Andrew Mammen, M.D., Ph.D.

Senior Investigator

Muscle Disease Unit


Building 50, Room 1146
50 South Drive
Bethesda, MD 20814


Research Topics

Dr. Andrew Mammen and researchers at the Muscle Disease Unit (MDU) study myositis, a family of autoimmune diseases that affect skeletal muscle and, in many cases, other organs such as the skin, lungs, and joints. These diseases include dermatomyositis, polymyositis, immune-mediated necrotizing myopathy, and inclusion body myositis. Members of the MDU direct their efforts towards understanding the classification, natural history, and pathologic mechanisms of these diseases with the goal of improving diagnostic and treatment strategies. Current projects include the following:

  • Defining the different subtypes of autoimmune muscle disease based on muscle histology, autoantibodies, and other biomarkers.
  • Elucidating the role of myositis autoantibodies in the pathogenesis of myositis.
  • Developing animal models of myositis that are relevant to the human diseases.
  • Understanding how environmental exposures, including medications such as statins and cancer immunotherapies, can trigger autoimmune muscle disease.
  • Using novel therapeutic strategies to treat myositis patients at the NIH Clinical Center.


After obtaining his M.D. and Ph.D. at Johns Hopkins, Dr. Mammen completed his neurology residency and neuromuscular fellowship at the same institution. He co-founded the Johns Hopkins Myositis Center in 2007. He and his colleagues discovered a novel form of autoimmune myopathy associated with statin use and autoantibodies recognizing HMG-CoA reductase, the pharmacologic target of statins. In 2014, Dr. Mammen moved to the NIH, where he is an Investigator and Leader of the Muscle Disease Unit. In addition to seeing myositis patients at the NIH Clinical Center, he maintains an appointment as Adjunct Professor of Neurology and Medicine at Hopkins, where he continues to see patients at the Myositis Center.

Selected Publications

  1. Pinal-Fernandez I, Casal-Dominguez M, Derfoul A, Pak K, Miller FW, Milisenda JC, Grau-Junyent JM, Selva-O'Callaghan A, Carrion-Ribas C, Paik JJ, Albayda J, Christopher-Stine L, Lloyd TE, Corse AM, Mammen AL. Machine learning algorithms reveal unique gene expression profiles in muscle biopsies from patients with different types of myositis. Ann Rheum Dis. 2020;79(9):1234-1242.
  2. Pinal-Fernandez I, Quintana A, Milisenda JC, Casal-Dominguez M, Muñoz-Braceras S, Derfoul A, Torres-Ruiz J, Pak K, Dell'Orso S, Naz F, Gutierrez-Cruz G, Milone M, Shelly S, Duque-Jaimez Y, Tobias-Baraja E, Matas-Garcia A, Garrabou G, Padrosa J, Ros J, Trallero-Araguás E, Walitt B, Christopher-Stine L, Lloyd TE, Zhao C, Swift S, Rajan A, Grau-Junyent JM, Selva-O'Callaghan A, Liewluck T, Mammen AL. Transcriptomic profiling reveals distinct subsets of immune checkpoint inhibitor induced myositis. Ann Rheum Dis. 2023;82(6):829-836.
  3. Hosono Y, Sie B, Pinal-Fernandez I, Pak K, Mecoli CA, Casal-Dominguez M, Warner BM, Kaplan MJ, Albayda J, Danoff S, Lloyd TE, Paik JJ, Tiniakou E, Aggarwal R, Oddis CV, Moghadam-Kia S, Carmona-Rivera C, Milisenda JC, Grau-Junyent JM, Selva-O'Callaghan A, Christopher-Stine L, Larman HB, Mammen AL. Coexisting autoantibodies against transcription factor Sp4 are associated with decreased cancer risk in patients with dermatomyositis with anti-TIF1γ autoantibodies. Ann Rheum Dis. 2023;82(2):246-252.
  4. Pinal-Fernandez I, Milisenda JC, Pak K, Muñoz-Braceras S, Casal-Dominguez M, Torres-Ruiz J, Dell'Orso S, Naz F, Gutierrez-Cruz G, Duque-Jaimez Y, Matas-Garcia A, Padrosa J, Garcia-Garcia FJ, Guitart-Mampel M, Garrabou G, Trallero-Araguás E, Walitt B, Paik JJ, Albayda J, Christopher-Stine L, Lloyd TE, Grau-Junyent JM, Selva-O'Callaghan A, Mammen AL. Transcriptional derepression of CHD4/NuRD-regulated genes in the muscle of patients with dermatomyositis and anti-Mi2 autoantibodies. Ann Rheum Dis. 2023;82(8):1091-1097.
  5. Mammen AL. Statin-Associated Autoimmune Myopathy. N Engl J Med. 2016;374(7):664-9.

Related Scientific Focus Areas

This page was last updated on Tuesday, August 8, 2023