Building CRESCENDO – a global registry of glomerulonephritis with crescents

Abstract Crescents represent a non-specific mechanism in response to severe glomerular injury and show a temporal pattern evolving from cellular and fibrocellular to fibrous. Crescentic glomerulonephritis (GN) is defined as ≥50% cellular crescentic glomeruli on kidney histology and is frequently characterized by rapid deterioration of kidney function and features of nephritis. However, little is known on how different types and proportions of crescents affect prognosis and this may differ across diseases forming the spectrum of crescentic GN. To explore this we have devised CRESCENDO, a multinational, longitudinal, observational registry collecting clinical, laboratory and histopathology data from patients with GN and crescents. The registry aims to enroll patients from all continents to explore the prognostic value of crescents on a continuum, ranging from one crescentic glomerulus to 100% crescents on biopsy. We also aim to explore other potential prognostic and diagnostic predictors of a wide range of outcomes (not limited to mortality and kidney survival, but also infections, malignancy, and kidney function recovery), leverage exploratory machine learning approaches of scanned kidney biopsies and test the efficacy and safety of different therapies across crescentic GN spectrum. The findings of CRESCENDO will hopefully help close gaps in the understanding of crescentic GN and will generate further hypotheses providing the basis for subsequent research.