The Effects of Microbiota Composition on Immunosuppression Protocols in Transplantation

Immunosuppression, Kidney Transplant; Complications, Transplant Failure

Tacrolimus, Mycophenolate Mofetil, Transplantation, Kidney transplant, Calcineurin inhibitors

Solid organ transplantation is the treatment of choice for patients suffering from end-stage organ disease, including for chronic kidney failure. The implementation of effective immunosuppressive therapies has already significantly improved the prognosis for graft survival. However, these therapies are often associated with considerable inter- and intra-individual variability both in terms of response or in terms of pharmacokinetics. Innovative approaches must be considered, such as studying the involvement of intestinal microbiota in the pharmacology of these drugs. The general aim of the study is therefore to relate the variabilities observed in the pharmacology (mainly pharmacokinetics) of immunosuppressive drugs used in renal transplantation (tacrolimus and mycophenolate mofetil) and the composition of the intestinal microbiota of renal transplant patients.

Solid-organ transplantation often requires the implementation of a lifelong immunosuppressive therapy. A combination of tacrolimus (TAC), mycophenolate mofetil (MMF), together with steroids is currently used in over 60% of cases. In some patients however, these therapies are associated with high levels of variability, either in terms of response to treatments or in terms of pharmacokinetics, which remains unexplained. To address the issue, new approaches are being considered, in this study we will investigate the involvement of the intestinal microbiota in the pharmacology of these drugs. This is a particularly promising avenue for drugs with a low therapeutic index and large intra- and inter-individual pharmacokinetic variabilities such as tacrolimus and mycophenolate mofetil. Despite promising preliminary data for tacrolimus, the influence of the gut microbiota in these pharmacokinetic variabilities remains unclear, even less data are available about the involvement of the microbiota in the pharmacokinetics of mycophenolate mofetil. We expect that this study will produce additional information on the effect of immunosuppression drugs on gut microbiota, and the relationship between microbiota composition and variabilities.

Belgium