Dépistage de l’hypertension pulmonaire au cours de la sclérodermie systémique : une stratégie optimale encore à définir

Pulmonary hypertension in connective tissue diseases: What every CTD specialist should know - but is afraid to ask!

Pulmonary hypertension (PH) is a possible complication of connective tissue diseases (CTDs), especially systemic sclerosis (SSc), systemic lupus erythematosus (SLE) and mixed connective tissue disease (MCTD). It is defined by an elevation of the mean pulmonary arterial pressure above 20mmHg documented during a right heart catheterization (RHC). Due to their multiorgan involvement, CTDs can induce PH by several mechanisms, that are sometimes intricated: pulmonary vasculopathy (group 1) affecting arterioles (pulmonary arterial hypertension, PAH) and possibly venules (pulmonary veno-occlusive-like disease), left-heart disease (group 2), chronic lung disease (group 3) and/or chronic thromboembolic PH (group 4). PH suspicion is often raised by clinical manifestations (dyspnea, fatigue), echocardiographic data (increased peak tricuspid regurgitation velocity), isolated decrease in DLCO in pulmonary function tests, and/or unexplained elevation of BNP/NT-proBNP. Its formal diagnosis always requires a hemodynamic confirmation by RHC. Strategies for PH screening and RHC referral have been extensively investigated for SSc-PAH but data are lacking in other CTDs. Therapeutic management of PH depends of the underlying mechanism(s): PAH-approved therapies in group 1 PH (with possible use of immunosuppressants, especially in case of SLE or MCTD); management of an underlying left-heart disease in group 2 PH; management of an underlying chronic lung disease in group 3 PH; anticoagulation, pulmonary endartectomy, PAH-approved therapies and/or balloon pulmonary angioplasty in group 4 PH. Regular follow-up is mandatory in all CTD-PH patients.

[Updates in systemic sclerosis pathogenesis: Toward new therapeutic opportunities]

Systemic sclerosis is a rare connective tissue disease characterized by skin and several internal organ fibrosis, systemic vasculopathy and immune abnormalities. Even if fibroblasts and endothelial cells dysfunction, as well as lymphocytes and other immune cells implication are now well described, the exact origin and chronology of the disease pathogenesis remain unclear. Oxidative stress, influenced by genetic and environmental factors, seems to play a key role. Indeed, it seems to be implicated in the early phases of fibrosis development, vasculopathy and in immune tolerance abnormalities shared by all patients, although disease expression is heterogeneous. To date, no curative treatment is available. Even if immunosuppressive treatment or drugs acting on vascular system are proposed for some patients, overall, treatment efficiency remains modest. Only autologous hematopoietic stem cells transplantation, reserved for patients with severe or rapidly progressive fibrosis, has recently demonstrated efficiency, with lasting regression of fibrosis. Nevertheless, this treatment can expose to important, life-threatening toxicity. In the last decade, new mechanisms implicated in the pathogenesis of systemic sclerosis have been unraveled, bringing new therapeutic opportunities. In this review, we offer to focus on recent insights in the knowledge of systemic sclerosis pathogenesis and its implication in current and future medical care.