Association of DNA fragmentation with kinetic parameters of spermatozoa in men with idiopathic infertility

Abstract

Introduction. Despite the recent increase in the use of the analysis of sperm DNA fragmentation, the high cost and complexity of the method prevent it from being used for studying the disease pathogenesis and routine diagnostics of male infertility. A solution to this problem was the search for ejaculate parameters associated with the level of sperm DNA fragmentation. These parameters include the kinetic properties of spermatozoa obtained using computer-assisted analysis of the ejaculate (CASA). Aim of the study: To examine correlations between kinetic properties of spermatozoa determined by CASA and the degree of sperm DNA fragmentation in men with idiopathic infertility. Methods. This retrospective study involved 96 men aged 25 to 49 yrs with documented idiopathic infertility. CASA was performed using MMC Sperm software. DNA fragmentation was assessed with the terminal deoxynucleotidyl-transferase-mediated dUTP nick end labelling assay (TUNEL) using an Invitrogen Apo-DirectTM kit. Flow cytometry (Beckman Coulter Navios Flow Cytometer) was used to calculate the percentage of cells with damaged DNA. Results. The following CASA parameters had significant correlations with the degree of DNA fragmentation: 1) velocity along the straight-line path (VSL) (r=−0.522726, p<0.01); 2) velocity along the curvilinear path (VCL) (r=−0.499096, p<0.01); 3) velocity along the average path (VAP) (r=−0.429533, p<0.01); 4) the amplitude of the lateral displacement of the head (ALH) (r=−0,294779, p<0.01) 5) linearity (LIN) (r=−0.385796, p<0.01); 6) straightness (STR) (r=−0.268248, p <0.05); and 7) progressive motility (r=−0.411547, p<0.01). Conclusion. The data support the use of CASA-determined kinetic properties of spermatozoa to select patients for evaluation of DNA fragmentation. However, additional studies are needed to establish reference values for changes in the kinetic properties.