Clinical perspectives of xenografts: encapsuled chromaffin cells and pain.

Intrathecal allograft of chromaffin cells can be effectively used in replac ement of more conventional therapies for treating intractable chronic pain, such as in cancer. The efficacy of this technique depends on the ability o f those cells to produce analgesic opioids and on the immune-privileged pro perty of the central nervous system, in which rejection risks are limited. However, there are some limitations to the generalization of this new thera py, mainly due to the low number of available grafts. Thus other sources th an humans have to be considered. Here we discuss the pros and cons of the x enogeneic chromaffin cells of bovine or porcine origin. Graft immune-isolat ion, for example, by using cell encapsulation, seems to be unavoidable in s pite of the graft site. (C) 2000 Editions scientifiques et medicales Elsevi er SAS.