If antibody tests and/or symptoms suggest celiac disease, a physician should establish the diagnosis by obtaining tiny pieces of tissue from the small intestine to check for damage to the villi. This is done via endoscopic biopsy. Under sedation, the physician eases a long, thin tube called an endoscope through the mouth and stomach into… Read more »(Updated .)
Keyword: false negative
Are biopsies of the small intestine conclusive?
Generally, antibody blood tests and biopsies are sensitive and specific enough to clearly diagnosis celiac disease. However, because no test is perfect, a firm diagnosis should include antibody blood screening, biopsies and response to a gluten-free diet. Although biopsies are the standard for diagnosis, periodically they do not lead to a clear diagnosis. Many factors… Read more »(Updated .)
Is it possible to have a negative blood test, but a positive biopsy?
While rare, it is possible to have a negative blood test and still have celiac disease. tTG sensitivity is approximately 98%, which means that 2% of all celiacs may have a normal tTG level. Sometimes tTG antibodies are not produced enough to show up in the blood stream and can only be detected in the… Read more »(Updated .)
In blood tests, are false positives less common than false negatives?
Even though blood tests are quite accurate, they are falsely positive 1-3% of the time (i.e., being positive without the person having celiac) and, although less commonly, falsely negative 1-2% of the time (i.e., being normal when a person actually has celiac).(Updated .)