Treatment of Systemic Sclerosis-associated Interstitial Lung Disease: Evidence-based Recommendations. An Official American Thoracic Society Clinical Practice Guideline.

Background: Interstitial lung disease (ILD) is a significant cause of morbidity and mortality in patients with systemic sclerosis (SSc). To date, clinical practice guidelines regarding treatment for patients with SSc-ILD are primarily consensus based. Methods: An international expert guideline committee composed of 24 individuals with expertise in rheumatology, SSc, pulmonology, ILD, or methodology, and with personal experience with SSc-ILD, discussed systematic reviews of the published evidence assessed using the Grading of Recommendations, Assessment, Development, and Evaluation approach. Predetermined conflict-of-interest management strategies were applied, and recommendations were made for or against specific treatment interventions exclusively by the nonconflicted panelists. The confidence in effect estimates, importance of outcomes studied, balance of desirable and undesirable consequences of treatment, cost, feasibility, acceptability of the intervention, and implications for health equity were all considered in making the recommendations. This was in accordance with the American Thoracic Society guideline development process, which is in compliance with the Institute of Medicine standards for trustworthy guidelines. Results: For treatment of patients with SSc-ILD, the committee: 1) recommends the use of mycophenolate; 2) recommends further research into the safety and efficacy of (a) pirfenidone and (b) the combination of pirfenidone plus mycophenolate; and 3) suggests the use of (a) cyclophosphamide, (b) rituximab, (c) tocilizumab, (d) nintedanib, and (e) the combination of nintedanib plus mycophenolate. Conclusions: The recommendations herein provide an evidence-based clinical practice guideline for the treatment of patients with SSc-ILD and are intended to serve as the basis for informed and shared decision making by clinicians and patients.

Cumulative disease damage and anti-PM/Scl antibodies are associated with a heavy burden of calcinosis in systemic sclerosis.

OBJECTIVES: Ectopic calcification (calcinosis) is a common complication of SSc, but a subset of SSc patients has a heavy burden of calcinosis. We examined whether there are unique risk factors for a heavy burden of calcinosis, as compared with a light burden or no calcinosis. METHODS: We reviewed the medical records of all patients in the Johns Hopkins Scleroderma Center Research Registry with calcinosis to quantify calcinosis burden using pre-specified definitions. We performed latent class analysis to identify SSc phenotypic classes. We used multinomial logistic regression to determine whether latent phenotypic classes and autoantibodies were independent risk factors for calcinosis burden. RESULTS: Of all patients, 29.4% (997/3388) had calcinosis, and 13.5% (130/963) of those with calcinosis had a heavy burden. The latent phenotypic class with predominantly diffuse skin disease and higher disease severity (characterized by pulmonary hypertension, interstitial lung disease, cardiomyopathy, severe RP, gastrointestinal involvement, renal crisis, myopathy and/or tendon friction rubs) was associated with an increased risk of both a heavy burden [odds ratio (OR) 6.92, 95% CI 3.66, 13.08; P < 0.001] and a light burden (OR 2.88, 95% CI 2.11, 3.95; P < 0.001) of calcinosis compared with the phenotypic class with predominantly limited skin disease. Autoantibodies to PM/Scl were strongly associated with a heavy burden of calcinosis (OR 17.31, 95% CI 7.72, 38.81; P < 0.001) and to a lesser degree a light burden of calcinosis (OR 3.59, 95% CI 1.84, 7.00; P < 0.001). CONCLUSIONS: Calcinosis burden is associated with cumulative SSc-related tissue damage. Independent of disease severity, autoantibodies to PM/Scl are also associated with a heavy burden of calcinosis.

HLA and autoantibodies define scleroderma subtypes and risk in African and European Americans and suggest a role for molecular mimicry.

Systemic sclerosis (SSc) is a clinically heterogeneous autoimmune disease characterized by mutually exclusive autoantibodies directed against distinct nuclear antigens. We examined HLA associations in SSc and its autoantibody subsets in a large, newly recruited African American (AA) cohort and among European Americans (EA). In the AA population, the African ancestry-predominant HLA-DRB1*08:04 and HLA-DRB1*11:02 alleles were associated with overall SSc risk, and the HLA-DRB1*08:04 allele was strongly associated with the severe antifibrillarin (AFA) antibody subset of SSc (odds ratio = 7.4). These African ancestry-predominant alleles may help explain the increased frequency and severity of SSc among the AA population. In the EA population, the HLA-DPB1*13:01 and HLA-DRB1*07:01 alleles were more strongly associated with antitopoisomerase (ATA) and anticentromere antibody-positive subsets of SSc, respectively, than with overall SSc risk, emphasizing the importance of HLA in defining autoantibody subtypes. The association of the HLA-DPB1*13:01 allele with the ATA+ subset of SSc in both AA and EA patients demonstrated a transancestry effect. A direct correlation between SSc prevalence and HLA-DPB1*13:01 allele frequency in multiple populations was observed (r = 0.98, P = 3 × 10-6). Conditional analysis in the autoantibody subsets of SSc revealed several associated amino acid residues, mostly in the peptide-binding groove of the class II HLA molecules. Using HLA α/ß allelic heterodimers, we bioinformatically predicted immunodominant peptides of topoisomerase 1, fibrillarin, and centromere protein A and discovered that they are homologous to viral protein sequences from the Mimiviridae and Phycodnaviridae families. Taken together, these data suggest a possible link between HLA alleles, autoantibodies, and environmental triggers in the pathogenesis of SSc.

Troponin elevation independently associates with mortality in systemic sclerosis.

OBJECTIVES: Cardiac involvement is common in systemic sclerosis (SSc), and elevated troponin may be the only sign of ongoing myocardial disease. The objective was to determine whether the presence of elevated troponin associates with unique SSc characteristics and poor outcomes. METHODS: This retrospective, cross-sectional study included patients in the Johns Hopkins Scleroderma Center Research Registry with any troponin measurement in the past 10 years. Clinical data were compared between those with elevated versus normal troponin. Survival analyses including Cox proportional hazards and regression analyses were performed. RESULTS: 272 patients with a troponin measurement were identified. 83 (31%) had elevated troponin. Compared to those with a normal troponin level, those with elevated troponin level were more likely to have the diffuse SSc subtype (p=0.005), lower left ventricular ejection fraction (57.7 ± 20% vs. 64.4 ± 17.4%, p=0.007), lower forced vital capacity percent predicted (61.1 ± 18.8% vs. 66.8 ± 20.4%, p=0.03), higher right ventricular systolic pressure (51.4 ± 20.9 vs. 43.4 ± 15.9 mmHg, p=0.001), higher Medsger muscle and heart severity scores (p≤0.001), and higher frequency of mortality (28% vs. 9.5%, p≤0.0001). Patients with elevated troponin also have a 2.16-fold (95% CI 1.01-4.63, p=0.046) increased risk of death compared to those without elevated troponin even after adjusting for age, sex, disease duration, and cardiopulmonary risk factors. CONCLUSIONS: Troponin may be a useful prognostic biomarker that may identify a subset of patients with heart disease that may warrant closer clinical investigation.

Linaclotide for the treatment of refractory lower bowel manifestations of systemic sclerosis.

BACKGROUND: Lower gastrointestinal (GI) tract involvement can affect up to 50% of systemic sclerosis (SSc) patients, and may result in malabsorption, pseudo-obstruction, hospitalization, and death. We report our experience with linaclotide, a selective agonist of guanylate cyclase C (GC-C), for SSc patients with refractory lower GI disease. METHODS: We performed an analysis of patients seen at the Johns Hopkins Scleroderma Center and identified patients prescribed linaclotide for refractory lower GI manifestations. Patients had clinical data collected in our longitudinal database. Linaclotide responders were on medication for at least 12 months with documented effectiveness by the treating physician. RESULTS: Thirty-one patients with SSc were treated with linaclotide. At the time of linaclotide initiation, 23 of these patients (74%) were classified as having severe GI disease, as defined by recurrent pseudo-obstruction, malabsorption, and/or need for artificial nutrition (Medsger GI severity score ≥ 3). The majority of patients (90.3%; 28/31) had a treatment response, while only three patients (9.7%) reported ineffectiveness or intolerable side effects. Low-dose linaclotide (≤ 145 mcg daily) was used in 18 patients and was effective in 94%. High-dose therapy (> 145 mcg daily) was effective in 11 of 13 patients (85%). Common side effects were diarrhea, cramping, or bloating (11/31, 35%). Ineffectiveness, cost, and abdominal pain were complaints cited among those who discontinued therapy. CONCLUSION: Linaclotide is a well-tolerated and efficacious pro-secretory and pro-motility agent that can be used to manage refractory lower GI manifestations in SSc. We found that low-dose linaclotide is an effective option and may be better tolerated, though a subset of patients may require high dose regimens.

Longitudinal assessment of interstitial lung disease in single lung transplant recipients with scleroderma.

OBJECTIVE: To investigate the natural history of fibrotic lung disease in recipients of a single lung transplant for scleroderma-associated interstitial lung disease (ILD). METHODS: Global ILD (including ground glass, nodular opacities and fibrosis) was categorized into severity quintiles on first and last post-transplant CT scans, and percent fibrosis by manual contouring was also determined, in nine single lung transplant recipients. Quantitative mean lung densities and volumes for the native and allograft lungs were also acquired. RESULTS: In the native lung, global ILD severity quintile worsened in two cases and percent fibrosis worsened in four cases (range 5-28%). In the lung allograft, one case each developed mild, moderate and severe ILD; of these, new fibrotic ILD (involving <10% of lung) occurred in two cases and acute cellular rejection occurred in one. The average change in native lung density over time was +2.2 Hounsfield Units per year and lung volume +1.4 ml per year, whereas the allograft lung density changed by -5.5 Hounsfield Units per year and total volume +27 ml per year (P = 0.011 and P = 0.039 for native vs allograft density and volume comparisons, respectively). CONCLUSIONS: While the course of ILD in the native and transplanted lungs varied in this series, these cases illustrate that disease progression is common in the native lung, suggesting that either the immune process continues to target autoantigens or ongoing fibrotic pathways are active in the native lung. Mild lung disease may occur in the allograft after several years due to either allograft rejection or recurrent mild ILD.

Right Ventricular Myofilament Functional Differences in Humans With Systemic Sclerosis-Associated Versus Idiopathic Pulmonary Arterial Hypertension.

BACKGROUND: Patients with systemic sclerosis (SSc)-associated pulmonary arterial hypertension (PAH) have a far worse prognosis than those with idiopathic PAH (IPAH). In the intact heart, SSc-PAH exhibits depressed rest and reserve right ventricular (RV) contractility compared with IPAH. We tested whether this disparity involves underlying differences in myofilament function. METHODS: Cardiac myocytes were isolated from RV septal endomyocardial biopsies from patients with SSc-PAH, IPAH, or SSc with exertional dyspnea but no resting PAH (SSc-d); control RV septal tissue was obtained from nondiseased donor hearts (6-7 per group). Isolated myocyte passive length-tension and developed tension-calcium relationships were determined and correlated with in vivo RV function and reserve. RV septal fibrosis was also examined. RESULTS: Myocyte passive stiffness from length-tension relations was similarly increased in IPAH and SSc-PAH compared with control, although SSc-PAH biopsies had more interstitial fibrosis. More striking disparities were found between active force-calcium relations. Compared with controls, maximal calcium-activated force (Fmax) was 28% higher in IPAH but 37% lower in SSc-PAH. Fmax in SSc-d was intermediate between control and SSc-PAH. The calcium concentration required for half-maximal force (EC50) was similar between control, IPAH, and SSc-d but lower in SSc-PAH. This disparity disappeared in myocytes incubated with the active catalytic subunit of protein kinase A. Myocyte Fmax directly correlated with in vivo RV contractility assessed by end-systolic elastance (R2 =0.46, P=0.002) and change in end-systolic elastance with exercise (R2 =0.49, P=0.008) and was inversely related with exercise-induced chamber dilation (R2 =0.63, P<0.002), which also was a marker of depressed contractile reserve. CONCLUSIONS: A primary defect in human SSc-PAH resides in depressed sarcomere function, whereas this is enhanced in IPAH. These disparities correlate with in vivo RV contractility and contractile reserve and are consistent with worse clinical outcomes in SSc-PAH. The existence of sarcomere disease before the development of resting PAH in patients with SSc-d suggests that earlier identification and intervention may prove useful.

Integrin-modulating therapy prevents fibrosis and autoimmunity in mouse models of scleroderma.

In systemic sclerosis (SSc), a common and aetiologically mysterious form of scleroderma (defined as pathological fibrosis of the skin), previously healthy adults acquire fibrosis of the skin and viscera in association with autoantibodies. Familial recurrence is extremely rare and causal genes have not been identified. Although the onset of fibrosis in SSc typically correlates with the production of autoantibodies, whether they contribute to disease pathogenesis or simply serve as a marker of disease remains controversial and the mechanism for their induction is largely unknown. The study of SSc is hindered by a lack of animal models that recapitulate the aetiology of this complex disease. To gain a foothold in the pathogenesis of pathological skin fibrosis, we studied stiff skin syndrome (SSS), a rare but tractable Mendelian disorder leading to childhood onset of diffuse skin fibrosis with autosomal dominant inheritance and complete penetrance. We showed previously that SSS is caused by heterozygous missense mutations in the gene (FBN1) encoding fibrillin-1, the main constituent of extracellular microfibrils. SSS mutations all localize to the only domain in fibrillin-1 that harbours an Arg-Gly-Asp (RGD) motif needed to mediate cell-matrix interactions by binding to cell-surface integrins. Here we show that mouse lines harbouring analogous amino acid substitutions in fibrillin-1 recapitulate aggressive skin fibrosis that is prevented by integrin-modulating therapies and reversed by antagonism of the pro-fibrotic cytokine transforming growth factor ß (TGF-ß). Mutant mice show skin infiltration of pro-inflammatory immune cells including plasmacytoid dendritic cells, T helper cells and plasma cells, and also autoantibody production; these findings are normalized by integrin-modulating therapies or TGF-ß antagonism. These results show that alterations in cell-matrix interactions are sufficient to initiate and sustain inflammatory and pro-fibrotic programmes and highlight new therapeutic strategies.

Autoantibodies and scleroderma phenotype define subgroups at high-risk and low-risk for cancer.

OBJECTIVES: Recent studies demonstrate autoantibodies are powerful tools to interrogate molecular events linking cancer and the development of autoimmunity in scleroderma. Investigating cancer risk in these biologically relevant subsets may provide an opportunity to develop personalised cancer screening guidelines. In this study, we examined cancer risk in distinct serologic and phenotypic scleroderma subsets and compared estimates with the general population. METHODS: Patients in the Johns Hopkins Scleroderma Center observational cohort were studied. Overall and site-specific cancer incidence was calculated in distinct autoantibody and scleroderma phenotypic subsets, and compared with the Surveillance, Epidemiology and End Results registry, a representative sample of the US population. RESULTS: 2383 patients with scleroderma contributing 37 686 person-years were studied. 205 patients (8.6%) had a diagnosis of cancer. Within 3 years of scleroderma onset, cancer risk was increased in patients with RNA polymerase III autoantibodies (antipol; standardised incidence ratio (SIR) 2.84, 95% CI 1.89 to 4.10) and those lacking centromere, topoisomerase-1 and pol antibodies (SIR 1.83, 95% CI 1.10 to 2.86). Among antipol-positive patients, cancer-specific risk may vary by scleroderma subtype; those with diffuse scleroderma had an increased breast cancer risk, whereas those with limited scleroderma had high lung cancer risk. In contrast, patients with anticentromere antibodies had a lower risk of cancer during follow-up (SIR 0.59, 95% CI 0.44 to 0.76). CONCLUSIONS: Autoantibody specificity and disease subtype are biologically meaningful filters that may inform cancer risk stratification in patients with scleroderma. Future research testing the value of targeted cancer screening strategies in patients with scleroderma is needed.

ANCA-associated vasculitis in scleroderma: A renal perspective
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AIMS: Overlap syndrome of ANCA-associated vasculitis (AAV) and scleroderma (SSc) is rare with conflicting data on renal outcomes. We describe the clinical characteristics and treatment outcome of ANCA-associated glomerulonephritis (AAG) in SSc patients followed at a single center. MATERIALS AND METHODS: We conducted a retrospective study of 3,570 patients in our SSc database to identify SSc patients who subsequently developed AAV with renal involvement. Patient demographics, serology, renal function, renal histology, and treatment outcomes were assessed. RESULTS: Of the 3,570 patients, we identified 7 patients who developed acute glomerulonephritis, and all were ANCA positive. The mean age at SSc diagnosis was 47 years, 4 patients were female, and 6 had diffuse SSc. Anti-nuclear antibody (ANA) was positive in all. Mean time of onset of AAV from time of diagnosis of SSc was 6 years, and all were myeloperoxidase (MPO) positive. Patients presented with hematuria, proteinuria, with or without rise in serum creatinine, and all patients had biopsy-proven crescentic glomerulonephritis. One patient required dialysis at presentation. Five patients were treated with cyclophosphamide and steroids, and 2 were treated with rituximab and steroids. Of the 7 patients, 4 did not receive maintenance immunosuppression. Three patients died, and 1 of them experienced relapse with fulminant alveolar hemorrhage. CONCLUSION: AAG in SSc is rare, with disease manifestation and course similar to that of AAV. This case series demonstrates that disease remission can be achieved with standard induction therapy. Vasculitis relapse can occur, and similar to idiopathic AAV, maintenance immunosuppression should be initiated to maintain remission.
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Right Ventricular Functional Reserve in Pulmonary Arterial Hypertension.

BACKGROUND: Right ventricular (RV) functional reserve affects functional capacity and prognosis in patients with pulmonary arterial hypertension (PAH). PAH associated with systemic sclerosis (SSc-PAH) has a substantially worse prognosis than idiopathic PAH (IPAH), even though many measures of resting RV function and pulmonary vascular load are similar. We therefore tested the hypothesis that RV functional reserve is depressed in SSc-PAH patients. METHODS AND RESULTS: RV pressure-volume relations were prospectively measured in IPAH (n=9) and SSc-PAH (n=15) patients at rest and during incremental atrial pacing or supine bicycle ergometry. Systolic and lusitropic function increased at faster heart rates in IPAH patients, but were markedly blunted in SSc-PAH. The recirculation fraction, which indexes intracellular calcium recycling, was also depressed in SSc-PAH (0.32±0.05 versus 0.50±0.05; P=0.039). At matched exercise (25 W), SSc-PAH patients did not augment contractility (end-systolic elastance) whereas IPAH did (P<0.001). RV afterload assessed by effective arterial elastance rose similarly in both groups; thus, ventricular-vascular coupling declined in SSc-PAH. Both end-systolic and end-diastolic RV volumes increased in SSc-PAH patients to offset contractile deficits, whereas chamber dilation was absent in IPAH (+37±10% versus +1±8%, P=0.004, and +19±4% versus -1±6%, P<0.001, respectively). Exercise-associated RV dilation also strongly correlated with resting ventricular-vascular coupling in a larger cohort. CONCLUSIONS: RV contractile reserve is depressed in SSc-PAH versus IPAH subjects, associated with reduced calcium recycling. During exercise, this results in ventricular-pulmonary vascular uncoupling and acute RV dilation. RV dilation during exercise can predict adverse ventricular-vascular coupling in PAH patients.

Immunochip analysis identifies multiple susceptibility loci for systemic sclerosis.

In this study, 1,833 systemic sclerosis (SSc) cases and 3,466 controls were genotyped with the Immunochip array. Classical alleles, amino acid residues, and SNPs across the human leukocyte antigen (HLA) region were imputed and tested. These analyses resulted in a model composed of six polymorphic amino acid positions and seven SNPs that explained the observed significant associations in the region. In addition, a replication step comprising 4,017 SSc cases and 5,935 controls was carried out for several selected non-HLA variants, reaching a total of 5,850 cases and 9,401 controls of European ancestry. Following this strategy, we identified and validated three SSc risk loci, including DNASE1L3 at 3p14, the SCHIP1-IL12A locus at 3q25, and ATG5 at 6q21, as well as a suggested association of the TREH-DDX6 locus at 11q23. The associations of several previously reported SSc risk loci were validated and further refined, and the observed peak of association in PXK was related to DNASE1L3. Our study has increased the number of known genetic associations with SSc, provided further insight into the pleiotropic effects of shared autoimmune risk factors, and highlighted the power of dense mapping for detecting previously overlooked susceptibility loci.

Performance of the Patient-Reported Outcomes Measurement Information System-29 in scleroderma: a Scleroderma Patient-centered Intervention Network Cohort Study.

Objective: The Patient-Reported Outcomes Measurement Information System (PROMIS)-29 assesses seven health-related quality of life domains plus pain intensity. The objective was to examine PROMIS-29v2 validity and explore clinical associations in patients with SSc. Methods: English-speaking SSc patients in the Scleroderma Patient-centered Intervention Network Cohort from 26 sites in Canada, the USA and the UK completed the PROMIS-29v2 between July 2014 and November 2015. Enrolling physicians provided medical data. To examine convergent validity, hypotheses on the direction and magnitude of correlations with legacy measures were tested. For clinical associations, t -tests were conducted for dichotomous variables and PROMIS-29v2 domain scores. Effect sizes (ESs) were labelled as small (<0.25), small to moderate (0.25-0.45), moderate (0.46-0.55), moderate to large (0.56-0.75) and large (>0.75). Results: There were 696 patients (87% female), mean ( s . d .) disease duration 11.6 (8.7) years, 57% with limited cutaneous subtype. Validity indices were consistent with seven of nine hypotheses (| r | =0.51-0.87, P < 0.001), with minor divergence for two hypotheses. Gastrointestinal involvement was associated with significantly worse outcomes for all eight PROMIS-29v2 domains (moderate or moderate to large ES in six of eight). Presence of joint contractures was associated with significant decrements in seven domains (small or small to moderate ESs). Skin thickening, diffuse cutaneous subtype and presence of overlap syndromes were significantly associated (small or small to moderate ESs) with five or six domains. Conclusion: This study further establishes the validity of the PROMIS-29v2 in SSc and underlines the importance of gastrointestinal symptoms and joint contractures in reduced health-related quality of life.

Evaluation of cancer-associated myositis and scleroderma autoantibodies in breast cancer patients without rheumatic disease.

OBJECTIVES: Systemic sclerosis (scleroderma) and dermatomyositis are two prototypic autoimmune diseases that are strongly associated with malignancy. While specific autoantibodies in these diseases are markers of an increased risk of cancer at scleroderma and dermatomyositis onset, it is not known whether these autoantibodies are biomarkers of cancer risk in patients without rheumatic disease. METHODS: In a matched case-control study of women without rheumatic disease, identified from a familial breast cancer cohort, 50 breast cancer cases and 50 controls were assayed for 3 autoantibodies that are known markers of cancer-associated scleroderma and dermatomyositis: anti-RNA polymerase III, anti-NXP2, and anti-TIF1γ. RESULTS: No subject had moderate or strong autoantibody positivity. Eleven women were borderline positive for at least one autoantibody. The prevalence of borderline autoantibody positivity did not differ between cases and controls. CONCLUSIONS: Our results suggest that scleroderma and dermatomyositis autoantibodies are cancer biomarkers only in patients with clinical manifestations of specific rheumatic diseases and are unlikely to improve risk stratification for cancer in the general population. However, prospective studies are needed to examine whether scleroderma and dermatomyositis autoantibodies are markers of malignancy in other cancer types.

Prediction and impact of attacks of Raynaud's phenomenon, as judged by patient perception.

OBJECTIVE: To evaluate whether patients can predict attacks of RP (if so, this would have implications for developing new treatments) and to evaluate the impact of RP attacks on quality of life (QoL). METHODS: Individuals with RP were invited through international patient associations to participate in an online survey. RESULTS: Responses from 443 subjects with self-reported RP from 15 countries were evaluable. The mean age of subjects was 41 years (91% female). Fifty-eight per cent of subjects reported they could predict at least 51% of RP attacks, and 57% could predict attack severity either fairly well or better [with 43% predicting severity only poorly (30%) or very poorly (13%)]. Sixty-four per cent of subjects reported a poor or very poor current ability to prevent/control RP attacks. One hundred and eighty-two subjects (41%) reported current or previous use of medications for RP: 82% reported at least one currently used medication being tolerated, but only 16% reported at least one current medication being effective. Most subjects (78%) reported making at least one life adjustment due to RP, with more in subjects with secondary RP compared with primary RP (87% vs 71%, P = 0.001). Current QoL with RP was impaired [mean = 6/10 (10 best imaginable)] and secondary RP subjects reported a greater absolute improvement when asked to imagine their QoL without RP (2.3 vs 3.3 P = 0.0002). CONCLUSION: Subjects' ability to predict RP attacks is limited. Treatments were generally considered tolerable but seldom fully effective. Our results confirm an unmet need for new treatments. RP significantly impacts on QoL in all subjects.

Pilot study to determine whether transient receptor potential melastatin type 8 (TRPM8) antibodies are detected in scleroderma.

OBJECTIVES: A key mediator in cold-sensation is the protein transient receptor potential melastatin 8 (TRPM8), which is expressed on sensory nerves and cutaneous blood vessels. These receptors are activated by cold temperatures and play a key role in body thermoregulation. Cold sensitivity and Raynaud's phenomenon are frequent clinical features in scleroderma, and are thought to be secondary to a local defect in cutaneous thermoregulation. We investigated whether autoantibodies targeting TRPM8 were present in the sera of patients with scleroderma as evidence for a possible mechanism for an acquired immune mediated defect in thermoregulation. METHODS: Sera from 50 well-characterised scleroderma patients with Raynaud's phenomenon were studied. TRPM8 autoantibodies were assayed as follows: 1. immunoprecipitation with 35S-methionine-labelled TRPM8 generated by in vitro transcription and translation, 2. immunoblotting lysates made from cells transiently transfected with TRPM8 cDNA, 3. Immunoprecipitation of TRPM8 transfected lysates with detection by blotting and 4. flow cytometry. RESULTS: Fifty scleroderma patients with Raynaud's phenomenon (41 female, 39 Caucasian, 23 with limited scleroderma, and 20 with history of cancer) were studied. Four different methods to assay for TRPM8 antibodies were set up, optimised and validated using commercial antibodies. All 50 scleroderma patients' sera were assayed using each of the above methods, and all were negative for TRPM8 autoantibodies. CONCLUSIONS: Antibodies against TRPM8 are not found in scleroderma patient sera, suggesting that the abnormal cold sensitivity and associated abnormal vascular reactivity in scleroderma patients is not the result of an immune process targeting TRPM8.

Myopathy in scleroderma, its identification, prevalence, and treatment: lessons learned from cohort studies.

PURPOSE OF REVIEW: This review discusses the characterization of myopathy in scleroderma with a focus on new developments in imaging, biomarkers, and therapy, and details several current reports and several seminal reports prior to 2012. RECENT FINDINGS: In the past year, studies have shown that MRI techniques highlight the importance of muscle edema in scleroderma, and that aldolase may be a useful biomarker to predict incident myopathy. When compared to studies preceding 2012, both the current and prior reports too often fail to account for the full spectrum of muscle disease in scleroderma. There remain no uniform classification criteria that are routinely integrated into clinical research reports. Thus, important questions remain to be answered, including risk factors for developing myopathy, optimal screening and diagnostic strategies, and efficacious therapies. But, just as important is the priority to systematically define what the true entity(ies) of myopathy is in scleroderma. SUMMARY: Scleroderma myopathy is a heterogeneous group of muscle disorders among patients with underlying scleroderma which requires robust studies to clarify the full spectrum of disease.