1. Monitoring patients with celiac disease on gluten free diet: different outcomes comparing three tissue transglutaminase IgA assays
- Author
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Mulder, A H Leontine, Castelijn, Daan A R, van der Pol, Pieter, Vermeer, Marloes, Hollander, Jolien C, Kuiper, Tietie, Bijnens, Caroline, Bontkes, Hetty J, Damoiseaux, Jan, Mulder, A H Leontine, Castelijn, Daan A R, van der Pol, Pieter, Vermeer, Marloes, Hollander, Jolien C, Kuiper, Tietie, Bijnens, Caroline, Bontkes, Hetty J, and Damoiseaux, Jan
- Abstract
Objectives: Tissue transglutaminase (tTG) IgA antibodies are a hallmark for celiac disease (CD). In CD patients on gluten free diet (GFD) these antibodies are transient. Few studies are available comparing the tTG-IgA assay characteristics for monitoring response to GFD. Since discrepant results were reported in patients on GFD after switching tTG-IgA assays, we conducted a retrospective observational study to monitor GFD response using three different tTG-IgA assays. Methods: Diagnostic samples from 44 adults and 17 children with CD were included. Of most patients two follow-up samples after introduction of GFD were available. In all samples tTG-IgA were assessed using one fluorochrome-enzyme immuno-assay (FEIA) and two chemiluminescence immuno-assays (CLIA) and intestinal fatty acid binding protein (i-FABP) as surrogate marker for intestinal epithelial damage was measured. Results: Using CLIA assays, normalization of antibody levels was delayed compared to FEIA (p<0.001). Of all samples taken after at least 6months on GFD with elevated i-FABP indicating intestinal epithelial damage, 40% had positive tTG-IgA according to the FEIA, 85 and 90% according to the two CLIA. Conclusions: Normalization of tTG-IgA in patients on GFD depends on the assay used. Both CLIA appear to be more sensitive in detecting suboptimal treatment response in CD-indicated by elevated i-FABP - when applying the manufacturer's recommended cut-off for the diagnosis of CD.
- Published
- 2024