Seven-chain adaptive immune receptor repertoire analysis in rheumatoid arthritis reveals novel features associated with disease and clinically relevant phenotypes.

Background: In rheumatoid arthritis (RA), the activation of T and B cell clones specific for self-antigens leads to the chronic inflammation of the synovium. Here, we perform an in-depth quantitative analysis of the seven chains that comprise the adaptive immune receptor repertoire (AIRR) in RA.

Results: In comparison to controls, we show that RA patients have multiple and strong differences in the B cell receptor repertoire including reduced diversity as well as altered isotype, chain, and segment frequencies.

Characterising the axial phenotype of psoriatic arthritis: a study comparing axial psoriatic arthritis and ankylosing spondylitis with psoriasis from the REGISPONSER registry.

Aims: To explore the clinical and radiographical characteristics of axial psoriatic arthritis (PsA) and to compare it with ankylosing spondylitis (AS) with psoriasis.

Methods: Cross-sectional study from the national multicentre registry REGISPONSER where participants fulfilled the European Spondyloarthropathy Study Group spondyloarthritis criteria at entry. Clinical, laboratory and radiographical characteristics between patients classified as axial PsA and AS with psoriasis by their rheumatologist are compared according to HLA-B27 status.

Interactions between rheumatoid arthritis antibodies are associated with the response to anti-tumor necrosis factor therapy.

Background: Blocking of the Tumor Necrosis Factor (TNF) activity is a successful therapeutic approach for 50-60% of rheumatoid arthritis (RA) patients. However, there are yet no biomarkers to stratify patients for anti-TNF therapy. Rheumatoid factor (RF) and anti-cyclic-citrullinated antibodies (anti-CCP) have been evaluated as biomarkers of response but the results have shown limited consistency.

Incidence of COVID-19 in a cohort of adult and paediatric patients with rheumatic diseases treated with targeted biologic and synthetic disease-modifying anti-rheumatic drugs.

Objectives: To investigate the incidence of COVID-19 in a cohort of adult and paediatric patients with rheumatic diseases receiving targeted biologic and synthetic disease modifying anti-rheumatic drugs (tDMARDs) and to explore the possible effect of these treatments in the clinical expression of COVID-19.

Methods: A cross-sectional study comprising of a telephone survey and electronic health records review was performed including all adult and paediatric patients with rheumatic diseases treated with tDMARDs in a large rheumatology tertiary centre in Barcelona, Spain. Demographics, disease activity, COVID-19 related symptoms and contact history data were obtained from the start of the 2020 pandemic.

Leishmaniasis and tumor necrosis factor alpha antagonists in the Mediterranean basin. A switch in clinical expression.

Background: Tumor necrosis factor alpha (TNF-α) blockers are recognized as a risk factor for reactivation of granulomatous infections. Leishmaniasis has been associated with the use of these drugs, although few cases have been reported.

Methodology: We performed a retrospective observational study including patients with confirmed leishmaniasis acquired in the Mediterranean basin that were under TNF-α blockers therapy at the moment of the diagnosis.

Measuring inflammation in rheumatoid arthritis with a new clinical and ultrasound index: development and initial validation.

With the aim to develop and validate a clinical + ultrasound (US) inflammation score in rheumatoid arthritis (RA) for use in clinical practice, a mixed-method study was conducted. The theoretical development of the index was achieved with qualitative methodology (discussion group and Delphi survey). Subsequently, a cross-sectional study was carried out to analyse issues related to scoring and validation of the new index.

A Combined Transcriptomic and Genomic Analysis Identifies a Gene Signature Associated With the Response to Anti-TNF Therapy in Rheumatoid Arthritis.

Rheumatoid arthritis (RA) is the most frequent autoimmune disease involving the joints. Although anti-TNF therapies have proven effective in the management of RA, approximately one third of patients do not show a significant clinical response. The objective of this study was to identify new genetic variation associated with the clinical response to anti-TNF therapy in RA.

Genetic variation at the glycosaminoglycan metabolism pathway contributes to the risk of psoriatic arthritis but not psoriasis.

Objective: Psoriatic arthritis (PsA) is a chronic inflammatory arthritis affecting up to 30% of patients with psoriasis (Ps). To date, most of the known risk loci for PsA are shared with Ps, and identifying disease-specific variation has proven very challenging. The objective of the present study was to identify genetic variation specific for PsA.

Concordance between direct and indirect measurements of free 25-OH vitamin D.

Unlabelled: At present, data comparing the quantification methods for measurement of free vitamin D (direct assay [direct 25-OHD] and estimated by calculation [calculated 25-OHD]), are scarce. The aim of this study was to analyse the concordance between these two methods of 25-OHD analysis (direct vs. calculated).

Association Between Vitamin D Status and Schizophrenia: A First Psychotic Episode Study.

Vitamin D deficiency has been linked with schizophrenia. We aimed to determine whether patients with a first episode of psychosis (FEP) had lower vitamin D levels compared with controls considering their final diagnosis. We conducted a cross-sectional study determining 25-hydroxyvitamin D blood levels.

A genome-wide association study identifies SLC8A3 as a susceptibility locus for ACPA-positive rheumatoid arthritis.

Objective: RA patients with serum ACPA have a strong and specific genetic background. The objective of the study was to identify new susceptibility genes for ACPA-positive RA using a genome-wide association approach.

Methods: A total of 924 ACPA-positive RA patients with joint damage in hands and/or feet, and 1524 healthy controls were genotyped in 582 591 single-nucleotide polymorphisms (SNPs) in the discovery phase.

Identification of IRX1 as a Risk Locus for Rheumatoid Factor Positivity in Rheumatoid Arthritis in a Genome-Wide Association Study.

Objective: Rheumatoid factor (RF) is a well-established diagnostic and prognostic biomarker in rheumatoid arthritis (RA). However, ∼20% of RA patients are negative for this anti-IgG antibody. To date, only variation at the HLA-DRB1 gene has been associated with the presence of RF.

Nailfold capillaroscopic findings in primary Sjögren's syndrome with and without Raynaud's phenomenon and/or positive anti-SSA/Ro and anti-SSB/La antibodies.

The aim of this study was to assess nailfold capillaroscopic (NC) findings in patients with primary Sjögren's syndrome (PSS) with and without Raynaud's phenomenon (RP) as well as in the presence of positive anti-SSA/Ro and anti-SSB/La antibodies. Videocapillaroscopy was performed in 150 patients with PSS. Data collected included demographics, presence of RP, PSS symptoms, antinuclear antibodies, rheumatoid factor, anti-Ro, anti-La, anti-CCP, salivary scintigraphy, labial biopsy, and NC findings.

Variation at interleukin-6 receptor gene is associated to joint damage in rheumatoid arthritis.

Introduction: Interleukin-6 (IL-6) cytokine signaling is key in Rheumatoid Arthritis (RA) pathophysiology. Blocking IL-6 receptor (IL6R) has proven to be a highly effective treatment to prevent joint damage. This study was performed to investigate the association between the genetic variation at IL6R gene and the severity of joint damage in RA.

Reference intervals for bone turnover markers in Spanish premenopausal women.

Background: The aims of this study were to establish robust reference intervals and to investigate the factors influencing bone turnover markers (BTMs) in healthy premenopausal Spanish women.

Methods: A total of 184 women (35-45 years) from 13 centers in Catalonia were analyzed. Blood and second void urine samples were collected between 8 a.

A deletion at ADAMTS9-MAGI1 locus is associated with psoriatic arthritis risk.

Objective: Copy number variants (CNVs) have been associated with the risk to develop multiple autoimmune diseases. Our objective was to identify CNVs associated with the risk to develop psoriatic arthritis (PsA) using a genome-wide analysis approach.

Methods: A total of 835 patients with PsA and 1498 healthy controls were genotyped for CNVs using the Illumina HumanHap610 BeadChip genotyping platform.

Variation at FCGR2A and functionally related genes is associated with the response to anti-TNF therapy in rheumatoid arthritis.

Objective: Anti-TNF therapies have been highly efficacious in the management of rheumatoid arthritis (RA), but 25-30% of patients do not show a significant clinical response. There is increasing evidence that genetic variation at the Fc receptor FCGR2A is associated with the response to anti-TNF therapy. We aimed to validate this genetic association in a patient cohort from the Spanish population, and also to identify new genes functionally related to FCGR2A that are also associated with anti-TNF response.

PDE3A-SLCO1C1 locus is associated with response to anti-tumor necrosis factor therapy in psoriatic arthritis.

Aim: Variation at PDE3A-SLCO1C1 locus has been recently associated with the response to anti-TNF therapy in rheumatoid arthritis. We undertook the present study to determine whether PDE3A-SLCO1C1 is also associated with the response to anti-TNF therapy in psoriatic arthritis. Patients & methods: Genomic DNA was obtained from 81 psoriatic arthritis patients that had been treated with anti-TNF therapy.

GWAS replication study confirms the association of PDE3A-SLCO1C1 with anti-TNF therapy response in rheumatoid arthritis.

Aim: The present study was undertaken to replicate the association of candidate genes for anti-TNF response in rheumatoid arthritis. Candidate genes were selected from a recent genome-wide association study on anti-TNF response performed in a population from Denmark.

Materials & Methods: Genomic DNA was obtained from 315 Spanish rheumatoid arthritis patients having received an anti-TNF agent as their first biological therapy.

Risk variants for psoriasis vulgaris in a large case-control collection and association with clinical subphenotypes.

Recent genome-wide association studies (GWASs) have identified >20 new loci associated with the susceptibility to psoriasis vulgaris (PsV) risk. We investigated the association of PsV and its main clinical subphenotypes with 32 loci having previous genome-wide evidence of association with PsV (P < 5e-8) or strong GWAS evidence (P < 5e-5 in discovery and P < 0.05 in replication sample) in a large cohort of PsV patients (n = 2005) and controls (n = 1497).

An eight-gene blood expression profile predicts the response to infliximab in rheumatoid arthritis.

Background: TNF alpha blockade agents like infliximab are actually the treatment of choice for those rheumatoid arthritis (RA) patients who fail standard therapy. However, a considerable percentage of anti-TNF alpha treated patients do not show a significant clinical response. Given that new therapies for treatment of RA have been recently approved, there is a pressing need to find a system that reliably predicts treatment response.

Identification of candidate genes for rituximab response in rheumatoid arthritis patients by microarray expression profiling in blood cells.

Aims: Transient CD20+ B-cell depletion with rituximab is an effective treatment for rheumatoid arthritis (RA). However, there is a subgroup of patients that do not show significant clinical response to rituximab and for these patients, other modes of treatment are preferred. Finding biomarkers for drug response in RA has immense potential for improving treatment and lowering healthcare costs for treating RA patients by facilitating the optimization of their pharmacotherapy.

Genome-wide association study of rheumatoid arthritis in the Spanish population: KLF12 as a risk locus for rheumatoid arthritis susceptibility.

Objective: To identify new genes associated with susceptibility to rheumatoid arthritis (RA), using a 2-stage genome-wide association study.

Methods: Following a liability-based study design, we analyzed 317,503 single-nucleotide polymorphisms (SNPs) in 400 patients with RA and 400 control subjects. We selected a group of candidate SNPs for replication in an independent group of 410 patients with RA and 394 control subjects.