How often must a negative test be repeated in suspect individuals? (This question has two aspects: for an individual with existing symptoms, and for a sibling of a known celiac.)**

Vijay Kumar, M.D., Research Associate Professor at the University of Buffalo and President and Director of IMMCO Diagnostics: If the test is negative and there is a strong suspicion of celiac disease, it must be repeated after several weeks (3-4 weeks), especially after a high gluten intake. We did a study of two cases with DH who were serologically negative. However, a gluten challenge 1g/Kg body wt/day resulted in positive serology; the results became normal on a gluten free diet.

If you are a relative of a celiac disease patient and are on a regular diet and the serology performed by an experienced laboratory is negative then there may not be any need for retesting until and unless clinically justified.

Celiac.com Sponsor (A12):
Karoly Horvath, M.D., Ph.D., Associate Professor of Pediatrics; Director, Peds GI & Nutrition Laboratory; University of Maryland at Baltimore: There is no rule for it. If a family member with previous negative tests experiences any gastrointestinal symptoms associated with celiac disease, he/she should undergo serological testing as soon as possible. It is well known that up to 15% of the family members of a patient with celiac disease may have the asymptomatic (latent or silent) form of celiac disease, although they have positive serological tests and have the pathological changes in the upper part of the small intestine. It is also evident that there are at least three developmental stages of mucosal lesions (Marsh MN. Gastroenterology 1992;102:330-354) and celiac disease may manifest at each period of life. That is why we recommend a repeat test every 2-3 years in first degree relatives of celiac patients.