Autoimmune diseases in asthma.
BACKGROUND
Previous research has suggested an inverse relationship between T-helper 2-related atopic disorders, such as asthma, and T-helper 1-related autoimmune diseases. One controversial hypothesis postulates that asthma provides a protective effect for the development of autoimmune-related disorders.


OBJECTIVE
To assess the rate of newly diagnosed autoimmune disorders in a large cohort of young adults.


METHODS
Using cross-sectional data from the Israeli Defense Force database, the authors analyzed the prevalence of autoimmune disorders in asthmatic and nonasthmatic military personnel between 1980 and 2003. A follow-up study traced newly diagnosed autoimmune disorders among asthmatic and nonasthmatic individuals from the time of enrollment in military service until discharge (22 and 36 months for women and men, respectively).


METHODS
General community.


METHODS
307,367 male and 181,474 female soldiers in compulsory military service who were between 18 and 21 years of age.


METHODS
Cases of type 1 diabetes mellitus, vasculitis, immune thrombocytopenic purpura, inflammatory bowel disease, rheumatoid arthritis, and the antiphospholipid syndrome.


RESULTS
Of 488,841 participants at enrollment, significantly more women than men had autoimmune disorders. Compared with asthmatic women, nonasthmatic women had a significantly higher prevalence of all autoimmune disorders except for the antiphospholipid syndrome. Type 1 diabetes mellitus, vasculitis, and rheumatoid arthritis were less prevalent in men with asthma than in those without. During the follow-up period, vasculitis and rheumatoid arthritis were more frequently diagnosed in nonasthmatic persons of both sexes. There was a significantly higher incidence of immune thrombocytopenic purpura, inflammatory bowel disease, and the antiphospholipid syndrome in nonasthmatic women and a statistically significantly higher incidence of type 1 diabetes mellitus in nonasthmatic men.


CONCLUSIONS
The study was limited to a population of young military recruits; therefore, its findings are not necessarily applicable to the general population. Because of the noninterventional nature of the study, it describes associations but cannot prove causality.


CONCLUSIONS
Asthma status may affect the prevalence of major autoimmune disorders. Preexisting asthma seems to protect against the development of autoimmune disorders to varying degrees in men and women.
Tirosh
Amir
A
Department of Internal Medicine A+C, Sheba Medical Center, Tel Hashomer, Israel. amirt@bgumail.bgu.ac.il
Mandel
Dror
D
Mimouni
Francis B
FB
Zimlichman
Eyal
E
Shochat
Tzippora
T
Kochba
Ilan
I
D001249:Asthma / Q000150:complications* / Q000276:immunology; D001327:Autoimmune Diseases / Q000150:complications / Q000453:epidemiology* / Q000276:immunology; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D015995:Prevalence; D018417:Th1 Cells / Q000502:physiology; D018418:Th2 Cells / Q000502:physiology