Distribution of 3-nitrotyrosine in the nasal polyps of atopic patients.
OBJECTIVE
To investigate whether formation of nitrotyrosine in the nasal polyps of atopic patients occurs.


METHODS
A nonrandomized, retrospective, controlled qualitative and quantitative study.


METHODS
Nasal polyp tissue samples were acquired from 12 atopic patients. Control fragments of nasal mucosa were taken from 10 patients undergoing corrective surgery of the nasal septum. For routine histologic examinations, hematoxylin-eosin staining was used. Low-magnification microscopy was designed to yield pathologic characteristics and high magnification to quantify the number of eosinophils in the subepithelial connective tissue. Presence of nitrotyrosine was assessed by immunohistochemical method.


RESULTS
Hematoxylin-eosin staining revealed presence of numerous eosinophils in the epithelium and in the subepithelial connective tissue. All polyps were characterized by epithelial damage. Nitrotyrosine was present in the eosinophils, in the ciliated cell, and in cells of the damaged epithelium. Goblet cells, glands, and vessels were found to be negative. No significant differences concerning the localization of nitrotyrosine were recognized among the examined nasal polyps.


CONCLUSIONS
Nitrotyrosine immunohistochemical staining in nasal-polyp tissues suggested the existence of progressive epithelium injury caused by peroxynitrite. Consequences of peroxynitrite formation in eosinophils remain to be precisely established. The lack of nitrotyrosine in glands and blood vessels indicated that peroxynitrite does not have a significant role in the vascular and glandular dysfunction of nasal polyps.
Ruffoli
R
R
Dipartimento di Morfologia Umana e Biologia Applicata, Unità di Allergologia ed Immunologia Clinica, Facoltà di Medicina e Chirurgia, Università di Pisa, Italy. rruffoli@med.unipi.it
Ursino
F
F
Fattori
B
B
Scavuzzo
M C
MC
Paparelli
A
A
Gesi
M
M
Rocchi
V
V
Giambelluca
M A
MA
Giannessi
F
F
D000328:Adult; D016022:Case-Control Studies; D004804:Eosinophils / Q000737:chemistry; D005260:Female; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000378:metabolism*; D007150:Immunohistochemistry; D008297:Male; D009297:Nasal Mucosa / Q000737:chemistry / Q000473:pathology; D009298:Nasal Polyps / Q000737:chemistry* / Q000473:pathology; D030421:Peroxynitrous Acid / Q000378:metabolism; D012189:Retrospective Studies; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000378:metabolism*
D030421:Peroxynitrous Acid; C002744:3-nitrotyrosine; D014443:Tyrosine