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Updated: Jun 24, 2026
The Examination of Peroxidase-Positive Leukocytes in Semen
Published on: January 19, 2024
Reactive oxygen species in human semen in relation to leukocyte contamination
Ivana Oborna1, Helena Fingerova, Jiri Novotny
1Department of Obstetrics and Gynecology, Faculty of Medicine and Dentistry, Palacky University, Olomouc, Czech Republic. obornai@fnol.cz
Aims:
Excessive production of reactive oxygen species (ROS) in semen has been linked to male infertility. Main sources of ROS in male genital tract are immature and/or damaged spermatozoa and a subpopulation of leukocytes known as polymorphonuclear neutrophils (PMN).
Methods:
Study group included male partners of infertile couples, 67 normospermic males (group B) and 98 males with sperm abnormalities in one or more parameters (group C), 36 fertile volunteers (group A) served as controls. Sperm parameters were determined according to WHO guidelines. The ROS production was measured by chemiluminiscence in sperm suspension in phosphate buffered saline.
Results:
All fertile volunteers in the control group had seminal PMN concentrations below 0.5x10(6)/ml. Therefore study subjects, 67 normospermic and 98 men with sperm abnormalities, were further subdivided into two subgroups of PMN concentrations: (1) < 0.5x10(6)/ml and (2) 0.5 to 1.0x10(6)/ml. The ROS production in individuals varied greatly from 1.0x10(2) to 1.7 x10(7) RLU/min per 20x10(6) spermatozoa. The ROS production in both subgroups of normospermic men and the subgroup (1) of men with sperm abnormalities was not different from the ROS production in fertile controls. The ROS production in the subgroup (2) with sperm abnormalities was significantly higher than in controls (P = 0.00004).
Conclusions:
Our findings suggest that the contribution of PMN to the ROS production in semen is negligible only up to a concentration of 0.5x10(6)/ml. This suggests that the current WHO Guidelines threshold of 1.0x10(6) PMN per ml of semen is too high and might be re-evaluated.
Insights
High concentrations of polymorphonuclear neutrophils (PMN) in semen significantly increase reactive oxygen species (ROS) production, contributing to male infertility. Current WHO guidelines for PMN levels may need re-evaluation to better address male fertility issues.
Area of Science:
- Reproductive Biology
- Andrology
- Spermatozoa Function
Background:
- Excessive reactive oxygen species (ROS) in semen is a known factor in male infertility.
- Polymorphonuclear neutrophils (PMN) and damaged spermatozoa are primary sources of seminal ROS.
Purpose of the Study:
- To investigate the relationship between polymorphonuclear neutrophil (PMN) concentration and reactive oxygen species (ROS) production in semen.
- To evaluate the adequacy of current World Health Organization (WHO) guidelines for PMN levels in infertile men.
Main Methods:
- Semen samples from fertile volunteers, normospermic males, and males with sperm abnormalities were analyzed.
- Sperm parameters were assessed according to WHO guidelines.
- Reactive oxygen species (ROS) production was measured using chemiluminescence.
Main Results:
- Fertile controls and normospermic men had PMN concentrations below 0.5x10^6/ml.
- Semen samples with PMN concentrations between 0.5 and 1.0x10^6/ml showed significantly higher ROS production compared to controls.
- ROS production was not significantly different in normospermic men and men with sperm abnormalities when PMN counts were below 0.5x10^6/ml.
Conclusions:
- The contribution of PMN to seminal ROS production is negligible at concentrations up to 0.5x10^6/ml.
- The current WHO guideline threshold of 1.0x10^6 PMN/ml may be too high and warrants re-evaluation.
- Lowering the PMN threshold could improve the identification of ROS-related male infertility factors.
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