Project description:Pulmonary arterial hypertension (PAH) is a rare, progressive disease affecting both adults and children. While overall survival has improved in recent years, the need for improved therapeutic approaches remains. Treatments for paediatric PAH have not yet been sufficiently examined, particularly regarding potential toxicities and optimal dosing, and there is a lack of appropriate clinical trial end-points and validated treatment goals that might enable a goal-oriented therapeutic approach. Adult randomised controlled trials in PAH are demonstrating a shift towards more long-term designs, focusing on mortality and morbidity end-points rather than changes in 6-min walking distance. However, such trial designs may not be feasible within the paediatric setting due to challenges such as sufficient recruitment and retention of paediatric patients. Consideration should, therefore, be given towards identifying optimal end-points for the paediatric population, allowing sufficient duration to evaluate efficacy and safety of potential treatments. Herein we consider some of the complexities involved in the management of paediatric PAH, specifically presenting diagnostic challenges as well as reflecting on the lack of evidence currently available to support various therapeutic approaches within the paediatric population.
Project description:Despite many advances in medical therapy for pulmonary arterial hypertension (PAH) over the past 20 years, long-term survival is still poor. Novel therapies which target the underlying pathology of PAH and which could be added to current vasodilatory therapies to halt disease progression and potentially reverse pulmonary vascular remodeling are highly sought after. Given the high attrition rates, substantial costs, and slow pace of new drug development, repositioning of "old" drugs is increasingly becoming an attractive path to identify novel treatment options, especially for a rare disease such as PAH. We here summarize the limitations of current PAH therapy, the general concept of repurposing and repositioning, success stories of approved repositioned drugs in PAH as well as novel repositioned drugs that show promise in preclinical models of pulmonary hypertension (PH) and are currently tested in clinical trials. We furthermore discuss various data-driven as well as experimental approaches currently used to identify repurposed drug candidates and review challenges for the "repositioning community" with regards to funding and patent and regulatory considerations, and to illustrate opportunities for collaborative solutions for drug repositioning relevant to PAH.
Project description:Advances in the diagnosis and management of pulmonary arterial hypertension (PAH) have resulted in significant improvements in outcomes for patients with this devastating and progressive disease. However, because of the non-specific nature of its symptoms, and the low level of suspicion among clinicians, prompt and accurate diagnosis of PAH as a rare disease remains a challenge. This article explains some of the issues that need to be addressed when faced with a patient with suspected PAH and describes how noninvasive and invasive techniques can be used effectively to ensure an accurate diagnosis. The availability of PAH-specific therapy means that once diagnosed, patients have a much greater chance of survival than they would have had in the past. However, despite improved survival, mortality is still high and, therefore, there is still room for improvement. It is currently recommended that patients with an inadequate clinical response to treatment receive sequential combination therapy; however, supportive data are still scarce. Although there is no clear explanation, these findings may be explained by the design and end-points chosen in clinical trials, the changing population of PAH and a need to improve the management strategy in this disease. Indeed, there is a clear need for randomised controlled studies that investigate whether adopting individualised treatment strategies, including upfront combination therapy, could help to optimise long-term management of patients with PAH.
Project description:Systemic sclerosis (SSc) is a chronic, multisystem autoimmune disease characterized by vasculopathy, fibrosis and immune system activation. Pulmonary hypertension and interstitial lung disease account for majority of SSc-related deaths. Diagnosis of SSc-PAH can be challenging due to nonspecific clinical presentation which can lead to delayed diagnosis. Many screening algorithms have been developed to detect SSc-associated pulmonary arterial hypertension (SSc-PAH) in early stages. Currently used PAH-specific medications are largely extrapolated from IPAH studies due to smaller number of patients with SSc-PAH. In this review, we discuss the current state of knowledge in epidemiology and risk factors for development of SSc-PAH, and challenges and potential solutions in the diagnosis, screening and management of SSc-PAH.
Project description:Although multiple gene and protein expression have been extensively profiled in human pulmonary arterial hypertension (PAH), the mechanism for the development and progression of pulmonary hypertension remains elusive. Analysis of the global metabolomic heterogeneity within the pulmonary vascular system leads to a better understanding of disease progression. Using a combination of high-throughput liquid-and-gas-chromatography-based mass spectrometry, we showed unbiased metabolomic profiles of disrupted glycolysis, increased TCA cycle, and fatty acid metabolites with altered oxidation pathways in the severe human PAH lung. The results suggest that PAH has specific metabolic pathways contributing to increased ATP synthesis for the vascular remodeling process in severe pulmonary hypertension. These identified metabolites may serve as potential biomarkers for the diagnosis of severe PAH. By profiling metabolomic alterations of the PAH lung, we reveal new pathogenic mechanisms of PAH in its later stage, which may differ from the earlier stage of PAH, opening an avenue of exploration for therapeutics that target metabolic pathway alterations in the progression of PAH. Global profiles were determined in human lung tissue and compared across 11 normal and 12 severe pulmonary arterial hypertension patients. Using a combination of microarray and high-throughput liquid-and-gas-chromatography-based mass spectrometry, we showed unbiased metabolomic profiles of disrupted glycolysis, increased TCA cycle, and fatty acid metabolites with altered oxidation pathways in the severe human PAH lung.
Project description:Arterial pulmonary hypertension is a rare disease, with little knowledge regarding its etiology, and high mortality. Development of right and later on also left ventricular heart insufficiency, secondary to pulmonary hypertension, is a negative predictive factor. Genetic and molecular processes underlying left heart ventricle remodeling over the course of pulmonary hypertension remain unknown. In particular, there is no knowledge regarding the mechanisms of left heart ventricle atrophy which was completely avoided by researchers until recently.The aim of this study was to assess changes in protein abundance in left and right heart ventricle free wall of rats in monocrotaline model of PAH.
Project description:Systemic sclerosis (SSc) is a rare autoimmune disorder with multi-organ involvement. SSc-associated pulmonary arterial hypertension (SSc-PAH) is one of the leading causes of morbidity and mortality in the SSc population. With advances in our understanding of pulmonary arterial hypertension (PAH) diagnosis and treatment, outcomes for all PAH patients have significantly improved. While SSc-PAH patients have also benefited from these advances, significant challenges remain. Diagnosis of PAH is a challenging endeavor in SSc patients who often have many co-existing pulmonary and cardiac comorbidities. Given the significantly elevated prevalence and lifetime risk of PAH in the SSc population, screening for SSc-PAH is a critically useful strategy. Treatment with pulmonary arterial (PA) vasodilators has resulted in a dramatic improvement in the survival and quality of life of PAH patients. While therapy with PA vasodilators is beneficial in SSc-PAH patients, therapy effects appear to be attenuated when compared to responses in patients with idiopathic PAH (IPAH). This review attempts to chronicle and summarize the advances in our understanding of the optimal screening strategies to identify PAH in patients with SSc. The article also reviews the advances in the therapeutic and risk stratification strategies for SSc-PAH patients.
Project description:Pulmonary arterial hypertension (PAH) is a severe and incurable pulmonary vascular disease. One of the primary origins of PAH is pulmonary endothelial dysfunction leading to vasoconstriction, aberrant angiogenesis and smooth muscle cell proliferation, endothelial-to-mesenchymal transition, thrombosis and inflammation. Our objective was to study the epigenetic variations in pulmonary endothelial cells (PEC) through a specific pattern of DNA methylation. DNA was extracted from cultured PEC from patients with idiopathic PAH (n=11), heritable PAH (n=10) and controls (n=18). ). DNA methylation was assessed using the Illumina HumanMethylation450 Assay. After normalization, samples and probes were clustered according to their methylation profile. Differential clusters were functionally analysed using bioinformatics tools.
Project description:Comparison of miRNA expression between patients with idiopathic and systemic sclerosis PAH and healthy controls and systemic sclerosis without PAH