B.C.P. Jansen Institute, University of Amsterdam, Amsterdam, The Netherlands

In a patient with Fabry's disease who had undergone kidney transplantation to correct uremia, the neutral glycosphingolipids and alpha-galactosidase activity have been measured in plasma and urine and, 9 months later, after the death of the patient, in autopsy material. After transplantation, there was no significant increase in alpha-galactosidase activity in plasma; the activity found never exceeded 3% of the mean control value. A striking parallelism was found during the follow-up period in the increase and decrease of trihexosylceramide and globoside and also of glucosylceramide and dihexosylceramide. The alpha-galactosidase activity in spleen and liver was as low as that observed in untreated Fabry hemizygotes. These data and those obtained from autopsy material provide evidence that renal transplantation does not lead to a specific enzymic breakdown of trihexosylceramide in Fabry patients. However, no trihexosylceramide accumulation was observed in the transplanted kidney.