Is the time right for transplanting immature testicular tissue or cells to restore male fertility? Expert perspectives on clinical implementation of autotransplantation of cryopreserved testicular tissue or cells for fertility restoration.

Transplantations of cryopreserved immature testicular tissue (ITT) or spermatogonial stem cells (SSCs) represent promising approaches to restore fertility in patients with testicular tissue or cell suspension cryopreserved for fertility preservation. With over 3000 testicular samples cryopreserved globally, clinically viable and standardized protocols restoring fertility using cryopreserved testicular tissue/cells are urgently needed. Decades of research demonstrate the feasibility of immature testicular tissue transplantation (ITTT) or spermatogonial stem cell transplantation (SSCT) in animal models, including non-human primates.

Partial rejuvenation of the spermatogonial stem cell niche after gender-affirming hormone therapy in trans women.

Although the impact of gender-affirming hormone therapy (GAHT) on spermatogenesis in trans women has already been studied, data on its precise effects on the testicular environment is poor. Therefore, this study aimed to characterize, through histological and transcriptomic analysis, the spermatogonial stem cell niche of 106 trans women who underwent standardized GAHT, comprising estrogens and cyproterone acetate. A partial dedifferentiation of Sertoli cells was observed, marked by the co-expression of androgen receptor and anti-Müllerian hormone which mirrors the situation in peripubertal boys.

From spermatogonia to spermatozoa: Filling gaps in andrology at the 16th Network of Young Researchers in Andrology meeting.

The 16th Network of Young Researchers in Andrology meeting, hosted at the Sleepwell Hostel in Brussels, Belgium, was the first Network of Young Researchers in Andrology meeting as the young arm of the European Academy of Andrology. Over three days, this vibrant event provided a valuable platform for early-career researchers in andrology to present and discuss their research. With 41 attendees from 12 different countries, the meeting featured a diverse scientific program including keynote lectures from six world-leading experts, covering a broad range of topics in andrology.

Immune Checkpoint Inhibitors and Male Fertility: Should Fertility Preservation Options Be Considered before Treatment?

In recent years, immune checkpoint inhibitors (ICIs) have become a viable option for many cancer patients, including specific subgroups of pediatric patients. Despite their efficiency in treating different types of cancer, ICIs are responsible for a number of immune-related adverse events, including inflammatory toxicities, that can affect several organs. However, our knowledge of the impact of ICIs on the testis and male fertility is limited.

Empowering tomorrow's leaders: the impact of the 15th Network of Young Researchers in Andrology (NYRA) meeting on male reproductive health and interdisciplinary collaboration.

The 15th Network of Young Researchers in Andrology (NYRA) meeting, held at the Palace de Caux, Switzerland, served as a valuable platform to disseminate cutting-edge research and facilitate interactions among early-career researchers and trainees in andrology from around the world. Preceding the 22nd European Testis Workshop, the 2-day event brought together participants from a variety of countries to discuss a range of topics pertaining to men's reproductive health and biology. Specific focuses included piRNAs in mammalian reproduction, biomolecules enhancing sperm physiology, advances in in vitro spermatogenesis, reproductive strategies across species, and career development.

Gonadal development and function after immature testicular tissue banking as part of high-risk gonadotoxic treatment.

Background: Experimental fertility preservation programs have been started to safeguard the future fertility of prepubertal and pubertal males requiring high-risk gonadotoxic treatment protocols. However, long-term follow-up studies evaluating the effects on their gonadal development and function related to the testicular biopsy procedure are rather limited.

Design: This two-center follow-up study (between 2002 and 2020) evaluated the gonadal development and function of a cohort of 59 prepubertal and pubertal males who have been offered immature testicular tissue banking (TTB) prior to conventional high-risk chemo- and/or radiotherapy (HR-C/R) or conditioning therapy before hematopoietic stem cell transplantation (CT-HSCT).

Testicular Tissue Banking for Fertility Preservation in Young Boys: Which Patients Should Be Included?

Due to the growing number of young patients at risk of germ cell loss, there is a need to preserve spermatogonial stem cells for patients who are not able to bank spermatozoa. Worldwide, more and more clinics are implementing testicular tissue (TT) banking programs, making it a novel, yet indispensable, discipline in the field of fertility preservation. Previously, TT cryopreservation was predominantly offered to young cancer patients before starting gonadotoxic chemo- or radiotherapy.