High Baseline Serum Clara Cell 16 kDa Predicts Subsequent Lung Disease Worsening in Systemic Sclerosis.

OBJECTIVE: Clara cell secretory protein (CC16) is a sensitive marker of bronchial epithelial cell damage. The CC16 serum level is elevated in patients with pulmonary fibrosis, but its predictive value on lung disease progression has not yet been studied. We aimed to assess the value of serum CC16 concentration in predicting lung disease deterioration in patients with systemic sclerosis (SSc). METHODS: We prospectively analyzed and followed 106 patients with SSc during a 4-year period for the risk of developing combined deleterious event, defined as a 10% decrease in total lung capacity or forced vital capacity from baseline, or death, according to serum CC16 at inclusion. Receiver-operating characteristic (ROC) curve analysis was performed for prediction of events during the first 2 years after inclusion. Cumulative risks of combined events were computed by Kaplan-Meier analysis. RESULTS: The best cutoff level of serum CC16 for prediction of a combined event was 33 ng/ml, with 76% sensitivity and 65% specificity (area under the ROC curve: 0.71, 95% CI 0.61-0.81, p < 0.0001). Progression of lung disease evaluated by a mean time-to-event differed between patients with high baseline serum CC16 (42.8 mos, 36.3-49.3) and those with low serum CC16 (56.3 mos, 50.9-61.7; log-rank test, p < 0.001). After adjustment for age, duration of disease, clinical and lung function measures, the risk of combined event occurrence in patients with high serum CC16 was significantly higher than in those with low CC16 (HR 2.9, 1.2-6.75, p < 0.05). CONCLUSION: High baseline serum CC16 predicts lung disease worsening in patients with SSc.

Combined measurement of carbon monoxide and nitric oxide lung transfer does not improve the identification of pulmonary hypertension in systemic sclerosis.

Screening is important to determine whether patients with systemic sclerosis (SSc) have pulmonary hypertension because earlier pulmonary hypertension treatment can improve survival in these patients. Although decreased transfer factor of the lung for carbon monoxide (TLCO) is currently considered the best pulmonary function test for screening for pulmonary hypertension in SSc, small series have suggested that partitioning TLCO into membrane conductance (diffusing capacity) for carbon monoxide (DMCO) and alveolar capillary blood volume (VC) through combined measurement of TLCO and transfer factor of the lung for nitric oxide (TLNO) is more effective to identify pulmonary hypertension in SSc patients compared with TLCO alone. Here, the objective was to determine whether combined TLCO-TLNO partitioned with recently refined equations could more accurately detect pulmonary hypertension than TLCO alone in SSc.For that purpose, 572 unselected consecutive SSc patients were retrospectively recruited in seven French centres.Pulmonary hypertension was diagnosed with right heart catheterisation in 58 patients. TLCO, TLNO and VC were all lower in SSc patients with pulmonary hypertension than in SSc patients without pulmonary hypertension. The area under the receiver operating characteristic curve for the presence of pulmonary hypertension was equivalent for TLCO (0.82, 95% CI 0.79-0.85) and TLNO (0.80, 95% CI 0.76-0.83), but lower for VC (0.75, 95% CI 0.71-0.78) and DMCO (0.66, 95% CI 0.62-0.70).Compared with TLCO alone, combined TLCO-TLNO does not add capability to detect pulmonary hypertension in unselected SSc patients.

Anti-Ephrin Type-B Receptor 2 (EphB2) and Anti-Three Prime Histone mRNA EXonuclease 1 (THEX1) Autoantibodies in Scleroderma and Lupus.

In a pilot ProtoArray analysis, we identified 6 proteins out of 9483 recognized by autoantibodies (AAb) from patients with systemic sclerosis (SSc). We further investigated the 6 candidates by ELISA on hundreds of controls and patients, including patients with Systemic Lupus Erythematosus (SLE), known for high sera reactivity and overlapping AAb with SSc. Only 2 of the 6 candidates, Ephrin type-B receptor 2 (EphB2) and Three prime Histone mRNA EXonuclease 1 (THEX1), remained significantly recognized by sera samples from SSc compared to controls (healthy or with rheumatic diseases) with, respectively, 34% versus 14% (P = 2.10-4) and 60% versus 28% (P = 3.10-8). Above all, EphB2 and THEX1 revealed to be mainly recognized by SLE sera samples with respectively 56%, (P = 2.10-10) and 82% (P = 5.10-13). As anti-EphB2 and anti-THEX1 AAb were found in both diseases, an epitope mapping was realized on each protein to refine SSc and SLE diagnosis. A 15-mer peptide from EphB2 allowed to identify 35% of SLE sera samples (N = 48) versus only 5% of any other sera samples (N = 157), including SSc sera samples. AAb titers were significantly higher in SLE sera (P<0.0001) and correlated with disease activity (p<0.02). We could not find an epitope on EphB2 protein for SSc neither on THEX1 for SSc or SLE. We showed that patients with SSc or SLE have AAb against EphB2, a protein involved in angiogenesis, and THEX1, a 3'-5' exoribonuclease involved in histone mRNA degradation. We have further identified a peptide from EphB2 as a specific and sensitive tool for SLE diagnosis.

RhoA/Rho-kinase activation promotes lung fibrosis in an animal model of systemic sclerosis.

BACKGROUND: Systemic sclerosis (SSc) is a connective-tissue disease characterized by vascular injury, immune-system disorders, and excessive fibrosis of the skin and multiple internal organs. Recent reports found that RhoA/Rho-kinase (ROCK) pathway is implicated in various fibrogenic diseases. Intradermal injection of hypochlorous acid (HOCl)-generating solution induced inflammation, autoimmune activation, and fibrosis, mimicking the cutaneous diffuse form of SSc in humans. Our study aimed firstly to describe pulmonary inflammation and fibrosis induced by HOCl in mice, and secondly to determine whether fasudil, a selective inhibitor of ROCK, could prevent lung and skin fibroses in HOCl-injected mice. METHODS: Female C57BL/6 mice received daily intradermal injection of hypochlorous acid (HOCl) for 6 weeks to induce SSc, with and without daily treatment with fasudil (30 mg·kg(-1)·day(-1)) by oral gavage. RESULTS: HOCl intoxication induced significant lung inflammation (macrophages and neutrophils infiltration), and fibrosis. These modifications were prevented by fasudil treatment. Simultaneously, HOCl enhanced ROCK activity in lung and skin tissues. Inhibition of ROCK reduced skin fibrosis, expression of α-smooth-muscle actin and 3-nitrotyrosine, as well as the activity of ROCK in the fibrotic skin of HOCl-treated mice, through inhibition of phosphorylation of Smad2/3 and ERK1/2. Fasudil significantly decreased the serum levels of anti-DNA-topoisomerase-1 antibodies in mice with HOCl-induced SSc. CONCLUSIONS: Our findings confirm HOCl-induced pulmonary inflammation and fibrosis in mice, and provide further evidence for a key role of RhoA/ROCK pathway in several pathological processes of experimental SSc. Fasudil could be a promising therapeutic approach for the treatment of SSc.

Increased exhaled nitric oxide precedes lung fibrosis in two murine models of systemic sclerosis.

Exhaled nitric oxide (NO) is increased as a result of lung inflammation, which in turn causes subsequent interstitial lung disease in patients with systemic sclerosis (SSc). However, the exact time course of inflammatory and fibrotic changes in the SSc lung has not yet been described. Our objective was to assess the chronological evolution of lung inflammatory and fibrotic processes in mice pre-treated with hypochlorous acid (HOCl) or bleomycin. C57BL/6 mice were randomized into three groups receiving subcutaneous injections of HOCl, bleomycin, or PBS for 2, 4 or 6 weeks. Exhaled NO (eNO) was measured at the end of each injection period and after 2 resting weeks without injection (8 week group). Mice were then sacrificed to obtain skin and lung tissues to measure fibrotic changes and NO synthases (NOS) expression. Increased eNO, inducible NOS and nitrotyrosine expression in bronchial epithelium, lung neutrophils and macrophages were observed at early phases in both HOCl- and bleomycin-treated mice. Conversely, lung vascular endothelial NOS expression decreased significantly at 6th and 8th weeks. Skin fibrosis was significantly increased from the 4th week and lung fibrosis from 6th week. We conclude that lung inflammation occurs early after injury as reflected by increased exhaled NO and inducible NOS expression, and precedes fibrotic changes in skin and lungs of mice pre-treated with bleomycin and HOCl. Early detection and treatment of pulmonary inflammation might be useful in preventing subsequent occurrence of lung fibrosis in SSc patients.

A candidate gene study reveals association between a variant of the Peroxisome Proliferator-Activated Receptor Gamma (PPAR-γ) gene and systemic sclerosis.

INTRODUCTION: The multifunctional nuclear receptor peroxisome proliferator-activated receptor gamma (PPAR-γ) has potent anti-fibrotic effects, and its expression and activity are impaired in patients with systemic sclerosis (SSc). We investigated PPAR-γ gene (PPARG) single nucleotide polymorphisms (SNPs) associated with SSc. METHODS: Tag SNPs spanning PPARG were genotyped in a European ancestry US discovery cohort comprising 152 SSc patients and 450 controls, with replication of our top signal in a European cohort (1031 SSc patients and 1014 controls from France). Clinical parameters and disease severity were analyzed to evaluate clinical associations with PPARG variants. RESULTS: In the discovery cohort, a single PPARG intronic SNP (rs10865710) was associated with SSc (p=0.010; odds ratio=1.52 per C allele, 95% confidence interval 1.10-2.08). This association was replicated in the French validation cohort (p=0.052; odds ratio=1.16 per C allele, 95% confidence interval 1.00-1.35). Meta-analysis of both cohorts indicated stronger evidence for association (p=0.002; odds ratio=1.22 per C allele, 95% confidence interval 1.07-1.40). The rs10865710 C allele was also associated with pulmonary arterial hypertension in the French SSc cohort (p=0.002; odds ratio=2.33 per C allele, 95% confidence interval 1.34-4.03). CONCLUSIONS: A PPARG variant is associated with susceptibility to SSc, consistent with a role of PPAR-γ in the pathogenesis of SSc.

Exhaled NO predicts cyclophosphamide response in scleroderma-related lung disease.

Cyclophosphamide (CYC) is not always effective in patients with scleroderma-related interstitial lung disease (SSc-ILD), hence the need for biomarkers able to predict beneficial responses to CYC therapy. We therefore assessed whether baseline alveolar concentration of nitric oxide (CANO) could predict the favourable response to CYC therapy in patients with SSc-ILD. Nineteen non-smoker patients with SSc-ILD, were enrolled and treated with 6 courses of CYC (0.75 g/m2/monthly) for lung function decline the year before inclusion, and followed-up for 2 years period. We assessed the proportion of favourable response to CYC, defined as improvement of forced vital capacity (FVC) or total pulmonary capacity (TLC) more than 10% between the inclusion and each following visit, according to the validated cut-off of CANO at 8.5 ppb identifying progressive SSc-ILD subset. At inclusion, 7 patients out of 19 had CANO >8.5 ppb. Clinical parameters were comparable between patients with high (>8.5 ppb) and low level of CANO (≤8.5 ppb). After CYC therapy, and during the follow-up, 9 out of 19 patients had favourable response to CYC therapy, 10 did not meet responder's criteria, from whom 4 patients died from respiratory failure. Six out of 7 patients with CANO >8.5 ppb at inclusion had favourable response to CYC therapy, while only 3 out of 12 patients with CANO ≤8.5 ppb responded favourably to CYC therapy (p=0.001). High level of CANO >8.5 ppb reflecting alveolar inflammation identify SSc patients with a greater chance to benefit from CYC treatment with a significant lung function improvement.

Association study of CRP gene in systemic sclerosis in European Caucasian population.

Opsonization and apoptotic cell elements are critical in systemic lupus erythematosus (SLE) and could act through the activation of the innate immunity. C-reactive protein (CRP) belongs to opsonins, and polymorphisms of CRP gene have been shown to be associated with SLE susceptibility. Accumulating evidences show that SLE and systemic sclerosis (SSc) share some genetic susceptibility factors. To determine whether polymorphisms of CRP confer susceptibility to SSc, four SNPs (rs1130864, rs1205, rs1800947 and rs1341665), chosen using Hapmap linkage disequilibrium data and published data, were genotyped in a cohort of 651 SSc patients (569 with antinuclear antibodies, 258 with anti-centromere and 153 with anti-topoisomerase I) and 442 controls. All individuals were of French Caucasian origin. The four polymorphisms were in Hardy-Weinberg equilibrium in the control population. Allelic and genotypic frequencies for these four polymorphisms were found to be similar in SSc patients and controls. Moreover, subphenotype analyses in particular for subgroups having antinuclear antibodies did not detect any difference between SSc patients and controls. These results obtained through a large cohort of European Caucasian SSc patients do not support the implication of CRP gene in the pathogenesis of SSc.

Successful use of infliximab therapy in sight-threatening corticosteroid-resistant Vogt-Koyanagi-Harada disease.

PURPOSE: To report an experience with infliximab in severe corticosteroid-resistant Vogt-Koyanagi-Harada (VKH) disease. DESIGN: Interventional case series. METHODS: The medical records of 2 adult patients were reviewed. RESULTS: Both patients had a visual acuity reduced to hand motion perception bilaterally after 1 month of high-dose corticosteroid therapy, due to multiple exudative retinal detachment involving the fovea. Visual acuity and OCT findings improved immediately after the first infliximab infusion, retinal detachments fully resolved after 1 month and visual acuity returned to normal within 6 months. Despite a negative pretreatment screening, one patient developed multivisceral tuberculosis, which led to infliximab discontinuation after the 7th infusion and was cured by a 9-month ambulatory antibiotic regimen. The other patient received 11 well-tolerated infliximab infusions. Respectively, 9 and 4 months after infliximab discontinuation both patients had normal vision and OCT findings. CONCLUSION: Infliximab showed tremendous therapeutic efficacy in sight-threatening corticosteroid-resistant VKH disease.

Detection of alveolar fibrocytes in idiopathic pulmonary fibrosis and systemic sclerosis.

BACKGROUND: Fibrocytes are circulating precursors for fibroblasts. Blood fibrocytes are increased in patients with idiopathic pulmonary fibrosis (IPF). The aim of this study was to determine whether alveolar fibrocytes are detected in broncho-alveolar lavage (BAL), to identify their prognostic value, and their potential association with culture of fibroblasts from BAL. METHODS: We quantified fibrocytes in BAL from 26 patients with IPF, 9 patients with Systemic Sclerosis(SSc)-interstitial lung disease (ILD), and 11 controls. BAL cells were cultured to isolate alveolar fibroblasts. RESULTS: Fibrocytes were detected in BAL in 14/26 IPF (54%) and 5/9 SSc patients (55%), and never in controls. Fibrocytes were in median 2.5% [0.4-19.7] and 3.0% [2.7-3.7] of BAL cells in IPF and SSc-ILD patients respectively. In IPF patients, the number of alveolar fibrocytes was correlated with the number of alveolar macrophages and was associated with a less severe disease but not with a better outcome. Fibroblasts were cultured from BAL in 12/26 IPF (46%), 5/9 SSc-ILD (65%) and never in controls. The detection of BAL fibrocytes did not predict a positive culture of fibroblasts. CONCLUSION: Fibrocytes were detected in BAL fluid in about half of the patients with IPF and SSc-ILD. Their number was associated with less severe disease in IPF patients and did not associate with the capacity to grow fibroblasts from BAL fluid.

High alveolar concentration of nitric oxide is associated with alveolitis in scleroderma.

Alveolar concentration of nitric oxide (C(A)NO) is a non invasive prognostic marker of systemic sclerosis (SSc) lung disease. There is, however, as yet no direct evidence showing concomitant increase of C(A)NO and the presence of inflammatory cells in alveoli. We have therefore measured C(A)NO and performed broncho-alveolar lavage (BAL) in SSc patients. Exhaled NO was measured, by the means of two different models, the two-compartment model (2CM) and the trumpet model with axial diffusion (TMAD), in 22 SSc patients and compared with 15 healthy controls. BAL was performed in all SSc patients. Alveolitis was defined as lymphocytes >14%, polymorphonuclears >4%, or eosinophils >3% on cell count in BAL fluid. Comparisons of C(A)NO levels were made between SSc patients with, and without, alveolitis. Levels of C(A)NO were significantly higher in SSc patients as compared with controls (p<0.001). Median C(A)NO was significantly higher in SSc patients with alveolitis as compared with SSc patients without alveolitis (8.4ppb; 1st and 3rd interquartile range: 6.0-10.5 vs 3.3ppb; 2.2-3.5; p=0.004 for 2CM and 5.4ppb; 3.2-9.2 vs 3.2ppb; 1.4-3.3, p=0.02 for TMAD), while bronchial airway output of NO (J'awNO, p=0.19), and fractional exhaled NO (F(E)NO, p=0.12) were comparable. C(A)NO was consistently high in SSc patients with alveolitis irrespective of the methods chosen (TMAD or 2CM). Our findings showed that increased C(A)NO was associated with alveolitis in patients with SSc. We submit that C(A)NO could be used as a reliable non-invasive surrogate biomarker of alveolitis in scleroderma lung disease.

[Inflammatory aortitis in giant cell arteritis]. / Aortite inflammatoire au cours de la maladie de Horton.

A sub-clinical inflammatory aortitis is very frequent in patients with giant cell arteritis, and can be the only localization of the disease. In most patients, this aortitis is asymptomatic and is of no consequence on the patient's survival. The relative risk of developing an aortic dissection or aneurysm is 17.3. Evolution towards an aneurysm or an aortic dissection is unpredictable and rare; and seems independent of the disease activity and the associated vascular risk factors. Isolated aortitis treatment is not consensual, but often similar to the treatment of giant cell arteritis and adapted to clinical and biological markers of disease activity. Screening for sub-clinical aortitis with FDG-PET should not be prescribed in patients with typical presentation of giant cell arteritis. A systematic screening of aortic complications in giant cell arteritis patients could be done with a chest X-ray and an abdominal ultrasound possibly completed with an aortic CT-scan at time of diagnosis, in order to look for aneurysms with possible surgical indication.

TGFß receptor gene variants in systemic sclerosis-related pulmonary arterial hypertension: results from a multicentre EUSTAR study of European Caucasian patients.

INTRODUCTION: Systemic sclerosis (SSc)-related pulmonary arterial hypertension (PAH) has emerged as a major mortality prognostic factor. Mutations of transforming growth factor beta (TGFß) receptor genes strongly contribute to idiopathic and familial PAH. OBJECTIVE: To explore the genetic bases of SSc-PAH, we combined direct sequencing and genotyping of candidate genes encoding TGFß receptor family members. MATERIALS AND METHODS: TGFß receptor genes, BMPR2, ALK1, TGFR2 and ENG, were sequenced in 10 SSc-PAH patients, nine SSc and seven controls. In addition, 22 single-nucleotide polymorphisms (SNP) of these four candidate genes were tested for association in a first set of 824 French Caucasian SSc patients (including 54 SSc-PAH) and 939 controls. The replication set consisted of 1516 European SSc (including 219 SSc-PAH) and 3129 controls from the European League Against Rheumatism Scleroderma Trials and Research group network. RESULTS: No mutation was identified by direct sequencing. However, two repertoried SNP, ENG rs35400405 and ALK1 rs2277382, were found in SSc-PAH patients only. The genotyping of 22 SNP including the latter showed that only rs2277382 was associated with SSc-PAH (p=0.0066, OR 2.13, 95% CI 1.24 to 3.65). Nevertheless, this was not replicated with the following result in combined analysis: p=0.123, OR 0.79, 95% CI 0.59 to 1.07. CONCLUSIONS: This study demonstrates the lack of association between these TGFß receptor gene polymorphisms and SSc-PAH using both sequencing and genotyping methods.

Aldolase predicts subsequent myopathy occurrence in systemic sclerosis.

INTRODUCTION: Myopathy related to systemic sclerosis (Myo-SSc) is a disabling and unpredictable complication of SSc. We assessed the predictive value of serum aldolase, creatine kinase (CK), alanine transaminase (ALT), aspartate transaminase (AST) and C-reactive protein (CRP) to estimate the risk of developing Myo-SSc. METHODS: We enrolled 137 SSc patients without proximal muscle weakness in a prospective monocentric study to follow them longitudinally over a four-year period. The risk of occurrence of Myo-SSc was ascertained according to the European NeuroMuscular Centre criteria and was analyzed according to levels of plasma aldolase, CK, transaminase enzymes and CRP at inclusion. Performance of each parameter to predict Myo-SSc occurrence was assessed and compared with the others. RESULTS: The area under the receiver operating characteristic curves (ROC) of plasma aldolase for Myo-SSc occurrence prediction was 0.80 (95% CI: 0.67 to 0.94, P < 0.001), which was higher than that of plasma CK (0.75, P = 0.01), and that of ALT (0.63, P = 0.04). AST and CRP had no predictive value for Myo-SSc occurrence. The best cut-off of aldolase for prediction of Myo-SSc occurrence within three years after inclusion was 9 U/L and higher than the upper normality limit (7 U/L), unlike that of CK and ALT. Myo-SSc occurred more frequently in patients whose plasma aldolase was higher than 9 U/L. Adjusted Hazard Ratio for patients with aldolase > 9 U/L was 10.3 (95% CI: 2.3 to 45.5), P < 0.001. CONCLUSIONS: Increased plasma aldolase level accurately identified SSc patients with high risk to develop subsequent Myo-SSc. This could help initiate appropriate treatment when the disabling muscle damage is still in a reversible stage.

Comparing HLA shared epitopes in French Caucasian patients with scleroderma.

Although many studies have analyzed HLA allele frequencies in several ethnic groups in patients with scleroderma (SSc), none has been done in French Caucasian patients and none has evaluated which one of the common amino acid sequences, (67)FLEDR(71), shared by HLA-DRB susceptibility alleles, or (71)TRAELDT(77), shared by HLA-DQB1 susceptibility alleles in SSc, was the most important to develop the disease. HLA-DRB and DQB typing was performed for a total of 468 healthy controls and 282 patients with SSc allowing FLEDR and TRAELDT analyses. Results were stratified according to patient's clinical subtypes and autoantibody status. Moreover, standardized HLA-DRß1 and DRß5 reverse transcriptase Taqman PCR assays were developed to quantify ß1 and ß5 mRNA in 20 subjects with HLA-DRB1*15 and/or DRB1*11 haplotypes. FLEDR motif is highly associated with diffuse SSc (χ(2) = 28.4, p<10-6) and with anti-topoisomerase antibody (ATA) production (χ(2) = 43.9, p<10-9) whereas TRAELDT association is weaker in both subgroups (χ(2) = 7.2, p = 0.027 and χ(2) = 14.6, p = 0.0007 respectively). Moreover, FLEDR motif- association among patients with diffuse SSc remains significant only in ATA subgroup. The risk to develop ATA positive SSc is higher with double dose FLEDR than single dose with respectively, adjusted standardised residuals of 5.1 and 2.6. The increase in FLEDR motif is mostly due to the higher frequency of HLA-DRB1*11 and DRB1*15 haplotypes. Furthermore, FLEDR is always carried by the most abundantly expressed ß chain: ß1 in HLA DRB1*11 haplotypes and ß5 in HLA-DRB1*15 haplotypes.In French Caucasian patients with SSc, FLEDR is the main presenting motif influencing ATA production in dcSSc. These results open a new field of potential therapeutic applications to interact with the FLEDR peptide binding groove and prevent ATA production, a hallmark of severity in SSc.

Brief report: candidate gene study in systemic sclerosis identifies a rare and functional variant of the TNFAIP3 locus as a risk factor for polyautoimmunity.

OBJECTIVE: Systemic lupus erythematosus (SLE) and systemic sclerosis (SSc) share some pathophysiologic bases as evidenced by individual and familial polyautoimmunity and common susceptibility genetic factors. With regard to the latter, there has been a recent shift from the "common variant" to the "rare variant" paradigm, since rare variants of TNFAIP3 and TREX1 with large effect sizes have recently been discovered in SLE. The present study was undertaken to investigate whether rare variants of TNFAIP3 and TREX1 are also associated with SSc. METHODS: TREX1 single-nucleotide polymorphisms (SNPs) rs3135946, rs7626978, rs3135943, and rs11797 and TNFAIP3 SNPs rs9494883, rs72063345, rs5029939, rs2230926, rs117480515, and rs7749323 were genotyped in a discovery set (985 SSc patients and 1,011 controls), and replication analysis of the most relevant results was performed in a second set (622 SSc patients and 493 controls). RESULTS: No association between TREX1 variants and SSc was observed. For TNFAIP3, we first demonstrated that a low-frequency variant, rs117480515, tagged the recently identified TT>A SLE dinucleotide. In the discovery sample, we observed that all tested TNFAIP3 variants were in linkage disequilibrium and were associated with SSc and various SSc subsets, including the polyautoimmune phenotype. We subsequently genotyped rs117480515 in the replication sample and found it to be associated solely with the SSc polyautoimmune subset (odds ratio 3.51 [95% confidence interval 2.28-5.41], P = 8.58 × 10(-9) ) in the combined populations. Genotype-messenger RNA (mRNA) expression correlation analysis revealed that the TNFAIP3 rs117480515 risk allele was associated with decreased mRNA expression. CONCLUSION: The present findings establish the TNFAIP3 locus as a susceptibility factor for the subset of SSc with a polyautoimmune phenotype. Our results support the implication of rare/low-frequency functional variants and the critical role of A20 in autoimmunity.

Evidence for caveolin-1 as a new susceptibility gene regulating tissue fibrosis in systemic sclerosis.

OBJECTIVE: Caveolin-1 (CAV1) is an inhibitor of tissue fibrosis and has been implicated in the pathogenesis of systemic sclerosis (SSc). The aim of the study was to analyse the possible association of CAV1 gene single nucleotide polymorphisms (SNP) with SSc. METHODS: A total population of 3974 individuals (1355 SSc patients, 2619 controls) was studied. Genotype data for 23 SNP spanning the CAV1-CAV2 gene locus were obtained from a genome-wide scan conducted in a French population (564 SSc patients, 1776 controls). Three CAV1 SNP (rs926198, rs959173, rs9920) displaying the most significant associations with SSc and/or clinical phenotypes were then genotyped in an Italian population (791 SSc patients, 843 controls). CAV1 protein expression in skin biopsies was investigated by immunohistochemistry and western blotting. RESULTS: In the French population, the CAV1 rs959173 C minor allele showed a significant protective association with susceptibility to SSc (OR 0.71, 95% CI 0.59 to 0.86, p(adjusted)=0.009), and with the subset of patients with limited cutaneous SSc (OR 0.71, 95% CI 0.56 to 0.89, p(adjusted)=0.018). The association was replicated in the Italian population and strengthened in the combined populations through Cochran-Mantel-Haenszel meta-analysis (SSc: pooled OR 0.81, 95% CI 0.71 to 0.92, p=0.0018; limited cutaneous SSc: pooled OR 0.80, 95% CI 0.69 to 0.93, p=0.0053). Genotype/protein expression correlations revealed that the rs959173 C protective allele was associated with increased CAV1 protein expression. CONCLUSIONS: These results add CAV1 to the list of SSc susceptibility genes and provide further evidence for the contribution of this pathway in the fibrotic process that characterises SSc pathogenesis.

Independent replication and meta analysis of association studies establish TNFSF4 as a susceptibility gene preferentially associated with the subset of anticentromere-positive patients with systemic sclerosis.

OBJECTIVE: Independent replication with large cohorts and metaanalysis of genetic associations are necessary to validate genetic susceptibility factors. The known tumor necrosis factor (ligand) superfamily, member 4 gene (TNFSF4) systemic lupus erythematosus (SLE) risk locus has been found to be associated with systemic sclerosis (SSc) in 2 studies, but with discrepancies between them for genotype-phenotype correlation. Our objective was to validate TNFSF4 association with SSc and determine the subset with the higher risk. METHODS: Known SLE and SSc TNFSF4 susceptibility variants (rs2205960, rs1234317, rs12039904, rs10912580, and rs844648) were genotyped in 1031 patients with SSc and 1014 controls of French white ancestry. Genotype-phenotype association analysis and meta analysis of available data were performed, providing a population study of 4989 patients with SSc and 4661 controls, all of European white ancestry. RESULTS: Allelic and genotypic associations were observed for the 5 single-nucleotide polymorphisms (SNP) with the subset of patients with SSc who are positive for anticentromere antibodies (ACA) and only a trend for association with SSc and limited cutaneous SSc. Rs2205960 exhibited the strongest allelic association in ACA+ patients with SSc [p = 0.0015; OR 1.37 (1.12-1.66)], with significant intra-cohort association when compared to patients with SSc positive for ACA. Metaanalysis confirmed overall association with SSc but also raised preferential association with the ACA+ subset and strongest effect with rs2205960 [T allele p = 0.00013; OR 1.33 (1.15-1.54) and TT genotype p = 0.00046; OR 2.02 (1.36-2.98)]. CONCLUSION: We confirm TNFSF4 as an SSc susceptibility gene and rs2205960 as a putative causal variant with preferential association in the ACA+ SSc subphenotype.

Alveolar concentration of nitric oxide predicts pulmonary function deterioration in scleroderma.

BACKGROUND: Respiratory failure is a life-threatening and unpredictable complication of systemic sclerosis (SSc). A study was undertaken to assess the value of alveolar nitric oxide (NO) in predicting the risk of lung function deterioration leading to respiratory failure or death in patients with SSc. METHODS: 105 patients with SSc were enrolled in this prospective cohort and were followed longitudinally over a 3-year period during which the risk of occurrence of deleterious events was analysed according to alveolar concentration (C(A)NO), conducting airway output (J'(aw)NO) and fractional concentration (F(E)NO(0.05)) of exhaled NO measured at inclusion. Comparison was made between each NO parameter to predict the occurrence of deleterious events, defined as a 10% decrease in total lung capacity or forced vital capacity from baseline, or death. RESULTS: The area under the receiver operating characteristic curve of C(A)NO to predict the occurrence of the combined events was 0.84 (95% CI 0.76 to 0.92; p<0.001), which was significantly higher than those of J'(aw)NO and F(E)NO(0.05) (p<0.001). A cut-off of C(A)NO of 5.3 ppb had a sensitivity of 88% and a specificity of 62% for the prediction of the occurrence of combined events during follow-up, and was validated in an independent cohort of patients with SSc. Combined events occurred more frequently in patients whose C(A)NO was >5.3 ppb. The adjusted HR for patients with C(A)NO >5.3 ppb was 6.06 (95% CI 2.36 to 15.53; p<0.001). C(A)NO accurately predicted the occurrence of combined events irrespective of forced vital capacity values or the presence of interstitial lung disease at baseline. CONCLUSIONS: Increased C(A)NO accurately identifies patients with SSc with a high risk of developing lung function deterioration and may help to initiate early appropriate treatment.