For the patients who did not have a kidney biopsy, two had a diagnosis of microscopic polyangiitis based on the clinical and biological data confirming the ANCA positivity with a MPO specificity, one had an ANCA negative vasculitis with a diagnosis based on an association between AKI, pulmonary involvement, and purpura lesions, one had a granulomatosis with polyangiitis with an ANCA positivity specific to PR3, and one a polyarteritis nodosa based on the imaging (Supplementary Table S1). Here, MPO is linked to purpura.