1. From the Departments of Pathology (Dr Washington) and Medicine (Dr Berlin), Vanderbilt University Medical Center, Nashville, Tennessee; the Department of Pathology, Inova Fairfax Hospital, Falls Church, Virginia (Dr Branton); Allina Laboratories, Abbott Northwestern Hospital, Minneapolis, Minnesota (Dr Burgart); the Department of Pathology, St Mary's/Duluth Clinic Health System, Duluth, Minnesota