Successful vitrification and autografting of baboon (Papio anubis) ovarian tissue

Andrade Amorim, Christiani [UCL] Jacobs, Sophie [UCL] Devireddy, Ram [University of Louisiana] Van Langendonckt, Anne [UCL] Vanacker, Julie [UCL] Jaeger, Jonathan [UCL] Donnez, Jacques [UCL] Dolmans, Marie-Madeleine [UCL]

In recent years, cryopreservation and transplantation of ovarian tissue has emerged as a promising alternative to restore ovarian function and fertility in cancer patients. Despite successful results obtained with conventional freezing protocols to preserve ovarian tissue, an increasing number of publications suggest that vitrification would be a better approach. The aim of this study was therefore to evaluate the efficacy of a vitrification protocol developed by our group to cryopreserve ovarian tissue. For this, we used ovaries from non-human primates in order to have an animal model close to the clinical setting. Ovarian biopsies from five adult baboons were vitrified, warmed and autografted. After five months, follicle survival, growth and function were assessed. The quality of stromal tissue and influence of the vitrification procedure on the cooling rate were also evaluated. Our results showed that after vitrification, warming and grafting, follicles were able to grow and maintain their function as illustrated by ki67, anti-Müllerian hormone and growth differentiation factor-9 immunostainings. Corpora lutea were also observed, evidencing successful ovulation in all animals. Stromal tissue quality did not appear to be negatively affected by our cryopreservation procedure, as demonstrated by vascularization and proportions of fibrotic areas, which were similar to those found in fresh ungrafted ovarian tissue. In conclusion, our results show that baboon ovarian tissue can be successfully cryopreserved using our vitrification protocol. However, before applying this technique in a clinical setting, we need to validate it by obtaining pregnancies.