A study revealed associations between human papillomavirus infection in men and alterations in sperm characteristics, particularly with high-risk genotypes.
Olivera et al conducted a study of 205 adult males attending a urology clinic in Argentina from 2018 to 2021. Published in Frontiers in Cellular and Infection Microbiology, the research detected human papillomavirus (HPV) in 19% (39 of 205) of semen samples. High-risk (HR) HPV infections were more common, with HPV-16 being the most frequent genotype (59.2%), followed by the low-risk (LR) genotype HPV-6 (14.8%). The median age of participants was 35 years (95% confidence interval [CI] = 34-36 years).
Key Findings
No significant differences were observed in routine sperm parameters between the HR-HPV, LR-HPV, and control groups.
HR-HPV+ individuals showed significantly higher levels of sperm necrosis compared to LR-HPV+ or control individuals (HR-HPV: 15.42 ± 16.37%, LR-HPV: 4.17 ± 2.48%, control: 4.29 ± 3.56%).
HR-HPV+ patients exhibited significantly higher frequencies of reactive oxygen species (ROS)-positive spermatozoa (84.63 ± 18.65%) compared to LR-HPV+ (57.86 ± 17.07%) or control individuals (50.01 ± 29.02%).
HR-HPV+ patients showed reduced semen leukocytes and inflammatory cytokines compared to controls. CD45-positive cells (x10^5/mL) were significantly lower in HR-HPV+ patients (1.83 ± 2.95) compared to controls (6.75 ± 10.3, p=0.019).
HR-HPV+ patients showed decreased IL-6 (52.43 ± 88.03 pg/mL) and IL-1β (3.61 ± 3.83 pg/mL) levels compared to controls (IL-6: 123.4 ± 135.6 pg/mL, p=0.028; IL-1β: 7.51 ± 5.61 pg/mL, p=0.001). LR-HPV+ patients exhibited increased IL-1β (20.11 ± 13.67 pg/mL, p=0.007) and IL-10 (20.47 ± 18.82 pg/mL, p=0.029) levels compared to controls and HR-HPV+ patients, respectively.
Study Methods and Further Findings
The study employed various techniques, including polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) for HPV detection and genotyping, flow cytometry for sperm apoptosis/necrosis and ROS assessment, and enzyme-linked immunosorbent assay for cytokine quantification. PCR-RFLP used seven restriction enzymes (BamHI, DdeI, HaeIII, HinfI, PstI, RsaI, SauIIIA) for HPV genotyping. Flow cytometry was performed using a FACS Canto II cytometer and analyzed with FlowJo 7.6 software.
Participants were divided into three groups: a control group (negative for all analyzed uropathogens), HR-HPV patients (positive for intermediate– or high–oncogenic risk HPV genotypes), and LR-HPV patients (positive for low oncogenic–risk HPV genotypes).
Detailed sperm quality parameters (mean ± standard deviation [SD]) included:
- Ejaculate volume (mL): Control: 3.21 ± 1.48, HR-HPV: 3.06 ± 1.32, LR-HPV: 3.37 ± 1.59
- Sperm concentration (10^6/mL): Control: 67.95 ± 53.36, HR-HPV: 64.67 ± 45.99, LR-HPV: 52.83 ± 36.42
- Total sperm motility (%): Control: 57.26 ± 17.65, HR-HPV: 55.30 ± 19.37, LR-HPV: 53.00 ± 16.64
- Progressive sperm motility (%): Control: 47.79 ± 17.72, HR-HPV: 47.15 ± 19.59, LR-HPV: 45.83 ± 16.85
- Normal sperm morphology (%): Control: 5.79 ± 3.07, HR-HPV: 5.55 ± 2.82, LR-HPV: 4.67 ± 2.25.
The researchers also analyzed the impact of HR-HPV infection alone or in combination with other uropathogens. Both HR-HPV+ groups (with and without coinfections) showed increased sperm ROS production and necrosis in the absence of semen inflammation. Necrotic spermatozoa were significantly higher in HR-HPV+ patients with a coinfection compared to controls (p=0.033), while HR-HPV+ patients without a coinfection showed a trend towards higher levels (p=0.071).
This study provided data on the effects of HPV infection on male reproductive health, highlighting associations between HR-HPV infections and increased sperm necrosis and oxidative stress, despite no significant alterations in routine sperm quality parameters.
The authors declared that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
