After a celiac test has shown positive results you may still have doubts whether it’s celiac disease or can a positive celiac blood test mean something else? Let’s explore this issue in more detail.
People with celiac disease who eat gluten have higher than normal levels of certain antibodies in their blood. These antibodies are produced by the immune system as it perceives gluten (proteins found in wheat, rye, and barley) as a threat. You must be on a gluten-free diet for antibody (blood) testing to be accurate.
The tTG-IgA test will be positive in about 98% of celiac patients who are on a diet containing gluten. This is called the sensitivity of the test.
There is still a small risk of a false-positive test result. There we are again with our question: can a positive celiac blood test mean something else? The answer is yes, especially for people with associated autoimmune disorders such as type 1 diabetes, autoimmune liver disease, Hashimoto’s thyroiditis, psoriatic or rheumatoid arthritis, and heart failure who do not have celiac disease.
There are other antibody tests available to double-check for potential false positives or false negatives, but due to the potential false antibody test results, a biopsy of the small intestine is the only most accurate way to diagnose celiac disease.
At the same time, given the high predictive value of a positive serological test result (> 95%), increased TGA-IgA 10 norms the upper limit of the reference value and a positive test for EMA-IgA in a separate blood sample reduce the risk of false-positive results. How consequently, the diagnosis of celiac disease can be made without a biopsy of the small intestine.
The endomysial IgA antibody (EMA) test is generally for people who have difficulty diagnosing celiac disease. It is not as sensitive as the tTG-IgA test and is more expensive.
According to the interpretation of the results of Testnord Blood Test Iron Levels, you might get three outcomes.
The first one is a positive result. The result means that the ferritin concentration in blood is normal and that there is no potential iron deficiency. A positive result means that ferritin concentration in blood is lower than 20 ng/mL and a possible iron deficiency. Ferritin is a protein that binds and stores most of the iron in the body. Neither only a minor part of the ferritin is found in blood, it corresponds to the amount of iron stored in the body.
Second – negative and means that the ferritin concentration in blood is too low. Iron reserves are insufficient. You should consult a doctor because it may be an iron deficiency anemia. f the result is negative, it means that the ferritin level is higher than 20 ng/mL and is within the norm. However, if the symptoms persist, it is recommended to consult a doctor.
Please note that the iron test kits of other producers might have different blood test iron levels.
And the last result is invalid and it arises in the case of wrong utilization or inability of the test kit. Nevertheless, the result can be incorrect if the test gets wet before the test performing or if the quantity of blood dispensed in the sample well is not sufficient. If an invalid result occurs we recommend repeating the test with a new testing device and with fresh blood.
The test is accurate and has been used for more than 10 years by professionals in the field. Evaluation reports show an overall agreement of at least 98% with reference methods. Although this test is reliable, false positive or false negative results could be obtained.
The results of the HSV-1 or HSV-2 test might be different from what you expected. If you don’t experience any symptoms or signs you may wonder what can cause a false positive herpes test.
Many STDs tests can produce false-positive results. There is a bunch of reasons.
- If nfection decreases in the person being tested and the test does not identify enough amount of antibodies.
- If you are at low risk of herpes infection (HSV2).
- If you have only HSV1, you may reacive a false positive for HSV2 infection.
- If you have other viruses from the same family like varicella zoster virus (true for IgM tests).
If you couldn’t explain what can cause a false positive herpes test, then it’s worth visiting your family doctor and seeking some advice.
HSV-1 is usually associated with infection in the oropharyngeal area and eyes, while HSV-2 causes mostly genital and neonatal infections. However, the tissue specificity is not absolute, HSV-2 can be isolated occasionally from the oropharynx and 5-10% of primary genital infections may be caused by HSV-1. The antibody of the IgM class is produced during the first 2-3 weeks of infection with HSV and exists only transiently in most patients. Serologic procedures, which measure the presence of IgM antibodies, help discriminate between primary and recurrent infections since IgM antibodies are rarely found in recurrent infections. If present in a sample, high-affinity IgG antibodies to HSV may interfere with the detection of IgM-specific antibodies. High-affinity IgG antibodies may preferentially bind to HSV-1 antigen leading to false-negative IgM results. Also, rheumatoid factor and antigen-specific IgG may bind to IgG, causing false-positive IgM results. This test is CE marked for professional use. For the first time, if the patient is infected in less than 5 days, with no detected specific antibody, the result will be negative when testing.