Pitfalls in evaluating the impact of persistent hematuria after induction therapy on kidney prognosis in anti-neutrophil cytoplasmic autoantibody–associated vasculitis

We have a keen interest in the recent article by Benichou et al., which highlights that proteinuria and hematuria following remission induction are associated with outcomes in anti-neutrophil cytoplasmic antibody–associated vasculitis. 1 Benichou N. Charles P. Terrier B. et al. Proteinuria and hematuria after remission induction are associated with outcome in ANCA-associated vasculitis. Kidney Int. 2023; 103: 1144-1155 Abstract Full Text Full Text PDF Scopus (0) Google Scholar This tackles an important topic, given its challenges for physicians. Notably, the authors assert that persistent hematuria following induction therapy correlates with renal relapse but has no significant impact on renal prognosis. However, careful consideration is needed when interpreting these findings for 2 reasons. Proteinuria and hematuria after remission induction are associated with outcome in ANCA-associated vasculitisKidney InternationalVol. 103Issue 6PreviewIn anti-neutrophil cytoplasmic antibody (ANCA)–associated vasculitis (AAV), hematuria and proteinuria are biomarkers reflecting kidney involvement at diagnosis. Yet, the prognostic value of their persistence after immunosuppressive induction therapy, reflecting kidney damage or persistent disease, remains uncertain. To study this, our post hoc analysis included participants of five European randomized clinical trials on AAV (MAINRITSAN, MAINRITSAN2, RITUXVAS, MYCYC, IMPROVE). Urine protein-creatinine ratio (UPCR) and hematuria of spot urine samples collected at the end of induction therapy (four-six months after treatment initiation) were correlated with the occurrence of a combined end point of death and/or kidney failure, or relapses during follow-up. Full-Text PDF The authors replyKidney InternationalVol. 105Issue 2PreviewWe read with interest the comments raised by Taniguchi et al.1 about our study.2 Full-Text PDF