Repeat kidney biopsy for lupus nephritis: an important step forward.

There is scant controlled data to guide the use of repeat kidney biopsies to guide therapy in glomerular disease. De Rosa et al. assessed the value of a repeat biopsy during remission in estimating the risk of subsequent relapse of lupus nephritis. They demonstrated the feasibility of a per-protocol repeat biopsy study with prespecified subsequent therapy. Their results will inform the design of future studies of repeat biopsies in lupus nephritis and other kidney diseases.