Immune phenotype of children with newly diagnosed and gluten-free diet-treated celiac disease.

Background: Recent data suggest the involvement of both the adaptive and the innate immune system in celiac disease (CD). However, little is known about the immune phenotype of children with CD and its alteration upon dietary intervention.

Aims: We characterized the prevalence of major interacting members of the adaptive and innate immune system in peripheral blood of newly diagnosed children with CD and tested its alteration with the improvement of clinical signs after the introduction of gluten-free diet (GFD).

Methods: Peripheral blood was taken from ten children with biopsy-proven CD at the time of diagnosis and after the resolution of clinical symptoms following GFD. As controls, 15 children with functional abdominal pain were enrolled. The prevalence of the cells of adaptive and innate immunity was measured with labeled antibodies against surface markers and intracellular FoxP3 using a flow cytometer.

Results: Patients with CD were found to have lower T helper, Th1 and natural killer (NK), NKT and invariant NKT cell prevalence and with higher prevalence of activated CD4(+) cells, myeloid dendritic cells (DC) and Toll-like receptor (TLR) 2 and TLR-4 positive DCs and monocytes compared to controls. After resolution of symptoms on GFD, the majority of these changes normalized, although the prevalence of NK and NKT cell, DC and TLR-2 expressing DCs and monocytes remained abnormal.

Conclusions: The immune phenotype in childhood CD indicates the implication of both adaptive and innate immune system. The normalization of immune abnormalities occurs on GFD, but the kinetics of this process probably differs among different cell types.