Coeliac disease (CD) is an autoimmune disorder triggered by gluten ingestion in genetically predisposed subjects [
1]. While it is know to affect around 1% of Caucasian schoolchildren, the true prevalence is probably underestimated [
2,
3]. While coeliac disease can occur at any age following gluten introduction in the diet, the onset of symptoms shortly after weaning is uncommon [
4‐
6]. The pathogenesis of the disease depends on the presence of gliadin-reactive CD4+ T cells in the
lamina propria of the small bowel, which recognize gliadin peptides deamidated by tissue transglutaminase and bound to DQ2+ or DQ8+ antigen-presenting cells [
7,
8]. The gliadine-reactive CD4+ T cells enhance an adaptive immune response that leads to intraepithelial and
lamina propria infiltration of inflammatory cells, crypt hyperplasia, and villous atrophy [
9]. Innate immunity also contributes to mucosal damage [
10]. Tissue transglutaminase antibodies (tTG) are directed against the enzyme responsible for the deamidation of gliadin in the
lamina propria. These antibodies perform at a lower sensitivity and specificity in children under 18 months of age compared to older subjects, the earliest tTG seropositivity being reported at the age of 12 months [
11‐
14]. Tests for antibodies to deamidated gliadin peptides (anti-DGPs) have replaced those for anti-gliadin antibodies, as the former show higher specificity [
15]. Immunoglobulin G anti-DGPs are more sensitive than IgA in the diagnosis of CD [
16‐
19]. The combination of IgA anti-tTG and IgG anti-DGP offers the best accuracy for diagnosis of CD at all ages, as it increases the chances of detecting the disease in subjects with IgA deficiency [
17,
20‐
23]. Moreover, the presence of IgG anti-DGPs seems to be the best serologic marker of villous atrophy in the follow up of coeliac patients [
24‐
26]. While in older patients IgA anti-tTG levels generally correlate with the severity of the duodenal lesions according to the Marsh–Oberhuber grading system [
27,
28], in young children high IgG anti-DGP titres are related to severe intestinal damage [
29‐
32].
In this article we present the unusual case of an infant who developed symptoms of CD shortly after weaning. In spite of a complete villous atrophy at biopsy, only serum anti-DGPs were increased, whereas anti-tTG and anti-endomysial antibodies were absent.