Fertility Preservation in Pre-Pubertal Boys

Introduction: One fertility preserving strategy in you pre-pubertal boys is collection of small testicular biopsies to cryo-preserve spermatogonial stem cells (SSCs), which is now performed in many centers world-wide. From the biopsy SSCs may be propagated with intention of transplantation back into the testis to initiate spermatogenesis in adult life or to produce in vitro haploid germ cells to be used for procreation. This freez-ing method has mostly been used in boys with cancer, in which the appropriate treatment posed a risk of rendering them de-void of spermatogonial stem cells with no possibility of father-ing their own biological children. Another category of patients that runs the risk of being infertile in adulthood is boys with cryptorchidism, which is the most common defect in newborn boys’ affecting up to around 3% of all newborns. Despite that orchidopexy is nowadays performed between 6 and 12 months of age, men with a history of cryptorchidism, especially bilat-eral cryptorchidism, is exposed to a considerable risk of being infertile in adult life. We have now started to collect testicular biopsies from cryptorchid boys being operated in order to save fertility in adult life and have attempted to grow and propagate SSCs from such biopsies.We used small testicular biopsies cryopreserved from five boys with an average age of 1.5 years operated for cryptorchidism. SSC colonies were obtained by 2-step enzymatic digestion and single cells were cultured in supplemented Stempro-34 medi-um. SSC-like cell clusters were propagated by passage at least 5 times and SSCs identified by immunohistochemical and immu-nofluorescence staining plus q-PCR reaction analysis includ-ing markers like LIN-28 homolog A (LIN28A), G antigen 1 (GAGE1), promyelocytic leukemia zinc finger protein (PLZF), integrin alpha 6 (ITGA6), ubiquitin carboxy-terminal hydrolase L1 (UCHL1) and integrin beta 1 (ITGB1). We have now shown that that SSCs from infant boys potentially successfully can be in vitro propagated and may represent a fertility preservation strategy for young boys, who adversely may lose their fertility. The presentation with focus on our current results and the po-tential feasibility of this technique.