Leukocytes or white blood cells (WBCs) are present in the semen by default, though in a reduced number. If an elevated number of WBCs appears after a semen analysis (SA), we may suspect that there exists an infection. The presence of a high number of leukocytes in the semen is an abnormality known as leukospermia or pyospermia.
The various sections of this article are assembled in the following table of contents.
Leukospermia, leukocytospermia, or pyospermia is defined as the presence of more than 1 million leukocytes in 1 ml semen. As stated earlier, having Leukospermia means that there is an abnormal increased amount of leukocytes in the ejaculate.
Leukocytes, leucocytes, or white blood cells (WBCs) are cells produced by the immune system that can be found in the blood. Their main function is to help your body fight infections.
While it is normal to detect a few WBCs in the semen after performing a sperm analysis, an elevated concentration of leukocytes in a sample can compromise male fertility, as it increases the levels of oxidative stress and decreases sperm quality. In short, in can reduce a man’s sperm concentration.
The presence of leukocytes in the semen can cause temporary sterility, but rarely permanent sterility or infertility. For this reason, when leukospermia is detected, the patient needs a specific treatment to solve the infertility issues it might be causing and avoid that it becomes permanent.
Specialists calculate the amount of leukocytes in the semen per milliliter of semen following the criteria of the World Health Organization (WHO), which reference value is set at 1 million leukocytes per ml of semen. If a sample surpasses this figure, the patient will be diagnosed with pyospermia or leukospermia.
The picture above shows how a semen sample with leukocytospermia would look under the microscope. Leukocytes differ from spermatozoa because they are round-shaped structures and larger in size.
Symptoms and effects
Normally, leukospermia is asymptomatic and can only detected via a sperm analysis, often when the patient is getting started with a fertility treatment or applies to become a sperm donor.
However, sometimes the patient has certain signs and symptoms that may indicate the presence of pyospermia, including:
- Semen appears yellow in color
- Swelling in the area of the penis or groin
- Genital infections: herpes, chlamydia, gonorrhea…
- Widened or dilated veins coming from the testes
- Infrequent ejaculation
- Reduced fertility
Inflammations often cause the formation of a large amount of active-oxygen radicals, which can have negative effects on sperm, including the disruption of the integrity of their membranes, and the inhibition of sperm motility.
Causes of leukospermia
The main causes of leukospermia are infections or inflammations of the urethra, and prostatitis or inflammation of the prostate gland.
More often than not, this kind of infections come with no symptoms and are detected after performing a semen analysis, when a man is about to start an infertility treatment or being screened to become a sperm donor.
There exist other causes that can lead to an increased level of leukocytes in the semen. Various studies have revealed that sexual abstinence can have an influence, as the more time sperms remain in the epididymis, the greater the amount of macrophages and granulocytes that will be attracted by older sperm, which can cause an elevated level of leukocytes in the ejaculate.
As for men with a vasectomy, there is proof that men who have undergone this surgical intervention have a lower amount of leukocytes in their semen if compared to men who have not had a vasectomy done.
Learn more about this permanent sterilization method here: Process, pros and cons of a vasectomy.
On the other hand, men who have undergone a vasovasostomy or vasectomy reversal tend to present altered sperm parameters in the results of their semen analysis, as well as sperm dysfunction, mainly caused by high levels of Reactive Oxygen Species (ROS). There is direct link between an increase in the ROS levels and the presence of WBCs in the semen. This is not an absolute association, though.
Genital tract infection
Genital tract infections represent about 4 to 10% of the cases of male sterility. Inflammation causes leukocytes to infiltrate in the seminal fluid, which diminishes sperm motility, triggers acrosome reaction, and reduces the fertilization potential of sperms. All this makes it more difficult for the couple to achieve pregnancy.
Approximately 50% of leukocytes that infiltrate in the seminal fluid come from the prostate and the seminal vesicles where the man suffers from prostatitis (prostate infection) or seminal vesiculitis (seminal vesicle infection). Thus, infections in the accessory glands lead to an increased number of leukocytes in the ejaculate.
The following is a list of the most common microorganisms that can cause it:
- Escherichia coli or E. coli
- Klebsiella pneumonia
- Ureaplasma urealyticum
- Proteus mirabilis
- Pseudomona aeruginosa
- Staphilococcus aureus
- Mycoplasma hominis
- Enterococcus faecalis
- Morganella morganii
- Chlamydia trachomatis, and other sexually transmitted diseases (STDs).
Sperm agglutination in patients with pyospermia can very strongly indicate the presence of an E. coli infection.
Bacteria and other germs can nest in any organ of the seminal tract, thereby causing the gonads, seminal ducts, and accessory glands to become swollen. Depending on the location of the infection, it will lead to:
- infection of the testicles.
- infection of the epididymis.
- infections of both the testicles and the epididymis.
When the amount of leukocytes in the semen is above 1 million/ml after a semen analysis, a bacteriological workup that involves semen culture is required.
Samples are incubated at the adequate temperature in each culture medium. Then, the specialist evaluates the results of the semen culture, that is, whether any of the microorganisms analyzed is present.
If the result is positive, the next step is to examine the plate, and count the number of colonies. One should note that the color of a colony is an indicator of the microorganisms that form it.
Additionally, sperm staining techniques and subsequent observation under the microscope can also help the specialist to determine what is causing the infection.
The result of the semen culture should be null, as bacteria, yeast, or any other microorganism that causes infections should not be present.
Undergoing a semen culture is also recommended in men who experience any of the symptoms listed above, including pain and inflammation of the testicles, blood in the sperm (hematospermia), or changes in the color and/or odor of the ejaculate.
The presence of blood in the seminal fluid can be caused by the rupture of a small blood vessel at some point throughout the pathway of sperm, generally as a consequence of an urinary infection or trauma.
If some sort of microorganism is detected, the specialist will prescribe a treatment to erradicate the infection. Normally, the medicine of choice are antibiotics.
The type of antibiotics used and the duration of the treatment depend on the pathogen identified through the semen culture as the cause of the infection.
Aside from antibiotics, sometimes doctors prescribe painkillers or antioxidants that help diminish the levels of oxidative stress caused by the infection. This is also the treatment of choice when discovering the pathogen behind the infection has not been possible (i.e. abacterial leukocytospermia).
After the treatment, the patient should undergo another spermatobioscopy to count the number of leukocytes again. If antibiotics have worked, the amount of leukocytes in the semen would be lower. In general, if the infection is cured, all other sperm parameters improve as well, thereby boosting sperm quality.
FAQs from users
Is there a cure for leukocytospermia?
Yes. In most cases, it is possible to erradicate it by means of antibiotics. The type of antibiotics to administer is dependent on the pathogen causing the infection.
When there is no infection, and the only symptom is an inflammation, painkillers may be enough.
Can leukocytospermia cause male infertility?
Leukocytospermia is a cause of male factor infertility, but in principle there is no reason why it should lead to long-term male sterility. As explained above, in most cases, it can be treated with antibiotics and normally patients are able to recover or even improve their sperm parameters.
Is there a link between leukocytospermia and teratospermia?
Yes. Several studies have found a link between leukospermia and greater chances of suffering teratospermia, that is, having an elevated number of morphologically abnormal sperm in the ejaculate.
However, this association is not clear enough yet, as it does not apply in all cases—the amount of sperms with abnormal forms does not always increase, or not so severely as to diagnose the patient with teratozoospermia.
Also, pyospermia has been related to low sperm concentration (oligospermia) as well as alterations in sperm motility (asthenospermia).
Suggested for you
As you have just read, leukospermia can be detected by means of a semen analysis or seminogram. If you want to learn more about this diagnostic test, visit this post: What is a semen analysis and what does it involve?
Moreover, if you want to delve deeper into the causes of this pathology, we recommend you to have a look at this article: Infections and temporary sterility.