Sorbitol H2-breath test versus anti-endomysium antibodies to assess histological recovery after gluten-free diet in coeliac disease

Background. Gluten-free diet plays a key role in treatment of coeliac disease, but it is difficult to evaluate its effect on improvement of villous architecture using sensitive non-invasive tests.Aims. To compare sorbitol H₂-Breath Test with antiendomysial antibodies in the follow-up of coeliac disease to detect histological recovery.Methods. A total of 38 consecutive patients with coeliac disease were studied. All underwent Sorbitol H₂-Breath Test, antiendomysial and oesophagogastroduodenoscopy with multiple bioptic samples before diet and then 6, 12 and 18 months after gluten-free diet. Expiratory samples were collected before patients drank the test solution (5 g sorbitol in 150 ml tap water) and thereafter every 30 min for 4 hours. An increase in H₂ concentration of ≥20 ppm, above fasting baseline was considered positive for sorbitol malabsorption. Antiendomysial antibodies were evaluated by the indirect immunofluorescent method.Results. Antiendomysial antibodies were positive in 32/38 patients before gluten-free diet (84.21%), while they were positive in 20/34 (54.82%), 2/16 (12.5916) and 0/2 (0%) cases after 6, 12 and 18 months of gluten-free diet, respectively, no correlation being found with improvement of histological lesions (p=ns). As far as concerns sorbitol H₂-Breath Test, maximal cut-off value (in ppm) decreased progressively and parallel to histological recovery during follow-up. Indeed, it decreased from a mean 63 ppm before diet to 35, 19 and 12 ppm, after 6, 12 and 18 months of gluten-free diet, with a statistical difference being found before and after p<0.001]. Likewise, the peak value (in minutes) appeared progressively later during follow-up, parallel to histological recovery. In fact, it appeared at a mean of 119 minutes before gluten-free diet, while it appears at a mean of 164, 195 and 219 minutes after 6, 12 and 18 months on glutenfree diet. A statistical difference before and after start of gluten-free diet was found also in this case (p<0.001). Conclusions. Sorbitol H2-Breath Test is better than antiendomysial antibodies in revealing histological recovery in the follow-up of coeliac patients after the start of gluten-free diet due to its good correlation with histological damage. Moreover, it also appears to be able to detect dietary mistakes of the patients on gluten-free diet.