1 Huntsville Regional Medical Campus, University of Alabama Birmingham School of Medicine, Birmingham, Alabama (R.M.C.).
2 Division of Nephrology, University of California, San Francisco School of Medicine, San Francisco, California, and Division of Research, Kaiser Permanente Northern California, Oakland, California (C.H.).
3 Division of Nephrology, University of California, San Francisco School of Medicine, San Francisco, California (A.N.M.).