We investigated the relationship between disease activity and total Ig
E concentration in the sera of patients with active systemic lupus ery
thematosus (SLE). In addition, the prevalence of personal and family h
istory of allergic rhinitis and asthma were examined with a questionna
ire and immediate skin tests for common inhalant allergens in 24 patie
nts in remission. In the 20 patients with active disease, we found tha
t IgE concentration was significantly higher during the periods of act
ive disease than the periods of remission. This elevation was not asso
ciated with an elevation in total serum IgG concentrations. The increa
se in IgE concentration during disease activity in patients with activ
e nephritis was significantly higher than in patients without nephriti
s. Of the 24 patients in remission, only one reported allergic rhiniti
s, and two had positive skin tests for inhalant allergens. We conclude
d that, although patients with SLE do not have an increased rate of at
opic disorders, serum IgE rises during disease activity and is associa
ted with active nephritis. This phenomenon suggests that IgE may be in
volved in the pathogenesis of SLE, particularly in patients with nephr
itis.