwestern China].

According to the 11th THW standard, we designed a pair of primers by which a segment of 256bp of HLA-DRB1, B3, B4, and B5 could be amplified simultaneously. Twenty-seven oligonucleotide probes were designed and synthesized for 39 loci on DRB1, 3 on DRB3, 1 on DRB4 and 3 on DRB5. A PCR-SSO DNA typing protocol was built, which met the standard of HLA class II DNA typing in 11th IHW. With this method, 186 of Chinese (Han) in Xi'an, 169 of Hui in Ningxia, 200 of Uygur in Xinjiang, and 188 of Tibetan in Tibet were detected with a comparison study. The genetic distribution of 46 loci of DRB in four ethnic healthy populations were surveyed. No diversity has been found between Han and Hui in DRB. DRB1 * 02(16.9%), DRB1 * 07 (13.1%), and DRB1 * 09(12.0%) were the higher frequent loci in Han. More DRB loci were detected in Tibetan but without higher loci as in Han and Hui. The DRB polymorphism of Uygur population was similar to Caucasian. A discriminative highest frequency of DRB1 * 07(23.8%) was found in Uygur, which implied a selection happened.

Alleles↗
PubMed2005

Role of the CCL2/MCP-1 -2518A>G gene polymorphism in HLA-B27 associated uveitis.

PURPOSE: Acute anterior uveitis (AAU) is the most common form of uveitis. Up to 50% of patients with AAU are HLA-B27 positive. Since HLA B27 itself plays only a minor role in the overall genetic background, other genetic variants are likely to contribute to the susceptibility to AAU. The chemokine (C-C motif) ligand 2 (CCL2) gene, coding for monocyte chemoattractant protein-1 (MCP-1), a chemotactic cytokine, is involved in the induction of uveitis. A CCL2 gene polymorphism, which is characterized by an A>G substitution at nucleotide -2518 in the promoter region of CCL2 has been previously shown to affect MCP-1 synthesis. The purpose of the present study was to investigate a hypothesized association between this genetic variant and the presence of HLA-B27 associated AAU. METHODS: The study group comprised 114 patients with HLA-B27 associated AAU. One hundred and eleven healthy HLA-B27 positive individuals served as the HLA-B27 positive control group, whereas 81 healthy HLA-B27 negative individuals served as a HLA-B27 negative control group. Genotyping for the CCL2 -2518A>G polymorphism was performed by polymerase chain reaction. RESULTS: Carriers of a CCL2 -2518G allele were found significantly more often in patients with HLA-B27 associated AAU than among HLA-B27 positive controls (49.2% and 31.5%, respectively; odds ratio 2.1; 95% confidence interval 1.2-3.6; p=0.007). CONCLUSIONS: Our data suggest that the CCL2 -2518A>G polymorphism may play a role in HLA-B27 associated acute anterior uveitis.

Acute Disease↗