Case Report
Copyright ©The Author(s) 2017. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Nephrol. Nov 6, 2017; 6(6): 243-250
Published online Nov 6, 2017. doi: 10.5527/wjn.v6.i6.243
Atypical hemolytic-uremic syndrome due to complement factor I mutation
Abdullah H Almalki, Laila F Sadagah, Mohammed Qureshi, Hatim Maghrabi, Abdulrahman Algain, Ahmed Alsaeed
Abdullah H Almalki, Laila F Sadagah, Mohammed Qureshi, Hatim Maghrabi, Abdulrahman Algain, Ahmed Alsaeed, Ministry of National Guard, Jeddah 21423, Saudi Arabia
Abdullah H Almalki, Hatim Maghrabi, Ahmed Alsaeed, King Saud Bin Abdulaziz University for Health Sciences, Ministry of National Guard, Jeddah 21423, Saudi Arabia
Author contributions: Almalki AH carried out literature search, wrote the abstract and discussion, and revised and aligned the whole manuscript; Sadagah LF conducted independent literature search and wrote the background; Algain A collected clinical information and wrote the initial case description; Qureshi M revised all collected clinical information and wrote the final case description and the draft of the abstract; Maghrabi H prepared the slides, provided histological description, and aided in writing the case description; Alsaeed A carried out independent search on hematologic literature and revised and edited the discussion; all authors read and approved the final manuscript.
Institutional review board statement: This case report was exempt from the Institutional Review Board standards at King Abdulaziz International Medical Research Centre.
Informed consent statement: The patient involved in this study gave written informed consent authorizing the use and disclosure of her clinical data.
Conflict-of-interest statement: All authors have no conflict of interest to declare.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Correspondence to: Abdullah H Almalki, Section Head, Department of Medicine, King Abdulaziz Medical City, Western Region, PO Box 9515, Jeddah 21423, Saudi Arabia.
Telephone: +966-12-2266666 Fax: +966-2-2266200
Received: June 27, 2017
Peer-review started: June 28, 2017
First decision: September 4, 2017
Revised: September 12, 2017
Accepted: November 1, 2017
Article in press: November 1, 2017
Published online: November 6, 2017

Atypical hemolytic-uremic syndrome (aHUS) is a rare disease of complement dysregulation leading to thrombotic microangiopathy (TMA). Renal involvement and progression to end-stage renal disease are common in untreated patients. We report a 52-year-old female patient who presented with severe acute kidney injury, microangiopathic hemolytic anemia, and thrombocytopenia. She was managed with steroid, plasma exchange, and dialysis. Kidney biopsy shows TMA and renal cortical necrosis. Genetic analysis reveals heterozygous complement factor I (CFI) mutation. Eculizumab was initiated after 3 mo of presentation, continued for 9 mo, and stopped because of sustained hematologic remission, steady renal function, and cost issues. Despite this, the patient continued to be in hematologic remission and showed signs of renal recovery, and peritoneal dialysis was stopped 32 mo after initiation. We report a case of aHUS due to CFI mutation, which, to the best of our knowledge, has not been reported before in Saudi Arabia. Our case illustrates the challenges related to the diagnosis and management of this condition, in which a high index of suspicion and prompt treatment are usually necessary.

Keywords: Thrombotic microangiopathy, Atypical hemolytic-uremic syndrome, Complement factor I mutation

Core tip: Atypical hemolytic-uremic syndrome (aHUS) is a rare disorder. In some cases, complement mutation can be identified. The most common cases involved mutations of genes for complement factor H and membrane co-factor protein, whereas rare cases were linked to complement factor I (CFI) mutation. We here describe the first case of aHUS due to CFI mutation in Saudi Arabia. Our case presented with interesting characteristics including late recovery of kidney failure from dialysis upon initiation of eculizumab and persistent hematologic and renal remissions despite discontinuation of eculizumab.