A Rare Case of Rituximab Induced Allergic Interstitial Nephritis with a Good Response to Glucocorticoids

Abstract

Rituximab is a chimeric anti-CD20 monoclonal antibody that has been widely used to treat CD 20 positive hematologic malignancies and some autoimmune conditions. Although usually well tolerated, an increasing number of serious complications related to rituximab have been noted with its wide usage. We report a 67-year-old man who developed biopsy-proven Allergic Interstitial Nephritis (AIN) after treatment with rituximab for his Primary Central Nervous System Lymphoma (PCNSL). Rituximab-induced AIN was confirmed by kidney biopsy, and his kidney function improved to his baseline with supportive care and four weeks of steroid treatment. While rare, AIN could be a possible adverse effect of rituximab. To our knowledge, this is the first case report of a biopsy-proven AIN from rituximab. The association of AIN and rituximab in our case necessitates a high index of suspicion to facilitate early detection of AIN and timely discontinuation of the offending medication. Keywords: Rituximab; Drug induced allergic interstitial nephritis.