title: Effects of intranasal phototherapy on nasal mucosa in patients with allergic rhinitis.
abstract: BACKGROUND
  Rhinophototherapy has been shown to be effective in the treatment of allergic rhinitis. Considering that phototherapy with ultraviolet light (UV) induces DNA damage, it is of outstanding importance to evaluate the damage and repair process in human nasal mucosa.
  
  
  METHODS
  We have investigated eight patients undergoing intranasal phototherapy using a modified Comet assay technique and by staining nasal cytology samples for cyclobutane pyrimidine dimers (CPDs), which are UV specific photoproducts.
  
  
  RESULTS
  Immediately after last treatment Comet assay of nasal cytology samples showed a significant increase in DNA damage compared to baseline. Ten days after the last irradiation a significant decrease in DNA damage was observed compared to data obtained immediately after finishing the treatment protocol. Difference between baseline and 10 days after last treatment was not statistically significant. Two months after ending therapy, DNA damage detected by Comet assay in patients treated with intranasal phototherapy was similar with that of healthy individuals. None of the samples collected before starting intranasal phototherapy stained positive for CPDs. In all samples collected immediately after last treatment strong positive staining for CPDs was detected. The number of positive cells significantly decreased 10 days after last treatment, but residual positive staining was present in all the examined samples. This finding is consistent with data reported in skin samples after UV irradiation. Cytology samples examined two months after ending therapy contained no CPD positive cells.
  
  
  CONCLUSIONS
  Our results suggest that UV damage induced by intranasal phototherapy is efficiently repaired in nasal mucosa.
authors.affiliation: Department of Dermatology and Allergology, University of Szeged, P.O. Box 427, H-6701 Szeged, Hungary.
authors.forename: A
authors.initials: A
authors.lastname: Koreck
authors.forename: A
authors.initials: A
authors.lastname: Szechenyi
authors.forename: M
authors.initials: M
authors.lastname: Morocz
authors.forename: A
authors.initials: A
authors.lastname: Cimpean
authors.forename: Zs
authors.initials: Z
authors.lastname: Bella
authors.forename: E
authors.initials: E
authors.lastname: Garaczi
authors.forename: M
authors.initials: M
authors.lastname: Raica
authors.forename: T R
authors.initials: TR
authors.lastname: Olariu
authors.forename: I
authors.initials: I
authors.lastname: Rasko
authors.forename: L
authors.initials: L
authors.lastname: Kemeny
mesh_terms: D002478:Cells, Cultured; D020552:Comet Assay; D004249:DNA Damage; D004260:DNA Repair; D004847:Epithelial Cells / Q000528:radiation effects; D006801:Humans; D009297:Nasal Mucosa / Q000737:chemistry / Q000473:pathology / Q000528:radiation effects*; D010789:Phototherapy / Q000009:adverse effects*; D011740:Pyrimidine Dimers / Q000032:analysis; D006255:Rhinitis, Allergic, Seasonal / Q000532:radiotherapy*; D014466:Ultraviolet Rays / Q000009:adverse effects*
chemical_list: D011740:Pyrimidine Dimers