Identification of susceptibility loci for Takayasu arteritis through a large multi-ancestral genome-wide association study.

Takayasu arteritis is a rare inflammatory disease of large arteries. We performed a genetic study in Takayasu arteritis comprising 6,670 individuals (1,226 affected individuals) from five different populations. We discovered HLA risk factors and four non-HLA susceptibility loci in VPS8, SVEP1, CFL2, and chr13q21 and reinforced IL12B, PTK2B, and chr21q22 as robust susceptibility loci shared across ancestries. Functional analysis proposed plausible underlying disease mechanisms and pinpointed ETS2 as a potential causal gene for chr21q22 association. We also identified >60 candidate loci with suggestive association (p < 5 × 10-5) and devised a genetic risk score for Takayasu arteritis. Takayasu arteritis was compared to hundreds of other traits, revealing the closest genetic relatedness to inflammatory bowel disease. Epigenetic patterns within risk loci suggest roles for monocytes and B cells in Takayasu arteritis. This work enhances understanding of the genetic basis and pathophysiology of Takayasu arteritis and provides clues for potential new therapeutic targets.

Efficacy of convalescent plasma therapy in severe COVID-19 patients.

INTRODUCTION: The use of convalescent plasma (CP) transfusions is very valuable in the current COVID-19 outbreak, given that there are no specific preventive and therapeutic options. MATERIALS AND METHODS: 50 patients with severe COVID-19 disease treated with convalescent plasma transfusion were included in the study. The efficacy of CP and in which situations it was effective were investigated. CONCLUSION: 80 % of the patients recovered, and 20 % died in our study. The mean age of the patients who died was found to be higher than the patients who recovered. CRP, ferritin, D-dimer, neutrophil, MPV, and NLR counts were found to be higher, and lymphocyte and platelet counts were lower in the deceased group after CP. It was determined that patients who received CP within the first five days were hospitalized for a shorter period. DISCUSSION: Administration of CP transfusion within the first five days in severe COVID-19 patients has been shown to reduce hospital stay length.

Identification of multiple genetic susceptibility loci in Takayasu arteritis.

Takayasu arteritis is a rare inflammatory disease of large arteries. The etiology of Takayasu arteritis remains poorly understood, but genetic contribution to the disease pathogenesis is supported by the genetic association with HLA-B*52. We genotyped ~200,000 genetic variants in two ethnically divergent Takayasu arteritis cohorts from Turkey and North America by using a custom-designed genotyping platform (Immunochip). Additional genetic variants and the classical HLA alleles were imputed and analyzed. We identified and confirmed two independent susceptibility loci within the HLA region (r(2) < 0.2): HLA-B/MICA (rs12524487, OR = 3.29, p = 5.57 × 10(-16)) and HLA-DQB1/HLA-DRB1 (rs113452171, OR = 2.34, p = 3.74 × 10(-9); and rs189754752, OR = 2.47, p = 4.22 × 10(-9)). In addition, we identified and confirmed a genetic association between Takayasu arteritis and the FCGR2A/FCGR3A locus on chromosome 1 (rs10919543, OR = 1.81, p = 5.89 × 10(-12)). The risk allele in this locus results in increased mRNA expression of FCGR2A. We also established the genetic association between IL12B and Takayasu arteritis (rs56167332, OR = 1.54, p = 2.18 × 10(-8)).

A novel recessive 15-hydroxyprostaglandin dehydrogenase mutation in a family with primary hypertrophic osteoarthropathy.

We present two PHO siblings having a novel homozygous truncating mutation in HPGD. The purpose of the study was to attempt medical treatment, and to find the HPGD mutation causing the disease, in a 22-year old Turkish male and his 23-year old sister afflicted with primary hypertrophic osteoarthropathy (PHO). In combination with NSAIDs and colchicine, treatment with sulfasalazine was started in both cases, and methotrexate was added to the treatment regimen of the female patient at the end of the first year. The patients were found to be typical PHO. Ultrasonographic examination of the joints revealed synovitis and inflammation by B mode and power Doppler ultrasonography. Joint symptoms responded to sulfasalazine treatment in both patients. However, after the addition of methotrexate, the female patient had better remission. All exons of HPGD, the known disease gene, were analyzed by Sanger sequencing. A homozygous 2-bp deletion (c.310_311delCT or p.L104AfsX3) was identified. Seven relatives carrying the mutation in the heterozygous state were examined and none was found affected. Although not specific for this disease, skin, soft tissue and joint ultrasonography can be helpful for evaluation of the musculoskeletal findings in the patients.

Are monocyte-to-HDL and C-reactive protein-to-albumin ratios useful for the diagnosis and follow-up of Takayasu arteritis?

OBJECTIVE: In this study, we aimed to investigate the role of erythrocyte sedimentation rate, C-reactive protein, neutrophil/lymphocyte ratio, platelet/lymphocyte ratio, monocyte/lymphocyte ratio, red blood cell distribution width, mean platelet volume, monocyte/HDL ratio, and C-reactive protein/albumin ratio in the diagnosis and treatment follow-up of active and remission Takayasu arteritis patients compared with healthy control group. METHODS: This is a retrospective case-control study in which 56 Takayasu arteritis patients and 40 age- and sex-matched healthy control were included. The blood values of Takayasu arteritis patients were analyzed during their active period and post-treatment remission periods, after comparing them with the healthy control. Furthermore, all parameters were evaluated by receiver operating characteristic analysis. RESULTS: Erythrocyte sedimentation rate, C-reactive protein, neutrophil/lymphocyte ratio, platelet/lymphocyte ratio, monocyte/lymphocyte ratio, monocyte/HDL ratio, and C-reactive protein/albumin ratio values were significantly higher in active Takayasu arteritis patients compared with healthy control and remission Takayasu arteritis groups. In the receiver operating characteristic analysis performed in active Takayasu arteritis and Takayasu arteritis patients in remission, C-reactive protein had the highest power to indicate disease activity, followed by C-reactive protein/albumin ratio, erythrocyte sedimentation rate, and monocyte/HDL ratio. When Takayasu arteritis in remission was compared with the healthy control, a significant difference was found between erythrocyte sedimentation rate, C-reactive protein, red blood cell distribution width, and C-reactive protein/albumin ratio, while no significant difference was found between monocyte/HDL ratio values. CONCLUSION: C-reactive protein/albumin ratio and red blood cell distribution width can be used in the diagnosis of Takayasu arteritis, and C-reactive protein/albumin ratio, red blood cell distribution width, and monocyte/HDL ratio measurements can be used in the follow-up. As C-reactive protein/albumin ratio is more powerful than C-reactive protein in differentiating the Takayasu arteritis group from the healthy control group, evaluation of C-reactive protein/albumin ratio together with albumin instead of evaluation of C-reactive protein alone when diagnosing the disease may help us to obtain more accurate results in daily practice.

Serum eosinophil cationic protein levels in Behçet's disease and its relation to clinical activity.

BACKGROUND: Eosinophil cationic protein (ECP) is a matrix protein of eosinophils and has been reported to reflect eosinophil activity. Few studies have examined the role of eosinophils in the pathogenesis of Behçet's disease. OBJECTIVE: The purpose of the present study was to investigate the serum ECP levels in BD and its relation to clinical activity. METHODS: Forty-seven consecutive patients with BD (22 active, 25 inactive), 21 age and sex matched patients with allergic rhinitis and 21 healthy controls were evaluated cross-sectionally. The serum ECP levels were measured by the flourescein enzyme immunoassay method. RESULTS: Mean serum ECP levels of active patients with BD (34.28 ± 23.43 µg/L) were found to be significantly lower than those of the inactive patients (65.69 ± 46.32 µg/L, p <0.05) and the controls (62.92 ± 30.49 µg/L, p <0.01) . Behçet patients with oral aphthous lesions had significantly lower mean serum ECP levels (n=21, 38.82 ± 33.38 µg/L) than those without aphthous lesions (n=26, 60.81 ± 43.21µg/L) (p = 0.041). Similarly patients with arthritis had lower serum ECP values (n=6, 22.12 ± 9.47 µg/L) than those without arthritis (n = 41, 55.21 ± 41.35 µg/L) (p =0.029). CONCLUSIONS: Lower ECP levels in the active phase of the disease may be a result of decreased production due to the activation of Th1 cytokines.

Evaluation of renewable energy policies in Turkey with sectoral electricity demand forecasting.

Energy is an essential requirement for sustainable development, society, and the world. Turkey has been trying to increase the use of renewable sources in electricity energy production with the incentive policies it has implemented in recent years. Accordingly, in the 2019-2023 Strategic Plan of the Ministry of Energy and Natural Resources, targets to increase the installed capacity of renewable energy sources have been determined. In this context, this article examines fort the first time, the effect of installed capacity of renewable energy sources on sectoral electricity demand. Thus, the study aims to evaluate the renewable energy policies implemented in Turkey. For this purpose, firstly, sectoral electricity demands were estimated for the period 1988-2017 using the autoregressive distributed lag bound testing approach. Then, forecasts were made for the period 2019-2023 with the econometric simulation method. The findings show that the Installed Capacity variable significantly and negatively affects electricity demand in all sectors in the long run. According to the forecast results made in the second stage of the study, it was observed that the higher the increase rate in the installed capacity of renewable energy sources, the faster the electricity demand would decrease. According to these results, Turkey needs to increase the share of renewable energy sources in electricity production in terms of economic and environmental sustainability.

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.

Assessment of disease activity and progression in Takayasu's arteritis with Disease Extent Index-Takayasu.

OBJECTIVE: Disease Extent Index-Takayasu (DEI.Tak) is a new index developed for the follow-up of Takayasu's arteritis (TA), assessing only clinical findings without the requirement of imaging. We investigated the effectiveness of DEI.Tak in assessing disease activity and progression by comparing with physician's global assessment (PGA) and active disease criteria defined by Kerr et al. METHODS: The initial DEI.Tak forms were filled in for 145 TA patients cross-sectionally to detect the baseline damage and after 29.8 (31) months (n = 105, 144 visits) only by including the new/worsening symptoms within the past 6 months. RESULTS: At baseline, all patients had a DEI.Tak >0 [mean (s.d.): 7.6 (4.2)]. At this evaluation, 62% of the patients had active, 16.2% had persistent and 21.8% had inactive disease according to the PGA. At follow-up, in 69% of the patients the DEI.Tak score was 0. However, 14% of them were accepted as having active and 17% persistent disease according to PGA. In contrast, 18% with a DEI.Tak ≥ 1 were inactive according to PGA. Patients with active or persistent disease with PGA had higher DEI.Tak compared with inactives [1.3 (1.9), 1 (1.3) vs 0.2 (0.6), respectively; P < 0.001]. According to Kerr's criteria 27% were active. The total agreement between DEI.Tak and Kerr's criteria was 94% (κ = 0.85). Compared with PGA, Kerr's criteria had a total agreement of 74% and DEI.Tak 68%. CONCLUSION: During follow-up, most TA patients showed no clinical activity with DEI-Tak. Although the agreement between Kerr's criteria and DEI.Tak seemed very good, using Kerr's criteria instead of DEI.Tak increased the consistency with PGA, which could be explained by the influence of imaging data and acute-phase reactant levels on the physician's decisions.

Renal injury due to hepatic hydatid disease.

BACKGROUND: Many studies on renal hydatid disease have been reported in the literature, and the disease process appears to be well defined. However, renal injury without direct renal invasion remains poorly understood. The present study aims to define the frequency and the property of the renal involvement in hydatid disease. METHODS: Eighty patients older than 18 years and diagnosed with liver echinococcosis were included in the study. The echinococcosis was diagnosed by the haemagglutination test and abdominal ultrasonography. Twenty-four-hour protein excretion was measured for patients who had elevated serum creatinine levels or whose urinalyses were positive for haematuria or proteinuria. Subsequently, renal biopsy was performed, and the specimens were examined by light microscopy and immunofluorescence staining. RESULTS: Haematuria was detected in 11 patients (13.75%), and proteinuria was detected in nine patients (11.25%). Percutaneous renal biopsy was applied to nine patients who gave signed consents to undergo the test. We detected four immunoglobulin A nephritis (together with tubulointerstitial nephritis in one patient), one membranoproliferative glomerulonephritis, one immunoglobulin M nephritis together with mesangiocapillary glomerulonephritis, one membranous glomerulonephritis, one amyloidosis and one tubulointerstitial nephritis. Renal hydatid cyst was detected only in four patients (5%). CONCLUSIONS: Hydatid disease, which affects the kidney, is not rare, and we suggest that urinalysis and, if indicated, renal biopsy should be performed for hepatic hydatid disease diagnosis.

Investigation of C5a receptor gene 450 C/T polymorphism in Turkish patients with familial Mediterranean fever.

Familial Mediterranean fever (FMF) is a genetic disorder with acute inflammatory serosal attacks due to MEFV gene mutations which resides in chromosome 16. Lack of a C5a inhibitor activity in the peritoneum has previously been proposed in part to contribute in propagation of the serosal inflammation in FMF attacks. The aim of this study is to investigate C5a receptor (C5aR) gene polymorphism in patients with FMF and its relation to the main features of the disease. A polymorphism in the coding region of C5aR gene leading to C to T transition at nucleotide position 450 has been investigated in 85 non-related Turkish FMF patients and 160 non-related healthy controls by using PCR-RFLP. The frequencies of C5aR gene 450 CT genotype and T allele were not significantly different between Turkish FMF patients and healthy subjects (14.12 and 8.24% for FMF vs. 10 and 5% for controls, respectively). C5aR gene 450 CT genotype tended to associate with the presence Henoch-Schonlein purpura (OR: 1.25, 95% CI: 0.917-1.704, P = 0.017) but with no other clinical findings of the disease. C5aR polymorphism might be searched in populations having high prevalence of FMF.

Are monocyte-to-HDL and C-reactive protein-to-albumin ratios useful for the diagnosis and follow-up of Takayasu arteritis?

SUMMARY OBJECTIVE: In this study, we aimed to investigate the role of erythrocyte sedimentation rate, C-reactive protein, neutrophil/lymphocyte ratio, platelet/lymphocyte ratio, monocyte/lymphocyte ratio, red blood cell distribution width, mean platelet volume, monocyte/HDL ratio, and C-reactive protein/albumin ratio in the diagnosis and treatment follow-up of active and remission Takayasu arteritis patients compared with healthy control group. METHODS: This is a retrospective case-control study in which 56 Takayasu arteritis patients and 40 age- and sex-matched healthy control were included. The blood values of Takayasu arteritis patients were analyzed during their active period and post-treatment remission periods, after comparing them with the healthy control. Furthermore, all parameters were evaluated by receiver operating characteristic analysis. RESULTS: Erythrocyte sedimentation rate, C-reactive protein, neutrophil/lymphocyte ratio, platelet/lymphocyte ratio, monocyte/lymphocyte ratio, monocyte/HDL ratio, and C-reactive protein/albumin ratio values were significantly higher in active Takayasu arteritis patients compared with healthy control and remission Takayasu arteritis groups. In the receiver operating characteristic analysis performed in active Takayasu arteritis and Takayasu arteritis patients in remission, C-reactive protein had the highest power to indicate disease activity, followed by C-reactive protein/albumin ratio, erythrocyte sedimentation rate, and monocyte/HDL ratio. When Takayasu arteritis in remission was compared with the healthy control, a significant difference was found between erythrocyte sedimentation rate, C-reactive protein, red blood cell distribution width, and C-reactive protein/albumin ratio, while no significant difference was found between monocyte/HDL ratio values. CONCLUSION: C-reactive protein/albumin ratio and red blood cell distribution width can be used in the diagnosis of Takayasu arteritis, and C-reactive protein/albumin ratio, red blood cell distribution width, and monocyte/HDL ratio measurements can be used in the follow-up. As C-reactive protein/albumin ratio is more powerful than C-reactive protein in differentiating the Takayasu arteritis group from the healthy control group, evaluation of C-reactive protein/albumin ratio together with albumin instead of evaluation of C-reactive protein alone when diagnosing the disease may help us to obtain more accurate results in daily practice.

Reactive arthritis due to zoophilic (canine) sexual intercourse.

Reactive arthritis (ReA) is defined as a joint inflammation triggered by a distant infection, with no cultivable microbes in the joints. Although efforts have been made to characterize the microorganism linked to ReA, no definite common feature has so far emerged. Here we present a case of ReA which occurred after a zoophilic (canine genus) sexual intercourse.

Evaluation of the Turkish version of the Bath Ankylosing Spondylitis Patient Global Score (BAS-G).

The objective of this study was to investigate the reliability and validity of the Turkish version of the Bath Ankylosing Spondylitis (AS) Patient Global Score (BAS-G). Seventy-one consecutive patients with AS were enrolled into the study. Patients were requested to fill in the questionnaire on the day of admission (first visit), on a second occasion within 24 h after admission (second visit) for test-retest reliability analysis, and on a third occasion for assessing sensitivity to change. Construct validity was assessed by correlation analysis with the Bath AS Functional Index (BASFI), Dougados Functional Index (DFI), Dougados Articular Index (DAI), physical examination findings, and several other parameters. Test-retest reliability analysis of individual BAS-G scores at initial and second visits showed good intraclass correlations [n=46, intraclass correlation=0.928 (0.870-0.960) and intraclass correlation=0.853 (0.725-0.920), for 1-week and 6-month scores, respectively]. Both 1-week and 6-month scores showed moderate correlations with the BASFI (r=0.586 and r=0.503, respectively, P=0.000 for both). The 1-week score also showed moderate correlation with the DFI (r=0.530, P=0.000). The 1-week score showed weak correlations with finger-to-floor distance (r=0.263, P=0.027), chest expansion (r=-0.245, P=0.039), and DAI (r=0.271, P=0.036). Change in the 1-week score at the third visit showed good correlation with the BASFI score (r=0.670, P=0.000, n=36) and moderate correlation with the DFI (r=0.440, P=0.017, n=29). The Turkish version of the BAS-G has good reliability and validity. It is a good tool for assessing patients with AS or other rheumatic diseases in clinical practice and research.

The effects of scalpel, harmonic scalpel and monopolar electrocautery on the healing of colonic anastomosis after colonic resection.

PURPOSE: In our study, the effects of harmonic scalpel, scalpel, and monopolar electrocautery usage on the health and healing of colon anastomosis after resection was investigated. METHODS: In this study, 120 female albino Wistar rats were divided into 3 groups each containing 40 rats. Group A, resection with scalpel; group B, resection with monopolar electrocautery; group C, resection with harmonic scalpel. The groups were divided into 4 subgroups consisting of 10 rats and analysed in the postoperative 1st, 3rd, 5th, and 7th days. Anastomotic bursting pressures, hydroxyproline levels and histopathological parameters were surrogate parameters for evaluating wound healing. RESULTS: The tissue hydroxyproline levels did not show any significant difference between the groups and subgroups. The mean bursting pressure of group A on the 5th day was significantly higher than groups B and C (P < 0.001). When the fibroblast and fibrosis scores were evaluated, scores of group C on the 5th day were significantly higher than the other groups, but the results of bursting pressures and biochemical parameters did not support the fibroblast and fibrosis scores. There were not any significant differences between the groups in other histopathologic parameters. CONCLUSION: The use of monopolar electrocautery needs more attention since the device causes tissue destruction. The obliterating effect of harmonic scalpel on luminal organs is an important problem, especially if an anastomosis is planned. Despite the disadvantages of scalpel, its efficacy on early wound healing is better than the other devices.

Comparison of amplification refractory mutation system and polymerase chain reaction-restriction fragment length polymorphism techniques used for the investigation of MEFV gene exon 10 point mutations in familial Mediterranean fever patients living in Cukurova region (Turkey).

Familial Mediterranean fever (FMF) is an autosomal recessive inherited disease characterized by recurrent fever, serositis and arthritis. The disease is highly prevalent in Mediterranean basin populations. Recently, the gene responsible for FMF (MEFV) was cloned and at least 40 MEFV gene mutations have been identified. The most frequently observed mutations in the MEFV gene are M694V, M694I, M680I, and V726A. These occur within exon 10 of the gene, and account for 85% of the known MEFV alleles. In this study, the reliability and economical aspects of amplification refractory mutation system (ARMS) and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) techniques were compared for analyzing the frequencies of the major point mutations of 90 unrelated patients with FMF from the Cukurova region in Turkey. Both techniques yielded similar results: The ratio of independent alleles of 90 patients carrying one of the tested mutations was 81.1%; patients consisted of 12 different genotypes. In 64 of 90 patients (71.1%) mutations were observed in both alleles. Thirty-six patients (40%) were homozygous for the same mutation, 28 (31.1%) were heterozygous for different mutations. Eighteen patients (20%) were heterozygous for one allele with one of the four mutations but the other allele was unknown. In 8 patients (8.8%) no mutation could be detected. The most frequently observed mutation was M694V (51.66%), followed by M680I (17.22%), V726A (10.55%), and M694I (1.66%). In conclusion ARMS and PCR-RFLP techniques were equally reliable to detect the mutations in Turkish FMF patients. However, the ARMS technique was found to be more rapid and economical than the PCR-RFLP techniques.

The Turkish version of the Bath Ankylosing Spondylitis Functional Index: reliability and validity.

The purpose of this study was to investigate the reliability and validity of the Turkish version of the Bath Ankylosing Spondylitis (AS) Functional Index (BASFI). The Turkish version of the BASFI was obtained after a process of translation and back-translation. Eighty-one consecutive patients meeting the 1984 New York criteria for AS were enrolled. Patients were evaluated and requested to complete the questionnaire at days 1 and 2 and on a third occasion between days 15-90. Reliability, reproducibility, validity and sensitivity to change of the Turkish version of the index were assessed. Each score correlated closely with the index score, with coefficients between 0.727 and 0.844. Reliability analysis showed a Cronbach's alpha score of 0.926. Correlations were found between all items of the BASFI and Schober's test (r=-0.258 to -0.531, p<0.001-0.05), occiput-to-wall distance (r=0.284 and 0.589, p<0.001-0.05), and finger-to-floor distance (r=0.334 to 0.613, p<0.001-0.01). The total index score was correlated with the number of nocturnal awakenings (r=0.515, p<0.001), Schober's test (r=-0.444, p<0.001), finger-to-floor distance (r=0.567, p<0.001), occiput-to-wall distance (r=0.535, p<0.001), chest expansion (r=-0.403, p<0.001), and the Dougados articular index (r=0.371, p<0.01). A good correlation was found between day 0 and 1 BASFI indices (r=0.765-0.917, p<0.001), showing good reproducibility of the index. The Turkish version of the BASFI showed reliability, reproducibility, and validity, confirming its utility in the research of AS in Turkey. However, sensitivity to changes due to drug therapy and/or rehabilitation remains to be determined.

Assessment of Patients with Takayasu Arteritis in Routine Practice with Indian Takayasu Clinical Activity Score.

OBJECTIVE: To assess the Indian Takayasu Clinical Activity Score (ITAS2010) in followup of Takayasu arteritis (TA). METHODS: ITAS2010 forms were filled in prospectively (n = 144). Clinical activity was assessed with physician's global assessment (PGA) and criteria defined by Kerr, et al. RESULTS: ITAS2010 was significantly higher in patients with active disease. Total agreement between ITAS2010 and PGA was 66.4%, and between ITAS2010 and Kerr, et al was 82.8%. During followup, 14 of 15 patients showing vascular progression with imaging were categorized as having inactive disease according to ITAS2010. CONCLUSION: ITAS2010 was discriminatory for activity during the followup, but the agreement between PGA and ITAS2010 was moderate. Future work should include the incorporation of advanced vascular imaging and demonstration of ITAS2010 as a scalable measure and not simply a dichotomous measure of activity/flare versus remission.

Identification of Susceptibility Loci in IL6, RPS9/LILRB3, and an Intergenic Locus on Chromosome 21q22 in Takayasu Arteritis in a Genome-Wide Association Study.

OBJECTIVE: Takayasu arteritis is a rare large vessel vasculitis with incompletely understood etiology. This study was undertaken to perform the first unbiased genome-wide association analysis of Takayasu arteritis. METHODS: Two independent cohorts of patients with Takayasu arteritis from Turkey and North America were included in our study. The Turkish cohort consisted of 559 patients and 489 controls, and the North American cohort consisted of 134 patients and 1,047 controls of European ancestry. Genotyping was performed using the Omni1-Quad and Omni2.5 genotyping arrays. Genotyping data were subjected to rigorous quality control measures and subsequently analyzed to discover genetic susceptibility loci for Takayasu arteritis. RESULTS: We identified genetic susceptibility loci for Takayasu arteritis with a genome-wide level of significance in IL6 (rs2069837) (odds ratio [OR] 2.07, P = 6.70 × 10(-9)), RPS9/LILRB3 (rs11666543) (OR 1.65, P = 2.34 × 10(-8)), and an intergenic locus on chromosome 21q22 (rs2836878) (OR 1.79, P = 3.62 × 10(-10)). The genetic susceptibility locus in RPS9/LILRB3 lies within the leukocyte receptor complex gene cluster on chromosome 19q13.4, and the disease risk variant in this locus correlates with reduced expression of multiple genes including the inhibitory leukocyte immunoglobulin-like receptor gene LILRB3 (P = 2.29 × 10(-8)). In addition, we identified candidate susceptibility genes with suggestive levels of association (P < 1 × 10(-5)) with Takayasu arteritis, including PCSK5, LILRA3, PPM1G/NRBP1, and PTK2B. CONCLUSION: Our findings indicate novel genetic susceptibility loci for Takayasu arteritis and uncover potentially important aspects of the pathophysiology of this form of vasculitis.