Total serum IgE levels in systemic lupus erythematosus and associations with childhood onset allergies.

ABSTRACT

Elevated serum IgE has been described in systemic lupus erythematosus (SLE), but associations with disease risk and characteristics remain unresolved. We assessed total serum IgE levels and atopy (IgE > 100 IU/ml) in recently diagnosed SLE patients (n = 228) compared with population controls (n = 293) and in relation to disease activity, autoantibodies, clinical features, total immunoglobulins, C-reactive protein, and allergy history. Multivariate models estimated determinants of IgE and atopy in patients and controls, and associations of SLE with allergy and atopy. Total IgE levels were higher in patients than controls (median = 42 vs. 29 IU/ml); 32% of patients and 25% of controls were atopic (p = 0.06). IgE levels were significantly higher in non-Whites and patients reporting childhood onset (<18 years) asthma and hives, and in controls reporting childhood asthma, hay fever, eczema, and adult onset hives. After accounting for racial differences, atopy was not associated with SLE, nephritis, or other clinical and laboratory parameters. In sum, our findings provide limited evidence of a direct association between total serum IgE and SLE overall or with other disease characteristics after adjusting for demographic characteristics and allergy history. Future studies may want to explore potentially shared risk factors for development of allergy, atopy, and SLE.