Differential leucocyte detection by flow cytometry improves the diagnosis of genital tract inflammation and identifies macrophages as proinflammatory cytokine-producing cells in human semen

Evaluation and management of male genital tract infections in the setting of male infertility: an updated review

PURPOSE OF REVIEW

Male infertility may be secondary to male genital tract infection (MGTI) in an estimated 15% of cases. In the absence of overt clinical signs, evaluation for MGTI beyond semen analysis is not well established. Therefore, we review the literature on the evaluation and management of MGTI in the setting of male infertility.

RECENT FINDINGS

A set of international guidelines recommends semen culture and PCR testing, but the significance of positive results remains unclear. Clinical trials evaluating anti-inflammatory or antibiotic treatment report improvements in sperm parameters and leukocytospermia, but data on the effect on conception rates are lacking. Human papillomavirus (HPV) and the novel coronavirus (SARS-CoV-2) have been associated with poor semen parameters and decreased conception rates.

SUMMARY

The finding of leukocytospermia on semen analysis prompts further evaluation for MGTI, including focused physical examination. The role of routine semen culture is controversial. Treatment options include anti-inflammatories; frequent ejaculation; and antibiotics, which should not be used in the absence of symptoms or microbiological infection. SARS-CoV-2 represents a subacute threat to fertility that should be screened for in the reproductive history along with HPV and other viruses.

The myeloid mineralocorticoid receptor regulates dermal angiogenesis and inflammation in glucocorticoid-induced impaired wound healing

BACKGROUND AND PURPOSE

Delayed wound healing is among the deleterious consequences of over-activation of the mineralocorticoid receptor (MR) induced by topical dermocorticoids. The role of dermal inflammation and angiogenesis in the benefits of MR blockade is unknown.

EXPERIMENTAL APPROACH

Skin wounds were made on C57Bl6 mice after topical pretreatment with the dermocorticoid clobetasol. The impact of topical MR blockade by canrenoate on inflammation, angiogenesis, and the wound macrophage phenotype was analysed 5 days post-wounding. Similar experiments were conducted on mice with genetic deletion of the MR in myeloid cells.

KEY RESULTS

Topical inhibition of the MR with canrenoate improved delayed wound healing through the resolution of prolonged inflammation in glucocorticoid-pretreated mouse skin. This effect was associated with a higher ratio of anti-inflammatory macrophages versus pro-inflammatory macrophages in wounds treated by canrenoate. Furthermore, MR blockade led to upregulated expression of pro-angiogenic factors and improved impaired angiogenesis in wounds of glucocorticoid-pretreated skin. Finally, deletion of MR expression by myeloid cells reproduced the benefits of topical pharmacological MR blockade.

CONCLUSION AND IMPLICATIONS

Topical MR antagonism facilitates the switching of macrophages towards an anti-inflammatory phenotype, which improves prolonged inflammation and induces angiogenesis to accelerate wound healing delayed by glucocorticoid treatment.

Pyospermia: background and controversies

Pyospermia (or leukocytospermia) is suspected based on the presence of >1 × 10⁶ round cells/mL of ejaculate and diagnosed using peroxidase stain revealing >1 × 10⁶ white blood cells/mL. The presence of white blood cells is a concern for overt infections or excessive inflammation, both of which have been postulated to negatively impact bulk semen parameters and fertilization capability. The threshold for pyospermia has been debated upon in the literature, as has the optimal treatment method. In the absence of clinical infectious symptoms, it appears that antibiotics, anti-inflammatory agents, and/or frequent ejaculation may improve bulk semen parameters in men with pyospermia. Further research is needed to adequately assess the effect of these methods on pregnancy and live birth outcomes, especially among couples attempting natural conception compared to those attempting intrauterine insemination or in vitro fertilization.

Monocyte-derived extracellular trap (MET) formation induces aggregation and affects motility of human spermatozoa in vitro

The presence of bacteria and/or leukocytes can alter semen quality resulting in low sperm quality and infertility. Inflammation or infection increases the numbers of PMN or macrophages/monocytes in male genital tract. Release of extracellular traps (ETs) by leukocytes has been recognized as a novel mechanism of early host innate immunity, in response to invasive pathogens. This is the first work that evaluated the mechanism of triggered ETs in monocytes co-incubated with spermatozoa or bacteria and the effect on sperm function. Selected spermatozoa and human monocytes isolated from peripheral blood were obtained by healthy donors. Two experimental models were developed, one aseptic (non-infectious) incubating spermatozoa and monocytes, and septic models (infectious) incubating spermatozoa with monocytes and uropathogenic Escherichia coli (E. coli). ETs of monocytes (METs) (DNA, global histone and citrullinated histones) were visualized by scanning electron microscopy (SEM) and immunofluorescence analyses. Progressive motility was performed at 0, 10, 30, 60, and 180 min after co-incubation with CASA system. SEM- and immunofluorescence-analyses revealed human spermatozoa alone or in the presence of E. coli as strong inducers METs. In aseptic model, the motility decreased to 65.2 ± 3.5% at 10 min of incubation and 29.3 ± 3.3% at 30 min (p < 0.001). In septic model, motility decreased to 44.5 ± 5.9% (10 min) and 12.7 ± 2.2% (30 min) (p < 0.001). MET-derived small spermatozoa aggregations were observed in both models. METs might physically block spermatozoa and decrease motility after a brief contact. This may impair male fertility, especially in patients with genital tract infections or chronic inflammation. Abbreviations: PMN: polymorphonuclear; ETs: extracellular traps; E. coli: Escherichia coli; METs: ETs of monocytes; SEM: scanning electron microscopy; NE: neutrophil elastase; MPO: myeloperoxidase; MAGI: male accessory gland infection; PBMC: peripheral blood mononuclear cells; RT: room temperature; CFU: colony forming units; CASA: computer-aided sperm analysis; H4Cit3: histone H4 citrullinated 3.

Evaluation of the Sysmex UF-1000i system as an alternative for the screening of genital tract inflammation in male infertility patients

The number of white blood cell (WBC) in semen is an important indicator of genital tract inflammation in male infertility. The peroxidase assay is the recommended reference method for seminal WBC counting. However, it is time-consuming and may cause relatively heavy workload in daily routine. Meanwhile, the main component in the reagent of peroxidase test is harmful to human and the environment. In this study, we evaluated the analytical performance of the Sysmex UF-1000i that is a urine flow cytometer as a screening tool for genital tract infection in male infertility patients through the counting of seminal WBC. We examined 143 semen samples and compared the results of UF-1000i and manual microscopy. The intra-assay variability, stability and linearity studies were performed. The intravariability (CV %) of seminal WBC count by Sysmex UF-1000i was 2.34%-9.65%. The method of UF-1000i displayed a good agreement with the reference assay of manual microscopy, and the r value for correlation of seminal WBC count between UF-1000i and manual microscopy was over 0.999 (p < 0.001). The Sysmex UF-1000i is capable of producing reliable seminal WBC count consistent with that obtained by manual microscopy. It is a suitable alternative to the manual microscopy, thus reduces the workload.

Downregulation of DJ-1 Fails to Protect Mitochondrial Complex I Subunit NDUFS3 in the Testes and Contributes to the Asthenozoospermia

Asthenozoospermia (AS), an important cause of male infertility, is characterized by reduced sperm motility. Among the aetiologies of AS, inflammation seems to be the main cause. DJ-1, a conserved protein product of the PARK7 gene, is associated with male infertility and plays a role in oxidative stress and inflammation. Although our previous studies showed that a reduction in DJ-1 was accompanied by mitochondrial dysfunction in the sperm of patients with AS, the specific mechanism underlying this association remained unclear. In this study, we found that compared to the patients without AS, the expression of mitochondrial protein nicotinamide adenine dinucleotide dehydrogenase (ubiquinone) Fe-S protein 3 (NDUFS3) was also significantly decreased in the sperm of patients with AS. Similarly, decreased expression of DJ-1 and NDUFS3 and reduced mitochondria complex I activity were evident in a rat model of AS. Moreover, we showed that the interaction between DJ-1 and NDUFS3 in rat testes was weakened by ORN treatment. These results suggest that the impaired mitochondrial activity could be due to the broken interaction between DJ-1 and NDUFS3 and that downregulation of DJ-1 in sperm and testes contributes to AS pathogenesis.

Urogenital Infection as a Risk Factor for Male Infertility

BACKGROUND

Infections of the genital tract are considered common causes of male fertility disorders, with a prevalence of 6-10%. Most of the affected men are asymptomatic. The diagnostic evaluation is based mainly on laboratory testing. Inconsistent diagnostic criteria have been applied to date, and this may explain the controversial debate about the role of infection and inflammation in the genital tract as a cause of infertility. The risk of an irreversible fertility disorder should not be underestimated.

METHODS

This review is based on pertinent publications retrieved by a selective literature search in PubMed, including guidelines from Germany and abroad and systematic review articles.

RESULTS

The main causes of inflammatory disease of the male genital tract are ascending sexually transmitted infections (STIs) and uropathogens. Chronic prostatitis has no more than a limited influence on ejaculate variables. By contrast, approximately 10% of men who have had acute epididymitis develop persistent azoospermia thereafter, and 30% have oligozoospermia. Obstruction of the excurrent ducts can ensue, as can post-infectious disturbances of spermatogenesis. The differential diagnostic evaluation includes the determination of testicular volumes, hormone concentrations, and ejaculate variables. Epidemiological data are lacking with regard to infertility after primary orchitis of infectious origin; however, up to 25% of testicular biopsies obtained from infertile men reveal focal inflammatory reactions. Multiple studies have suggested a deleterious effect of leukocytes and inflammatory mediators on sperm para - meters. On the other hand, the clinical significance of bacteriospermia remains unclear.

CONCLUSION

Any suspicion of an infectious or inflammatory disease in the male genital tract should prompt a systematic diagnostic evaluation and appropriate treatment. For patients with obstructive azoospermia, the etiology and site of the obstruction determine the surgical approach to be taken. In the near future, the elucidation of underlying pathophysiological mechanisms and the identification of suitable biomarkers may enable new strategies for conservative treatment.

NT-proCNP as a new indicator of asthenozoospermia

PURPOSE

C-type natriuretic peptide (CNP) is a proinflammatory peptide. The highest concentration of CNP is found in male reproductive organs. This study aims to analyze the role of N-terminal C-type natriuretic propeptide (NT-proCNP) as a new indicator of asthenozoospermia.

MATERIAL/METHODS

Semen was collected after 3-5 days of sexual abstinence from 86 men. The participants were between 25 and 38 years old, 51 of which had asthenozoospermia and 35 of which had normal sperm motility. Semen was analyzed for the concentrations of NT-proCNP, spermatozoa, percentages of live sperm, and sperm exhibiting a specific type of movement. The laboratory tests and analyses were performed using accepted methods and under appropriate conditions.

RESULTS

A significant difference in the concentration and motility of spermatozoa was observed between the focus and control groups. The concentration of spermatozoa in the focus group was significantly lower than in the control group (median: 38.5 vs. 69.8mln/ml [p=0.016] respectively). The progressive motility of spermatozoa demonstrated a significantly lower performance in the focus group than in the control group (median: 10.4% vs. 45% respectively). The concentration of NT-proCNP was significantly higher in the focus group (median: 29.1 vs. 17.9pmol/l; p<0.001). The Area under the Receiver Operating Characteristic (AUROC) curve for the concentration of NT-proCNP - as an indicator of asthenozoospermia - was 0.733. Participants with a concentration of NT-proCNP higher than 28.8pmol/l had asthenozoospermia with 52.9% sensitivity and 94.3% specificity.

CONCLUSIONS

NT-proCNP - an indicator of inflammatory reaction - should be evaluated as an indicator of asthenozoospermia.