Systemic sclerosis-associated pulmonary arterial hypertension

Molecular Changes Implicate Angiogenesis and Arterial Remodeling in Systemic Sclerosis-Associated and Idiopathic Pulmonary Hypertension

BACKGROUND

Pulmonary hypertension (PH) is a common complication of systemic sclerosis (SSc) and a leading cause of mortality among patients with this disease. PH can also occur as an idiopathic condition (idiopathic pulmonary arterial hypertension). Investigation of transcriptomic alterations in vascular populations is critical to elucidating cellular mechanisms underlying pathobiology of SSc-associated and idiopathic PH.

METHODS

We analyzed single-cell RNA sequencing profiles of endothelial and perivascular mesenchymal populations from explanted lung tissue of patients with SSc-associated PH (n=16), idiopathic pulmonary arterial hypertension (n=3), and healthy controls (n=15). Findings were validated by immunofluorescence staining of explanted human lung tissue.

RESULTS

Three disease-associated endothelial populations emerged. Two angiogenic endothelial cell (EC) subtypes markedly expanded in SSc-associated PH lungs: tip ECs expressing canonical tip markers PGF and APLN and phalanx ECs expressing genes associated with vascular development, endothelial barrier integrity, and Notch signaling. Gene regulatory network analysis suggested enrichment of Smad1 (SMAD family member 1) and PPAR-γ (peroxisome proliferator-activated receptor-γ) regulon activities in these 2 populations, respectively. Mapping of potential ligand-receptor interactions highlighted Notch, apelin-APJ (apelin receptor), and angiopoietin-Tie (tyrosine kinase with immunoglobulin-like and EGF-like domains 1) signaling pathways between angiogenic ECs and perivascular cells. Transitional cells, expressing both endothelial and pericyte/smooth muscle cell markers, provided evidence for the presence of endothelial-to-mesenchymal transition. Transcriptional programs associated with arterial endothelial dysfunction implicated VEGF-A (vascular endothelial growth factor-A), TGF-β1 (transforming growth factor beta-1), angiotensin, and TNFSF12 (tumor necrosis factor ligand superfamily member 12)/TWEAK (TNF-related weak inducer of apoptosis) in the injury/remodeling phenotype of PH arterial ECs.

CONCLUSIONS

These data provide high-resolution insights into the complexity and plasticity of the pulmonary endothelium in SSc-associated PH and idiopathic pulmonary arterial hypertension and provide direct molecular insights into soluble mediators and transcription factors driving PH vasculopathy.

Pulmonary Hypertension in Connective Tissue Diseases Other than Systemic Sclerosis

Pulmonary hypertension (PH) is a known complication of certain connective tissue diseases (CTDs), with systemic sclerosis (SSc) being the most common in the Western world. However, PH in association with non-SSc CTD such as systemic lupus erythematous, mixed connective tissue disease, and primary Sjögren's syndrome constitutes a distinct subset of patients with inherently different epidemiologic profiles, pathophysiologic mechanisms, clinical features, therapeutic options, and prognostic implications. The purpose of this review is to inform a practical approach for clinicians evaluating patients with non-SSc CTD-associated PH.The development of PH in these patients involves a complex interplay between genetic factors, immune-mediated mechanisms, and endothelial cell dysfunction. Furthermore, the broad spectrum of CTD manifestations can contribute to the development of PH through various pathophysiologic mechanisms, including intrinsic pulmonary arteriolar vasculopathy (pulmonary arterial hypertension, Group 1 PH), left-heart disease (Group 2), chronic lung disease (Group 3), chronic pulmonary artery obstruction (Group 4), and unclear and/or multifactorial mechanisms (Group 5). The importance of diagnosing PH early in symptomatic patients with non-SSc CTD is highlighted, with a review of the relevant biomarkers, imaging, and diagnostic procedures required to establish a diagnosis.Therapeutic strategies for non-SSc PH associated with CTD are explored with an in-depth review of the medical, interventional, and surgical options available to these patients, emphasizing the CTD-specific considerations that guide treatment and aid in prognosis. By identifying gaps in the current literature, we offer insights into future research priorities that may prove valuable for patients with PH associated with non-SSc CTD.

Peripheral microvascular function is linked to cardiac involvement on cardiovascular magnetic resonance in systemic sclerosis-related pulmonary arterial hypertension

AIMS

Systemic sclerosis (SSc) is characterized by vasculopathy, inflammation, and fibrosis, and carries one of the worst prognoses if patients also develop pulmonary arterial hypertension (PAH). Although PAH is a known prognosticator, patients with SSc-PAH demonstrate disproportionately high mortality, presumably due to cardiac involvement. In this cross-sectional study, the relationship between cardiac involvement revealed by cardiovascular magnetic resonance (CMR) and systemic microvascular disease severity measured with nailfold capillaromicroscopy (NCM) in patients with SSc-PAH is evaluated and compared with patients with idiopathic PAH (IPAH).

METHODS AND RESULTS

Patients with SSc-PAH and IPAH underwent CMR, echocardiography, and NCM with post-occlusive reactivity hyperaemia (PORH) testing on the same day. CMR imaging included T2 (oedema), native, and post-contrast T1 mapping to measure the extracellular volume fraction (ECV, fibrosis) and adenosine-stress-perfusion imaging measuring the relative myocardial upslope (microvascular coronary perfusion). Measures of peripheral microvascular function were related to CMR indices of oedema, fibrosis, and myocardial perfusion. SSc-PAH patients (n = 20) had higher T2 values and a trend towards a higher ECV, compared with IPAH patients (n = 5), and a lower nailfold capillary density (NCD) and reduced capillary recruitment after PORH. NCD correlated with ECV and T2 (r = -0.443 and -0.464, respectively, P < 0.05 for both) and with markers of diastolic dysfunction on echocardiography. PORH testing, but not NCD, correlated with the relative myocardial upslope (r = 0.421, P < 0.05).

CONCLUSION

SSc-PAH patients showed higher markers of cardiac fibrosis and inflammation, compared with IPAH patients. These markers correlated well with peripheral microvascular dysfunction, suggesting that SSc-driven inflammation and vasculopathy concurrently affect peripheral microcirculation and the heart. This may contribute to the disproportionate high mortality in SSc-PAH.

Systemic scleroderma: Review and updated approach and case description to addressing pulmonary arterial hypertension and idiopathic pulmonary fibrosis: A dual challenge in treatment

Pulmonary arterial hypertension (PAH), idiopathic pulmonary fibrosis (IPF), and scleroderma (SSc) are three interrelated medical conditions that can result in significant morbidity and mortality. Pulmonary hypertension, a condition marked by high blood pressure in the lungs, can lead to heart failure and other complications. Idiopathic pulmonary fibrosis, a progressive lung disease characterised by scarring of lung tissue, can cause breathing difficulties and impaired oxygenation. Scleroderma, an autoimmune disease, can induce thickening and hardening of the skin and internal organs, including the lungs, leading to pulmonary fibrosis and hypertension. Currently, there is no cure for any of these conditions. However, early detection and proper management can improve the quality of life and prognosis of a patient. This review focusses on PH and IPF in patients with SSc, providing information on the causes, symptoms, and treatment of these conditions, together with illustrative images. It also provides an overview of interrelated medical conditions: PH, IPF, and SSc. It emphasises the importance of early detection and proper management to improve patient quality of life and prognosis.

Vasoactive drugs for the treatment of pulmonary hypertension associated with interstitial lung diseases: a systematic review

OBJECTIVES

Vasoactive drugs have exhibited clinical efficacy in addressing pulmonary arterial hypertension, manifesting a significant reduction in morbidity and mortality. Pulmonary hypertension may complicate advanced interstitial lung disease (PH-ILD) and is associated with high rates of disability, hospitalisation due to cardiac and respiratory illnesses, and mortality. Prior management hinged on treating the underlying lung disease and comorbidities. However, the INCREASE trial of inhaled treprostinil in PH-ILD has demonstrated that PH-ILD can be effectively treated with vasoactive drugs.

METHODS

This comprehensive systematic review examines the evidence for vasoactive drugs in the management of PH-ILD.

RESULTS

A total of 1442 pubblications were screened, 11 RCTs were considered for quantitative synthesis. Unfortunately, the salient studies are limited by population heterogeneity, short-term follow-up and the selection of outcomes with uncertain clinical significance.

CONCLUSIONS

This systematic review underscores the necessity of establishing a precision medicine-oriented strategy, directed at uncovering and addressing the intricate cellular and molecular mechanisms that underlie the pathophysiology of PH-ILD.

PROSPERO REGISTRATION NUMBER

CRD42023457482.

A hypothesis: Potential contributions of metals to the pathogenesis of pulmonary artery hypertension

Pulmonary artery hypertension (PAH) is characterized by vasoconstriction and vascular remodeling resulting in both increased pulmonary vascular resistance (PVR) and pulmonary artery pressure (PAP). The chronic and high-pressure stress experienced by endothelial cells can give rise to inflammation, oxidative stress, and infiltration by immune cells. However, there is no clearly defined mechanism for PAH and available treatment options only provide limited symptomatic relief. Due to the far-reaching effects of metal exposures, the interaction between metals and the pulmonary vasculature is of particular interest. This review will briefly introduce the pathophysiology of PAH and then focus on the potential roles of metals, including essential and non-essential metals in the pathogenic process in the pulmonary arteries and right heart, which may be linked to PAH. Based on available data from human studies of occupational or environmental metal exposure, including lead, antimony, iron, and copper, the hypothesis of metals contributing to the pathogenesis of PAH is proposed as potential risk factors and underlying mechanisms for PAH. We propose that metals may initiate or exacerbate the pathogenesis of PAH, by providing potential mechanism by which metals interact with hypoxia-inducible factor and tumor suppressor p53 to modulate their downstream cellular proliferation pathways. These need further investigation. Additionally, we present future research directions on roles of metals in PAH.

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.

Acute cardiovascular complications of immune-mediated systemic inflammatory diseases

Immune-mediated systemic inflammatory conditions (IMIDs) are associated with an increased risk of atherosclerosis and adverse cardiovascular (CV) events secondary to pathogenic inflammation and derangements in the innate and adaptive immune responses inherent to the underlying rheumatic diseases. As the intersection of cardio-rheumatology continues to expand, a multi-disciplinary approach must be considered to optimize clinical outcomes and long-term survival. This review will highlight acute cardiac manifestations of systemic inflammatory diseases and propose a clinically relevant framework for diagnosis, management, and the role of integrated multimodality imaging.

Clinical features of pulmonary arterial hypertension associated with systemic sclerosis

Systemic sclerosis is an autoimmune disorder of the connective tissue characterized by disordered inflammation and fibrosis leading to skin thickening and visceral organ complications. Pulmonary involvement, in the form of pulmonary arterial hypertension and/or interstitial lung disease, is the leading cause of morbidity and mortality among individuals with scleroderma. There are no disease-specific therapies for pulmonary involvement of scleroderma, and pulmonary arterial hypertension in this cohort has typically been associated with worse outcomes and less clinical response to modern therapy compared to other forms of Group I pulmonary hypertension in the classification from the World Symposium on Pulmonary Hypertension. Ongoing research aims to delineate how pathologic microvascular remodeling and fibrosis contribute to this poor response and offer a window into future therapeutic targets.

Scleroderma pulmonary arterial hypertension: the same as idiopathic pulmonary arterial hypertension?

PURPOSE OF REVIEW

Pulmonary arterial hypertension (PAH) is a common complication of systemic sclerosis (SSc), which confers significant morbidity and mortality. The current therapies and treatment strategies for SSc-associated PAH (SSc-PAH) are informed by those used to treat patients with idiopathic PAH (IPAH). There are, however, important differences between these two diseases that impact diagnosis, treatment, and outcomes.

RECENT FINDINGS

Both SSc-PAH and IPAH are incompletely understood with ongoing research into the underlying cellular biology that characterize and differentiate the two diseases. Additional research seeks to improve identification among SSc patients in order to diagnose patients earlier in the course of their disease. Novel therapies specifically for SSc-PAH such as rituximab and dimethyl fumarate are under investigation.

SUMMARY

Although patients with SSc-PAH and IPAH present with similar symptoms, there are significant differences between these two forms of PAH that warrant further investigation and characterization of optimal detection strategies, treatment algorithms, and outcomes assessment.

Incidence and Predictors of an Abnormal Liver Function Test Among 674 Systemic Sclerosis Patients: A Cohort Study

Background

Abnormal liver function tests (LFTs) can indicate cirrhosis or liver cancer leading to mortality among systemic sclerosis (SSc) patients. No recent studies have investigated the clinical predictors of an abnormal LFT in SSc. We aimed to determine the incidence of abnormal LFT (including from hepatitis and cholestasis) and to identify its clinical predictors in SSc patients.

Methods

An historical cohort was conducted on 674 adult SSc patients who attended the Scleroderma Clinic, Khon Kaen University, between January 2012 and November 2019 and who underwent routine screening for LFT. A Cox regression was used to analyze the clinical predictors of abnormal LFT.

Results

Four hundred and thirty cases, representing 4190 person-years, had abnormal LFTs (viz, from hepatitis, cholestasis, and cholestatic hepatitis) for an incidence rate of 10.2 per 100 person-years. The respective incidence of hepatitis, cholestasis, and cholestatic hepatitis was 20.5, 12.9, and 20.4 per 100 person-years. The respective median first-time detection of hepatitis, cholestasis, and cholestatic hepatitis was 3.0, 5.9, and 2.8 years, and none had signs or symptoms suggestive of liver disease. According to the Cox regression analysis, the predictors of an abnormal LFT in SSc were elderly onset of SSc (hazard ratio (HR) 1.02), alcoholic drinking (HR 1.74), high modified Rodnan Skin Score (mRSS) (HR 1.03), edematous skin (HR 2.94), Raynaud's phenomenon (HR 1.39), hyperCKaemia (HR 1.88), and methotrexate use (HR 1.55). In contrast, current sildenafil treatment (HR 0.63) and high serum albumin (HR 0.70) were protective factors.

Conclusion

Occult hepatitis, cholestasis, and cholestatic hepatitis can be detected in SSc patients using LFT screening, especially in cases of early disease onset. The long-term outcome is uncertain, and more longitudinal research is required.

Combination of echocardiography and pulmonary function tests could predict no complication of pulmonary hypertension during 5 years in patients with systemic sclerosis

OBJECTIVE

To determine whether complications of pulmonary hypertension (PH) can be predicted by noninvasive screening tests in systemic sclerosis (SSc).

METHODS

Forty-seven of 113 SSc patients underwent right heart catheterization (RHC) during 2011-2014. Clinical data, hemodynamic features, echocardiography, and pulmonary function tests had been followed up from the first RHC until 5 years later.

RESULTS

At the first RHC, out of 44 patients, 8 were diagnosed with pre-capillary PH (mean pulmonary arterial pressure [mPAP] > 20 mm Hg), and 36 patients were defined as no-PH (mPAP ≤ 20 mm Hg). Three patients with >15 mm Hg of pulmonary artery wedge pressure were excluded. Receiver operating characteristic analyses for pre-capillary PH using estimated systolic PAP (esPAP) revealed an area under the curve (AUC) of 0.736, with a sensitivity and specificity of 62.5% and 86.1%, respectively, at a cutoff level of 35.0 mm Hg. The predicted percentage diffusing lung capacity for carbon monoxide (DLCO%) revealed an AUC of 0.840, with a sensitivity and specificity of 85.7% and 80.0%, respectively, at a cutoff level of 70.0%. Six pre-capillary PH patients, including one who died from PH 14 months after the first RHC, indicated exacerbations of mPAP or esPAP within 5 years. When esPAP < 35.0 mm Hg and DLCO% > 70% were met as the cutoff, none had been newly diagnosed with PH over 5 years.

CONCLUSIONS

The conventional screening tests may be useful for detecting pre-capillary PH with SSc, and both esPAP < 35.0 mm Hg and DLCO% > 70% indicated a lower risk of developing PH for at least 5 years.

Cardiovascular Manifestations of Systemic Sclerosis: An Overview of Pathophysiology, Screening Modalities, and Treatment Options

Systemic sclerosis, previously known as scleroderma, is a heterogeneous, systemic disease that is defined by its 3 pathological hallmarks: the production of autoantibodies, small vessel vasculopathy, and fibroblast dysfunction, leading to an increased deposition of extracellular matrix. We conducted a review of the available literature that covers the cardiovascular manifestations of SSc: electrical conduction abnormalities, pulmonary hypertension, pericardial disease, and atherosclerosis. Within each major category, we will discuss the definition, diagnostics, and available treatment options. Increased mortality from cardiovascular complications necessitates early screening and management. Annual screening with noninvasive modalities is encouraged. The current management of each complication generally follows the management algorithms of patients regardless of SSc status and is dependent on the severity of the patient's clinical presentation.

Metabolomic Profiles Differentiate Scleroderma-PAH From Idiopathic PAH and Correspond With Worsened Functional Capacity

BACKGROUND

The prognosis and therapeutic responses are worse for pulmonary arterial hypertension associated with systemic sclerosis (SSc-PAH) compared with idiopathic pulmonary arterial hypertension (IPAH). This discrepancy could be driven by divergence in underlying metabolic determinants of disease.

RESEARCH QUESTION

Are circulating bioactive metabolites differentially altered in SSc-PAH vs IPAH, and can this alteration explain clinical disparity between these PAH subgroups?

STUDY DESIGN AND METHODS

Plasma biosamples from 400 patients with SSc-PAH and 1,082 patients with IPAH were included in the study. Another cohort of 100 patients with scleroderma with no PH and 44 patients with scleroderma with PH was included for external validation. More than 700 bioactive lipid metabolites, representing a range of vasoactive and immune-inflammatory pathways, were assayed in plasma samples from independent discovery and validation cohorts using liquid chromatography/high-resolution mass spectrometry-based approaches. Regression analyses were used to identify metabolites that exhibited differential levels between SSc-PAH and IPAH and associated with disease severity.

RESULTS

From hundreds of circulating bioactive lipid molecules, five metabolites were found to distinguish between SSc-PAH and IPAH, as well as associate with markers of disease severity. Relative to IPAH, patients with SSc-PAH carried increased levels of fatty acid metabolites, including lignoceric acid and nervonic acid, as well as eicosanoids/oxylipins and sex hormone metabolites.

INTERPRETATION

Patients with SSc-PAH are characterized by an unfavorable bioactive metabolic profile that may explain the poor and limited response to therapy. These data provide important metabolic insights into the molecular heterogeneity underlying differences between subgroups of PAH.

Systemic sclerosis and vaccinations: a three-year register-based cohort study about vaccination rate and uptake from Liguria referral center, northwest Italy

Patients with diffused Systemic Sclerosis (dSSc) are more subject to severe respiratory complications with higher rates of intensive care unit (ICU) admission. Vaccination represents the most effective means of prevention and care for frail patients, such as SSc patients, preventing infections, reducing mortality and morbidity, and granting a better quality of life. Both vaccinations against seasonal influenza and Streptococcus pneumoniae are currently recommended by the European League Against Rheumatism (EULAR) guidelines on vaccination. The aim of this study is to give an updated analysis on S. pneumoniae and seasonal influenza vaccination coverage in a cohort of 91 patients with SSc and to investigate demographic and clinical variables significantly related to vaccine acceptance. The correlation between vaccine administration and other factors was investigated using a binomial logistic regression to evaluate the adjusted odds ratio (aOR). The patients followed up in this study reached higher percentages than the general population, passing the 75% target for both influenza and anti-pneumococcal vaccinations and reaching for influenza vaccine coverage rates of 83.8% for subjects undergoing immunosuppressive therapies and 88.9% for elderly subjects. For the latter group, it is important to emphasize the strong correlation between older age groups and vaccination acceptance.

Correlation between Microvascular Damage and Internal Organ Involvement in Scleroderma: Focus on Lung Damage and Endothelial Dysfunction

BACKGROUND

Systemic sclerosis (SSc) is an incurable connective tissue disease characterized by decreased peripheral blood perfusion due to microvascular damage and skin thickening/hardening. The microcirculation deficit is typically secondary to structural vessel damage, which can be assessed morphologically and functionally in a variety of ways, exploiting different technologies.

OBJECTIVE

This paper focuses on reviewing new studies regarding the correlation between microvascular damage, endothelial dysfunction, and internal organ involvement, particularly pulmonary changes in SSc.

METHODS

We critically reviewed the most recent literature on the correlation between blood perfusion and organ involvement.

RESULTS

Many papers have demonstrated the link between structural microcirculatory damage and pulmonary involvement; however, studies that have investigated correlations between microvascular functional impairment and internal organ damage are scarce. Overall, the literature supports the correlation between organ involvement and functional microcirculatory impairment in SSc patients.

CONCLUSIONS

Morphological and functional techniques appear to be emerging biomarkers in SSc, but obviously need further investigation.

Potential Role of JAK Inhibitors in the Treatment of Systemic Sclerosis-Associated Interstitial Lung Disease: A Narrative Review from Pathogenesis to Real-Life Data

BACKGROUND

Systemic sclerosis-associated interstitial lung disease (SSc-ILD) is one of the most relevant complications of SSc and the major cause of death. The pathogenesis of SSc-ILD involves a complex interplay of multiple cell types and different molecular pathways, with both inflammation and fibrosis as pathological hallmarks. To date, there are no treatments able to target both components of the disease. Janus kinase inhibitors (JAKinibs) represent an interesting therapeutic option because they exert both anti-inflammatory and anti-fibrotic properties.

METHODS

Here, we performed a narrative review concerning the potential role of JAKinibs in SSc-ILD to define the state of art and to evaluate the pathogenetic rationale behind this type of treatment.

RESULTS

Currently, few studies investigated SSc-ILD response to JAKinibs treatment. Data were analyzed from three clinical studies and four case reports and progression of SSc-ILD was not evident in 93.5% of patients treated with JAKinibs.

CONCLUSIONS

Available evidence of efficacy of JAKinibs in SSc-ILD is sparse but promising. JAKinibs could be an interesting treatment in SSc-ILD because of their potential inhibition of the fibrotic processes combined with their anti-inflammatory action. Moreover, JAKinibs were also shown in some studies to have a potential effect on pulmonary arterial hypertension (PAH), another threatening complication in SSc. More data are necessary to define JAKinibs role in SSc-ILD treatment.

Predicting the Progression of Very Early Systemic Sclerosis: Current Insights

Systemic sclerosis (SSc) is a complex autoimmune connective tissue disease with distinct pathological hallmarks (ie, inflammation, vasculopathy, fibrosis) that may predominate at different stages in the disease course with varying severity. Initial efforts to classify patients with SSc identified a subset of patients with very early SSc. These patients possessed signs of SSc (eg, Raynaud phenomenon, SSc specific autoantibodies and/or nailfold capillary abnormalities) without fulfilling complete SSc classification criteria. Recognizing the inherent value in early diagnosis and intervention in SSc, researchers have endeavored to identify risk factors for progression from very early SSc to definite SSc. The present review summarizes the clinical phenotype of patients with very early and early SSc. Through a scoping review of recent literature, this review also describes risk factors for progression to definite SSc with a focus on the specific clinical features that arise early in the SSc disease course (eg, diffuse cutaneous sclerosis, interstitial lung disease, esophageal dysfunction, renal crisis, cardiac involvement). In addition to clinical risk factors, this review provides evidence for how biological data (ie, serological, genomic, proteomic profiles, skin bioengineering methods) can be integrated into risk assessment models in the future. Furthering our understanding of biological features of very early SSc will undoubtedly provide novel insights into SSc pathogenesis and may illuminate new therapeutic targets to prevent progression of SSc.

Pulmonary Hypertension in Scleroderma- Evaluation and Management

Pulmonary Arterial Hypertension (PAH) is a clinical syndrome consisting of physiologic/hemodynamic criteria that are a consequence of several etiologies. Systemic Sclerosis (SSc), one of the most common causes of PAH, is an autoimmune disorder of the connective tissue leading to fibrosis that involves the skin, gastrointestinal tract, lungs, heart, kidney etc. SSc has an annual prevalence of one to five cases for every 1000 individuals and nearly 15 percent of all cases develop PAH. At its core, Pulmonary hypertension (PH) in SSc is an obliterative vasculopathy in small to medium-sized pulmonary arterioles. A host of other local and systemic mechanisms operate in concert to gradually alter the hemodynamics resulting in elevated pulmonary vascular resistance and thus right ventricular afterload. A diagnosis of PAH in SSc is virtually a death sentence, with studies reporting a mortality rate of 50 per cent in the 3 years of diagnosis. Therefore, developing and implementing a robust screening and diagnosis protocol is crucial in the fight against this pervasive disease. This review aims to summarize the current literature of PAH in SSc, with a special focus on the screening and diagnosis protocols, newer treatment options and prognostic indicators for the same.

New Era in Systemic Sclerosis Treatment: Recently Approved Therapeutics

Systemic sclerosis (SSc) is a chronic autoimmune disease with a poor prognosis. Among the various complications of SSc, treatment options for the fibrotic lesions, skin sclerosis, and SSc-associated interstitial lung disease (SSc-ILD) have been limited. However, since 2019, the efficacy and safety of nintedanib, tocilizumab, and rituximab for SSc or SSc-ILD have been demonstrated in double-blind, randomized, placebo-controlled trials, respectively. The antifibrotic agent nintedanib was approved for SSc-ILD in all regions of the United States, Europe, and Japan after the SENSCIS study confirmed that it suppressed the reduction in forced vital capacity (FVC), a measure of SSc-ILD. Tocilizumab, an anti-interleukin-6 receptor antibody, was approved for the treatment of SSc-ILD in the United States after the FocuSSced study showed that it inhibited the decrease in FVC. Rituximab, an anti-CD20 antibody, showed improvement in both modified Rodnan skin score, a measure of skin sclerosis, and FVC in the DESIRES study, and was approved in Japan for the treatment of SSc itself. With the development of these three drugs, SSc treatment is entering a new era. This paper outlines the latest advances in SSc therapeutics, focusing on nintedanib, tocilizumab, and rituximab.

Autoimmunity to Sphingosine-1-Phosphate-Receptors in Systemic Sclerosis and Pulmonary Arterial Hypertension

Context

Pulmonary arterial hypertension (PAH) is a frequent extracutaneous manifestation of systemic sclerosis (SSc). PAH is characterized by increased vasomotor tone, progressive remodeling of pulmonary arteries and arterioles, consequentially increased pulmonary vascular resistance, right heart hypertrophy, and eventually right ventricular failure. Autoimmunity against G-protein coupled receptors (GPCRs) has been implicated in the development of SSc-associated PAH. Sphingosine-1-phosphate (S1P) receptors (S1PR) present a potential, yet so far untested antigen for PAH autoimmunity, given the documented role of S1P/S1PR signaling in PAH pathogenesis.

Objective

We hypothesized that S1P receptors (S1PR) may constitute autoantigens in human patients, and that the prevalence of autoantibodies (aAb) to S1PR1, S1PR2 and S1PR3 is elevated in SSc patients and associated with PAH.

Methods

For this exploratory study, serum samples from 158 SSc patients, 58 of whom with PAH, along with 333 healthy control subjects were screened for S1PR-aAb. S1PR1-3 were expressed as fusion proteins with luciferase in human embryonic kidney cells and used to establish novel in-vitro assays for detecting and quantifying S1PR-aAb. The fusion proteins were incubated with serum samples, the aAb-S1PR complexes formed were precipitated by protein-A, washed and tested for luciferase activity. Commercial anti-S1PR-antibodies were used to verify specificity of the assays.

Results

All three assays showed dose-dependent signal intensities when tested with S1PR-subtype specific commercial antibodies. Natural aAb to each S1PR were detected in healthy controls with a prevalence of <10% each, i.e., 2.7% for S1PR1-aAb, 3.6% for S1PR2-aAb, and 8.3% for S1PR3. The respective prevalence was higher in the cohort of SSc patients without PAH, with 17.1% for S1PR1-aAb, 19.0% for S1PR2-aAb, and 21.5% for S1PR3. In the subgroup of SSc patients with PAH, prevalence of aAb to S1PR2 and S1PR3 was further elevated to 25.9% for S1PR2-aAb, and 27.6% for S1PR3. Notably, the majority of patients with positive S1PR2-aAb (60.7%) or S1PR3-aAb (71.9%) displayed interstitial lung disease.

Conclusion

S1PR1–3 can constitute autoantigens in humans, particularly in SSC patients with PAH. The potential pathophysiological significance for the etiology of the disease is currently unknown, but the elevated prevalence of S1PR2-aAb and S1PR3-aAb in SSC patients with PAH merits further mechanistic investigations.

Gastric antral vascular ectasia in systemic sclerosis: a study of its epidemiology, disease characteristics and impact on survival

BACKGROUND

To describe the epidemiology, determinants and survival impact of gastric antral vascular ectasia (GAVE) in systemic sclerosis (SSc).

METHODS

Consecutive SSc patients prospectively enrolled in the Australian Scleroderma Cohort Study (ASCS) were included. Univariable and multivariable logistic regression were used to determine the associations of GAVE with clinical manifestations and serological parameters. Kaplan-Meier (K-M) survival curves were used to estimate survival.

RESULTS

The prevalence of GAVE in this SSc cohort of 2039 SSc patients was 10.6% (n = 216) over a median follow-up period of 4.3(1.7-8.4) years. SSc patients with a history of GAVE compared with those without a history of GAVE were older at SSc onset [49.5 (40.0-58.2) vs 46.7 (36.0-56.7) years, p = 0.05]; more likely to have diffuse disease subtype (dcSSc) (35.3% vs 24.1%, p < 0.001); be negative for Scl-70, U1RNP and Scl/PM antibody (4.0% vs 16.1%, p < 0.001, 3.5% vs 7.4%, p = 0.041, 0.0% vs 2.0%, p = 0.042; and respectively) and positive for RNAP III antibody (24.9% vs 8.3%, p < 0.001). Those with GAVE had a worse HRQoL (p = 0.002). Independent determinants of GAVE included the presence of RNAP III antibody (OR 3.46, p < 0.001), absence of Scl-70 antibody (OR 0.23, p = 0.001), presence of GIT dysmotility (OR 1.64, p = 0.004), and digital ulcers; pits; or digital amputation (OR 1.59, p = 0.014).

CONCLUSIONS

GAVE is an underestimated and underappreciated SSc manifestation of SSc, which occurs with a relatively high frequency. Identifying an at-risk GAVE phenotype, as presented herein, is of practical importance as screening may prove advantageous given GAVE can be easily diagnosed and treated.

Insights on the Gut-Mesentery-Lung Axis in Pulmonary Arterial Hypertension: A Poorly Investigated Crossroad

Pulmonary arterial hypertension (PAH) is a life-threatening disease characterized by the hyperproliferation of vascular cells, including smooth muscle and endothelial cells. Hyperproliferative cells eventually obstruct the lung vasculature, leading to irreversible lesions that collectively drive pulmonary pressure to life-threatening levels. Although the primary cause of PAH is not fully understood, several studies have indicated it results from chronic pulmonary inflammation, such as observed in response to pathogens' infection. Curiously, infection by the intravascular parasite Schistosoma mansoni recapitulates several aspects of the widespread pulmonary inflammation that leads to development of chronic PAH. Globally, >200 million people are currently infected by Schistosoma spp., with about 5% developing PAH (Sch-PAH) in response to the parasite egg-induced obliteration and remodeling of the lung vasculature. Before their settling into the lungs, Schistosoma eggs are released inside the mesenteric veins, where they either cross the intestinal wall and disturb the gut microbiome or migrate to other organs, including the lungs and liver, increasing pressure. Spontaneous or surgical liver bypass via collateral circulation alleviates the pressure in the portal system; however, it also allows the translocation of pathogens, toxins, and antigens into the lungs, ultimately causing PAH. This brief review provides an overview of the gut-mesentery-lung axis during PAH, with a particular focus on Sch-PAH, and attempts to delineate the mechanism by which pathogen translocation might contribute to the onset of chronic pulmonary vascular diseases.

Impact of interstitial lung disease on the survival of systemic sclerosis with pulmonary arterial hypertension

To assess severity markers and outcomes of patients with systemic sclerosis (SSc) with or without pulmonary arterial hypertension (PAH-SSc/non-PAH-SSc), and the impact of interstitial lung disease (ILD) on PAH-SSc. Non-PAH-SSc patients from the Spanish SSc registry and PAH-SSc patients from the Spanish PAH registry were included. A total of 364 PAH-SSc and 1589 non-PAH-SSc patients were included. PAH-SSc patients had worse NYHA-functional class (NYHA-FC), worse forced vital capacity (FVC) (81.2 ± 20.6% vs 93.6 ± 20.6%, P < 0.001), worse tricuspid annular plane systolic excursion (TAPSE) (17.4 ± 5.2 mm vs 19.9 ± 6.7 mm, P < 0.001), higher incidence of pericardial effusion (30% vs 5.2%, P < 0.001) and similar prevalence of ILD (41.8% vs. 44.9%). In individuals with PAH-SSc, ILD was associated with worse hemodynamics and pulmonary function tests (PFT). Up-front combination therapy was used in 59.8% and 61.7% of patients with and without ILD, respectively. Five-year transplant-free survival rate was 41.1% in PAH-SSc patients and 93.9% in non-PAH-SSc patients (P < 0.001). Global survival of PAH-SSc patients was not affected by ILD regardless its severity. The multivariate survival analysis in PAH-SSc patients confirmed age at diagnosis, worse NYHA-FC, increased PVR, reduced DLCO, and lower management with up-front combination therapy as major risk factors. In conclusion, in PAH-SSc cohort risk of death was greatly increased by clinical, PFT, and hemodynamic factors, whereas it was decreased by up-front combination therapy. Concomitant ILD worsened hemodynamics and PFT in PAH-SSc but not survival regardless of FVC impairment.

A Narrative Review of Pathogenetic and Histopathologic Aspects, Epidemiology, Classification Systems, and Disease Outcome Measures in Systemic Sclerosis

Systemic sclerosis (SSc) is a rare systemic autoimmune disease, characterized by the presence of three main actors: vasculopathy, immune activation, and fibrosis. This pathologic process is then translated in a clinical picture with great variability among different patients in terms of type of organ involvement, disease severity and prognosis. This heterogeneity is a main feature of SSc, which, in addition to the presence of early phases of the disease characterized by mild symptoms, can explain the high difficulty in establishing classification criteria, and in defining patients' subsets and disease outcomes. The definition of disease outcomes is particularly relevant in the setting of clinical trials, where the aim is to provide reliable endpoints, able to measure the magnitude of the efficacy of a certain drug or intervention. For this reason, in the last years, increasing efforts have been done to design measures of disease activity, damage, severity, and response to treatment, often in the context of composite indexes. When considering disease outcomes, the experience of the patient represents a relevant and complementary aspect. The tools able to capture this experience, the patient-reported outcomes, have been increasingly used in the last years in clinical practice and in clinical trials, both as primary and secondary endpoints. This comprehensive narrative review on SSc will therefore cover pathogenetic and histopathologic aspects, epidemiology, classification systems, and disease outcome measures, in order to focus on issues that are relevant for clinical research and design of clinical trials.

Dysregulated Immunity in Pulmonary Hypertension: From Companion to Composer

Pulmonary hypertension (PH) represents a grave condition associated with high morbidity and mortality, emphasizing a desperate need for innovative and targeted therapeutic strategies. Cumulative evidence suggests that inflammation and dysregulated immunity interdependently affect maladaptive organ perfusion and congestion as hemodynamic hallmarks of the pathophysiology of PH. The role of altered cellular and humoral immunity in PH gains increasing attention, especially in pulmonary arterial hypertension (PAH), revealing novel mechanistic insights into the underlying immunopathology. Whether these immunophysiological aspects display a universal character and also hold true for other types of PH (e.g., PH associated with left heart disease, PH-LHD), or whether there are unique immunological signatures depending on the underlying cause of disease are points of consideration and discussion. Inflammatory mediators and cellular immune circuits connect the local inflammatory landscape in the lung and heart through inter-organ communication, involving, e.g., the complement system, sphingosine-1-phosphate (S1P), cytokines and subsets of, e.g., monocytes, macrophages, natural killer (NK) cells, dendritic cells (DCs), and T- and B-lymphocytes with distinct and organ-specific pro- and anti-inflammatory functions in homeostasis and disease. Perivascular macrophage expansion and monocyte recruitment have been proposed as key pathogenic drivers of vascular remodeling, the principal pathological mechanism in PAH, pinpointing toward future directions of anti-inflammatory therapeutic strategies. Moreover, different B- and T-effector cells as well as DCs may play an important role in the pathophysiology of PH as an imbalance of T-helper-17-cells (T_H17) activated by monocyte-derived DCs, a potentially protective role of regulatory T-cells (T_reg) and autoantibody-producing plasma cells occur in diverse PH animal models and human PH. This article highlights novel aspects of the innate and adaptive immunity and their interaction as disease mediators of PH and its specific subtypes, noticeable inflammatory mediators and summarizes therapeutic targets and strategies arising thereby.

Chronic Inflammation as the Underlying Mechanism of the Development of Lung Diseases in Psoriasis: A Systematic Review

Psoriasis is a systemic inflammatory disease caused by dysfunctional interactions between the innate and adaptive immune responses. The systemic inflammation in psoriasis may be associated with the development of comorbidities, including lung diseases. In this review, we aimed to provide a summary of the evidence regarding the prevalence of lung diseases in patients with psoriasis and the potential underlying mechanisms. Twenty-three articles published between March 2010 and June 2021 were selected from 195 initially identified records. The findings are discussed in terms of the prevalence of asthma, chronic obstructive pulmonary disease, interstitial lung disease, obstructive sleep apnea, pulmonary hypertension, and sarcoidosis in psoriasis. A higher prevalence of lung diseases in psoriasis has been confirmed in asthma, chronic obstructive pulmonary disease, obstructive sleep apnea, and pulmonary hypertension. These conditions are important as they are previously unrecognized causes of morbidity and mortality in psoriasis. The development of lung diseases in patients with psoriasis can be explained by several mechanisms, including common risk factors, shared immune and molecular characteristics associated with chronic inflammation, as well as other mechanisms. Understanding the prevalence of lung diseases in psoriasis and their underlying mechanisms can help implement appropriate preventative and therapeutic strategies to address respiratory diseases in patients with psoriasis.

Clinical phenotypes, hemodynamic characteristics and prognosis of Chinese patients with systemic sclerosis-associated precapillary pulmonary hypertension: a retrospective study

INTRODUCTION

Systemic sclerosis (SSc) is associated with interstitial lung disease (ILD) and pulmonary arterial hypertension (PAH). This study aimed to explore the prevalence, clinical features, hemodynamic characteristics and prognosis of different severity of ILD in a cohort of patients with SSc-associated precapillary pulmonary hypertension (SSc-PH) and investigate the differences between SSc-PAH and idiopathic pulmonary arterial hypertension (IPAH) patients.

METHOD

SSc-PH patients and IPAH patients, admitted to Shanghai Pulmonary Hospital (August 1, 2008-January 31, 2020) and diagnosed by right-sided heart catheterization (RHC) or echocardiography, were retrospectively included. SSc-PH patients had a baseline chest high-resolution computed tomography (HRCT), and PH classification was based on the extent of ILD. Clinical, pulmonary function, hemodynamic characteristics and survival data were extracted.

RESULTS

The study included 45 SSc-PH patients (60% had coexisting ILD and 77.8% were SSc-Group 1 PH/SSc-PAH [without ILD or with mild ILD], 22.2% were SSc-Group 3 PH/SSc-PH with severe ILD) and 52 IPAH patients. SSc-PH with ILD had lower arterial oxygen partial pressure (PaO₂) than those without ILD. Hemodynamic characteristics and survival rates were comparable between SSc-PAH with mild ILD and those without ILD. SSc-Group 3 PH had lower pulmonary vascular resistance (PVR) and more severe restrictive ventilatory dysfunction than SSc-Group 1 PH, but the survival rate was equally poor. SSc-PAH had a poorer prognosis than IPAH patients despite the better hemodynamic characteristics.

CONCLUSIONS

ILD was common in SSc-PH patients. Careful phenotyping of PH in SSc-PH patients is very important as it is imperative to recognize its impact on clinical course, treatment and survival.

KEY POINTS

• ILD was common in Chinese SSc-PH patients. • SSc-PH patients with ILD had lower PaO₂ than those without ILD. • Hemodynamic characteristics and survival rates were similar in SSc-PAH patients with mild ILD and those without ILD. • Patients in SSc-Group 3 PH had lower pulmonary vascular resistance (PVR) and more severe restrictive ventilatory dysfunction than those in SSc-Group 1 PH, but the survival rate was equally poor. SSc-PAH patients had a poorer prognosis than IPAH patients despite their better hemodynamic characteristics.

Ventricular mass discriminates pulmonary arterial hypertension as redefined at the Sixth World Symposium on Pulmonary Hypertension

Cardiac magnetic resonance (CMR) measures of right ventricular (RV) mass, volumes, and function have diagnostic and prognostic value in pulmonary arterial hypertension (PAH). We hypothesized that RV mass-based metrics would discriminate incident PAH as redefined by the lower mean pulmonary arterial pressure (mPAP) threshold of >20 mmHg at the Sixth World Symposium on Pulmonary Hypertension (6th WSPH). Eighty-nine subjects with suspected PAH underwent CMR imaging, including 64 subjects with systemic sclerosis (SSc). CMR metrics, including RV and left ventricular (LV) mass, were measured. All subjects underwent right heart catheterization (RHC) for assessment of hemodynamics within 48 h of CMR. Using generalized linear models, associations between CMR metrics and PAH were assessed, the best subset of CMR variables for predicting PAH were identified, and relationships between mass-based metrics, hemodynamics, and other predictive CMR metrics were examined. Fifty-nine subjects met 6th WSPH criteria for PAH. RV mass metrics, including ventricular mass index (VMI), demonstrated the greatest magnitude difference between subjects with versus without PAH. Overall and in SSc, VMI and RV mass measured by CMR were among the most predictive variables discriminating PAH at RHC, with areas under the receiver operating characteristic curve 0.86 and 0.83. respectively. VMI increased linearly with pulmonary vascular resistance and with mPAP in PAH, including in lower ranges of mPAP associated with mild PAH. VMI ≥ 0.37 yielded a positive predictive value of 90% for discriminating PAH. RV mass metrics measured by CMR, including VMI, discriminate incident, treatment-naïve PAH as defined by 6th WSPH criteria.

Cellular and Molecular Diversity in Scleroderma

With the increasing armamentarium of high-throughput tools available at manageable cost, it is attractive and informative to determine the molecular underpinnings of patient heterogeneity in systemic sclerosis (SSc). Given the highly variable clinical outcomes of patients labelled with the same diagnosis, unravelling the cellular and molecular basis of disease heterogeneity will be crucial to predicting disease risk, stratifying management and ultimately informing a patient-centered precision medicine approach. Herein, we summarise the findings of the past several years in the fields of genomics, transcriptomics, and proteomics that contribute to unraveling the cellular and molecular heterogeneity of SSc. Expansion of these findings and their routine integration with quantitative analysis of histopathology and imaging studies into clinical care promise to inform a scientifically driven patient-centred personalized medicine approach to SSc in the near future.

The role of TGF-β or BMPR2 signaling pathway-related miRNA in pulmonary arterial hypertension and systemic sclerosis

Pulmonary arterial hypertension (PAH) is a severe complication of connective tissue disease (CTD), causing death in systemic sclerosis (SSc). The past decade has yielded many scientific insights into microRNA (miRNAs) in PAH and SSc. This growth of knowledge has well-illustrated the complexity of microRNA (miRNA)-based regulation of gene expression in PAH. However, few miRNA-related SSc-PAH were elucidated. This review firstly discusses the role of transforming growth factor-beta (TGF-β) signaling and bone morphogenetic protein receptor type II (BMPR2) in PAH and SSc. Secondly, the miRNAs relating to TGF-β and BMPR2 signaling pathways in PAH and SSc or merely PAH were subsequently summarized. Finally, future studies might develop early diagnostic biomarkers and target-oriented therapeutic strategies for SSc-PAH and PAH treatment.

Flu and Pneumococcal Vaccine Coverage in Scleroderma Patients Still Need to Be Prompted: A Systematic Review

Systemic sclerosis (scleroderma, SSc) is an autoimmune connective tissue disease characterized by excessive production of collagen and multiorgan involvement. Scleroderma patients are at increased risk of influenza complications and pneumonia; thus, vaccinations are recommended. This systematic review evaluated the influenza and pneumococcus vaccination coverage for SSc patients. We included all studies from Pubmed reporting on influenza and pneumococcal vaccination rate in Scleroderma patients up to May 2021. The 14 studies thus selected identified a suboptimal vaccination rate in autoimmune and SSc patients, ranging from 28 to 59% for the flu vaccine, and from 11 to 58% for the pneumo vaccine in absence of specific vaccination campaigns, variously considering also other variables such as age, gender, vaccination settings, and possible vaccination campaigns. We also considered the reasons for low coverage and the approaches that might increase the vaccination rates. A lack of knowledge about the importance of vaccination in these patients and their doctors underlined the need to increase the awareness for vaccination in this patients' category. Current guidelines recommend vaccination in elderly people and people affected by particular conditions that widely overlap with SSc, yet autoimmune diseases are not always clearly mentioned. Improving this suboptimal vaccination rate with clear guidelines is crucial for SSc patients and for clinicians to immunize these categories based principally on the pathology, prior to the age. Recommendations by the immunologist and the direct link to the vaccine providers can highly improve the vaccine coverage.

Improvement with time of vascular outcomes in systemic sclerosis: a systematic review and meta-analysis study

OBJECTIVES

Vascular disease in systemic sclerosis (SSc) is associated with significant morbidity and mortality. Preliminary data may lead to the suggestion of a modifiable unified-vascular endophenotype. Our aim was to determine whether the prevalence, mortality, and severity of SSc-vascular disease have changed over time.

METHODS

We performed a systematic review and meta-analysis of the literature in PubMed 1950-2019 related to SSc-digital ulcers (DUs), pulmonary artery hypertension (PAH) and scleroderma renal crisis (SRC). We included full-text articles and extracted study characteristics and assessed risk of bias/quality. We examined the prevalence, mortality, and surrogate measures of SSc-associated vascular disease severity.

RESULTS

We included 55 studies in our meta-analysis. The pooled prevalence of DUs (41.0%), PAH (9.5%) and SRC (4.9%) remained largely stable over time. There was significant improvement in PAH 1-year (p= 0.001) and SRC mortality (P = <0.001), but not PAH 3-year (p= 0.312) or 5-year (p= 0.686) mortality. The prevalence of DU healing did not significantly change (p= 0.265). There was a trend (all P=∼0.1) towards improvement in PAH surrogates: mean pulmonary artery pressure, pulmonary vascular resistance, and right atrial pressure. For SRC, there was evidence that the overall frequency of dialysis (66.7%, p= 0.297) and permanent dialysis (34.5%, p= 0.036) increased over time.

CONCLUSION

Despite the heterogeneity and scarcity of the disease, there have been major improvements obtained in the various vascular complications in SSc leading to benefit in survival. This is supported by a trend towards improvement in several surrogate markers and demonstrates that progresses in vascular management translate into major patient benefit.

Cutaneous iontophoresis of vasoactive medications in patients with scleroderma-associated pulmonary arterial hypertension

BACKGROUND

It remains unknown whether the cutaneous microvascular responses are different between patients with scleroderma-associated pulmonary arterial hypertension (SSc-PAH) and SSc without pulmonary hypertension (PH).

METHODS

We included 59 patients with SSc between March 2013 and September 2019. We divided patients into 4 groups: (a) no PH by right heart catheterization (RHC) (n = 8), (b) no PH by noninvasive screening tests (n = 16), (c) treatment naïve PAH (n = 16), and (d) PAH under treatment (n = 19). Microvascular studies using laser Doppler flowmetry (LDF) were done immediately after RHC or at the time of an outpatient clinic visit (group b).

RESULTS

The median (IQR) age was 59 (54-68) years, and 90% were females. The responses to local thermal stimulation and postocclusive reactive hyperemia, acetylcholine, and sodium nitroprusside iontophoresis were similar among groups. The microvascular response to treprostinil was more pronounced in SSc patients without PH by screening tests (% change: 340 (214-781)) compared with SSc-PAH (naïve + treatment) (Perfusion Units (PU) % change: 153 (94-255) % [p = .01]). The response to A-350619 (a soluble guanylate cyclase (sGC) activator) was significantly higher in patients with SSc without PH by screening tests (PU % change: 168 (46-1,296)) than those with SSc-PAH (PU % change: 22 (15-57) % [p = .006]). The % change in PU with A350619 was directly associated with cardiac index and stroke volume index (R: 0.36, p = .03 and 0.39, p = .02, respectively).

CONCLUSIONS

Patients with SSc-PAH have a lower cutaneous microvascular response to a prostacyclin analog treprostinil and the sGC activator A-350619 when compared with patients with SSc and no evidence of PH on screening tests, presumably due to a peripheral reduction in prostacyclin receptor expression and nitric oxide bioavailability.

The expression profiling of microRNA in systemic sclerosis-associated pulmonary arterial hypertension

Background

The role of microRNAs (miRNAs) in the pathogenesis of systemic sclerosis-associated pulmonary arterial hypertension (SSc-PAH) remains to be fully elucidated. This study evaluated the expression profile of miRNAs in the lung tissue of patients with SSc-PAH.

Methods

Lung tissue samples were collected from 3 SSc-PAH patients and 4 healthy controls. A small RNA high throughput sequence approach was used for screening the differentially expressed miRNAs in the lung tissue samples. Real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used to validate 4 highly significant differentially expressed miRNAs. Gene Ontology and KEGG (Kyoto Encyclopedia of Genes and Genomes) enrichment analysis for mRNAs were performed using the R package clusterProfiler software.

Results

A total of 82 upregulated miRNAs and 35 downregulated miRNAs were detected in the lung tissues of patients with SSc-PAH compared with healthy controls. GO enrichment analysis demonstrated that the upregulated target genes were closely involved in biological processes such as nervous system development, anatomical structure morphogenesis, system development, cellular macromolecule metabolic processes, and cellular processes. The downregulated target genes were involved in the plasma membrane bound cell projection morphogenesis and the regulation of macromolecule metabolic processes. The KEGG enrichment analysis showed that the upregulated genes were associated with important pathways involved in cancer biology, and the target genes of the downregulated miRNAs were involved in axon guidance. High throughput sequencing and qRT-PCR revealed that hsa-miR-205-5p and hsa-miR-539-3p were differentially expressed in SSc-PAH tissue. The target genes of hsa-miR-205-5p and hsa-miR-539-3p, IRF1and ADCYAP1, respectively, were verified using the high throughput dataset GSE48149.

Conclusions

miRNAs may play an important role in the pathogenesis of SSc-PAH, and hsa-miR-205-5p and hsa-miR-539-3p may be potential therapeutic targets in patients with SSc-PAH.

The evaluation of right ventricle dyssynchrony by speckle tracking echocardiography in systemic sclerosis patients

PURPOSE

Systemic sclerosis (SSc) is associated with right ventricle (RV) remodeling and dysfunction. The primary aim of this study was to evaluate RV dyssynchrony (RV-Dys) in SSc patients using two-dimensional speckle tracking echocardiography (2D-STE).

METHODS

Fifty-five SSc patients with functional class I-II and 45 healthy controls were consecutively included and underwent 2D-STE. RV-Dys was defined as the standard deviation of time to peak strain of mid and basal segments of RV free wall and interventricular septum. SSc group was further classified according to the presence of pulmonary arterial hypertension (PAH). Patients with tricuspid regurgitant velocity >2.8 m/s with additional echocardiographic PAH signs were defined as SSc PAH (+).

RESULTS

SSc patients had lower RV longitudinal strain (RV-LS) (-17.6 ± 4.6% vs. -20.8 ± 2.8%, p < 0.001) and greater RV-Dys (49.9 ± 25.4 ms vs 24.3 ± 11.8 ms, p = 0.006) than controls despite no significant difference in conventional echocardiographic variables regarding RV function. Although SSc PAH(+) patients had lower RV-LS and higher RV-Dys than SSc PAH(-) patients, the differences were not statistically significant. The only independent predictor of RV-Dys was RV-LS (β:-0.324 [-3.89- -0.45]; p = 0.014).

CONCLUSION

SSc patients had not only reduced RV-LS but also impaired RV synchronicity even as conventional echocardiographic variables were preserved.

High-Resolution Computed Tomography: Lights and Shadows in Improving Care for SSc-ILD Patients

The diagnosis and classification of systemic sclerosis-associated interstitial lung disease (SSc-ILD) is essential to improve the prognosis of systemic sclerosis (SSc) patients. The risk-stratification of disease severity and follow-up requires a multidisciplinary approach, integrating high-resolution computed tomography (HRTC) of the lung, pulmonary function tests (PFT), along with clinical and symptomatic evaluations. The use of HRCT in detecting SSc-ILD is not so much based on a definitive validation, but rather reflects the widespread clinician recognition of dissatisfaction with other modalities. However, due to the heterogeneity of SSc-ILD and the potential absence of symptoms in early or mild disease, it is prudent to consider as many parameters as possible in the assessment and monitoring of newly diagnosed patients. An early diagnosis meets the primary goal, i.e., the prevention of disease progression. The current first line treatment regimens are mainly centered on immunosuppressive therapy. This review assesses the role HRCT plays in optimizing care and improving clinical outcomes in SSc-ILD patients.

The Role of Regulatory T Cells in Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a chronic, incurable condition characterized by pulmonary vascular remodeling, perivascular inflammation, and right heart failure. Regulatory T cells (Tregs) stave off autoimmunity, and there is increasing evidence for their compromised activity in the inflammatory milieu of PAH. Abnormal Treg function is strongly correlated with a predisposition to PAH in animals and patients. Athymic Treg-depleted rats treated with SU5416, an agent causing pulmonary vascular injury, develop PAH, which is prevented by infusing missing CD4⁺CD25^highFOXP3⁺ Tregs. Abnormal Treg activity may also explain why PAH disproportionately affects women more than men. This mini review focuses on the role of Tregs in PAH with a special view to sexual dimorphism and the future promise of Treg therapy.

Sphingosine Kinase 1 Regulates the Pulmonary Vascular Immune Response

The aberrant proliferation of pulmonary artery smooth muscle (PASMCs) cells is a defining characteristic of pulmonary arterial hypertension (PAH) and leads to increased vascular resistance, elevated pulmonary pressure, and right heart failure. The sphingosine kinase 1 (SPHK1)/sphingosine-1 phosphate/sphingosine-1 phosphate receptor 2 pathway promotes vascular remodeling and induces PAH. The aim of this study was to identify genes and cellular processes that are modulated by over-expression of SPHK1 in human PASMCs (hPASMCs). RNA was purified and submitted for RNA sequencing to identify differentially expressed genes. Using a corrected p-value threshold of <0.05, there were 294 genes significantly up-regulated while 179 were significantly down-regulated. Predicted effects of these differentially expressed genes were evaluated using the freeware tool Enrichr to assess general gene set over-representation (enrichment) and ingenuity pathway analysis (IPA™) for upstream regulator predictions. We found a strong change in genes that regulated the cellular immune response. IL6, STAT1, and PARP9 were elevated in response to SPHK1 over-expression in hPASMCs. The gene set enrichment mapped to a few immune-modulatory signaling networks, including IFNG. Furthermore, PARP9 and STAT1 protein were elevated in primary hPASMCs isolated from PAH patients. In conclusion, these data suggest a role of Sphk1 regulates pulmonary vascular immune response in PAH.

2020 Chinese Expert-based Consensus on the Diagnosis and Treatment of Connective Tissue Disease Associated Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a severe complication of connective tissue disease (CTD) and is one of the leading causes of morbidity and mortality among patients with this condition. To establish an expert-based consensus on the diagnosis and treatment of CTD-associated PAH, a multidisciplinary consensus development panel was established. The consensus panel is composed of 45 experts in rheumatology, cardiology, pulmonology, and radiology, most of whom are members of the Group of Pulmonary Vascular and Interstitial Lung Diseases (ILD) Associated with Rheumatic Diseases. The consensus development panel compiled 9 recommendations for the diagnosis and treatment of CTD-associated PAH. It covers screening, diagnosis, disease evaluation, risk assessment, the use of immunosuppressive agents, and PAH-specific therapy with a treat-to-target approach. The consensus is intended to facilitate decision-making and standardize the care of CTD-associated PAH in China.

Systemic Sclerosis-Associated Pulmonary Hypertension: Spectrum and Impact

Systemic sclerosis-associated pulmonary arterial hypertension (SSc-PAH) is a catastrophic complication of one of the most common and devastating autoimmune diseases. Once diagnosed, it becomes the leading cause of mortality among this patient population. Screening modalities and risk assessments have been designed and validated by various organizations and societies in order to identify patients early in their disease course and promptly refer them to expert centers for a hemodynamic assessment and formal diagnosis. Moreover, several large multicenter clinical trials have now included patients with SSc-PAH to assess their response to therapy. Despite an improved understanding of the condition and significant advances in supportive and targeted therapy, outcomes have remained far from optimal. Therefore, rigorous phenotyping and search for novel therapies are desperately needed for this devastating condition.

The Relationship between Pulmonary Damage and Peripheral Vascular Manifestations in Systemic Sclerosis Patients

Systemic sclerosis (SSc) is an autoimmune disease, characterized by the presence of generalized vasculopathy and tissue fibrosis. Collagen vascular disorder in SSc is due to fibroblast and endothelial cell dysfunctions. This leads to collagen overproduction, vascular impairment and immune system abnormalities and, in the last stage, multi-organ damage. Thus, to avoid organ damage, which has a poor prognosis, all patients should be carefully evaluated and followed. This is particularly important in the initial disease phase, so as to facilitate early identification of any organ involvement and to allow for appropriate therapy. Pulmonary disease in SSc mainly involves interstitial lung disease (ILD) and pulmonary arterial hypertension (PAH). High-resolution computed tomography (HRCT) and pulmonary function tests (PFT) have been proposed to monitor parenchymal damage. Although transthoracic echocardiography is the most commonly used screening tool for PAH in SSc patients, definitive diagnosis necessitates confirmation by right heart catheterization (RHC). Moreover, some studies have demonstrated that nailfold videocapillaroscopy (NVC) provides an accurate evaluation of the microvascular damage in SSc and is able to predict internal organ involvement, such as lung impairment. This review provides an overview of the correlation between lung damage and microvascular involvement in SSc patients.

Outcomes and Risk Factors of Systolic Pulmonary Artery Pressure Progression in Patients with Systemic Rheumatic Diseases: Follow-up Results from a Korean Registry

Objectives

This study aims to investigate the outcomes and risk factors associated with the progression of systolic pulmonary artery pressure (sPAP) in patients with systemic rheumatic diseases.

Patients and methods

A total of 532 patients (73 males, 459 females; median age 49 years; interquartile range (IQR), 36 to 62 years) registered with the Registry of Pulmonary Hypertension Associated with Rheumatic Diseases were included. Mortality curves were constructed using the Kaplan- Meier method and comparisons were performed using the log-rank test. A paired t-test was performed to evaluate the patients with markedly elevated sPAP between baseline and follow-up.

Results

The average follow-up duration was 31 months (IQR, 9 to 60 months). Of the patients, 196 had follow-up echocardiographs at least one year later. We defined the sPAP over 60 mmHg as markedly elevated. Patients in the increased sPAP above 60 mmHg at follow-up and persistently markedly elevated sPAP were associated with worse outcomes in all-cause mortality and pulmonary arterial hypertension-related mortality (p<0.001). In patients with systemic sclerosis, the majority of patients remained static within their pressure group or rose progressively: the patients with markedly elevated sPAP at follow-up were higher than those at baseline (32% versus 15%, p<0.01). In patients with mixed connective tissue disease (MCTD) or rheumatoid arthritis (RA), the majority of patients remained static within their pressure group or gradually improved: the patients with markedly elevated sPAP at follow-up were lower than those at baseline (RA=14% versus 29%, MCTD=5% versus 16%, p<0.05).

Conclusion

Persistently high sPAP or increase of sPAP over 60 mmHg at follow-up was associated with increased mortality. There were some differences in the progression of sPAP according to the underlying rheumatic diseases.

Safety and Efficacy of B-Cell Depletion with Rituximab for the Treatment of Systemic Sclerosis-associated Pulmonary Arterial Hypertension: A Multicenter, Double-Blind, Randomized, Placebo-controlled Trial

Rationale: Systemic sclerosis (SSc)-pulmonary arterial hypertension (PAH) is one of the most prevalent and deadly forms of PAH. B cells may contribute to SSc pathogenesis. Objectives: We investigated the safety and efficacy of B-cell depletion for SSc-PAH. Methods: In an NIH-sponsored, multicenter, double-blinded, randomized, placebo-controlled, proof-of-concept trial, 57 patients with SSc-PAH on stable-dose standard medical therapy received two infusions of 1,000 mg rituximab or placebo administered 2 weeks apart. The primary outcome measure was the change in 6-minute-walk distance (6MWD) at 24 weeks. Secondary endpoints included safety and invasive hemodynamics. We applied a machine learning approach to predict drug responsiveness. Measurements and Main Results: We randomized 57 subjects from 2010 to 2018. In the primary analysis, using data through Week 24, the adjusted mean change in 6MWD at 24 weeks favored the treatment arm but did not reach statistical significance (23.6 ± 11.1 m vs. 0.5 ± 9.7 m; P = 0.12). Although a negative study, when data through Week 48 were also considered, the estimated change in 6MWD at Week 24 was 25.5 ± 8.8 m for rituximab and 0.4 ± 7.4 m for placebo (P = 0.03). Rituximab treatment appeared to be safe and well tolerated. Low levels of RF (rheumatoid factor), IL-12, and IL-17 were sensitive and specific as favorable predictors of a rituximab response as measured by an improved 6MWD (receiver operating characteristic area under the curve, 0.88-0.95). Conclusions: B-cell depletion therapy is a potentially effective and safe adjuvant treatment for SSc-PAH. Future studies in these patients can confirm whether the identified biomarkers predict rituximab responsiveness. Clinical trial registered with www.clinicaltrails.gov (NCT01086540).

Recent advances in the management of pulmonary arterial hypertension: lessons from the upfront combination of ambrisentan and tadalafil

INTRODUCTION

The sixth World Symposium of Pulmonary Hypertension (sixth WSPH) brought to the forefront for the first time the value of earlier, aggressive management with an upfront oral combination in patients with pulmonary arterial hypertension (PAH) of low or intermediate risk. This was prompted by results from the AMBITION study (ambrisentan + tadalafil). A literature search was conducted to collect all evidence provided by upfront treatment with this combination, as well as other combinations under investigation at the time the manuscript was prepared.

AREAS COVERED

The value of an upfront oral combination with ambrisentan and tadalafil is reviewed on the basis of topics discussed at the sixth WSPH, such as evidence in different PAH etiologies, according to risk stratification and in so-called 'atypical' patients where monotherapy is still recommended. Evidence in clinical practice is also reviewed. New evidence about the value of the upfront oral combination is also commented. Finally, tendencies in primary endpoints to assess the effect of PAH-targeted therapies (time to clinical worsening and hemodynamics) and their value are also reviewed.

EXPERT OPINION

All above-mentioned aspects are put into perspective with regard to the impact of new advances on improving PAH management in clinical practice.

Sera and lungs metabonomics reveals key metabolites of resveratrol protecting against PAH in rats

Pulmonary arterial hypertension (PAH) is a type of high morbidity and mortality disease. Currently, the intrinsic metabolic alteration and potential mechanism of PAH are still not fully uncovered. Previously, we have found that polyphenol resveratrol (Rev) reversed the remodeling of the pulmonary vasculature and decreased the number of mitochondria in pulmonary arterial smooth muscle cells (PASMCs) (Lei Yu et al. (2017)). However, potential effects of Rev on the changed metabolic molecules derived from lung tissue and serum have no fully elucidated. Thus, we conducted a systematic elaboration through the metabonomics method. Various of metabolites in different pathways including amino acid metabolism, tricarboxylic acid cycle (TCA), acetylcholine metabolism, fatty acid metabolism and biosynthesis in male Wistar rats' sera and lung tissues were explored in three groups (normal group, PAH group, PAH and Rev treatment group). We found that leucine and isoleucine degradation, valine, leucine and isoleucine biosynthesis, tryptophan metabolism and aminoacyl-tRNA biosynthesis were involved in the development of PAH. Hydroxyphenyllactic, isopalmitic acid and cytosine might be significant key metabolites. Further work in this area may inform personalized treatment approaches in clinical practice of PAH through elucidating pathophysiology mechanisms of experimental verification.

Identification and Validation of Key Genes Associated With Systemic Sclerosis-Related Pulmonary Hypertension

Systemic sclerosis-associated with pulmonary arterial hypertension (SSc-PAH) is still a major cause of SSc related deaths. Early diagnosis and prompt treatment are crucial to reduce the mortality of patients with SSc-PAH. To screen the candidate biomarkers and potential therapeutic targets for SSc-PAH, we analyzed the data set (GSE33463 and GSE19617) for confirming key genes in peripheral blood mononuclear cells from SSc-PAH patients. A total of 105 SSc patients from gene expression omnibus (GEO) were included as discovery cohort (n = 69) and duplication cohort (n = 36) for screening hub genes by weighted gene co-expression network analysis (WGCNA). Furthermore, an independent validation cohort (n = 40), including healthy controls, SSc and SSc-PAH patients, was used for further validation by quantitative real-time polymerase chain reaction. The results showed that four key genes, including IFIT2, IFIT3, RSAD2, and PARP14, may serve as potential biomarkers in SSc-PAH. Also, they could be independent risk factors for SSc-PAH. In conclusion, the four key genes can be expected to become the potential therapeutic targets and early biomarkers for accurate therapy and diagnosis of SSc-PAH in the future, which also provides promising insights into the pathogenesis of SSc-PAH at the molecular level.