Novel screening assay performance in pediatric celiac disease and adult dermatitis herpetiformis.

OBJECTIVES

: Several serologic assays are commercially available to aid in the diagnosis of gluten-sensitive enteropathy (GSE). Our objective in this study was to assess the performance of a novel combined antigen-screening assay for GSE.

PATIENTS AND METHODS

: Deidentified sera from 111 pediatric patients suspected of having celiac disease (CD), 130 adults diagnosed with dermatitis herpetiformis (DH), and 77 pediatric and 49 adult normal controls were included in the study. Sera from 10 patients submitted to our laboratory for GSE testing with IgA deficiency and IgG antibodies against 1 or more of the traditional serologic markers associated with GSE were also included. All sera were screened for antibodies (IgA and IgG) against tissue transglutaminase (tTG) and deamidated gliadin peptides (DGP) by enzyme immunoassay (EIA) in a single test well. In addition, all sera were assessed for each individual marker and isotype using separate EIAs.

RESULTS

: The IgA/IgG anti-tTG/DGP EIA screen was 92.6% sensitive and 94.3% specific in pediatric CD and detected 1 patient (Marsh 3c) who was IgA anti-tTG negative; this patient was not IgA deficient (<7.0 mg/dL). All 10 IgA-deficient sera gave positive results by the tTG/DGP EIA screen. Sensitivity and specificity of the tTG/DGP EIA screen in retrospective and prospective DH were 65% and 100% versus 62% and 100%, respectively.

CONCLUSIONS

: The new IgA/IgG anti-tTG/DGP EIA screen was slightly more sensitive than IgA anti-tTG alone in pediatric CD. This novel screening assay may allow the current recommendation of measuring total serum IgA in suspected GSE patients to be eliminated.