Positive myeloperoxidase staining (Endtz test) as an indicator of excessive reactive oxygen species formation in semen
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M Shekarriz1, R K Sharma, A J Thomas
1Department of Urology, Cleveland Clinic Foundation, Ohio 44195, USA.
Purpose:
Although the significance of leukocytospermia in semen remains controversial, evidence exists that white blood cells (WBCs) may adversely affect sperm function and act as a potential cofactor in male infertility. Nevertheless, the mechanisms by which leukocytes may alter sperm function in vitro is unknown. Recent investigations suggest that reactive oxygen species (ROS) generated by the polymorphonuclear (PMN) granulocytes could adversely affect sperm function. The objective of this study was to investigate the relationship between the presence of leukocytospermia as determined by the Endtz test and the excessive formation of ROS.
Methods:
The WBC concentration and ROS formation in human semen, obtained from men consulting for infertility, were assessed and compared to that of normal donors. ROS was measured by a chemiluminescence assay using luminol and a Berthold luminometer. The WBC concentration was determined with a myeloperoxidase staining technique (Endtz test). Specimens were obtained from 94 subjects (20 donors, 74 patients).
Results:
Of the 20 donors, 2 were Endtz positive and ROS positive; 18 were Endtz negative with 2 (11%) ROS positive. In the patient group (n = 74), 26 (35%) were ROS positive, and 17 were Endtz positive and found to be ROS positive. Of the 57 Endtz-negative patients, 9 (15%) were ROS positive. The positive Endtz test results correlated strongly with positive ROS formation in patients and donors (P < 0.001).
Conclusions:
Our results indicate that the simple, cost-efficient Endtz test could be used as an indicator of excessive ROS formation in semen.
Insights
The Endtz test can identify excessive reactive oxygen species (ROS) in semen, which are linked to white blood cell (WBC) presence and male infertility. This simple test may help diagnose fertility issues.
Area of Science:
- Reproductive biology
- Andrology
- Spermatozoa function
Background:
- Leukocytospermia (white blood cells in semen) is controversially linked to male infertility.
- White blood cells (WBCs) may impair sperm function, potentially through reactive oxygen species (ROS).
- The exact mechanisms of how leukocytes affect sperm in vitro are not fully understood.
Purpose of the Study:
- To investigate the relationship between leukocytospermia, identified by the Endtz test, and excessive ROS formation in human semen.
- To assess if the Endtz test can serve as an indicator for elevated ROS levels.
Main Methods:
- Semen samples from 94 men (20 donors, 74 infertile patients) were analyzed.
- White blood cell concentration was determined using the myeloperoxidase staining technique (Endtz test).
- Reactive oxygen species (ROS) levels were quantified via a chemiluminescence assay.
Main Results:
- A strong correlation was observed between positive Endtz test results and elevated ROS formation in both donors and patients (P < 0.001).
- In the patient group, 35% showed elevated ROS, with 17 of 57 Endtz-positive patients also being ROS positive.
- Even in Endtz-negative patients, 15% exhibited ROS positivity.
Conclusions:
- The Endtz test is a reliable indicator of excessive ROS production in semen.
- This cost-efficient test can be a valuable tool in evaluating male infertility associated with oxidative stress.