Scleroderma-Associated Pulmonary Arterial Hypertension

Pulmonary hypertension is a chronic and progressive condition associated with high blood pressure in the blood vessels supplying the lungs, or the pulmonary arteries.

There are multiple types of pulmonary hypertension, classified into five groups by the World Health Organization (WHO). Group 1, or pulmonary arterial hypertension (PAH), is caused by the blood vessels narrowing, making the heart work harder to move blood through the lungs. The blood vessels can narrow for several reasons, including as a  complication of the autoimmune disease, scleroderma.

Scleroderma and PAH

In scleroderma, the patient’s own immune system starts to mistakenly damage healthy connective tissues and blood vessels. The body responds by producing too much collagen, a type of structural protein, that builds up and forms scar tissue in the affected areas.

If the affected area consists of pulmonary arteries, the scarring will cause them to stiffen and narrow, increasing the resistance to blood flow. Additionally, damage can trigger a response that leads to the overproduction of certain substances, such as endothelin, that cause the arterial wall muscles to contract even further. 

Ultimately, the narrowed pulmonary arteries cause significant resistance to blood moving through the lungs, leading to increased blood pressure. As a result, less blood can move through the lungs, reducing the amount of oxygen supplied to the rest of the body.

PAH is a common complication of scleroderma, with about 1 in 10 patients developing the condition.

Symptoms of scleroderma-associated PAH

Symptoms of scleroderma can manifest differently between patients, but typical signs include hardening of the skin, joint pain or stiffness, swelling of the hands or feet, and Raynaud’s phenomenon, painfully numb and cold fingers and toes.

Scleroderma-associated PAH shows similar symptoms to other forms of pulmonary hypertension. The most common initial symptoms include shortness of breath, fatigue, dizzy spells, chest pain, and swelling of the ankles or legs. The lack of oxygen in the blood can make it increasingly difficult for patients to exercise.

If untreated, scleroderma-associated PAH can lead to severe complications such as heart failure, due to the increased strain the heart is under.

Diagnosis of scleroderma-associated PAH

Patients with scleroderma should be screened annually for signs of pulmonary hypertension to increase the chance of early diagnosis.

A diagnosis will often start with an assessment of the patient’s ability to exercise, especially if symptoms such as shortness of breath are reported. The most common and accurate test if scleroderma-associated PAH is suspected is a right heart catheterization. This can directly measure the blood pressure in the pulmonary arteries and the heart.

Other tests frequently used in PAH diagnosis may also be done, such as echocardiography, which can produce images of the heart and lungs and can reveal abnormalities such as excess scarring.

Treatment of scleroderma-associated PAH

Patient’s with scleroderma-associated PAH may be given the same therapies used to treat other forms of PAH. These include medications designed to relax the walls of the pulmonary arteries, or vasodilation. For example, Letairis (ambrisentan) blocks endothelin from binding to receptors that signal for constriction in the pulmonary arteries. Other examples include: Flolan (epoprostenol), Remodulin (injected treprostinil), Tyvaso (inhaled treprostinil), Ventavis (iloprost), Tracleer (bosentan), Opsumit (macitentan), Revatio (sildenafil), Adcirca (tadalafil), Uptravi (selexipag), and Adempas (riociguat).

Patients may also benefit from oxygen therapy to improve oxygen levels in the blood and temporarily reduce shortness of breath. Anticoagulants, which prevent blood clots from forming that could further restrict blood flow, could also be used. Diuretics can help reduce swelling.


Pulmonary Hypertension News is strictly a news and information website about the disease. It does not provide medical advice, diagnosis or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.

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