Role of Circulating Immune Complex in Aspirin-sensitive Asthma

BACKGROUND & OBJECTIVES The pathogenic mechanism of aspirin-sensitive asthma (ASA-BA) remains to be further defined. To evaluate the role of circulating immune complex (CIC) in ASA-BA. SUBJECTS & METHODS We measured IgG- and IgA-IC level by ELISA using anti-C3 antibody in 33 ASA-BA patients whose sensitivity was confirmed by lysine-aspirin bronchoprovocation test, and compared with those of 14 allergic, 14 intrinsic asthma patients and 7 healthy controls. RESULTS There was no significant difference in IgG-IC level among the four groups (p > 0.05), while IgA-IC levels of aspirin-sensitive asthma were higher than those of other groups (p = 0.0035). Patients with nasal polyp had significantly higher IgG-IC than those without it (p = 0.02). No differences were found according to medication and symptom scores, and presence of atopy, rhino-sinusitis, urticaria or concurrent sensitivity to sulfite (p > 0.05). Insignificant correlation was found between IgG-IC level and asthma duration, total IgE level, or circulating eosinophil count. CONCLUSION These findings suggest a possible contribution of IgG-IC to the development of nasal polyp in ASA-BA. Further study will be needed to clarify the role of IgA-IC in the pathogenesis of ASA-BA.