How to manage
who needs coeliac disease confirmed
If a patient has been avoiding gluten because of symptoms caused and requests a test for coeliac disease, how long will they have to resume eating gluten for serological tests to become positive?
The period of time needed on resuming gluten in the diet and the amount of gluten necessary to provoke serological immune response in susceptible individuals varies with each individual and is dependent upon several factors. Studies suggest one factor is the amount of gluten eaten and another is the genetic predisposition of the individual.
Studies have shown that 0.3g/kg body weight/day of single gluten challenge causes immunological changes in the lining of the small intestine in paediatric patients on a gluten-free diet within two weeks.
However, other studies suggest the serological response is much slower with a large majority of patients developing a positive response in three months.
Based on this evidence many clinicians recommend eating the equivalent of about six slices of bread every day for at least three months prior to the serological tests.
However, if somebody experiences symptoms and feels unwell during this gluten challenge, I would consider carrying out serological tests earlier as well. If I obtained a positive result I would refer to hospital for an endoscopy and duodenal biopsy to confirm diagnosis of coeliac disease. Home test serological kits for coeliac disease are now available and being promoted to the public.
Evidence suggests these tests are as accurate as hospital laboratory tests. Given the one in 100 positive serology rates in the general population, it is likely we will all be seeing patients requesting advice on interpretation of these results.
Sohail Butt is a GP in Ashford, Middlesex, with an interest in coeliac disease