title: Cohort profile: golestan hepatitis B cohort study- a prospective long term study in northern iran ​.
abstract: Hepatitis B virus (HBV) infection is the most common cause of end stage liver disease in Iran and in Golestan province. Large-scale population-based prospective cohort studies with long term follow-up are the method of choice to accurately understand the natural course of HBV infection. To date, several studies of HBV epidemiology, natural history, progression to cirrhosis and association with HCC have been reported from other countries. However, few of these are prospective and fewer still are population-based. Moreover, the underlying molecular mechanisms and immunogenetic determinants of the outcome of HBV infection especially in low and middle income countries remains largely unknown. Therefore, the hepatitis B cohort study (HBCS), nested as part of the Golestan Cohort Study (GCS), Golestan, Iran was established in 2008 with the objective to prospectively investigate the natural course of chronic hepatitis B with reference to its epidemiology, viral/host genetic interactions, clinical features and outcome in the Middle East where genotype D HBV accounts for >90% of infections. In 2008, a baseline measurement of HBV surface antigen (HBsAg) was performed on stored serum samples of all GCS participants. A sub-cohort of 3,505 individuals were found to be HBsAg positive and were enrolled in the Golestan HBCS. In 2011, all first degree relatives of HBsAg positive subjects including their children and spouses were invited for HBV serology screening and those who were positive for HBsAg were also included in the Golestan HBCS.
authors.affiliation: Liver and Pancreatobiliary Diseases Research Center, Digestive Disease Research Institute, Shariati Hospital, Tehran university of Medical Sciences, Tehran, Iran.
authors.forename: Hossein
authors.initials: H
authors.lastname: Poustchi
authors.affiliation: Liver and Pancreatobiliary Diseases Research Center, Digestive Disease Research Institute, Shariati Hospital, Tehran university of Medical Sciences, Tehran, Iran.
authors.forename: Aezam
authors.initials: A
authors.lastname: Katoonizadeh
authors.affiliation: Liver and Pancreatobiliary Diseases Research Center, Digestive Disease Research Institute, Shariati Hospital, Tehran university of Medical Sciences, Tehran, Iran ; Division of Gastroenterology and Hepatology, Department of Medicine, Johns Hopkins Medical Institutions, Baltimore, USA.
authors.forename: Mohammad Reza
authors.initials: MR
authors.lastname: Ostovaneh
authors.affiliation: Liver and Pancreatobiliary Diseases Research Center, Digestive Disease Research Institute, Shariati Hospital, Tehran university of Medical Sciences, Tehran, Iran.
authors.forename: Shirin
authors.initials: S
authors.lastname: Moossavi
authors.affiliation: Liver and Pancreatobiliary Diseases Research Center, Digestive Disease Research Institute, Shariati Hospital, Tehran university of Medical Sciences, Tehran, Iran.
authors.forename: Maryam
authors.initials: M
authors.lastname: Sharafkhah
authors.affiliation: Liver and Pancreatobiliary Diseases Research Center, Digestive Disease Research Institute, Shariati Hospital, Tehran university of Medical Sciences, Tehran, Iran ; Storr Liver Unit, Westmead Millennium, University of Sydney and Westmead Hospital, Westmead, NSW, Australia.
authors.forename: Saeed
authors.initials: S
authors.lastname: Esmaili
authors.affiliation: Liver and Pancreatobiliary Diseases Research Center, Digestive Disease Research Institute, Shariati Hospital, Tehran university of Medical Sciences, Tehran, Iran.
authors.forename: Akram
authors.initials: A
authors.lastname: Pourshams
authors.affiliation: Liver and Pancreatobiliary Diseases Research Center, Digestive Disease Research Institute, Shariati Hospital, Tehran university of Medical Sciences, Tehran, Iran.
authors.forename: Ashraf
authors.initials: A
authors.lastname: Mohamadkhani
authors.affiliation: Liver and Pancreatobiliary Diseases Research Center, Digestive Disease Research Institute, Shariati Hospital, Tehran university of Medical Sciences, Tehran, Iran.
authors.forename: Sima
authors.initials: S
authors.lastname: Besharat
authors.affiliation: Liver and Pancreatobiliary Diseases Research Center, Digestive Disease Research Institute, Shariati Hospital, Tehran university of Medical Sciences, Tehran, Iran.
authors.forename: Shahin
authors.initials: S
authors.lastname: Merat
authors.affiliation: Liver and Pancreatobiliary Diseases Research Center, Digestive Disease Research Institute, Shariati Hospital, Tehran university of Medical Sciences, Tehran, Iran.
authors.forename: Mehdi
authors.initials: M
authors.lastname: Mohamadnejad
authors.affiliation: Storr Liver Unit, Westmead Millennium, University of Sydney and Westmead Hospital, Westmead, NSW, Australia.
authors.forename: Jacob
authors.initials: J
authors.lastname: George
authors.affiliation: Liver and Pancreatobiliary Diseases Research Center, Digestive Disease Research Institute, Shariati Hospital, Tehran university of Medical Sciences, Tehran, Iran.
authors.forename: Reza
authors.initials: R
authors.lastname: Malekzadeh