Blood serology has been shown to be very useful in the diagnosis of celiac disease, but current research has called in to question its accuracy when looking for intestinal healing in patient follow-up.
After diagnosis, celiac disease (CD) patients must get regular check ups to see if they are responding to their gluten-free diet. Up to 20% of patients have non-responsive celiac disease (NRCD), typically due to accidental gluten exposure. To see if a patient is recovering from CD the doctor can look for any lessening in symptoms, the gut can be directly investigated with a duodenal biopsy, or any antibodies in the blood can be detected using blood serology. In adults, research indicates that serological tests are poor markers for intestinal recovery (see here and here). A recent study looked to investigate whether blood serology is useful for follow up in children with CD.
The study, titled “Can Celiac Serology Alone be Used as a Marker of Duodenal Mucosal Recovery in Children with Celiac Disease on a Gluten-Free Diet?” was published by The American Journal of Gastroenterology on July 29, 2014. The researchers took 150 children with proven CD, and compared their blood serology results with their duodenal biopsy after 12 months or more on a gluten-free diet. The serology included two different tests: one for tissue-transglutaminase (tTG) antibodies and one for deamidated gliadin peptide (DGP) antibodies. The pathologists grading the biopsies used Marsh criteria and were blinded to the results of the serology.
Of the 150 children, 27 had positive serology, 97 had negative serology, and the remaining 26 were inconclusive. None of the 97 children with negative results had Marsh type 3 alterations or worse, however, only 6 of the 27 patients with positive serology had Marsh type 3 or worse changes. The positive predictive value of blood serology in this experiment was very weak, only 22%. However, the negative predictive value was extremely robust at 98%.
Based on the results, the authors concluded that serological tests may be used as an alternative to biopsies for CD follow up in children. The strong negative predictive power of the serology results means that children who test negative can be confident in their intestinal recovery, and save them the trouble of going through multiple follow-up biopsies.
The article “Can Celiac Serology Alone be Used as a Marker of Duodenal Mucosal Recovery in Children with Celiac Disease on a Gluten-Free Diet?” can be found here.