title: Neuron-specific enolase in nasal secretions as a novel biomarker of olfactory dysfunction in chronic rhinosinusitis.
abstract: BACKGROUND
  Olfactory dysfunction is a diagnostic criterion for chronic rhinosinusitis (CRS). During chronic inflammation and olfactory neuronal damage in CRS, it is likely that neuron-specific enolase (NSE) can leak into nasal secretions (NS) and serum. Therefore, we postulated that NSE levels in NS and in circulation may be indicative of olfactory dysfunction in CRS.
  
  
  OBJECTIVE
  To evaluate the relationship between the NS and serum concentrations of NSE with olfactory dysfunction in subjects with CRS.
  
  
  METHODS
  The patients with CRS were classified into two groups, depending on the presence of polyps: CRS without nasal polyps (CRSsNP) and CRS with nasal polyps (CRSwNP). A group of age- and sex-matched healthy volunteers served as controls. Olfactory function assessment was performed by using Sniffin' Sticks. NSE concentrations in serum and NS were analyzed by using the enzyme immunometric assay kit specific for the γ subunit.
  
  
  RESULTS
  The study included 46 patients with CRSsNP, 25 women (54.3%) and 21 men (45.7%), mean (standard deviation [SD]) age, 34.1 ± 12.3 years; and 54 patients with CRSwNP, 24 women (44.4%) and 30 men (55.6%), mean (SD) age, 37.9 ± 17.5 years. A group of 40 healthy volunteers who were matched for age and sex served as controls. Significantly higher serum and NS levels of NSE were measured in patients with CRS compared with healthy controls (p < 0.001). In the CRSwNP group, both mean (SD) serum (83.5 ± 37.6 ng/mL) and mean (SD) NS (6.1 ± 2.3 ng/mL) levels of NSE were significantly higher than in the CRSsNP group (46.4 ± 7.3 ng/mL [p < 0.001] and 1.7 ± 0.5 ng/mL [p < 0.001], respectively). In both the CRSsNP and CRSwNP groups (but not in the healthy controls), significant negative correlations between NS NSE levels and TDI scores (r = -0.63, p < 0.001 for the CRSwNP group, and r = -0.51, p < 0.001 for CRSsNP group) were observed, which meant that higher NSE was associated with worse olfactory function.
  
  
  CONCLUSIONS
  The study demonstrated a contribution of CRS to NSE and olfactory dysfunction.
authors: Pathophysiology Department, 2Normal Physiology Department, Chita Medical Academy, Chita, Russia.
authors: Namjil N
authors: NN
authors: Tsybikov
authors: Elena V
authors: EV
authors: Egorova
authors: Boris I
authors: BI
authors: Kuznik
authors: Elena V
authors: EV
authors: Fefelova
authors: Eli
authors: E
authors: Magen
mesh_terms: D000328:Adult; D000377:Agnosia / Q000150:complications / Q000175:diagnosis*; D015415:Biomarkers / Q000097:blood*; D002908:Chronic Disease; D005260:Female; D006801:Humans; D008297:Male; D009298:Nasal Polyps / Q000150:complications / Q000175:diagnosis*; D010751:Phosphopyruvate Hydratase / Q000097:blood*; D012220:Rhinitis / Q000150:complications / Q000175:diagnosis*; D012852:Sinusitis / Q000150:complications / Q000175:diagnosis*; D055815:Young Adult
chemical_list: D015415:Biomarkers; D010751:Phosphopyruvate Hydratase