Distribuição do neuroepitélio olfatório em concha média e superior em cadáveres humanos / Distribution of olfactory neuroepithelium in the middle and superior turbinate of human cadavers

AUTOR(ES)
DATA DE PUBLICAÇÃO

2008

RESUMO

INTRODUCTION: Olfactory neuroepithelium (ON) biopsy provides perspectives for several therapeutic applications, both in disorders of olfaction and in neurodegenerative diseases. Successful in vivo collection of ON is still not routine, due to a dearth of studies on ON distribution in the superior and middle turbinate (ST and MT respectively). This study describes the distribution of ON in cadaver ST and MT as determined by complete endoscopic removal of turbinates and histological analysis with hematoxylin and eosin (H&E) and immunohistochemical staining. We also analyzed the influence of gender, age, and naris side on the extent to which ON is present in the superior and middle turbinate. CASE SELECTION AND METHODS: We conducted a prospective anatomical study from March 2006 to January 2008. The superior and middle turbinates of 25 fresh cadavers (less than 12 hours post-mortem) were removed endoscopically. Each turbinate was halved into anterior and posterior fragments. Eight anatomically distinct fragments were therefore obtained from each of the 25 cadavers for a total of 200 specimens, which were analyzed through H&E staining and immunohistochemistry. Hematoxylin and eosin-stained slides were subjected to blind examination by three independent pathologists; ON distribution was graded on a fivepoint numeric scale (grade 0, 1, 2, 3, or 4). Immunohistochemistry was only positive through S-100 staining. Pairwise agreement between pathologists was assessed by means of the Kappa coefficient. The distribution of ON was analyzed regarding age, gender, time elapsed between death and specimen harvesting, symmetry between nares, and accuracy of immunohistochemistry results. RESULTS: In H&E-stained slides, olfactory neuroepithelium was present in 82.9% of ST and 17.1% of MT specimens; prevalence in the superior turbinate was therefore 4.9-fold greater (p <0.001). Immunohistochemical analysis was able to identify ON in 15 fragments, 10 of which (20%) were from the posterior half of the superior turbinate; the remaining five specimens (7.6%) were from the anterior ST. According to prevalence ratio, the odds of finding ON are 4.9 times greater in superior turbinate than in the middle turbinate (CI, 95%; 3.37.4). Of the 15 immunohistochemistry-positive fragments, seven were assigned distribution grade 3 (>50% and 75% presence of ON) on H&E staining seven others were graded 4 (>75% presence of ON). A single immunohistochemistrypositive fragment was found to have grade 2 ON distribution (i.e., it contained 26% to 50% olfactory neuroepithelium) on H&E staining. S-100 staining showed a sensitivity of 13.5% and specificity of 100% for ON detection. There was no statistically significant difference in ON prevalence when fragments were compared according to gender, age at time of death, and naris side. However, when we analyzed ON presence according to the degree of ON distribution in each side, we found no concordance. CONCLUSIONS: Total ON was distributed symmetrically between nares, but we found no concordance between sides in the manner in which ON is distributed. ON is most likely to be found in the posterior half of the superior turbinate. Hematoxylin and eosin (H&E) staining is an effective method for distinguishing ON from respiratory epithelium, as shown by high inter-rater agreement among three independent pathologists

ASSUNTO(S)

endoscopia/métodos imunoistoquímica eosin y hematoxilina amarelo de eosina (ys) immunohistochemistry cadaver study hematoxylin cadáver endoscopy/ methods mucosa olfatória/anatomia &histologia olfactory mucosa/anatomy and histology

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