Practical aspects of differential diagnosis of coeliac disease and gluten hypersensitivity
The objective. To determine the frequency of the pathological alleles DQ2 and DQ8 in children diagnosed with coeliac disease and the possibility of taking them into consideration in differential diagnosis of forms of gluten intolerance.
Patients and methods. The examination included 37 children aged 1 to 17 years who were previously diagnosed with coeliac disease and followed a gluten-free diet for 6 months to 16 years, and also 3 sibs. HLA–DQ2 and HLA–DQ8 haplotypes were determined. In the absence of these heterodimers, rechallenging children was recommended, before and after which tissue transglutaminase Ig A, G and endomysial antibodies were determined and morphological examination of small intestinal bioptates was performed.
Results. The genetic markers of coeliac disease were found in 25 (67.6%) children: the DQ2 allele was found in 51.4%, DQ8 – in 16.2%, and they were not found in 25 (32.4%) children. Gluten rechallenge was performed in 7 of 12 children. Its results permitted to rule out coeliac disease and interpret the symptoms observed when making a diagnosis as gluten hypersensitivity in 6 children and allergy to grains in one child. In five patients with the absence of DQ2 / DQ8 no rechallenge was performed due to parental refusal but their symptoms were also assessed as gluten sensitivity. Therefore, the latter was found in 29.7%. In 2 of 3 sibs DQ2 was found, as in their brothers, no clinical symptoms were noted.
Conclusion. Among children with previously diagnosed coeliac disease, in 29.7% of patients gluten intolerance took the form of gluten sensitivity. In the Voronezh region, children with coeliac disease have the prevalent haplotype DQ2 (in 76%), 24% have HLA–DQ8.
Key words: genetic markers, gluten hypersensitivity, children, gluten intolerance, coeliac disease