Journal of Heprrtology zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA 2000, 33 781-784 Prrnted m Denmark All rrghts reserved Munksgaard Copenhagen Copyright 6 European Assocratron for the Study of the Lwer 2000 zyxwvuts Journal of Hepatology ISSN 0168-8278 Pre-core mutant infections in the Canadian Inuit Gerald Y Mmuk’, Pamela S 0rr1T2, Rosemay Brown 3, Sharon Macdonald2, Rabmda K Chaudhary“ and Paula Temple 1 ‘Liver Dueases Unit, =Northern MedIcal Unit, lKeewatm Regional Health Board, ’ 2Unlverslty of Manztoba, W znmpeg Mamtoba and 4Laboratory Centre for Disease Control, Ottawa, Ontano, Canada Background/Aims: Previous cross-sectional data sug- gested that chronic hepatitis B viral (HBV) infections in the Canadian Inuit were inactive. The aim of this study was to confirm these findings and document the prevalence of the subsequently described “pre-core mutant” variant of HBV in this population. Methods: We obtained sera from residents of five re- mote Canadian Inuit communities. Residents were se- lected if they were known to be hepatitis B surface antigen (HBsAg) positive or had a history of liver dis- ease. HBV serology, HBV-DNA, and pre-core mutant testing were performed by commercially available as- says, polymerase chain reaction (PCR) and direct se- quencing of the viral genome, respectively. Results: Sera were obtained from 176/266 (66%) of selected individuals. Thirty-eight (22%) were HBsAg VIOUSseroepldemlologlc surveys of hepatitis B p” vu-al (HBV) mfectlons m the Canadian Inmt (Es- kimo) have revealed that HBV exposure and carrier rates are approximately 5 and 20 times, respectively, more common m this group than m Caucasians llvmg m southern Canada (l-3) Of particular interest was the finding that the majority of Inmt carriers were more than 20 years old and few had blochemlcal or serologic evidence of active disease (normal ammo- transferases and negative hepatitis B early antigen [HBeAg]) Whether these cross-sectional findings were transient or represented a more permanent feature of this population remained to be determined Smce the pubhcatlon of these reports, a variant of HBV has been described m which a point mutation m the precore region (guamne to ademne at nucleotlde Recezved28 December 1999, revued 2 March accepted 5 Aprrl2000 Correspondence G Y Mmuk, Liver Diseases Unit, GF407, Health Sciences Centre, 820 Sherbrook Street, Wmmpeg, Manitoba, R3A lR9, Canada Tel 204 787 4662 Fax 204 775 4255 positive and 16 (9.1%) anti-HBs positive. Of HBsAg positive carriers 25/38 (66%) were male as compared to 68/138 (49%) of the remaining individuals (~K0.05). Of 37 HBsAg positive carriers, none were HBeAg positive, 36 (97%) anti-HBe positive and one (3%) HBeAg and anti-HBe negative. Liver enzyme and function tests were normal in all cases. 30137 (81%) HBsAg positive carriers were HBV-DNA posi- tive and 26/30 (87%) were pre-core mutant positive. Conclusion: The majority of HBV infections in com- munity-based Canadian Inuit are inactive and the prevalence of pre-core mutant infections is the highest reported to date. Key words: Aboriginal; Hepatitis; Hepatitis B; Inuit; Liver disease; Precore mutant. posltlon 1896) results m defective production of HBeAg despite active vu-al rephcatlon (4) This precore mutant was orlgmally described m a mmorlty of HBV carriers m Mediterranean and Far Eastern countries, but 1s now known to be present m carrier populations throughout the world (5-7) Although orlgmally thought to be more virulent than wild-type HBV, re- cent data suggest that precore mutant mfectlons are also associated with inactive disease (8-10) The purpose of the present study was to determme whether the blochemlcal and serologic profile of HBV carriers m the Canadian Inmt population continues to reflect inactive disease and to document the prevalence of pre-core mutant mfectlons m this population Materials and Methods Study population The govermng bodies of the followmg comrnumtles m the Keewatm Dlstrlct of the Northwest Terrltorles (Fig 1) provided thex approval for partxlpation, Ranlcm Inlet (1991 consensus population 1706), Baker Lake (1186), Coral Harbour (578), Repulse Bay (488) and Chesterfield Inlet (316) Total estimated population 4274 Individuals were selected for serologic testing based on a review of 781