Dr. Steven Butler is a graduate of University of Chicago. He received his medical degree from Pritzker School of Medicine, University of Chicago. His residency in internal medicine was at University of Texas Health Science Center in San Antonio, TX. He completed his training with a fellowship in Nephrology at the University of Texas Health Science Center in San Antonio, TX, in 1991. During his education, Dr. Butler also was a Commissioned Medical Office for US Public Health Service, Indian Health Service and rendered services at Fort Duchesne HIS Clinic in Fort Duchesne, Utah and Pine ridge Indian Hospital, Pine Ridge, SD where he received an Isolated Hardship Commendation.
Dr. Butler is a founder of Regional Kidney Care, PC which he opened in 1992. He has over twenty-five years of experience in Internal Medicine and Nephrology. He is the Medical Director of Fresenius Medical Center at Kingsport East and West and the Peritoneal Dialysis clinic at West in Kingsport, TN. He has privileges through Ballad Health System at Holston Valley Medical Center, Bristol Regional Medical Center and Indian Path Medical Center. He also has privileges at HealthSouth Rehabilitation Hospital of Kingsport and Select Specialty in Bristol, TN.
Dr. Butler is Board Certified Diplomat in Internal Medicine and Nephrology. He resides in Kingsport with his wife. He has a daughter, Emily Bruno and a son Andrew Butler. He is also a proud Pop-Pop to two beautiful granddaughters. He also enjoys playing and writing music, gardening and hiking.
Dr. Duc Q. Vu is a graduate of Purdue University, West Lafayette, IN after completing a six-year curriculum in four years at the University of Saigon Medical School. He received his medical degree from University of Texas Medical School, San Antonio, TX. He did his internship and residency in internal medicine at the University of Texas Health Science Center. He completed his training with a fellowship in Nephrology at the University of Texas Health Science Center.
Dr. Vu and Dr. Butler joined as partners at Regional Kidney Care, PC in 1992. Dr. Vu has over twenty-five years of experience in Acute and Chronic Kidney Disease. He has privileges through Ballad Health System at Holston Valley Medical Center, Bristol Regional Medical Center and Indian Path Medical Center. He also has privileges at HealthSouth Rehabilitation Hospital of Kingsport and Select Specialty in Bristol, TN
Dr. Vu is Board Certified Diplomat in Internal Medicine and Nephrology. He became a permanent US resident in 1981 and resides in Kingsport, TN. When not taking care of patients, he enjoys martial arts, photography and his family.
Dr. Abrar Ahmad is a graduate of King Edward Medical College, Pakistan. He did his residency in Internal Medicine at University of Arkansas for Medical Sciences and his fellowship training was completed in Nephrology at the University of Arkansas for Medical Sciences in 2005.
Dr. Ahmad has many years' experience in Acute and Chronic Kidney Disease. He has been in medical practice at Regional Kidney Care, PC, since 2005. He is a Medical Director in Norton at the Fresenius Medical Center Dialysis unit. He has hospital privileges through Ballad Health System at Holston Valley Medical Center, Bristol Regional Medical Center and Indian Path Medical Center. He also has privileges at Encompass Rehabilitation Hospital of Kingsport and Select Specialty in Bristol, TN.
Dr. Ahmad is Board Certified Diplomate in Internal Medicine and Nephrology. He resides in Kingsport with his family. He enjoys bike riding and hydroponics gardening.
Dr. Sathieyendran Poobalasingham is a graduate of Rutgers, the State University of New Jersey with honors. He received his medical degree from St. George's University School of Medicine. His residency in internal medicine was at SUNY Upstate Medical University Hospital where he also was the Medicine Chief Resident in 2004-2005. He completed his training with a fellowship in Nephrology at SUNY Upstate Medical University.
Dr. Poobalasingham has fourteen years of experience in Acute and Chronic Kidney Disease. He joined Regional Kidney Care, PC, in 2007. He is Medical Director of the dialysis unit at Fresenius Medical Center in Bristol, TN and the Peritoneal Dialysis Clinic in Bristol, TN. He has privileges through Ballad Health System at Holston Valley Medical Center, Bristol Regional Medical Center and Indian Path Medical Center. He also has privileges at HealthSouth Rehabilitation Hospital of Kingsport and Select Specialty in Bristol, TN.
Dr. Poobalasingham is Board Certified Diplomat in Internal Medicine and Nephrology. He resides in Kingsport with his wife and two children. He enjoys outdoor activities and leisure time with his family.
Dr. Tapasi Saha is a graduate of Mymensingh Medical College Hospital where she obtained her medical degree in 1988. She also had internship at Mymensingh Medical College Hospital and an externship training in Internal Medicine at St. Joseph Mercy Hospital, Pontiac, MI. She did her residency program at Bonsecours Hospital, Gross Pointe, MI an affiliated teaching hospital and completed her training with a fellowship in Nephrology at the University of Missouri-Columbia, Missouri.
Dr. Saha has nineteen years' experience in Acute and Chronic Kidney Disease. After leaving her tenure as Medical Director of ECU Peritoneal Dialysis, she joined Regional Kidney Care, PC, in 2007. She has privileges through Ballad Health System at Holston Valley Medical Center, Bristol Regional Medical Center and Indian Path Medical Center. She also has privileges at HealthSouth Rehabilitation Hospital of Kingsport and Select Specialty in Bristol, TN.
Dr. Saha is Board Certified Diplomat in Internal Medicine and Nephrology. She also received her Fellowship of American Society of Nephrology (F.A.S.N) in 2005. Dr. Saha resides in Kingsport with her husband and two children. She enjoys cooking and writing poetry in her spare time.
Dr. Ashton Breithaupt is a graduate of the University of Pittsburgh. After college she worked as a chemist at Mylan Pharmaceuticals in Morgantown, WV. She received her medical degree from Edward Via College of Osteopathic Medicine in Spartanburg, SC. Her residency in internal medicine and pediatrics at the University of Tennessee Health Science Center in Memphis TN. She stayed at UTHSC to complete her fellowship in nephrology.
After training she worked in Knoxville, TN before joining Regional Kidney Care.
Dr. Breithaupt is board certified in pediatrics, medicine and nephrology. She resides in Bristol, TN with her husband, two kids and dogs. She enjoys sports, shopping and exploring breweries.
Jennifer Crowley-Rodig, MSN, MPH, APN, ANP-BC, received her nursing degree and her Masters of Science in nursing as an Adult Nurse Practitioner, at University of Florida, Gainesville, FL. Prior to that she received a Bachelor's of Science in Biology from Salisbury University, Salisbury, MD., and a Master's in Public Health from Dartmouth Medical School. She received several honors; Sigma Theta Tau, Golden Key, Omicron Delta Kappa, Beta Beta Beta and Phi Eta Sigma both International and National Honor Society.
Jennifer joined Regional Kidney Care, PC in 2016 after practicing as a Nurse Practitioner in Nephrology for Kaiser Permante in Silver Spring, MD. She has prior nursing experience in surgical intensive care, Internal Medicine, Geriatrics and brings with her a valued experience of chronic kidney disease management to the practice.
Jennifer is Board Certified by the American Nurses Credentialing Center. When she is not working she enjoys family time with her husband and three boys. She resides in Johnson City, TN.
Ashley received her nursing degree from East Tennessee State University and her Masters of Science in Nursing from King College.
Ashley joined Regional Kidney Care in February 2020 after practicing as a Nurse Practitioner in Internal Medicine, Long Term Acute Care and Neurosurgery. She has prior nursing experience in critical care and internal medicine. Ashley is board certified with the American Academy of Nurse Practitioners.
When she is not working she enjoys yoga, hiking, and spending time with her husband and 2 dogs. She resides in Johnson City, TN.
Anita Buckle, MSN, APN, ANP-BC, received her Masters of Science Degree as a Family Nurse Practitioner just down the road in Johnson City, TN at East Tennessee State University in 2006. She received her Bachelor of Science in Nursing from Carson-Newman in Jefferson City, TN in 1995.
Anita joined Regional Kidney Care, PC in 2025. Prior to coming to RKC, Anita worked as a nephrology nurse practitioner in Knoxville TN for 19 years until moving with her husband to be closer to her parents. She worked as an RN in emergency medicine and interventional radiology prior to completing her APN training.
Anita is Board Certified by the American Nurses Credentialing Center. She loves making new memories with her husband, family and friends, and of course her two dogs. She will jump at any chance to travel, especially to a tropical island beach. She resides in Morristown, TN
Wesley Stickley, MSN, APN, APN-BC, was born and raised in Marion, VA. Wesley received his Associates in Nursing from Virginia Highlands Community College, Abingdon, VA. He went on to receive his Bachelor’s in Nursing and Master’s in Nursing with a focus in Family Nurse Practitioner from Bluefield University, Bluefield, VA.
Wesley joined Regional Kidney Care, PC in 2021. Prior to his career as a Nurse Practitioner, he originally worked at Bristol Regional Medical Center on the cardiac step-down unit and later transitioned to the cardiac intensive care unit at Bristol. He advanced to become the Medical Emergency Nurse for the hospital and later took on the role of Associate Clinical Leader for the ICUs. From CNA to NP, he brings 10 years of nursing experience with him to the practice.
Wesley is board certified through the American Association of Nurse Practitioners. He resides in Bristol, TN. Outside of work he enjoys hunting, fishing, gardening, and knows his way around the kitchen.
Dr. Clayton Sommers, DNP, AGACNP-BC, is a board-certified Adult-Gerontology Acute Care Nurse Practitioner with a passion for delivering exceptional care to acutely and critically ill adults. He earned his Doctor of Nursing Practice degree from the joint East Tennessee State University–Tennessee Technological University (ETSU–TTU) program, where he focused on advancing evidence-based practice and clinical leadership.
Before transitioning to advanced practice, Dr. Sommers built a strong foundation in critical care nursing. He served as a registered nurse across multiple high-acuity specialties—including the Surgical, Medical, Neuro, and Cardiovascular Intensive Care Units (SICU, MICU, Neuro ICU, CVICU)—and as a Medical Emergency Team (MET) RN, gaining extensive expertise in complex patient management and rapid response.
He later worked with an Organ Procurement Organization (OPO) as a Registered Nurse, coordinating transplant procedures and collaborating with multidisciplinary teams to improve patient outcomes and facilitate life-saving organ donation.
Today, Dr. Sommers combines his diverse clinical background with a commitment to evidence-based, compassionate care. He is dedicated to advancing acute care nursing practice, improving patient outcomes, and mentoring the next generation of healthcare professionals.