Antibodies against synthetic deamidated gliadin peptides for celiac disease diagnosis and follow-up in children.
BACKGROUND
AGA IgA II and AGA IgG II have recently been suggested as reliable tools for celiac disease (CD) diagnosis. We compared their utility for diagnosis and monitoring CD in children with that of tTG IgA, an established CD marker.


METHODS
We studied a cohort of 161 CD and 129 control children in whom CD was histologically confirmed or ruled out. We followed 37 children with CD on a gluten-free diet for 12-84 months. In fasting sera, we measured AGA IgA II, AGA IgG II, and tTG IgA using ELISAs.


RESULTS
The best sensitivity (92.5%), specificity (97.6%), positive predictive value (98%), and negative predictive value (91.2%) were obtained using tTG IgA. AGA IgG II correctly identified 3 of 3 children with CD with total IgA deficiency who had negative AGA IgA II and tTG IgA results. In children <2 years old without total IgA deficiency, AGA IgG II and tTG IgA performed equally well (sensitivity 96.4% and specificity 100%). AGA IgA II, AGA IgG II, and tTG IgA concentrations diminished significantly (P < 0.0001) after 1 year of a gluten-free diet, reaching values below the cutoff in 87%, 70%, and 51% of cases, respectively.


CONCLUSIONS
The best available index for diagnosing CD in children was tTG IgA. In infants <2 years old, AGA IgG II performed as well as tTG IgA in cases without total IgA deficiency and allowed detection of CD when total IgA was <0.06 g/L. Gluten-free diet monitoring can be achieved using any of the studied serum markers.
Basso
Daniela
D
Department of Laboratory Medicine, University of Padova, Italy.
Guariso
Graziella
G
Fogar
Paola
P
Meneghel
Alessandra
A
Zambon
Carlo-Federico
CF
Navaglia
Filippo
F
Greco
Eliana
E
Schiavon
Stefania
S
Rugge
Massimo
M
Plebani
Mario
M
D000293:Adolescent; D000906:Antibodies / Q000097:blood* / Q000276:immunology; D015415:Biomarkers / Q000097:blood; D002446:Celiac Disease / Q000097:blood* / Q000175:diagnosis* / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005500:Follow-Up Studies; D005903:Gliadin / Q000097:blood* / Q000276:immunology; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood / Q000276:immunology; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology; D007223:Infant; D008297:Male; D010455:Peptides / Q000097:blood* / Q000276:immunology; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
D000906:Antibodies; D015415:Biomarkers; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D010455:Peptides; D005903:Gliadin