Sarcoidosis & the Royal Free Hospital
What is sarcoidosis?
Sarcoidosis is an inflammatory disease characterised by the presence of non-caseating granulomas. A granuloma is a collection of inflammatory cells. They may occur in any organ or tissue, but the lungs, eyes and skin are most frequently affected. In most instances, the granulomas will heal with or without treatment. However, if the granulomas do not resolve and the inflammation persists, then scarring (or fibrosis) occurs leading to damage, or rarely failure of the organ involved.
Who does it affect?
Sarcoidosis is a relatively common condition, which is estimated to affect approximately 1 in 2000 people worldwide. It occurs in all races, but is most often seen in people of Afro-Caribbean, Scandinavian, German, Irish, Peurto Rican and Asian decent. Sarcoidosis affects both sexes and, although it can occur at any age, it most frequently occurs in people aged 20-40years.
What causes it?
The cause of sarcoidosis is unknown, but both genetic and environmental factors are thought to be involved. It is suspected that some patients have sequences of genes, which if stimulated by exposure to certain environmental agents (such as chemicals, bacteria or viruses), ‘switch on' the disease. Once activated, the patient's immune system is stimulated which results in inflammation and tissue damage. Although bacteria and viruses may play a role in the development of sarcoidosis, the disease itself is not contagious. There is also no strong evidence to suggest that relatives of patients with sarcoidoisis have an increased risk of developing the condition.
How will it affect me?
Sarcoidosis can affect any part of the body and the patient's symptoms generally reflect the organ or tissue involved. Patients can therefore present to the doctor in a variety of ways. For example, eye disease may cause painful eyes or blurred vision, lung involvement may result in shortness of breath, and pain and mobility problems may occur with joint and muscle disease. The disease can develop gradually or suddenly. Some present with a ‘flu-like' illness with joint pains, fever and a painful red ‘lumpy' rash that usually affects the shins. Swollen glands (or lymph nodes) are often demonstrated on the chest X-ray of these patients. This particular group of symptoms and X-ray findings are collectively known as Löfgren's syndrome. Other patients have no symptoms at all and abnormalities are often only detected on chest X-rays performed as part of routine medical examinations. General complaints, such as tiredness and low energy, are common.
How is it diagnosed?
Making a diagnosis can be difficult because the most of the symptoms can occur in a variety of other diseases and are not specific to sarcoidosis. It is therefore possible that it may occasionally be mistaken for other diseases, and vice versa. Although typical combinations of general complaints often raise the possibility of sarcoidosis, the diagnosis is usually confirmed following examination and investigations.
What investigations will I require?
Identification of non-caseating granulomas in biopsies (tissue samples) from the affected tissue or organ is extremely helpful in making the diagnosis. Although biopsies may be taken from any organ, skin and lung biopsies are most frequently performed. Non-caseating granulomas can be found in other diseases but their presence in tissue taken from a patient who has symptoms, examination findings or investigations suggestive of sarcoidosis, is generally sufficient to confirm the diagnosis.
However, to decide if biopsies are necessary, other less invasive tests are performed first. These usually include simple blood tests, a 24-hour urine collection, a chest X-ray, lung function tests, an eye examination and a gallium scan. One blood test measures the level of angiotensin-converting enzyme (ACE) in the blood. Granulomas are known to produce ACE and levels of this enzyme are frequently elevated in sarcoidosis, particularly if the disease is active. It can therefore be helpful in monitoring the disease activity. The amount of calcium in the blood or urine may also be elevated in sarcoidosis, so blood and urine testing is routinely performed. Chest X-rays can show whether the lungs or the lymph nodes in the chest are affected, and lung function tests tell us how well the lungs are actually working. Most patients will also have a gallium scan. This is a whole body scan that detects the parts of the body affected by inflammation.
How is it treated?
The main aims of treatment in sarcoidosis are: symptomatic relief, suppression of active disease, prevention of disease progression and support of damaged organs. These are usually achieved with drug therapy, but some patients do not require any treatment at all. The patient's immune system is responsible for much of the tissue damage in sarcoidosis and the majority of the drugs used to treat this condition act by suppressing the patient's immune system in some way.
The most frequently used drugs in sarcoidosis are steroids (usually prednisolone), either alone or in combination with other drugs. Sarcoidosis responds extremely well to steroids. However, they have a number of side effects, such as weight gain, easy bruising and osteoporosis (or bone thinning). Patients are monitored to detect osteoporosis, and those considered to be at high risk of developing this side effect are usually offered medication to prevent it. Most patients are started on a moderate to high dose (30-60mg/day) of steroid, although the dose generally depends on the disease severity and the part of the body affected. The steroids are gradually reduced over the next few months, with the aim of stopping treatment in about one year.
However, some patients deteriorate when the steroids are reduced below a certain dose and it is sometimes necessary to introduce other drugs before the steroid dose can be decreased. These drugs are sometimes referred to as ‘steroid-sparing agents'. They include hydroxychloroquine, methotrexate, sulphasalazine, cyclosporin, cyclophosphamide and thalidomide. During the course of a patient's disease, it is sometimes necessary to switch between the drugs or use them in combination. Unfortunately, they also have side effects and patients therefore need to be regularly monitored.
What should I expect in the future?
We are unable to predict the course of sarcoidosis in each individual patient, but it is thought that the disease resolves within 2-3 years in approximately two-thirds of patients. In other patients, the condition is more chronic and the symptoms come and go throughout their life. However, the majority of patients with sarcoidosis lead a relatively normal life.
Sarcoidosis and the Royal Free Hospital
The Royal Free Hospital cares for a large number of patients with sarcoidosis. The majority of our patients are from the United Kingdom , but we treat patients from countries all over the world. The hospital has a dedicated outpatient sarcoidosis clinic and also provides all the facilities required for the care and assessment of patients in whom admission to hospital is required. In addition, an active sarcoidosis research program is also in operation at the hospital, which facilitates an up-to-date approach to patient care. The Royal Free Hospital also has close links with the Royal Brompton Hospital and the National Sarcoidosis Association.
Any correspondence regarding the sarcoidosis department at the Royal Free Hospital should be directed to:
Dr H Beynon (Consultant Physician and Rheumatologist)
Department of Rheumatology
The Royal Free Hospital
Pond Street
London NW3 2QG