How is SLE diagnosed?
The diagnosis of SLE is made based on a combination of symptoms, signs and test results and after other illnesses have been ruled out. There is no single disease symptom, sign or test which, alone, will give a diagnosis of SLE. Given the thousand faces of SLE, and because symptoms such as fatigue, weight loss or fever may be the only clues at the beginning, the diagnosis may be especially difficult. However, physicians are more aware of this situation and the result is shorter delays in diagnosis and the recognition of milder forms of lupus. Four, and sometimes five, steps are needed to establish the diagnosis. The first is a thorough review of the person’s symptoms. The second is a detailed physical examination. The third is performance of a whole battery of tests. Remember that several of the 11 SLE criteria consist of abnormal laboratory tests and it is just not possible to avoid doing all those tests (and taking all that blood) because it is not known what tests will be abnormal in
SLE may be hard to diagnose and is often mistaken for other diseases. For this reason, lupus has often been called the “great imitator.” No single test can tell if a person has lupus. There are many ways to diagnose SLE: • Medical history. Give your health care provider (HCP) a complete, accurate medical history. This information, along with a physical exam and special tests, helps your HCP rule out other diseases that can be confused with lupus. • Symptoms. Having 4 (or more) of the 11 symptoms of lupus, as defined by the American College of Rheumatology. For a list of these symptoms, go to www.rheumatology.org/research/classification/sle.html • Lab tests. The Antinuclear antibody (ANA) test is a commonly used test. An antibody is a chemical the body makes to fight off infections. The test looks for the strength of your antibodies. Most people with lupus test positive for ANA.
Physicians have to gather information from a variety of sources- past medical history, lab tests & current symptoms. They use a list of 11 criteria to help diagnose SLE. Generally, a person needs to satisfy at least 4 out of the 11 criteria before a diagnosis can be made. (see the diagnosis page for more info.
If your symptoms suggest SLE then your doctor will usually do some blood tests. Most people with SLE have an antibody called antinuclear antibody in their blood. (Antibodies are small proteins that are part of the immune system.) Another antibody called anti-doubled stranded DNA (dsDNA) is a often present in people with SLE. Various other antibodies are also associated with SLE. However, they can also occur in perfectly well people who do not have SLE. However, typical symptoms combined with high levels of certain antibodies usually indicate that you have developed SLE. Once SLE is diagnosed, you will normally be advised to have regular checks and tests. For example, regular blood tests to check for anaemia and urine tests to check for kidney problems. A blood test to measure a blood chemical called ‘complement’ (another part of the immune system) can assess the activity of the disease. The level of this chemical reflects how ‘active’ the disease is. Other tests including scans and X-r
