Effect of bosentan in pulmonary hypertension development in systemic sclerosis patients with digital ulcers

Can we define difficult-to-treat systemic sclerosis?

INTRODUCTION

Systemic sclerosis (SSc) is a chronic autoimmune rheumatic disease characterized by microvascular alterations, immunopathology, and widespread fibrosis involving various organs. It is considered difficult to treat due to several reasons: complex pathogenesis, heterogeneity, late diagnosis, limited treatment options for certain organ manifestations, lack of personalized medicine.

AREAS COVERED

This review presents the heterogeneity, survival and organ manifestations with their risk factors of systemic sclerosis and their current treatment options, while drawing attention to difficult-to-treat forms of the disease, based on literature indexed in PubMed.

EXPERT OPINION

Despite recent advances in the management of SSc over the last decades, the disease presents significant morbidity and mortality. Although available treatment protocols brought significant advancements in terms of survival in SSc-associated interstitial lung disease and pulmonary arterial hypertension, less success has been achieved in the treatment of Raynaud's phenomenon and digital ulcers and the results are modest in case of heart, gastrointestinal, and renal manifestations. There are patients who do not respond to treatment and deteriorate even with adequate therapy. They can be considered difficult-to treat (D2T) cases. We have created a possible score system based on the individual organ manifestations and highlighted treatment options for the D2T SSc category.

Systemic Sclerosis-Associated Pulmonary Arterial Hypertension: From Bedside to Bench and Back Again

Systemic sclerosis (SSc) is a heterogeneous disease characterized by autoimmunity, vasculopathy, and fibrosis which affects the skin and internal organs. One key aspect of SSc vasculopathy is pulmonary arterial hypertension (SSc-PAH) which represents a leading cause of morbidity and mortality in patients with SSc. The pathogenesis of pulmonary hypertension is complex, with multiple vascular cell types, inflammation, and intracellular signaling pathways contributing to vascular pathology and remodeling. In this review, we focus on shared molecular features of pulmonary hypertension and those which make SSc-PAH a unique entity. We highlight advances in the understanding of the clinical and translational science pertinent to this disease. We first review clinical presentations and phenotypes, pathology, and novel biomarkers, and then highlight relevant animal models, key cellular and molecular pathways in pathogenesis, and explore emerging treatment strategies in SSc-PAH.

Comprehensive Update on Synthetic Aspects of Bosentan Derivatives

Bosentan and its analogues were first reported as endothelin (ET) receptor antagonists in US patent No. 5, 292,740 in 1994. Bosentan synthesis has been reported by employing different methods from the reaction between (4,6-dichloro-5-(2-methoxyphenoxy)-2,2'-bipyrimidine and 4- (tert-butyl) benzenesulfonamide and 4-(tert-butyl)-N-(6-chloro-5-(2-methoxyphenoxy)-[2,2'- bipyrimidin]-4-yl) benzenesulfonamide in the form of different salts like potassium salt, ammonium salt, sodium salt, and free, on its reaction with ethylene glycol. Several changes have been observed in the chemistry of the involved intermediate synthesis, particularly coupling chemistry, to produce bosentan derivatives with high purity and yield.

Kidney Involvement in Systemic Sclerosis

Background: Systemic sclerosis is a chronic multisystem autoimmune disease, characterized by diffuse fibrosis and abnormalities of microcirculation and small arterioles in the skin, joints and visceral organs. Material and Methods: We searched for the relevant articles on systemic sclerosis and kidney involvement in systemic sclerosis in the NIH library of medicine, transplant, rheumatologic and nephrological journals. Results: Half of patients with systemic sclerosis have clinical evidence of kidney involvement. Scleroderma renal crisis represents the most specific and serious renal event associated with this condition. It is characterized by an abrupt onset of moderate to marked hypertension and kidney failure. Early and aggressive treatment is mandatory to prevent irreversible organ damage and death. The advent of ACE-inhibitors revolutionized the management of scleroderma renal crisis. However, the outcomes of this serious complication are still poor, and between 20 to 50% of patients progress to end stage renal disease. Conclusions: Scleroderma renal crisis still represents a serious and life-threatening event. Thus, further studies on its prevention and on new therapeutic strategies should be encouraged.

Prediction and primary prevention of major vascular complications in systemic sclerosis

OBJECTIVE

In Systemic Sclerosis (SSc), vasculopathy is the background of major vascular complications (MVCs), like digital ulcers (DUs), pulmonary arterial hypertension (PAH) and scleroderma renal crisis (SRC). We aimed to identify the predictors and to test the primary preventive effect of vasoactive/vasodilating drugs (VVD) for the development of MVCs in SSc MVCs-naïve patients.

METHODS

patients fulfilling the ACR/EULAR 2013 classification criteria for SSc without history of MVCs were eligible. Data about clinical manifestations, laboratory and instrumental assessments and treatments were retrospectively collected at baseline and latest available follow-up.

RESULTS

134 SSc patients were enrolled (mean age 56.5 years ± 14.2, females 88.1%, limited subset 61.9%, ACA positivity 60.4%). In a mean of 43 ± 19 months of follow-up 12 (9.0%) patients developed at least 1 MVC (10 DU, 2 PAH and 1 SRC). Dyspnoea and arthritis at baseline were independent predictors for MVCs development (p = 0.012, and p = 0.002 respectively). No primary preventive effect of VVD on MVCs development was found. However, sildenafil reduced the renal resistive index increase (p = 0.042) and alprostadil slowed the DLco decline (p = 0.029). Both iloprost and angiotensin-receptor blockers (ARBs) delayed MVCs development, while angiotensin converting enzyme inhibitors (ACEi) determined an earlier onset of such MCVs.

CONCLUSIONS

in SSc patients, our data confirm the role of arthritis and dyspnea as independent predictors of major vascular complications, in particular in MVCs-naïve patients. Prostanoids, sildenafil and ARBs, even in absence of a primary preventive action, might help in slowing disease progression and postponing the onset of MVCs.