[1] Univ Calif Los Angeles, David Geffen Sch Med, Dept Med, Los Angeles, CA 90024 USA
[2] Univ Calif Los Angeles, David Geffen Sch Med, Dept Med Vatche & Tamar Manoukian, Div Digest Dis, 200 Med Plaza Driveway, Los Angeles, CA 90024 USA
[3] Univ Calif Los Angeles, David Geffen Sch Med, Dept Pathol & Lab Med, Los Angeles, CA 90024 USA