Transplant Trial Watch

Comparison of the Effects of Standard Versus Low-dose Prolonged-release Tacrolimus with or without ACEi/ARB on the Histology and Function of Renal Allografts.

Cockfield, S. M., Wilson, S. et al.

Am J Transplant;[record in progress].


Aims
To assess the effects of IF/TA prevalence using a reduced tacrolimus dosing strategy and RAS-blocking AHTs.

Interventions
At randomization, patients were assigned to one of four possible treatments; standard-dose, prolonged-release tacrolimus, plus, either an ACE inhibitor or angiotensin II receptor blocker (n=71), or other antihypretensive therapy (n=69), or low- dose prolonged-release tacrolimus, plus, either an ACE inhibitor or angiotensin II receptor blocker (n=71), or other antihypretensive therapy (n=68), corresponding to two tacrolimus interventions (low vs standard) and two AHT interventions (ACEi/ARB vs OAHT).

Participants
281 adult renal transplant recepients. Of these, 235 completed the study.

Outcomes
This study had two co-primary outcomes: the prevalence of IF/TA at Month 6 and at Month 24. Secondary endpoints included the progression of IF/TA post-transplant, and assessment of renal function, blood pressure and use of antihypertensive agents throughout the study period.

Follow-up
Up to 24 months

CET Conclusions
This interesting multicenter open-label study investigated the interaction between low- and high-dose tacrolimus and use of ACE inhibitors on the development of IF/TA following renal transplantation. The investigators used a 2x2 randomised design to compare low- versus high-dose prolonged release tacrolimus and ACEi/ARB versus other antihypertensive use. Protocol biopsies were taken at baseline, 6 months and 24 months. The largest reduction in 24-month IF/TA came from the use of low-dose tacrolimus, although there was some interaction between the two treatments with the lowest rate of IF/TA seen in the ACEi and low-dose Tac group. Use of ACEi/ARB in conjunction with low-dose tacrolimus also appears to reduce the rejection risk associated with low-dose tac use. Interestingly, post-hoc analysis also demonstrated a significant reduction in the risk of IF/TA with inflammatory infiltrate associated with ACEi/ARB use. Taken together, these results suggest that addition of ACEi/ARB to low-dose tacrolimus early after transplantation is safe and may confer some benefit in the progression of IF/TA and risk of T-cell mediated rejection. It is not clear whether the histopathologists involved in this study were blinded to treatment assignment, raising the risk of measurement bias. Longer-term follow-up will determine whether the early benefits seen translate to differences in graft function and survival.

Jadad score
3

Data analysis
Modified intention-to-treat analysis

Allocation concealment
Yes

Trial registration
ClinicalTrials.gov - NCT00933231

Funding source
Not reported