Case Report
Copyright ©The Author(s) 2017. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Sep 21, 2017; 23(35): 6540-6545
Published online Sep 21, 2017. doi: 10.3748/wjg.v23.i35.6540
Acquired amegakaryocytic thrombocytopenia previously diagnosed as idiopathic thrombocytopenic purpura in a patient with hepatitis C virus infection
Shojiro Ichimata, Mikiko Kobayashi, Kohei Honda, Soichiro Shibata, Akihiro Matsumoto, Hiroyuki Kanno
Shojiro Ichimata, Mikiko Kobayashi, Kohei Honda, Hiroyuki Kanno, Department of Pathology, Shinshu University School of Medicine, Matsumoto, Nagano 390-8621, Japan
Soichiro Shibata, Akihiro Matsumoto, Department of Medicine, Shinshu University School of Medicine, Matsumoto, Nagano 390-8621, Japan
Author contributions: Ichimata S and Kobayashi M performed the histological evaluation, analyzed the serum sample, and drafted the manuscript; Honda K analyzed the serum sample; Shibata S and Matsumoto A evaluated clinical data; Kanno H performed the histological evaluation, analyzed the serum sample, and critically reviewed the manuscript.
Institutional review board statement: This case report was exempt from the Institutional Review Board standard at Shinshu University School of Medicine.
Informed consent statement: All study participants, or their legal guardian, provided informed consent prior to study enrollment.
Conflict-of-interest statement: The authors have no conflict of interest.
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: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Mikiko Kobayashi, MD, PhD, Department of Pathology, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto 390-8621, Japan. mikko@shinshu-u.ac.jp
Telephone: +81-263-372607 Fax: +81-263-372609
Received: May 18, 2017
Peer-review started: May 18, 2017
First decision: June 22, 2017
Revised: July 6, 2017
Accepted: August 8, 2017
Article in press: August 8, 2017
Published online: September 21, 2017
Abstract

We report the first case of a patient with hepatitis C virus (HCV) infection and idiopathic thrombocytopenic purpura (ITP), who later developed acquired amegakaryocytic thrombocytopenia (AAMT), with autoantibodies to the thrombopoietin (TPO) receptor (c-Mpl). A 64-year-old woman, with chronic hepatitis C, developed severe thrombocytopenia and was diagnosed with ITP. She died of liver failure. Autopsy revealed cirrhosis and liver carcinoma. In the bone marrow, a marked reduction in the number of megakaryocytes was observed, while other cell lineages were preserved. Therefore, she was diagnosed with AAMT. Additionally, autoantibodies to c-Mpl were detected in her serum. Autoantibodies to c-Mpl are one of the causes of AAMT, acting through inhibition of TPO function, megakaryocytic maturation, and platelet formation. HCV infection induces several autoantibodies. HCV infection might also induce autoantibodies to c-Mpl, resulting in the development of AAMT. This mechanism may be one of the causes of thrombocytopenia in patients with HCV infection.

Keywords: Hepatitis C virus, Acquired amegakaryocytic thrombocytopenia, Anti-thrombopoietin receptor (c-Mpl) autoantibodies, Idiopathic thrombocytopenic purpura, Thrombocytopenia

Core tip: Thrombocytopenia occurs frequently in patients with hepatitis C virus (HCV) infection. Acquired amegakaryocytic thrombocytopenia (AAMT) is one of the causes of severe thrombocytopenia. The exact mechanisms of AAMT have not been fully elucidated. However, patients with autoantibodies to thrombopoietin receptor (c-Mpl) develop AAMT. Similarly, autoantibodies are sometimes generated in patients with HCV infection. Here, we report the first case of a patient with HCV infection who later developed AAMT with autoantibodies to c-Mpl. AAMT with autoantibodies to c-Mpl may be one of the causes of thrombocytopenia in patients with HCV infection.