Is it really possible to have celiac with practically negative antibodies?

Hi. Our 10 year old girl has many tummy problems the past 4 months. Every single test was negative other than grensen limit of one of the celiac IgA antibodies. Because she has been vomiting and having pains for months now, and all other tests including barium and nucleotide test were normal, they decided to go ahead with a gastroscopy and biopsy too. This is scheduled in two months. Meantime she hasn’t been to school for 4 months, she has been losing weight and having awful pains mainly at night and she is still vomiting daily. Is it really possible to have celiac with negative practically antibodies? To mention that when the antibodies were done she has been vomiting already for 12 days up to 9 times per day so she wasn’t ready getting much food into her then. Could all that vomiting lead to antibodies being negative and should we repeat them? How possible is it actually to have celiac disease with negative/grensen antibodies? Part of me wants to put her on a trial gluten free diet already. Seems cruel to wait two more months when she is so sick and can’t go to school. Thank you for any insight.

Only active celiac disease can be diagnosed and that requires enough gluten (minimum 2 slices of bread pro day) in a long enough period prior to being tested (minimum 6 weeks). If she vomits as much as you indicate, then she may not consume enough gluten to keep the celiac disease active enough to be diagnosed. But just her vomiting and weight loss is enough to warrant a gastro-duodonoscopic examination with biopsies from the stomach and duodenum. If she starts a gluten free diet, then her putative celiac disease may not be diagnosed, but any other condition responsible for her symptoms may still be diagnosed. If she becomes better on GFD and her gastro-duodenoscopy and biopsies comes back as normal/unspecific inflammation, then you may have to reintroduce gluten in order to get her putative celiac disease reactivated and diagnosed. Is there anything else she may be allergic/intolerant to, any other food she may vomit from? Write a diary of which food she consume and what reactions she has to find any pattern.