The role of interleukin-16 in eosinophilic chronic rhinosinusitis

Abstract

Eosinophilic granulocytes (Eos) are found in great numbers both in the tissue and in the mucus of patients suffering from chronic rhinosinusitis with polyposis (ECRS). Interleukin-16 (IL-16) is known as a highly potent chemotactic and chemoattractant molecule (ED 10-11) for Eos. In an open, explorative, controlled study we examined the presence of IL-16 in mucosa tissue, mucus and serum in patients suffering from ECRS and its association to Eos activation. Tissue and nasal mucus specimen from 10 previously untreated, non allergic ECRS-patients undergoing paranasal sinus surgery and from 10 healthy non sinusitis subjects, undergoing nasal surgery because of anatomic nasal obstruction were investigated by real-time (RT-) PCR targeting human IL-16 mRNA. Haematoxylin-eosin (HE) staining and immunohistochemistry of formalin embedded tissue and mucus were applied for detection and determination of the proportion of activated Eos (aEos) and IL-16. Serum IL-16 was analyzed by enzyme-linked-immunosorbent assay (ELISA). IL-16 mRNA and IL-16 protein levels were elevated in nasal mucus, polyp tissue and in the serum of ECRS patients compared to healthy controls. There was a high proportion of aEos in ECRS patients compared to healthy subjects. Serum IL-16, IL-16 mRNA expression and IL-16 protein in mucus and tissue specimens were significantly associated with the presence of aEos in polyps of ECRS patients. Immunohistochemically IL-16 protein was mainly expressed in aEos, mast cells, lymphocytes and epithelial cells. In conclusion our data indicate that IL-16 may stimulate the migration and persistence of activated Eos in ECRS. IL-16 production in ECRS patients is not mediated by Immunglobuline-E (IgE).

Markers of Antigen Presentation and Activation on Eosinophils and T Cells in the Esophageal Tissue of Patients With Eosinophilic Esophagitis

“…To identify eosinophils, we used a monoclonal EG2 antibody, which has been established to reliably identify eosinophils (12,13). Esophageal tissue was double stained with EG2 and APC cell surface proteins, CD40 receptor or CD80 ligand.…”

Serum interleukin‐16 levels in patients with nasal polyposis

“…However, serum IL‐16 levels have not been largely studied in NP patients before. Until now, there was only one study conducted in eosinophilic chronic rhinosinusitis (ECRS) patients 10. In this study, Lackner et al reported elevated IL‐16 levels in nasal mucus, polyp tissue, and in the serum of ECRS patients.…”

Red blood cell distribution width in patients with nasal polyposis

“…[13] On the other hand, a variety of other cytokines like IL-6, IL-8, IL-11, IL-16 are nonspecific markers of the inflammation in these patients. [14,15] IL-16 is a highly potent chemotactic and chemoattractant molecule for eosinophils. Lackner et al [15] reported a local increase of IL-16 in nasal polyp tissue.…”

“…[14,15] IL-16 is a highly potent chemotactic and chemoattractant molecule for eosinophils. Lackner et al [15] reported a local increase of IL-16 in nasal polyp tissue. However, Keseroglu et al [16] showed that levels of IL-16 in NP patients were also significantly increased in peripheral blood and concluded that it supports the presence of a systemic eosinophil activation in NP.…”