Celiac disease in North Italian patients with autoimmune Addison's disease.
OBJECTIVE
Patients with autoimmune Addison's disease (AAD) are prone to develop other autoimmune manifestations. An increased prevalence of celiac disease (CD) has recently been demonstrated in Northern European patients with AAD. IgA deficiency is the most frequent type of immunodeficiency among humans and is present in about one in every 600 individuals in the population. IgA deficiency is frequent in patients with other autoimmune diseases, but data concerning AAD are still unavailable.


METHODS
The aim was to define the prevalence of CD and of IgA deficiency in a group of Italian patients with AAD.


METHODS
One hundred and nine patients with AAD were enrolled and examined for tissue transglutaminase autoantibodies of the IgA class, circulating levels of IgA and adrenal cortex antibodies.


RESULTS
Two (1.8%) of the patients were affected by already diagnosed CD and were already on a gluten-free diet. Out of the remaining 107 patients, four (3.7%) were found to be positive for IgA antibodies to human tissue transglutaminase. Three of the four patients who were positive for tissue transglutaminase autoantibodies agreed to undergo endoscopy and duodenal biopsies and, in one, a latent form of CD was identified. The clinical, silent or latent form of CD was present in six out of 109 (5.4%). This prevalence was significantly higher (P = 0.0001) than that reported for the Northern Italian population which was equal to 0.063%. Specifically, CD was present in 12.5% of the autoimmune polyglandular syndrome (APS) type 1 cases, in four out of 60 (6.7%) of the APS type 2 cases and in one out of 40 (2.5%) of the isolated AAD cases. IgA deficiency was present in two out of 109 patients (1.8%), all of whom had normal IgG anti-gliadin. Autoantibodies to the adrenal cortex were detected in 81 out of 109 patients (74.3%).


CONCLUSIONS
In patients with AAD there is a high prevalence of both CD and IgA deficiency. Consequently, it is important to screen for CD with tissue transglutaminase autoantibodies of the IgA class and for IgA levels.
Betterle
Corrado
C
Division of Endocrinology, Department of Medical and Surgical Sciences, University of Padua Medical School, Via Ospedale Civile 105, 35100 Padua, Italy. corrado.betterle@unipd.it
Lazzarotto
Francesca
F
Spadaccino
Aglaura Cinzia
AC
Basso
Daniela
D
Plebani
Mario
M
Pedini
Beniamino
B
Chiarelli
Silvia
S
Albergoni
Mariapaola
M
D000224:Addison Disease / Q000150:complications* / Q000276:immunology; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001323:Autoantibodies / Q000097:blood; D002446:Celiac Disease / Q000453:epidemiology / Q000209:etiology* / Q000276:immunology; D002648:Child; D015331:Cohort Studies; D004247:DNA / Q000737:chemistry / Q000235:genetics; D016145:Endoscopy, Digestive System; D005260:Female; D020022:Genetic Predisposition to Disease; D006681:HLA-D Antigens / Q000737:chemistry / Q000235:genetics; D006239:Haplotypes; D006801:Humans; D017098:IgA Deficiency / Q000097:blood*; D007558:Italy / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D015995:Prevalence
D001323:Autoantibodies; D006681:HLA-D Antigens; D004247:DNA