Prevalence of asthma and atopy in sarcoidosis

BACKGROUND AND OBJECTIVE: We hypothesized that the prevalence of allergic disorders, characterized by the release of type 2 cytokines (IL-4, IL-5, IL-10), would be lower in sarcoidosis in which there is a dominant type 1 immune response (IL-2, interferon-gamma). The objective was to measure the prevalence of atopy and self-reported asthma in patients with sarcoidosis. METHODS: Sarcoidosis patients (n = 136, 72 M, age range 22-75), recruited in the outpatient setting, completed a modified European Community Respiratory Health Survey. 123 of these patients provided blood for allergy testing. RESULTS: For the cohort as a whole the self-reported prevalence of asthma ever (21.5%) and asthma attack in the last 12 months (7.5%), was high as was wheezing (42.1%), breathlessness with wheeze (22.3%) and use of an asthma medication (13.1%). The prevalence of atopy was 34%. These data are not different from the previously reported prevalence of asthma and atopy in New Zealand. CONCLUSIONS: The same prevalence of asthma symptoms and atopy as in the normal population suggests that the immune system is not skewed away from mounting T helper type 2 immune responses in sarcoidosis.