Il ruolo degli anticorpi anti peptidi deamidati di gliadina nell'iter diagnostico della malattia celiaca

Celiac disease (CD) is an immune-mediated enteropathy triggered by the ingestion of wheat gliadins and other correlated prolamines, in genetically susceptible individuals. CD is characterized for a variable combination of gluten-dependent clinical demonstrations, specific antibodies as IgA anti-endomysial antibodies (EMA), IgA antibodies to tissue transglutaminase (tTG) and the antibodies to deamidated gliadin peptides (DPG), genotypes HLA DQ2 or DQ8 and enteropathy. (Guidelines ESPGHAN 2011) Until recently the geographical distribution of celiac disease was mostly restricted to Europe and other developed countries, such as the USA, Canada, Australia. New epidemiological studies have provided evidence that this disorder is also common in other parts of the world including the Asian continent. CD prevalence is increased in at-risk conditions such as family history of celiac disease, autoimmune diseases, and some genetic syndromes. Recent studies have demonstrated that deamidated gliadin peptides are more specific CD B-cell epitopes than native peptides; antibodies directed against deamidated peptides were identified and more recently a new ELISA for IgG and IgA antibodies to deamidated gliadin peptides (DPG-AGA) has been developed. Many studies described a middle sensibility of these antibodies for CD to 92% for IgA and to 91% for IgG and, more interesting an elevated (99%) specificity for DPG AGA IgG. Our study describes the experience of Pediatric Gastroenterology of Parma, comparing this new antibodies with the traditional (tTG IgA, EMA, AGA IgA) tests in two groups of patients aged between 0 and 18 years. To the first group belong 41 patients studied for suspected celiac disease, the second group includes 12 patients in follow-up to previously diagnosed with celiac disease. Our results demonstrate, in agreement with literature data, which this new test (DPG-AGA) has a diagnostic accuracy greater than traditional antibodies and that, despite having a lower sensitivity than the endomysial antibodies (EMA) and the anti-tissue transglutaminase (tTG IgA), has a significantly higher specificity. Particularly the deimidated gliadin antibodies IgG (AGA-IgG DPG) may be used as serological markers of celiac disease especially for patients with less than 2 years and in cases of disease associated with IgA deficiency. The associated antitranglutaminasi tissue research (tTG IgA) and anti-deamidated peptide of gliadin (DPG-AGA IgG) has proved significant in diagnostic screening phase of disease to correctly identify the affections. Moreover deamidated gliadin peptides antibodies (DPG-AGA IgG) can be helpful in follow-up of celiac disease, since the persistence of this antibody in patients with gluten-free diet indicates low compliance to the diet itself and lack of improvement of intestinal mucosal injury.