Incidence and Impact of Acute Kidney Injury after Liver Transplantation: A Meta-Analysis

Abstract

Background: The study's aim was to summarize the incidence and impacts of post-liver transplant (LTx) acute kidney injury (AKI) on outcomes after LTx.

Methods: A literature search was performed using the MEDLINE, EMBASE and Cochrane Databases from inception until December 2018 to identify studies assessing the incidence of AKI (using a standard AKI definition) in adult patients undergoing LTx. Effect estimates from the individual studies were derived and consolidated utilizing random-effect, the generic inverse variance approach of DerSimonian and Laird. The protocol for this systematic review is registered with PROSPERO (no. CRD42018100664).

Results: Thirty-eight cohort studies, with a total of 13,422 LTx patients, were enrolled. Overall, the pooled estimated incidence rates of post-LTx AKI and severe AKI requiring renal replacement therapy (RRT) were 40.7% (95% CI: 35.4%⁻46.2%) and 7.7% (95% CI: 5.1%⁻11.4%), respectively. Meta-regression showed that the year of study did not significantly affect the incidence of post-LTx AKI (p = 0.81). The pooled estimated in-hospital or 30-day mortality, and 1-year mortality rates of patients with post-LTx AKI were 16.5% (95% CI: 10.8%⁻24.3%) and 31.1% (95% CI: 22.4%⁻41.5%), respectively. Post-LTx AKI and severe AKI requiring RRT were associated with significantly higher mortality with pooled ORs of 2.96 (95% CI: 2.32⁻3.77) and 8.15 (95%CI: 4.52⁻14.69), respectively. Compared to those without post-LTx AKI, recipients with post-LTx AKI had significantly increased risk of liver graft failure and chronic kidney disease with pooled ORs of 3.76 (95% CI: 1.56⁻9.03) and 2.35 (95% CI: 1.53⁻3.61), respectively.

Conclusion: The overall estimated incidence rates of post-LTx AKI and severe AKI requiring RRT are 40.8% and 7.0%, respectively. There are significant associations of post-LTx AKI with increased mortality and graft failure after transplantation. Furthermore, the incidence of post-LTx AKI has remained stable over the ten years of the study.

Keywords: Acute kidney injury; Acute renal failure; Epidemiology; Incidence; Liver Transplantation; Meta-analysis; Systematic reviews; Transplantation.

Figure 1

Outline of our search methodology.

Figure 2

Forest plots of the included studies assessing incidence rates of post-LTx AKI. A diamond data marker represents the overall rate from each included study (square data marker) and 95% confidence interval.

Figure 3

Forest plots of the included studies assessing incidence rates of severe AKI requiring RRT following LTx. A diamond data marker represents the overall rate from each included study (square data marker) and 95% confidence interval.

Figure 4

Meta-regression analyses showed no significant impact of year of study on the incidence of post-LTx AKI (p = 0.81). The solid black line represents the weighted regression line based on variance-weighted least squares. The inner and outer lines show the 95% confidence interval and prediction interval around the regression line. The circles indicate log event rates in each study.

Figure 5

Forest plots of the included studies assessing liver graft failure among patients with post-LTx AKI. A diamond data marker represents the overall rate from each included study (square data marker) and 95% confidence interval.

Figure 6

Forest plots of the included studies assessing CKD risk among patients with post-LTx AKI. A diamond data marker represents the overall rate from each included study (square data marker) and 95% confidence interval.