In a landmark fertility trial, a man has produced sperm after testicular tissue frozen before his childhood chemotherapy was re-transplanted 16 years later. The 27-year-old patient had the tissue removed at age 10, prior to high-dose chemotherapy for sickle cell disease. This is the first demonstration that cryopreserved prepubertal testicular tissue can restore sperm production in an adult.
The trial, led by Professor Ellen Goossens at Vrije Universiteit Brussel in collaboration with Brussels IVF, involved grafting four tissue fragments into the patient's remaining testicle and four under scrotal skin. After a year, two grafts from inside the testicle produced mature sperm, which were collected and frozen. The results, published in a preprint paper, have not yet been peer reviewed.
Treatments like chemotherapy and radiotherapy can cause infertility, but sperm preservation is not possible for prepubescent boys. The Belgian clinic began banking testicular tissue in 2002, when the field was in its infancy. Goossens noted that many more patients now have hope for biological children, as over 3,000 patients worldwide have banked tissue.
Professor Rod Mitchell, running a similar trial at the University of Edinburgh, called the finding 'proof of principle in humans'. His clinic, which has cryopreserved samples for over 1,000 UK patients, expects to carry out first transplants imminently. He emphasised the need to raise awareness, as about 200 UK patients annually could benefit.
The patient is now deciding whether to undergo further grafts or proceed with IVF. While the sperm appeared normal, researchers have yet to confirm if it can fertilise an egg.
