Introduction 

A typical male semen contains little to no white blood cells (WBC). By little means it may contain fewer than one million white blood cells per millilitre of semen; this amount is considered to be safe for sperm to function. As soon as the WBC gets above 1 × 10⁶ /mL, it can be a sign of pyospermia.¹ It is concerning because it is not just a sign of infection or underlying conditions, but it may affect the ability of couples to bear children. It is worth noting that pyospermia significantly affects male fertility due to several factors that are linked to pyospermia. 

• Oxidative stress: when white blood cells (also called leukocytes) are in the semen, they release harmful substances called reactive oxygen species (ROS). These substances cause damage to the sperm cells' DNA, reduce their ability to move, and even affect the cell structure^2,3
• Infection: Bacteria or viruses that gain entrance into the male reproductive tract can cause conditions such as prostatitis, epididymitis, sexually transmitted diseases like chlamydia and gonorrhoea, etc., which can trigger the body's defence system, therefore increasing the number of leukocytes in the seminal fluid¹
• Inflammation: long-term inflammation in the male reproductive organ worsens WBC activities in the sperm and causes the production of reactive oxygen species¹

It is also important to note that infections, varicocele, autoimmune disorders and obstruction of the male reproductive tract are primary causes of pyospermia.¹

What are the research directions on pyospermia 

Currently, there are different choices made in treating pyospermia by addressing the contributors of pyospermia: infection and oxidative stress. These current treatments include the use of antibiotics, anti-inflammatories and lifestyle changes.¹ 

Although these treatment options are employed in pyospermia, there are still gaps, prompting the need for:

• Improved diagnosis to allow health workers to differentiate leukocytes from immature sperm cells with ease during semen analysis, which is especially important to avoid errors during diagnosis
• Tailored antioxidant treatment designed to reduce reactive oxygen species while preserving immune function^2,3
• Conduct large-scale clinical trials to help evaluate the efficacy of available treatments^2,4
• Conducting studies that look into the role of microbial imbalances in recurrent infections²

Current knowledge and barriers to pyospermia 

Causes and risk factors

The article’s introduction briefly described the causes and potential factors surrounding pyospermia. This session further classify them into 4 groups, which include:

1. Infections: these are caused by bacteria, e.g Chlamydia trachomatis, Escherichia coli or viruses, e.g human papillomavirus and herpes simplex virus, which prompt immune responses and increase white blood cells in the semen^1,4
2. Non-infectious inflammation: inflammations such as chronic prostatitis, autoimmune conditions and varicocele set off oxidative stress through reactive oxygen species^4,5
3. Lifestyle contributors: lifestyles such as smoking, alcohol, obesity, and environmental pollutants intensify the creation of reactive oxygen species and weaken the defensive nature of antioxidants^1,6
4. Structural deviations, such as the inherent abnormalities, disrupt the normal functioning of the male reproductive organs^1,4

Barriers in the current diagnosis

1. Reliance on semen analysis: Manual leukocyte counting lacks precision, often conflating immature sperm cells with leukocytes.⁷ The WHO-recommended peroxidase test detects only granulocytes, missing lymphocytes and macrophages⁷
2. Differentiating causes: Elevated leukocytes may reflect inflammation (e.g., autoimmune) rather than infection, yet standard semen cultures fail to detect atypical pathogens.^1,4 Reflexive cultures or urethral swabs post-prostatic massage improve accuracy but are underutilised⁷
3. Subjective thresholds: The diagnostic cutoff (>1 million WBCs/mL) is debated, as some studies suggest lower thresholds may still impair fertility¹

 Shortcomings in current treatments

1. Broad-spectrum antibiotics: Empiric use (e.g., doxycycline, ciprofloxacin) improves semen parameters in 40–60% of cases but shows inconsistent pregnancy rate improvements.^6,8 Overuse risks antibiotic resistance and disrupts beneficial genital microbiota^1,8
2. Lack of targeted therapies: Anti-inflammatory agents (e.g., NSAIDs) and antioxidants (e.g., vitamin E) address symptoms but not root causes like chronic inflammation or ROS imbalance^6,8
3. High recurrence rates: Up to 30% of patients experience relapse due to untreated comorbidities (e.g., varicocele) or persistent subclinical infections^4,5
4. Limited surgical options: Correction of anatomic defects (e.g., varicocelectomy) benefits only a subset, while many cases lack clear surgical targets^1,6

Advancement in diagnostics

Molecular diagnostics

PCR-based pathogen detection:

• PCR outperforms traditional semen cultures in identifying bacteria like Proteus mirabilis, which is strongly associated with infertility (p=0.002).⁹ Universal eubacterial primers detect diverse pathogens, including anaerobic species missed by cultures¹⁰
• In asymptomatic men, PCR revealed >10⁴ bacteria/mL in 66% of cases, contrasting with culture’s 27% detection rate¹⁰

Next-generation sequencing (NGS):

• Targeted NGS (tNGS) identifies pathogens, antimicrobial resistance (AMR) genes, and virulence factors simultaneously. For pneumonia, tNGS achieved 84.5% diagnostic accuracy, suggesting potential adaptation for semen analysis to detect polymicrobial infections and guide therapy¹¹

Biomarkers

Oxidative stress markers:

Elevated lipid peroxidation (LPO) and protein carbonyls (PC) correlate with poor sperm motility and morphology, while reduced antioxidants (e.g., superoxide dismutase, catalase) indicate compromised seminal defense.¹²

Inflammatory markers:

Leukocytes >1 million/mL signal inflammation, but cytokines (e.g., IL-6, TNF-α) and proteomic profiles are understudied. The presence of WBCs in the semen may suggest non-infectious inflammation, requiring wide expression patterns.¹

Imaging and AI-enhanced semen analysis

Advanced microscopy:

Immunocytochemical staining (e.g., CD45) and flow cytometry improve leukocyte quantification accuracy (>90% sensitivity) compared to manual counts or peroxidase tests (47–60% sensitivity).¹

AI integration through semen analysis:

While not yet reported in the provided studies, AI could address current limitations in differentiating leukocytes from immature sperm cells and automating semen analysis, reducing subjectivity in thresholds like the debated >1 million WBCs/mL cutoff.¹

Advancement in treatment options 

Targeted antimicrobial therapies

Microbiome-guided regimens:

• PCR and next-generation sequencing (NGS) enable precise pathogen detection (e.g., Chlamydia trachomatis, anaerobic bacteria), outperforming traditional cultures. For example, PCR identified >10⁴ bacteria/mL in 66% of asymptomatic men, versus 27% via culture¹
• Reflexive semen cultures after prostatic massage improve detection of urogenital pathogens, guiding tailored antibiotic use (e.g., doxycycline for Chlamydia, trimethoprim-sulfamethoxazole for E. coli)¹³
• Probiotics and FMT: Emerging studies suggest faecal microbiota transplantation (FMT) and probiotics (e.g., Lactobacillus) may restore genital microbiota balance, reducing recurrent infections¹⁴

Anti-inflammatory and antioxidant therapies

Specific antioxidants

• Vitamin E (400 mg/day) and N-acetylcysteine (600 mg/day) reduce lipid peroxidation and improve sperm motility. Coenzyme Q10 (200 mg/day) enhances mitochondrial function, increasing pregnancy rates in idiopathic infertility¹⁵
• Selenium (200 µg/day) and zinc (25 mg/day) restore seminal antioxidant capacity, mitigating oxidative DNA damage¹⁵

Novel anti-inflammatory agents

• Cyclooxygenase-2 inhibitors (e.g., celecoxib 200 mg/day) reduce prostaglandin-related inflammation, doubling sperm movements in trials¹
• Curcumin and resveratrol, during lab experiments was helpful in suppressing NF-κB and TNF-α which are contributors to inflammation and chronic illnesses¹⁶

Immunomodulatory treatments

1. Hormonal modulation: Androgens (e.g., testosterone) and estrogens regulate testicular immune cell activity, with low testosterone linked to elevated seminal cytokines (IL-6, TNF-α). Supplemental hormones may be effective in reducing inflammation, which is a response to injury and infection.¹⁶
2. Cytokine inhibitors: Experimental IL-1β and IL-6 blockers are being studied to dampen chronic inflammation in autoimmune-associated pyospermia¹⁶
3. Lifestyle interventions: Weight loss and smoking cessation reduce systemic inflammation, lowering seminal leukocyte counts¹⁶

Assisted reproductive techniques (ART) improvements

1. Sperm processing: Density gradient centrifugation with antioxidants (e.g., vitamin C) removes leukocytes while preserving sperm viability¹⁵
2. ICSI advancements: Intracytoplasmic morphologically selected sperm injection (IMSI) selects sperm with minimal DNA fragmentation, improving embryo quality in pyospermia patients¹
3. Combined therapies: Pre-ART antibiotic courses (e.g., 4-week doxycycline) resolve infections, enhancing fertilisation rates.¹ Antioxidant pretreatment (2–3 months) further reduces oxidative stress during IVF¹⁵

Summary

Pyospermia needs immediate medical attention upon detection as it may indicate underlying issues and can lead to male infertility. This article reflects current knowledge and treatment options available for managing pyospermia and captures research areas to explore towards providing more effective and efficient therapies for pyospermia.