Elevated serum IgE concentrations in systemic lupus erythematosus are related to history of childhood allergy, asthma, and hives.
RATIONALE: Elevated serum IgE concentrations have sometimes been found in systemic lupus erythematosus (SLE) patients. Reasons for these findings and associations with clinical and autoantibody phenotype remain controversial. METHODS: Sera were obtained from 121 recently diagnosed SLE patients (American College of Rheumatology classification) and 114 population controls. ANAs (SS/A, SS/B, Sm, RNP, Jo-1, Scl-70, dsDNA, Centromere B, and Histone) were measured using a multiplexed ANA screen (AtheNA, Inverness). Total serum IgE was measured using an Immulite 2000 (Siemens). ANA results above 120 IU/ml and total IgE results above 100 IU/ml were considered positive. RESULTS: Mean total IgEwas non-significantly elevated in patients (mean 5 245 IU/ml, 95%Confidence Limits (CL) 94-396) compared with controls (89 IU/ml, 95% CL 61-117), and 30% of SLE patients were considered IgE positive compared with 22% of controls. Being IgE positive was not clearly related to prevalence of ANAs or specific SLE clinical features in medical records, or with report of currently active disease or measured C-reactive protein levels. Positive IgE was, however, significantly more common in patients with self-reported history of childhood onset asthma, hay fever or eczema (p 5 0.029), or ever having hives (p 5 0.043), with these independent associations persisting in race-adjusted multivariate models. CONCLUSIONS: These findings suggest elevated total IgE levels in cases may be related to history of allergic disease, but are not specifically related to SLE-specific ANAs, clinical features, or activity. Further studies should investigate whether shared risk factors could account for elevated IgE levels in SLE patients with history of allergic disease.