HLA-DQB1*02 dose effect on RIA anti-tissue transglutaminase autoantibody levels and clinicopathological expressivity of celiac disease.
OBJECTIVE
Celiac disease is an autoimmune enteropathy caused by gluten ingestion in genetically susceptible individuals. Anti-transglutaminase autoantibody (tTGAb) assay is useful to detect candidates undergoing intestinal biopsy. Our aim was to investigate whether the DQB1*02 allele could influence tTGAb titers and the clinicopathological expressivity of the disease.


METHODS
A total of 124 patients with celiac disease, tested for RIA tTGAb at diagnosis, were typed for HLA-DRB1, -DQA1, and -DQB1 genes and divided according to the number of DQB1*02 alleles: group 1, homozygous; group 2, heterozygous; group 3, negative.


RESULTS
The mean of tTGAb indexes was significantly higher in group 1 patients than in group 2 (P < 0.02) and group 3 patients (P < 0.01). Patients with at least 1 DQB1*02 allele showed more often a typical CD and diffuse histological lesions than did patients in the other groups.


CONCLUSIONS
The study demonstrates that tTGAb titers are HLA-DQB1*02 dose dependent, with significantly higher levels in homozygous individuals. Moreover, individuals with at least 1 HLA-DQB1*02 allele tend to have a more expressed clinical and histological form of celiac disease.
Nenna
Raffaella
R
Departments of Paediatrics, Sapienza University, Rome, Italy.
Mora
Barbara
B
Megiorni
Francesca
F
Mazzilli
Maria Cristina
MC
Magliocca
Fabio Massimo
FM
Tiberti
Claudio
C
Bonamico
Margherita
M
D000293:Adolescent; D000328:Adult; D000483:Alleles; D001323:Autoantibodies / Q000097:blood*; D002446:Celiac Disease / Q000235:genetics* / Q000276:immunology* / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D005260:Female; D005838:Genotype; D006683:HLA-DQ Antigens / Q000235:genetics*; D059866:HLA-DQ beta-Chains; D006801:Humans; D007223:Infant; D008297:Male; D011863:Radioimmunoassay; D012307:Risk Factors; D011503:Transglutaminases / Q000276:immunology*; D055815:Young Adult
D001323:Autoantibodies; D006683:HLA-DQ Antigens; D059866:HLA-DQ beta-Chains; C069051:HLA-DQB1 antigen; D011503:Transglutaminases