Research Viewpoints Acute Kidney Disease and Outcomes

Viewpoint On

See EJ, Polkinghorne KR, Toussaint ND, Bailey M, Johnson DW, Bellomo R: Epidemiology and Outcomes of Acute Kidney Diseases: A Comparative Analysis. American Journal of Nephrology DOI 10.1159/000515231

It is now generally recognized that the generic disorder designated as acute kidney disease (AKD) by KDIGO is a manifestation of many individual diseases that do not meet the criteria established for either chronic kidney disease (CKD) or acute kidney injury (AKI). The diagnosis of AKD and CKD are mutually exclusive, but AKI is regarded as a subset of AKD. Both AKD and AKI can evolve over time to CKD. The epidemiology and natural history of subjects with AKD need better characterization.

This deficiency has, in part, been remedied by a large retrospective population-wide cohort study of AKD (with or without AKI) in 62,977 patients admitted to an academic medical center in Melbourne, Australia between 2012 and 2016. All of the included patients had a baseline eGFR of >60 mL/min/1.73 m2 and survived for at least 30 days. Using conventional KDIGO diagnostic criteria (using serum creatinine measurements, 906 patients [1.4%] had AKD with AKI, 485 patients [0.7%] had AKD without AKI, and 3,921 patients [6.2%] had AKI alone; stage 1, 76%; stage 2, 18%; stage 3, 7%). The risk factors for AKD and the occurrence of major adverse kidney events (MAKE) – de novo non-dialysis CKD, kidney failure and death – were examined during follow-up in 36,118 patients.

AKD with or without AKI was associated with a substantially higher risk of MAKE, driven largely by transition to CKD, especially in the first 3 months of observation. This is the first of many large epidemiologic studies that will more precisely define the burden and outcomes for AKD, in a fashion that has so successfully been undertaken for AKI and CKD. Many questions remain regarding how to best harmonize the definitions and prognostic factors involved in AKD, AKI, and CKD. The involvement of KDIGO and the International Society of Nephrology in this process augurs a favorable outcome with global implications [1]. Stay tuned…

References

1. KDIGO. Consensus conference on harmonizing acute and chronic kidney disease definition and classification. August, 2020. ISN Academy Webinar on Harmonizing AKD; March 26, 2021.