Pulmonary arterial hypertension in connective tissue disorders: Pathophysiology and treatment

Pulmonary manifestations of juvenile vs. adult systemic sclerosis: insights into pathophysiological and clinical features

Juvenile systemic sclerosis (jSSc), the pediatric counterpart of systemic sclerosis (SSc), is a rare autoimmune disorder characterized by vasculopathy and fibrotic disorders. It ranks among the rheumatologic diseases with the highest rates of morbidity and mortality, predominantly impacting females. Although a universally accepted classification for jSSc remains elusive, a provisional classification proposed in 2007 integrates major and minor criteria, reflecting the involvement of diverse organs and tissues. Pulmonary manifestations are relatively common in jSSc, occurring in 36% to 55% of cases. Particularly lung complications include children s interstitial lung disease (chILD), pulmonary arterial hypertension (PAH) and nodules. The aim of this paper is to describe the main pulmonary manifestations of patients with jSSc in relation to SSc, highlighting fundamental pathophysiological, and clinical features based on the latest literature data.

Identifying the genetic association between rheumatoid arthritis and the risk of pulmonary arterial hypertension

Epidemiological and observational studies have indicated an association between rheumatoid arthritis (RA) and pulmonary arterial hypertension (PAH). However, consistent conclusions have not been reached due to various limitations. In order to determine whether RA and PAH are causally related, we conducted a Mendelian randomization (MR) study with two samples. Data for overall RA (13,621 cases and 262,844 controls), seropositive RA (5103 cases and 402,554 controls), seronegative RA (4192 cases and 311,210 controls), and PAH (248 cases and 289,117 controls) derived from the FinnGen consortium. The inverse variance weighted, along with four other effective methodologies, were employed to comprehensively infer the causal relationships between RA and PAH. To assess the estimation's robustness, a number of sensitivity studies were performed. Causal genetic association was found between seropositive RA and decreased risk of PAH (odds ratio (OR) = 0.812, 95% confidence interval (CI) = 0.687-0.959, p = 0.042), while no causal relationship was found between overall RA or seronegative RA and PAH (OR = 0.871, 95% CI = 0.645-1.175, p = 0.548; OR = 0.791, 95%CI = 0.471-1.328, p = 0.374, respectively). We are the first to use MR analysis to explore the causal relationship between RA and PAH, revealing a decreased risk of PAH in individuals with seropositive RA. Key Points • There is a notable genetic association between seropositive RA and a decreased risk of developing PAH. • No significant association was observed between overall RA or seronegative RA and the risk of PAH. • RA represents a heterogeneous disease, with its seropositive or seronegative forms exhibiting distinct genetic characteristics.

Searching for Old and New Small-Molecule Protein Kinase Inhibitors as Effective Treatments in Pulmonary Hypertension-A Systematic Review

Treatment options for pulmonary arterial hypertension (PAH) have improved substantially in the last 30 years, but there is still a need for novel molecules that can regulate the excessive accumulation of pulmonary artery smooth muscle cells (PASMCs) and consequent vascular remodeling. One set of possible candidates are protein kinases. The study provides an overview of existing preclinical and clinical data regarding small-molecule protein kinase inhibitors in PAH. Online databases were searched from 2001 to 2023 according to PRISMA. The corpus included preclinical studies demonstrating alterations in at least one PH-related parameter following chronic exposure to an individual protein kinase inhibitor, as well as prospective clinical reports including healthy adults or those with PAH, with primary outcomes defined as safety or efficacy of an individual small-molecule protein kinase inhibitor. Several models in preclinical protocols (93 papers) have been proposed for studying small-molecule protein kinase inhibitors in PAH. In total, 51 kinase inhibitors were tested. Meta-analysis of preclinical results demonstrated seralutinib, sorafenib, fasudil hydrochloride, and imatinib had the most comprehensive effects on PH with anti-inflammatory, anti-oxidant, and anti-proliferative potential. Fasudil demonstrated more than 70% animal survival with the longest experimental period, while dasatinib, nintedanib, and (R)-crizotinib could deteriorate PAH. The substances targeting the same kinases often varied considerably in their activity, and such heterogeneity may be due to the variety of causes. Recent studies have addressed the molecules that affect multiple networks such as PDG-FRα/β/CSF1R/c-KIT/BMPR2 or FKBP12/mTOR. They also focus on achieving a satisfactory safety profile using innovative inhalation formulations Many small-molecule protein kinase inhibitors are able to control migration, proliferation and survival in PASMCs in preclinical observations. Standardized animal models can successfully reduce inter-study heterogeneity and thereby facilitate successful identification of candidate drugs for further evaluations.

Antibody predictors of mortality and lung function trends in myositis spectrum interstitial lung disease

OBJECTIVES

The impact of autoantibody profiles on the prognosis for idiopathic inflammatory myositis-associated interstitial lung disease (IIM-ILD) and myositis spectrum ILD with myositis-specific antibodies (MSAs) remains unclear. This retrospective cohort study examined whether serological profiles were associated with mortality or longitudinal lung function change.

METHODS

The baseline clinical/demographic characteristics and follow-up lung function data of consecutive adult patients with IIM-ILD or interstitial pneumonia with autoimmune features (IPAF) positive for MSAs (IPAF-MSA) were extracted from three hospitals. Univariate and multivariate Cox proportional hazards analyses were used to compare mortality between groups of patients with different autoantibodies. Regression models were used to analyse their lung function trends.

RESULTS

Of the 430 included patients, 81% met the IIM criteria, and the remaining 19% were diagnosed with IPAF-MSA. On univariate analysis, the risk factors associated with mortality included higher age, Charlson Comorbidity Index, and CRP; and lower BMI, baseline TLCO% and FEV1%. Compared with anti-MDA5 negativity, anti-MDA5 positivity (MDA5+) was associated with higher mortality in the first 3 months [hazard ratio (HR) 65.2, 95% CI 14.1, 302.0], while no significant difference was seen thereafter (HR 0.55, 95% CI 0.14, 2.28). On multivariate analysis, combined anti-synthetase antibodies were associated with a reduced risk of mortality (HR 0.63), although individually, mortality was reduced in patients with anti-Jo1+ (HR 0.61, 95% CI 0.4-0.87) and increased in patients with anti-PL7+ (HR 2.07, 95% CI 1.44-2.99). Anti-MDA5+ was associated with slow improvement in %FVC over the first 3 years, while anti-PL7+ was linked with a slow decline from 12 months onwards.

CONCLUSION

Among the autoantibody profiles in myositis spectrum disorders, anti-MDA5+ and anti-PL7+ conferred higher mortality risks in patients with IIM-ILD. Survivors of an early peak of mortality in anti-MDA5+ disease appeared to have a favourable prognosis.

Sex Dimorphism in Pulmonary Arterial Hypertension Associated With Autoimmune Diseases

Pulmonary hypertension is a rare, incurable, and progressive disease. Although there is increasing evidence that immune disorders, particularly those associated with connective tissue diseases, are a strong predisposing factor in the development of pulmonary arterial hypertension (PAH), there is currently a lack of knowledge about the detailed molecular mechanisms responsible for this phenomenon. Exploring this topic is crucial because patients with an immune disorder combined with PAH have a worse prognosis and higher mortality compared with patients with other PAH subtypes. Moreover, data recorded worldwide show that the prevalence of PAH in women is 2× to even 4× higher than in men, and the ratio of PAH associated with autoimmune diseases is even higher (9:1). Sexual dimorphism in the pathogenesis of cardiovascular disease was explained for many years by the action of female sex hormones. However, there are increasing reports of interactions between sex hormones and sex chromosomes, and differences in the pathogenesis of cardiovascular disease may be controlled not only by sex hormones but also by sex chromosome pathways that are not dependent on the gonads. This review discusses the role of estrogen and genetic factors including the role of genes located on the X chromosome, as well as the potential protective role of the Y chromosome in sexual dimorphism, which is prominent in the occurrence of PAH associated with autoimmune diseases. Moreover, an overview of animal models that could potentially play a role in further investigating the aforementioned link was also reviewed.

Harmonising cellular conversations: decoding the vital roles of extracellular vesicles in respiratory system intercellular communications

Extracellular vesicles (EVs) released by various cells play crucial roles in intercellular communication within the respiratory system. This review explores the historical context and significance of research into extracellular vesicles. Categorised into exosomes (sized 30-150 nm), microvesicles (sized 50-1000 nm) and apoptotic bodies (sized 500-2000nm), based on their generation mechanisms, extracellular vesicles carry diverse cargoes of biomolecules, including proteins, lipids and nucleic acids. Respiratory ailments are the primary contributors to both mortality and morbidity across various populations globally, significantly impacting public health. Recent studies have underscored the pivotal role of extracellular vesicles, particularly their cargo content, in mediating intercellular communication between lung cells in respiratory diseases. This comprehensive review provides insights into extracellular vesicle mechanisms and emphasises their significance in major respiratory conditions, including acute lung injury, COPD, pulmonary hypertension, pulmonary fibrosis, asthma and lung cancer.

Towards a Better Prognosis in Patients with Systemic Sclerosis-Related Pulmonary Arterial Hypertension: Recent Developments and Perspectives

Precapillary pulmonary hypertension (PH) is a significant complication of systemic sclerosis (SSc). It represents one of the leading causes of morbidity and mortality, correlating with a significantly dismal prognosis and quality of life. Despite advancements in the management of patients with pulmonary arterial hypertension associated with SSc (SSc-PAH), no significant improvement has been reported in survival of patients with precapillary SSc-PH associated with extensive lung parenchyma disease. International expert consensus and guidelines for the management of PH recommend annual screening of SSc patients for early detection of pre-capillary PH. The implementation of screening algorithms capable of identifying patients with a high likelihood of developing PH could help limit unnecessary right-heart catheterization procedures and prevent significant delay in diagnosis. Furthermore, early initiation of up-front combination targeted therapy in patients with PAH has shown increase in survival rates, indicating that timely and aggressive medical therapy is key for stabilizing and even improving functional class, hemodynamic parameters and 6 min walking distance (6MWD) in this population. Further research is warranted into the benefit of PAH-targeted therapies in patients with PH associated with lung disease. Lastly, we discuss the potential role of immunosuppression using biologic agents in the therapeutic management of precapillary PH in SSc patients.

The role of immune cells in the pathogenesis of connective tissue diseases-associated pulmonary arterial hypertension

Connective tissue diseases-related pulmonary arterial hypertension (CTD-PAH) is a disease characterized by an elevated pulmonary artery pressure that arises as a complication of connective tissue diseases. The number of patients with CTD-PAH accounts for 25.3% of all PAH patients. The main pathological features of CTD-PAH are thickening of intima, media and adventitia of pulmonary arterioles, increased pulmonary vascular resistance, autoimmune activation and inflammatory reaction. It is worth noting that abnormal immune activation will produce autoantibodies and release cytokines, and abnormal immune cell recruitment will promote inflammatory environment and vascular remodeling. Therefore, almost all forms of connective tissue diseases are related to PAH. In addition to general therapy and targeted drug therapy for PAH, high-dose glucocorticoid combined with immunosuppressant can quickly alleviate and stabilize the basic CTD-PAH disease. Given this, the development of therapeutic approaches targeting immune dysregulation and heightened inflammation is recognized as a promising strategy to prevent or reverse the progression of CTD-PAH. This review explores the potential mechanisms by which immune cells contribute to the development of CTD-PAH and examines the clinical application of immunosuppressive therapies in managing CTD-PAH.

Prognostic impact of right atrial strain in systemic lupus erythematosus with pulmonary arterial hypertension

OBJECTIVE

The aim of this study was to assess right atrial (RA) function, including RA phase strain, via speckle-tracking echocardiography (STE) in a cohort of systemic lupus erythematosus (SLE) patients with pulmonary arterial hypertension (PAH) and in particular to explore the relationship between RA phase strain and the occurrence of cardiovascular events.

METHODS

STE analyses of RA function were evaluated in patients with SLE-PAH and in 33 healthy control subjects. Clinical associations, serum biomarkers, echocardiographic data, survival times, and adverse cardiovascular events were evaluated.

RESULTS

A total of 66 patients with SLE-PAH were enrolled; they were divided into two groups based on the occurrence of adverse clinical events. RA phase strain was significantly reduced in patients with events than in patients without events. The endpoint was defined as the combined outcome of all-cause mortality, right heart failure, and rehospitalization due to disease progression. During a mean follow-up of 17.2 ± 9.9 months, 23 patients (35%) reached the endpoint. Compared with patients with RA reservoir strain (RASr) ≥33.45%, patients with RASr < 33.45% had more adverse long-term outcomes (log rank p < .0001). RASr was independently associated with adverse clinical outcomes according to multivariate analysis (p = .010).

CONCLUSION

Our data suggest that RA function has prognostic value for SLE-PAH patients, and strain analysis revealed that the worse the RA function is, the worse the prognosis.

Prevalence, patient characteristics and treatment patterns among systemic lupus erythematosus-pulmonary arterial hypertension patients in real-world clinical practice: A retrospective analysis of Medical Data Vision Database in Japan

OBJECTIVES

Real-world evidence regarding prevalence, patient characteristics, and treatment patterns for pulmonary arterial hypertension (PAH) related to systemic lupus erythematosus (SLE) in Japan is limited.

METHODS

We conducted a retrospective study analysing Japan's Medical Data Vision database from April 2008 to September 2020. Prevalence, incidence, patient characteristics, treatment patterns, and use of vasodilators by treatment line were evaluated.

RESULTS

The prevalence of PAH was 0.392% in SLE patients (n = 114/29,077). Cumulative incidence was 0.53% (3 years) and 0.77% (5 years). Of 114 SLE-PAH patients, 49% developed PAH <1 year from SLE diagnosis. SLE-PAH patients were predominantly females (88% vs. 72%), had a lower mean age at SLE diagnosis (53 vs. 56 years), and had more severe SLE (61% vs. 25%) than non-PAH-SLE patients. Glucocorticoids (58%) and vasodilators (27%) were preferred first-line monotherapy for SLE-PAH. A combination of glucocorticoids and immunosuppressants (19%) was the predominant first-line combination therapy. Endothelin receptor antagonists (40% and 44%) and nitric oxide analogues (31% and 40%) were dominant first- and second-line vasodilators.

CONCLUSIONS

SLE-PAH patients were predominantly females, were younger at diagnosis, and had more severe SLE than non-PAH-SLE patients. Most were diagnosed <1 year of SLE diagnosis. In Japan's real-world practice, the initial treatment goal is SLE management, while vasodilators are preferred in advanced diseases, as per the Medical Data Vision database.

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.

The prognosis and management of reclassified systemic lupus erythematosus associated pulmonary arterial hypertension according to 2022 ESC/ERS guidelines

BACKGROUND AND AIMS

The 2022 European Society of Cardiology/European Respiratory Society (ESC/ERS) guideline has recently revised the hemodynamic definition of pulmonary arterial hypertension. However, there is currently limited research on the prognosis and treatment of system lupus erythematosus-associated pulmonary arterial hypertension (SLE-PAH) patients that have been reclassified by the new hemodynamic definition. This study aims to analyze the prognosis of newly reclassified SLE-PAH patients and provide recommendations for the management strategy.

METHODS

This retrospective study analyzed records of 236 SLE-PAH patients who visited Peking Union Medical College Hospital (PUMCH) from 2011 to 2023, among whom 22 patients were reclassified into mild SLE-PAH (mean pulmonary arterial pressure (mPAP) of 21-24 mmHg, pulmonary vascular resistance (PVR) of 2-3 WU, and PAWP ≤ 15 mmHg) according to the guidelines and 14 were defined as unclassified SLE-PAH patients (mPAP 21-24 mmHg and PVR ≤ 2 WU). The prognosis was compared among mild SLE-PAH, unclassified SLE-PH, and conventional SLE-PAH patients (mPAP ≥ 25 mmHg and PVR > 3WU). Besides, the effectiveness of pulmonary arterial hypertension (PAH)-specific therapy was evaluated in mild SLE-PAH patients.

RESULTS

Those mild SLE-PAH patients had significantly longer progression-free time than the conventional SLE-PAH patients. Among the mild SLE-PAH patients, 4 did not receive PAH-specific therapy and had a similar prognosis as patients not receiving specific therapy.

CONCLUSIONS

This study supports the revised hemodynamic definition of SLE-PAH in the 2022 ESC/ERS guideline. Those mild and unclassified SLE-PH patients had a better prognosis, demonstrating the possibility and significance of early diagnosis and intervention for SLE-PAH. This study also proposed a hypothesis that IIT against SLE might be sufficient for those reclassified SLE-PAH patients.

Interstitial Lung Disease in Patients with Mixed Connective Tissue Disease: A Retrospective Study

Objective

To investigate the clinical features, severity and prognosis of interstitial lung disease (ILD) in patients with mixed connective tissue disease (MCTD).

Methods

We performed a retrospective study on clinical data of MCTD patients admitted to China-Japan Friendship Hospital between October 2012 and October 2022. Data including long-term follow-up were retrieved from medical records. We compared MCTD patients with and without ILD in terms of clinical features, laboratory and imaging findings, severity and treatment response.

Results

A total of 59 patients were included, with a mean age of 46 years, among which 91.5% (n = 54) were females. Symptoms of pulmonary involvement were present in 44 patients (74.6%, 95% CI: 62.3-84.9%). Based on lung high-resolution computed tomography (HRCT), ILD was diagnosed in 39 (66.1%) patients, among which 31 (79.5%) showed nonspecific interstitial pneumonia (NSIP) as the radiological pattern, 21 (53.9%) showed a reticulation pattern, while 24 (61.5%) showed ground glass opacity (GGO). Eight (13.6%) patients had pulmonary arterial hypertension (PAH), and 7 (11.9%) had pleural effusions. Based on pulmonary function tests (PFTs), 27 patients were divided into the mild 13 (48.1%) and moderate 14 (51.9%) groups. Multivariate analysis showed that gastroesophageal reflux (GER; OR=5.28, p=0.010) and cough (OR=4.61, p=0.043) were the predictive factors for ILD. With a median follow-up of 50 months, the mortality rate was 2.38%.

Conclusion

ILD is common in MCTD patients, with NSIP as the common imaging pattern. Patients with GER and cough are relevant factors in the development of ILD. The majority of MCTD patients with ILD are mild to moderate in severity.

Significant nailfold capillary loss and late capillaroscopic pattern are associated with pulmonary arterial hypertension in systemic sclerosis

OBJECTIVE

To evaluate differences in nailfold videocapillaroscopy (NVC) findings between SSc patients with and without a diagnosis of pulmonary arterial hypertension (PAH).

METHODS

One hundred and ten SSc patients were enrolled in this cross-sectional, case-control, multicentre study. Patients were divided into cases (SSc-PAH confirmed by right heart catheterization) and controls (SSc-nonPAH with low probability of PAH). NVC patterns (early, active and late) and morphological parameters (microvascular density, non-specific abnormalities, giant capillaries, micro-haemorrhages, avascular areas) were considered using a semiquantitative scoring system.

RESULTS

SSc-PAH patients showed higher frequencies of late pattern (P < 0.01), non-specific abnormalities (P < 0.01), lower capillary density (P < 0.01), higher avascular areas (P < 0.01) and a higher mean NVC score (P < 0.01). Contrarily, the early/active pattern (P < 0.01) and a higher rate of micro-haemorrhages (P = 0.04) were more frequent in non-PAH patients. By a multivariate analysis, SSc-PAH patients, compared with non-PAH, had more non-specific abnormalities [27/55, 49.1% vs 10/55, 18.2%; adjusted odd ratio (OR) 16.89; 95% CI: 3.06, 93.16], a lower capillary density (grade 3, 20/55, 36.4% vs 5/55, 9.1%; adjusted OR 38.33; 95% CI: 2.34, 367.80) and avascular areas (18/55, 32.7% vs 10/55, 18.2%; adjusted OR 16.90; 95% CI: 2.64, 44.35). A correlation was found between the mean pulmonary arterial pressure and avascular areas (P < 0.01), capillary density (P < 0.01) and non-specific abnormalities (P < 0.01). A clinical model including the NVC variables may be able to predict a diagnosis of PAH.

CONCLUSION

Our results indicate that the distinctive peripheral microcirculatory injury of SSc, i.e. capillary loss and morphological abnormalities, appear more severe and pronounced in patients with SSc-PAH.

Clinical use of macitentan in the treatment of connective tissue disease-associated pulmonary arterial hypertension

Background

Connective tissue disease (CTD) is the second most common cause of the pulmonary arterial hypertension (PAH). Currently, clinical data concerning CTD-PAH is scarce. Our study aimed to assess the efficacy and safety of macitentan in the treatment of CTD-PAH.

Methods

In this retrospective study, patients diagnosed with CTD-PAH at The First Affiliated Hospital of Soochow University from April 2020 to November 2021 were included. Of the patients, 9 were switched to macitentan monotherapy whereas 23 received initial combination therapy. The mean follow-up time was 24 weeks. Six-minute walking distance (6MWD), World Health Organization functional class (WHO-FC), serum N-terminal pro-brain natriuretic peptide (NT-proBNP), and echocardiography parameters before and after medication were assessed. Adverse reactions were also recorded and compared.

Results

After 24 weeks of treatment, 6MWD, NT-proBNP, systolic pulmonary artery pressure (sPAP) estimated by ultrasound, tricuspid regurgitation pressure gradient (TRPG) and tricuspid annular plane systolic excursion (TAPSE) in the macitentan monotherapy group revealed significant differences (Z=-2.67, Z=-2.67, t=6.20, t=5.60, t=-3.04, P<0.05). There were no statistically significant differences in right ventricular diameter (RVD), right atrial diameter (RAD), ascending aortic root inner diameter (AAO) and left ventricular end-diastolic diameter (LVEDd) (P>0.05). After 24 weeks of medication, the number of patients with WHO-FC grade III/IV symptoms decreased from 6 to 3, 1 to 0 respectively (P<0.05), and that of patients with WHO-FC grade I/II symptoms increased from 0 to 2, 2 to 4 respectively(P<0.05). After 24 weeks of treatment, 6MWD, NT-proBNP, LVEDd, sPAP and TRPG in the macitentan combined with sildenafil treatment group revealed statistically significant differences (Z=-4.11, Z=-3.74, Z=-3.83, t=6.88, t=6.54, P<0.001). Significant differences in RVD, RAD, and TAPSE were found (t=3.46, t=3.69, t=-3.12, P<0.05). There were no statistically significant variances in AAO between the groups (P>0.05). The number of patients with WHO-FC grade III/IV symptoms decreased from 16 to 8, 5 to 0 respectively (P<0.05), and that of patients with WHO-FC grade I/II symptoms increased from 0 to 1, 2 to 14 respectively (P<0.001). There were no statistically significant differences before and after treatment in 6MWD, NT-proBNP, RVD, RAD, AAO, LVEDd, sPAP, TRPG and TAPSE between the two groups (P>0.05). There were no statistically significant differences in alanine aminotransferase (ALT), aspartate aminotransferase (AST), serum creatinine (Scr) and hemoglobin (Hb) between 0 and 24 weeks (P>0.05).

Conclusions

Exercise tolerance and cardiac function in patients with CTD-PAH were significantly improved after treatment with macitentan, which was well tolerated. Therefore, macitentan may be an effective and safe targeted drug for CTD-PAH.

Right ventricular-pulmonary arterial coupling ratio derived from 3-dimensional echocardiography predicts outcomes in systemic lupus erythematosus-associated pulmonary arterial hypertension patients

BACKGROUND

Systemic lupus erythematosus (SLE) is a complex autoimmune connective tissue disease (CTD) that is an important cause of devastating pulmonary arterial hypertension (PAH), and persistent progression of PAH can lead to right heart failure, predicting a poor prognosis for SLE patients. Right ventricular-pulmonary arterial (RV-PA) coupling with echocardiography has been demonstrated to be a noninvasive alternative method for evaluating PAH patients' predictive outcomes. Whether the ratio of right ventricular stroke volume (RVSV) to right ventricular end-systolic volume (RVESV) measured by three-dimensional echocardiography (3DE) is a new index of RV-PA coupling has not been discussed as a new predictor for the clinical outcome of systemic lupus erythematosus-associated pulmonary arterial hypertension (SLE-PAH).

METHODS

From June 2019 to February 2023, 46 consecutive patients with SLE-PAH were enrolled prospectively, and their clinical data and echocardiographs were studied and analyzed. The control group consisted of 30 healthy subjects matched for age, sex, and body surface area (BSA). The main endpoints of this study were a composite of all-cause mortality and adverse clinical events. Baseline clinical characteristics and echocardiographic assessments were analyzed.

RESULTS

During a median of 24 months (IQR 18-31), 16 of 46 SLE-PAH patients (34.7%) experienced endpoint-related events. At baseline, patients who experienced mortality or adverse events had a worse WHO functional class (WHO FC) and lower anti-double-stranded DNA (dsDNA) antibody levels. The right ventricular (RV) systolic dysfunction in SLE-PAH subjects was significantly worse than that in the healthy control group, especially in SLE-PAH patients in the endpoint event group. Compared to controls, patients with SLE-PAH had a lower RVSV/RVESV ratio. In the group comparison, patients who had experienced an endpoint event had a sequentially worse ratio (1.86 (1.65-2.3) versus 1.30 (1.09-1.46) versus 0.64 (0.59-0.67), p < .001). There were statistically significant associations between the RVSV/RVESV ratio to routine RV systolic function and clinical parameters. The RVSV/RVESV ratio was negatively correlated with the WHO FC (r = -0.621, p < .001) and positively correlated with the anti-dsDNA level. The ROC curve showed that the optimal cutoff for RVSV/RVESV < 0.712 determined a higher risk of poor prognosis. Kaplan‒Meier survival curves showed that an RVSV/RVESV ratio >0.712 was associated with more favorable long-term outcomes.

CONCLUSIONS

The 3DE-derived SV/ESV ratio as a noninvasive alternative surrogate of RV-PA coupling was an eximious indicator for identifying endpoint events in SLE-PAH patients and can provide a diagnostic basis for clinical intervention.

Pulmonary Hypertension in Underrepresented Minorities: A Narrative Review

Minoritized racial and ethnic groups suffer disproportionately from the incidence and morbidity of pulmonary hypertension (PH), as well as its associated cardiovascular, pulmonary, and systemic conditions. These disparities are largely explained by social determinants of health, including access to care, systemic biases, socioeconomic status, and environment. Despite this undue burden, minority patients remain underrepresented in PH research. Steps should be taken to mitigate these disparities, including initiatives to increase research participation, combat inequities in access to care, and improve the treatment of the conditions associated with PH.

Economic Burden of Delayed Diagnosis in Patients with Pulmonary Arterial Hypertension (PAH)

BACKGROUND

The aim of this study was to assess health care resource utilization (HRU) and costs associated with delayed pulmonary arterial hypertension (PAH) diagnosis in the United States.

METHODS

Eligible adults with newly diagnosed PAH from Optum's de-identified Clinformatics® Data Mart Database (2016-2021) were assigned to mutually exclusive cohorts based on time between first PAH-related symptom and first PAH diagnosis (i.e., ≤12 months' delay, >12 to ≤24 months' delay, >24 months' delay). All-cause HRU and health care costs per patient per month (PPPM) were assessed during the first year following diagnosis and compared across cohorts using regression analysis adjusted for baseline covariates. Sensitivity analyses were conducted to assess outcomes during all available follow-up post-diagnosis.

RESULTS

Among 538 patients (mean age: 65.6 years; 60.6% female), 60.8% had ≤12 months' delay, 23.4% had a delay of >12 to ≤24 months, and 15.8% had >24 months' delay. Compared with ≤12 months, delays of >12 to ≤24 months and >24 months were associated with increased hospitalizations (incidence rate ratio [95% confidence interval]: 1.40 [1.11-1.71] vs 1.71 [1.29-2.12]) and outpatient visits (1.17 [1.06-1.30] vs 1.26 [1.08-1.41]). Longer delays were also associated with more intensive care unit (ICU) stays and 30-day readmissions. Diagnosis delays translated into excess costs PPPM of US$3986 [1439-6436] for >12 to ≤24 months and US$5366 [2107-8524] for >24 months compared with ≤12 months' delay; increased hospitalization costs (US$3248 [1108-5135] and US$4048 [1401-6342], respectively) being the driver. Sensitivity analyses yielded similar trends.

CONCLUSIONS

Delayed PAH diagnosis is associated with significant incremental economic burden post-diagnosis, driven by hospitalizations including ICU stays and 30-day readmissions, highlighting the need for increased awareness and a potential benefit of earlier screening.

Real-World Treatment Patterns Among Patients with Connective Tissue Disorder-Related Pulmonary Arterial Hypertension in the United States: A Retrospective Claims-Based Analysis

INTRODUCTION

Connective tissue disorders (CTDs) are the most frequent diseases associated with pulmonary arterial hypertension (PAH). Despite advances in treatment, the prognosis of CTD-related PAH remains poor. To help identify areas for improvement in the management of CTD-related PAH, this study assessed real-world PAH treatment patterns in this population in the US.

METHODS

Eligible adult patients with PAH initiated on a PAH treatment (index date: 1st initiation date) were identified from Optum's de-identified Clinformatics® Data Mart Database (10/01/2015-09/30/2021) and categorized into mutually exclusive cohorts (CTD + PAH; PAH) based on the presence of CTD diagnosis claims. Treatment patterns were assessed from the index date to the earliest of death or end of continuous insurance eligibility, or data availability. Treatment persistence was assessed using Kaplan-Meier analysis.

RESULTS

A total of 4751 patients were included (CTD + PAH: n = 728, mean follow-up of 18.8 months; PAH: n = 4023, mean follow-up of 19.6 months). For both cohorts, the most common first treatment regimens were sildenafil (CTD + PAH: 38.7%; PAH: 51.5%), tadalafil (10.0%; 9.4%), and macitentan (8.1%; 5.4%) monotherapy; these were also the most frequent agents included in any of the first 3 treatment regimens. Combination therapy was more frequent in the CTD + PAH versus PAH cohort (any regimen: 40.9% vs. 27.2%; 1st treatment regimen: 26.9% vs. 18.5%; 2nd: 52.8% vs. 42.0%; 3rd: 55.2% vs. 48.5%). Treatment persistence was similar across cohorts and the first three treatment regimens, with persistence rates ranging from 42.6 to 49.7% at 12 months.

CONCLUSIONS

Treatment patterns were generally similar between the CTD + PAH and PAH cohorts, although combination therapy was more frequent in the CTD + PAH cohort. Both cohorts may benefit from broader use of all available PAH treatment classes, including combination therapy. Considering the life-threatening nature of PAH, our findings also highlight the need to address the low persistence rates with PAH therapies regardless of etiology.

Pulmonary hypertension in connective tissue diseases: epidemiology, pathogenesis, and treatment

Pulmonary hypertension (PH) is a clinical condition characterized by increased pulmonary arterial pressure arising from a heterogeneous range of diseases that has a deteriorating effect on the quality of life and may cause early mortality if left untreated. Connective tissue disorders (CTD)-associated PH is the second most common cause of pulmonary arterial hypertension (PAH), after the idiopathic form, categorized as group I. Systemic scleroderma (SSc) accounts for 75% of CTD-associated PH cases. Although SSc ranks first place for CTD-associated PH, SSc is followed by systemic lupus erythematosus (SLE) and mixed connective tissue disease (MCTD), having a lesser frequency of PH occurrence, while it occurs as a rare complication in cases with rheumatoid arthritis (RA) and inflammatory myositis. PH may also occur during non-SSc CTDs and even other rheumatic diseases, including Behcet's disease and adult-onset Still's disease, albeit to a lesser extent. The prognosis of CTD-associated PH is worse than the other forms of PH. Although, as in idiopathic pulmonary arterial hypertension (IPAH), the mechanism of CTD-related PH is associated with an increase in vasoconstrictors like endothelin-1 and a decrease in vasodilators like prostacyclin and nitric oxide production, inflammation, and autoimmune mechanisms also play a role in the development and progression of PH. This may lead to the involvement of more than one mechanism in CTD-associated PH. Knowing which mechanism is dominant is very important in determining the treatment option. This review will primarily focus on the epidemiology, risk factors, and prognosis of PH that develops during rheumatic diseases; the pathogenesis and treatment will be briefly mentioned in light of the newly published guidelines. Key Points • Pulmonary arterial hypertension (PAH) associated with connective tissue disease (CTD) in Western countries is the second most common type of PAH after idiopathic PAH (IPAH). • CTD-PH can be seen most often in systemic scleroderma (SSc), less in systemic lupus erythematosus (SLE), mixed CTD (MCTD), and rarely in other CTDs. • While current guidelines recommend annual transthoracic echocardiography as a screening test for asymptomatic SSc patients, screening for PH is not advised in the absence of symptoms suggestive of PH in other CTDs. • CTD-PH treatment can be divided into specific vasodilator PH treatments and immunosuppressive therapy. Current treatment guidelines recommend the same treatment algorithm for patients with CTD-associated PH as for patients with IPAH. Several case series have shown the beneficial effect of immunosuppressive agents in patients with SLE-PH and MCTD-PH.

Connective tissue disease-associated pulmonary hypertension: A comprehensive review

Connective tissue diseases (CTDs) can be associated with various forms of pulmonary hypertension, including pulmonary arterial hypertension (PAH), pulmonary veno-occlusive disease, pulmonary venous hypertension, interstitial lung disease-associated pulmonary hypertension, chronic thromboembolic pulmonary hypertension, and sometimes a combination of several processes. The prevalence of PAH varies among the different CTDs, with systemic sclerosis (SSc) having the highest at 8%-12%. The most recent European Society of Cardiology/European Respiratory Society guidelines recommend routine annual screening for PAH in SSc and CTDs with SSc features. As CTDs can be associated with a myriad of presentations of pulmonary hypertension, a thorough evaluation to include a right heart catheterization to clearly delineate the hemodynamic profile is essential in developing an appropriate treatment plan. Treatment strategies will depend on the predominant phenotype of pulmonary vasculopathy. In general, management approach to CTD-PAH mirrors that of idiopathic PAH. Despite this, outcomes of CTD-PAH are inferior to those of idiopathic PAH, with those of SSc-PAH being particularly poor. Reasons for this may include extrapulmonary manifestations of CTDs, including renal disease and gastrointestinal involvement, concurrent interstitial lung disease, and differences in the innate response of the right ventricle to increased pulmonary vascular resistance. Early referral for lung transplant evaluation of patients with CTD-PAH, particularly SSc-PAH, is recommended. It is hoped that in the near future, additional therapies may be added to the armamentarium of effective treatments for CTD-PAH. Ultimately, a better understanding of the pathogenesis of CTD-PAH will be required to develop targeted therapies for this morbid condition.

Emerging biologics for the treatment of pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a rare pulmonary vascular disorder, wherein mean systemic arterial pressure (mPAP) becomes abnormally high because of aberrant changes in various proliferative and inflammatory signalling pathways of pulmonary arterial cells. Currently used anti-PAH drugs chiefly target the vasodilatory and vasoconstrictive pathways. However, an imbalance between bone morphogenetic protein receptor type II (BMPRII) and transforming growth factor beta (TGF-β) pathways is also implicated in PAH predisposition and pathogenesis. Compared to currently used PAH drugs, various biologics have shown promise as PAH therapeutics that elicit their therapeutic actions akin to endogenous proteins. Biologics that have thus far been explored as PAH therapeutics include monoclonal antibodies, recombinant proteins, engineered cells, and nucleic acids. Because of their similarity with naturally occurring proteins and high binding affinity, biologics are more potent and effective and produce fewer side effects when compared with small molecule drugs. However, biologics also suffer from the limitations of producing immunogenic adverse effects. This review describes various emerging and promising biologics targeting the proliferative/apoptotic and vasodilatory pathways involved in PAH pathogenesis. Here, we have discussed sotatercept, a TGF-β ligand trap, which is reported to reverse vascular remodelling and reduce PVR with an improved 6-minute walk distance (6-MWDT). We also elaborated on other biologics including BMP9 ligand and anti-gremlin1 antibody, anti-OPG antibody, and getagozumab monoclonal antibody and cell-based therapies. Overall, recent literature suggests that biologics hold excellent promise as a safe and effective alternative to currently used PAH therapeutics.

Independent Predictors of Mortality in Systemic Sclerosis-Associated Pulmonary Arterial Hypertension: A Systematic Review and Meta-Analysis

The aim of this study is to determine the predictors of mortality in patients with systemic sclerosis-induced pulmonary arterial hypertension (SSc-PAH). This systematic review and meta-analysis were carried out according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) Statement guidelines. We searched the PubMed, EMBASE, and Web of Science databases from January 2010 to April 2023 using the following keywords: "systemic sclerosis," "pulmonary arterial hypertension," "death," and "predictors," along with medical subject headings (MeSH), to identify relevant studies. A total of eight studies with a total of 530 patients were included in the present systematic review and meta-analysis. The pooled one-year, three-year, and five-year survival was 90% (95% CI: 86-93%), 66% (95% CI: 59-72%), and 44% (95% CI: 23-65%), respectively. Factors associated with mortality in SSc-PAH included age (p-value: 0.02), male gender (p-value: 0.008), pericardial effusion (p-value: 0.003), cardiac index (p-value: 0.0001), six-minute walking distance (p-value: 0.04), pulmonary arterial pressure (PAP) (p-value: 0.01), and New York Heart Association (NYHA) classification (p-value: 0.0002). The findings of this study have important clinical implications. Assessing and managing the identified predictors, such as age, gender, pericardial effusion, PAP, cardiac index, and NYHA class, could help identify individuals at higher risk of mortality and guide treatment strategies.

Economic burden of illness among patients with pulmonary arterial hypertension (PAH) associated with connective tissue disorders (CTD)

Pulmonary arterial hypertension (PAH) is commonly associated with connective tissue disorders (CTDs). This study provides a contemporary assessment of the economic burden of CTD + PAH and PAH in the United States. Eligible adult patients identified from Optum's deidentified Clinformatics® Data Mart Database (10/01/2015-09/30/2021) were classified into mutually exclusive cohorts based on recorded diagnoses: (1) CTD + PAH, (2) PAH, (3) CTD, (4) control without CTD/PAH. The index date was a randomly selected diagnosis date for PAH (CTD + PAH, PAH cohorts) or CTD (CTD cohort), or a random date (control cohort). Entropy balancing was used to balance characteristics across cohorts. Healthcare costs and healthcare resource utilization (HRU) per patient per month (PPPM) were assessed for ≤12 months postindex and compared among balanced cohorts. A total of 552,900 patients were included (CTD + PAH: n = 1876; PAH: n = 8177; CTD: n = 209,156; control: n = 333,691). Average total all-cause costs were higher for CTD + PAH than PAH cohort ($16,854 vs. $15,686 PPPM; p = 0.02); both cohorts incurred higher costs than CTD and control cohorts ($4476 and $2170 PPPM; all p < 0.001). Average HRU PPPM was similar between CTD + PAH and PAH cohorts (inpatient stay: 0.15 vs. 0.15, outpatient visits: 4.23 vs. 4.11; all p > 0.05), while CTD and control cohorts incurred less HRU (inpatient stay: 0.07 and 0.03, outpatient visits: 2.67 and 1.69; all p < 0.001). CTD + PAH and PAH are associated with a substantial economic burden. The incremental burden attributable to PAH versus the general population and patients with CTD without PAH highlights significant unmet needs among PAH patients.

Serum Biomarkers in Connective Tissue Disease-Associated Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a life-threatening complication of connective tissue diseases (CTDs) characterised by increased pulmonary arterial pressure and pulmonary vascular resistance. CTD-PAH is the result of a complex interplay among endothelial dysfunction and vascular remodelling, autoimmunity and inflammatory changes, ultimately leading to right heart dysfunction and failure. Due to the non-specific nature of the early symptoms and the lack of consensus on screening strategies-except for systemic sclerosis, with a yearly transthoracic echocardiography as recommended-CTD-PAH is often diagnosed at an advanced stage, when the pulmonary vessels are irreversibly damaged. According to the current guidelines, right heart catheterisation is the gold standard for the diagnosis of PAH; however, this technique is invasive, and may not be available in non-referral centres. Hence, there is a need for non-invasive tools to improve the early diagnosis and disease monitoring of CTD-PAH. Novel serum biomarkers may be an effective solution to this issue, as their detection is non-invasive, has a low cost and is reproducible. Our review aims to describe some of the most promising circulating biomarkers of CTD-PAH, classified according to their role in the pathophysiology of the disease.

CTLA-4 Expression Is a Promising Biomarker of Idiopathic Pulmonary Arterial Hypertension and Allows Differentiation of the Type of Pulmonary Hypertension

Pulmonary arterial hypertension (PAH) is an increasingly frequently diagnosed disease, the molecular mechanisms of which have not been thoroughly investigated. The aim of our study was to investigate subpopulations of lymphocytes to better understand their role in the molecular pathomechanisms of various types of PAH and to find a suitable biomarker that could be useful in the differential diagnosis of PAH. Using flow cytometry, we measured the frequencies of lymphocyte subpopulations CD4+CTLA-4+, CD8+ CTLA-4+ and CD19+ CTLA-4+ in patients with different types of PAH, namely pulmonary arterial hypertension associated with congenital heart disease (CHD-PAH), pulmonary arterial hypertension associated with connective tissue disorders (CTD-PAH), chronic thromboembolic pulmonary hypertension (CTEPH) and idiopathic pulmonary arterial hypertension (iPAH), and in an age- and sex-matched control group in relation to selected clinical parameters. Patients in the iPAH group had the significantly highest percentage of CD4+CTLA-4+ T lymphocytes among all PAH groups, as compared to those in the control group (p < 0.001), patients with CTEPH (p < 0.001), CTD-PAH (p < 0.001) and CHD-PAH (p < 0.01). In iPAH patients, the percentages of CD4+CTLA-4+ T cells correlated strongly positively with the severity of heart failure New York Heart Association (NYHA) Functional Classification (r = 0.7077, p < 0.001). Moreover, the percentage of B CD19+CTLA-4+ cells strongly positively correlated with the concentration of NT-proBNP (r = 0.8498, p < 0.001). We have shown that statistically significantly higher percentages of CD4+CTLA-4+ (p ≤ 0.01) and CD8+ CTLA-4+ (p ≤ 0.001) T cells, measured at the time of iPAH diagnosis, were found in patients who died within 5 years of the diagnosis, which allows us to consider both of the above lymphocyte subpopulations as a negative prognostic/predictive factor in iPAH. CTLA-4 may be a promising biomarker of noninvasive detection of iPAH, but its role in planning the treatment strategy of PAH remains unclear. Further studies on T and B lymphocyte subsets are needed in different types of PAH to ascertain the relationships that exist between them and the disease.

Diversity of hemodynamic types in connective tissue disease associated pulmonary hypertension: more than a subgroup of pulmonary arterial hypertension

Objective

Connective tissue disease associated pulmonary hypertension (CTD-PH) is classified as a subgroup of WHO group 1 PH, also called pulmonary arterial hypertension (PAH). However, not all CTD-PH fit hemodynamic definition of PAH. This study investigates the diversity of hemodynamic types of CTD-PH, their differences in clinical characteristics and outcomes.

Method

We performed a retrospective cohort study. CTD-PH patients were enrolled and divided into WHO group1 PH, WHO group 2 PH and hyperdynamic PH (mPAP > 20 mmHg, PVR < 3WU, PAWP < 15 mmHg) according to hemodynamics obtained by right heart catheterization. Patients with severe lung diseases, heart failure with reduced ejection fraction, pulmonary embolism, and hepatic cirrhosis were excluded. Baseline characteristics, autoantibodies, cardiac function, echocardiogram parameters, hemodynamics and survival rates were compared.

Result

A total of 202 CTD-PH patients were included, 138 in WHO group 1 PH, 33 in WHO group 2 PH and 31 in hyperdynamic PH. We found hyperdynamic PH is less severe, presenting lower NT-proBNP level, better WHO function class, lower mPAP and PVR, higher cardiac output, and less cardiac remodeling. Incidence of anti-RNP was significantly lower in patients with elevated PAWP. Short-term survival was worse in WHO group 2 PH, yet 5-year survival rates didn’t differ between groups.

Conclusion

Considering diversity in hemodynamic types, CTD-PH is more than a subgroup of PAH. Different types of CTD-PH present different clinical phenotypes and outcome. Phenotyping PH in CTD-PH patients is important.

Thoracic Involvement in Systemic Autoimmune Rheumatic Diseases: Pathogenesis and Management

Thoracic involvement is one of the main determinants of morbidity and mortality in patients with autoimmune rheumatic diseases (ARDs), with different prevalence and manifestations according to the underlying disease. Interstitial lung disease (ILD) is the most common pulmonary complication, particularly in patients with systemic sclerosis (SSc), idiopathic inflammatory myopathies (IIMs) and rheumatoid arthritis (RA). Other thoracic manifestations include pulmonary arterial hypertension (PAH), mostly in patients with SSc, airway disease, mainly in RA, and pleural involvement, which is common in systemic lupus erythematosus and RA, but rare in other ARDs.In this review, we summarize and critically discuss the current knowledge on thoracic involvement in ARDs, with emphasis on disease pathogenesis and management. Immunosuppression is the mainstay of therapy, particularly for ARDs-ILD, but it should be reserved to patients with clinically significant disease or at risk of progressive disease. Therefore, a thorough, multidisciplinary assessment to determine disease activity and degree of impairment is required to optimize patient management. Nevertheless, the management of thoracic involvement-particularly ILD-is challenging due to the heterogeneity of disease pathogenesis, the variety of patterns of interstitial pneumonia and the paucity of randomized controlled clinical trials of pharmacological intervention. Further studies are needed to better understand the pathogenesis of these conditions, which in turn is instrumental to the development of more efficacious therapies.

The Challenge of Diagnosing and Managing Pulmonary Arterial Hypertension in Systemic Sclerosis with Interstitial Lung Disease

Pulmonary hypertension (PH) in patients with Systemic Sclerosis (SSc) may stem from a variety of underlying causes, thus making a correct diagnosis and management difficult. The main challenges lie in the distinction between pulmonary arterial hypertension (PAH, group 1) and PH due to interstitial lung disease (PH-ILD, group 3) in patients with concomitant lung fibrosis — a very common occurrence in SSc. A consensus among experts remains elusive. Some studies have suggested that among SSc patients with PH, those with an ILD extension > 20% at high-resolution computed tomography (HRCT) should be considered as affected by PH-ILD, whereas other Authors have found that a wide proportion of these patients exhibit features of both PAH and group 3 PH-ILD. We report the case of a 46-year-old male SSc patient with a stable and extensive ILD (>20%) who developed a histologically documented pulmonary vasculopathy typical of PAH and received PAH-specific treatment as bridge to transplant. Moreover, we documented PH disease course by right heart catheterization (RHC), with and without specific vasodilator therapies, which are essential in PAH but not indicated and/or harmful in PH-ILD.

Immunosuppressive therapy in patients with connective tissue disease-associated pulmonary arterial hypertension: A systematic review

OBJECTIVES

It is currently accepted that inflammation plays an important role in the pathogenesis of connective tissue disease-associated pulmonary arterial hypertension (CTD-PAH). However, the efficacy of immunosuppressive therapy remains anecdotal. The objective of this systematic review was to evaluate the efficacy of immunosuppressive therapy in patients with CTD-PAH and to further assess whether response differs between CTD subtypes and clinical features.

METHODS

We systematically searched studies reporting the treatment response of immunosuppressants and biological agents in CTD-PAH from PUBMED, EMBASE, the Cochrane Library, and Scopus. Studies had to report treatment regime and response criteria. The risk of bias was assessed using the Newcastle-Ottawa scale.

RESULTS

Seven independent cohorts, 1 trial, and 1 case-series encompassing 439 patients with CTD-PAH were included. Patients were divided into 2 groups according to the therapeutic regimen. There were 146 patients in the immunosuppressants group with better heart function at baseline and 52.1% (76/146) of them were responders. There were 236 patients treated with immunosuppressants combined with PAH-specific therapy who showed more severity at baseline and 41.1% (97/236) of them were responders. Among different CTD subtypes, patients with systemic lupus erythematosus-associated PAH (SLE-PAH) showed a better response to immunosuppressants (response rate 48.1%). What is more, 1 randomized controlled trial showed the potential therapeutic value of rituximab (n = 57) in CTD-PAH patients.

CONCLUSIONS

Current studies support the use of immunosuppressive therapy in CTD-PAH, especially in SLE-PAH. Further studies on biological agents and the therapeutic effect of different immunosuppressants are still needed.

Altered Cellular Immunity and Differentially Expressed Immune-Related Genes in Patients With Systemic Sclerosis-Associated Pulmonary Arterial Hypertension

Systemic sclerosis (SSc) is the most common connective tissue disease causing pulmonary hypertension (PAH). However, the cause and potential immune molecular events associated with PAH are still unclear. Therefore, it is particularly essential to analyze the changes in SSc-PAH–related immune cells and their immune-related genes. Three microarray datasets (GSE22356, GSE33463, and GSE19617) were obtained by the Gene Expression Omnibus (GEO). Compared with SSc, we found neutrophils have a statistically higher abundance, while T-cell CD4 naive and T-cell CD4 memory resting have a statistically lower abundance in peripheral blood mononuclear cells (PBMCs). Moreover, the results of Gene Set Enrichment Analysis (GSEA) showed there is a differential enrichment of multiple pathways between SSc and SSc-PAH. By combining differentiated expressed genes (DEGs) and immune-related genes (IRGs), fifteen IRGs were selected. In addition, we also analyzed the first five rich Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways and the most abundant Gene Ontology (GO)-molecular functional terms. Furthermore, interleukin-7 receptor (IL-7R), tyrosine–protein kinase (LCK), histone deacetylase 1 (HDAC1), and epidermal growth factor receptor (EGFR) genes were identified as hub genes via protein–protein interaction (PPI) network analysis. The Comparative Toxic Genomics Database (CTD) analysis result showed that LCK, HDAC1, and EGFR have a higher score with SSc. Coexpression network analysis confirmed that IL-7R, LCK, and HDAC1 are key genes related to immune regulation in SSc without PAH and are involved in T-cell immune regulation. Subsequently, using GSE22356 and GSE33463 as the test sets and GSE19617 as the verification set, it was verified that the mRNA expression levels of the three central genes of SSc-PAH were significantly lower than those of the SSc without PAH samples. Consistent with previous predictions, the expressions of IL-7R, LCK, and HDAC1 are positively correlated with the numbers of T-cell CD4 naive and T-cell CD4 memory, while the expressions of IL-7R and LCK are negatively correlated with the numbers of neutrophils in the peripheral blood. Therefore, this evidence may suggest that these three immune-related genes: IL-7R, LCK, and HDAC1, may be highly related to the immunological changes in SSc-PAH. These three molecules can reduce T cells in SSc-PAH PBMCs through the regulation of T-cell activation, which suggests that these three molecules may be involved in the development of SSc-PAH. Meanwhile, the low expression of IL-7R, LCK, and HDAC1 detected in the peripheral blood of SSc may indicate the possibility of PAH and hopefully become a biomarker for the early detection of SSc-PAH. Finally, 49 target miRNAs of 3 specifically expressed hub genes were obtained, and 49 mRNA–miRNA pairs were identified, which provided directions for our further research.

Right Ventricle to Pulmonary Artery Coupling Predicts the Risk Stratification in Patients With Systemic Sclerosis-Associated Pulmonary Arterial Hypertension

Background

Pulmonary arterial hypertension (PAH) is a serious complication of systemic sclerosis (SSc). PAH has high mortality, and risk assessment is critical for proper management. Whether the right ventricle to pulmonary artery (RV-PA) coupling accurately assesses risk status and predicts prognosis in patients with SSc-associated PAH has not been investigated.

Methods

Between March 2010 and July 2018, 60 consecutive patients with SSc-associated PAH diagnosed by right heart catheterization were enrolled prospectively, and the mean follow-up period was 52.9 ± 27.0 months. The RV-PA coupling was assessed by the ratio of tricuspid annular plane systolic excursion (TAPSE) and pulmonary artery systolic pressure (PASP) which was obtained by transthoracic echocardiography. The simplified risk stratification strategy was applied to assess the risk level of participants, and the endpoint was a composite of all-cause death and clinical worsening.

Results

The receiver operating characteristic (ROC) curve of the ability to determine high-risk patients identified the optimal cut-off value of the TAPSE/PASP ratio as 0.194 mm/mmHg, and the ratio appeared to be a reliable indicator in the stratification of patients with high risk (area under the curve = 0.878, ROC P-value = 0.003), which showed the highest positive likelihood ratio (LR) (5.4) and the lowest negative LR (0) among a series of echocardiographic parameters. The TAPSE/PASP ratio was an independent predictive factor (HR = 0.01, 95% CI: 0.00–0.77, P = 0.037) for the composite endpoint, and patients with a TAPSE/PASP ratio >0.194 had a better overall survival for both the composite endpoint (log-rank χ² = 5.961, P = 0.015) and all-cause mortality (log-rank χ² = 8.004, P = 0.005) compared to the patients with a TAPSE/PASP ≤ 0.194.

Conclusion

RV-PA coupling assessed by the TAPSE/PASP ratio provides added value as a straightforward and non-invasive approach for predicting risk stratification of patients with SSc-associated PAH. Meanwhile, a lower TAPSE/PASP ratio identified a subgroup with worse prognosis.

VPO1/HOCl/ERK pathway mediates the right ventricular remodeling in rats with hypoxic pulmonary hypertension

Right ventricular (RV) remodeling is a major feature of pulmonary arterial hypertension (PAH). Vascular peroxidase 1 (VPO1) is reported to participate in the process of PAH. This study aims to explore whether VPO1 contributes to hypoxia-induced cardiac hypertrophy and the underlying mechanisms. SD rats were exposure to continuous hypoxia (10% O₂) for 3 weeks, which showed RV hypertrophy (increases in the ratio of RV weight to tibia length, cardiac cell size and hypertrophic markers), concomitant with upregulation of VPO1, elevation in hypochlorous acid (HOCl) production and ERK phosphorylation. In hypoxia (3% O₂)-induced hypertrophic H9c2 cells, similar characteristics of cardiac hypertrophy to that of hypoxia-treated rats were observed. Administration of VPO1 siRNA or NaHS (the HOCl inhibitor) suppressed HOCl production, ERK phosphorylation, and cardiac hypertrophy. Replacement of hypoxia with NaClO (exogenous HOCl) could also induce cardiac cell hypertrophy and activate ERK signaling pathway. In addition, hypoxia-induced cardiac hypertrophy could be blocked by PD98059 (the ERK-specific inhibitor). Based on these observations, we conclude that VPO1 promotes RV remodeling in PAH rats through catalyzing HOCl production, leading to the activation of ERK signaling. Thus, VPO1 may have the potential as a therapeutic target for PAH.

Text Mining-Based Drug Discovery for Connective Tissue Disease–Associated Pulmonary Arterial Hypertension

Background: The current medical treatments for connective tissue disease–associated pulmonary arterial hypertension (CTD-PAH) do not show favorable efficiency for all patients, and identification of novel drugs is desired.

Methods: Text mining was performed to obtain CTD- and PAH-related gene sets, and the intersection of the two gene sets was analyzed for functional enrichment through DAVID. The protein–protein interaction network of the overlapping genes and the significant gene modules were determined using STRING. The enriched candidate genes were further analyzed by Drug Gene Interaction database to identify drugs with potential therapeutic effects on CTD-PAH.

Results: Based on text mining analysis, 179 genes related to CTD and PAH were identified. Through enrichment analysis of the genes, 20 genes representing six pathways were obtained. To further narrow the scope of potential existing drugs, we selected targeted drugs with a Query Score ≥5 and Interaction Score ≥1. Finally, 13 drugs targeting the six genes were selected as candidate drugs, which were divided into four drug–gene interaction types, and 12 of them had initial drug indications approved by the FDA. The potential gene targets of the drugs on this list are IL-6 (one drug) and IL-1β (two drugs), MMP9 (one drug), VEGFA (three drugs), TGFB1 (one drug), and EGFR (five drugs). These drugs might be used to treat CTD-PAH.

Conclusion: We identified 13 drugs targeting six genes that may have potential therapeutic effects on CTD-PAH.

Use of small pulmonary vascular alterations to identify different types of pulmonary hypertension: a quantitative computed tomography analysis

BACKGROUND

The morphological alterations of small pulmonary vessels measured by computed tomography (CT) is increasingly used in evaluation of suspected pulmonary hypertension (PH).

OBJECTIVE

To investigate the significance alterations of quantitative assessment of small pulmonary vessels on chest CT in distinguishing different types of PH and their severity.

METHODS

We retrospectively analyzed a dataset of 120 healthy controls (HCs) and 91 PH patients, including 34 patients with connective tissue diseases-related PH (CTD-PH), 26 patients with idiopathic pulmonary arterial hypertension (iPAH), and 31 patients with chronic obstructive pulmonary disease-related PH (COPD-PH). The CTD-PH patients were divided into mild to moderate PH (CTD-LM-PH) group (n = 17) and severe PH (CTD-S-PH) group (n = 17). A total of 53 CTD patients without PH (CTD-nPH) were enrolled for comparison with the CTD-PH. We measured the cross-sectional area of small pulmonary vessels < 5 mm2 (%CSA <5) and between 5-10 mm2 (%CSA5-10) as a percentage of total lung area among the populations included above and compared %CSA in different types of PH groups and HCs group. The mean pulmonary arterial pressure (mPAP) was measured by right heart catheterization.

RESULTS

The %CSA5-10 of COPD-PH, CTD-PH, and iPAH patients increased (0.21±0.09, 0.49±0.20 and 0.61±0.20, p < 0.02) sequentially, while the %CSA <5 of CTD-PH, iPAH, and COPD-PH patients decreased (0.79±0.65, 0.65±0.38 and 0.52±0.27, p < 0.05) sequentially. The %CSA5-10 was significantly higher in CTD-S-PH patients than CTD-LM-PH patients and CTD-nPH patients (0.51±0.21, 0.31±0.15 and 0.28±0.12, p < 0.01). The %CSA5-10 was positively correlated with mPAP in the CTD-PH group.

CONCLUSIONS

The quantitative parameters %CSA <5 and %CSA5-10 assessed by chest CT are useful for distinguishing different types of PH. In addition, the %CSA5-10 can provide information for identification of CTD-PH severity.

Evaluation of pulmonary arterial pressure in patients with connective tissue disease-associated pulmonary arterial hypertension by myocardial perfusion imaging

BACKGROUND

Pulmonary arterial hypertension (PAH) is a complex and severe complication of connective tissue disease (CTD). We aimed to evaluate the application value of myocardial perfusion imaging (MPI) in evaluating CTD-associated PAH (CTD-PAH).

METHODS

We retrospectively included 88 patients who were diagnosed with CTD between January 2018 and December 2020 at our hospital. Fifty-eight patients had PAH and were included into the CTD-PAH group. Thirty patients without PAH were included in the control group. All patients received routine physical examination, biochemical tests and cardiac function evaluation, right heart catheterization (RHC), and ^99m Tc-MIBI MPI. PAH patients were divided into the mild, moderate, and severe PAH group according to their mean pulmonary artery pressures by RHC. Pearson correlation analysis was used to calculate the correlation between the right ventricle target/background (T/B) and right ventricle stroke volume (RV-SV), total pulmonary resistance (TPR), pulmonary vascular resistance (PVR), mean pulmonary arterial pressure (mPAP), 6-minute walk distance (6-MWD), and N-terminal B-type natriuretic peptide (NT-proBNP). The ROC curves of T/B and pulmonary artery pressure classification were plotted and the sensitivity and specificity of T/B in diagnosing PAH of different severities were analyzed.

RESULTS

The analysis of correlation revealed that T/B correlated negatively with 6-MWD and positively with NT-proBNP and exhibited good positive correlation with mPAP, TPR, and PVR by RHC and negative correlation with RV-SV. T/B was of the most diagnostic value for severe PAH, and its correlation with severe PAH was stronger than that with mild PAH and moderate PAH.

CONCLUSIONS

Target/background is a noninvasive method that can simultaneously evaluate pulmonary arterial pressure and myocardial perfusion of CTD-CHD patients and is particularly of relatively high value for severe PAH patients.

Diagnosis and management of lung involvement in systemic lupus erythematosus and Sjögren's syndrome: a literature review

Lung involvement in systemic lupus erythematosus (SLE) and primary Sjögren's syndrome (pSS) has extensively been outlined with a multiplicity of different manifestations. In SLE, the most frequent finding is pleural effusion, while in pSS, airway disease and parenchymal disorders prevail. In both cases, there is an increased risk of pre-capillary and post-capillary pulmonary arterial hypertension (PAH) and pulmonary venous thromboembolism (VTE). The risk of VTE is in part due to an increased thrombophilic status secondary to systemic inflammation or to the well-established association with antiphospholipid antibody syndrome (APS). The lung can also be the site of an organ-specific complication due to the aberrant pathologic immune-hyperactivation as occurs in the development of lymphoma or amyloidosis in pSS. Respiratory infections are a major issue to be addressed when approaching the differential diagnosis, and their exclusion is required to safely start an immunosuppressive therapy. Treatment strategy is mainly based on glucocorticoids (GCs) and immunosuppressants, with a variable response according to the primary pathologic process. Anticoagulation is recommended in case of VTE and multi-targeted treatment regimens including different drugs are the mainstay for PAH management. Antibiotics and respiratory physiotherapy can be considered relevant complement therapeutic measures. In this article, we reviewed lung manifestations in SLE and pSS with the aim to provide a comprehensive overview of their diagnosis and management to physicians taking care of patients with connective tissue diseases.

Higher Ventricular-Arterial Coupling Derived from Three-Dimensional Echocardiography Is Associated with a Worse Clinical Outcome in Systemic Sclerosis

Primary myocardial involvement is common in systemic sclerosis (SSc). Ventricular-arterial coupling (VAC) reflecting the interplay between ventricular performance and arterial load, is a key determinant of cardiovascular (CV) performance. We aimed to investigate VAC, VAC-derived indices, and the potential association between altered VAC and survival free from death/hospitalization for major adverse CV events (MACE) in scleroderma. Only SSc patients without any anamnestic and echocardiographic evidence of primary myocardial involvement who underwent three-dimensional echocardiography (3DE) were included in this cross-sectional study and compared with healthy matched controls. 3DE was used for noninvasive measurements of end-systolic elastance (Ees), arterial elastance (Ea), VAC (Ea/Ees) and end-diastolic elastance (Eed); the occurrence of death/hospitalization for MACE was recorded during follow-up. Sixty-five SSc patients (54 female; aged 56 ± 14 years) were included. Ees (p = 0.04), Ea (p = 0.04) and Eed (p = 0.01) were higher in patients vs. controls. Thus, VAC was similar in both groups. Ees was lower and VAC was higher in patients with diffuse cutaneous form (dcSSc) vs. patients with limited form (lcSSc) (p = 0.001 and p = 0.02, respectively). Over a median follow-up of 4 years, four patients died for heart failure and 34 were hospitalized for CV events. In patients with VAC > 0.63 the risk of MACE was higher (HR 2.5; 95% CI 1.13-5.7; p = 0.01) and survival free from death/hospitalization was lower (p = 0.005) than in those with VAC < 0.63. Our study suggests that VAC may be impaired in SSc patients without signs and symptoms of primary myocardial involvement. Moreover, VAC appears to have a prognostic role in SSc.

Clinical characteristics and survival of patients with three major connective tissue diseases associated with pulmonary hypertension: A study from China

The present cross-sectional study investigated the clinical characteristics and survival of patients with three types of connective tissue disease associated with pulmonary hypertension (CTD-PH) diagnosed early by echocardiography. A total of 218 patients with CTD-PH were included in the present study. Patients with the three major types of CTD, namely systemic lupus erythematosus (SLE), systemic sclerosis (SSc) and primary Sjögren's syndrome (pSS), were included. PH was diagnosed based on pulmonary arterial systolic pressure >35 mmHg, as measured by Doppler echocardiography. Demographic data, clinical features, laboratory results and echocardiographic parameters were collected and analyzed. The Kaplan-Meier method was used to calculate survival rates. Multivariate analysis was used to identify independent factors affecting mortality. Compared with patients with CTD with pSS (6.5%) or SLE (3.8%), those with SSc had a higher prevalance of PH (12.9%). Patients with SSc-PH had the highest rate of lung involvement (81.2%) and 42.2% of patients were classified as World Health Organization-function class III/IV at the time of diagnosis with PH. The overall survival rate among patients with CTD-PH at 1, 3 and 5 years was 81.4, 72.4 and 56.9%, respectively. Patients with SLE-PH appeared to have the most favorable prognosis and patients with SSc-PH had the poorest relative outcomes. Multivariate analysis revealed that age ≥50 years was the only independent risk factor for mortality. In conclusion, among the patients with CTDs investigated, the prevalence of PH was highest among those with SSc. Patients with SSc-PH had the highest prevalence of pulmonary involvement, the lowest survival rate and the worst prognosis.

[The place of riociguat in the treatment of patients with pulmonary arterial hypertension associated with systemic connective tissue diseases]

Pulmonary hypertension (PH) can develop in different systemic autoimmune rheumatic diseases (SARD), such as systemic scleroderma (SSD), systemic lupus erythematosus, rheumatoid arthritis, and mixed connective tissue disease In most cases, patients with SARD develop WHO group I PH (pulmonary arterial hypertension associated with systemic connective tissue diseases, PAH-SCTD). General prevalence of this pathology reaches 15 cases per million adults. Most cases of PAH-SCTD are induced by SSD. Survival of PAH-SCTD patients is generally lower than survival of patients with other forms of LAH. Treatment of any SARD, including in LAH, implies a complex approach using glucocorticoids, disease-modifying anti-rheumatic drugs (cyclophosphamide, methotrexate, azathioprine, and others), and genetically engineered biologics. Specific targeted therapy is indicated for most patients with PAH-SCTD. The representative of a new class (soluble guanylate cyclase (sGC) stimulators), riociguat, has been approved for the treatment of PAH. This drug has a unique double mechanism of action: (i) sGC sensibilization to endogenous nitric oxide (NO) by stabilizing the NO-sGC bond; and (ii) direct, NO-independent sGC stimulation. For patients with PAH-SCTD, riociguat is the major alternative to phosphodiesterase-5 inhibitors both as monotherapy and combination therapy.

Role of Gas6 and TAM Receptors in the Identification of Cardiopulmonary Involvement in Systemic Sclerosis and Scleroderma Spectrum Disorders

Background

Few biomarkers are available for early identification of pulmonary arterial hypertension (PAH) and interstitial lung disease (ILD) in systemic sclerosis (SS) and scleroderma spectrum disorders (SSD).

Aims

To evaluate Gas6, sAxl, and sMer as biomarkers for cardiopulmonary complications of SS and SSD.

Methods

In a cross-sectional observational study, we recruited 125 consecutive patients, affected by SS and SSD and referred to a tertiary-level pulmonary hypertension outpatient clinic. All patients underwent a comprehensive evaluation for identification of PAH and ILD. Gas6, sMer, and sAxl concentrations were measured with ELISA protocols, and concentrations were compared according to PAH or ILD.

Results

Nineteen subjects had pulmonary hypertension (PH) (14 PAH), and 39 had ILD (6 severe). Plasma sMer was increased in PAH (18.6 ng/ml IQR [11.7-20.3]) with respect to the absence (12.4 [8.0-15.8]) or other form of pulmonary hypertension (9.6 [7.4-12.5]; K–W variance p < 0.04). Conversely, Gas6 and sAxl levels were slightly increased in mild ILD (25.8 ng/ml [19.5-32.1] and 24.6 [20.1-32.5]) and reduced in severe ILD (16.6 [15.0-22.1] and 15.5 [14.9-22.4]) in comparison to no evidence of ILD (23.4 [18.8-28.1] and 21.6 [18.1-28.4]; K–W, p ≤ 0.05). Plasma sMer ≥ 19 ng/ml has 50% sensitivity and 92% specificity in PAH identification (area under the ROC curve (AUC) 0.697, p < 0.03). Values of Gas6 ≤ 24.5 ng/ml and of sAxl ≤ 15.5 ng/ml have 100% and 67% sensitivity and 47% and 86% specificity, respectively, in identifying severe ILD (Gas6 AUC 0.787, p < 0.001; sAxl AUC 0.705, p < 0.05).

Conclusions

The assay of Gas6 sAxl and sMer may be useful to help in the identification of PAH and ILD in SS and SSD patients. The Gas6/TAM system seems to be relevant in cardiopulmonary complications of SS and SSD and merits further investigations.

Squamous cell carcinoma antigen-IgM (SCCA-IgM) is associated with interstitial lung disease in systemic sclerosis

OBJECTIVE

Interstitial lung disease (ILD) is the major determinant of prognosis in patients with systemic sclerosis (SSc). Squamous Cell Carcinoma Antigen (SCCA1) is a serin protease inhibitor which plays a pivotal role in inflammation and fibrosis. SCCA1 is overexpressed in pulmonary tissue of patients with idiopathic pulmonary fibrosis and can be detectable in serum as circulating immune complex bound to IgM (SCCA-IgM). We aimed to investigate the association between SCCA-IgM and clinical features of patients with SSc.

METHODS

Ninety-seven patients with SSc (ACR/EULAR criteria) were consecutively enrolled in the study. Clinical and serological variables and organ involvement were recorded. Pulmonary involvement was investigated by high-resolution CT (HRCT) and respiratory function tests. SCCA-IgM serum levels were measured by a validated ELISA assay (Hepa-IC, Xeptagen, Venice, Italy). We set the cut-off value for serum levels of SCCA-IgM >200 AU/ml, calculated as mean+3 standard deviations in 100 healthy subjects.

RESULTS

Forty-one (42.3%) patients were affected with ILD. SCCA-IgM values were significantly higher in patients with ILD than in those without: 218 (80-402) vs. 87.5 (59-150) AU/mL, P=0.003. Patients with positive SCCA-IgM had more frequently ILD (69.7% vs. 28.1%, P≤0.0001) and a lower total lung capacity (TLC) (P=0.024) compared with negative ones. No differences were found in any other clinical and serological features. At multivariate analysis, SCCA-IgM was found to be associated with ILD diagnosis (OR 10.6, IC 2.9-38.4, P=0.001).

CONCLUSION

SCCA-IgM is associated with interstitial lung disease in scleroderma patients and might be used in the assessment of SSc-ILD.