Immunologic Response to Fungus is not Universally Associated with Rhinosinusitis

Abstract

OBJECTIVE: Immunologic response to fungal antigens has been cited as an etiologic factor in chronic rhinosinusitis (CRS). Previous work demonstrated a significant cytokine response in CRS patients that did not correlate with an immunoglobulin E (IgE) response. This study was performed in an effort to replicate these findings in a more geographically diverse population. DESIGN: Prospective in vitro study. SETTING: Two academic tertiary rhinologic practices in Texas and Utah. METHODS: Serum and peripheral blood monocytes (PBMC) were obtained from 10 CRS patients and seven controls. Total IgE and fungal-specific IgE levels were determined. Cytokine levels were measured after PBMC exposure to Alternaria, Aspergillus, Cladosporium, and Penicillium extracts. Correlations between cytokine responses and presence of CRS as well as IgE and IgG were determined. RESULTS: Interleukin-5 (IL-5) was produced after Alternaria extract exposure in both CRS patients and controls, but the production was heterogenous and did not correlate with the presence of CRS. IL-5 levels after Alternaria extract exposure correlated strongly with levels of Alternaria-specific IgE in both CRS patients and controls. IL-5 production did not correlate with IgG levels. IL-4, IL-13, and interferon-gamma production did not differ between CRS patients and controls. CONCLUSIONS: In contrast to previously reported data, IL-5 responses to Alternaria extract were not predictive of CRS presence. Our results in patients from Utah and Texas significantly differ from previously published findings in predominantly Midwestern patients. The immunologic response to fungal extracts appears to be heterogenous and may differ based on geography, allergy status, and/or other as-yet unknown factors.