Dysregulation of long non-coding RNAs in Takayasu arteritis: A proof-of-concept study

Takayasu arteritis (TAK) is a rare systemic vasculitis primarily affecting the aorta and its major branches. Early diagnosis is critical to prevent severe vascular complications, yet current biomarkers are insufficient. This proof-of-concept study explores the potential of long non-coding RNAs (lncRNAs) in TAK, an area largely unexplored. In this cross-sectional study, 53 TAK patients, 53 healthy controls, and 10 rheumatoid arthritis (RA) patients were enrolled. Clinical evaluations, disease activity assessments, and lncRNA expression levels were analyzed. TAK patients exhibited significant dysregulation in several lncRNAs, including THRIL (19.4, 11.1-48.8 vs. 62.5, 48.6-91.4 arbitrary units [a.u.]; p < 0.0001), HIF1A-AS1 (4.5, 1.8-16.6 vs. 26.5, 19.8-33.7 a.u.; p < 0.0001), MALAT-1 (26.9, 13.8-52.5 vs. 92.1, 58.5-92.1 a.u.; p < 0.0001), and HOTAIR (8.0, 2.5-24.5 vs. 36.0, 30.0-43.8 a.u.; p < 0.0001), compared to healthy controls. Notably, HOTAIR (area under the ROC curve [AUC] = 0.825), HIF1A-AS1 (AUC = 0.820), and THRIL (AUC = 0.781) demonstrated high diagnostic potential with superior specificity (approximately 95%). While lncRNAs showed diagnostic promise, no significant correlations with TAK activity were observed. Comparative analysis with RA patients revealed distinct lncRNA expression patterns. This study unveils significant dysregulation of lncRNAs THRIL, HIF1A-AS1, and HOTAIR in TAK patients, underscoring their potential as biomarkers and opening avenues for further research into the mechanistic roles of these lncRNAs in TAK pathogenesis.

Angiogenesis related genes in Takayasu Arteritis (TAK): robust association with Tag SNPs of IL-18 and FGF-2 in a South Asian Cohort

We performed genetic association study for genes encoding angiogenic and angiostatic proteins in patients with Takayasu arteritis (TAK). A total of 96 SNPs involving 60 genes were studied. Genotyping was performed in Fluidigm 96.96 Dynamic Array chip. All statistical analysis for SNP evaluation was performed using PLINK software. Initial analyses revealed five SNPs from three genes [IL-18 (encodes Interleukin-18), FGF2 (encodes Fibroblast Growth Factor-2), and ANGPT1 (encodes Angiopoietin-1)] as significantly different between controls and cases (uncorrected p < 0.05). After permutation-based analysis, two tag SNPs on the promoter region of IL-18 (rs187238 and rs1946518) and one 3'UTR tag SNP (rs1476217) of FGF2 were significantly associated with susceptibility to TAK, with p and OR (95% CI) of 0.0006 and 1.64 (1.25-2.17), 0.03 and 1.28 (1.02-1.64) & 0.016 and 1.33 (1.05-1.67), respectively; while, the two tag SNPs of ANGPT1 gene (rs6469101 and rs16875900) showed a trend (p = 0.055 & p = 0.051, respectively after permutation based correction). There is robust linkage disequilibrium between the two tag SNPs of IL-18 gene as validated by 1000 genome data of South Asian population; the eQTL effects of these tag SNPs of IL-18 and FGF2 genes on adjacent genes further suggest that these tag SNPs act as genetic risks for development of TAK in South Asians, with possible functional implications towards future biomarker development. Genotype phenotype study by genetic model-based analysis also revealed associations between genotype subsets and clinical features like fever, visual loss, left subclavian and coronary artery involvement in our TAK patients.

High-throughput sequencing reveals the change of TCR α chain CDR3 with Takayasu arteritis

OBJECTIVE

Takayasu arteritis (TAK) is an inflammatory disease of blood vessels, and its pathogenesis is not clear at present. In this study, we explored the immunological characteristics of T cell receptor (TCR) α-chain complementarity-determining region 3 (CDR3) in patients with TAK.

METHODS

Five untreated patients with TAK were collected from June 2019 to December 2019. Four healthy blood samples were matched as the control group. The blood mononuclear cells were separated, and RNA was extracted for reverse transcription to obtain complementary DNA. Then high-throughput sequencing was performed. The quality of samples was evaluated by principal component analysis. We compared the diversity and expression of TCR α-chain between TAK group and control group. R software was used for statistical analysis and drawing, and Mann-Whitney U test was used to analyze the differences between the two groups.

RESULTS

The results showed that there was a significant difference in the diversity of TCR α-chain CDR3 between the two groups. Three V region genes expression significantly higher in the TAK patients than in the control group. A total of 196 VJ rearrangement genes are significantly different between the two groups, of which 149 rearrangement genes in the TAK group are lower than those in the control group, and 47 rearrangement genes in the TAK group are higher than those in the control group.

CONCLUSION

Patients with TAK have a unique TCR α-chain CDR3 library. These characteristic genes may be a marker for early diagnosis and provide a new theoretical basis for treating TAK.

Systemic review and meta-analysis of the association between interleukin-10 and Takayasu arteritis

OBJECTIVE

The aim of this meta-analysis is to investigate the relationship between interleukin (IL)-10 levels and its polymorphism and Takayasu arteritis (TAK).

METHODS

Five databases including PubMed, Web of Science, Ovid, Sinomed and China National Knowledge Infrastructure (CNKI) were gone through from inception to March 31, 2022. Studies were screened according to the inclusion and exclusion criteria. Newcastle-Ottawa Scale (NOS) was applied to assess study quality. Strengths of association were evaluated by odds ratio (OR) and 95% CI. The T v. t (allele contrast), TT v. tt (homozygous contrast), Tt vs tt (heterozygous contrast), TT + Tt vs tt (dominant contrast) and TT vs Tt + tt (recessive contrast) models were adopted.

RESULTS

Seven studies were included. No significant relationship between IL-10 and TAK was detected in the included patients (P > 0.05). The levels of IL-10 were lower in the active group than those in the stable group, which was -0.47 (95% CI: -0.93, 0.00) (P = 0.05). No significant relationships between IL-10 and TAK were found under all contrasts for polymorphisms rs1800871, rs1800872 and rs1800896 (P > 0.05).

CONCLUSIONS

There was no significant difference in IL-10 levels between TAK patients and control subjects. The levels of IL-10 were lower in TAK patients in the active stage. There was no significant association between IL-10 gene polymorphisms and TAK. Further well-designed studies with larger sample sizes in patients with different stages are needed.

Association of Killer Cell Immunoglobulin-like Receptor (KIR) Genes and their HLA Ligands with Susceptibility to Takayasu Arteritis in the Iranian Population

Takayasu arteritis (TA) is a chronic inflammatory disorder characterized by vascular damage and fibrosis in the intima that commonly occurs in the aorta. In many damaged sites in TA patients, natural killer (NK) cells have been shown to be hyperactivated and produce inflammatory cytokines and toxic components. Killer cell immunoglobulin-like receptors (KIRs) are found on NK cells and interact with human leukocyte antigen (HLA) class I ligands to activate or suppress NK cells. The present study assessed the possible role of KIR and their HLA ligand genes in susceptibility to TA in Iranian patients. This case-control study included 50 TA patients and 50 healthy subjects. DNA was extracted from whole peripheral blood samples, and polymerase chain reaction with sequence-specific primers (PCR-SSP) was performed to recognize the presence or absence of polymorphism in 17 KIR genes and 5 HLA class I ligands in each participant. Among the KIR and HLA genes, a significant decrease was detected in the frequency of 2DS4 (full allele) in TA patients (38%) compared with healthy controls (82%) (OR=0.13, 95% CI=0.05–0.34). However, none of the KIR and HLA genotypes or the interactions between these genes were associated with susceptibility to TA. The KIR2DS4 gene might be involved in the regulation of activation as well as the production of cytotoxic mediators of NK cells in patients with TA.

Comprehensive Analysis of the HLA Class I and the HLA Class II Alleles in Patients with Takayasu Arteritis: Relationship with Clinical Patterns and Prognosis

BACKGROUND

Takayasu arteritis (TA) is a systemic vasculitis, affecting mainly the aorta and its branches.

OBJECTIVE

To analyze the HLA class I and class II alleles in patients with TA and explore their relationship with clinical and demographic characteristics, and potential significance in prognosis.

METHODS

Twenty-five, unrelated TA patients were genotyped for HLA-A, HLA-B, HLA-C, HLA-DRB1, and the HLA-DQB1 loci. The frequencies of the HLA-A, HLA-B, and the HLA-DRB1 were compared with a control group of 1992, while the HLA-C and the HLA-DQB1 were compared with a group of 159 healthy, unrelated individuals.

RESULTS

Among TA patients, 5/25 (20%) were identified as the HLA-B*52 carriers. There was a significant difference in the HLA-B*52 allele frequency in the TA patients (10%) compared with the healthy controls (1.2%). Moreover, presence of the HLA-B*52 was associated with significantly earlier disease onset, more severe clinical presentations, and a poorer response to treatment. The HLA-C*03 was detected in 32% of patients and was present exclusively in those with a clinically mild form of the TA, indicating a putative protective effect.

CONCLUSION

These findings indicate that the HLA-B*52 allele contributes to a higher susceptibility to the TA whereas the HLA-C*03, can be a protective factor in the TA.

Lack of Association between Cytokine Genetic Polymorphisms in Takayasu's Arteritis in Mexican Patients

Aim: To investigate the relation between polymorphisms in the interleukin 10 (IL)-10, tumor necrosis factor (TNF)-α, transforming growth factor (TGF)-β and interferon (IFN)-γ genes and Takayasu's arteritis in the Mexican population. Methods: A case-control study was performed to investigate the associations of IL-10, TNF-α, TGF-β and IFN-γ polymorphisms in a sample of 52 Takayasu's arteritis patients, diagnosed according to the criteria of the American College of Rheumatology and EULAR PRINTO criteria when the patients were under 18 years of age; 60 clinically healthy unrelated Mexican individuals by the 5' exonuclease TaqMan polymerase chain reaction. Polymorphic haplotypes were constructed after linkage disequilibrium analysis. Results: Significant differences were not found in the distribution for genotype and allele frequencies of the polymorphisms studied between healthy controls and Takayasu´s arteritis patients. Likewise, significant associations were not detected in the haplotype analysis with the different genes studied. Conclusions: These findings suggest that the polymorphisms in IL-10, TNF-α, TGF-β and IFN-γ might not contribute to the susceptibility of Takayasu´s arteritis in the Mexican population.

Hemoptysis Originating from the Bronchial Artery in Takayasu Arteritis with Ulcerative Colitis

Takayasu arteritis (TAK) is a large-vessel vasculitis affecting the aorta and its main branches. Hemoptysis can be experienced as the respiratory manifestation, but origination from a bronchial artery is rare. Ulcerative colitis (UC) shares genetic similarities with TAK; HLA-B52*01 is associated with TAK and UC. We herein report a patient who presented with hemoptysis from the right bronchial artery and was diagnosed with TAK during the follow-up of UC. Transcatheter embolization was performed, and prednisolone and tocilizumab induced remission. Complication of TAK should be considered in the clinical course of HLA-B52-positive UC patients, and tocilizumab may be a treatment option.

Tumor necrosis factor-alpha -308G/A gene polymorphism and novel biomarker profiles in patients with Takayasu arteritis

Background

Takayasu arteritis (TA) is an idiopathic chronic inflammatory disease of the aorta and its branches, leading to stenosis, occlusion, and aneurysmal dilatation. Tumor necrosis factor-alpha (TNF-α) is a cytokine with pleomorphic actions and plays a pivotal role in inflammation; the serum level of TNF-α is genetically determined. However, the literature lacks adequate information on the association of TNF-α polymorphisms with TA. Hence, the present study investigates the contribution of TNF-α polymorphism toward the complex etiology of TA.

Methods

A cross-sectional study was performed in 87 patients with TA and 90 controls. A promoter region polymorphism of TNF-α, rs1800629 G/A, or −308G/A was genotyped in all the study subjects followed by a case–control association study. Furthermore, to understand the biomarker profile, levels of specific markers such as erythrocyte sedimentation rate, serum high-sensitivity C-reactive protein, interleukin-18, interleukin-6, and TNF-α were measured in all the study subjects.

Results

All the inflammatory markers were significantly higher in the TA patients than in the controls. The genetic study (available for 57 TA patients and 36 controls) revealed that the TNF-α −308A allele was overrepresented in the TA patients (12% vs 7%). The TNF-α −308A allele correlated with the increased TNF-α levels, but it could not attain significance because of a small sample size.

Conclusion

The TNF-α −308G/A polymorphism is associated with TNF-α levels in Indian population, which might have implications for clinical risk stratification and treatment. The different TNF-α gene promoter polymorphism might contribute to the molecular pathogenesis of TA. However, further study of the underlying mechanism is warranted.

Soluble-HLA-E: A follow up biomarker in Takayasu arteritis, independent of HLA-E genotype

AIM

Disease activity assessment in Takayasu arteritis (TA) is challenging. Human leukocyte antigen E (HLA-E) is shed from endothelium into serum as a soluble molecule (sHLA-E) in response to inflammation. We aimed to study: (i) utility of sHLA-E as a biomarker of disease activity; and (ii) association of HLA-E polymorphism rs1264457 with clinical disease in Asian-Indian TA patients.

MATERIALS AND METHODS

In phase-1, sHLA-E levels were estimated in sera of 50 consecutive TA patients at baseline visit and 27 healthy controls. Serial estimations were performed in 27 of them. In phase-2, DNA of 150 TA patients and 264 healthy controls were genotyped for rs1264457 polymorphism.

RESULTS

At baseline visit, disease was classified as active, stable and grumbling in 23, 18 and nine patients, respectively. sHLA-E levels were higher in active TA (43; interquartile range [IQR]: 25.3-64.6) pg/mL) than stable disease (12.9; IQR: 7.6-21.6 pg/mL) (P = 0.001). At first follow-up visit, sHLA-E levels were numerically higher in active disease than stable disease (P = 0.06) but this trend was blunted at second follow-up. sHLA-E levels increased in 54% versus 25% of patients with persistently active/relapsing and persistent stable course, respectively. rs1264457 polymorphism was not associated with susceptibility to TA and did not affect sHLA-E levels.

CONCLUSION

sHLA-E level is useful as a biomarker of disease activity and course in TA patients. rs1264457 polymorphism is neither associated with susceptibility nor did it influence sHLA-E levels in TA.

The genetics of Takayasu arteritis

Takayasu arteritis (TAK) is a rare systemic vasculitis that is characterized by granulomatous inflammation of the aorta and its major branches. The cellular and biochemical processes involved in the pathogenesis of TAK are beginning to be elucidated, and implicate both cell and antibody-mediated autoimmune mechanisms. In addition, the underlying etiology to TAK may be explained, at least in part, by a complex genetic contribution. The most well-recognized genetic susceptibility locus for the disease is the classical HLA allele, HLA-B*52, which has been confirmed in several ethnicities. The genetic susceptibility with HLA-B*52, as well as additional classical alleles and loci, implicate both HLA class I and class II involvement in TAK. Furthermore, genetic associations with genes encoding immune response regulators, pro-inflammatory cytokines and mediators of humoral immunity may directly relate to disease mechanisms. Non-HLA susceptibility loci that have been recently established for TAK with a genome-wide level of significance include FCGR2A/FCGR3A, IL12B, IL6, RPS9/LILRB3, and a locus on chromosome 21 near PSMG1. In this review, we present the complex genetic predisposition to TAK and discuss how recent findings identified potential targets in the pathogenesis and treatment of the disease.

Interleukin-17F and interleukin-6 gene polymorphisms in Asian Indian patients with Takayasu arteritis

OBJECTIVES

To assess genetic association between single nucleotide polymorphisms (SNPs) in genes encoding T-helper cytokines and Takayasu Arteritis (TA) susceptibility in Asian Indian population.

METHODS

In Phase-1, the genomic DNA of 120 TA patients and 119 healthy controls were genotyped for SNPs rs1800795 (interleukin (IL)-6), rs763780 (IL-17F), rs1800871, rs1800872, rs1800896 (IL-10) and rs1800468, rs1800469, rs1800470 (transforming growth factor-β). Allele frequencies between cases and controls were compared using chi-squared test and also reassessed empirically (p_e) by 10,000 permutations. In Phase-2, additional 98 TA patients and 101 controls were genotyped for replicating the significant associations noted in Phase-1 of the study.

RESULTS

All 8 SNPs in Phase 1 were in Hardy-Weinberg proportions. The G allele at rs763780 (IL-17F) was significantly associated with TA (p=0.014). We also found that rs1800795 (IL-6) was associated with tuberculosis (p=0.001) under a dominant model. In Phase-2 replication part of the study, the rs763780 showed a trend towards association with TA (p=0.08), and the magnitude and direction of the odds ratio (OR) also were consistent with results of Phase-1. In the combined analysis, protective association of the G allele of rs763780 with TA was again significant [OR (95% CI)=0.44 (0.25-0.77); p=0.0029]. The G allele was also significantly associated (p<0.05) with underlying tuberculosis (TB) and occurrence of syncope in TA.

CONCLUSION

G allele of rs763780 in IL-17F gene was protectively associated against susceptibility to TA. GG genotypes of rs1800795 in IL-6 was also associated with occurrence of tuberculosis in our patients with TA.

Single nucleotide polymorphisms of IL12B are associated with Takayasu arteritis in Chinese Han population

Takayasu arteritis (TA) is a rare autoimmune disease of unknown etiology. Genome-wide association studies (GWAS) have demonstrated association between genetic variants of IL12B and IL6 and TA. Since TA has been reported with ethnic heterogeneity, we sought to investigate whether the single-nucleotide-polymorphisms (SNPs) reported in these studies are associated with TA in the Chinese Han population. A multi-center study involving 412 patients with TA and 597 healthy controls was conducted. Sequenom MassArray iPLEX platform was used to determine the frequencies of SNPs in the IL12B and IL6 region. We demonstrated a allele association between the four SNPs of IL12B and TA (rs6871626: OR 1.52, 95% CI 1.26-1.83; rs4921492: OR 1.46, 95% CI 1.21-1.75; rs60689680: OR 1.41, 95% CI 1.17-1.69; rs4921493: OR 1.45, 95% CI 1.21-1.75, all P _c  < 10^- 3 ). A meta-analysis consist of four populations showed rs6871626 was a susceptible locus of TA. Its OR was 1.51, and 95% CI was 1.31-1.74. The four SNPs were in strong linkage disequilibrium and two haplotypes were significantly different between patients and controls. Conditional analysis shows that these SNPs were not independent factors contributing to TA. Nevertheless, neither genotype nor allele frequencies of rs2069837 in IL6 showed significant between-group differences. Thus SNP of IL12B may be considered a high-risk factor for TA in Chinese Han population and provide further clues for research into the pathogenesis of TA.

A case of infantile Takayasu arteritis with a p.D382E NOD2 mutation: an unusual phenotype of Blau syndrome/early-onset sarcoidosis?

Blau syndrome/early-onset sarcoidosis (Blau/EOS) is an autoinflammatory disease characterized by granulomatous arthritis, uveitis, and skin rash. It has been shown that gain-of-function NOD2 mutations cause Blau/EOS. In this paper, we describe a patient with a gain-of-function NOD2 mutation who developed infantile Takayasu arteritis, which is rare in Blau/EOS, but who has not yet had significant granulomatous changes in joints, eyes, or skin. We suspect that this case is an unusual phenotype of Blau/EOS.

[Expression of human B-cell specific receptor FCRL1 in normal individuals and in patients with autoimmune diseases]

The comparative analysis of expression level of FCRL1 gene encoding human B-cell surface receptor in healthy individuals and patients with autoimmune diseases was carried out. For the expression estimation we used results of DNA dot-hybridization on the membranes, containing cDNA samples from subpopulations of blood cells of patients with autoimmune diseases. The quantitative estimation of hybridization signals showed that expression level of FCRL1 gene in peripheral blood B-lymphocytes was significantly higher in patients with a multiple sclerosis, lupus anticoagulans, Takayasu's arteritis and also in von Willebrand disease than in healthy individuals. FCRL1-specific monoclonal and polyclonal antibodies were raised. They were proven to detect FCRL1 in Western blotting, immunohistochemistry and flow cytometry. It was found that FCRL1 is expressed on the surface of CD19+ mature B-cells. In tonsil FCRL1-positive cells were located in crypt area: in mantle zone of secondary lymphoid follicles and among cells of lymphoepithelium. FCRL1-positive cells were also found in B-cell follicles of the spleen.

PDCD1 polymorphisms are not associated with Takayasu's arteritis in Turkey

OBJECTIVES

Takayasu's arteritis (TA) is a chronic arterial inflammation of unknown etiology involving mainly the aorta and its major branches. Based on the associations of programmed death-1 (PD-1) protein encoding gene (PDCD1) with connective tissue diseases and vasculitides, PDCD1 polymorphisms are studied for susceptibility to TA in this study.

METHODS

The study group is made up of TA patients (n=229) fulfilling the 1990 ACR classification criteria and compared to 193 healthy controls (HC). PD-1.3, PD-1.5 and PD-1.6 single nucleotide polymorphisms of PDCD1 gene are genotyped by polymerase chain reaction and restriction analysis (PCR-RFLP).

RESULTS

The distribution of PD-1.5 polymorphism in TA patients and HC revealed a similar presence of TT genotype in patients and controls (13.3% vs. 11.4%). PD-1.3 and PD-1.6 were less polymorphic and did not differ between the groups. Rare AA genotype of PD-1.3 (1.4% vs. 1.0%) and AG genotype of PD-1.6 was again similarly (22.4% vs. 19.2%) present in TA and HC.

CONCLUSIONS

PD-1.3, 1.5 and 1.6 polymorphisms of PDCD1 gene, which were shown to be associated with various autoimmune disorders and vasculitides, are not associated with a susceptibility to TA in Turkish population.

Takayasu arteritis: epidemiological, clinical, and immunogenetic features in Greece

OBJECTIVE

Takayasu arteritis (TA) is an uncommon disease with clinical heterogeneity across different ethnic groups. We aimed to evaluate the epidemiological, clinical, and immuno-genetic features of TA in Greece.

METHODS

Demographic, clinical, laboratory, angiographic, and therapeutic data of 42 patients from 4 large referral centers were retrieved. Serology and Human Lymphocyte Antigen (HLA) typing was performed in 22 patients.

RESULTS

We studied 37 women and 5 men with a median age of 31 years at disease onset. Median delay in diagnosis was 24 months and median follow-up was 47 months (range 0-178). Constitutional or musculoskeletal symptoms were present in 86%, especially early in the disease course. Vascular findings were universal with reduced or absent pulse being the most common manifestation (98%). Hypertension was frequent (78%). Extensive disease prevailed and stenotic lesions were more common than aneurysms (95% vs. 40%). Erythrocyte sedimentation rate and C-reactive protein showed modest correlation with disease activity. HLA-B52 was expressed by 37% of the patients vs. 2.4% of the controls (p<0.001). Glucocorticoids and cytotoxic agents were used in most patients with remission rates of 83%. A total of 42 surgical procedures were performed with success rates of 87%.

CONCLUSION

TA in Greece clinically and epidemiologically resembles the pattern of disease in Japan and the Western hemisphere. There is considerable delay in diagnosis, which may partially reflect failure to recognize a rare disease. New surrogate markers are needed to assess disease activity. Glucocorticoids are the cornerstone of treatment and cytotoxic drugs are frequently used as steroid sparing agents.

Atypical Takayasu arteritis: a family with five affected siblings

BACKGROUND

Takayasu disease is a giant cell arteritis, primarily affecting the aorta and its main branches, particularly over the first 1.5 cm. It is more common in South-East Asian countries and in young females, whose clinical manifestations range from asymptomatic to catastrophic neurological impairment.

CASE REPORT

We report on a Pakistani family in which five of seven siblings, aged 12 to 19 years, are affected with atypical Takayasu arteritis. The proband is a 14-year-old male who presented with sudden, painless loss of vision. He was found to have absent pulses, retinal changes and magnetic resonance angiography (MRA) findings diagnostic of Takayasu arteritis. In addition, though, he had decreased intraocular pressure, murmur of mitral valve prolapse, as well as atypical involvement of the aorta as visualized in MRA and decreased renal blood flow; these last three findings are not usual features of the disease. The unique involvement in the aorta indicates that this patient corresponds to yet another sub-type in the angiographic classification of TA. Four siblings of the proband are asymptomatic but fulfill the diagnostic criteria of the American College of Rheumatology. This is the first reported multiplex family with Takayasu arteritis, in which more than two members meet the diagnostic criteria.

CONCLUSIONS

Previous reports indicate possible HLA associations of Takayasu disease in Japanese patients. Our present study indicates both that there may be clinical and etiological heterogeneity in Takayasu disease, and the possibility that an autosomal recessive form of the disease exists.

Comparison Distribution of HLA-B Alleles in Mexican Patients with Takayasu Arteritis and Tuberculosis

A possible relationship between Takayasu arteritis (TA) and Tuberculosis (Tb) has been suggested. Both diseases present similar chronic inflammatory lesions and occasionally granulomas on the arterial walls. The genetic relationship between these two diseases has not been explored before, however, both diseases have been associated with human leukocyte antigen (HLA) alleles. Therefore, the aim of the present study was to analyze the distribution of HLA-B alleles in TA (n = 40) and Tb (n = 34) patients and healthy controls (72 exposed and 99 nonexposed). HLA-B alleles were determined by reverse dot blot. The statistical methods used included the Chi(2), and odds ratio (OR) with 95% confidence intervals. In spite of the loose clinical relationship between TA and Tb, we did not detected any genetic relationship between them when the HLA-B alleles were analyzed in these groups of patients. On the contrary, we detected distinct specific HLA-B alleles for each disease. TA was characterized by HLA-B39, -B44, and -B52, pulmonary Tb by HL-B35 and extrapulmonary Tb by HLA-B39 and -B40. This preliminary study suggests a difference in the distribution of HLA-B alleles in patients with TA and Tb.

HLA alleles in Korean patients with Takayasu arteritis

In this study, we investigated the HLA allele and haplotype frequencies, and the association of HLA alleles with serious complications and angiographic findings in Korean patients with Takayasu arteritis (TA) compared with healthy controls. Sixty-one patients (56 women, 5 men), diagnosed with TA between January 1995 and December 2005, were studied. Ninety-five healthy men and women were selected as controls. Clinical manifestations were assessed and angiographies were performed at the time of diagnosis in all TA patients. Genotypes of the HLA-A, -B and -DRB1 loci were determined using the polymerase chain reaction-sequencing-based typing (PCR-SBT) method. The mean age at the time of diagnosis of TA was 37.0+/-12.1 years. Compared with controls, the frequencies of A*3001 (p=0.048), B*5201 (p=0.025), and DRB1*1502 (p=0.046) alleles were significantly higher in TA patients, and the frequency of A*2602 was significantly lower in TA patients when compared with controls (p=0.047). The haplotype containing A*2402-B*5201-DRB1*1502 was significantly increased in TA patients (chi2=5.45, p=0.01). Further, among the serious complication of TA, congestive heart failure (CHF) was found to be associated with B*5201 (OR=5.94, p<0.05, 95% CI=1.04 33.85). These data suggest that A*3001, B*5201, and DRB1*1502 alleles might increase the susceptibility to TA, while A*2602 might protect against TA. Further, our results reveal that the haplotype A*2402-B*5201-DRB1*1502 could be a risk factor for TA, and the allele B*5201 is significantly associated with CHF.

Interleukin (IL)-12, IL-2, and IL-6 gene polymorphisms in Takayasu's arteritis from Turkey

Takayasu's arteritis (TA) is a chronic arterial inflammation of unknown etiology involving mainly the aorta and its major branches. Genetic polymorphisms of cytokines are screened as susceptibility factors for TA in Turkey. A total of 94 patients with TA were investigated for the genetic polymorphisms of the interleukin genes IL12, IL2,and IL6 and were compared with 108 healthy control subjects using polymerase chain reaction-sequence-specific primer method. The frequencies of IL12B 1188 C allele (p = 0.03, OR = 1.7) and CC genotype (p = 0.007, OR = 3.7) were both higher in TA patients than in control subjects. TT genotype at IL2-330 (p = 0.006, OR = 2.4) and GG genotype at IL6-174 (p = 0.04, OR = 1.9) were more frequent in TA patients. Lower prevalence of GT genotype at IL2-330 (p = 0.005, OR = 0.4), CG genotype at IL6-174 (p = 0.001, OR = 0.4), and AG genotypes at IL6-598 (p = 0.01, OR = 0.4) were also detected. The polymorphism of IL-12 as well as IL-6 and IL-2 genes may contribute to susceptibility and pathogenesis of TA by altering cytokine production and inducing inflammation.

Direct Determination of Single Nucleotide Polymorphism Haplotype of NFKBIL1 Promoter Polymorphism by DNA Conformation Analysis and Its Application to Association Study of Chronic Inflammatory Diseases

We previously revealed that one of the human leukocyte antigen-linked susceptibility genes for Takayasu's arteritis (TA) was mapped between TNFA and MICB loci and that -63T allele of NFKBIL1, which is between TNFA and MICB loci, was associated with rheumatoid arthritis (RA) in the Japanese population. We have developed a novel typing method based on reference strand-mediated conformation analysis for the upstream sequence of the NFKBIL1 gene, where -422 (T)8/(T)9, -325 C/G, -263 A/G, and -63 T/A polymorphisms were found. Upon the analysis of the patients with TA (n = 84), those with RA (n = 120), and healthy control subjects (n = 217), five common haplotypes named IKBLp*01 through IKBLp*05 were found in the Japanese population. The frequency of IKBLp*03 was significantly increased in the patient with TA (57.1% vs 35.0%, giving an odds ratio of 2.47). In addition, the frequency of IKBLp*01, but not that of other -63T-bearing alleles, was increased in the patients with RA (73.3% vs 58.1%, giving an odds ratio of 1.99), suggesting that the susceptibility to RA was conferred not by -63T alone but by combination of single nucleotide polymorphisms in the NFKBIL1 promoter. A higher promoter activity associated with IKBLp*03 and a lower activity associated with IKBLp*01 may contribute to the susceptibility to TA and RA, respectively.

Cerebral arteriopathy with extracranial artery involvement in a patient with ulcerative colitis

Arteriopathy of the central nervous system (CNS) complicated with ulcerative colitis is a rare condition, moreover the involvement of extracranial arteries has not been documented. An 18-year-old female complained of a severe pulsatile headache and nausea. She had been diagnosed and treated for ulcerative colitis for four years. Magnetic resonance imaging of the brain showed normal results; however, magnetic resonance angiography (MRA) revealed severe irregularity of the intracerebral arteries. After treatment with prednisolone, the patient fully recovered and the irregularity of the intracerebral arteries was dramatically improved. Vasculitis was strongly suggested as the cause of arteriopathy of the CNS in the present case. Involvement of extracranial arteries such as the carotid artery was also incidentally discovered by duplex ultrasonography and the HLA typing suggested genetic susceptibility to Takayasu's arteritis. Findings from our patient suggest that extracranial arterial involvement should be considered in the case of arteriopathy of the CNS associated with ulcerative colitis.

T-cell receptor repertoire of circulating gamma delta T-cells in Takayasu's arteritis

We studied T-cell receptor (TCR) repertoire of circulating gamma delta (gammadelta) T-cells in 20 patients with Takayasu's arteritis (TA), 20 healthy controls (HC), 7 follow up TA patients, and 10 patients with rheumatoid arthritis (RA) and 5 Wegener's granulomatosis (WG) patients as disease controls. Patients with TA (8.1 +/- 5.1%) compared to HC (3.7 +/- 2.1%, P = 0.014), RA (4.8 +/- 0.6%, P = 0.032), and WG (4.2 +/- 0.8%, P = 0.030) as well as active TA compared to inactive TA (13.9 +/- 4.1% vs. 4.9 +/- 1.5%; P < 0.001) had higher number of gammadelta T-cells. The numbers of Vdelta1+ cells were significantly higher in patients with TA (40.0 +/- 20.8%) than HC (13.1 +/- 8.0%; P = 0.001), RA (19.5 +/- 1.8%, P = 0.004), and WG (17.0 +/- 3.9%, P = 0.007). The numbers of gammadelta T-cells normalized in all the 7 patients after 180 days of follow up (13.9 +/- 4.1% vs. 6.9 +/- 2.5%; P = 0.001). We also observed higher number of activated and IFN-gamma producing gammadelta T-cells in active TA. Our data show that gammadelta T-cells particularly those bearing Vdelta1 TCR may have an important role in the immunopathogenesis of TA.

Takayasu Arteritis with High Titre of Antiphospholipid Antibodies and MTHFR Polymorphism

The association of antiphospholipid antibodies and Takayasu arteritis is very rare and few cases have been reported in the past. Though Takayasu arteritis patients were treated in the past with stenting, there have been no reports of patients with this association being treated with carotid stenting. We present here a young Bahraini female with Takayasu arteritis, primary antiphospholipid antibody syndrome and methylene tetrahydrofolate reductase C 677 T and A 1298 C polymorphism, who was treated with carotid stenting and anticoagulants.

Comparative study of the residues 63 and 67 on the HLA-B molecule in patients with Takayasu's Arteritis

Takayasu's Arteritis (TA) has been associated with the Major Histocompatibility Complex (MHC) genes; nevertheless, results in several populations have been heterogeneous. Studies both in Mexican and Asian populations suggest that residues at positions 63 (glutamic acid) and 67 (serine) of the HLA-B molecule could be the genetic markers for TA. In the present work, we analyzed the sequence of HLA-B alleles in 26 TA patients and 62 healthy controls. HLA-B subtyping analysis showed that all B52 alleles were B*5201, whereas only one HLA-B39 allele was B*3902. Sequencing of HLA-B alleles showed that 19 out of 26 patients studied (73.0%) presented at least an allele with glutamic acid at position 63 and serine at position 67. This condition was observed in only 21.0% of the healthy controls (pC = 0.00001, OR = 10.23). Out of the seven remaining patients, one presented glutamic acid at position 63 and four showed serine at position 67. Two patients (2/26 = 7.7%) and 24 healthy controls (24/62 = 38.7%) did not show similarity at the mentioned positions (pC = 0.016, OR = 0.13). These data corroborate the participation of positions 63 and 67 in the genetic susceptibility to TA and explain the high heterogeneity of alleles associated with the disease in several populations.

Angiographic findings and surgical treatments of coronary artery involvement in Takayasu arteritis

BACKGROUND

Takayasu arteritis is associated with a low incidence of coronary artery involvement, such as stenosis, obstruction, aneurysm, and coronary steal syndrome, but coronary ischemia can be fatal.

METHODS

Between 1972 and April 2001, 81 of 130 patients given a diagnosis of Takayasu arteritis underwent selective coronary angiography, and among them, 31 patients (4 male and 27 female patients; mean age, 41.1 +/- 13.2 years) had abnormal coronary angiographic findings and were recruited for this study.

RESULTS

Abnormal coronary findings consisted of 24 coronary artery stenoses of greater than 75%, 3 coronary artery-bronchial artery anastomoses, 3 aneurysmal coronary ectasias, and 1 combined coronary ectasia and anastomosis. Among 24 patients with coronary stenosis, the ostium was most frequently involved (87.5%). Twenty-three of 24 patients with coronary artery stenoses were treated surgically. The mean follow-up duration was 9.65 +/- 6.9 years, with a 100% follow-up rate. Four fistulas and 4 aneurysms in 7 patients were not treated surgically. Coronary steal phenomenon was always associated with occluded pulmonary arteries and pulmonary hypertension. Aneurysmal coronary ectasia was related to severe aortic hypertension with or without aortic regurgitation and atypical coarctation. There were 2 (8.7%) in-hospital deaths and 3 (13%) late deaths. The actuarial survival rate, including in-hospital deaths, was 86.5% +/- 7.3% at 5 years and 81.4% +/- 8.4% at 10 years.

CONCLUSION

The incidence of coronary abnormalities is relatively low in patients with Takayasu arteritis; however, surgical treatment is recommended for patients with coronary ostial stenoses because coronary ischemia can be one of the major causes of death.

Ulcerative colitis associated with Takayasu's disease in two patients who received proctocolectomy

Ulcerative colitis (UC) associated with Takayasu's disease (TD) is not common in Japan. Here, we report two patients with both diseases who received a total proctocolectomy. Patient 1, a 41-year-old woman with chronic continuous type UC, was first diagnosed with TD at the age of 10 years. Subsequently, she was diagnosed with UC and rectal cancer. HLA typing showed A2, A31(19), B52(5), and DR2(DRB1*1502). Coronary angiography showed 90% narrowing of the right coronary artery (RCA). After alleviating the RCA narrowing by percutaneous transluminal coronary angioplasty (PTCA), we performed a total proctocolectomy and ileostomy. Patient 2, a 20-year-old woman, was first diagnosed with TD at the age of 13 years. Severe symptoms, indicating fulminant UC, started 1 month prior to hospitalization. She was judged as needing surgery because the symptoms were not alleviated even with high doses of prednisolone. HLA typing showed A2, A31(19), B52, B61(40), DR2(DRB1*1502), and DR4 (DRB1*0405). Aortography showed a narrowing of the right renal artery; however, her renal function was normal. Based on these findings, we performed a three-stage operation for total proctocolectomy. Previously, we have reported that the DRB1*1502 and DRw11 genes were closely related to the intractability of UC. To date, we have not determined whether or how the DRB1*1502 gene might be related to TD. As the number of cases of UC associated with TD increases, it will be necessary to examine their DR2 subtypes.

[Alleles of the major histocompatibility system associated with susceptibility to the development of Takayasu's arteritis]

OBJECTIVE

Since 1972, the relationship between HLA alleles and the susceptibility for Takayasu arteritis (TA) has been studied on different populations. Hence the results up to date are heterogeneous, the objective of the present review is to analyze the relationship between the presence of HLA alleles and the susceptibility for the development of TA considering the ethnic origin of the studied populations.

MATERIAL AND METHODS

We carried out a bibliographic review from clinical articles of case and controls studies on different populations on which the relationship between HLA alleles and the susceptibility for TA was studied, published since 1972 until February 2000.

RESULTS

We reviewed articles of studies on Asian, Arab, North-American and Mexican Mestizo populations. On Asian populations TA was associated with HLA-A31, -B52, -B39, -B5 and -DR2, on Arabs with HLA-A2, -A9, -B35 and -DR7, on North-Americans with HLA-DR4 and on Mexican Mestizo with HLA-B5, -B52 and -DR6. On the other hand, recent reports establish that several HLA-B alleles (HLA-B52 and HLA-B39) associated with the disease share some residues important on the antigen presentation.

CONCLUSIONS

Hence the heterogeneity of the results obtained up to date, it stands out the increase on HLA-B52 and HLA-DR4 reported on ethnically different populations. More recent data point the possible participation of an epitope located on the peptide-binding site of the HLA-B molecule (positions 63 and 67) that seems to be shared by several alleles associated with the disease. These residues might be participating on the presentation of an unknown antigen that would unchain the disease on the genetically susceptible individuals group.

Immunogenetics of peripheral arteriopathies

Takayasu's arteritis (TA) and thrombangiitis obliterans (Buerger's disease) are idiopathic, inflammatory arteriopathies with strong indications for the involvement of autoimmunity and host genetic factors in their immunopathogenesis. The exact etiology of these arteriopathies still remains unknown even after almost nine decades of their description. A series of immunogenetic studies conducted worldwide seeking to define genetic factors in governing immune response in these diseases have yielded conflicting results on the involvement of HLA molecules. While an association of HLA-B5 or its molecular subtypes with Takayasu's arteriitis has been emphasized in patients from Japan, Korea and India, no such association has been reported in Mexican and North American patients. On the other hand, a limited data is available on the association of HLA antigens with Buerger's disease. In this article, we provide an overview of the immunogenetics of Buerger's disease and Takayasu's arteriitis in the context of studies in North Indian patients and those in other ethnic groups. Our studies indicate a positive association of Takayasu's arteriitis with the HLA-B5 molecule with no preferential association with its two major subtypes. In Buerger's disease, we have observed a strong positive association with HLA-DRB1*1501 consistent with the findings in Japanese patients. These results suggest an important role of HLA linked factors in governing susceptibility to both arteriopathies.

Immunogenetics and clinical aspects of Takayasu's arteritis patients in a Mexican Mestizo population

OBJECTIVE

The aim of the present work was to study the association between HLA alleles and Takayasu's arteritis in Mexican Mestizo patients.

METHODS

The study included 26 Mexican Mestizo patients with Takayasu's arteritis and 99 healthy unrelated individuals. HLA-A, -B and -DR alleles were determined by polymerase chain reaction PCR-SSP RESULTS: Increased gene frequencies were demonstrated for HLA-B15(p=0.009,pC=0.020,OR=3.24,EF=11.9%) and HLA-B52 (p=0.008, pC=0.027, OR=5.16, EF=7.7%), and a decreased frequency for the HLA-A24 allele in patients compared to normal controls (p=0.035, pC=NS, PF=11.1%). When HLA typing was correlated to clinicalfeatures in 24 cases, wefound an increasedfrequencies of HLA-DR14 in patients with systemic arterial hypertension (p=0.005, pC=0.004, OR=24.6, EF=38.3%) and HLA-A2 on patients with pulmonary involvement (p=0.034, pC=0.036, OR=3.67, EF=40.4%) when compared to patients without these clinical manifestations.

CONCLUSION

These data confirm HLA-B52 as a relevant susceptibility allele for Takayasu's arteritis and suggest that HLA-B15 could be important as a marker of the disease in Mexican patients. Other class I and/or class II alleles could also be relevant as markers for the clinical features present in these patients.

DNA sequencing of HLA-B alleles in Mexican patients with Takayasu arteritis

Takayasu arteritis (TA) is characterized by a 'pulseless' condition and occurs frequently in young females from Asian and South American countries. It has been associated with Mayor Histocompatibility Complex (MHC) genes in different populations. Recent data indicate direct participation of HLA-B alleles in the susceptibility to the disease. This fact was explored in an associative study with TA to establish if some region in the exon 2, intron 2 or in the exon 3 of HLA-B alleles is common in the alleles associated with TA and at the same time to know if a specific sequence or an epitope, more than an allele, would be responsible for the susceptibility to this vasculitis. We studied HLA-B alleles of 12 Mexican patients with TA using PCR-SSP and sequencing. The analysis by PCR-SSP in 12 patients showed that five of them showed the B*15 allele, three the B*40 allele and two the B*39 allele, the remaining two presented the B*44 allele. Sequence analysis enabled us to define that the B*39 subtypes are B*3908; B*15 subtypes are B*1510, B*1515, B*1522 and B*1531; and the B*40 subtypes are B*4005 and B*4008. An individual with B*51 (B*5107) and another with B*52 (B*5201) alleles were also identified. The sequences of the intron 2 seem be heterogeneous. Analysis at the 63 and 67 positions of HLA-B alleles showed that 9 of them have similarity in some of these positions with the residues detected in the B*5201 and B*3902 alleles associated with TA in Asian populations. The results indicate that there is heterogeneity in the alleles associated with TA in Mexicans but, in spite of that heterogeneity, the alleles associates can be separated into three groups: B*39, B*15 and B*40, whose subtypes are rare and apparently of recent generation in Mexico, probably by recombination events at intron 2 level. The sequences analysis also shows that most of the alleles detected in the Mexican patients share two epitopes described in the susceptibility alleles in Asian populations, suggesting that these epitopes could be responsible for the susceptibility to develop the disease in spite of the allele in which are found.

Association of HLA-DRB1*1602 and DRB1*1001 with Takayasu arteritis in Colombian mestizos as markers of Amerindian ancestry

We performed HLA Class I and Class II typing in 16 patients (15 women, one man) with a confirmed diagnosis of Takayasu arteritis. We did not find any of the previously described associations with HLA-B52, and/or HLA-DRB1*1301 alleles. However, in our patients, HLA-DRB1*1602 and HLA-DRB1*1001 were significantly increased. The association of Takayasu arteritis with Amerindian and Asian HLA-DRB1 alleles (DRB1*1602 and DRB1*1001) in the Colombian mestizo patients reported here, and with HLA-B*3906 previously reported in Mexicans, suggest the possibility that some HLA and disease associations are markers for ethnicity of a population carrying a disease gene which is present in an admixed population with the disease.

Mapping of the HLA-linked genes controlling the susceptibility to Takayasu's arteritis

To further define the HLA-linked genes controlling the susceptibility to Takayasu's arteritis, polymorphisms in five microsatellites around the HLA-B and MICA genes, C1-2-A, MIB, C1-4-1, C1-2-5, and C1-3-1, were investigated in 91 Japanese patients with Takayasu's arteritis and 248 healthy Japanese controls. It was found that allele 238 of C1-2-A [60.4% in patients vs. 29.8% in controls, odds ratio (OR)=3.59, P(c)<0.000004], allele 332 of MIB (22.0% vs. 6. 1%, OR=4.32, P(c)<0.0003), allele 208 of C1-2-5 (47.3% vs. 24.6%, OR=2.75, P(c)=0.001), and allele 291 of C1-3-1 (62.6% vs. 44.8%, OR=2.07, P(c)<0.02) were significantly associated with the disease. Combined analyses of polymorphisms in the HLA-B and MICA genes with those in the microsatellites suggest that there are two different disease-susceptible loci for Takayasu's arteritis; one is mapped near the C1-2-A locus and the other is more closely linked to the HLA-B gene than to the MICA gene, because there are at least two different disease-associated HLA-B haplotypes, HLA-B*52 and -B*39.2 haplotypes, in which the disease-associated C1-2-A allele is shared in common.

Takayasu's arteritis concurrent with Marfan syndrome--a case report

Marfan syndrome (MS) is a dominantly inherited connective tissue disorder characterized by arachnodactyly, tall stature, the presence of aortic aneurysm, and lens dislocation. Takayasu's arteritis (TA) is a chronic vasculitis that primarily affects the aorta and its branches. The authors report the first case of TA in a patient with MS. The simultaneous presence of TA and MS could be a coincidence, however; the pathogenesis of TA might be linked with autoimmunity induced by abnormal extracellular matrix protein derived from the genetic mutations in MS.

Takayasu arteritis: insights into immunopathology

Takayasu arteritis is an acute and sometimes chronic form of vasculitis involving the aorta, its main branches and pulmonary arteries. Although its etiology is still unknown, immunopathologic analyses revealed that the infiltrating cells mainly consisted of gammadelta T-cells as well as alphabeta T-cells and NK cells. The infiltrating gammadelta T-cells, cytotoxic T-lymphocytes (CTLs), and natural killer (NK) cells directly injured the vascular cells by releasing a cytolytic factor, perforin. Expression of heat-shock protein (HSP)-65 as well as human leukocyte antigen (HLA) class I and II was enhanced in Takayasu arteritis lesions, supporting the pathogenic role of gammadelta T-cells and alphabeta T-cells. T-cell receptor (TCR) alphabeta gene usage by the infiltrating cells was restricted, strongly suggesting that a specific antigen was targeted. TCR gammadelta gene usage by the infiltrating cells was also restricted. Furthermore, it has been reported that a strong association with a specific haplotype of major histocompatibility complex (MHC) class I chain-related (MIC), MICA gene with Takayasu arteritis, suggesting that the HLA-linked gene susceptible to the disease is mapped near the MICA gene. This also supports a pathogenic role of gammadelta T-cells in Takayasu arteritis because gammadelta T-cells were shown to recognize MICA molecule, which can be stress-induced. These findings suggest that unknown stress, such as infection, may trigger the autoimmune process of inflammation involved in Takayasu arteritis.

Takayasu's arteritis associated with factor V Leiden

Takayasu's arteritis (TA) is a rare, chronic, and idiopathic vasculitis of the aorta and/or its main branches. There have been case reports of this disease associated with immune hypercoaguable states, namely raised antiphospholipid antibodies. Investigations of the thrombotic nature of Takayasu's arteritis have shown elevated levels of B-thromboglobulin, platelet factor 4, thrombin-antithrombin III complex, and fibrinopeptide A. We report the first case of TA associated with the Factor V Leiden gene defect (Activated Protein C Resistance). The patient is a 30-year-old female who presented with six months of bilateral lower and upper extremity claudication, carotid artery tenderness, diminished brachial pulse and no measurable blood pressure in the left arm, an erythrocyte sedimentation rate (Westergren) of 62 mm/hr, and an angiogram meeting the clinical criteria for TA. Her symptoms showed a dramatic response to high-dose oral glucocorticosteroids and she was also maintained on long-term anticoagulation. This case illustrates that hereditary hypercoagulable states can coexist with acquired vasculitidies and that further investigation into these associations and their pathophysiologic interaction is warranted.

Association of clinical manifestations with HLA-B alleles in Takayasu arteritis

HLA-DNA typing using PCR-SSOP and PCR-DCP methods was performed in 85 patients with Takayasu arteritis and 492 healthy controls who had been typed for HLA by serological method. Frequencies of HLA-B52 (B*5201) and B39 (B*3901 and B*3902) were significantly increased in the patients. Frequency of HLA-DRB1*1502 was also increased but it was suggested to be a reflection of its linkage disequilibrium with B52. Association of HLA-B52 and B39 with seven clinical manifestations--pulmonary infarction, ischemic heart disease, aortic regurgitation, systemic hypertension, renal artery stenosis, cerebrovascular disease, and visual disturbance--in 132 HLA-typed patients with Takayasu arteritis was studied. In HLA-B52 positive TA patients, aortic regurgitation (vs B52(-)-B39(+), OR=3.8, P<0.05, vs B52(-)-B39(-), OR=5.49, P<0.001), ischemic heart disease (vs B52(-)-B39(+), OR=12.05, P<0.05, vs B52(-)-B39(-), OR=2.85, P<0.05), and pulmonary infarction (vs B52(-)-B39(+), OR=5.74, P<0.03) were found to be significantly prevalent. On the other hand, in HLA-B39 positive TA patients, frequency of renal artery stenosis was significantly increased (vs B52(+)-B39(-), OR=12.14, P<0.001, vs B52(-)-B39(-), OR=5.21, P<0.03). These observations have suggested that HLA-B52 molecule and B39 molecule would contribute to different clinical manifestations by binding different antigenic peptides to cause inflammations. Thus HLA-B molecule may play an important role in pathogenesis or determining clinical manifestations of Takayasu arteritis.

MICA gene polymorphism in Takayasu's arteritis and Buerger's disease

To further clarify the HLA-linked genes susceptible to arterio-vasculitis of unknown etiology, Takayasu's arteritis and Buerger's disease, polymorphism in the MICA gene, a newly identified gene near the HLA-B gene and expressed in epithelial cell lineage, was investigated. Polymerase chain reaction (PCR)-DNA conformation polymorphism (DCP) analysis and subsequent sequencing of the MICA gene have revealed that there are 5 MICA alleles which are different in the number of a GCT repeat in exon 5: MICA alleles MICA-1.1, -1.2, -1.3 and -1.4 have 9, 6, 5 and 4 GCT repeats, respectively, and MICA-1.5 has 5 GCT repeats with a 1 bp frameshift insertion in the repeat. MICA genotyping data in 81 Japanese patients with Takayasu's arteritis, 38 Japanese patients with Buerger's disease, and 160 healthy Japanese controls showed that MICA-1.2 and -1.4 were significantly associated with Takayasu's arteritis and Buerger's disease, respectively. Because MICA-1.2 and -1.4 were in strong linkage disequilibria with HLA-B52 and -B54 in the Japanese populations, respectively, we have compared the odds ratio (OR) of the risk to the diseases for individuals having both or each of the disease-associated MICA and HLA-B alleles. It was found that MICA-1.2 gave a significantly high OR of risk to Takayasu's arteritis in the absence of HLA-B52, suggesting that the HLA-linked gene susceptible to Takayasu's arteritis is mapped near the MICA gene. In contrast, MICA-1.4 gave a significantly high OR of risk to Buerger's disease only in the presence of HLA-B54, suggesting that the HLA-linked gene susceptible to Buerger's disease is linked to the HLA-B54-MICA-1.4 haplotype, and may be differently mapped from that to Takayasu's arteritis.

Immunogenetic analysis of Takayasu arteritis in Indian patients

The distribution of HLA-A, B, C and DR antigens was determined in a cohort of 104 unrelated Indian patients with Takayasu arteritis (TA) belonging to the North Indian states of Punjab, Haryana, Uttar Pradesh and Delhi. The data was compared with healthy controls belonging to the same ethnic group. In addition, polymorphism in the MHC class I chain related A (MIC A) gene was studied in a group of 25 TA patients and 40 healthy controls. The data revealed a strong association of the disease with HLA-B5 (chi2=22.5, P<1 x 10(-6), RR=3.08) as well as its two common serological subtypes, B51 (chi2=20.5) and B52 (chi2=18.5). No particular association was observed with any of the five alleles of the MIC A gene, nor any linkage disequilibrium could be established with these alleles and those of HLA-B locus in this population. The observation suggest that HLA linked genes are definitely involved in the development of Takayasu arteritis and that the disease in Indian subjects is associated with HLA-B5 and its two serological subtypes, B51 as well as B52.

Intron 2 and exon 3 sequences may be involved in the susceptibility to develop Takayasu arteritis

We studied Major Histocompatibility Complex (MHC) Class I and Class II genes in seven Mexican Mestizo patients with Takayasu arteritis. Takayasu arteritis is an uncommon condition in Mexican Mestizo, however, previous studies report association of the disease in this population with Human Leukocyte Antigen (HLA)-B39 and HLA-DRB1*1301. The results in the present study show that the haplotypes of the Mexican Mestizo patients with Takayasu arteritis are very heterogeneous, even when the disease is much more rare in Mexico than in Japan. The sequence analysis of HLA-B39 shows that Mexican patients exhibit the HLA-B*39061 and HLA-B*39062 subtypes. These subtypes are more common in Mexico than in Japan, where the predominant subtype is HLA-B*3901. Interestingly, HLA-B*39061 and B-39062 share the 3' end of intron 2 and the 5' end of exon 3 with HLA-B*5101 and B*52012, alleles associated to Takayasu arteritis in Japanese. This fact suggests that Takayasu arteritis patients may share a specific sequence rather than a specific allele, even when the gene involved in the susceptibility to develop Takayasu arteritis may be a neighboring gene located between the genes related at present time with the disease, i.e. a gene located between MHC Class I and Class II regions.

Takayasu arteritis, Buerger disease and inflammatory abdominal aortic aneurysms: is there a common pathway in their pathogenesis?

Takayasu arteritis, Bueger disease and IAAA are non-specific vasculitis involving mainly large vessels, the etiology of which are all still in the mist. Our recent HLA analysis on Takayasu arteritis and Buerger disease revealed a close association with some HLA antigens which made us suppose the common pathological pathway to cause these morbid conditions. International survey on Takayasu arteritis also revealed cases involving abdominal aorta only (Type IV, International Classification) in Asian countries, very similar to clinical and pathological features of IAAA. These ongoing survey suggest the common mechanism in the pathophysiology of these morbid conditions.

Molecular analyses of HLA class II-associated susceptibility to subtypes of autoimmune diseases unique to Asians

It is well known that individuals positive for particular HLA-class II alleles show high risks for the development of Takayasu arteritis and other diseases caused by immunological disorders such as autoimmune diseases and allergies. HLA class II molecules present antigenic peptides to CD4+ T cells. Their extensive polymorphism affects the structures of peptides bound to HLA class II molecules to create individual differences in immune responses to antigenic peptides. To better understand the mechanisms for association between HLA class II alleles and susceptibility to autoimmune diseases, it is important to identify self-peptides presented by disease-susceptible HLA class II molecules and triggering disease-causative T cells. Many autoimmune diseases are observed in all ethnic groups, whereas the incidences of diseases, clinical manifestations and disease-susceptible HLA class II alleles are different among various ethnic groups for some autoimmune diseases. These phenomena suggest that differences in autoimmune self-peptide(s) in the context of disease-susceptible HLA class II molecules may cause these differences. Therefore, comparisons among disease-susceptible HLA class II alleles, autoimmune self-peptides and clinical manifestations of autoimmune diseases in different ethnic groups would be helpful in determining the pathogenesis of the diseases. In this paper, we describe our recent findings on: (1) the uniqueness of both clinical manifestations and HLA-linked genetic background of Asian-type (optico-spinal form) multiple sclerosis; (2) the structural characteristics of peptides bound to HLA-DQ molecules susceptible to insulin-dependent diabetes mellitus; (3) the identification of a disease-related autoantigenic peptide presented by disease-susceptible HLA-DQ molecules in Asians-specific infant onset myasthenia gravis; and (4) a manipulation of human T cell response by altered peptide ligands, as a possible candidate for new and antigen-specific immuno-suppressive therapy against autoimmune diseases.

A patient with familial Takayasu's arteritis presenting with fever of unknown origin

Takayasu's arteritis rarely presents with fever of unknown origin. We describe a 14-year-old girl who was admitted with a 2-month history of fever of unknown origin associated with vague pain in her left upper arm. The constitutional symptoms responded to a trial of steroid therapy for suspected collagen-vascular disease, but flared up when the dose was tapered. An asymmetric radial pulse was recognized incidentally during follow-up examination; diagnosis of Takayasu's arteritis was confirmed by Duplex ultrasonography and angiography. Takayasu's arteritis must be considered when evaluating children with fever of unknown origin, especially those with a positive family history. Careful assessment of the peripheral vascular system with better interpretation of limb symptoms should allow early, appropriate treatment to prevent irreversible vascular damage.