Retrospective Cohort Study
Copyright ©The Author(s) 2017. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Nov 21, 2017; 23(43): 7716-7726
Published online Nov 21, 2017. doi: 10.3748/wjg.v23.i43.7716
Epidemiology and natural history of Wilson’s disease in the Chinese: A territory-based study in Hong Kong between 2000 and 2016
Ka-Shing Cheung, Wai-Kay Seto, James Fung, Lung-Yi Mak, Ching-Lung Lai, Man-Fung Yuen
Ka-Shing Cheung, Wai-Kay Seto, James Fung, Lung-Yi Mak, Ching-Lung Lai, Man-Fung Yuen, Department of Medicine, The University of Hong Kong, Queen Mary Hospital, Hong Kong 999077, China
Wai-Kay Seto, James Fung, Ching-Lung Lai, Man-Fung Yuen, State Key Laboratory for Liver Research, The University of Hong Kong, Hong Kong 999077, China
Author contributions: Cheung KS designed and performed the study, were involved in statistical analysis and interpretation of the data, and wrote the manuscript; Seto WK and Mak LY performed the study, statistical analysis and interpretation of the data; Fung J, Lai CL and Yuen MF revised and edited the manuscript.
Institutional review board statement: This study was approved by The Institutional Review Board of The University of Hong Kong/Hospital Authority, Hong Kong West Cluster.
Informed consent statement: The Institutional Review Board of The University of Hong Kong/Hospital Authority waived the need for written informed consent as there were no direct contact with eligible subjects and no additional blood taking.
Conflict-of-interest statement: The authors have no conflicts of interest.
Data sharing statement: No additional data are available.
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: Man-Fung Yuen, Professor, Department of Medicine, The University of Hong Kong, Queen Mary Hospital, Pokfulam Road, Hong Kong 999077, China. mfyuen@hkucc.hku.hk
Telephone: +852-22553984 Fax: +852-28162863
Received: July 28, 2017
Peer-review started: July 30, 2017
First decision: August 29, 2017
Revised: September 25, 2017
Accepted: September 28, 2017
Article in press: September 28, 2017
Published online: November 21, 2017
Processing time: 114 Days and 22.7 Hours
ARTICLE HIGHLIGHTS
Research background

There are few studies on the epidemiology and natural history of Wilson’s disease in the Chinese population. The authors conducted a territory-based study in Hong Kong (HK) with a population of 7.3 million to address this issue.

Research motivation

Epidemiology data are important for recognizing the temporal trend of a particular disease, understanding the natural history and risk factors, as well as for resource allocation.

Research objectives

To investigate the epidemiology and natural history of Wilson’s disease in the Chinese population.

Research methods

Data were retrieved from the Clinical Data Analysis and Reporting System (CDARS) and Clinical Management System (CMS) of the Hong Kong Hospital Authority. The study observation period was from 2000 to 2016. Cases of Wilson’s disease between 1999 and 2016 were identified from CDARS by the International Classification of Diseases (ICD)-9 code of 275.1. The incidence rate and prevalence of Wilson’s disease between 2000 and 2016 were calculated. Evaluation of the count data and temporal trends was assessed by Poisson regression model. Cox proportional hazards model was used to identify variables that were associated with adverse outcomes. Kaplan-Meier method was used to analyze the adverse outcomes.

Research results

The authors identified 211 patients (male-to-female ratio 0.97:1; median age 27.2 years, IQR: 17.1-38.6 years; median follow-up 8.0 years, IQR: 5.0-14.0 years). The average annual incidence rate and prevalence were 1.44 per million person-years and 17.93 per million, respectively. Between 2000 and 2016, the annual incidence rate decreased from 1.65 to 1.23 per million person-years (Poisson P = 0.010), while the annual prevalence increased from 7.80 to 25.20 per million (Poisson P < 0.001). Among the 176 patients with hepatic involvement, 38 (21.6%) had cirrhosis, three (1.7%) developed hepatocellular carcinoma, 24 (13.6%) underwent liver transplantations, and 26 (14.8%) died. Seven patients had concomitant chronic viral hepatitis B or C. The 5- and 10-year overall survival rates were 92.6% and 89.5%, and for transplant-free survival rates 91.8% and 87.4%, respectively. Cirrhosis and possibly chronic viral hepatitis were associated with poorer overall survival.

Research conclusions

There was a considerable increase in the prevalence of Wilson’s disease in the Chinese population. The long-term survival was good except in patients with cirrhosis or concomitant viral hepatitis.

Research perspectives

The epidemiology of Wilson’s disease was described in a well defined Chinese population, and factors associated with overall survival and transplant-free survival were identified. Future collaboration with the hepatology units from all public and private hospitals is warranted to allow for an even more precise estimate of the epidemiology of Wilson’s disease and to investigate other potential risk factors for reduced transplant-free survival (e.g., metabolic factors).