Mary Carns

Molecular signatures in skin associated with clinical improvement during mycophenolate treatment in systemic sclerosis.

Heterogeneity in systemic sclerosis/SSc confounds clinical trials. We previously identified ‘intrinsic’ gene expression subsets by analysis of SSc skin. Here we test the hypotheses that skin gene expression signatures including intrinsic subset are associated with skin score/MRSS improvement during mycophenolate mofetil (MMF) treatment. Gene expression and intrinsic subset assignment were measured in 12 SSc patients’ biopsies and ten controls at baseline, and from serial biopsies of one cyclophosphamide-treated patient, and nine MMF-treated patients. Gene expression changes during treatment were determined using paired t-tests corrected for multiple hypothesis testing. MRSS improved in four of seven MMF-treated patients classified as the inflammatory intrinsic subset. Three patients without MRSS improvement were classified as normal-like or fibroproliferative intrinsic subsets. 321 genes (FDR <5%) were differentially expressed at baseline between patients with and without MRSS improvement during treatment. Expression of 571 genes (FDR <10%) changed between pre- and post-MMF treatment biopsies for patients demonstrating MRSS improvement. Gene expression changes in skin are only seen in patients with MRSS improvement. Baseline gene expression in skin, including intrinsic subset assignment, may identify SSc patients whose MRSS will improve during MMF treatment, suggesting that gene expression in skin may allow targeted treatment in SSc.

Validity of two new patient‐reported outcome measures in systemic sclerosis: Patient‐reported outcomes measurement information system 29‐item health profile and functional assessment of chronic illness therapy–dyspnea short form

Many patient‐reported outcome (PRO) instruments used in systemic sclerosis (SSc) trials are limited by lack of validation, licensing fees, and complicated scoring systems. We assessed the construct validity for discriminative purposes of 2 new PRO instruments, the Patient‐Reported Outcomes Measurement Information System 29‐item Health Profile (PROMIS‐29) and the Functional Assessment of Chronic Illness Therapy–Dyspnea short form (FACIT‐Dyspnea), measuring health status and dyspnea in SSc patients.

Levels of adiponectin, a marker for PPAR-gamma activity, correlate with skin fibrosis in systemic sclerosis: potential utility as biomarker?

IntroductionProgressive fibrosis in systemic sclerosis (SSc) is linked to aberrant transforming growth factor beta (TGF-beta) signaling. Peroxisome proliferator-activated receptor gamma (PPAR-gamma) blocks fibrogenic TGF-beta responses in vitro and in vivo. Reduced expression and function of PPAR-gamma in patients with SSc may contribute to progression of fibrosis. Here we evaluated the levels of adiponectin, a sensitive and specific index of PPAR-gamma activity, as a potential fibrogenic biomarker in SSc.MethodsAdiponectin levels were determined in the sera of 129 patients with SSc and 86 healthy controls, and serial determinations were performed in 27 patients. Levels of adiponectin mRNA in skin biopsies from SSc patients were assessed in an expression profiling microarray dataset. Regulation of adiponectin gene expression in explanted human subcutaneous preadipocytes and fibroblasts was examined by real-time quantitative PCR.ResultsPatients with diffuse cutaneous SSc had reduced serum adiponectin levels. A significant inverse correlation between adiponectin levels and the modified Rodnan skin score was observed. In longitudinal studies changes in serum adiponectin levels were inversely correlated with changes in skin fibrosis. Skin biopsies from a subset of SSc patients showed reduced adiponectin mRNA expression which was inversely correlated with the skin score. An agonist ligand of PPAR-gamma potently induced adiponectin expression in explanted mesenchymal cells in vitro.ConclusionsLevels of adiponectin, reflecting PPAR-gamma activity, are correlated with skin fibrosis and might have potential utility as a biomarker in SSc.

The Pulmonary Fibrosis-Associated MUC5B Promoter Polymorphism Does Not Influence the Development of Interstitial Pneumonia in Systemic Sclerosis

BACKGROUND More than 80% of patients with systemic sclerosis (SSc) develop lung involvement, most commonly interstitial pneumonia (IP). We recently identified a common variant in the promoter region of MUC5B (rs35705950) that has a significant effect on the risk of developing both familial and sporadic forms of IP. We hypothesized that this MUC5B promoter polymorphism is also associated with IP in subjects with SSc. METHODS We examined the minor allele frequency of the MUC5B polymorphism among 231 subjects with SSc, 109 with IP, and 122 without IP. IP diagnosis was confirmed by HRCT imaging and defined as the presence of reticular infiltrates and/or honeycomb cysts. FVC and diffusing capacity of the lung for carbon monoxide (Dlco) were also assessed. RESULTS We found no association between IP and the MUC5B polymorphism among subjects with SSc (OR = 1.1, P = .80). The frequencies of the MUC5B polymorphism among subjects with SSc with IP (10.6%) and without IP (9.4%) were similar to the frequency observed in a population of unaffected control subjects (9.0%). In secondary analyses, we found the MUC5B polymorphism was not significantly associated with either FVC (P = .42) or Dlco (P = .06). No association with SSc-associated IP was found even when we used a more conservative definition of IP (FVC ≤ 70% and evidence of reticulations or honeycombing vs SSc FVC > 70% and no evidence of reticulation or honeycombing). CONCLUSIONS Although SSc-associated IP is clinically, radiologically, and histologically similar to other forms of IP, it appears to have distinct genetic risk factors. This study highlights the genetic and phenotypic heterogeneity of IP in general.

The association between systemic sclerosis disease manifestations and esophageal high-resolution manometry parameters.

We aimed to evaluate the associations between systemic sclerosis (SSc)‐related systemic manifestations and esophageal function using high‐resolution manometry (HRM).

Integrated, multicohort analysis of systemic sclerosis identifies robust transcriptional signature of disease severity

Systemic sclerosis (SSc) is a rare autoimmune disease with the highest case-fatality rate of all connective tissue diseases. Current efforts to determine patient response to a given treatment using the modified Rodnan skin score (mRSS) are complicated by interclinician variability, confounding, and the time required between sequential mRSS measurements to observe meaningful change. There is an unmet critical need for an objective metric of SSc disease severity. Here, we performed an integrated, multicohort analysis of SSc transcriptome data across 7 datasets from 6 centers composed of 515 samples. Using 158 skin samples from SSc patients and healthy controls recruited at 2 centers as a discovery cohort, we identified a 415-gene expression signature specific for SSc, and validated its ability to distinguish SSc patients from healthy controls in an additional 357 skin samples from 5 independent cohorts. Next, we defined the SSc skin severity score (4S). In every SSc cohort of skin biopsy samples analyzed in our study, 4S correlated significantly with mRSS, allowing objective quantification of SSc disease severity. Using transcriptome data from the largest longitudinal trial of SSc patients to date, we showed that 4S allowed us to objectively monitor individual SSc patients over time, as (a) the change in 4S of a patient is significantly correlated with change in the mRSS, and (b) the change in 4S at 12 months of treatment could predict the change in mRSS at 24 months. Our results suggest that 4S could be used to distinguish treatment responders from nonresponders prior to mRSS change. Our results demonstrate the potential clinical utility of a novel robust molecular signature and a computational approach to SSc disease severity quantification.

Longitudinal evaluation of PROMIS-29 and FACIT-Dyspnea short forms in systemic sclerosis

Objective. To assess the sensitivity of the Patient-Reported Outcomes Measurement Information System 29-item Health Profile (PROMIS-29) and the Functional Assessment of Chronic Illness Therapy-Dyspnea 10-item short form (FACIT-Dyspnea) for measuring change in health status and dyspnea in systemic sclerosis (SSc). Methods. One hundred patients with SSc completed the PROMIS-29, FACIT-Dyspnea, and traditional instruments [Medical Research Council Dyspnea Score, St. George’s Respiratory Questionnaire (SGRQ), Health Assessment Questionnaire-Disability Index (HAQ-DI), and Medical Outcomes Study Short Form-36 (SF-36)] at baseline and 1-year visits. PROMIS-29, FACIT-Dyspnea, and traditional instrument change scores were compared across composite modified Medsger Disease Severity and modified Rodnan Skin score (mRSS) change groups. Results. Moderately high Spearman correlation coefficients were observed between FACIT-Dyspnea and SGRQ (r = 0.57), FACIT-Dyspnea functional limitations and SF-36 physical component summary (PCS; r = 0.51), PROMIS-29 physical functioning and HAQ-DI (r = 0.50), and SF-36 PCS (r = 0.52) change scores. In most validity comparisons, PROMIS-29, FACIT-Dyspnea, HAQ-DI, and SF-36 scores performed similarly. While PROMIS-29 covers more content areas than SF-36 (e.g., sleep), it may do so at the expense of responsiveness of its 4-item physical function scale as compared to the multiitem-derived SF-36 PCS. Statistically significant increases in SF-36 role physical (p = 0.01) and physical component scale (p = 0.016), but not PROMIS-29, were observed in patients with mRSS improvement. Conclusion. PROMIS-29 and FACIT-Dyspnea are valid instruments to measure health status and dyspnea in patients with SSc. In physical function assessment, longer PROMIS short forms or computer adaptive testing should be considered to improve responsiveness to the effect of skin disease changes on physical function in patients with SSc.

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

IntroductionThe 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.MethodsTag 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.ResultsIn 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).ConclusionsA PPARG variant is associated with susceptibility to SSc, consistent with a role of PPAR-γ in the pathogenesis of SSc.

Serum amyloid A is a marker for pulmonary involvement in systemic sclerosis.

Inflammation in systemic sclerosis (SSc) is a prominent, but incompletely characterized feature in early stages of the disease. The goal of these studies was to determine the circulating levels, clinical correlates and biological effects of the acute phase protein serum amyloid A (SAA), a marker of inflammation, in patients with SSc. Circulating levels of SAA were determined by multiplex assays in serum from 129 SSc patients and 98 healthy controls. Correlations between SAA levels and clinical and laboratory features of disease were analyzed. The effects of SAA on human pulmonary fibroblasts were studied ex vivo. Elevated levels of SAA were found in 25% of SSc patients, with the highest levels in those with early-stage disease and diffuse cutaneous involvement. Significant negative correlations of SAA were found with forced vital capacity and diffusion capacity for carbon monoxide. Patients with elevated SAA had greater dyspnea and more frequent interstitial lung disease, and had worse scores on patient-reported outcome measures. Incubation with recombinant SAA induced dose-dependent stimulation of IL-6 and IL-8 in normal lung fibroblasts in culture. Serum levels of the inflammatory marker SAA are elevated in patients with early diffuse cutaneous SSc, and correlate with pulmonary involvement. In lung fibroblasts, SAA acts as a direct stimulus for increased cytokine production. These findings suggest that systemic inflammation in SSc may be linked to lung involvement and SAA could serve as a potential biomarker for this complication.

Inhibition of β-Catenin Signaling in the Skin Rescues Cutaneous Adipogenesis in Systemic Sclerosis: A Randomized, Double-Blind, Placebo-Controlled Trial of C-82

Several studies have suggested that Wnts might contribute to skin fibrosis in systemic sclerosis (SSc) by affecting the differentiation of pluripotent dermal cells. We tested C-82, a therapeutic that inhibits canonical Wnt signaling by blocking the interaction of the protein CBP with β-Catenin and inhibiting Wnt-activated genes. We used a trial design formulating C-82 for topical application and conducting a placebo-controlled, double-blinded clinical trial in which patients with diffuse cutaneous SSc were treated with C-82 or placebo on opposite forearms. C-82- compared with placebo-treated forearms did not show any clinical effect. Skin biopsies performed before and after treatment showed a very weak trend toward improvement in the C-82-treated skin of biomarkers of local skin disease, THBS1 and COMP. However, on microarray analysis C-82 treatment strongly up-regulated two clusters of genes that correlate negatively with the severity of SSc skin disease. These clusters are highly associated with metabolism and one gene, PLIN2, expressed only by sebocytes and subcutaneous fat cells. These changes in gene expression strongly support a role for Wnts in differentiation of pluripotent cells into profibrotic fibroblasts and the potential for C-82 with longer treatment to promote fat regeneration in SSc skin.