1. Department of Medicine University of Washington Seattle WA USA
2. Department of Psychosocial & Community Health University of Washington Seattle WA USA
3. Department of Neurology, Multiple Sclerosis Center Swedish Neuroscience Institute Seattle WA USA
4. Department of Pathology University of Utah Salt Lake City UT USA
5. Department of Pathology University of Washington Seattle WA USA
6. Department of Neurology University of Washington Seattle WA USA
7. Group Health Research Institute Seattle WA USA