Identification of the Causative Drug in Drug-induced Acute Interstitial Nephritis

Inclusion Criteria: * Age ≥18 years * Acute renal failure with an eGFR \< 60 ml/min/1.73m2 by CKD-EPI managed in the participating centers in the study * Histologically proven DAIN by renal biopsy (anatomopathological reading in each center according to local habits): presence of an infiltration of inflammatory cells (lymphocytes, monocytes, plasmocytes, eosinophils) in the interstitium accompanied by a variable degree of interstitial edema and fibrosis * Successful diagnosis of DAIN with identification of one or more attributable drugs * Signed consent * Membership in a social security plan or entitled person Exclusion Criteria: * Anatomic-clinical suspicion of AIN of infectious or autoimmune cause or associated with systemic diseases (Sjögren's syndrome, sarcoidosis, tubulointerstitial nephritis syndrome and uveitis, systemic lupus, IgG4-associated disease) * Kidney transplant patients * Current immunosuppressive treatment at the time of allergological testing (test results not interpretable) * Participation in other interventional research * Patient under state medical assistance * Patient deprived of liberty or under legal protection * Pregnancy