Helicobacter pylori infection and autoimmune thyroid disease in young patients: the disadvantage of carrying the human leukocyte antigen-DRB1*0301 allele.
OBJECTIVE
Pathogenesis of autoimmune thyroid disease (ATD) is multifactorial. Helicobacter pylori (Hp) infection has been proposed to be involved in nongastrointestinal conditions and reported more frequently in ATD adult patients. We evaluated the prevalence of Hp antibodies in young ATD patients and investigated the possibility that a susceptible immunogenetic profile could influence the development of ATD in subjects with Hp infection.


METHODS
We retrospectively studied 90 children with ATD (median age 11.2 yr), 70 age- and sex-matched healthy subjects as controls, and 65 patients with Turner syndrome (median age 18.8 yr). Antibodies to Hp were determined at diagnosis in ATD patients and, in Turner patients, at the last control in cases without ATD and before the appearance of thyroid autoantibodies in the others. Serological and molecular human leukocyte antigen (HLA) typing for classes I and II polymorphisms was performed.


RESULTS
Prevalence of positive Hp serology resulted significantly higher in ATD patients than controls (P = 0.032). No association was found between individual HLA alleles and Hp serology. HLA-A1, B8, and DRB1*0301 were found significantly associated with ATD. A significant interaction between HLA-DRB1*0301 and Hp infection was present in ATD patients and not controls (P = 0.007), suggesting that the copresence of these two factors might favor ATD development. A similar phenomenon was observed in Turner syndrome patients (P = 0.02; cumulative Mantel test, P = 0.0001).


CONCLUSIONS
Another target of Hp-elicited immune inflammatory response might be the thyroid gland in subjects with a peculiar immunogenetic profile so that ATD may be a consequence. Our findings suggest the opportunity of eradicating Hp infection in children with ATD and/or susceptible HLA alleles.
Larizza
Daniela
D
Department of Pediatric Sciences, University of Pavia and Istituto di Ricovero e Cura a Carattere Scientifico Policlinico San Matteo, 27100 Pavia, Italy. d.larizza@smatteo.pv.it
Calcaterra
Valeria
V
Martinetti
Miryam
M
Negrini
Riccardo
R
De Silvestri
Annalisa
A
Cisternino
Mariangela
M
Iannone
A M
AM
Solcia
Enrico
E
D000293:Adolescent; D000328:Adult; D000483:Alleles; D000907:Antibodies, Bacterial / Q000032:analysis; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D005260:Female; D005787:Gene Frequency; D006684:HLA-DR Antigens / Q000235:genetics*; D059811:HLA-DRB1 Chains; D016481:Helicobacter Infections / Q000150:complications* / Q000453:epidemiology / Q000235:genetics*; D016480:Helicobacter pylori; D006650:Histocompatibility Testing; D006801:Humans; D007223:Infant; D008297:Male; D011110:Polymorphism, Genetic; D012189:Retrospective Studies; D013967:Thyroiditis, Autoimmune / Q000150:complications* / Q000453:epidemiology / Q000235:genetics*; D014424:Turner Syndrome / Q000235:genetics / Q000503:physiopathology
D000907:Antibodies, Bacterial; D006684:HLA-DR Antigens; D059811:HLA-DRB1 Chains; C553502:HLA-DRB1*03:01 antigen