Sex-specific analysis in Behçet's disease reveals higher genetic risk in male patients.

OBJECTIVES: Behçet's disease tends to be more severe in men than women. This study was undertaken to investigate sex-specific genetic effects in Behçet's disease. METHODS: A total of 1762 male and 1216 female patients with Behçet's disease from six diverse populations were studied, with the majority of patients of Turkish origin. Genotyping was performed using an Infinium ImmunoArray-24 BeadChip, or extracted from available genotyping data. Following imputation and extensive quality control measures, genome-wide association analysis was performed comparing male to female patients in the Turkish cohort, followed by a meta-analysis of significant results in all six populations. In addition, a weighted genetic risk score for Behçet's disease was calculated and compared between male and female patients. RESULTS: Genetic association analysis comparing male to female patients with Behçet's disease from Turkey revealed an association with male sex in HLA-B/MICA within the HLA region with a GWAS level of significance (rs2848712, OR = 1.46, P = 1.22 × 10-8). Meta-analysis of the effect in rs2848712 across six populations confirmed these results. Genetic risk score for Behçet's disease was significantly higher in male compared to female patients from Turkey. Higher genetic risk for Behçet's disease was observed in male patients in HLA-B/MICA (rs116799036, OR = 1.45, P = 1.95 × 10-8), HLA-C (rs12525170, OR = 1.46, P = 5.66 × 10-7), and KLRC4 (rs2617170, OR = 1.20, P = 0.019). In contrast, IFNGR1 (rs4896243, OR = 0.86, P = 0.011) was shown to confer higher genetic risk in female patients. CONCLUSIONS: Male patients with Behçet's disease are characterized by higher genetic risk compared to female patients. This genetic difference, primarily derived from our Turkish cohort, is largely explained by risk within the HLA region. These data suggest that genetic factors might contribute to differences in disease presentation between men and women with Behçet's disease.

HLA Association among Thai Patients with Diffuse and Limited Cutaneous Systemic Sclerosis.

This study aimed to clarify the association of HLA Class I and II with dcSSc and lcSSc in Thais. HLA typing for 11 gene loci (Class I: HLA-A, B and C, and Class II [HLA-DR, DP and DQ]) was carried out using the Next Generation DNA Sequencing method (three fields) in 92 Thai patients with systemic sclerosis (55 dcSSc, 37 lcSSc) and 135 healthy controls (HCs). The distribution of HLA alleles in patients with dcSSc and lcSSc was compared. When compared with HCs, the AF of A*24:02:01, A*24:07:01, B*27:04:01 and B*27:06 showed an increasing trend in lcSSc patients without statistical significance. DRB1*15:02:01, DRB5*01:02:01, DQA1*01:01:01, DQB1*05:01:24, DPA1*02:01:01 and DPB1*13:01:01 increased significantly in dcSSc patients. DQB1*05:01:24 and DPB1*13:01:01 also increased significantly in lcSSc patients, but less significantly than in dcSSc patients. The association of DPB1*05:01:01 with lcSSc was significantly protective. HLA-A*24:02:01, B*27:06 and C*03:04:01 formed a three-locus haplotype that also constituted an eight-locus haplotype with DRB1*15:02:01, DQA1*01:01:01, DQB1*05:01:24, DPA1*02:01:01 and DPB1*13:01:01. There was a possibility that HLA Class I would play a role in the pathogenesis of lcSSc, while Class II played more of a role in the dcSSc in Thai patients.

Association of HLA-DRB1*15:02 and DRB5*01:02 allele with the susceptibility to systemic sclerosis in Thai patients.

A genetic study, particularly in HLA-DRs, has never been performed in Thai patients with systemic sclerosis (SSc). This study was performed to investigate the association between the HLA-DR series in Thai SSc patients. HLA-DR subtypes were determined in 50 Thai SSc patients and 99 healthy controls (HCs). All SSc patients met the ACR classification criteria for SSc. HLA-DR typing was performed using INNO-LiPA HLA-DRB Decoder kits (INNOGENETICS) and reconfirmed using MICRO SSP HLA DNA Typing kits (ONE LAMBDA). The allele frequency (AF) of HLA-DR*15, compared with HC, was significantly higher in all SSc patients (41.0 vs 21.7%, Pc = 0.0083) and SSc patients with anti-Scl70 antibody positive (anti-Scl70+) (47.1%, Pc = 0.0018). Among the HLA-DR*15 alleles, the AF of the DRB1*15:02 was increased significantly in all SSc patients (29.0 vs 12.6%, Pc = 0.0219) and SSc patients with anti-Scl70+ (32.4 vs 12.6%, Pc = 0.0196). The AF of the HLA-DRB5*01:02 allele was also increased in all SSc patients (27.0 vs 12.6%, Pc = 0.0166) and in SSc patients with anti-Scl70+ (29.4%, Pc = 0.0124). The AF of the DR*04 was significantly lower in the SSc patients (1.0 vs 9.6%, Pc = 0.0399). However, the AF of the DRB1*15:02 and DRB5*01:02 was not different among SSc patients with or without clinical manifestations (pulmonary fibrosis, digital pitting scar, sclerodactyly, myositis, and sicca symptoms). In addition, there was no significant association between clinical manifestations among individuals who carried HLA-DRB1*15:02 or DRB5*01:02. HLA-DRB1*15:02 and DRB5*01:02 alleles were significantly elevated in Thai SSc patients, especially in those with anti-Scl70+. The HLA-DRB1*04 was a protective allele against Thai SSc patients.

Association of HLA-DRB1*15:02:01, DQB1*05:01:24 and DPB1*13:01:01 in Thai patients with systemic sclerosis.

HLA studies in patients with systemic sclerosis (SSc) have shown variable results. This study aimed to examine the association of HLA class I and II risk alleles in Thai SSc patients, and clarify the contribution of risk HLA alleles to the pathogenesis and clinical manifestations. Blood samples from 92 SSc patients and 135 healthy controls (HCs) were collected. Eleven loci of the HLA class I (HLA-A, B, and C) and class II (HLA-DR, DP, and DQ) genes were determined by a 3-field (6-digit) analysis using the Next Generation DNA Sequencing (NGS) method. Anti-topoisomerase-I antibodies (ATA) and anti-centromere antibodies (ACA) were identified by ELISA methods. Allele frequencies (AFs) of HLA-DRB1*15:02:01, DRB5*01:02:01, DQB1*05:01:24, DPB1*13:01:01, and DQA1*01:01:01 were increased significantly in the whole SSc and SSc patients with positive ATA, but with negative ACA (SSc/ATA+/ACA-). Of these, DPB1*13:01:01 was the most susceptible allele. The DRB1*15:02:01, DQB1:05:01:24, and DPB1*13:01:01 alleles were estimated to locate on the unique haplotype, and haplotype frequency was estimated to be significantly higher than those in the HCs (p = 0.002). The linkage analysis of DRB1*15/16 revealed that most of the DRB1*15:02:01 alleles were linked to DRB5*01:02:01 or DRB5*01:08:01N. The linkage of DRB1*16:02:01 to DRB5*01:01:01 was observed frequently. The associations of risk alleles with several SSc clinical features were observed. HLA-DRB1*15:02:01, DRB5*01:02:01, DQB1*05:01:24, and DPB1*13:01:01 on the unique haplotype were associated with the pathogenesis and clinical features of SSc in Thai patients. The linkage of DRB1*15:02:01 to DRB5*01:08:01N was observed commonly in northern Thai patients.

Determination of T Cell Responses in Thai Systemic Sclerosis Patients.

Objectives: This study is aimed at determining the role of T cells by assessing the numbers of IFN-γ- and IL-2-secreting T cells following stimulation with peptides derived from DNA topoisomerase-I protein in Thai SSc patients. Methods: Fifty Thai SSc patients and 50 healthy controls (HC) joined this study. IFN-γ and IL-2 levels upon stimulation of T cells with 6 peptides derived from DNA topoisomerase-I protein were determined. Anti-nuclear antibodies (ANA) and anti-Scl-70 antibodies were determined by using the ELISA method. Results: In SSc patients, we detected a significantly higher number of IFN-γ- and IL-2-secreting CD8+ T cells than IFN-γ- and IL-2-secreting CD4+ T cells after stimulation with pooled peptides derived from DNA topoisomerase-I protein. A similar percentage of CD4+IL-2+, CD4+IFN-γ +, and CD8+IL-2+ were detected following stimulation with DNA topoisomerase-I protein -in SSc patients with anti-Scl-70 antibody (SSc/anti-Scl-70+) and those without. In contrast, the amount of CD8+IFN-γ + cells was significantly higher in SSc/anti-Scl-70+ than those without. Stimulation with individual peptides showed that CSLRVEHINLHPELD (sPep3; 15 amino acids; position 505-519 of DNA topoisomerase-I protein) was the optimal epitope that induced T cells secreting the highest levels of IFN-γ and IL-2. A higher percentage of IFN-γ +CD4+ T cells was detected in SSc/anti-Scl-70+ than those without the following stimulation with peptides 2 (amino acid position 475-486 [RAVALYFIDKLA] of protein DNA topoisomerase). Conclusion: The results from this study emphasize the critical role of DNA topoisomerase-I peptides on the activation of T cells in SSc patients. The findings provide a better understanding of SSc's immunopathogenesis and may lead to the development of diagnostic tools and specific treatments for SSc in the future.

The diagnostic utilities of anti-agalactosyl IgG antibodies, anti-cyclic citrullinated peptide antibodies, and rheumatoid factors in rheumatoid arthritis.

The purpose of this study was to investigate the diagnostic utilities of anti-agalactosyl IgG antibody (CARF), anti-cyclic citrullinated peptide (CCP) antibody and rheumatoid factor (RF) in rheumatoid arthritis (RA), non-RA rheumatic diseases, and chronic viral hepatitis. The authors determined serum levels of CARF and anti-CCP2 by ELISA and IgM-RF by a immunonephelometric method in 834 controls and in 397 patients with the following conditions: RA (100), non-RA rheumatic diseases [systemic lupus erythematosus (SLE) 30, primary Sjogren's syndrome 18, systemic sclerosis 30, inflammatory myositis 19], chronic viral hepatitis B and C (HBV 100, HCV 100). The sensitivities of CARF (83%) and anti-CCP (85%) were significantly higher than that of RF (75%, p = 0.01, respectively) in RA, and the specificity of anti-CCP (98%) was significantly higher than those of CARF (92%) and RF (90%, p < 0.001, respectively). A comparison of receiver operating characteristic (ROC) curves revealed that the diagnostic accuracies of CARF and anti-CCP were superior to that of RF (CARF vs. RF, p = 0.008, anti-CCP vs. RF, p = 0.017) in RA. CARF positivity was significantly higher than those of anti-CCP (p = 0.007) and RF (p = 0.008) in systemic sclerosis, and the positivity of CARF was significantly higher than that of anti-CCP in Sjogren's syndrome (p = 0.016). Furthermore, CARF had significantly higher positivity than anti-CCP or RF in chronic viral hepatitis B and C. Finally, the titers of these three markers in RA were significantly higher than in non-RA rheumatic diseases and in chronic viral hepatitis B and C. Our results suggest that anti-CCP is the most useful serologic marker for the differentiation of RA and non-RA rheumatic diseases, and chronic viral hepatitis B and C.

CTLA-4 polymorphisms in Thai patients with rheumatoid arthritis, systemic lupus erythematosus, and systemic sclerosis.

AIMS: Studies on polymorphisms of the cytotoxic T lymphocytes associated antigen-4 (CTLA-4) genes in rheumatic disease patients are limited in Southeast Asia. This pilot study aimed to determine CTLA-4 polymorphisms in Thai patients with rheumatoid arthritis (RA), systemic lupus erythematosus (SLE) and systemic sclerosis (SSc), and correlate them with serology. METHOD: One-hundred RA, 70 SLE and 50 SSc patients, and 99 healthy controls (HCs) were included in this study. Polymorphisms of the CTLA-4 gene at +49A/G, -318C/T, -1661A/G and -1722T/C loci were determined by polymerase chain reaction restriction fragment length polymorphism methods. Patient serum samples were determined as follows: RA (rheumatoid factor [RF] and anticyclic citrullinated peptide [anti-CCP]), SLE (antinuclear antibodies [ANA], anti-double-stranded DNA [anti-dsDNA], anti-Smith [anti-Sm], anti-ribonucleoprotein [anti-RNP], and anti-Sjögren's syndrome antigen A [SSA]), and SSc (ANA, anti-RNP, anti-SSA, anti-topoisomerase-1 [anti-Scl70], and anti-centromere antibodies [ACA]). RESULTS: Among the 4 loci studied (+49A/G, -318C/T, -1661A/G and -1722T/C) only the A allele frequency at the +49A/G was significantly higher in the RA patients than their HCs (47.25% vs 35.86%, P = .029, odds ratio [OR] 1.60; 95% CI 1.04-2.47). It also was significantly higher in the subgroup of RA patients with positive RF and anti-CCP than their HCs (47.50% vs 35.86%, P = .020, OR 1.62; 95% CI 1.06-2.47 and 48.89% vs 35.86%, P = .012, OR 1.71; 95% CI 1.11-2.64, respectively). No polymorphisms at these 4 loci were observed in SLE or SSc patients. CONCLUSION: The A allele at +49A/G locus of the CTLA-4 gene was associated with RA in Thais.

Genetic Association of a Gain-of-Function IFNGR1 Polymorphism and the Intergenic Region LNCAROD/DKK1 With Behçet's Disease.

OBJECTIVE: Behçet's disease is a complex systemic inflammatory vasculitis of incompletely understood etiology. This study was undertaken to investigate genetic associations with Behçet's disease in a diverse multiethnic population. METHODS: A total of 9,444 patients and controls from 7 different populations were included in this study. Genotyping was performed using an Infinium ImmunoArray-24 v.1.0 or v.2.0 BeadChip. Analysis of expression data from stimulated monocytes, and epigenetic and chromatin interaction analyses were performed. RESULTS: We identified 2 novel genetic susceptibility loci for Behçet's disease, including a risk locus in IFNGR1 (rs4896243) (odds ratio [OR] 1.25; P = 2.42 × 10-9 ) and within the intergenic region LNCAROD/DKK1 (rs1660760) (OR 0.78; P = 2.75 × 10-8 ). The risk variants in IFNGR1 significantly increased IFNGR1 messenger RNA expression in lipopolysaccharide-stimulated monocytes. In addition, our results replicated the association (P < 5 × 10-8 ) of 6 previously identified susceptibility loci in Behçet's disease: IL10, IL23R, IL12A-AS1, CCR3, ADO, and LACC1, reinforcing the notion that these loci are strong genetic factors in Behçet's disease shared across ancestries. We also identified >30 genetic susceptibility loci with a suggestive level of association (P < 5 × 10-5 ), which will require replication. Finally, functional annotation of genetic susceptibility loci in Behçet's disease revealed their possible regulatory roles and suggested potential causal genes and molecular mechanisms that could be further investigated. CONCLUSION: We performed the largest genetic association study in Behçet's disease to date. Our findings reveal novel putative functional variants associated with the disease and replicate and extend the genetic associations in other loci across multiple ancestries.

Genetic association of HLA-A*2601 with ocular Behçet's disease in Japanese patients.

OBJECTIVES: Behçet's disease (BD) is known to be associated with HLA-B*51, especially HLA-B*5101, in many different ethnic groups. Recently, several HLA-A or -B alleles have been proposed as possible candidate genes for BD in addition to HLA-B*5101. To investigate those associations, we studied HLA-A and -B alleles in Japanese ocular BD patients and the association of possible susceptibility HLA genes with visual prognosis. METHODS: Eighty-eight Japanese BD patients with uveitis and 104 healthy controls were enrolled for analyses of HLA-A and B alleles. Statistical analysis was performed with Fisher's exact test and odds ratio (OR). Association of the possible susceptible HLA gene and visual prognosis was also examined. RESULTS: The phenotype frequency (PF) of HLA-A*2601 was significantly higher in the patients (37.5%) than the controls (14.4%) (pc=0.00529, OR=3.56), especially in patients without HLA-B*5101 (57.4% vs. 14.1%, pc=4.58x10-6, OR=8.21). In contrast, the PF of HLA-A*2601 was not increased in patients with HLA-B*5101 (14.6% vs. 15.8%). Also, the PF in patients possessing HLA-A*2601 or HLAB* 5101 was increased up to 77.3%. Interestingly, the PF of HLA-A*2601 was significantly associated with poor visual prognosis corresponding to visual acuity of 0.1 or less in the worse eye (p=0.0262). CONCLUSIONS: Our results indicate that HLA-A*2601 is possibly associated with ocular BD, independent of HLAB* 5101, indicating that HLA-A*2601 is an additional susceptibility allele candidate of ocular BD in Japan. HLAA* 2601 would also be a possible marker for poor visual prognosis.

Contribution of HLA-B*51:01 and -A*26:01 to Behçet's disease and their clinical association in Thai patients.

AIMS: To investigate susceptible human leukocyte antigen (HLA) alleles and their associations with clinical features in Thai patients with Behçet's disease (BD). METHOD: Eighteen HLA-A and 36 HLA-B alleles were determined in 42 Thai BD patients and 99 healthy controls (HCs) by reverse line blot assay, and reconfirmed by MICRO SSP assay. RESULTS: The BD patients had significantly higher allele frequency (AF) of HLA-B*51 than the HCs (13.10% vs 5.05%, P = .025). The AF of HLA-A*26, -A*26:01 and -B*51:01 also was higher and almost reached statistical significance (5.59% vs 1.52%, P = .054, 5.95% vs 1.52%, P = .054 and 10.71% vs 4.04%, P = .051, respectively). However, the BD patients had significantly higher AF of either HLA-A*26:01 or -B*51:01 (16.67% vs 5.56%, P = .005), or -A*26:01 or -B*51X (19.05% vs 6.56%, P = .003). The AF of HLA-B*51:01 and -B*51X increased significantly in -A*26:01 non-carrier BD patients (12.16% vs 4.17%, P = .024 and 14.86% vs 5.21%, P = .019, respectively); and that of HLA-A*26:01 was significantly higher in -B*51X non-carrier BD patients (7.58% vs 1.67%, P = .034). HLA-B*51:01 associated significantly with the presence of posterior uveitis and visual impairment (18.18% vs 2.50%, P = .031 for both conditions). HLA-B*51:01 was not observed in BD patients with gastrointestinal involvement or arthritis. Furthermore, the AF of HLA-B*51:01 was significantly higher in HLA-A*26:01 non-carrier BD patients without arthritis (17.30% vs 0%, P = .050). CONCLUSION: HLA-B*51:01 was a susceptible allele for Thai BD patients, and associated with posterior uveitis and visual impairment. HLA-A*26:01 was another susceptible allele in HLA-B*51X non-carrier patients. The protective effect of HLA-B*51:01 on arthritis needs further investigation.

Myeloperoxidase antineutrophil cytoplasmic antibody-associated vasculitis with diffuse tubulointerstitial nephritis.

Renal involvement in antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis is characterized by focal segmental crescentic and/or necrotizing glomerulonephritis. Here, we report the case of a 66-year-old woman showing myeloperoxidase (MPO)-ANCA positivity and mononeuritis multiplex whose kidney biopsy revealed severe and diffuse tubulointerstitial nephritis despite the fact that crescentic necrotizing glomerulonephritis was focal. The mechanism of tubulointerstitial injury in ANCA-associated vasculitis remains unclear. Further studies are necessary to confirm the relationship between diffuse tubulointerstitial nephritis and ANCA-associated vasculitis.

Interactions of HLA-DR and Topoisomerase I Epitope Modulated Genetic Risk for Systemic Sclerosis.

The association of systemic sclerosis with anti-Topoisomerase 1 antibody (ATASSc) with specific alleles of human leukocyte antigen (HLA)-DR has been observed among various ethnics. The anti-Topoisomerase 1 antibody is a common autoantibody in SSc with diffuse cutaneous scleroderma, which is one of the clinical subtypes of SSc. On the other hand, an immunodominant peptide of topoisomerase 1 (Top1) self-protein (residues 349-368) was reported to have strong association with ATASSc. In this study, molecular dynamics simulation was performed on the complexes of Top1 peptide with various HLA-DR subtypes divided into ATASSc-associated alleles (HLA-DRB1*08:02, HLA-DRB1*11:01 and HLA-DRB1*11:04), suspected allele (HLA-DRB5*01:02), and non-associated allele (HLA-DRB1*01:01). The unique interaction for each system was compared to the others in terms of dynamical behaviors, binding free energies and solvation effects. Our results showed that three HLA-DR/Top1 complexes of ATASSc association mostly exhibited high protein stability and increased binding efficiency without solvent interruption, in contrast to non-association. The suspected case (HLA-DRB5*01:02) binds Top1 as strongly as the ATASSc association case, which implied a highly possible risk for ATASSc development. This finding might support ATASSc development mechanism leading to a guideline for the treatment and avoidance of pathogens like Top1 self-peptide risk for ATASSc.

Lymphocyte proliferation induced by high-affinity peptides for HLA-B*51:01 in Behçet's uveitis.

Several proteins have been proposed as candidate auto-antigens in the pathogenesis of Behçet's disease (BD). In this study, we aimed to confirm the cellular responses to candidate peptide autoantigens with high affinity for the HLA-B*51:01 molecule using computerized binding predictions and molecular dynamics simulations. We identified two new candidate peptides (HSP65PD, derived from heat shock protein-65, and B51PD, derived from HLA-B*51:01) with high-affinity to the HLA-B*51:01 binding pocket using the Immune Epitope Database for Major Histocompatibility Complex-I Binding Prediction and molecular dynamics simulations. The peptide-induced proliferation of lymphocytes from patients with BD, sarcoidosis, Vogt-Koyanagi-Harada disease (VKH) with panuveitis, systemic scleroderma (SSc) without uveitis, and healthy controls (HC) was investigated using the bromodeoxyuridine assay. The proliferative response of leukocytes to HSP65PD was significantly higher in BD (SI 1.92 ± 0.65) than that in sarcoidosis (SI 1.38 ± 0.46), VKH (SI 1.40 ± 0.33), SSc (SI 1.32 ± 0.31), and HC (SI 1.27 ± 0.28) (P = 0.0004, P = 0.0007, P < 0.0001, P < 0.0001, respectively, Mann-Whitney's U-test). The proliferative response of leukocytes to B51PD was also higher in BD than that in sarcoidosis, VKH, SSc without uveitis, and HC, whereas no significant differences were observed among the five groups in response to a control peptide derived from topoisomerase 1. A significantly higher response to HPS65PD and B51PD was observed in the HLA-B*51:01-positive patients with BD than in the HLA-B*51:01-negative patients. In conclusion, two peptides that had high affinity to HLA-B*51:01 in computerized binding prediction showed significantly higher response in HLA-B*51:01-positive patients with BD, indicating the usefulness of computerized simulations for identifying autoreactive peptides to HLAs.

Markedly different clinical features in 2 diabetes mellitus patients with extremely high tissue levels of the mitochondrial DNA A3243G mutation.

BACKGROUND: Mitochondrial DNA (mtDNA) A3243G mutation is one of the major causative factors of mitochondrial diabetes mellitus. We found that tissues from 2 of 142 diabetes mellitus patients showed extremely high levels of the mutation. OBJECTIVE: To investigate the level of the mutation in each tissue and to find the relationship between the mutation level and clinical features of the patients. METHODS: Patient 1 was a 51-year-old woman, diagnosed as having diabetes mellitus at the age of 17, and was admitted to hospital because of cerebral infarction. Patient 2 was an 82-year-old woman who was admitted because of respiratory failure. mtDNA A3243G levels were measured in tissues collected at autopsy. RESULTS: In patient 1, mtDNA A3243G levels were found to vary among the tissues. The patient's highest mtDNA A3243G value was 42% and the lowest value was 9%, whereas the level in most individuals is usually less than 1%. Although patient 2 did not exhibit serious clinical symptoms of diabetes mellitus, the mtDNA A3243G level was extremely high in all of the tissues surveyed (range 32-47%). CONCLUSION: Although both patients showed high levels of the mtDNA A3243G mutation, their clinical conditions differed greatly. Thus, mitochondrial diabetes mellitus patients may show a wide variety of clinical features and large variations in life span.

Structural alterations in outer arms of IgG oligosaccharides in patients with Werner syndrome.

Werner syndrome (WS) is a heredofamilial disorder characterized by clinicopathological premature aging. In healthy individuals, structural alteration of serum IgG oligosaccharides is known to be an aging phenotype. In the present study, we determined and compared oligosaccharide structures of serum IgG among WS patients, healthy age-sex-matched individuals, and healthy elderly individuals from both sexes in order to reveal whether WS patients exhibit an aging phenotype in terms of IgG oligosaccharide structure. Sialylation and galactosylation levels of IgG oligosaccharides from WS patients were similar to those from healthy elderly individuals in which sialylation and galactosylation levels were significantly lower than those from the healthy age-sex-matched individuals. In contrast, the bisecting N-acetylglucosaminylation level of IgG oligosaccharides from WS patients was comparable to that from the healthy age-sex-matched controls and significantly lower than that of the healthy elderly controls. There was no significant sexual difference in these modifications of IgG oligosaccharides. These results suggest that WS patients exhibit an aging phenotype for structural alterations such as sialylation and galactosylation in the outer arms of IgG oligosaccharides.

Telomere shortening with aging in the human pancreas.

We have conducted systematic studies to measure telomere length in human tissues of all types. Progressive telomere shortening with aging was studied in specimens of normal pancreas obtained at autopsy from 69 subjects aged 0 to 100 yr, and age-related shortening of telomere length at a rate of 36 base pairs (bp) per year was detected. Mean telomere length (+/-SD) was 13.9+/-1.4 kilobase pairs (kbp) in 16 neonates, as opposed to 8.4 kbp in 2 centenarians. Mean telomere length (+/-SD) in four age groups, 0-24, 25-49, 50-74, and 75-100 yr, was 13.5+/-1.5, 12.3+/-0.7, 11.3+/-2.5, and 10.7+/-1.8, respectively.

Association of TAP1 and TAP2 gene polymorphisms with systemic sclerosis in Korean patients.

We sought to determine whether transporter associated with antigen processing (TAP) gene polymorphism is associated with susceptibility to systemic sclerosis (SSc). TAP1 and TAP2 gene polymorphisms were analyzed in 61 Korean patients with SSc and 100 ethnically matched healthy Koreans by polymerase chain reaction-restriction fragment length polymorphism. Human leukocyte antigen (HLA)-DRB1 genotyping data of the patients from our previous study was used for the assessment of independent role of TAP genes to SSc susceptibility. Patients were stratified according to anti-topoisomerase I (anti-topo I) antibody status and clinical subsets of diffuse and limited cutaneous SSc (dcSSc and lcSSc). TAP1 and TAP2 gene polymorphisms were associated with different subsets of SSc: TAP1*A/A genotype with anti-topo I-positive dcSSc (p = 0.01, p corrected = 0.04), TAP2*A1/C genotype with anti-topo I-positive lcSSc (p < 0.05), TAP2*Bky2 and *C alleles with anti-topo I-negative dcSSc (both p < 0.05), and TAP2*B/E genotype with anti-topo I-negative lcSSc (p = 0.004). Although TAP gene associations were generally weak, some associations (TAP2*A1/C, TAP2*C, and TAP2*B/E) with different subsets of SSc were independent of HLA-DR associations, revealing even stronger associations (TAP2*A1/C and TAP2*C) among individuals not possessing the risk HLA-DR alleles. These results suggest the possible role of TAP gene polymorphisms in the genetic susceptibility to SSc.

Distribution of HLA-DR alleles among Thai patients with rheumatoid arthritis.

OBJECTIVE: This study was performed to investigate the association between the HLA-DR series and rheumatoid arthritis (RA) in a Thai population. METHODS: HLA-DR subtypes were determined in 100 Thai RA patients and 99 healthy controls (HC). HLA-DR typing was performed using INNO-LiPA HLA-DRB Decoder kits (Innogenetics) and reconfirmed using MICRO SSP HLA DNA Typing kits (One Lambda) for DRB1(∗)02 and (∗)04. RESULTS: When compared with the HC, the RA patients had higher allele frequency (AF) of DRB1(∗)04:05 (15.00% vs 7.07%, p=0.016, pc=NS, OR=2.319, 95%CI=1.189-4.522) and DRB1(∗)10:01 (3.00% vs 0%, p=0.030, pc=NS), respectively. The DRB1(∗)09:01 was slightly higher in the RA patients, without statistical significance. The AF of the shared epitope (SE) alleles (HLA-DRB1(∗)01:01, (∗)04:01, (∗)04:05 and (∗)10:01) was significantly higher in the RA patients (18.50% vs 7.58%, p=0.002, pc=0.046, OR=2.769, 95%CI=1.466-5.231, 99%CI=1.201-6.388). The AF of HLA-DRB4(∗)01 also increased significantly more in the RA patients (40.50% vs 25.76%, p=0.002, pc=0.002, OR=1.962, 95%CI=1.282-3.003, 99%CI=1.121-3.433). The HLA-DRB3(∗)03:01 was significantly lower in the RA patients (6.00% vs 14.14%, p=0.008, pc=0.023, OR=0.388, 95%CI=0.191-0.786, 99%CI=0.153-0.982). CONCLUSION: In the presence of SE, the DRB1(∗)04:05 and HLA-DRB4(∗)01 were associated with RA, and the DRB3(∗)03:01 would be a protective allele against RA in a Thai population.

Molecular Dynamics Simulation Reveals the Selective Binding of Human Leukocyte Antigen Alleles Associated with Behçet's Disease.

Behçet's disease (BD), a multi-organ inflammatory disorder, is associated with the presence of the human leukocyte antigen (HLA) HLA-B*51 allele in many ethnic groups. The possible antigen involvement of the major histocompatibility complex class I chain related gene A transmembrane (MICA-TM) nonapeptide (AAAAAIFVI) has been reported in BD symptomatic patients. This peptide has also been detected in HLA-A*26:01 positive patients. To investigate the link of BD with these two specific HLA alleles, molecular dynamics (MD) simulations were applied on the MICA-TM nonapeptide binding to the two BD-associated HLA alleles in comparison with the two non-BD-associated HLA alleles (B*35:01 and A*11:01). The MD simulations were applied on the four HLA/MICA-TM peptide complexes in aqueous solution. As a result, stabilization for the incoming MICA-TM was found to be predominantly contributed from van der Waals interactions. The P2/P3 residue close to the N-terminal and the P9 residue at the C-terminal of the MICA-TM nonapeptide served as the anchor for the peptide accommodated at the binding groove of the BD associated HLAs. The MM/PBSA free energy calculation predicted a stronger binding of the HLA/peptide complexes for the BD-associated HLA alleles than for the non-BD-associated ones, with a ranked binding strength of B*51:01 > B*35:01 and A*26:01 > A*11:01. Thus, the HLAs associated with BD pathogenesis expose the binding efficiency with the MICA-TM nonapeptide tighter than the non-associated HLA alleles. In addition, the residues 70, 73, 99, 146, 147 and 159 of the two BD-associated HLAs provided the conserved interaction for the MICA-TM peptide binding.

Comparison of the level of mitochondrial DNA A3243G mutation in esophageal epithelium and myocardium from individuals of very advanced age.

The A3243G mutation, one of the changes of human mitochondrial DNA (mtDNA) that accumulates in cells during aging, is a useful marker for investigating the aging of cells. We measured the mutation level of the mtDNA A3243G mutation using DNAs from two different tissues (esophageal epithelium and myocardium) from advanced elderly individuals. The mean level of the A3243G mutation for the esophageal epithelium was 0.0063+/-0.0019, and that for the myocardium was 0.0098+/-0.0031. The mutation level in the myocardium was significantly higher than that in the esophageal epithelium, indicating that more mtDNA A3243G mutations accumulated in the myocardium than in the esophageal epithelium. Since the myocardium is static with respect to cell turnover, but in the esophageal epithelium renewal is very rapid, it is possible that the mtDNA A3243G mutation in the myocardium accumulates more rapidly than in the esophageal epithelium. This phenomenon may reflect the difference in the longevity of cells in each of these tissues and their different levels of oxidative stress.