Is there a risk of prion disease after the administration of urinary-derived gonadotrophins?

Concern has been raised recently about the possibility of prion proteins appearing in the urine of animals and, possibly, humans affected by prion disease [scrapie, bovine spongiform encephalopathy (BSE) and Creutzfeldt Jakob disease (CJD)]. A debate has started in which the suggestion has been made that the purification of human urine for the provision of gonadotrophins should be discontinued. The alternative would be to use recombinantly-derived gonadotrophin preparations. The recombinant products, however, rely upon bovine serum during the cell culture process and could potentially also be exposed to abnormal prion proteins. It is reassuring that the different types of gonadotrophin preparations that are currently available are produced with either urine or bovine serum that is sourced from countries that at the present time appear to be free of BSE and new variant CJD. We can therefore be reassured that the gonadotrophins that we use therapeutically appear to be equally safe.