Tehran University of Medical Sciences Case Reports in Clinical Practice 2538-2683 3 4 2019 04 17 106 112 Amirhesam Alirezaei Clinical Research and Development Center, Shahid Modarres Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran, Department of Nephrology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Mahmood Bakhtiyari Department of Community Medicine, Faculty of Medicine, Alborz University of Medical Sciences, Karaj, Iran. Elham Zare Department of Internal Medicine, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran. 2018 08 25 2018 11 18 We report a 25-year-old man who was initially presented with Rapidly Progressive Glomerulonephritis (RPGN) in Shahid Modarress Hospital, Tehran, Iran. His diagnosis was Anti-Glomerular Basement Membrane (Anti-GBM) disease that was confirmed by kidney biopsy, as his serum Anti-GBM antibody was undetectable. Although the patient was on cyclophosphamide and high dose prednisolone, he developed Thrombotic Thrombocytopenic Purpura (TTP). We initiated treatment with a high dose of prednisone and plasmapheresis. Because of his poor response, rituximab was administered. After that, the patient’s hematologic criteria and clinical symptoms improved to an acceptable level. Our case is a unique form of negative serum Anti-GBM antibody disease which was complicated with TTP and responded to treatment with rituximab https://crcp.tums.ac.ir/index.php/crcp/article/view/213 https://crcp.tums.ac.ir/index.php/crcp/article/download/213/301