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Language(s) Spoken

English; Spanish; German

Joined Kelsey-Seybold

June 2011

Accepting New Patients?


​​​​​​​​​​Pro​​fes​​sional Background

After earning a degree in biology and German from Rice University in 1995, Dr. Johnston completed medical school at the National University of Ireland at Cork in 2003. Dr. Johnston completed his residency in Internal Medicine at The University of Texas Medical School at Houston in 2006 and a fellowship in Rheumatology at the University of Washington in Seattle in 2008.

Profes​​​siona​​l Associations

Dr. Johnston is a fellow of the American College of Rheumatology and a member of the American College of Physicians, Osteoarthritis Research Society International, Texas Medical Association and the Harris County Medical Society.

Hobbies ​​​and Interests

When he’s not caring for patients, Dr. Johnston frequently participates in half marathons.​​​​

​I believe that teaching and explaining often complicated diseases and treatments helps my patients and I work together more effectively to improve outcomes.



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Awards & Recognitions


Dr. Johnston’s multiple publications include the following:​
  • Arthritis Rheum (suppl), Genetic predictors of disease damage and activity early in SLE among patients from three ethnic groups., Reveille JD, Johnston KA, Ahn C, Tan FK, Friedman AW, Goel N, Moulds JM, McGwinn G, Roseman J, Alarcon GS., Publication Date: 1998 , Volume: 41, Pages: S283
  • American Society of Human Genetics, Evidence of linkage with specific HLA Class II alleles and Alopecia Areata., de Andrade M, Jackow C, Johnston KA, Reveille JD, & Duvic M, Publication Date: 1997, Volume: [abstract]
  • Johnston KA and Simkin PA. The Tidemark of Cartilage: A Depot for Apoptotic, Debris? A Target for Autoimmune Diesase? 2008 World Congress on OsteoarthritisRome, Italy. #207 [abstract]
  • Johnston KA and Simkin PA. The Tidemark of Cartilage Contains Antigenic Nuclear Debris.  2008 American College of Rheumatology Annual Scientific Meeting, San Francisco, California.  #F13 [abstract]
  • Aslam M. and Johnston K. Use of Rituximab in End-Stage Renal Disease Caused By Cryoglobulinemic Vasculitis: A Case Report.  2011 EULAR Annual European Congress of Rheumatology, London, UK.  EULAR11-1655 [abstract]