AUTOIMMUNE LIVER DISEASE IN ALASKA NATIVE PEOPLE: PREVALENCE UPDATE

Monday, 18 August 2014
Exhibit hall (Dena'ina Center)
Tammy Choromanski, BS , ANTHC, Anchorage, AK
Brian McMahon, MD , ANTHC, Anchorage, AK
Stephen Livingston, MD , ANTHC, Anchorage, AK
Elizabeth Ferucci, MD , ANTHC, Anchorage, AK
Julia Plotnik, BS , ANTHC, Anchorage, AK
INTRODUCTION:  Autoimmune liver disease has been previously reported to occur with a high prevalence in the Alaska Native population. The objective to this study was to update the prevalence and examine characteristics of autoimmune liver disease in Alaska Native people. 

METHODS:  Alaska Native people consented to a population-based study of autoimmune hepatitis (AIH) were included in the analysis. The diagnosis of AIH was confirmed as probable or definite AIH according to the International Autoimmune Hepatitis Group (IAHG) criteria. Prevalence was calculated based on the 2012 year Alaska Native user population data for Alaska Area IHS, with 95% confidence intervals. Demographic characteristics and clinical features were described and compared across groups. 

RESULTS:  120 people with definite or probable AIH were identified (84 alive as of January 1, 2012). Based on this number, the prevalence of AIH Alaska Native people was 58.58/100,000 (95% CI = 47.32-72.51). The mean age at diagnosis was 50.5 years. The female to male ratio overall was 13:1. Of the 120 patients, 61 presented with acute hepatitis (ALT > 400 10XULN). The demographic characteristics (age, gender) were similar in those presenting with acute vs. non-acute hepatitis (p>0.05). There were a total of 38 deaths. Of those deaths 24 (63.2%) were not liver related deaths and 11 (28.9%) were liver related. The mean age at death was 63.1 (and does not differ by liver related vs. non-liver-related cause of death).

CONCLUSIONS:  This study demonstrates that the prevalence of AIH is higher than previous reports in the Alaska Native population and much higher than reported prevalence in other populations.  Since only consented people were included in this analysis, the true prevalence of AIH is likely even higher.