Biomarkers for renal recovery - a translational approach for outcome assessment of critically ill patients with acute kidney injury - Renal Recovery

Proteomic analyses demonstrated high levels of alpha-1 microglobulin protein (AMBP) in patients with AKI progression. ROC analyses of AMBP for short-term renal recovery revealed an AUC of 0.906 (95% CI, 0.859 to 0.953) at baseline, 0.684 (95% CI, 0.596 to 0.771) at day 1, 0.750 (95% CI, 0.668 to 0.833) at day 2, and 0.799 (95% CI, 0.713 to 0.884) at day 7 after enrolment. Based on the results, we decided to focus on AMBP at baseline and at day 1. We included 500 patients with KDIGO stage 2/3 (417 (83.4%) with KDIGO stage 2 and 83 (16.6%) with KDIGO stage 3) between December 2016 and December 2018. The mean age was 64.6 (±15.1) years and 70.6% (353) patients were male. The AUC of AMBP at the day of enrolment and day 1 after enrolment for short-term renal recovery was 0.801 (95% CI, 0.762 to 0.841; p<0.0001) and 0.693 (95% CI, 0.644 to 0.741), respectively, and for renal recovery at day 90 AUC 0.624 (95% CI, 0.565 to 0.683) and 0.581 (95% CI, 0.519 to 0.0.644), respectively. The predictive performance of AMBP for renal recovery after 1 year resulted in an AUC 0.641 (95% CI, 0.574 to 0.708) for the day of enrolment and 0.624 (95% CI, 0.0.554 to 0.694) at day 1 after enrolment. Regarding the secondary endpoint, 58.8% (295%500) of the patients suffered from transient AKI and had short-term renal recovery, 34.7% (174/350) recovered renal function after 90 days, 16.9% (85/279) after 365 years. 4 (1.1%) patients at day 90 and 3 (0.8%) patients at day 365 were still dialysis dependent. Mortality rates were 25.9% at day 90 and 29.5% at day 365. MAKE was 35.3% (177/347) at day 90 and 39.0% (196/279) at day 365. The pilot cohort revealed a high predictive performance for transient AKI or short term renal recovery and this could be confirmed in the complete ‘RenalRecovery’ cohort. However, in the long-term after 90 and 365 days, predictive performance was poor.