Impaired release of AMPs into nasal fluid of HIES- and CVID patients – A proposed model.
HIES patients (blue lines) exhibit an impaired production of IL-17A and their nasal fluid contain very low levels of LL-37 and HNP1–3 despite normal chemotactic activity and IL-8 levels. This may be explained by defects in expression of the IL-8 receptor CXCR1, resulting in non-responding neutrophils. CVID patients (red lines) also exhibited a dysregulated release of AMPs, which may be explained by the low chemotactic activity of nasal fluid as well as an impaired Th17 response. However, CVID patients have, in contrast to HIES patients, normally responding neutrophils, but this may not be sufficient, since the chemotactic signal is too weak.