Background

The effect of acute kidney injury (AKI) after lung transplantation has been described infrequently and with inconsistent results. Using a newly adopted and validated definition of AKI proposed by the Acute Kidney Injury Network (AKIN), we examined the incidence of AKI and associated renal morbidity and short-term and long-term mortality.

Methods

We retrospectively evaluated data of 657 patients who underwent lung transplantation from 1997 to 2009. Outcomes analyzed were the incidence of AKI, as defined and categorized into 3 stages according to creatinine criteria from the AKIN classification (AKIN 1, AKIN 2, and AKIN 3), cumulative incidence of chronic kidney disease (CKD), as defined by an estimated glomerular filtration rate ≤ 29 ml/min/1.73 m(2), and/or the onset of end-stage renal disease, as defined by the need for renal replacement therapy for 8 weeks with no recovery on follow-up or need for kidney transplant, and long-term mortality.

Results

We identified 424 patients (65%) who had at least 1 AKI (309 [47%] AKIN 1 and 115 [17%] AKIN 2-3) event in the first 2 weeks after transplantation. At 1 year, the cumulative incidence of CKD was 5.8%, 12.8%, 24.5 % in the no-AKI, AKIN 1, and AKIN 2-3 patients, respectively. After a median follow-up of 2.2 years, 277 (42%) died. One-year patient survival was 91%, 82%, 66% in the no-AKI, AKIN 1, and AKIN 2-3 patients, respectively. Adjusting for age, sex, race, type and cause of lung transplant, diabetes, and hypertension, the hazard ratio for death was 1.7 (95% confidence interval, 1.2-2.2; p = 0.0002) for AKIN 1 and 2.9 (95% confidence interval, 1.7-3.7; p < 0.001) for AKIN 2-3.

Conclusions

AKI is a common complication after lung transplantation and is associated with increased risk of CKD and all cause-mortality on long-term follow-up.