Male Fertility · Male Factor Causes
Abstract
Immune checkpoint inhibitors (ICIs), namely, anti-cytotoxic T lymphocyte-associated protein 4 (CTLA-4) monoclonal antibody Ipilimumab and anti- and programmed cell death 1 (PD-1) monoclonal antibodies Nivolumab, and Pembrolizumab, have improved the treatment outcomes for many other cancer types. However, their impact on fertility remains under-explored.
The possible direct effects of ICIs on human sperm was investigated. Spermatozoa from ten normozoospermic donors were exposed to Ipilimumab, Nivolumab, or Pembrolizumab at concentrations ranging from 1 to 100 ng/mL. Sperm motility was assessed through standard laboratory process. Cell viability and apoptosis markers were evaluated by flow-cytometry using fluorescent Annexin-V probe and Terminal Uridine Nick-End Label (TUNEL) assays. Protein-A-purified therapeutic antibodies (IgG) were also evaluated.
Spermatozoa had high PD-1 (>99%) and negligible CTLA-4 expression. Exposure to ICIs, was associated with a concentration-dependent impairment of sperm motility, noticeable for Pembrolizumab and Ipilimumab since 10 ng/mL, and for Nivolumab since 100 ng/mL. However, no significant effect on cell apoptosis or viability was shown. Purified IgG from ICIs maintained the adverse effect on cell motility without affecting viability.
ICIs, specifically Pembrolizumab, Nivolumab, and Ipilimumab, adversely affect human sperm motility in vitro. Further research is required to understand the underlying mechanisms and clinical implications.
Topics
By this author
Preimplantation genetic testing for male factor infertility: lights and shadows
Mazzilli R et al., 2026 · Journal of endocrinological investigation
Male factor could contribute, alone or in combination with female factor, to the inability to conceive in a couple in more than half of cases. The effect of male factor infertility (MFI) on embryological assisted reproductive technology (ART) outcomes remains an ongoing discussion. to evaluate the impact of MFI on embryo aneuploidy rates, to better understand the role and possible indication for Preimplantation genetic testing for aneuploidies (PGT-A), considering the role of sperm characteristics, paternal age, sperm DNA fragmentation and sperm aneuploidies. this narrative review included all available articles, published up to January 2026. Available evidence, often based on heterogeneous and old-fashioned methodologies, suggests that MFI may impair embryonic development, particularly in terms of fertilization rate and blastulation rate, more than embryo euploidy; however, a comprehensive evaluation of MFI should be integrated into clinical practice in the context of couple infertility, to also optimize the efficiency and outcomes of ART. Promising results emerged from sperm DNA fragmentation as a tool to predict embryo euploidy, but further investigations involving larger sample sizes and improved standardization are required.
Pathophysiology-Based Classification of Male Infertility: Evidence from an 800-patient Prospective Cohort
Grande G et al., 2026 · The Journal of clinical endocrinology and metabolism · Free to read
Male factor infertility (MFI) is frequently labelled idiopathic when evaluation relies primarily on semen analysis, potentially overlooking endocrine and pathophysiological mechanisms relevant for targeted management. To phenotypically define MFI and develop a pathophysiology-based classification aimed at reducing idiopathic infertility following comprehensive evaluation. Prospective monocentric cohort study conducted at a tertiary referral academic centre. Eight hundred male partners of infertile couples evaluated between October 2024 and January 2026 after exclusion of isolated female factor infertility. Prevalence of MFI categories, hormonal patterns across phenotypes, and proportion of idiopathic infertility after comprehensive work-up. All patients underwent standardized clinical evaluation, hormonal assessment (total testosterone, FSH, LH), testicular ultrasound, and complete semen analysis. Microbiological testing, transrectal ultrasound, and genetic analyses were performed according to guidelines. Primary spermatogenic failure was the most prevalent category (56.0%), followed by infection/inflammation (22.4%) and hypogonadotropic hypogonadism (8.5%). Idiopathic infertility was identified in only 5.3% of cases. Distinct endocrine profiles were observed, with high-FSH spermatogenic failure representing the dominant phenotype. Comprehensive phenotyping markedly reduces the proportion of patients classified as having idiopathic infertility and identifies clinically relevant subgroups. This prospective study provides validation of a pathophysiology-based classification and supports a shift toward endocrine-integrated diagnostic strategies in male infertility, with potential implications for targeted management.
Beyond semen analysis: in men with normal semen parameters telomere attrition and oxidative imbalance distinguish those fertile from those with infertility
Rocca MS et al., 2026 · Journal of translational medicine · Free to read
Standard semen analysis has little prognostic value in distinguishing fertile from infertile men. Furthermore, in men with semen parameters within the reference ranges, it cannot distinguish fertile men from infertile men, i.e. partners of couples with idiopathic infertility. Oxidative stress, mitochondrial dysfunction, sperm telomere shortening, and DNA fragmentation have been proposed as contributors to impaired male fertility. However, these biomarkers have not been evaluated as a whole in subjects with normal semen parameters, partners of fertile and infertile couples. To characterise a multidimensional panel of sperm biomarkers-including sperm telomere length (STL), mitochondrial DNA copy number (mtDNAcn), reactive oxygen species (ROS), lipid peroxidation (LP), sperm chromatin dispersion (SCD), and respiratory control ratio (RCR)-and to identify whether these parameters might discriminate, in men with normal semen parameters, infertile men from fertile controls. A total of 150 men with semen parameters within the normal ranges were enrolled: 47 male partners of couples with idiopathic infertility and 103 fertile controls. STL and mtDNAcn were quantified by qPCR; ROS were assessed using OxiSperm®II with semiquantitative imaging; LP was measured spectrophotometrically in seminal plasma; SCD was used to determine DNA fragmentation; and mitochondrial function was evaluated by oxygen consumption and RCR. Correlations between biomarkers and semen parameters were analysed using Pearson or Spearman coefficients, and intergroup comparisons were adjusted for age. Semen parameters did not differ significantly between male partners of fertile and infertile couples. compared to men of fertile couples, men of infertile couples exhibited significantly shorter STL (0.57 ± 0.59 vs 1.21 ± 1.13, p_adj = 0.001) and higher oxidative stress, with both ROS (8300.9 ± 4214.8 vs 6555.3 ± 3394.3, p_adj = 0.027) and LP (88.33 ± 55.50 vs 40.29 ± 46.98, p_adj < 0.001) markedly elevated. mtDNAcn, SCD, and RCR showed no difference between the groups. Across the entire cohort, STL correlated negatively with ROS and LP and positively with RCR. ROS correlated negatively with total sperm count, motility and RCR, and positively with LP. LP displayed the strongest pattern of associations, correlating negatively with concentration, total count, motility, STL and RCR, and positively with age and volume. Among men with normal semen analysis, partners of couples with idiopathic infertility exhibit a distinct sperm molecular profile characterised by telomere shortening and oxidative imbalance. STL, ROS and LP emerged as age-independent biomarkers associated with infertility status and showed promising discriminatory ability in this cohort, supporting their integration as second-level tests to complement routine semen analysis in cases of normozoospermia.
Neoplastic Risk in Patients With Klinefelter Syndrome
Graziani A et al., 2026 · Andrology · Free to read
Besides gonadal involvement (hypogonadism, male factor infertility, and testicular hypotrophy), patients with Klinefelter syndrome (KS) may suffer from several extra-gonadic complications, including neoplastic events. The aim of this review is to summarize all major clinical evidence dealing with the association between KS and neoplastic diseases and provide practical suggestions for the management of patients with KS regarding neoplastic risk. This narrative review was conducted through a comprehensive search of the PubMed database, using combinations of the following keywords: "Klinefelter syndrome," "cancer," "neoplasm," "breast cancer," "germ cell tumor," "lymphoma," and "testosterone replacement therapy". KS is associated with a higher risk of breast cancer and mediastinal germ cell tumors and an apparent higher risk of hematological malignancies, in particular non-Hodgkin lymphoma and leukemia. Evidence on testicular cancer is limited, with no clear increase in risk attributable to KS, while prostate cancer has a lower risk and lower mortality rate. Given the complexity of the syndrome and the limited available evidence, regular clinical follow-up with targeted investigations when clinically indicated may facilitate early diagnosis and management of associated comorbidities.
Related research
Combined evaluation of prolactin-induced peptide (PIP) and extracellular signal-regulated kinase (ERK) as new sperm biomarkers of FSH treatment efficacy in normogonadotropic idiopathic infertile men
Mancini F et al., 2024 · Journal of endocrinological investigation
Nearly, 40% of the causes of male infertility remain idiopathic. The only suggested treatment in idiopathic oligo- and/or asthenozoospermia in normogonadotropic patients is the FSH. In the current clinical practice, efficacy is exclusively assessable through semen analysis after 3 months of treatment. No molecular markers of treatment efficacy are appliable in clinical practice. The aim of the present work is to evaluate the combination of extracellular signal regulated kinase (ERK) 1 and 2 and prolactin inducible peptide (PIP) as potential markers of idiopathic infertility and FSH treatment efficacy. Western blot and confocal microscopy were performed to analyze the modulation of PIP and ERK1/2 in idiopathic infertile patients (IIP) sperm cells. Taking advantage of mass spectrometry analysis, we identified these proteins unequivocally in sperm cells. We demonstrated a significant decrease of both PIP protein and of ERK1/2 levels in spermatozoa obtained from IIP in comparison to healthy fertile patients (HFP). Conversely, we reported a significant increase of these markers comparing infertile patients before and after 3 months of FSH treatment. Importantly, this correlated with an increase in total number of sperm and sperm motility after FSH treatment. Finally, we identified of PIP and ERK2 proteins in sperm samples by proteomic analysis. The combined evaluation of ERK1/2 and PIP proteins might represent a useful molecular marker to tailor FSH treatment in the management of male normogonadotropic idiopathic infertility.
Survey of Long-Term Experiences of Sperm Cryopreservation in Oncological and Non-Oncological Patients: Usage and Reproductive Outcomes of a Large Monocentric Cohort
Lackamp N et al., 2021 · Frontiers in oncology · Free full text on PubMed Central
Progress in oncological treatment has led to an improved long-term survival of young male cancer patients over the last decades. However, standard cancer treatments frequently implicate fertility-damaging potential. Cryopreservation of sperm is the current standard option to preserve patient's fertility after treatment, yet long-term data on usage and reproductive experiences is still limited. Natural fertility after treatment and especially in relation to the type of treatment has been poorly analyzed so far. Therefore, we performed a retrospective survey including male patients with an indication for gonadotoxic treatment who cryopreserved reproductive material at our institution between 1994 and 2017. Study questionnaires regarding treatment, material usage, and reproductive outcomes were sent to eligible patients. Additionally, semen analyses of study participants from the time of cryopreservation were evaluated. A total of 99 patients were included in the study. Respondents' median age was 38.0 years. Most frequent diagnoses were testicular cancer (29.3%) and lymphoma (26.3%). A further 8.1% suffered from autoimmune diseases. Testicular cancer patients had a significantly lower pre-treatment median sperm concentration (18.0 million/ml) compared to non-testicular cancer patients (54.2 million/ml). Until November 2020, the determined sperm usage and cumulative live-birth rate per couple were 17.2% and 58.8%, respectively. Most sperm users received treatments with high (40.0%) or intermediate (33.3%) gonadotoxic potential. 20.7% of all patients reported to had fathered at least one naturally conceived child after treatment, this being the case especially if they had been treated with less or potentially gonadotoxic therapies. In conclusion, our findings emphasize the importance of sperm cryopreservation in the context of male fertility preservation. Furthermore, they indicate that the gonadotoxic potential of patients' treatments could represent a predictive factor for sperm usage.
Photobiomodulation with 810 nm Wavelengths Improves Human Sperms' Motility and Viability In Vitro
Safian F et al., 2020 · Photobiomodulation, photomedicine, and laser surgery
Enhanced sperm motility is necessary for the successful journey of sperm inside the female genital tract, successful fertilization, and the increased chance of pregnancy. We investigated the impact of red and near-infrared (NIR) ranges of photobiomodulation (PBM) alone and together on fresh human sperm to validate an optimized PBM protocol that would maximize sperm motility and viability in vitro. We randomly divided 30 normal human semen samples into 3 different PBM protocols (red, NIR, and red+NIR lasers). Each sample was divided into four subparts, one control group sample and three experimental group samples. Each experimental group received one of the PBM protocols (red, NIR, or red+NIR). Each protocol was adjusted to three energy densities (0.6, 1.2, and 2.4 J/cm2). After exposure to the selected protocol, we determined the percentage of either viable or progressive sperm motility (PSM) and measured the DNA Fragmentation Index (DFI). The NIR and red+NIR lasers at 2.4 J/cm2 energy density significantly increased PSM after 60 min compared with the control groups [least significant difference (LSD) test, p = 0.023 and p = 0.04, respectively]. Samples treated with the red laser at 0.6 J/cm2 had significantly decreased viability compared with the control group (LSD test, p = 0.003). Samples treated with the red+NIR lasers had significantly decreased viability at 0.6 J/cm2 (p = 0.003), 1.2 J/cm2 (p = 0.001), and 2.4 J/cm2 (p = 0.04) energy densities when compared with the control groups. The NIR laser resulted in no significant difference in sperm viability between the control and experimental groups. At 120 min after exposure, treatment with the red+NIR and red lasers at 2.4 J/cm2 density significantly increased DFI compared to the control groups (LSD test, p = 0.000, p = 0.007). In this study, sperm motility, viability, and DFI data confirmed the superiority of the NIR laser at 0.6 J/cm2 energy density compared with the red and red+NIR PBM protocols.
Infertility in Men: Advances towards a Comprehensive and Integrative Strategy for Precision Theranostics
Assidi M, 2022 · Cells · Free full text on PubMed Central
Male infertility is an increasing and serious medical concern, though the mechanism remains poorly understood. Impaired male reproductive function affects approximately half of infertile couples worldwide. Multiple factors related to the environment, genetics, age, and comorbidities have been associated with impaired sperm function. Present-day clinicians rely primarily on standard semen analysis to diagnose male reproductive potential and develop treatment strategies. To address sperm quality assessment bias and enhance analysis accuracy, the World Health Organization (WHO) has recommended standardized sperm testing; however, conventional diagnostic and therapeutic options for male infertility, including physical examination and semen standard analysis, remain ineffective in relieving the associated social burden. Instead, assisted reproductive techniques are becoming the primary therapeutic approach. In the post-genomic era, multiomics technologies that deeply interrogate the genome, transcriptome, proteome, and/or the epigenome, even at single-cell level, besides the breakthroughs in robotic surgery, stem cell therapy, and big data, offer promises towards solving semen quality deterioration and male factor infertility. This review highlights the complex etiology of male infertility, especially the roles of lifestyle and environmental factors, and discusses advanced technologies/methodologies used in characterizing its pathophysiology. A comprehensive combination of these innovative approaches in a global and multi-centric setting and fulfilling the suitable ethical consent could ensure optimal reproductive and developmental outcomes. These combinatorial approaches should allow for the development of diagnostic markers, molecular stratification classes, and personalized treatment strategies. Since lifestyle choices and environmental factors influence male fertility, their integration in any comprehensive approach is required for safe, proactive, cost-effective, and noninvasive precision male infertility theranostics that are affordable, accessible, and facilitate couples realizing their procreation dream.