title: Association of sister chromatid exchange frequencies in patients with ankylosing spondylitis with and without HLA-B27.
abstract: BACKGROUND
  The analysis of sister chromatid exchange (SCE) is a cytogenetic technique used to show DNA damage due to an exchange of DNA fragments between sister chromatids.
  
  
  OBJECTIVE
  To determine whether HLA-B27 positive patients with ankylosing spondylitis (AS) were associated with higher SCE frequencies than patients without B27.
  
  
  METHODS
  Lymphocytes from 38 patients with AS (15 women, 23 men) and 34 control subjects were examined. Peripheral lymphocytes were cultured in darkness for 72 hours in BrdU added culture. Metaphase chromosomes were stained with a fluorescence and a Giemsa stain after a standard harvest procedure.
  
  
  RESULTS
  The frequency of SCE was significantly increased in patients with AS compared with controls (p<0.001). Furthermore, the SCE frequencies in patients with positive HLA-B27 was much higher than in patients with negative HLA-B27 (p<0.001). The difference between SCE frequencies in the control groups with and without HLA-B27 was not significant.
  
  
  CONCLUSIONS
  There is a strong association between HLA-B27 and the frequencies of SCE in patients with AS.
authors.affiliation: Ataturk University, Medical Faculty, Department of Medical Genetics, 25240-Erzurum, Turkey. mevlitikbal@hotmail.com
authors.forename: M
authors.initials: M
authors.lastname: Ikbal
authors.forename: N
authors.initials: N
authors.lastname: Ezirmik
authors.forename: T
authors.initials: T
authors.lastname: Tos
authors.forename: I
authors.initials: I
authors.lastname: Pirim
mesh_terms: D000328:Adult; D000368:Aged; D002478:Cells, Cultured; D005260:Female; D020022:Genetic Predisposition to Disease; D015796:HLA-B27 Antigen / Q000097:blood*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012854:Sister Chromatid Exchange; D013167:Spondylitis, Ankylosing / Q000235:genetics*
chemical_list: D015796:HLA-B27 Antigen