OBJECTIVETo determine the sperm mtDNA content, mtDNA4977bp deletion and ROS in the seminal plasma of normal and leukocytospermia men, and to investigate the correlation of the changes of sperm mtDNA with the increase of leukocytes and reactive oxgygen species (ROS) in the seminal plasma.

METHODSSeventy-eight semen samples from leukocytospermia patients and 31 from healthy donors were divided into 3 layers, supernatant fluid, 30% sperm and 80% sperm, by Percoll gradient centrifugation, their sperm mtDNA content and mtDNA4977bp deletion quantitatively analyzed by real-time PCR, and the level of ROS determined by flow cytometry.

RESULTSThe ROS in the seminal plasma and the sperm mtDNA contents of the three layers were all significantly higher in the leukocytospermia group than in the healthy control (P < 0.01). In the supernatant fluid and 80% layers, mtDNA4977bp deletion showed no obvious difference between the control and the leukocytospermia group, but was significantly higher in the 30% layer of the latter (P < 0.01). The ROS level was found positively correlated with the mtDNA content in the 30% (r = 0.347, P < 0.01) and the 80% layer (r = 0.456, P < 0.01), but not in the supernatant layer.

CONCLUSIONThe increase of leukocytes and ROS may be one of the causes of the enhanced sperm mtDNA content, but has no significant impact on the mtDNA4977bp deletion.