Research indicates that inflammation underscores a significant percentage of heart disease, and some professionals believe that it may be the source of many complications of aging. Our panelists explore the relationship between inflammation and disease, and what new treatments lay ahead.
The immune system and inflammation
The immune system is the body's defense system against infection and disease. The system sends specialized cells to locate, mark, and destroy harmful substances called antigens (such as bacteria, viruses, poisons) that can cause disease and infection.
Inflammation, which is also known as an inflammatory response, is one of the ways the immune system responds to the presence of antigens. Essentially, it means that the immune system (specifically white blood cells) has produced certain disease-fighting chemicals and sent them to the areas of the body affected by the antigens. The chemicals fight the antigens, but also cause the redness, swelling, and pain that we recognize as symptoms of inflammation.
Inflammation is normally acute; that is, it begins as the body starts to fight the antigens and ends when the fight is won and the immune system stops producing the chemicals. Chronic inflammation means the body continues to produce the chemicals that cause inflammation. The immune system is, in effect, mistakenly attacking the body's own healthy tissues and organs. This leads to autoimmune diseases, illnesses caused by the body's own defense system.
There are many types of autoimmune diseases. They may not be able to be cured, but they can be treated and their symptoms reduced and controlled.
- The immune system defends the body against harmful substances, called antigens, (such as bacteria, viruses, poisons, etc.) that can cause infection and disease. The system sends specialized cells (various varieties of white blood cells) to locate, mark, and destroy these antigens.
- Inflammation is one of the immune system's responses to the presence of antigens. The system produces antigen-fighting chemicals and sends them to the areas affected by the antigens. But their presence also creates the symptoms we associate with inflammation: swelling, redness, warmth, pain.
- Though unpleasant, normal inflammation is part of the disease-fighting process.
- An autoimmune disease results from the immune system attacking the body's own "native" organs, tissues, and cells. For reasons not yet understood, the immune system fails to recognize them, sees them as foreign, and attacks them.
- There are more than 80 autoimmune diseases. Because the immune system has specialized cells to protect every part of the body, it can also attack every part of the body.
- Among the best-known autoimmune diseases are: rheumatoid arthritis, lupus, multiple sclerosis, insulin-dependent (type 1) diabetes, Crohn's disease, and ulcerative colitis.
- The CRP test measures the amount of C-reactive protein in the blood; a higher level of it suggests the presence of inflammation, but does not tell where the inflammation is or what's causing it.
- Treatment for inflammatory or autoimmune diseases depends on the specific disease and the severity of its symptoms, as well as on the person's age, overall health, medical history, and the other drugs s/he is taking.
- Treatment can include various medicines, exercise, diet changes, and rest.
Ask Your Doctor
This list of questions is a good starting point for discussion with your doctor; however, it is not a comprehensive list.
- I have the following symptoms: ___________. Could I have an autoimmune disease?
- What tests should I take to help diagnose my symptoms?
- Should I have a CRP test?
- What were the results of the tests?
- What treatments are appropriate for me? What do you recommend? Why?
- How often will I receive treatment?
- How long will the treatment last?
- How well has this option worked for others?
- What are the potential benefits of this treatment?
- What are the risks or side effects that I should expect?
- If I experience side effects, how long will they last and how can they be managed?
- Are the possible side effects of this treatment serious enough to interfere with continuing therapy?
- What lifestyle changes (such as diet) should I make to control my condition?
- What medicines/drugs should I take?
- How often should I take this medicine?
- Should I take this medicine with food or between meals?
- What side effects might occur?
- I'm experiencing some side effects from my medication. Is that normal?
- Should I take this medicine with the other prescription medicines I take? Will it interact with them?
- Will this medicine interact with over-the-counter (non-prescription) medicines or supplements I take?
- Where can I find clinical drug trials I can participate in?
Key Point 1
The immune system is the body's defense system against infection and disease. Autoimmune disease develops when this system attacks healthy cells in joints, nerves and connective tissue.
It's the job of the human immune system to protect the body against harmful substances (such as bacteria, viruses, toxins, cancer cells, blood or tissues from another person or species) that can cause disease or infection. These substances are called antigens. The immune system is very complex, consisting of organs and cells that have various specialized functions within the overall fight against antigens.
The organs, found throughout the body, are called "lymphoid organs." They're connected by tubes or vessels, similar to blood vessels. But instead of blood, a transparent fluid called lymph flows through them. The specialized cells that are part of the immune system, called "immune cells," are actually various types of white blood cells.
These cells are born in the bone marrow and grow to maturity there or elsewhere. They are carried to the organs they're defending, or to the antigens they are attacking, by the lymph and blood that circulates through the body. Some of them produce antibodies. Antibodies find and mark the antigens so other immune cells can locate and destroy them.
The key to the immune system is its ability to recognize what is foreign - what doesn't belong to the person. (That's why transplant patients need medicines that inhibit their immune systems. The immune system "sees" a transplanted organ as being foreign, which, in fact, it is; it comes from another person. Therefore, the immune system wants to attack and destroy it; anti-rejection medicines weaken the immune system so it can't.)
Sometimes, for reasons we don't yet understand, the immune system fails to recognize the body's own organs, tissues, and cells. It "sees" them as being foreign, and attacks them. This attack is an autoimmune disease. Because the immune system has specialized cells to protect every part of the body, it can also attack every part of the body. In fact, there are more than eighty autoimmune diseases.
This list of autoimmune diseases, organized by the system or organ attacked, is only a small sample of them, and includes some of the better known ones:
Connective Tissue Diseases
- Rheumatoid Arthritis: This is the second most common form of arthritis (after osteoarthritis). The immune system attacks and inflames the tissues of the joints, which creates pain, inflammation, swelling, and redness in joints. It also can affect the heart, lungs, and eyes.
- Systemic Lupus Erythematosus (SLE or lupus): This is an inflammation of the body's connective tissues and can strike every organ.
- Systemic Sclerosis (Scleroderma): In this disease, immune cells create scar tissue in the skin, internal organs, and small blood vessels.
- Sjögren's Syndrome (Sjögren's disease): This chronic but slowly progressing condition is an inability to produce tears or saliva.
- Multiple Sclerosis (MS): One of the best-known and most debilitating autoimmune diseases, MS attacks the central nervous system leading to numbness, weakness, tingling, or even paralysis in one or more limbs, as well as problems with impaired vision and eye pain, tremor, lack of coordination or unsteady gait and rapid involuntary eye movement.
- Myasthenia Gravis: This chronic autoimmune disorder leads to gradual muscle weakness; it often appears first in the face.
- Guillain-Barre Syndrome: This illness causes severe nerve damage. Two-thirds of all cases occur after a viral infection.
- Hashimoto's Thryoiditis: This disease, much more common in women than men, affects the thyroid, the gland that helps set the rate of metabolism.
- Grave's Disease: Another thyroid condition, it causes the gland to produce too much thyroid hormone and is a relatively common condition, suffered by about 13 million people.
- Insulin-Dependent (Type 1) Diabetes: This disease causes the pancreas to produce too little insulin; it is more common in children and younger adults.
- Inflammatory Bowel Disease: This term actually encompasses two small intestine disorders:
- Crohn's disease, whose symptoms include persistent diarrhea, abdominal pain, fever, and general fatigue
- Ulcerative colitis, whose symptoms include bloody diarrhea, pain, urgent bowel movements, joint pains, and skin lesions
Blood Vessel Diseases
- Vasculitis Syndromes: This term refers to a large group of diseases involving inflammation of and damage to blood vessels of any size, kind, or location; these diseases can happen alone or be combined with others.
- There are a number of autoimmune diseases of the blood itself, including autoimmune hemolytic anemia. In this disease, antibodies attack and kill red blood cells.
- There are also several autoimmune skin diseases. In fact, skin problems are often the first sign of an autoimmune condition. Psoriasis is one of the most common of these skin diseases and is caused by a speeding up of skin cell production, so that thick, scaly patches appear on the skin.
Key Point 2
Inflammation can be a lifesaving response of our body's defense system. Sometimes, however, inflammation goes awry-and bad things happen.
Sometimes people think inflammation is the same thing as infection. It isn't. "Infection" refers to a state of disease, a set of symptoms caused by antigens in the body.
Inflammation, on the other hand, is one of the immune system's responses to the presence of antigens. It's part of the body's disease fighting and healing mechanisms.
What causes inflammation? Through a complex series of processes, the immune system (specifically white blood cells) produces certain chemicals and sends them through the body to the areas affected by the antigens. (These chemicals include the cytokines interleukin and interferon, C-reactive protein, hormones known as prostaglandins, and free radicals.) These chemicals are, of course, meant to fight the antigens. But their presence increases blood flow to the areas, and they may also leak into the affected tissues. The result is inflammation; that is, the affected area can become swollen, red, warm and painful.
Not all of these symptoms are necessarily present in every case of inflammation. Despite its unpleasantness, inflammation is a necessary step in the fight against disease. Normally, when antigens have been destroyed, the immune system recognizes that it has "done its job" and stops producing the chemicals that cause inflammation. This type of short-term inflammation is called "acute" inflammation. It starts when there's an injury, infection, or other event that causes antigens to be present, and ends when the injury starts healing and the antigens are killed.
However, when the immune system fails to operate correctly, it can continue to produce the "pro-inflammatory chemicals." That's when inflammation becomes a chronic, or long-lasting, condition. One result of chronic inflammation can be pain, caused by tissues swelling and pressing on nerves. Another result can be damage to the tissues and one or more autoimmune diseases. For information about autoimmune diseases, see Key Point 1.
Another term to note is "systemic inflammation," which means there is inflammation throughout the body.
Diseases caused by chronic inflammation are diagnosed by considering:
- Medical history
- Physical exam
- Results to appropriate tests, such as x-rays or other imaging techniques
Key Point 3
There are things we can do to reduce chronic inflammation. The right medication, diet, and exercise are important.
One technique for diagnosing inflammation is known as the CRP test.
CRP, or C-Reactive Protein, is one of the chemicals produced by the immune system to fight harmful substances (antigens) in the body; it's also one of the chemicals that leads to inflammation. The CRP test measures the amount of this protein in the blood (normally there is none). Like other blood tests, it requires taking a small sample of blood and sending it to the lab for analysis.
A positive CRP test (that is, a test that shows there is CRP in the blood) is considered "non-specific." That means it suggests the presence of inflammation, but does not indicate where that inflammation is, or what disease or condition is causing it. Among the diseases that could cause an elevated CRP level are:
- Connective tissue disease
- Heart attack
- Inflammatory bowel disease (IBS)
- Rheumatoid arthritis
- Rheumatic fever
Two other "conditions" can also cause positive CRP results:
- Being in the last half of a pregnancy
- Using oral contraceptives
On the other hand, for reasons we don't yet understand, it is possible to have certain inflammatory diseases, such as lupus and rheumatoid arthritis, and still have a normal CRP result. However, if you know you have a specific inflammatory or autoimmune disease, such as rheumatoid arthritis, and are taking a specific drug to combat it, the CRP test can monitor its effectiveness. In other words, taking the drug should lower the CRP level.
Two other diagnostic tests should also be mentioned.
- ESR (erythrocyte sedimentation rate or sed rate), a blood test often done at the same time as the CRP test, is another non-specific indicator of inflammation.
- hs-CRP (high-sensitivity C-reactive protein) measures very low amounts of CRP in the blood.
Recent studies suggest that CRP levels are raised in people with heart diseases. We don't know yet if CRP in the blood is a result of heart disease (and therefore a "marker" or indicator of its presence) or a cause of it. But the hs-CRP test is now often used to determine one's risk of heart disease. According to theAmerican Heart Association
- You are at low risk of developing cardiovascular disease if your hs-CRP level is lower than 1.0mg/L.
- You are at average risk of developing cardiovascular disease if your levels are between 1.0 and 3.0 mg/L.
- You are at high risk for cardiovascular disease if your hs-CRP level is higher than 3.0 mg/L.
Treatment for inflammatory or autoimmune diseases depends on the specific disease and the severity of its symptoms, as well as on the person's age, overall health, medical history, and the other drugs s/he is taking. Treatment may not cure the condition, but it can relieve pain and, when joints are involved (as in rheumatoid arthritis), help strengthen muscles and joint movement, and reduce stress on the joints.
In general, treatments include rest, exercise, and various medicines including:
- Non-steroidal anti-inflammatory drugs (NSAIDs), such as aspirin, ibuprofen or naproxen and the COX-2 inhibitors, such as celecoxib (Celebrex®)
- Prolonged use of the traditional NSAIDs can cause intestinal problems, such as bleeding and ulcers
- The COX-2 inhibitors do not have this side effect, but they have been associated with increasing the risk for heart attack and stroke
- Steroids (corticosteroids), such as prednisone
- They are effective at relieving symptoms but can have serious side effects
- Anti-malarial medications, such as hydroxychloroquine
- Statins, a class of drugs used to lower cholesterol levels in the blood, that have also been effective in combating inflammation
- Other medications including methotrexate, sulfasalazine, leflunomide, anti-TNF medications, cyclophosphamide and mycophenolate
- Proteins produced by recombinant DNA technology, such as:
- Recombinant protein C, that helps the body dissolve tiny clots caused by inflammation
- Etanercept (Embrel®)
- Infliximab (Remicade®)
Other treatments include:
- Vitamin or hormone supplements, such as thyroid supplements and insulin injections (for conditions that demand them)
- Blood transfusions (for blood diseases)
A healthy diet can also help fight inflammation. General guidelines for a healthy diet include:
- Fruits and vegetables
- More fish, less meat
- "Good" oils, such as olive oil and canola oil
- Antioxidants are nutrients and other substances that protect cells in the body from the damage caused by "oxygen free radicals" (molecules that seek to become oxidized, a process that harms body tissues and has been linked to many diseases including stroke, heart disease, and cancer). Antioxidants are found naturally in food but are also available as dietary supplements (antioxidates found in food work far better than pill supplements)
- Important antioxidants include:
- Vitamins A, C, E and beta-carotene (found in carrots)
- Lycopene (found in tomatoes)
- Flavonoids (found in ginkgo biloba, black cherries, blackberries, bilberries and blueberries)
- Quericetin (a specialized flavonoid found in apples, onions, tea and red wine)
- Coenzyme Q10 (a vitamin-like substance found in soy, whole grains, mackerel, and chicken)
Specific guidelines for an "anti-inflammatory diet" include:
- Limiting foods that contain ingredients that promote production of inflammatory chemicals and chronic inflammation, such as:
- Omega-6 oils (found in cooking oils)
- Certain carbohydrates, particularly refined sugars and white flour
- Saturated fats and trans-fats found in crackers and baked goods
- Increasing intake of omega-3 oils and monounsaturated fats found in fatty fish
- Increasing intake of low starch vegetables, such as broccoli, cauliflower, and salad greens, that contain anti-inflammatory compounds
Finally, living a healthy lifestyle not only benefits one's general well-being, but can also reduce the effects of inflammation. This means emphasizing exercise, non-smoking, moderation in alcohol use, and the healthy diet suggested above. Specifically:
- Start and maintain a program of regular physical exercise
- Stop smoking
- Stop drinking alcohol heavily
- Keep your blood pressure under control
- Keep your cholesterol under control
Conduct an off-site search for Inflammation information from MedlinePlus. These up-to-date search results are based on search terms specific to Second Opinion Key Points.