Familial aggregation of IgAD and autoimmunity.
BACKGROUND
The prevalence of autoimmunity is thought to be increased among IgA deficient (IgAD) individuals. However, it is currently unclear if the two conditions coincide within families.


OBJECTIVE
To evaluate the prevalence of autoimmunity among IgAD individuals and their 1 degrees relatives.


METHODS
A total of 43 IgAD individuals (32 adults and 11 children) and all available 1 degrees relatives were evaluated by a physician. A family history of autoimmunity was obtained, together with physical examination and a structured questionnaire that focused on symptoms and signs suggestive of autoimmunity.


RESULTS
Eight of the 32 (25%) adult IgAD, were found to have definite autoimmunity, with organ specific- and systemic autoimmune diseases equally distributed. None of the IgAD children had autoimmunity. Among the 1 degrees relatives, 27/269 (10%) had autoimmunity, compared to an estimate of 5% in the general population (p<0.05).


CONCLUSIONS
Autoimmune diseases are highly prevalent in individuals with IgAD and more common in their 1 degrees relatives than expected, thus, suggesting a possible common genetic component.
Jorgensen
Gudmundur H
GH
Department of Medicine, University of Iceland, Reykjavík, Iceland.
Thorsteinsdottir
Ingunn
I
Gudmundsson
Sveinn
S
Hammarstrom
Lennart
L
Ludviksson
Bjorn R
BR
D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D000368:Aged; D015551:Autoimmunity / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D017098:IgA Deficiency / Q000235:genetics*; D007070:Immunoglobulin A / Q000235:genetics* / Q000276:immunology; D008297:Male; D008875:Middle Aged; D010375:Pedigree; D011795:Surveys and Questionnaires
D007070:Immunoglobulin A