Confused - False Positive in Celiac Disease Pre-Diagnosis, Testing & Symptoms Posted July 22, 2009 · Report to Admin I have done a lot of research on false positives and weak positives in the last few months because my 9 year old son's tTg IGA was 4.3 on a scale where 0-4 negative, 4-10 weak positive. What I found indicates that you are much more likely to have a false negative than a false positive. According to most of what I read, even if not all the tests are positive they should still do an endoscopy to check for damage especially if they are having symptoms such as your son is. Did they do the endoscopy yet? Some of the things that could cause a false positive on the tTg are cirrhosis of the liver, diabetes or heart failure but this is very rare. Given his symptoms it seems much more likely he has celiac. I hope they are able to figure it out soon so your son can start healing. My son is seeing a specialist next week. He was tested due to family history and not really sick at the time but in the last few months he has started being tired all the time and complaining of stomach aches. He has occasional bathroom issues and has become whinier than usual. I'm hoping the doctor will agree to do the endoscopy so we can see if he has it or not.