Preservation of renal function during maintenance therapy with cyclosporine

Diltiazem as a cyclosporine A-sparing agent in heart transplantation: Benefits beyond dose reduction

Diltiazem (DZ) is widely prescribed in transplant recipients because of its drug-drug interactions with calcineurin inhibitors (CNI). However, these interactions have been primarily investigated in renal transplantation, and data regarding the long-term efficacy and safety of DZ in orthotopic heart transplantation (OHT) are still sparse. Our study aimed to elucidate the extent to which the co-prescription of DZ reduces the dose required to maintain adequate blood levels of cyclosporine A (CsA) and the resulting effect on morbidity and mortality in OHT recipients. We performed a retrospective single-center analysis of OHT recipients on a long-term immunosuppressive regimen based on CsA and mycophenolate mofetil (MMF). The study population consisted of 95 adult OHT recipients with a mean follow-up of 15.8 ± 6.7 years. DZ was co-prescribed in 39 subjects (41.1%) and was associated with a 28.6% reduction of the mean CsA daily dose (P < .001). Patients on DZ had less frequent rejection episodes (P = .002), better renal function (P = .009) and a lower rate of end-stage renal disease (P = .008). Additionally, they developed later cardiac allograft vasculopathy (CAV). We observed no prognostic relevance of DZ co-prescription in univariate and multivariate Cox-regression analyses. In addition to reducing the CsA dose required to maintain adequate blood through levels, DZ may have nephroprotective properties in OHT. The co-administration of DZ may decelerate the development of CAV and reduce the frequency of the rejection episodes. However, the beneficial influence on morbidity has no impact on mortality.

Impact of Toll-like receptor 2 expression in renal allograft rejection

BACKGROUND

An important role of TLR2 has been shown in various experimental models of renal ischaemia/reperfusion injury. To study the expression of TLR2 in renal allograft rejection systematically, we established an experimental rat transplantation model.

METHODS

TLR2 expression was analysed in 99 human renal allograft biopsies, and in rat allografts at Day 6 and 28 after experimental renal transplantation. To discriminate whether regulation of TLR2 was following immunological processes after allogeneic transplantation or was a consequence from ischaemia/reperfusion injury, control animals subjected to syngeneic transplantation or to ischaemia/reperfusion damage were also investigated.

RESULTS

TLR2 mRNA was significantly elevated in rat allografts with acute rejection on Day 6 and decreased spontaneously towards Day 28. TLR2 induction correlated with renal function and TLR2 excretion in the urine of transplanted rats. TLR2 staining was also significantly increased in human allografts with acute rejection. TLR2 protein could be localized in tubular epithelial cells and vascular endothelial cells, and in CD68- and CD4-positive infiltrating cells.

CONCLUSIONS

TLR2 is markedly up-regulated in both experimental and human acute renal allograft rejection. Our data suggest a role for TLR2 during allogen-dependent graft damage after renal transplantation.