1University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania (K.M.K., A.F.D.)
2Clinical Laboratories, University of Pittsburgh Medical Center Presbyterian Hospital, Pittsburgh, Pennsylvania (J.A.R.)
3Clinical Laboratories, University of Pittsburgh Medical Center Presbyterian Hospital, and University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania (A.W.P.)
4Clinical Laboratories, University of Pittsburgh Medical Center Presbyterian Hospital, University of Pittsburgh School of Medicine, McGowan Institute for Regenerative Medicine, University of Pittsburgh, and Clinical Laboratory, Children's Hospital of Pittsburgh of UPMC, Pittsburgh, Pennsylvania (K.T.)
Acknowledgment: The authors thank the Special Chemistry Laboratory staff for their technical support.
Disclosures: Authors have disclosed no conflicts of interest. Forms can be viewed at www.acponline.org/authors/icmje/ConflictOfInterestForms.do?msNum=L19-0661.
