A replication study confirms the association of TNFSF4 (OX40L) polymorphisms with systemic sclerosis in a large European cohort

<p><b>Objectives</b> The aim of this study was to confirm the influence of TNFSF4 polymorphisms on systemic sclerosis (SSc) susceptibility and phenotypic features.</p> <p><b>Methods</b> A total of 8 European populations of Caucasian ancestry were included, comprising 3014 patients with SSc and 3125 healthy controls. Four genetic variants of TNFSF4 gene promoter (rs1234314, rs844644, rs844648 and rs12039904) were selected as genetic markers.</p> <p><b>Results</b> A pooled analysis revealed the association of rs1234314 and rs12039904 polymorphisms with SSc (OR 1.15, 95% CI 1.02 to 1.31; OR 1.18, 95% CI 1.08 to 1.29, respectively). Significant association of the four tested variants with patients with limited cutaneous SSc (lcSSc) was revealed (rs1234314 OR 1.22, 95% CI 1.07 to 1.38; rs844644 OR 0.91, 95% CI 0.83 to 0.99; rs844648 OR 1.10, 95% CI 1.01 to 1.20 and rs12039904 OR 1.20, 95% CI 1.09 to 1.33). Association of rs1234314, rs844648 and rs12039904 minor alleles with patients positive for anti-centromere antibodies (ACA) remained significant (OR 1.23, 95% CI 1.10 to 1.37; OR 1.12, 95% CI 1.01 to 1.25; OR 1.22, 95% CI 1.07 to 1.38, respectively). Haplotype analysis confirmed a protective haplotype associated with SSc, lcSSc and ACA positive subgroups (OR 0.88, 95% CI 0.82 to 0.96; OR 0.88, 95% CI 0.80 to 0.96; OR 0.86, 95% CI 0.77 to 0.97, respectively) and revealed a new risk haplotype associated with the same groups of patients (OR 1.14, 95% CI 1.03 to 1.26; OR 1.20, 95% CI 1.08 to 1.35; OR 1.23, 95% CI 1.07 to 1.42, respectively).</p> <p><b>Conclusions</b> The data confirm the influence of TNFSF4 polymorphisms in SSc genetic susceptibility, especially in subsets of patients positive for lcSSc and ACA.</p&gt

Complement component C4 structural variation and quantitative traits contribute to sex-biased vulnerability in systemic sclerosis

Altres ajuts: Fondo Europeo de Desarrollo Regional (FEDER), "A way of making Europe".Copy number (CN) polymorphisms of complement C4 play distinct roles in many conditions, including immune-mediated diseases. We investigated the association of C4 CN with systemic sclerosis (SSc) risk. Imputed total C4, C4A, C4B, and HERV-K CN were analyzed in 26,633 individuals and validated in an independent cohort. Our results showed that higher C4 CN confers protection to SSc, and deviations from CN parity of C4A and C4B augmented risk. The protection contributed per copy of C4A and C4B differed by sex. Stronger protection was afforded by C4A in men and by C4B in women. C4 CN correlated well with its gene expression and serum protein levels, and less C4 was detected for both in SSc patients. Conditioned analysis suggests that C4 genetics strongly contributes to the SSc association within the major histocompatibility complex locus and highlights classical alleles and amino acid variants of HLA-DRB1 and HLA-DPB1 as C4-independent signals

Association of a non-synonymous functional variant of the ITGAM gene with systemic sclerosis.

Systemic sclerosis (SSc) is a chronic fibrotic autoimmune disease of complex aetiology which shares genetic similarities with systemic lupus erythematosus (SLE).1 2 One of the novel risk loci that have been recently associated with SLE is the integrin α M (ITGAM) gene, which encodes the α subunit of the αMβ2-integrin.3 4 The most likely causal polymorphism that best explains this association is a non-synonymous single-nucleotide polymorphism (SNP) at the exon 3, rs1143679, which changes the 77th amino acid residue arginine to histidine (R77H). This functional SNP represents one of the highest associated signals with SLE and is predicted to alter the structure and function of the integrin.4 5 To determine whether ITGAM rs1143679 is also associated with SSc susceptibility and clinical manifestations, we genotyped a total of 3735 SSc patients and 3930 matched healthy individuals from seven independent European cohorts of Caucasian origin (Spain, Germany, The Netherlands, Italy, Norway, Sweden and UK) using a predesigned TaqMan® assay (ID: C___2847895_1_) in an ABI 7900HT (both from Applied Biosystems, Foster City, California, USA). Case …Peer Reviewe

Efficacy and safety of abatacept in interstitial lung disease of rheumatoid arthritis: A systematic literature review

Background: Interstitial lung disease (ILD) is a serious complication that represents the second leading cause of death in patients with rheumatoid arthritis (RA). Treatment of RA-ILD remains controversial. The absence of randomized clinical trials and specific ACR or EULAR therapeutic guidelines makes it difficult to establish solid therapeutic recommendations on this issue. In this scenario, real-world data is especially valuable. Objective: To review the literature evidence on the efficacy and safety of abatacept (ABA) for the treatment of rheumatoid arthritis (RA) with associated interstitial lung disease (ILD), given its clinical relevance and the lack of consensus on its therapeutic management. Methods: PUBMED and EMBASE were searched from the date of approval of ABA to the end of 2020 using a combination of RA, ILD and ABA terms following PRISMA guidelines. Identified studies were evaluated by two independent investigators. Results: Nine original studies (1 case series and 8 observational studies) were selected for inclusion in the systematic review. No randomized trial or meta-analysis were identified. The mean age of patients ranged from 61.2 to 75 years and the mean RA duration varied from 7.4 to 18 years. Subcutaneous ABA (74.5%–91%) predominated in combination with conventional synthetic DMARDs (csDMARDs) (58%–75%), and it was used as first-line biologic agent in 22.8%–64.9% of the patients. The mean course of ILD ranged from 1 to 6.7 years, being usual and nonspecific interstitial pneumonia the most frequent patterns. Improvement or stabilization of ILD imaging (76.6%–92.7%) and FVC or DLCO (>85%) was described after a mean follow-up of 17.4–47.8 months, regardless of the pattern of lung involvement, being more remarkable in patients with shorter evolution of ILD. ABA led to significantly lower ILD worsening rates than TNF inhibitors (TNFi) and was associated with a 90% reduction in the relative risk of deterioration of ILD at 24 months of follow-up compared to TNFi and csDMARDs. Combination with methotrexate may have a corticoid-sparing effect. No unexpected adverse events were identified. Conclusions: Current evidence suggests that ABA may be a plausible alternative to treat RA patients with ILD. It would be highly desirable to develop prospective randomized controlled studies to confirm these findings

Role of MUC1 rs4072037 polymorphism and serum KL-6 levels in patients with antisynthetase syndrome

Mucin 1/Krebs von den Lungen-6 (KL-6) is proposed as a serum biomarker of several interstitial lung diseases (ILDs), including connective tissue disorders associated with ILD. However, it has not been studied in a large cohort of Caucasian antisynthetase syndrome (ASSD) patients. Consequently, we assessed the role of MUC1 rs4072037 and serum KL-6 levels as a potential biomarker of ASSD susceptibility and for the differential diagnosis between patients with ILD associated with ASSD (ASSD-ILD +) and idiopathic pulmonary fibrosis (IPF). 168 ASSD patients (149 ASSD-ILD +), 174 IPF patients and 523 healthy controls were genotyped for MUC1 rs4072037 T > C. Serum KL-6 levels were determined in a subgroup of individuals. A significant increase of MUC1 rs4072037 CC genotype and C allele frequencies was observed in ASSD patients compared to healthy controls. Likewise, MUC1 rs4072037 TC and CC genotypes and C allele frequencies were significantly different between ASSD-ILD+ and IPF patients. Additionally, serum KL-6 levels were significantly higher in ASSD patients compared to healthy controls. Nevertheless, no differences in serum KL-6 levels were found between ASSD-ILD+ and IPF patients. Our results suggest that the presence of MUC1 rs4072037 C allele increases the risk of ASSD and it could be a useful genetic biomarker for the differential diagnosis between ASSD-ILD+ and IPF patients

GWAS for systemic sclerosis identifies multiple risk loci and highlights fibrotic and vasculopathy pathways

Systemic sclerosis (SSc) is an autoimmune disease that shows one of the highest mortality rates among rheumatic diseases. We perform a large genome-wide association study (GWAS), and meta-analysis with previous GWASs, in 26,679 individuals and identify 27 independent genome-wide associated signals, including 13 new risk loci. The novel associations nearly double the number of genome-wide hits reported for SSc thus far. We define 95% credible sets of less than 5 likely causal variants in 12 loci. Additionally, we identify specific SSc subtype-associated signals. Functional analysis of high-priority variants shows the potential function of SSc signals, with the identification of 43 robust target genes through HiChIP. Our results point towards molecular pathways potentially involved in vasculopathy and fibrosis, two main hallmarks in SSc, and highlight the spectrum of critical cell types for the disease. This work supports a better understanding of the genetic basis of SSc and provides directions for future functional experiments