Pulmonary hypertension (PH) — particularly pulmonary arterial hypertension (PAH) — is often found in people with a connective tissue disease (CTD). Also known as collagen vascular diseases, CTDs are autoimmune diseases that affect the pulmonary vascular system — the blood vessels of the heart and lungs. CTD-PAH refers to people who have PAH as a result of their CTD.
This article will cover the relationship between PAH and various CTDs and how to manage these conditions so you or your loved one can feel as healthy as possible and have a better quality of life.
CTDs represent more than 200 different types of chronic conditions and autoimmune diseases that affect the body’s connective tissues. Connective tissues are made up of proteins called collagen and elastin that help support the body’s skin, bones, tendons, ligaments, cartilage, and blood vessels, as well as the corneas in the eyes. In CTDs, these proteins are inflamed, causing abnormal functioning of the connective tissues and their surrounding areas.
Types of CTDs include:
In mixed connective tissue disease (MCTD) — also called Sharp syndrome — symptoms and features of various CTDs coexist.
Over the past several years, researchers have found that people diagnosed with a CTD — specifically scleroderma, lupus, and MCTD — are at a greater risk of developing PAH. Scleroderma is the most common CTD leading to PAH, contributing to nearly 75 percent of cases of people with CTD-PAH. Lupus and MCTD are each associated with 8 percent of cases of CTD-PAH.
Among the various types of pulmonary hypertension, group I PH (PAH) most commonly develops in people with CTDs. Groups II through V of PH can also develop, however. Notably, CTDs can cause other cardiovascular (heart-related) and pulmonary (lung-related) diseases and complications aside from PAH.
CTDs are thought to be caused by a complex combination of genetic and environmental factors.
Environmental risk factors can include:
For many people with CTDs, however, the cause remains unknown.
Several factors may explain the connection between CTDs and PAH.
Scientists have discovered that specific antibodies (proteins produced by the immune system) contribute to PAH developing alongside CTDs. In scleroderma associated with PAH, antibodies target the endothelial cells (which line all the body’s blood vessels). This leads to an overproduction of collagen in the blood vessels and internal organs (e.g., lungs), causing hardening, tightening, and scar-tissue formation. This can cause the pulmonary blood vessels to constrict (narrow) or change shape, increasing blood pressure in the lungs and raise the risk for right heart failure.
The vasoconstriction theory explains how low or high oxygen levels will activate the endothelial cells to either constrict or dilate (widen) the lung’s blood vessels. In both the tissues and the lungs, oxygen levels and other chemical mediators tightly regulate blood flow. Studies have found that specific antibodies disrupt the dilation process in the lungs, leading to increased blood pressure and decreased oxygen concentration in tissues (hypoxia). Researchers have found that about 42 percent of people with SLE-related PAH have high levels of these antibodies.
Researchers have found that genetic variations and mutations in specific proteins involved in the lung’s blood vessel system influence the development of PAH in people with CTDs. However, more large-scale studies are needed to confirm this finding.
There are many types of CTDs, and not everyone with PAH secondary to a CTD has the same diagnosis, symptoms, or treatments. As mentioned earlier, the most common CTDs related to PAH include scleroderma, lupus, and MCTD. In rare cases, rheumatoid arthritis, Sjögren’s syndrome, and idiopathic inflammatory myopathies are also seen in people with PAH.
Many myPHteam members who have PAH secondary to their CTD diagnosis experience a variety of symptoms. “I was diagnosed with pulmonary arterial hypertension, secondary to scleroderma,” wrote one myPAteam member. “I have shortness of breath, edema in my legs and ankles, persistent cough, and cataracts in both eyes.”
“My lupus affects my central nervous system, GI tract, and spleen. The past two years, I have also had peripheral nerve damage that has been affecting my kidneys,” wrote one member with PAH and lupus.
The first signs and symptoms of a CTD depend on the type of disease and the affected area of the body. Some people may experience fatigue, inflammation of fingers (or dactylitis), white or numb fingertips (Raynaud’s), joint pain, and muscle or joint weakness.
Symptoms of PAH in people with a CTD can be hard to identify. They can often be vague in the beginning and overlap with symptoms of the CTD. Increased fatigue or dizziness can often be early signs of PAH.
Symptoms caused by inflammation in the lungs can be serious and may lead to right heart failure if not treated. These include:
Speak to your rheumatologist or health care provider if you begin to experience new or worsening breathing symptoms. In recent years, screening people with scleroderma for PAH — even before they develop symptoms — has become commonplace. Screening can include blood work, lung function testing, and echocardiography to check heart function. Early detection of PAH in people with a CTD is key to improving survival rates and quality of life.
Decreasing your risk of PAH or treating CTD-PAH may involve lifestyle changes, medication, physical and occupational therapy, and sometimes surgery.
There are some ways to prevent or manage a PAH-related CTD through lifestyle changes, including:
People living with PAH and a CTD will work with a health care team that consists of a pulmonologist (lung specialist), rheumatologist, cardiologist, and other specialized providers. Depending on the type of CTD, experts may recommend the following medications for CTD-PAH:
A doctor may recommend a lung transplantation in cases where the lungs no longer function properly or where medications don’t help. This surgery requires a process of proper screening and approval from a team of specialists and health care providers.
Living with pulmonary hypertension has its challenges, and it can help to know that you’re not alone. By joining myPHteam — the social network for people with PH and their loved ones — you can connect with a growing team of more than 39,000 members from across the globe who understand life with pulmonary hypertension.
Are you living with pulmonary arterial hypertension related to a connective tissue disease? Share your experiences in the comments below or by posting on myPHteam.