title: DNA double-strand breaks and their repair in blood lymphocytes of patients undergoing angiographic procedures.
abstract: OBJECTIVE
  To adapt gamma-H2AX immunofluorescence microscopy to assessment of induction and repair of DNA double-strand breaks (DSBs) in peripheral blood lymphocytes in patients undergoing angiographic procedures.
  
  
  METHODS
  The study was approved by the institutional ethics committee. After written informed patient consents were obtained, venous blood samples were taken from 19 patients (age 23-88 years) undergoing different angiographic procedures before, during, and after (10 minutes-24 hours) the examination. Individual DSB yields were visualized by detecting the phosphorylated variant of the histone H2AX (gamma-H2AX) in lymphocytes using fluorescence microscopy. Values were correlated with dose area product. Single in vitro irradiation with 50 mGy was performed in 14 and additional fractionated irradiation with 10 x 5 mGy over a time period corresponding to the angiography duration in 4 patients. The radiation doses to the blood delivered during angiography were estimated by comparing the number of DSBs after angiography with DSB yields obtained after in vitro irradiation.
  
  
  RESULTS
  In all patients in vivo and in vitro irradiation increased the number of DSBs (0.03-1.50 per cell), even if very small doses were applied (minimum 338 microGy x m). Thereafter in both in vitro and in vivo a rapid loss of gamma-H2AX foci was observed. The number of DSBs showed a linear correlation to dose area product for specific examination regions (eg, R = 0.85, pelvic and leg arteries). Calculated radiation doses to blood delivered during angiography ranged from 2.2 to 99.9 mGy and increased if fractioned in vitro samples were used as calibration instead of single in vitro irradiations at the same total dose.
  
  
  CONCLUSIONS
  gamma-H2AX immunofluorescence microscopy is a reliable and sensitive method for measuring the induction and repair of DNA damage caused by ionizing radiation during angiography. To estimate radiation doses delivered during procedures and to consider patients individual repair capacity, postangiography DSB-yields should be compared with DSB-yields after fractioned in vitro irradiation imitating examination conditions.
authors.affiliation: Department of Radiology, University of Erlangen-Nürnberg, Erlangen, Germany. michael.kuefner@uk-erlangen.de
authors.forename: Michael A
authors.initials: MA
authors.lastname: Kuefner
authors.forename: Saskia
authors.initials: S
authors.lastname: Grudzenski
authors.forename: Siegfried A
authors.initials: SA
authors.lastname: Schwab
authors.forename: Melanie
authors.initials: M
authors.lastname: Wiederseiner
authors.forename: Martina
authors.initials: M
authors.lastname: Heckmann
authors.forename: Werner
authors.initials: W
authors.lastname: Bautz
authors.forename: Markus
authors.initials: M
authors.lastname: Lobrich
authors.forename: Michael
authors.initials: M
authors.lastname: Uder
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000792:Angiography; D002478:Cells, Cultured; D004247:DNA / Q000528:radiation effects*; D004249:DNA Damage; D004260:DNA Repair / Q000187:drug effects*; D004307:Dose-Response Relationship, Radiation; D005260:Female; D006801:Humans; D008214:Lymphocytes / Q000166:cytology / Q000502:physiology* / Q000528:radiation effects*; D008297:Male; D008875:Middle Aged; D011829:Radiation Dosage; D055815:Young Adult
chemical_list: D004247:DNA