title: Hypo-osmotic swelling test identifies individual spermatozoa with minimal DNA fragmentation.
abstract: One concern during intracytoplasmic sperm injection (ICSI) is that selected spermatozoa may have increased levels of DNA damage; however, the available testing for this is largely destructive in nature and therefore unsuitable as a tool for sperm selection. One alternative selection process that has previously achieved pregnancies is the hypo-osmotic swelling test (HOST). This study reports that low HOST values of neat semen samples were significantly (P<0.001) associated with increased DNA damage identified by the DNA fragmentation index (DFI) from the sperm chromatin structure assay as well as the TdT-mediated dUTP nick-end labelling (TUNEL) assay. The HOST value was highly predictive of an abnormal DFI value by receiver operating characteristic curve analysis (P<0.001). Furthermore, when individual spermatozoa were assessed for both HOST status and DNA fragmentation by TUNEL, the key HOST-induced tail-swelling grades D, E and F were most commonly associated with high HOST values and were significantly (P<0.001) associated with minimal DNA damage regardless of the DNA status of the ejaculate. The application of HOST may be a valuable tool in the routine identification and selection of viable, DNA-intact individual spermatozoa for ICSI after further research to demonstrate its efficacy and safety.
authors.affiliation: PIVET Medical Centre, 166-168 Cambridge St., Leederville, Perth, 6007 WA, Australia. jstanger@pivet.com.au
authors.forename: James D
authors.initials: JD
authors.lastname: Stanger
authors.forename: Long
authors.initials: L
authors.lastname: Vo
authors.forename: John L
authors.initials: JL
authors.lastname: Yovich
authors.forename: Ghanim
authors.initials: G
authors.lastname: Almahbobi
mesh_terms: D000328:Adult; D002843:Chromatin / Q000378:metabolism / Q000648:ultrastructure; D053938:DNA Fragmentation; D006801:Humans; D020287:In Situ Nick-End Labeling; D008297:Male; D008875:Middle Aged; D009995:Osmosis; D020554:Sperm Injections, Intracytoplasmic; D013094:Spermatozoa / Q000378:metabolism* / Q000648:ultrastructure
chemical_list: D002843:Chromatin