Mariana Castells, M.D., Ph.D. is a clinician/researcher at Brigham and Women's Hospital and Dana Farber Cancer Institute. She is the Director of the Drug Hypersensitivity and Drug Desensitization Center and of the Mastocytosis Center and has served as the Allergy and Clinical Immunology Training Program Director for over 20 years.

Dr. Castells has spearheaded the evaluation and understanding of anaphylaxis and drug hypersensitivity and developed desensitization protocols which are used as standards around the world, treating thousands of patients with cancer and chronic inflammatory diseases, maintaining these patients on first line therapy. She sees and treat patients with drug allergy, anaphylaxis, mast cell activation disorders, urticaria, immune deficiencies, regular food and environmental allergies and asthma.

Her research has uncovered mast cell inhibitory mechanisms which are pertinent to desensitization and her laboratory is actively pursuing pharmacological candidates to improve the safety and efficacy of desensitizations. She has pioneered the diagnosis and treatment of mast cell activation disorders and mastocytosis and is the PI of clinical trials with Tyrosine Kinase Inhibitors.

Dr Castells served on the Board of Directors of The American Academy of Allergy, Asthma & Immunology (AAAAI). She has been on the Board of Directors for the ABAI, has been at the Editorial Board of the Journal of Allergy and Clinical Immunology (JACI), the JACI In Practice and Annals of Allergy, Asthma and Immunology. She has served at the council of the Collegium Internationale Allergologicum and directs the International Drug Desensitization Meeting (DDIM) in Barcelona, Spain, yearly.