title: Clinical ramifications of the MHC family Fc receptor FcRn.
abstract: BACKGROUND
  Knowledge that antibodies of the IgG isotype have remarkably extended persistence in circulation and are able to pass through cell barriers has substantial implications. While it is well established that so-called neonatal Fc receptor, FcRn, acts throughout life to confer these unusual properties, its ramifications on clinical medicine and therapeutic uses are not broadly appreciated.
  
  
  METHODS
  Here we discuss basic principles and gaps in understanding of FcRn, including its management of IgG antibodies and along with albumin, its impact on use and design of antibody-based therapeutics, and its genetics.
authors.affiliation: The Jackson Laboratory, 600 Main Street, Bar Harbor, ME 04609, USA. dcr@jax.org
authors.forename: Derry C
authors.initials: DC
authors.lastname: Roopenian
authors.forename: Victor Z
authors.initials: VZ
authors.lastname: Sun
mesh_terms: D056704:Adaptive Immunity; D000418:Albumins / Q000276:immunology / Q000378:metabolism*; D000818:Animals; D015551:Autoimmunity; D001775:Blood Circulation / Q000276:immunology; D005260:Female; D015395:Histocompatibility Antigens Class I / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology*; D007422:Intestines / Q000276:immunology; D008285:Major Histocompatibility Complex / Q000235:genetics; D010920:Placenta / Q000276:immunology; D021041:Placental Circulation / Q000276:immunology*; D011247:Pregnancy; D015202:Protein Engineering; D011961:Receptors, Fc / Q000276:immunology*
chemical_list: D000418:Albumins; D015395:Histocompatibility Antigens Class I; D007074:Immunoglobulin G; D011961:Receptors, Fc; C100688:Fc receptor, neonatal