Topical glucocorticoids downregulate COX-1 positive cells in nasal polyps.
BACKGROUND
Influx of inflammatory cells is one of the hallmarks of nasal polyposis. As glucocorticoids (GC) are known to exhibit strong anti-inflammatory effects, these drugs are frequently used in the treatment of the disease. Part of the anti-inflammatory effects of GC is attributed to their interference with prostanoid synthesis. As cyclooxygenases (COX) are key enzymes in the synthesis of both pro- (COX-1, COX-2) and anti-inflammatory prostanoids (COX-2), we investigated the role of topical GC on COX-1, COX-2 and inflammatory markers in nasal polyps (NP).


METHODS
Immunohistochemical analysis of inflammatory markers (CD68, CD117, MBP, elastase, IgE, BB-1, IL-4, IL-5 and IL-6), COX-1 and COX-2 was performed on normal nasal mucosa (NM) (n = 18), non-GC treated NP (n = 27) and topical GC treated NP (n = 12). NP groups were matched for allergy, asthma and ASA intolerance.


RESULTS
Increased numbers of eosinophils, IL-5+ cells and IgE+ cells and decreased numbers of mastcells are striking features of NP inflammation (P < 0.05). In addition, increased numbers of COX-1+ cells are observed in NP epithelium compared to NM (P < 0.05).


CONCLUSIONS
Topical GC significantly reduce the number of COX-1+ NP cells (P < 0.05), but have no significant effect on COX-2+ NP cells. No significant reduction in the number of eosinophils is observed for GC treated NP. The number of IL-5+ cells is however increased significantly upon GC treatment (P < 0.05).
Ebbens
F A
FA
Department of Otorhinolaryngology Head & Neck Surgery, Academic Medical Center, Amsterdam, The Netherlands.
Maldonado
M
M
de Groot
E J J
EJ
Alobid
I
I
van Drunen
C M
CM
Picado
C
C
Fokkens
W J
WJ
Mullol
J
J
D000287:Administration, Topical; D000328:Adult; D015415:Biomarkers / Q000032:analysis; D051545:Cyclooxygenase 1 / Q000032:analysis; D051546:Cyclooxygenase 2 / Q000032:analysis; D015536:Down-Regulation / Q000187:drug effects*; D004804:Eosinophils; D005260:Female; D005938:Glucocorticoids / Q000008:administration & dosage / Q000494:pharmacology*; D006801:Humans; D007150:Immunohistochemistry; D007249:Inflammation; D015848:Interleukin-5 / Q000032:analysis; D008297:Male; D009298:Nasal Polyps / Q000188:drug therapy / Q000473:pathology*; D055815:Young Adult
D015415:Biomarkers; D005938:Glucocorticoids; D015848:Interleukin-5; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2