title: Diagnostic accuracy of sperm chromatin dispersion test to evaluate sperm deoxyribonucleic acid damage in men with unexplained infertility.
abstract: OBJECTIVE
  To compare the sperm chromatin dispersion (SCD) test and the terminal uridine nick-end labeling (TUNEL) assay for assessment of sperm DNA damage.
  
  
  METHODS
  Prospective comparative experimental study.
  
  
  METHODS
  Andrology laboratory.
  
  
  METHODS
  Twenty subfertile men with unexplained infertility.
  
  
  METHODS
  Sperm DNA damage was determined in the same semen samples using the TUNEL assay with fluorescence microscopy and the SCD test with bright-field microscopy.
  
  
  METHODS
  Correlation coefficient and receiver operating characteristic analysis outcomes. The TUNEL assay was used as the reference standard to identify optimal cutoff points for assessing DNA damage by SCD.
  
  
  RESULTS
  The SCD test detected a significantly higher proportion of sperm with damaged DNA (20.6% ± 14.0%) than the TUNEL assay (11.5% ± 7.3%). Spearman's rank correlation showed that the methods were not comparable (r = 0.29). Receiver operating characteristic analysis revealed that 15% was the best SCD cutoff point to classify patients within the same levels of DNA fragmentation, normal or abnormal, as determined by the TUNEL assay, with an accuracy of 69%.
  
  
  CONCLUSIONS
  The SCD test is more sensitive than the TUNEL assay for the assessment of DNA damage in men with unexplained infertility. Although the methods are poorly correlated, SCD may discriminate men with normal and abnormal sperm DNA damage with moderate accuracy when compared with TUNEL. It is important to distinguish between the methods because they differently evaluate sperm DNA damage.
authors.affiliation: ANDROFERT, Andrology and Human Reproduction Clinic, Referral Center for Male Reproduction, Campinas, São Paulo, Brazil.
authors.forename: Cinthia M
authors.initials: CM
authors.lastname: Feijó
authors.affiliation: ANDROFERT, Andrology and Human Reproduction Clinic, Referral Center for Male Reproduction, Campinas, São Paulo, Brazil. Electronic address: s.esteves@androfert.com.br.
authors.forename: Sandro C
authors.initials: SC
authors.lastname: Esteves
mesh_terms: D000293:Adolescent; D000328:Adult; D002843:Chromatin / Q000473:pathology / Q000502:physiology*; D004249:DNA Damage / Q000502:physiology*; D006801:Humans; D007248:Infertility, Male / Q000175:diagnosis* / Q000503:physiopathology; D008297:Male; D055101:Semen Analysis / Q000379:methods / Q000592:standards*; D013094:Spermatozoa / Q000473:pathology / Q000502:physiology*; D055815:Young Adult
chemical_list: D002843:Chromatin
keywords: ROC curve; Sperm DNA damage; diagnosis; in situ nick-end labeling; sperm chromatin dispersion test