Calcineurin Inhibitor-Based Maintenance Immunosuppression in Lung Transplant Recipients: Optimal Serum Levels for Managing Acute Rejection and Renal Function

Calcineurin inhibitors' impact on cardiovascular and renal function, a descriptive study in lung transplant recipients from the North of Spain

Patients undergoing lung transplantation (LTx) need administration of immunosuppressive therapy following the procedure to prevent graft rejection. However, these drugs are not exempt from potential risks. The development of cardiovascular risk factors and impaired renal function in the post-transplantation period are conditions that may be favoured by the use of calcineurin inhibitor (CNI) drugs which could have repercussions on the quality of life and the post-transplantation evolution. To evaluate the cardiovascular and renal toxicity following the administration of CNI as maintenance immunosuppression in lung transplant recipients (LTRs) we reviewed a total number of 165 patients undergoing LTx between 01/01/2015 and 08/12/2018. They were divided into two groups according to the CNI drug administrated: cyclosporine (CsA-group) with 11 patients or tacrolimus (Tac-group), with 154 patients. We evaluated the de novo occurrence of arterial hypertension (HTN), diabetes mellitus (DM), hyperlipidemia and impaired renal function after initiation of CNI administration. In addition to that, the time until each of these events was assessed. A higher rate for developing HTN (p < 0.001) and impaired renal function (p = 0.047) was observed within the CsA-group. The new onset of hyperlipidemia was similar between both CNI groups and de novo appearance of DM was only documented in those LTRs receiving tacrolimus. In this LTRs retrospective study, it was observed that having ≥ 4 tacrolimus trough levels above the upper limit of the proposed interval for each specific post-LTx period was associated with an increased risk for developing renal impairment. No other statistically significant association was found between supratherapeutic CNIs blood levels and the evaluated toxicities.

Impact of Tacrolimus Trough Variability on Acute Rejection Following Lung Transplantation

BACKGROUND

Acute rejection is a risk factor for the development of chronic lung allograft dysfunction, the leading cause of morbidity and mortality in lung transplant recipients. Calcineurin inhibitors are the cornerstone of immunosuppression regimens after lung transplantation.

METHODS

We retrospectively evaluated the association of tacrolimus level variability with total acute rejection score at 12 months post-transplant. Secondary outcomes included the development of chronic lung allograft dysfunction and antibody-mediated rejection at 24months post-transplant. There were 229 lung transplant recipients included.

RESULTS

The mean (standard deviation) total rejection score of the cohort was 1.6 (1.7). Patients with high tacrolimus variability at 0 to 3, 3 to 6, and 6 to 12 months on average scored 0.18 (mean 1.6 vs 1.5; 95% CI): -0.3 to 0.66, P =.46), 0.14 (mean 1.7 vs 1.5; 95% CI: -0.32 to 0.6, P = .55), and 0.12 (mean 1.6 vs 1.5; 95% CI: -0.34 to 0.58, P = .62) point higher in 12-month total acute rejection scores, respectively; however, these differences were not statistically significant. The incidences of chronic lung allograft dysfunction and antibody-mediated rejection were numerically greater in the high variability group throughout certain periods; however, this was not consistent throughout all study timeframes and statistical significance was not evaluated.

CONCLUSIONS

High tacrolimus variability was not associated with increased 12-month total acute rejection score. Further studies are needed to assess long-term outcomes with tacrolimus level variability.