Faculty and Staff

Program Directors and Administrative Staff


Peter Grayson, M.D., M.Sc.
Acting Director, Rheumatology Fellowship Program Director, NIAMS
Chief, Vasculitis Translational Research Program, NIAMS
Clinical and Research Faculty
peter.grayson@nih.gov

Robert Colbert, M.D., Ph.D.
Clinical Director, NIAMS 
Chief, Pediatric Translational Research Branch, NIAMS 
Clinical and Research Faculty 
Site Director, Pediatric Program 
robert.colbert@nih.gov

Ronnie Gladney
Rheumatology Fellowship Program Coordinator
ronnie.gladney@nih.gov


NIAMS Scholars


Brian Dizon, M.D., Ph.D.
Brian Dizon received his B.S. in Microbiology/Immunology and B.A. in Chemistry at the University of Miami in 2003. With a strong interest in immunology, he continued his M.D. and Ph.D. training at the University of Alabama at Birmingham. Under the mentorship of Dr. John Kearney, he explored the functions of autoreactive carbohydrate-specific B cells in a mouse model of autoimmune diabetes. With his continued interest in regulating autoreactive B cells in human autoimmune diseases, Dr. Dizon completed an internal medicine pediatrics residency at the University of Rochester, followed by a combined adult and pediatric rheumatology fellowship at Children’s National Hospital and the NIAMS. In 2019, he joined Dr. Pierce’s lab as a fellow to study the signaling and regulatory mechanisms in autoreactive B cells, which may impact systemic autoimmune diseases such as lupus. In 2021, Dr. Dizon completed his rheumatology training and continued in Dr. Pierce’s lab as a NIAMS Metzger Scholar to further his research and clinical training. In the lab, he examines the signaling mechanisms of autoreactive B cells, such as atypical B cells, to understand their functions and regulation in chronic inflammation (such as malaria and systemic autoimmune disease), as well as vaccinations that elicit long-lasting humoral immunity.

Sandra Williams, M.D., Ph.D.
Sandra Williams received her undergraduate degree from the University of Chicago and her M.D. and Ph.D. from Washington University in St. Louis. She completed her residency in internal medicine at Yale New Haven Hospital and her rheumatology fellowship at the NIH. Dr. Williams was subsequently promoted to Metzger Scholar in Translational Research at the NIAMS. Her research studies the intersection of RNA quality control and autoimmune diseases such as systemic lupus erythematosus (SLE).


Program Faculty


Tim Bhattacharyya, M.D.
Head, Clinical and Investigative Orthopedics Surgery Unit, NIAMS 
Clinical Faculty
timothy.bhattacharyya@nih.gov

Robert Colbert, M.D., Ph.D.
Clinical Director, NIAMS 
Chief, Pediatric Translational Research Branch, NIAMS 
Senior Investigator
robert.colbert@nih.gov

Marcela Ferrada, M.D.
Staff Clinician, NIAMS
ferradama@mail.nih.gov

Alice Fike, MS, NP
Nurse Practitioner, NIAMS
alice.fike@nih.gov

Peter Grayson, M.D., M.Sc.
Acting Director, Rheumatology Fellowship Program Director, NIAMS
Chief, Vasculitis Translational Research Program, NIAMS
Investigator
peter.grayson@nih.gov

Sarthak Gupta, M.D.
Staff Clinician, NIAMS
Assistant Research Physician
sarthak.gupta@nih.gov

Safaraz Hasni, M.D.
Staff Clinician, NIAMS
Associate Research Physician
safaraz.hasni@nih.gov

Mariana Kaplan, M.D.
Chief, Systemic Autoimmunity Branch, NIAMS 
Senior Investigator
mariana.kaplan@nih.gov

Daniel Kastner, M.D., Ph.D.
Distinguished Investigator, NHGRI
Adjunct Investigator, NIAMS
dan.kastner@nih.gov

Hanna Kim, M.S., M.D.
Assistant Clinical Investigator
hanna.kim@nih.gov

Laura Lewandowski, M.S., M.D.
Assistant Clinical Investigator
laura.lewandowski@nih.gov

Amanda Ombrello, M.D.
Staff Clinician, NHGRI 
amanda.ombrello@nih.gov

Michael Ombrello, M.D.
Head, Translational Genetics and Genomics Unit, NIAMS
Investigator
ombrellomj@nih.gov

John O’Shea, M.D.
Scientific Director, NIAMS
Chief, Molecular Immunology and Inflammation Branch, NIAMS
Senior Investigator
john.oshea@nih.gov

Iago Pinal-Fernandez, M.D., Ph.D.
Staff Clinician, NIAMS
iago.pinalfernandez@nih.gov

Kaitlin Quinn, M.D.
Staff Clinician, NIAMS
kaitlin.quinn@nih.gov

Yani Ruiz-Perdomo, MSN, CRNP
Adjunct faculty, NIAMS
Yanira.ruiz-perdomo@nih.gov

Adam Schiffenbauer, M.D.
Staff Clinician, NIEHS
Associate Research Physician
adam.schiffenbauer@nih.gov


Away Rotations

Philip Seo
Hopkins Program Director

Daniel Bunker
Georgetown Program Director

Last Updated: August 2022