title: Micronucleus evaluation in mitogen-stimulated lymphocytes of narrow-band (311 nm TL01) UVB-treated patients.
abstract: BACKGROUND
  Narrow-band UVB (311 nm) lamps (TL01) are being increasingly used for phototherapy of psoriasis and other dermatoses, for their excellent effect compared with broad-band UVB sources and photochemotherapy. It is acknowledged that the TL01 lamp is probably two to three times more carcinogenic per minimum erythema dose than broad-band UVB, but the cumulative dose is considerably less than broadband UVB sources. Micronucleus (MN) test is used to detect both clastogenic (breaking) and aneugenic (abnormal segregation) effect of physical/chemical agents on chromosomes. The aim of this study is to evaluate MN frequencies in mitogen-stimulated lymphocytes of narrow-band UVB-treated patients.
  
  
  METHODS
  Frequency of micronuclei in 72 h cultivated/mitogen-stimulated lymphocytes of 36 patients (age 7-73 years, mean+/-SD: 25.33+/-18.54) have been evaluated at pretreatment and after 20, 40, 60 sessions of narrowband UVB treatment.
  
  
  RESULTS
  While the beginning MN frequency +/-SD (%) was 1.07+/-0.63, it increased to 1.47+/-0.92, 1.47+/- 0.77, 1.41+/-0.31 corresponding, respectively, to 20, 40, 60 sessions. These sessions reciprocally correspond to 0.85+/-0.23, 2.97+/-0.72, 5.68+/-1.46 J/cm(2) doses of narrow-band UVB. Difference of MN frequency was statistically significant (P=0.002). Significant differences have been observed between the initial MN frequency and after that of 20, 40, 60 sessions (P=0.001, 0.004, 0.002, respectively).
  
  
  CONCLUSIONS
  The results of this study show that narrow-band UVB treatment causes a detectable chromosome damaging effect.
authors.affiliation: Department of Dermatology, Medical Faculty, Erciyes University, TR-3809, Kayseri, Turkey. ferabas@erciyes.edu.tr
authors.forename: Ayten
authors.initials: A
authors.lastname: Ferahbas
authors.forename: Hamiyet
authors.initials: H
authors.lastname: Donmez-Altuntas
authors.forename: Zuhal
authors.initials: Z
authors.lastname: Hamurcu
authors.forename: Ekrem
authors.initials: E
authors.lastname: Aktas
authors.forename: Serap
authors.initials: S
authors.lastname: Utas
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D004307:Dose-Response Relationship, Radiation; D005260:Female; D006801:Humans; D016014:Linear Models; D008214:Lymphocytes / Q000528:radiation effects*; D008297:Male; D015162:Micronucleus Tests; D008875:Middle Aged; D012871:Skin Diseases / Q000532:radiotherapy; D018709:Statistics, Nonparametric; D014467:Ultraviolet Therapy / Q000009:adverse effects*