1. 1 Department of Laboratory Medicine & Pathology, University of Washington, Seattle
2. 2 Department of Biostatistics, Surveys, College of American Pathologists, Northfield, Illinois
3. 3 Department of Laboratory Improvement Programs, Surveys, College of American Pathologists, Northfield, Illinois
4. 4 Department of Pathology, Anatomy, and Laboratory Medicine, West Virginia University, Morgantown
5. 5 Immunopathology Laboratory, Robert Tomsich Pathology and Laboratory Medicine Institute, Cleveland Clinic, Cleveland, Ohio
6. 6 Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, Ohio
7. 7 Rheumatology Division, Department of Medicine, University of Washington, Seattle