Hemodynamic Response to Oral Vasodilator Therapy in Systemic Sclerosis-Related Pulmonary Hypertension.

PURPOSE: Although classified as group 1 pulmonary arterial hypertension (PAH), patients with systemic sclerosis-related pulmonary hypertension (SSc-PH) experience poorer clinical response to PAH therapy and increased mortality compared to those with idiopathic PAH. Due to heterogeneity in phenotypes, identifying patients likely to respond to therapy is challenging. The goal of this study was to determine clinical factors associated with hemodynamic response, defined by a > 20% reduction in pulmonary vascular resistance on repeat right heart catheterization. METHODS: We applied a time-to-event model using a retrospective cohort of 39 patients with precapillary SSc-PH, defined by a mean pulmonary artery pressure of ≥ 25 mmHg and pulmonary arterial wedge pressure (PAWP) ≤ 15 mmHg on right heart catheterization. RESULTS: Patients with PAWP ≤ 8 mmHg were nearly fourfold more likely to achieve a hemodynamic response compared to those with PAWP > 8 mmHg (HR 3.88; 95% CI: 1.20, 12.57); each 1 mmHg increase in PAWP was associated with a decreased hazard for hemodynamic response (HR 0.84; 95% CI: 0.70, 1.00). CONCLUSION: In patients with precapillary SSc-PH, PAWP was associated with time to hemodynamic response, suggesting the importance of subclinical cardiac disease in determining hemodynamic response to oral vasodilator therapy.

A Clinical Decision Tool for Risk Stratifying Patients with Systemic Sclerosis-Related Pulmonary Hypertension.

We devised a scoring system to identify patients with systemic sclerosis (SSc) at risk for pulmonary hypertension (PH) and predict all-cause mortality. Using 7 variables obtained via pulmonary function testing, echocardiography, and computed tomographic chest imaging, we applied the score to a retrospective cohort of 117 patients with SSc. There were 60 (51.3%) who were diagnosed with PH by right heart catheterization. Using a scoring threshold ≥ 0, our decision tool predicted PH with a sensitivity, specificity, and accuracy of 0.87 (95% CI 0.75, 0.94), 0.74 (95% CI 0.60, 0.84), and 0.80 (95% CI 0.72, 0.87), respectively. When adjusted for age at PH diagnosis, sex, and receipt of pulmonary arterial vasodilators, each one-point score increase was associated with an adjusted HR of 1.19 (95% CI 1.05, 1.34) for all-cause mortality. With further validation in external cohorts, our simplified clinical decision tool may better streamline earlier detection of PH in SSc.

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.

FLI1 and ERG protein degradation is regulated via Cathepsin B lysosomal pathway in human dermal microvascular endothelial cells.

OBJECTIVES: Friend leukemia integration 1 and erythroblast transformation-specific, important regulators of endothelial cell homeostasis, are reduced in microvascular endothelial cells in scleroderma patients, and their deficiency has been implicated in disease pathogenesis. The goal of this study was to identify the mechanisms involved in the protein turnover of friend leukemia integration 1 and erythroblast transformation-specific in microvascular endothelial cells. METHODS: The effects of lysosome and proteosome inhibitors on friend leukemia integration 1 and erythroblast transformation-specific levels were assessed by Western blotting and capillary morphogenesis. The effect of scleroderma and control sera on the levels of friend leukemia integration 1 and erythroblast transformation-specific was examined. RESULTS: The reduction in the protein levels of friend leukemia integration 1 and erythroblast transformation-specific in response to interferon α or Poly:(IC) was reversed by blocking either lysosomal (leupeptin and Cathepsin B inhibitor) or proteosomal degradation (MG132). MG132, leupeptin or CTSB-(i) also counteracted the anti-angiogenic effects of Poly:(IC) or interferon α. Scleroderma sera reduced protein levels of friend leukemia integration 1 and erythroblast transformation-specific in comparison to control sera. Treatment with CTSB(i) increased the levels of friend leukemia integration 1 and erythroblast transformation-specific in a majority of serum-treated samples. CONCLUSIONS: Inhibition of cathepsin B was effective in reversing the reduction of friend leukemia integration 1 and erythroblast transformation-specific protein levels after treatment with interferon α or scleroderma sera, suggesting that targeting cathepsin B may have a beneficial effect in SSc vascular disease.

ERG regulates lymphatic vessel specification genes and its deficiency impairs wound healing-associated lymphangiogenesis.

OBJECTIVE: Rarefaction of blood and lymphatic vessels in the skin has been reported in SSc (systemic sclerosis, scleroderma). ERG and FLI1 are important regulators of angiogenesis, but their role in lymphatic vasculature is less known. The goal of this study was to determine the role of ERG and FLI1 in postnatal lymphangiogenesis and SSc lymphatic system defects. METHODS: Immunofluorescence was used to detect ERG and FLI1 in SSc and healthy control (HC) skin biopsies. Transcriptional analysis of ERG or FLI1 silenced human dermal lymphatic endothelial cells (LECs) was performed using microarrays. Effects of ERG/FLI1 deficiency on in vitro tubulogenesis in human dermal LECs was examined using a Matrigel assay. Erg and Fli1 endothelial specific knockouts and Erg lymphatic specific knockouts were generated to examine vessel regeneration in mice. RESULTS: ERG and FLI1 protein levels were reduced in the blood and lymphatic vasculature in SSc skin biopsies. ERG was shown to regulate genes involved in lymphatic vessel specification, including VEGFR3/FLT4, LYVE-1, SOX18, and PROX1, while FLI1 enhanced the function of ERG. ERG/FLT4 pathway regulated in vitro tubulogenesis in human LECs. Deficiency of Erg or Fli1 similarly impaired the function of blood vessels in mice. However, only Erg deficiency affected the regeneration of lymphatic vessels during wound healing. CONCLUSION: ERG and FLI1 are essential regulators of blood and lymphatic vessel regeneration. Deficiency of ERG and FLI1 in SSc endothelial cells, may contribute to impairment of blood and lymphatic vasculature in SSc patients.

Role of Left Ventricular Dysfunction in Systemic Sclerosis-Related Pulmonary Hypertension.

BACKGROUND: In systemic sclerosis (SSc), pulmonary hypertension remains a significant cause of morbidity and mortality. Although conventionally classified as group 1 pulmonary arterial hypertension, systemic sclerosis-related pulmonary hypertension (SSc-PH) is a heterogeneous disease. The contribution of left-sided cardiac disease in SSc-PH remains poorly understood. RESEARCH QUESTION: How often does left ventricular (LV) dysfunction occur in SSc among patients undergoing right heart catheterization and how does coexistent LV dysfunction with SSc-PH affect all-cause mortality in this patient population? STUDY DESIGN AND METHODS: We conducted a retrospective, observational study of 165 patients with SSc who underwent both echocardiography and right heart catheterization. LV dysfunction was identified using LV global longitudinal strain (GLS) on speckle-tracking echocardiography based on a defined threshold of > -18%. SSc-PH was defined by a mean pulmonary artery pressure > 20 mmHg. RESULTS: Among patients with SSc who have undergone right heart catheterization, LV dysfunction occurred in 74.2% with SSc-PH and 51.2% without SSc-PH. The median survival of patients with SSc-PH and LV dysfunction was 67.9 (95% CI, 38.3-102.0) months, with a hazard ratio of 12.64 (95% CI, 1.73-92.60) for all-cause mortality when adjusted for age, sex, SSc disease duration, and FVC compared with patients with SSc without pulmonary hypertension with normal LV function. INTERPRETATION: LV dysfunction is common in SSc-PH. Patients with SSc-PH and LV dysfunction by LV GLS have increased all-cause mortality. This suggests that LV GLS may be helpful in identifying underlying LV dysfunction and in risk assessment of patients with SSc-PH.

Cannabis arteritis presenting with Raynaud's and digital ulcerations: a case-based review of a controversial thromboangiitis obliterans-like condition.

Thromboangiitis obliterans (TAO), or Buerger's disease, is a non-atherosclerotic inflammatory disease of the small and medium-sized arteries, veins, and nerves of the legs and arms, strongly associated with the use of tobacco products in young adults. Cannabis arteritis (CA), an entity with similar clinical and pathological features, has been described in marijuana users as a subtype of TAO. Distinction between TAO and CA is challenging, given that most patients use tobacco and marijuana products concomitantly. Herein, we report the case of a male in his late forties who was referred to rheumatology with a 2-month history of hand swelling and bilateral painful digital ulcers with blue discoloration on his fingers and toes. The patient reported daily use of marijuana in blunt wraps and denied tobacco use. His laboratory work-up was negative for scleroderma and other connective tissue diseases. His angiogram confirmed the diagnosis of thromboangiitis obliterans, which was attributed to cannabis arteritis. The patient was started on aspirin and nifedipine daily and discontinued marijuana use. His symptoms resolved within 6 months and have not recurred for more than a year with continued avoidance of marijuana. Our case is one of the few that features primarily marijuana-driven CA and highlights the importance of not only considering marijuana use but also blunt wrap use in patients presenting with Raynaud's phenomenon and ulcerations as cannabis use rises globally.

A Multimodal Prediction Model for Diagnosing Pulmonary Hypertension in Systemic Sclerosis.

OBJECTIVE: Diagnosis of pulmonary hypertension (PH) in systemic sclerosis (SSc) requires an invasive right heart catheterization (RHC), often based on an elevated estimated pulmonary artery systolic pressure on screening echocardiography. However, because of the poor specificity of echocardiography, a greater number of patients undergo RHC than necessary, exposing patients to potentially avoidable complication risks. The development of improved prediction models for PH in SSc may inform decision-making for RHC in these patients. METHODS: We conducted a retrospective study of 130 patients with SSc; 66 (50.8%) were diagnosed with PH by RHC. We used data from pulmonary function testing, electrocardiography, echocardiography, and computed tomography to identify and compare the performance characteristics of 3 models predicting the presence of PH: 1) random forest, 2) classification and regression tree, and 3) logistic regression. For each model, we generated receiver operating curves and calculated sensitivity and specificity. We internally validated models using a train-test split of the data. RESULTS: The random forest model performed best with an area under the curve of 0.92 (95% confidence interval [95% CI] 0.83-1.00), sensitivity of 0.95 (95% CI 0.75-1.00), and specificity of 0.80 (95% CI 0.56-0.94). The 2 most important variables in our random forest model were pulmonary artery diameter on chest computed tomography and diffusing capacity for carbon monoxide on pulmonary function testing. CONCLUSIONS: In patients with SSc, a random forest model can aid in the detection of PH with high sensitivity and specificity and may allow for better patient selection for RHC, thereby minimizing patient risk.

Clinical characteristics and outcomes in pulmonary manifestations of systemic sclerosis: Contribution from pulmonary hypertension and interstitial lung disease severity.

Patients with systemic sclerosis complicated by both pulmonary hypertension (SSc-PH) and interstitial lung disease (SSc-PH-ILD) have poor prognosis compared to those with SSc-PH or SSc-ILD alone. Little is known of how ILD severity affects outcomes in those with SSc-PH, or how PH severity affects outcomes in those with SSc-ILD. Herein, we aimed to delineate clinical features of patients with SSc-PH and SSc-ILD and determine to what degree PH and ILD severity contribute to mortality in patients with SSc. We conducted parallel retrospective studies in cohorts of patients with SSc-PH and SSc-ILD. We categorized ILD severity by pulmonary function testing and PH severity by cardiopulmonary hemodynamics. Our primary outcome was all-cause mortality from time of PH or ILD diagnosis for the SSc-PH and SSc-ILD cohorts, respectively. We calculated adjusted risks of time to all-cause mortality using Cox proportional hazards models. In patients with SSc-PH, severe ILD (HR: 3.54; 95% CI: 1.05, 11.99) was associated with increased hazards for all-cause mortality. By contrast, mild and moderate ILD were not associated with increased mortality risk. In patients with SSc-ILD, both moderate (HR: 2.65; 95% CI: 1.12, 6.31) and severe PH (HR: 6.60; 95% CI: 2.98, 14.61) were associated with increased hazards for all-cause mortality, while mild PH was not. Through our parallel study design, the risk of all-cause mortality increases as severity of concomitant ILD or PH worsens. Therapies that target slowing disease progression earlier in the disease course may be beneficial.

Prognostic Value of Cardiac Axis Deviation in Systemic Sclerosis-Related Pulmonary Hypertension.

OBJECTIVE: Systemic sclerosis-related pulmonary hypertension (SSc-PH) is a common complication of SSc associated with accelerated mortality. The present study was undertaken to investigate whether cardiac axis deviation indicates abnormalities in cardiac function allowing for prognostication of disease severity and mortality. METHODS: This was a retrospective study in which electrocardiograms (ECGs) were reviewed for cardiac axis deviation and their association with echocardiography and cardiopulmonary hemodynamics on right-sided heart catheterization. The primary outcome observed was all-cause mortality from the time of PH diagnosis. RESULTS: ECG results were reviewed from 169 patients with SSc-PH. Right axis deviation (RAD) and left axis deviation (LAD) occurred in 28.4% and 30.8% of patients with SSc-PH, respectively. Compared to those without RAD, patients with RAD exhibited predominantly right-sided cardiac disease on echocardiography and increased PH severity by cardiopulmonary hemodynamics including a greater mean ± SD pulmonary artery pressure (42.0 ± 12.5 mm Hg versus 29.8 ± 7.0 mm Hg) and mean ± SD pulmonary vascular resistance (645.6 ± 443.2 dynes · seconds/cm5 versus 286.3 ± 167.7 dynes · seconds/cm5 ). LAD was associated with predominantly left-sided cardiac disease on echocardiography but was not associated with PH severity on cardiopulmonary hemodynamics. Both RAD (hazard ratio 10.36 [95% confidence interval 4.90-21.93], P < 0.001) and LAD (hazard ratio 2.94 [95% confidence interval 1.53-5.68], P = 0.001) were associated with an increased hazard for all-cause mortality. CONCLUSION: RAD and LAD reflect structural cardiac abnormalities and are associated with poor prognosis in patients with SSc-PH. These findings support the importance of electrocardiography, an inexpensive, widely available noninvasive test, in risk stratification.

Brief Report: Whole-Exome Sequencing to Identify Rare Variants and Gene Networks That Increase Susceptibility to Scleroderma in African Americans.

OBJECTIVE: Whole-exome sequencing (WES) studies in systemic sclerosis (SSc) patients of European American (EA) ancestry have identified variants in the ATP8B4 gene and enrichment of variants in genes in the extracellular matrix (ECM)-related pathway that increase SSc susceptibility. This study was undertaken to evaluate the association of the ATP8B4 gene and the ECM-related pathway with SSc in a cohort of African American (AA) patients. METHODS: SSc patients of AA ancestry were enrolled from 23 academic centers across the US under the Genome Research in African American Scleroderma Patients consortium. Unrelated AA individuals without serologic evidence of autoimmunity who were enrolled in the Howard University Family Study were used as unaffected controls. Functional variants in genes reported in the 2 WES studies in EA patients with SSc were selected for gene association testing using the optimized sequence kernel association test (SKAT-O) and pathway analysis by Ingenuity Pathway Analysis in 379 patients and 411 controls. RESULTS: Principal components analysis demonstrated that the patients and controls had similar ancestral backgrounds, with roughly equal proportions of mean European admixture. Using SKAT-O, we examined the association of individual genes that were previously reported in EA patients and none remained significant, including ATP8B4 (P = 0.98). However, we confirmed the previously reported association of the ECM-related pathway with enrichment of variants within the COL13A1, COL18A1, COL22A1, COL4A3, COL4A4, COL5A2, PROK1, and SERPINE1 genes (corrected P = 1.95 × 10-4 ). CONCLUSION: In the largest genetic study in AA patients with SSc to date, our findings corroborate the role of functional variants that aggregate in a fibrotic pathway and increase SSc susceptibility.

Clinical and serological features of systemic sclerosis in a multicenter African American cohort: Analysis of the genome research in African American scleroderma patients clinical database.

Racial differences exist in the severity of systemic sclerosis (SSc). To enhance our knowledge about SSc in African Americans, we established a comprehensive clinical database from the largest multicenter cohort of African American SSc patients assembled to date (the Genome Research in African American Scleroderma Patients (GRASP) cohort).African American SSc patients were enrolled retrospectively and prospectively over a 30-year period (1987-2016), from 18 academic centers throughout the United States. The cross-sectional prevalence of sociodemographic, clinical, and serological features was evaluated. Factors associated with clinically significant manifestations of SSc were assessed using multivariate logistic regression analyses.The study population included a total of 1009 African American SSc patients, comprised of 84% women. In total, 945 (94%) patients met the 2013 American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) classification criteria for SSc, with the remaining 64 (6%) meeting the 1980 ACR or CREST (calcinosis, Raynaud's phenomenon, esophageal dysmotility, sclerodactyly, telangiectasia) criteria. While 43% were actively employed, 33% required disability support. The majority (57%) had the more severe diffuse subtype and a young age at symptom onset (39.1 ±â€Š13.7 years), in marked contrast to that reported in cohorts of predominantly European ancestry. Also, 1 in 10 patients had a severe Medsger cardiac score of 4. Pulmonary fibrosis evident on computed tomography (CT) chest was present in 43% of patients and was significantly associated with anti-topoisomerase I positivity. 38% of patients with CT evidence of pulmonary fibrosis had a severe restrictive ventilator defect, forced vital capacity (FVC) ≤50% predicted. A significant association was noted between longer disease duration and higher odds of pulmonary hypertension, telangiectasia, and calcinosis. The prevalence of potentially fatal scleroderma renal crisis was 7%, 3.5 times higher than the 2% prevalence reported in the European League Against Rheumatism Scleroderma Trials and Research (EUSTAR) cohort.Our study emphasizes the unique and severe disease burden of SSc in African Americans compared to those of European ancestry.