Disease modification in immunoglobulin A nephropathy

With the rapidly expanding therapeutic landscape in IgA nephropathy, that incorporates new drugs with varied mechanisms of action, many of which may lead to modification of the fundamental pathophysiology of the world's commonest glomerular disease, thoughts are now turning to how we should define disease modification in IgA nephropathy. In the absence of validated biomarkers that reflect the pathogenic cascade we currently have to rely on proteinuria and eGFR, some would also advocate for inclusion of haematuria, and others for galactose-deficient IgA. In this review the approach to defining disease modification in IgA nephropathy is discussed, the approaches for how we could measure this modification and why a definition will be important as more and more new treatments become available for nephrologists.