Celiac.com 08/16/2012 - Tests for blood antibodies against native gliadin (anti-nGli) are still often assumed to perform better in the diagnosis of celiac disease in young children than tests for antibodies to deamidated gliadin (anti-dGli), tissue transglutaminase (anti-tTG), and endomysium (EmA).
A team of researchers recently set out to determine whether testing IgG and IgA antibodies Against native gliadin was best for diagnosing celiac disease in children under 2-years old. Specifically they wanted to compare the performance of assays for anti-nGli, anti-dGli, anti-tTG, and EmA in this age group.
They are affiliated with the University Children's Hospital, the Children's Hospital of the Clinical Centre, "Sankt Georg," and the Institute of Laboratory Medicine, Clinical Chemistry and Molecular Diagnostics at University Hospital in Leipzig, Germany; with the Department Laboratory Medicine of University Hospital in Leuven, Belgium, the University Children's Hospital in Tübingen, Germany, the University Children's Hospital in Graz, Austria, the University Children's Hospital in Giessen, Germany, the Department of Paediatrics at Leiden University Medical Centre in Leiden, The Netherlands, and with EUROIMMUN Medizinische Labordiagnostika GmbH in Lübeck, Germany.
For their study, they conducted a retrospective analysis of 184 children. The study group included 42 children with celiac disease under normal diet, and a control group of 142 children up to 2 years of age.
The team measured immunoglobulin (Ig) A- and IgG-anti-dGli, IgA- and IgG-anti-nGli, IgA- and IgG-anti-tTG, and IgA-EmA in blood samples. They calculated areas under receiver operating characteristics curves, sensitivities, specificities, positive and negative predictive values, positive and negative likelihood ratios, as well as diagnostic odds ratios.
When all the data was complete, they found that only tests for IgG-anti-dGli, IgA-anti-tTG, and IgA-EmA had high specificity (≥0.96) connected with high sensitivity (≥0.86), with high positive predictive values (≥0.52 and ≥0.69 at pretest probabilities of 0.05 and 0.1, respectively) and negative predictive values (≥0.99 and ≥0.98 at pretest probabilities of 0.05 and 0.1, respectively).
These tests also showed high positive likelihood ratio (≥24) at low negative likelihood ratio (≤0.15) and high diagnostic odds ratios (≥136).
From their data, the team concluded that using anti-nGli tests to diagnose celiac disease in young children was not helpful. They maintain that IgA-anti-tTG, IgA-EmA, and IgG-anti-dGli provided much more reliable results than anti-nGli in diagnosing celiac disease in young children.