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
Case characteristics

A middle age woman who presented with acute kidney injury (AKI) and features of thrombotic microangiopathy (TMA).

Clinical diagnosis

TMA, most likely atypical hemolytic uremic syndrome.

Differential diagnosis

Causes of TMA with AKI: hemolytic uremic syndrome, thrombotic thrombocytopenic purpura (primary and secondary causes).

Laboratory diagnosis

Thrombocytopenia, elevated lactate dehydrogenase, schistocytes on peripheral blood film, acute kidney injury with normal coagulation profile and complement factor I mutation on genetic testing.

Imaging diagnosis

Computer tomography to exclude underlying malignancy as secondary causes.

Pathological diagnosis

Renal biopsy showing features of TMA with renal cortical necrosis, and acute tubular necrosis.


Plasma exchange, dialysis and eculizumab.

Related reports

Previous cases of aHUS showing remission with initiation of eculizumab and maintenance of remission despite its discontinuation.

Term explanation

AKI: Acute kidney injury; aHUS: Atypical hemolytic uremic syndrome; CFH: Complement factor H; CFI: Complement factor I; MCP: Membrane co-factor protein; PLEX: Plasma exchange; TMA: Thrombotic microangiopathy; TTP: Thrombotic thrombocytopenic purpura.

Experiences and lessons

aHUS is a serious diagnosis that requires a high index of suspicion in cases presenting with unexplained AKI associated with microangiopathy. Renal benefit of eculizumab may be seen even with late initiation of the drug.