Association between IgE levels and asthma severity among African American, Mexican, and Puerto Rican patients with asthma

BackgroundHigh levels of IgE are associated with asthma. Whether higher levels of IgE are associated with more severe asthma is still unclear.ObjectiveTo determine whether IgE is associated with asthma severity among Latino and African American subjects with asthma.MethodsWe assessed lung function and asthma severity among African American, Mexican, and Puerto Rican patients with asthma with high IgE levels (≥100 IU/mL; n = 492) and compared these values to those of patients with asthma with low IgE levels (<100 IU/mL; n = 247). We also examined IgE as a continuous variable among these groups.ResultsPatients with asthma with high IgE had a lower mean FEV1 (87.6 ± 17.1, percent of predicted) than patients with asthma with low IgE (91.5 ± 17.0; P = .031). Regardless of race and ethnicity, baseline FEV1, forced expiratory flow, and FEV1/forced vital capacity were lower among subjects with high IgE than among subjects with low IgE (P = .031, P < .0001, P = .0001, respectively). In addition, 54.7% of patients with asthma with high IgE had been previously hospitalized, compared with 44.1% of patients with asthma with low IgE (odds ratio, 1.33; 95% CI, 1.04-1.71).ConclusionHigher IgE is associated with lower baseline lung function and more severe asthma among these populations.Clinical implicationsAmong patients with asthma from 3 ethnically distinct groups, total IgE levels are inversely correlated with baseline lung function and asthma severity.