Reduced diffusing capacity for carbon monoxide predicts borderline pulmonary arterial pressure in patients with systemic sclerosis

The chest CT signs for pulmonary veno-occlusive disease correlate with pulmonary haemodynamics in systemic sclerosis

OBJECTIVES

Pulmonary arterial hypertension associated with systemic sclerosis (PAH-SSc) sometimes accompanies pulmonary veno-occlusive disease (PVOD). We aimed to reveal the relationship between clinical signs of PVOD and severity of pulmonary vasculopathy in SSc.

METHODS

This study included 52 consecutive SSc patients who had pulmonary haemodynamic abnormalities [mean pulmonary arterial pressure (mPAP) >20 mmHg, pulmonary vascular resistance >2 WU or pulmonary artery wedge pressure (PAWP) >15 mmHg]. A chest CT scan was evaluated in all patients. Patients were divided into two groups, the 0-1 group and the 2-3 group, according to the number of chest CT signs for PVOD, including mediastinal lymph node enlargement, thickened interlobular septal wall and ground glass opacity. Pulmonary haemodynamics, echocardiography and MRI-based cardiac function, pulmonary function and serum biomarkers were compared between the two groups.

RESULTS

Mediastinal lymph node enlargement, thickened interlobular septal wall and ground glass opacity were observed in 11 (21%), 32 (62%) and 11 (21%) patients, respectively. The 2-3 group (n = 15) had higher mPAP (P = 0.02) but lower diffusing capacity of carbon monoxide (DLCO)/alveolar volume (P = 0.02) compared with the 0-1 group (n = 37). Other parameters, including PAWP, cardiac output, left ventricular ejection fraction, left atrial diameter, forced vital capacity, brain natriuretic peptide and Krebs von den Lunge-6 were not different between the two groups.

CONCLUSIONS

The CT signs for PVOD had a positive correlation with mPAP but a negative correlation with DLCO in SSc patients, indicating that PAH-SSc may reflect a spectrum of pulmonary vascular disease that ranges from the pulmonary artery to the vein.

Systemic sclerosis

Systemic sclerosis, also known as scleroderma, is a rare and complex autoimmune connective-tissue disease. Once considered an untreatable and unpredictable condition, research advancements have improved our understanding of its disease pathogenesis and clinical phenotypes and expanded our treatment armamentarium. Early and accurate diagnosis is essential, while ongoing efforts to risk stratify patients have a central role in predicting both organ involvement and disease progression. A holistic approach is required when choosing the optimal therapeutic strategy, balancing the side-effect profile with efficacy and tailoring the treatment according to the goals of care of the patient. This Seminar reviews the multiple clinical dimensions of systemic sclerosis, beginning at a precursor very early stage of disease, with a focus on timely early detection of organ involvement. This Seminar also summarises management considerations according to the pathological hallmarks of systemic sclerosis (eg, inflammation, fibrosis, and vasculopathy) and highlights unmet needs and opportunities for future research and discovery.

The Role of Anti-U1 RNP Antibody in Connective Tissue Disease-Associated Pulmonary Arterial Hypertension: A Systematic Review and Meta-Analysis

Connective tissue disease (CTD) patients may suffer from pulmonary arterial hypertension (PAH), a serious complication, and anti-U1 ribonucleoprotein (RNP) antibodies can be used as a potential indicator for the development and prognosis of CTD-associated PAH (CTD-PAH). However, there are still some controversies; thus, a systematic review and meta-analysis were performed. We searched PubMed, Embase, Cochrane Library, and Scopus for eligible studies and assessed their quality using Newcastle−Ottawa scales or Agency for Healthcare Research and Quality indicators according to the type of research. Odds ratio (OR) was adopted as a measure of effect in risk factor analysis, and hazard ratio (HR) was adopted for prognostic factor analysis. Publication bias was evaluated using the Egger’s test. Thirteen studies were finally included. Anti-U1 RNP antibody was proved as a risk factor for PAH among CTD patients (OR = 5.30, 95%CI 2.96−9.48, p < 0.05) and a protective factor against mortality among CTD-PAH patients (HR = 0.55, 95%CI 0.36−0.83, p < 0.05). CTD patients with positive anti-U1 RNP antibodies are at high risk for PAH, so routine screening examinations, including echocardiography, are recommended. Additionally, anti-U1 RNP positivity has been linked to decreased mortality in patients with CTD-PAH.

Diagnostic and prognostic markers and treatment of connective tissue disease-associated pulmonary arterial hypertension: current recommendations and recent advances

INTRODUCTION

Pulmonary arterial hypertension (PAH), also referred to as group 1 pulmonary hypertension, occurs either primarily or in association with other diseases such as connective tissue diseases (CTD). Of CTD, systemic sclerosis (SSc), systemic lupus erythematosus and mixed connective tissue disease are commonly accompanied with PAH. It is of note that SSc-PAH is associated with distinctive histopathology, an unfavorable outcome, and a blunted responsiveness to modern PAH therapies.

AREAS COVERED

The data in articles published until May 2020 in peer-reviewed journals, covered by PubMed databank, are discussed. The current review introduces recent advances over the past years which have moved our understanding of CTD-PAH forward and discusses what we are currently able to do and what will be necessary in the future to overcome the yet unsatisfactory situation in the management of CTD-PAH, particularly in that of SSc-PAH.

EXPERT OPINION

A multifaceted and integrated approach would be crucial to improve the outcome of patients with SSc-PAH. The authors also propose a possible algorithm to classify and treat SSc patients with suspicion of pulmonary vascular disease.