Author information:
(1)Division of Critical Care Medicine, Children's Hospital of Philadelphia, 
Philadelphia, Pennsylvania, USA.
(2)Division of Infectious Diseases, Children's Hospital of Philadelphia, 
Philadelphia, Pennsylvania, USA.
(3)Perelman School of Medicine, University of Pennsylvania, Philadelphia, 
Pennsylvania, USA.
(4)Division of Rheumatology, Children's Hospital of Philadelphia, Philadelphia, 
Pennsylvania, USA.
(5)Division of Hematology and Oncology, Children's Hospital of Philadelphia, 
Philadelphia, Pennsylvania, USA.