Serum and intestinal celiac disease-associated antibodies in children with celiac disease younger than 2 years of age.
OBJECTIVE
In children younger than 2 years of age, a diagnosis of celiac disease (CD) is difficult to make because anti-endomysium (anti-EMA)/anti-tissue transglutaminase 2 (anti-TG2) antibodies are less sensitive than in older children. The aim of our study was to evaluate how many children younger than 2 years of age and diagnosed with CD, were negative for serum anti-TG2 antibodies and to test the hypothesis that in these patients, TG2-specific IgA deposits could instead be present at mucosal level.


METHODS
A total of 104 children younger than 2 years of age and 179 children older than 2 years, all of whom had been diagnosed with CD, were investigated for serum CD-associated antibodies (anti-gliadin [AGA] IgA and IgG, EMA-IgA, anti-TG2-IgA). The presence of intestinal anti-TG2 extracellular IgA deposits was searched by using double immunofluorescence in 56 of the patients younger than 2 years of age and in 40 of those who were older than 2 years.


RESULTS
In children with CD who were younger than 2 years of age, high levels of AGA-IgA were found in 93/104 (89%) and 98/104 (94%) were found of have high levels of AGA-IgG. In children older than the age of 2 years with CD, 120/179 (67%) had high levels of AGA-IgA and 151/179 (84%) had high levels of AGA-IgG. Serum EMA were present in 92/104 (88%) in the younger group and in 176/179 (98%) of the older group. Ninety-one of 104 children (87%) younger and 172/179 (96%) older than 2 years showed high serum levels of anti-TG2. Finally, 41/56 (73%) children younger than 2 years and all of the 40 children (100%) older than 2 years of age showed mucosal anti-TG2-IgA deposits.


CONCLUSIONS
EMA and anti-TG2-antibody measurements show higher sensitivity for the diagnosis of CD in children older than 2 years compared with younger children. The search for mucosal deposits of anti-TG2-IgA does not improve the diagnostic performance.
Maglio
Mariantonia
M
Department of Pediatrics and European Laboratory for the Investigation of Food-Induced Diseases, University Federico II, Naples, Italy.
Tosco
Antonella
A
Paparo
Francesco
F
Auricchio
Renata
R
Granata
Viviana
V
Colicchio
Barbara
B
Indolfi
Viviana
V
Miele
Erasmo
E
Troncone
Riccardo
R
D000293:Adolescent; D000367:Age Factors; D001323:Autoantibodies / Q000097:blood / Q000378:metabolism*; D002446:Celiac Disease / Q000097:blood / Q000175:diagnosis / Q000276:immunology*; D002648:Child; D002675:Child, Preschool; D003238:Connective Tissue / Q000276:immunology*; D019204:GTP-Binding Proteins / Q000276:immunology*; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood / Q000378:metabolism*; D007074:Immunoglobulin G / Q000097:blood / Q000378:metabolism*; D007223:Infant; D007413:Intestinal Mucosa / Q000276:immunology*; D000091345:Protein Glutamine gamma Glutamyltransferase 2; D011503:Transglutaminases / Q000276:immunology*
D001323:Autoantibodies; D007070:Immunoglobulin A; D007074:Immunoglobulin G; C000717608:TGM2 protein, human; D000091345:Protein Glutamine gamma Glutamyltransferase 2; D011503:Transglutaminases; D019204:GTP-Binding Proteins