T Böhler

FTY 720A mediates reduction of lymphocyte counts in human renal allograft recipients by an apoptosis-independent mechanism

Abstract The novel immunosuppressive compound FTY 720A posseses a mode of action which is different from all other immunosuppressive drugs. The most prominent feature is a reversible decrease in peripheral lymphocyte counts observed in animal experiments. We investigated in the first human trial (phase 1) whether FTY 720A induces apoptosis of peripheral blood mononuclear cells (PBMC) in stable renal allograft recipients. Monitoring of lymphocyte counts revealed a significant and dose‐dependent decrease within 6 h post‐FTY 720A dose: placebo 5.1%; 0.25 mg 36.4%; 0.5 mg 40.8%; 0.75 mg 39.4%; 1 mg 45.8%; 2 mg 67.2%; 3.5 mg 64.9%. PBMC apoptosis rates did not change, as determined before intake of FTY 720A and 2 h, 6 h, 24 h and 96 h post‐FTY 720A dose. We detected no significant difference in apoptosis rates between patients who received placebo or FTY 720A. However, in vitro experiments showed that high concentrations of FTY 720 A induced apoptosis in human PBMC.

The influence of age on outcome after renal transplantation

The influence of donor age and recipient age on outcome after renal transplantation has been investigated in numerous studies. There is some evidence that patient survival in elderly patients who receive a transplant is significantly higher compared with those, who remain on dialysis. In general, patient survival after renal transplantation is mainly dependent on recipient age and on comorbid conditions. Concerning graft survival, most studies conclude that the survival of kidneys taken from older donors (> 50 years) and very young donors (< 5 years) is reduced. Graft survival was also found to be reduced in very young recipients (< 5 years). Functional graft survival proved to be better in older recipients (> 50 years) as compared to younger recipients, due to a reduced immunologic response capability. Actual graft survival however, where cases of death with functioning graft are included, is fairly equal in both populations. The question, whether the age difference between donor and recipient has an influence on graft survival, needs to be further investigated. In conclusion, donor and recipient age are important risk factors, which may influence outcome after renal transplantation and therefore should be considered carefully.