1 Division of Pathology, Department of Medicine, National Jewish Health, Denver, Colo.
2 Immunology Department, PathWest Laboratory Medicine, Perth, Western Australia.
3 Advanced Diagnostic Laboratories, National Jewish Health, Denver, Colo.
4 Division of Pathology, Department of Medicine, National Jewish Health, Denver, Colo; Advanced Diagnostic Laboratories, National Jewish Health, Denver, Colo. Electronic address: knightv@njhealth.org.