The Cardiopulmonary System
Lupus is an autoimmune disease that can affect almost any part of your body, most often your joints, skin, kidneys, heart, lungs, blood, or brain.
Your heart, blood vessels, and lungs make up your cardiovascular/pulmonary network: "cardio" refers to the heart, "vascular" refers to the arteries, veins, and capillaries, and “pulmonary” refers to the lungs. Your blood circulates through this vast system, transporting oxygen and other elements needed for your cells and tissues to function properly. Cardiologists are the physicians who specialize in the heart. Pulmonologists are the physicians who specialize in the lungs.
Heart disease is a major complication of lupus and is now a leading cause of death among people with lupus. Blood tests, chest X-rays, an electrocardiogram (EKG), or an echocardiogram may be used to find out if you have a heart condition caused by lupus.
The most common way that lupus affects the heart is through inflammation of the pericardium, the sac that surrounds your heart. The symptoms of pericarditis that you may experience are sharp pain in your chest and, occasionally, shortness of breath. Pericar-ditis usually does not damage your heart’s ability to function because it does not directly involve the heart tissue. However, inflammation that is chronic (long-lasting) can scar the heart tissue, which can interfere with the heart’s ability to pump blood.
Lupus can cause inflammation of the myocardium, the muscle tissue of your heart. The symptoms are chest pain and an unexplained rapid or irregular heart beat. Myocarditis is often seen when there is inflammation in other muscles in the body.
However, myocarditis can be caused by viral, bacterial, and fungal infections. Because lupus itself creates an added risk for developing infections -- especially if you are taking certain immunosuppressive drugs -- you are at increased risk for this type of myocarditis.
Though serious heart muscle disease is not commonly caused by lupus, heart failure can occur if your heart does not have the strength to pump enough blood to the different tissues and organs.
The endocardium is the tissue that lines the inner walls of your heart and the valves that separate the heart’s different chambers. Lupus can cause inflammation of the endocardium. Lupus endocarditis usually causes the surfaces of the heart valve to thicken or develop wart-like growths (lesions). These lesions can become infected, a condition called bacterial endocarditis. A lesion also could break off and travel to the brain to form a blood clot. Both of these possibilities are potentially very dangerous.
Coronary Artery Disease
The coronary arteries move blood to and from your heart. Over time, fatty molecules and other materials may attach to the walls of these blood vessels and form plaque, which makes the blood vessels narrower and restricts blood flow. This condition is known as atherosclerosis. A decrease in blood flow can cause angina (chest pain). However, if the blood flow to your heart is interrupted -- either by plaque or by a blood clot that develops when plaque breaks off -- you could be at risk for a heart attack.
When you have lupus you are at increased risk for coronary artery disease. This is partly because people with lupus have more risk factors, which may include:
- hypertension from kidney disease or corticosteroid use
- elevated cholesterol levels from corticosteroid use
- type 2 diabetes from corticosteroid use
- an inactive, sedentary lifestyle due to fatigue, joint problems, and/or muscle pain
However, even after taking these risk factors into account, people with lupus are more likely to develop atherosclerosis. You can help reduce your chances of heart attacks and other complications from coronary artery disease in several ways:
- control the risk factors
- control the lupus disease activity
- talk to your doctor about reducing or stopping your corticosteroid use
Blood is made up of many different parts, but those that are most often affected by lupus are the red blood cells, the white blood cells, and the platelets.
Anemia occurs when not enough oxygen is transported to the tissues in your body. There are several possible causes for this:
- too few red blood cells
- not enough hemoglobin
- not enough blood circulating in the body
In most cases, lupus-related anemia occurs because your body is not producing enough red blood cells. However, sometimes antibodies target healthy red blood cells for destruction. This condition is called hemolytic anemia, or simply hemolysis. Hemolysis can cause a yellowish color in your skin and eyes and is a serious condition.
Anemia may also be caused by aspirin, ibuprofen, and other non-steroidal anti-inflammatory drugs (NSAIDs) used to treat lupus. These drugs can irritate the lining of your stomach, which may lead to bleeding and loss of red blood cells. Feeling very tired is the earliest and most common symptom of anemia.
Leukopenia and Neutropenia
If you have too few white blood cells in your body you may develop leukopenia and/or neutropenia (also called granulocytopenia). Both are common in people with active lupus. Low numbers of white blood cells may be due to an infection in your body, or due to certain drugs used to control lupus that work by suppressing your immune system.
If you have low platelet numbers you may develop thrombocytopenia. This condition is almost always caused by antibodies that attack and destroy healthy platelets. The symptoms of a low platelet count are bruising, nosebleeds, or the appearance of tiny red bleeding points in your skin (especially on your lower legs) called petechiae (pronounced pah-TEE-kee-eye). Although thrombocytopenia is common in lupus, serious bleeding usually does not occur.
The blood’s ability to form clots at the site of wounds is absolutely essential. Sometimes, unnecessary clots form inside the blood vessels and prevent the blood from circulating, a condition called thrombosis. If a thrombus, or blood clot, breaks off and travels through your blood, it is called an embolus or embolism.
Thrombosis is a serious and frequent complication of lupus. A clot in the veins of the lower leg can make walking painful and difficult, and may also produce an embolism that travels up into another part of your body. A clot in the lungs can cause high blood pressure (hypertension). A clot in a blood vessel of the brain can cause a stroke. During pregnancy, blood clots can lodge in the placenta and disrupt nutrition to the fetus.
Most blood clots in lupus are associated with antibodies in the blood to substances called phospholipids. People with lupus who have antiphospholipid antibodies are much more likely to have blood clotting problems.
The Circulatory System
Inflammation in a small blood vessel like a capillary may cause that vessel to break and bleed inside the tissue. Inflammation that occurs in the skin may appear as a small red or purple dot. Inflammation that takes place in other tissues can be extremely serious, especially within the brain. Vasculitis is caused by inflammation of the blood vessel walls. The symptoms of lupus-induced vasculitis that you may experience can vary depending upon which tissues are involved, but may include:
- feeling ill
- poor appetite
- weight loss
- blurry vision
- behavioral disturbances
The Lungs and Pulmonary System
Inflammation caused by lupus may affect the lungs in many ways, and can involve the membrane lining of the lungs, the lungs themselves, the blood vessels within the lungs, and the diaphragm.
The most common way that lupus can affect your lungs is through inflammation of the pleura, the lining that covers the outside of the lungs. The symptom of pleuritis that you may experience is severe, often sharp, stabbing pain in a specific area or areas of your chest. The pain, which is called pleurisy, is made worse when you take a deep breath, cough, sneeze, or laugh. You may also experience shortness of breath. Sometimes an abnormal amount of fluid will build up in the space between your lungs and your chest wall; when it leaks out it is called a pleural effusion. Pain from pleurisy, with or without effusions, is found in 40 to 60 percent of people with lupus.
The term for inflammation within the lung tissue is pneumonitis. The symptoms of pneumonitis that you may experience are fever, chest pain, shortness of breath, and cough. An infection caused by bacteria, virus, or fungi is the most common cause of pneumonitis.
Chronic Diffuse Interstitial Lung Disease
When inflammation in the lungs is chronic, it can cause scarring. This scar tissue can prevent oxygen from moving easily from your lungs into your blood and may cause diffuse (widespread) interstitial lung disease. The symptoms that you may experience include a chronic dry cough, chest pain, and difficulty breathing during physical activity.
Blood clots that block the arteries leading to the lungs are called pulmonary emboli. These blood clots will cause chest pain and shortness of breath, but can also lead to a decrease in oxygen flow in your lungs. You are at increased risk for pulmonary emboli if you have antiphospholipid antibodies, vascular damage, and/or an inactive lifestyle.
Frequently Asked Questions
I've read a little about polycythemia -- does a lupus patient develop this at times?
No, it is not common. It's extremely rare. Research on the occurrence of this finds only two case reports of polycythemia in lupus patients. So there is no connection between the two. Lupus is an autoimmune disorder and polycythemia is a condition in which there is increased blood volume and high hemoglobin levels (too many red cells).
There are two kinds of polycythemia: primary (inherited) and secondary (usually acquired from a medical condition that causes low oxygen in the blood such as lung conditions, smoking, etc.) Mild polycythemia is common in people who smoke.
I would like to know; what is lupus serositis?
Serositis is the inflammation of the serous membranes (sacs) that surround organs. Serositis is one of the symptoms of lupus listed in the criteria of the American College of Rheumatology. This symptom is known to affect up to 45 percent of people with lupus. Examples of serositis that can be affected by lupus are pleurisy an inflammation of the membrane that surrounds both lungs and pericarditis an inflammation of the sac (pericardium) that surrounds the heart.
My understanding is that lupus patients are at increased risk of heart disease and strokes. If this is correct, is it reasonable to start statin therapy?
Until we better understand the reason that lupus patients are at increased risk for strokes and heart attacks, we encourage doctors to treat all traditional cardiovascular risk factors such as high blood pressure, high cholesterol, smoking, etc. It is reasonable to use statins to decrease cholesterol levels.