Histologically nonresponsive coeliac disease (NRCD) is a potentially serious condition diagnosed during the follow-up of celiac disease when patients have persistent villous atrophy despite following a gluten-free diet (GFD).
Current assessments of recovery are limited to invasive and costly serial duodenal biopsies.
Dr Daugherty and colleagues from California, USA identified antibody biomarkers for celiac disease patients that do not respond to traditional therapy.
Bacterial display peptide libraries were screened by flow cytometry to identify epitopes specifically recognised by antibodies from patients with NRCD, but not by antibodies from responsive celiac disease patients.
|anti-dGP IgG titre discriminated between NRCD and responsive celiac disease patients with 87% sensitivity |
|Alimentary Pharmacology & Therapeutics|
Deamidated gliadin was confirmed to be the antigen mimicked by library peptides using ELISA with sera from NRCD and responsive celiac disease patients on a strict GFD for at least 1 year.
The team observed that the dominant consensus epitope sequence identified by unbiased library screening QPxx(A/P)FP(E/D) was highly similar to reported deamidated gliadin peptide (dGP) B-cell epitopes.
Measurement of anti-dGP IgG titre by ELISA discriminated between NRCD and responsive celiac disease patients with 87% sensitivity and 89% specificity.
The team found that dGP antibody titre correlated with the severity of mucosal damage indicating that IgG dGP titres may be useful to monitor small intestinal mucosal recovery on a GFD.
Dr Daugherty's team concludes, "The finding of increased levels of anti-dGP IgG antibodies in celiac disease patients on strict GFDs effectively identifies patients with NRCD."
"Finally, anti-dGP IgG assays may be useful to monitor mucosal damage and histological improvement in celiac disease patients on a strict GFD."