A predictive mortality score in ANCA-associated renal vasculitis

Several scores have been developed to predict mortality at anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) diagnosis. Their prognostic value in Caucasian patients with kidney involvement (AAV-GN) remains uncertain as none has been developed in this specific population. We aimed to propose a novel and more accurate score specific for them.

This multicentric study included patients diagnosed with AAV-GN since January 2000 in four nephrology centers (recorded in the Maine-Anjou AAV-GN Registry). Existing scores and baseline characteristics were assessed at diagnosis before any therapeutic intervention. A multivariable analysis was performed to build a new predictive score for death. Its prognosis performance (area under receiving operating curve and C-index) and accuracy (Brier score) was compared with existing scores. One hundred and eighty-five patients with AAV-GN from the RENVAS registry were used as a validation cohort.

A total of 228 patients with AAV-GN from the Maine-Anjou registry were included to build the new score. It included the four components most associated with death: age, history of hypertension or cardiac disease, creatinine and hemoglobin levels at diagnosis. Overall, 194 patients had all the data available to determine the performance of the new score and existing scores. The new score performed better than the previous ones in the development and in the validation cohort. Among the scores tested, only Five-Factor Score and Japanese Vasculitis Activity Score had good performance in predicting death in AAV-GN.

This original score, named DANGER (Death in ANCA Glomerulonephritis-Estimating the Risk), may be useful to predict the risk of death in AAV-GN patients. Validation in different populations is needed to clarify its role in assisting clinical decisions.