Clinical differential diagnosis of acute tubulointerstitial nephritis and acute tubular necrosis

Objective: To analyze the clinical and laboratory features of patients with acute tubulointerstitial nephritis (ATIN) and its differential diagnosis with acute tubular necrosis (ATN). Methods: From January 2009 to December 2018, patients with ATIN or ATN confirmed by renal biopsy in the Department of Nephrology, Ruijin Hospital ，Shanghai Jiao Tong Universtiy School of Medicine were included. The clinical manifestations and laboratory examination data were collected and analyzed comparatively. Results: During the period, there were 5 537 patients receiving renal biopsy,inclu-ding 135 ATIN cases [2.4% (135/5 537)] and 109 ATN [2.0%(109/5 537)].ATIN accounted for 21.4% (135/630) of the acute kidney disease (AKD) patients. The median age of ATIN patients was 53 years old and the female proportion was 57.0%. Main clinical manifestations of ATIN included fever, rash and arthralgia. Infection, and medicine use and toxic exposure were common inducements of ATIN. Compared with the ATN group, ATIN patients had higher female proportion (57.0% vs 33.9%) and lower BMI (22.9±3.6 vs 24.6±3.9, P