1. From Pediatric Rheumatology, Hospital for Special Surgery and Weill Medical College of Cornell University, New York, NY (M.E.R., L.M.A.A., L.I., T.J.A.L.) and Divisions of Pediatric Infectious Diseases and Immunology (D.J.S., M.H.W., W.Z., K.S.M., M.A.) and Cardiology (T.M.D.), Cedars-Sinai Medical Center, and Department of Pathology and Laboratory Medicine, David Geffen School of Medicine at the University of California (M.C.F.), Los Angeles, Calif.