If you’re concerned that you or someone you love might have lyme disease, then you’re likely weighing your options regarding blood tests to confirm that diagnosis. The medical community has some variance when it comes to their advice regarding a lyme disease test – some say it’s worth knowing, others respond that it’s not as accurate as they would like and can result in a false positive. Below you’ll see a breakdown of the most common form of test they run on someone suspected to have lyme disease.
Lyme Disease Testing
Lyme disease is recognized as a clinical diagnosis that is supported by diagnostic tests. However, a patient may have Lyme disease but not test positive on a particular test. Many different tests may be ordered for an individual patient for two reasons. First, the internist will want to rule out other possible causes of the persistent symptoms that may not yet have been considered. Second, the physician will want to determine whether the constellation of findings in this particular patient is similar to that which one finds with other patients who have Lyme disease.
The two tests most commonly used when checking for Lyme disease are the ELISA and the Western blot. These tests detect antibodies present in the patient’s blood that have been triggered by infection with the spirochete, B.burgdorferi. These antibodies however do not necessarily tell us whether or not the infection is still present, as the human immune response continues to “recall” the previous infection for many months to years and thus continues to produce the Bb-specific antibodies. The indirect nature of these tests is thus problematic as it does not reveal whether or not infection continues to persist in the patient.
The Enzyme Linked Immunosorbent Assay (ELISA) is inexpensive, automated, and widely used as a screening test for Lyme disease. A single number is reported that reveals the relative quantity of antibodies in the patient’s serum against the agent of Lyme disease. Most commonly, the whole cell sonicate of Bb is used for the ELISA assay, but this assay can result in both false negatives and false positive. More recently, the C6 Peptide ELISA has been used as a screening assay as it has specificity rates of 90-100%. Unfortunately, the sensitivity of the ELISA and the IFA (immunoflourescence assay) vary considerably, with estimates ranging from 55% to 90% depending upon the clinical manifestations and duration of infection.
– via www.columbia-lyme.org
Wanting a definitive answer to your symptoms makes total sense, and you should always heed your doctor’s advice about when is the right time to perform any given test. But knowing all of the facts is important as well, and in the case of lyme disease blood test, there is the danger of a false positive leading to more worry and confusion about your condition, rather than less.
The Blood Tests Can Have False Positives
The blood tests can trigger false positives, suggesting that you have the disease when you really don’t. This can happen in up to one out of four tests.
This can lead to unnecessary treatment with antibiotics. These drugs are usually safe, but they sometimes cause side effects, such as nausea, vomiting, diarrhea, and increased sensitivity of the skin to sunlight. In rare cases, they can even cause dangerous allergic reactions.
Using too many antibiotics can also lead to the growth of drug-resistant bacteria. This means that bacteria in your body may get stronger and more difficult to treat in the future.
A false positive can also lead to more unneeded blood tests, urine tests, x-rays, and doctor visits.
If you have a false positive, you may not get treated for the real cause of your pain. For example, rheumatoid arthritis is a disease that causes joint pain. It can lead to permanent and severe joint damage if you do not start taking the right medicines as early as possible.
– via www.choosingwisely.org
Did you decide to go forward with a blood test to confirm your diagnosis? Or does your doctor consider that particular test to be unreliable?