Kidney Function in Lung Transplant Patients Receiving IV Tacrolimus

Abstract

Purpose Acute kidney injury (AKI) is common after lung transplant (LT), but development of chronic kidney disease (CKD) after AKI has not been well described in the LT population. Historically, UCSD LT team utilized intravenous tacrolimus (IVFK) in place of induction therapy. This study was conducted to determine the rate of AKI and CKD post LT and recovery of AKI while using IVFK. Methods We conducted a single center, retrospective analysis of LT recipients (LTR). KDIGO definitions were used for AKI and CKD. Recovery was SCr value within 25% of baseline. Descriptive statistics and a two-sided t test were used. A multivariate regression evaluated impact of age at transplant (txp), txp type, gender, Scr, duration of IVFK (dur) and supratherapeutic concentrations of IVFK (supraFK) on AKI. Patients (pts) received IVFK with a goal concentration of 20-25 ng/ mL then transitioned to oral when tolerated. SupraFK was defined as >25 ng/ mL and >15 ng/ mL on IV and oral, respectively. Results We studied 82 sequential LTR between 2011 - 2016 who all received IVFK. 76% developed AKI and 70% of pts were stage 2 or higher. The mean baseline SCr of 0.77 mg/ dL increased to 1.99 mg/ dL in the first 14 days post LT. No difference was found in AKI and no AKI groups with respect to the dur of supra FK (p = 0.13) but pts with AKI were on IVFK longer (6 vs 3.5 days, p=0.003). Pts with CKD at 1 year were also on IVFK longer than pts who did not develop CKD (5.9 vs 3.7 days, p=0.03) and this effect remained for 3 years post LT. We found no significant association of IVFK dur in a regression model. Underlying lung disease did not contribute to differences in AKI. Conclusion We found frequent and severe AKI post LT, with a significant portion developing CKD when using an IVFK based regimen. We were unable to detect a significant association between IVFK and renal outcomes, likely due to sample size. UCSD has modified our induction to include basiliximab . IVFK is no longer used, FK is given via oral or sublingual route . A future study is planned to assess this change.