Predicción de lesión histológica intestinal en pacientes pediátricos con enfermedad celíaca

Abstract

IntroductionSerological markers are of great interest in coeliac disease (CD), although intestinal biopsy is still the gold standard for establishing the diagnosis. Tissue transglutaminase IgA antibodies (AATGt-IgA) and antiendomysial antibodies IgA (AAE-IgA) are closely correlated to intestinal damage observed in biopsies. Villous atrophy (Marsh 3) plays a major role in CD diagnosis. Marsh 2 stage (crypt hyperplasia) as a CD marker is still under debate. ObjectiveTo ascertain an AATGt-IgA level that corresponds to a positive predictive value (PPV) of 100% for a histological CD diagnosis. Material and methodsA series of 120 patients younger than 14 years, non- IgA deficient, who underwent an intestinal biopsy and were positive for both serological markers (AATGt-IgA and AAE-IgA). For AATGt-IgA, according to the manufacturer's recommendations, a value greater than 16 IU/mL is considered as a positive value. The PPV of AATGt was determined for different cut-off points. ResultsThe histological findings distribution is directly correlated to the AATGt-IgA cut-off point. When the cut-off point is set above 7.5-10.6 times the commercial reference value, there is a 2.1% of Marsh 2 lessions and 93.4% of Marsh 3; above 10.6 times the reference value, all biopsies where Marsh 3 (100%). The PPV that considers Marsh 3 is (93.4%). The PPV, for considering Marsh 3 is low (55%) when AATGt-IgA serology is positive with levels between 16 and 67IU/ml (1-4.2 times the cut-off point) and a higher value (92%) for concentrations between 68 and 118IU/ml (4.3-7.4 times) and for cases with 69-170IU/ml (7.5-10.6 times); above 170 IU/ml (>10.6 times) PPV is 100%. ConclusionThe use of values higher than the recommended cut-off point must logically improve specificity and PPV. In 31.6% patients positive for AATGt-IgA and AAE-IgA (38/120) it would have been possible to diagnose the disease without intestinal biopsy as of the PPV was 100%. It is not possible to standardise results as there are different commercial kits with variable cut-off points, so we must be cautious when setting recommendations based on AATGt-IgA.