Defining improvement in chronic kidney disease: regression and remission

International definitions exist for chronic kidney disease (CKD) progression and kidney failure but despite evidence that kidney function may improve, there are no agreed definitions for regression and remission of CKD. In the light of recent novel kidney protective therapies and the promise of regenerative medicine to reverse kidney damage, it is time to critically examine these neglected aspects of CKD epidemiology.

We propose that CKD regression is viewed as a process of improvement defined as a sustained increase in glomerular filtration rate (GFR) by ≥25% and an improvement in GFR category or increase in GFR of 1≥ml/min/year, whereas remission is considered a category of improvement defined as GFR ≥60 ml/min/1.73m 2 and urine albumin to creatinine ratio <30 mg/g. Several recent studies have reported improvement in kidney function in populations with CKD, even in the absence of specific therapy. Regression and remission of CKD are associated with increased likelihood of sustained improvement in kidney function as well as improved survival.

Further research is warranted to validate the proposed definitions and investigate associated mechanisms. We look to a future in which the goal of therapy is not merely to slow CKD progression but to improve kidney function and seek a cure.