Increased presence of dendritic cells and dendritic cell chemokines in the sinus mucosa of chronic rhinosinusitis with nasal polyps and allergic fungal rhinosinusitis.

BACKGROUND: The aim of this study was to determine if there is a link between local dendritic cells (DCs) and various subtypes of chronic rhinosinusitis (CRS): CRS with nasal polyposis (CRSwNP), CRS without nasal polyposis (CRSsNP), and allergic fungal rhinosinusitis (AFRS). Once DC presence was established we considered possible mechanisms for DC recruitment to the sinuses.
METHODS: Biopsy specimens were taken from the osteomeatal complex during endoscopic sinus surgery in patients with AFRS (n ≥ 5), CRSsNP (n ≥ 6), and CRSwNP (n ≥ 6). Control patients (n ≥ 5) were undergoing either tumor resection or repair of cerebrospinal fluid leak and had no radiographic or endoscopic evidence of inflammatory sinus disease. Tissue samples were immunohistochemically stained for DC marker, CD209, costimulatory molecules, CD80 and CD86, and chemokine receptors, CCR2 and CCR6. Sinus tissue lysates were examined for levels of the DC chemoattractants, chemokine ligand 2 (CCL2) and CCL20.
RESULTS: Analysis of sinus tissue from AFRS and CRSwNP revealed elevated numbers of cells staining positive for CD209, CD80, CD86, CCR2, and CCR6 compared to controls. CCL2 and CCL20 levels were elevated in AFRS and CRSwNP compared to controls, similar to increases in their receptors, CCR2 and CCR6, respectively. While there were trends toward increases in all markers in CRSsNP, none was statistically significant compared to control.
CONCLUSION: AFRS and CRSwNP have increased numbers of DCs displaying costimulatory molecules, DC chemoattractants, and their corresponding receptors in the sinus mucosa compared to controls. These differences represent a possible mechanism for increased numbers of DCs with a T helper 2 (Th2)-skewed profile seen in CRSwNP and AFRS.