Identification of novel genetic susceptibility loci for Behçet's disease using a genome-wide association study

Introduction Behcet's disease is a chronic systemic inflammatory disease that remains incompletely understood. Herein, we perform the first genome-wide association study in Behcet's disease

Assessment of Disease Activity in Large-vessel Vasculitis: Results of an International Delphi Exercise.

OBJECTIVE: To arrive at consensus for candidate outcomes for disease activity assessment in large-vessel vasculitis (LVV) in clinical trials. METHODS: A Delphi survey including 99 items was circulated among international experts for 3 rounds. RESULTS: Fifty-seven items were accepted for both giant cell arteritis and Takayasu arteritis. Sixty-seven percent of experts voted to have a common approach for both diseases with additional disease-specific items such as weight loss, scalp tenderness/necrosis, morning stiffness, dizziness, visual symptoms, and imaging. CONCLUSION: This study highlights similarities and differences in experts' perspectives for assessing clinical activity in LVV and may guide a consensus-driven core set of validated outcomes

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ABSTRACT. Objective. To compare the Quantiferon-TB Gold test (QTF-G) with the tuberculin skin test (TST) for the detection of latent tuberculosis infection (LTBI) among patients with rheumatoid arthritis (RA) and ankylosing spondylitis (AS), with reevaluation of the patients treated with tumor necrosis factor-α (TNF-α) antagonists in the followup. Methods. The study involved 140 consecutive patients, 82 with RA and 58 with AS. Thirty patients were evaluated with QTF-G for detection of LTBI before and after 6 months of TNF-α antagonist treatment. QTF-G was also performed on 49 healthy controls. QTF-G results were recorded as positive, negative, or indeterminate. A positive TST was defined as ≥ 5 mm for RA and AS. Results. The percentages of positive QTF-G were comparable in RA and AS (37% vs 32%). The rate of positive QTF-G in healthy controls (29%) was also similar to RA and AS. In contrast to QTF-G results, a high rate of TST positivity was observed in AS compared to RA (82% vs 55%; p = 0.02). The total agreement between QTF-G and TST was observed to be 61% (κ = 0.29) in the whole group, 70% (κ = 0.42) in RA, and 49% (κ = 0.14) in AS. After 6 months of treatment with TNF-α antagonists, a high rate of QTF-G change was observed in patients with indeterminate results (23% vs 3%; p = 0.03)

Agreement between quantiferon-TB gold test and tuberculin skin test in the identification of latent tuberculosis infection in patients with rheumatoid arthritis and ankylosing spondylitis

ABSTRACT. Objective. To compare the Quantiferon-TB Gold test (QTF-G) with the tuberculin skin test (TST) for the detection of latent tuberculosis infection (LTBI) among patients with rheumatoid arthritis (RA) and ankylosing spondylitis (AS), with reevaluation of the patients treated with tumor necrosis factor-α (TNF-α) antagonists in the followup. Methods. The study involved 140 consecutive patients, 82 with RA and 58 with AS. Thirty patients were evaluated with QTF-G for detection of LTBI before and after 6 months of TNF-α antagonist treatment. QTF-G was also performed on 49 healthy controls. QTF-G results were recorded as positive, negative, or indeterminate. A positive TST was defined as ≥ 5 mm for RA and AS. Results. The percentages of positive QTF-G were comparable in RA and AS (37% vs 32%). The rate of positive QTF-G in healthy controls (29%) was also similar to RA and AS. In contrast to QTF-G results, a high rate of TST positivity was observed in AS compared to RA (82% vs 55%; p = 0.02). The total agreement between QTF-G and TST was observed to be 61% (κ = 0.29) in the whole group, 70% (κ = 0.42) in RA, and 49% (κ = 0.14) in AS. After 6 months of treatment with TNF-α antagonists, a high rate of QTF-G change was observed in patients with indeterminate results (23% vs 3%; p = 0.03)

Whole Exome Sequencing Identifies Rare Protein-Coding Variants in Behçet's Disease

Behçet's disease (BD) is a systemic inflammatory disease with an incompletely understood etiology. Despite the identification of multiple common genetic variants associated with BD, rare genetic variants have been less explored. We undertook this study to investigate the role of rare variants in BD by performing whole exome sequencing in BD patients of European descent. METHODS: Whole exome sequencing was performed in a discovery set comprising 14 German BD patients of European descent. For replication and validation, Sanger sequencing and Sequenom genotyping were performed in the discovery set and in 2 additional independent sets of 49 German BD patients and 129 Italian BD patients of European descent. Genetic association analysis was then performed in BD patients and 503 controls of European descent. Functional effects of associated genetic variants were assessed using bioinformatic approaches. RESULTS: Using whole exome sequencing, we identified 77 rare variants (in 74 genes) with predicted protein-damaging effects in BD. These variants were genotyped in 2 additional patient sets and then analyzed to reveal significant associations with BD at 2 genetic variants detected in all 3 patient sets that remained significant after Bonferroni correction. We detected genetic association between BD and LIMK2 (rs149034313), involved in regulating cytoskeletal reorganization, and between BD and NEIL1 (rs5745908), involved in base excision DNA repair (P = 3.22 × 10(-4) and P = 5.16 × 10(-4) , respectively). The LIMK2 association is a missense variant with predicted protein damage that may influence functional interactions with proteins involved in cytoskeletal regulation by Rho GTPase, inflammation mediated by chemokine and cytokine signaling pathways, T cell activation, and angiogenesis (Bonferroni-corrected P = 5.63 × 10(-14) , P = 7.29 × 10(-6) , P = 1.15 × 10(-5) , and P = 6.40 × 10(-3) , respectively). The genetic association in NEIL1 is a predicted splice donor variant that may introduce a deleterious intron retention and result in a noncoding transcript variant. CONCLUSION: We used whole exome sequencing in BD for the first time and identified 2 rare putative protein-damaging genetic variants associated with this disease. These genetic variants might influence cytoskeletal regulation and DNA repair mechanisms in BD and might provide further insight into increased leukocyte tissue infiltration and the role of oxidative stress in BD

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

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