Biopsies of Olfactory Epithelium in Patients With Parkinson's Disease

Mov Disord. 2009 Apr 30;24(6):906-14. doi: 10.1002/mds.22464.


Parkinson's disease (PD) is a neurodegenerative disorder involving several neuronal systems. Impaired olfactory function may constitute one of the earliest symptoms of PD. However, it is still unclear to what degree changes of the olfactory epithelium may contribute to dysosmia and if these changes are different from those of other hyposmic or anosmic patients. This study aimed to investigate the hypothesis that olfactory loss in PD is a consequence of specific PD-related damage of olfactory epithelium. Biopsies of 7 patients diagnosed with PD were taken. Six patients with PD were hyposmic, one anosmic. As non-PD controls served 9 patients with hyposmia, 9 with anosmia, and 7 normosmic individuals. Further, nasal mucosa of 4 postmortem individuals was investigated. Immunohistochemical examinations were performed with antibodies against olfactory marker protein (OMP), protein gene product 9.5 (PGP 9.5), beta-tubulin, (BT), proliferation-associated antigen (Ki 67), the stem cell marker nestin, cytokeratin, p75NGFr, and alpha-synuclein. Most of the biopsy specimens exhibited irregular areas of olfactory-like, dysplastic epithelium positive for either PGP 9.5 or BT, but negative for OMP. No major histochemical differences in either the expression or distribution of these proteins were observed in the olfactory epithelium of patients with PD compared with controls. Reverse transcription PCR (RT-PCR) data indicated mRNA for OMP in almost all subjects, independently of their olfactory performance. These data support the idea that olfactory loss in Parkinson's disease is not a consequence of damage to the olfactory epithelium but rather results from distinct central-nervous abnormalities.

MeSH terms

  • Adult
  • Age Factors
  • Aged
  • Biopsy / methods
  • Female
  • Forkhead Transcription Factors / metabolism
  • Humans
  • Ki-67 Antigen / metabolism
  • Male
  • Middle Aged
  • Nerve Tissue Proteins / metabolism
  • Olfaction Disorders / etiology
  • Olfaction Disorders / metabolism
  • Olfaction Disorders / pathology
  • Olfactory Marker Protein / genetics
  • Olfactory Marker Protein / metabolism
  • Olfactory Mucosa / metabolism
  • Olfactory Mucosa / pathology*
  • Parkinson Disease / complications
  • Parkinson Disease / pathology*
  • Receptors, Nerve Growth Factor / metabolism
  • Ubiquitin Thiolesterase / metabolism
  • Young Adult


  • FOXK1 protein, human
  • Forkhead Transcription Factors
  • Ki-67 Antigen
  • NGFR protein, human
  • Nerve Tissue Proteins
  • OMP protein, human
  • Olfactory Marker Protein
  • Receptors, Nerve Growth Factor
  • UCHL1 protein, human
  • Ubiquitin Thiolesterase