Follow-Up Renal Assessment of Injury Long-Term After Acute Kidney Injury (FRAIL-AKI)

Abstract

Background and objectives Novel urinary kidney damage biomarkers detect AKI after cardiac surgery using cardiopulmonary bypass (CPB-AKI). Although there is growing focus on whether AKI leads to CKD, no studies have assessed whether novel urinary biomarkers remain elevated long term after CPB-AKI. We assessed whether there was clinical or biomarker evidence of long-term kidney injury in patients with CPB-AKI.Design, setting, participants, & measurements We performed a cross-sectional evaluation for signs of chronic kidney injury using both traditional measures and novel urinary biomarkers in a population of 372 potentially eligible children (119 AKI positive and 253 AKI negative) who underwent surgery using cardiopulmonary bypass for congenital heart disease at Cincinnati Children's Hospital Medical Center between 2004 and 2007. A total of 51 patients (33 AKI positive and 18 AKI negative) agreed to long-term assessment. We also compared the urinary biomarker levels in these 51 patients with those in healthy controls of similar age.Results At long-term follow-up (mean duration6SD, 760.98 years), AKI-positive and AKI-negative patients had similarly normal assessments of kidney function by eGFR, proteinuria, and BP measurement. However, AKI-positive patients had higher urine concentrations of IL-18 (48.5 pg/ml versus 20.3 pg/ml [P=0.01] and 20.5 pg/ml [P,0.001]) and liver-type fatty acid-binding protein (L-FABP) (5.9 ng/ml versus 3.9 ng/ml [P=0.001] and 3.2 ng/ml [P,0.001]) than did AKI-negative patients and healthy controls.Conclusions Novel urinary biomarkers remain elevated 7 years after an episode of CPB-AKI in children. However, there is no conventional evidence of CKD in these children. These biomarkers may be a more sensitive marker of chronic kidney injury after CPB-AKI. Future studies are needed to understand the clinical relevance of persistent elevations in IL-18, kidney injury molecule-1, and L-FABP in assessments for potential long-term kidney consequences of CPB-AKI.

The biomarkers for acute kidney injury: A clear road ahead?

“…This would imply that these biomarkers may be integrated into clinical decision algorithms, and could synergistically improve current ability to initiate RRT early. [16,17] However, published studies have many recognized limitations, which preclude the ability to adapt their findings into clinical practice today. While the currently available data are not sufficient to conclude that biomarkers should be used routinely for clinical decision making for RRT initiation, additional data may in the future significantly modify the clinical variability for initiation of RRT, and potentially translate into improved outcomes and costeffectiveness.…”

Effect of Cardiac Surgery-Associated Acute Kidney Injury on Long-Term Outcomes of Chinese Patients: A Historical Cohort Study

“…Notably, the cumulative incidence of CKD stages 3-5 was relatively low (9.9%) in the AKI group, as compared to other studies [7,16], which may be explained by the relatively younger age and lower rate (4.8%) of aortic surgery, which had a great impact on the progression of kidney function [18]. In addition, the signs of CKD may not be detected by routine methods, such as eGFR, proteinuria, and blood pressure measurements [19]. In contrast, patients in the CSA-AKI group had higher urine concentrations of interleukin-18 and liver-type fatty acid-binding protein than the non-AKI patients [20], which indicated that more sensitive biomarkers are needed for assessment of long-term kidney consequence of CSA-AKI.…”

Urinary excretion of liver-type fatty acid-binding protein reflects the severity of sepsis

“…Urinary L-FABP can predict the onset of AKI after cardiac surgery [13,49,50], pediatric cardiopulmonary bypass [17], stem cell transplantation [12], and endovascular and open-abdominal aortic aneurysm repair [16] as well as in intensive care unit populations [15]. Additionally, L-FABP can also predict the progression to end-stage renal disease (ESRD), the onset of cardiovascular disease (CVD), or death for patients with AKI [14,51], type 2 diabetes [8,52], or chronic kidney a b Fig. 2 Expression of the l-fabp gene following hypoxic stress.…”