Pulmonary arterial hypertension (PAH) is a progressive disease characterised by remodelling of small pulmonary arteries leading to an increased pulmonary vascular resistance, right ventricular ...failure and death. Available treatments try to re-establish the equilibrium on three signalling pathways: the prostacyclin, the endothelin (ET)-1 and the nitric oxide. Prostanoids, such as epoprostenol or treprostinil have a vasodilator, antiproliferative and immunomodulatory effect and, despite the administration inconveniences, represent established therapies for severe cases of PAH. Recently oral prostacyclin receptor agonists have shown encouraging results. Many clinical studies targeting the vasoconstrictor ET-1 pathway with receptor antagonists like bosentan and ambrisentan have shown strong results, even more optimism coming from macitentan, the newest drug. Sildenafil and tadalafil, two phosphodiesterase type-5 inhibitors, have shown improved exercise capacity by increasing the nitric oxide level. Riociguat, acting on the same nitric oxide pathway, as a guanylatecyclase activator, has shown promising results in clinical trials and will be available soon. Long-awaited results for tyrosin-kinase inhibitor, imatinib, as an antiproliferative therapy in PAH have been disappointing, due to severe adverse events. In conclusion, although it remains a disease with severe prognosis, the past 20 years have represented a huge progress in terms of treatments for PAH with interesting opportunities for the future.
Although the causal pathomechanisms contributing to remodelling of the pulmonary vascular bed in pulmonary arterial hypertension (PAH) are still unclear, several analogous features with ...carcinogenesis have led to the emergence of the cancer-like concept. The major similarities concern the altered crosstalk between cells from different tissue types, unexplained proliferation and survival of pulmonary smooth muscle and endothelial cells, the metabolic (glycolytic) shifts, and the association with the immune system. However, major differences between PAH and cancer exist, including the absence of invasion and metastasis, as well as the pathogenic genes involved and the degrees of angiogenesis impairment and genetic instability. It is clear that PAH is not a cancer, but this cancer-like concept has opened a new field of investigation and raises the possibility that antiproliferative and/or oncological drugs may exert therapeutic effects not only in cancer, but also in PAH. Such analogies and differences are discussed here.
•First clinical trial of eteplirsen in patients with DMD aged 6 to 48 months.•Safety experience was consistent with the known safety profile of eteplirsen.•Eteplirsen was well tolerated with no ...evidence of kidney toxicity.•Eteplirsen pharmacokinetics was comparable with that of boys older than 4 years.
Eteplirsen is FDA-approved for the treatment of Duchenne muscular dystrophy (DMD) in exon 51 skip-amenable patients. Previous studies in boys > 4 years of age indicate eteplirsen is well tolerated and attenuates pulmonary and ambulatory decline compared with matched natural history cohorts. Here the safety, tolerability and pharmacokinetics of eteplirsen in boys aged 6–48 months is evaluated. In this open-label, multicenter, dose-escalation study (NCT03218995), boys with a confirmed mutation of the DMD gene amenable to exon 51 skipping (Cohort 1: aged 24–48 months, n = 9; Cohort 2: aged 6 to < 24 months, n = 6) received ascending doses (2, 4, 10, 20, 30 mg/kg) of once-weekly eteplirsen intravenously over 10 weeks, continuing at 30 mg/kg up to 96 weeks. Endpoints included safety (primary) and pharmacokinetics (secondary). All 15 participants completed the study. Eteplirsen was well tolerated with no treatment-related discontinuations, deaths or evidence of kidney toxicity. Most treatment-emergent adverse events were mild; most common were pyrexia, cough, nasopharyngitis, vomiting, and diarrhea. Eteplirsen pharmacokinetics were consistent between both cohorts and with previous clinical experience in boys with DMD > 4 years of age. These data support the safety and tolerability of eteplirsen at the approved 30-mg/kg dose in boys as young as 6 months old.
Pulmonary arterial hypertension (PAH) is a rare disorder characterised by progressive obliteration of the pulmonary microvasculature resulting in elevated pulmonary vascular resistance and premature ...death. According to the current classification PAH can be associated with exposure to certain drugs or toxins, particularly to appetite suppressant intake drugs, such as aminorex, fenfluramine derivatives and benfluorex. These drugs have been confirmed to be risk factors for PAH and were withdrawn from the market. The supposed mechanism is an increase in serotonin levels, which was demonstrated to act as a growth factor for the pulmonary artery smooth muscle cells. Amphetamines, phentermine and mazindol were less frequently used, but are considered possible risk factors, for PAH. Dasatinib, dual Src/Abl kinase inhibitor, used in the treatment of chronic myelogenous leukaemia was associated with cases of severe PAH, potentially in part reversible after dasatinib withdrawal. Recently, several studies have raised the issue of potential endothelial dysfunction that could be induced by interferon, and a few cases of PAH have been reported with interferon therapy. PAH remains a rare complication of these drugs, suggesting possible individual susceptibility, and further studies are needed to identify patients at risk of drug-induced PAH.
Klippel-Trenaunay syndrome (KTS) is a congenital disorder characterized by cutaneous capillary malformations, soft tissue and bone hypertrophy, and multiple capillary, venous or lymphatic ...malformations. KTS is associated with recurrent thromboembolic events. We reported herein five cases of chronic thromboembolic pulmonary hypertension (CTEPH) associated with KTS (age minimum–maximum 26–50 years old, 3 males/2 females). Hemodynamics showed severe pulmonary hypertension (PH) with pulmonary vascular resistance ranging from 5.6 to 18.3 Wood units (WU), associated with marked clinical impairment (NYHA functional class III or IV in 4 patients). Computed tomography (CT) of the chest and pulmonary angiography confirmed proximal CTEPH accessible to surgical intervention in one patient and distal forms of CTEPH in 4 patients. Evolution after pulmonary endarterectomy showed hemodynamic normalization, while the patients with distal CTEPH had severe outcomes with 2 early deaths after PH diagnosis (44 and 35 months respectively). One patient with distal CTEPH was still alive 16 years after diagnosis on specific PH therapy and one was transplanted after 15 years because of right heart failure (death after 12 months). Histological analysis of the lung explants showed typical chronic thromboembolic material specific for CTEPH. In conclusion, KTS may be complicated by severe CTEPH requiring careful anticoagulation and multidisciplinary follow-up in expert centers to screen for disease potentially accessible to endarterectomy. In the modern management era of CTEPH, balloon pulmonary angioplasty will certainly be an interesting option in patients with inoperable disease.
Type 1 neurofibromatosis is one of the most common genetic diseases, with an incidence of 1/3500 live births. Its diagnosis primarily relies on the clinical features of the condition.
The life ...expectancy of these patients is reduced by 10 years, on average, compared to the general population. Type 1 neurofibromatosis has been shown to increase the risk of various types of neoplasia, primarily those affecting the neural crest. In addition, interstitial lung disease, lung cancer, and pulmonary hypertension have been observed during the third or the fourth decade of an adult's life.
There are only few case reports available that address the pulmonary complications of neurofibromatosis type 1. It is thus crucial to fully understand this rare disease and its potential complications in order to allow for early diagnosis so we are able to improve the quality of life and survival of those suffering from the condition.
The pulmonary complications of type 1 neurofibromatosis can be severe and life-threatening. Patients with this condition should thus undergo regular clinical visits and examinations to allow pulmonary complications to be detected and treatment to be initiated as early as possible.
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