Long-term administration of beraprost, an oral prostacyclin analogue, improves pulmonary diffusion capacity in patients with systemic sclerosis

Scleroderma pulmonary arterial hypertension: the same as idiopathic pulmonary arterial hypertension?

PURPOSE OF REVIEW

Pulmonary arterial hypertension (PAH) is a common complication of systemic sclerosis (SSc), which confers significant morbidity and mortality. The current therapies and treatment strategies for SSc-associated PAH (SSc-PAH) are informed by those used to treat patients with idiopathic PAH (IPAH). There are, however, important differences between these two diseases that impact diagnosis, treatment, and outcomes.

RECENT FINDINGS

Both SSc-PAH and IPAH are incompletely understood with ongoing research into the underlying cellular biology that characterize and differentiate the two diseases. Additional research seeks to improve identification among SSc patients in order to diagnose patients earlier in the course of their disease. Novel therapies specifically for SSc-PAH such as rituximab and dimethyl fumarate are under investigation.

SUMMARY

Although patients with SSc-PAH and IPAH present with similar symptoms, there are significant differences between these two forms of PAH that warrant further investigation and characterization of optimal detection strategies, treatment algorithms, and outcomes assessment.

Pulmonary hypertension in systemic sclerosis

OBJECTIVES

To discuss the clinical subtypes, pathogenesis, pathology, diagnostic evaluation, treatment options, and prognosis of pulmonary hypertension in systemic sclerosis (SSc-PH) and highlight its fundamental differences from idiopathic pulmonary arterial hypertension (IPAH).

METHODS

A Medline search for articles published between January 1969 and June 2010 was conducted using the following keywords: scleroderma, systemic sclerosis, pulmonary hypertension, pulmonary arterial hypertension, pulmonary veno-occlusive disease, pathogenesis, pathology, investigation, treatment, and prognosis. The essential differences from IPAH in pathogenesis and histopathologic findings were highlighted and the limitations of some of the investigations used were emphasized. The differences in response to currently accepted therapy and prognosis were also reviewed.

RESULTS

In scleroderma, pulmonary hypertension can be present in isolation or along with interstitial lung disease and left heart disease. In SSc-PH, the unique histopathologic findings in the lungs include intimal fibrosis, absence of plexiform lesions, and a high prevalence of pulmonary veno-occlusive disease-like lesions. Both "6-minute walk test" and NT-proBNP have their limitations in the evaluation of SSc-PH. For treatment, calcium channel blockers are ineffective and anticoagulation should be used with caution. Currently approved therapies are not as effective and prognosis is much worse in SSc-PH compared with IPAH.

CONCLUSIONS

SSc-PH is a complex condition with poorer response to therapy and worse outcome compared with that of IPAH. Recent findings have shed some light about the pathophysiology and pathogenesis of SSc-PH. Further research in this area is warranted to better understand the complex pathogenesis and devise better therapeutic strategies.

[Therapy of systemic sclerosis]

The therapy of systemic sclerosis (SSc) remains a challenge for dermatology, rheumatology, internal medicine, and other disciplines. Organ involvement, above all kidney and lungs, is a key therapeutic issue. The current developments in organ-specific therapy are the main topic of the article. Finally, possibilities of disease-modifying drugs and value of HSCT are discussed.

Prostanoid therapy for pulmonary arterial hypertension

Epoprostenol and the structurally related compounds treprostinil, iloprost, and beraprost are collectively referred to as prostanoids. The discovery of epoprostenol in 1976 and unequivocal demonstration of its efficacy in 1996 dramatically altered the approach to therapy for pulmonary arterial hypertension (PAH). Development of prostanoids available through multiple routes of administration and the discovery and development of other agents acting through alternative pathways continue to expand the array of therapeutic options. The use of prostanoids in combination with other PAH drugs and for treating pulmonary hypertensive disorders outside of the PAH classification are areas of ongoing research.

Low-dose epoprostenol improved pulmonary hypertension in a patient with systemic lupus erythematosus

A 43-year-old Japanese woman was referred to our hospital in 1997 because of Raynaud's phenomenon. Systemic lupus erythematosus was diagnosed on the basis of the presence of antinuclear antibody (1:1,280), anti-DNA antibody (1:640), anti-Sm antibody, antiphospholipid antibody, lymphopenia, and proteinuria. She developed pulmonary fibrosis in 1999 and pulmonary hypertension in 2001. In October 2002, a 24-hr continuous infusion of epoprostenol was started. Dyspnea, Raynaud's phenomenon, and pulmonary hypertension improved with low-dose epoprostenol (3.0 to 4.0 ng kg(-1) min(-1)). The patient could not tolerate larger doses of epoprostenol so 4.0 ng kg(-1) min(-1) was selected as the maintenance dose. The clinical course was uneventful at this dosage. It appears that pulmonary hypertension can be controlled with low-dose epoprostenol such as 3.0 to 4.0 ng kg(-1) min(-1) in some rheumatic patients.

New therapeutic strategies for systemic sclerosis--a critical analysis of the literature

Systemic sclerosis (SSc) is a multi-system disease characterized by skin fibrosis and visceral disease. Therapy is organ and pathogenesis targeted. In this review, we describe novel strategies in the treatment of SSc. Utilizing the MEDLINE and the COCHRANE REGISTRY, we identified open trials, controlled trials, for treatment of SSc from 1999 to April 2005. We used the terms scleroderma, systemic sclerosis, Raynaud's phenomenon, pulmonary hypertension, methotrexate, cyclosporin, tacrolimus, relaxin, low-dose penicillamine, IVIg, calcium channel blockers, losartan, prazocin, iloprost, N-acetylcysteine, bosentan, cyclophosphamide, lung transplantation, ACE inhibitors, anti-thymocyte globulin, and stem cell transplantation. Anecdotal reports were omitted.

Methotrexate, cyclosporin, tacrolimus, relaxin, low-dose penicillamine, and IVIg may be beneficial in improving the skin tightness in SSc. Calcium channel blockers, the angiotensin II receptor type 1 antagonist losartan, prazocin, the prostacyclin analogue iloprost, N-acetylcysteine and the dual endothelin-receptor antagonist bosentan may be beneficial for Raynaud's phenomenon. Epoprostenol and bosentan are approved for therapy of pulmonary hypertension (PAH). Other options under investigation include intravenous or aerolized iloprost. Cyclophosphamide (CYC) pulse therapy is effective in suppressing active alveolitis. Stem cell and lung transplantation is a viable option for carefully selected patients. Renal crisis can be effectively managed when hypertension is aggressively controlled with angiotensin converting enzyme (ACE) inhibitors. Patients should continue taking ACE inhibitors even after beginning dialysis in hope of discontinuing dialysis. Anti-thymocyte globulin and mycophenolate mofetil appear safe in SSc. The improvement in skin score and the apparent stability of systemic disease during the treatment period suggest that controlled studies of these agents are justified. Stem cell transplantation is under investigation for severe disease. Novel therapies are currently being tested in the treatment of SSc and have the potential of modifying the disease process and overall clinical outcome. The evaluation of these studies is still a difficult process.