Jérôme Avouac

Diagnostic and predictive value of anti-cyclic citrullinated protein antibodies in rheumatoid arthritis: a systematic literature review

Objective: To evaluate the two generations of anti-cyclic citrullinated protein (CCP) antibodies as a diagnostic marker of rheumatoid arthritis (RA) and as a predictor of future development of RA in healthy subjects and in patients with early undifferentiated arthritis. Methods: A systematic analysis of the literature published between 1999 and February 2006 was conducted. Data were collected on the sensitivity and specificity of the two generations of anti-CCP antibodies for diagnosing RA and predicting future development of the disease. Results: Among 107 studies initially identified, 68 had interpretable data and were analysed. Diagnostic properties were assessed in 58 studies: mean (SD) sensitivity was 53 (10)% (range 41–68) and 68 (15)% (range 39–94) for anti-CCP1 and anti-CCP2, respectively; mean (SD) specificity was 96 (3)% (range 90–99) and 95 (5)% (range 81–100) for anti-CCP1 and anti-CCP2, respectively. Predictive properties were assessed in 14 studies; odds ratio (95% confidence interval) of anti-CCP1 and anti-CCP2 for the future development of RA were 20 (14 to 31) and 25 (18 to 35), respectively, among patients with early undifferentiated arthritis and 64.5 (8.5 to 489) and 28 (8 to 95), respectively, among healthy subjects. Conclusion: Sensitivity of the second generation of anti-CCP is close to that of rheumatoid factor, with a higher specificity, for distinguishing RA from other rheumatic diseases. Moreover, anti-CCP antibodies appear to be highly predictive of the future development of RA in both healthy subjects and patients with undifferentiated arthritis.

High N-terminal pro-brain natriuretic peptide levels and low diffusing capacity for carbon monoxide as independent predictors of the occurrence of precapillary pulmonary arterial hypertension in patients with systemic sclerosis.

OBJECTIVE To evaluate predictors of pulmonary arterial hypertension (PAH) in a prospective cohort of patients with systemic sclerosis (SSc). METHODS Routine clinical assessments as well as measurements of the diffusing capacity for carbon monoxide/alveolar volume (DLCO/VA) ratio and N-terminal pro-brain natriuretic peptide (NT-proBNP) level were performed in a prospective cohort of 101 SSc patients who did not have PAH or severe comorbidities. After a planned 36-month followup, we evaluated the predictive value of these parameters for the development of precapillary PAH, as demonstrated by cardiac catheterization, disease progression, and death. Criteria for cardiac catheterization were a systolic pulmonary artery pressure (PAP) of >40 mm Hg on echocardiography, a DLCO value of <50% without pulmonary fibrosis, and unexplained dyspnea. RESULTS Eight patients developed PAH, 29 had disease progression, and 10 died during a median followup of 29 months. Kaplan-Meier analysis identified the following baseline parameters as being predictors of PAH: DLCO/VA ratio <70% or <60% (P<0.01 for each comparison), elevated plasma NT-proBNP level (>97th percentile of normal; P = 0.005), echocardiographically estimated systolic PAP >40 mm Hg (P=0.08), and erythrocyte sedimentation rate >28 mm/hour (P=0.015). In multivariate analyses, an elevated baseline NT-proBNP level (hazard ratio [HR] 9.97 [95% confidence interval (95% CI) 1.69-62.42]) and a DLCO/VA ratio <60% (HR 36.66 [95% CI 3.45-387.6]) were predictors of the occurrence of PAH during followup. An increased NT-proBNP level together with a decreased DLCO/VA ratio of <70% was highly predictive of the occurrence of PAH during followup (HR 47.20 [95% CI 4.90-450.33]). CONCLUSION This prospective study identified a decreased DLCO/VA ratio and an increased NT-proBNP as predictors of PAH in SSc. Use of these markers should result in improved PAH risk stratification and allow earlier initiation of therapy.

Prevalence of Pulmonary Hypertension in Systemic Sclerosis in European Caucasians and Metaanalysis of 5 Studies

Objective. To measure the prevalence of different types of pulmonary hypertension (PH) and to identify patients with systemic sclerosis (SSc) at highest risk in a multicenter European sample, with a metaanalysis of relevant studies. Methods. Consecutive patients with SSc recruited at 11 French and Italian centers underwent detailed evaluations, including Doppler echocardiography, chest computed tomography, pulmonary function tests, and right-heart catheterization (RHC), to detect the presence and causes of PH. A metaanalysis was performed, including data from 4 other studies. Results. Among 206 patients in whom it was suspected, PH was confirmed by RHC in 83 patients (7%). Precapillary PH was found in 64 patients (5%), of whom 42 had pulmonary arterial hypertension (PAH) and 22 had PH secondary to interstitial lung disease (ILD). RHC identified 17 patients (1%) with postcapillary PH secondary to left-heart disease. Patients with DLCO/alveolar volume < 70% were more likely to have precapillary PH (87.5% vs 42%; p < 0.0001). Precapillary and postcapillary PH were associated with advanced age (68 ± 14 vs 59 ± 12 yrs, p < 0.0001, and 74 ± 16 vs 61.5 ± 10 yrs, p < 0.0001, respectively). The metaanalysis of 3818 patients showed a prevalence of precapillary PH of 9% (95% CI 6%–12%) and identified advanced age, longer disease duration, and limited cutaneous disease subset as risk factors for this condition. Conclusion. The prevalence of precapillary PH in our multicenter study of SSc was 5%, and in the metaanalysis 9%. Our observations support use of RHC to confirm the presence of precapillary PH suspected by noninvasive testing. We also identified patients at high risk who should be carefully monitored.

Trends in mortality in patients with systemic sclerosis over 40 years: a systematic review and meta-analysis of cohort studies

OBJECTIVE SSc is known as the most severe connective tissue disorder, and to be associated with a high mortality risk. Some improvements in therapy for SSc have been achieved in recent years and some preliminary data have suggested an improvement in patient survival. Thus, we set out to determine whether mortality rate in SSc patients has decreased over the past 40 years through a meta-analysis of cohort studies. METHODS We performed a systematic review and a meta-analysis of literature in MEDLINE and Embase databases from January 1960 to June 2010. All cohort studies reporting on SSc mortality were analysed. We then calculated pooled standardized mortality ratios (SMRs) of SSc mortality and calculated their changes over time using meta-regression analysis. RESULTS Nine studies were included, corresponding to a total of 2691 SSc patients. The pooled SMR was 3.53 [95% CI 3.03, 4.11, P < 0.0001; I(2 )= 93%, P(het) = 0.001]. Mid-cohort year ranged from 1977 to 1995 (before 1980: two studies; 1980-90: five studies; and after 1990: two studies): adjusted meta-regression analysis did not show significant change in SMR over time (P = 0.523). Among 732 deaths, heart involvement was the most frequent cause of deaths (29%) followed by lung involvement. CONCLUSION Our results confirm that SSc is a devastating condition as reflected by a pooled SMR of 3.5. Additionally, SMR has not significantly changed over the past 40 years. Further studies are needed to assess the effect of the most recent available therapies on mortality in SSc.

Genome-Wide Scan Identifies TNIP1, PSORS1C1, and RHOB as Novel Risk Loci for Systemic Sclerosis

Systemic sclerosis (SSc) is an orphan, complex, inflammatory disease affecting the immune system and connective tissue. SSc stands out as a severely incapacitating and life-threatening inflammatory rheumatic disease, with a largely unknown pathogenesis. We have designed a two-stage genome-wide association study of SSc using case-control samples from France, Italy, Germany, and Northern Europe. The initial genome-wide scan was conducted in a French post quality-control sample of 564 cases and 1,776 controls, using almost 500 K SNPs. Two SNPs from the MHC region, together with the 6 loci outside MHC having at least one SNP with a P<10−5 were selected for follow-up analysis. These markers were genotyped in a post-QC replication sample of 1,682 SSc cases and 3,926 controls. The three top SNPs are in strong linkage disequilibrium and located on 6p21, in the HLA-DQB1 gene: rs9275224, P = 9.18×10−8, OR = 0.69, 95% CI [0.60–0.79]; rs6457617, P = 1.14×10−7 and rs9275245, P = 1.39×10−7. Within the MHC region, the next most associated SNP (rs3130573, P = 1.86×10−5, OR = 1.36 [1.18–1.56]) is located in the PSORS1C1 gene. Outside the MHC region, our GWAS analysis revealed 7 top SNPs (P<10−5) that spanned 6 independent genomic regions. Follow-up of the 17 top SNPs in an independent sample of 1,682 SSc and 3,926 controls showed associations at PSORS1C1 (overall P = 5.70×10−10, OR:1.25), TNIP1 (P = 4.68×10−9, OR:1.31), and RHOB loci (P = 3.17×10−6, OR:1.21). Because of its biological relevance, and previous reports of genetic association at this locus with connective tissue disorders, we investigated TNIP1 expression. A markedly reduced expression of the TNIP1 gene and also its protein product were observed both in lesional skin tissue and in cultured dermal fibroblasts from SSc patients. Furthermore, TNIP1 showed in vitro inhibitory effects on inflammatory cytokine-induced collagen production. The genetic signal of association with TNIP1 variants, together with tissular and cellular investigations, suggests that this pathway has a critical role in regulating autoimmunity and SSc pathogenesis.

Association between the IRF5 rs2004640 functional polymorphism and systemic sclerosis: A new perspective for pulmonary fibrosis

OBJECTIVE There is now growing evidence that connective tissue diseases, including systemic sclerosis (SSc), share a common genetic background. Microarray studies support a pivotal role of type I interferon (IFN) in the pathophysiology of connective tissue diseases. Interferon regulatory factors coordinate the expression of type I IFNs, and the IRF5 gene has been identified as a susceptibility gene of systemic lupus and Sjögrens syndrome. The aim of this study was to determine whether the IRF5 rs2004640 single-nucleotide polymorphism is associated with SSc. METHODS The IRF5 rs2004640 (GT) functional polymorphism was genotyped in 1,641 subjects of French European Caucasian origin: a discovery set comprising 427 patients with SSc and 380 control subjects and a replication set comprising 454 patients with SSc and 380 control subjects. RESULTS In both the discovery set and the replication set, the TT genotype was significantly more common in patients with SSc than in control subjects, with an odds ratio (OR) for the combined populations of 1.58 (95% confidence interval [95% CI] 1.18-2.11 [P for trend 0.002]). Analyses of the whole SSc population showed a significant association between homozygosity for the T allele and the presence of antinuclear antibodies (corrected P [Pcorr]=0.04, OR 1.59, 95% CI 1.16-2.17) and fibrosing alveolitis (Pcorr=0.001, OR 2.07, 95% CI 1.38-3.11). In a multivariate analysis model including the diffuse cutaneous subtype of SSc and positivity for anti-topoisomerase I antibodies, the IRF5 rs2004640 TT genotype remained associated with fibrosing alveolitis (P=0.029, OR 1.92, 95% CI 1.07-3.44). CONCLUSION The IRF5 rs2004640 GT substitution is associated with susceptibility to SSc. These data provide new insight into the pathogenesis of SSc, including clues to the mechanisms leading to fibrosing alveolitis.

Cardiac involvement in systemic sclerosis assessed by tissue-doppler echocardiography during routine care: A controlled study of 100 consecutive patients.

OBJECTIVE To assess the prevalence of primary cardiac complications in a large population of patients with systemic sclerosis (SSc), using recently developed echocardiographic techniques. METHODS We prospectively studied 100 consecutive patients (mean +/- SD age 54 +/- 14 years; 86 women) presenting with SSc without pulmonary arterial hypertension or clinical manifestations of heart failure. All patients underwent standard echocardiography, along with measurements of longitudinal velocities by tissue Doppler imaging (TDI) to assess left ventricular (LV) and right ventricular (RV) contractility and LV diastolic function. Results were compared with those in 26 age- and sex-matched healthy controls. RESULTS Patients with SSc had a wider mean left atrial diameter and impaired relaxation compared with the controls. A trend was observed toward a smaller LV ejection fraction (EF) in the patients (mean +/- SD 64.9 +/- 0.6%) than in the controls (67.2 +/- 0.7%), as well as higher pulmonary artery pressure (mean +/- SD 33.3 +/- 0.6 mm Hg versus 30.8 +/- 1.0 mm Hg). LVEF was <55% in 7 patients versus none of the controls. Peak systolic mitral annular velocity as measured by TDI was <7.5 cm/second in 14 patients versus none of the controls (P = 0.040). Mitral annulus early diastolic velocity was <10 cm/second in 30 patients versus 2 of the controls (P = 0.022). Fifteen patients and none of the controls had reduced peak systolic tricuspid annular velocity (P = 0.039). The TDI results correlated with each other, but not with lung abnormalities or other disease characteristics. CONCLUSION Depression of LV and RV systolic and LV diastolic function is common in patients with SSc and is due to primary myocardial involvement. Considering the major contributions of TDI, the addition of this simple technique to standard measurements may improve the detection of heart involvement in patients with SSc.

Radiological hand involvement in systemic sclerosis

Background: The osteoarticular and soft tissue structures of the hand may be involved in systemic sclerosis (SSc), causing functional disability. Objective: To assess radiological hand features in a cross sectional study of SSc patients and in controls. Methods: Hand radiology was done systematically in patients with SSc seen over a two year period and in unselected controls with rheumatoid arthritis or digital trauma. Two independent investigators blind to the diagnosis carried out the radiological assessment. Results: 120 consecutive SSc patients (median (range) age, 56.5 (20 to 90) years; disease duration, 6 (0 to 42) years) and 42 controls (22 with rheumatoid arthritis and 20 with digital trauma) were studied. Radiological abnormalities in SSc patients included erosion (21%), joint space narrowing (28%), arthritis (defined by concomitant erosion and joint space narrowing) (18%), radiological demineralisation (23%), acro-osteolysis (22%), flexion contracture (27%), and calcinosis (23%). In univariate and multivariate analysis, the resorption of distal phalanges was significantly associated with digital ulcers, extra-articular calcification, and pulmonary arterial hypertension; flexion contracture was associated with the diffuse cutaneous form and high HAQ (Health Assessment Questionnaire) disability score. Calcinosis was most often seen in patients with digital ulcers, but was similarly observed in patients with the diffuse or limited cutaneous subtypes. Conclusions: Flexion contracture was associated with disability and occurred in patients with the diffuse cutaneous subtype of SSc, consistent with the tendency towards fibrosis and functional impairment of this subtype. Calcinosis and acro-osteolysis were both associated with vascular complications, highlighting a potential role of vascular injury in such lesions.

STAT4 is a genetic risk factor for systemic sclerosis having additive effects with IRF5 on disease susceptibility and related pulmonary fibrosis

OBJECTIVE Systemic sclerosis (SSc) belongs to the group of connective tissue disorders (CTDs), among which are several disorders characterized by a type I interferon (IFN) signature. The recent identification of an association between IRF5 and SSc further highlights a key role for IFN. STAT4, which encodes STAT-4, contributes to IFN signaling, and its genetic variants were found to be associated with CTDs. The aim of this study was to determine whether the STAT4 rs7574865 single-nucleotide polymorphism is associated with SSc, and whether it interacts with IRF5. METHODS Both the STAT4 rs7574865 and IRF5 rs2004640 polymorphisms were genotyped in 1,855 individuals of French Caucasian origin comprising a discovery set of 440 patients with SSc and 485 control subjects and a replication set of 445 patients with SSc and an additional 485 control subjects. RESULTS STAT4 rs7574865 was shown to be associated with SSc (P=0.001, odds ratio [OR] 1.29, 95% confidence interval [95% CI] 1.11-1.51). This association was not restricted to a particular phenotype. An additive effect of the STAT4 rs7574865 T allele and the IRF5 rs2004640 T allele was observed, resulting in a multiple increased 1.28-fold risk of SSc. The OR for SSc was 2.72 (95% CI 1.86-3.99) for combinations of genotypes with >or=3 risk alleles. An additive effect was also detected for fibrosing alveolitis: carriage of at least 3 risk alleles appeared to be an independent risk factor (P=2.2x10(-4), OR 1.97, 95% CI 1.28-3.04). CONCLUSION Our results establish STAT4 rs7574865 as a new SSc genetic susceptibility factor. STAT4 and IRF5 act with additive effects in terms of susceptibility to both SSc and SSc-related fibrosing alveolitis.

Outcomes of patients with systemic sclerosis-associated polyarthritis and myopathy treated with tocilizumab or abatacept: a EUSTAR observational study

Objective To evaluate the safety and effectiveness of tocilizumab and abatacept in systemic sclerosis (SSc)-polyarthritis or SSc-myopathy. Methods 20 patients with SSc with refractory polyarthritis and seven with refractory myopathy from the EUSTAR (EULAR Scleroderma Trials and Research) network were included: 15 patients received tocilizumab and 12 patients abatacept. All patients with SSc-myopathy received abatacept. Clinical and biological assessments were made at the start of treatment and at the last infusion. Results After 5 months, tocilizumab induced a significant improvement in the 28-joint count Disease Activity Score and its components, with 10/15 patients achieving a EULAR good response. Treatment was stopped in two patients because of inefficacy. After 11 months’ treatment of patients with abatacept, joint parameters improved significantly, with 6/11 patients fulfilling EULAR good-response criteria. Abatacept did not improve muscle outcome measures in SSc-myopathy. No significant change was seen for skin or lung fibrosis in the different groups. Both treatments were well tolerated. Conclusions In this observational study, tocilizumab and abatacept appeared to be safe and effective on joints, in patients with refractory SSc. No trend for any change of fibrotic lesions was seen but this may relate to the exposure time and inclusion criteria. Larger studies with longer follow-up are warranted to further determine the safety and effectiveness of these drugs in SSc.