title: Double Seronegative Myasthenia Gravis with Anti-LRP4 Antibodies Presenting with Dropped Head and Acute Respiratory Insufficiency.
abstract: We herein report the case of a 72-year-old man demonstrating myasthenia gravis (MG) with a dropped head and acute respiratory insufficiency. There was no ocular, bulbar, or limb involvement. The patient was seronegative for anti-acetylcholine receptor (AChR) antibodies and anti-muscle-specific tyrosine kinase (MuSK) antibodies. Subsequent tests showed seropositivity for anti-low-density lipoprotein receptor-related protein 4 (LRP4) antibodies. The addition of steroid pulse therapy resulted in a full remission of his respiratory symptoms. This presentation suggests that LRP4-positive MG should be considered in the differential diagnosis of patients presenting with acute respiratory insufficiency without either cranial or limb involvement.
authors.affiliation: Department of Neurology, Osaka University Graduate School of Medicine, Japan.
authors.forename: Goichi
authors.initials: G
authors.lastname: Beck
authors.forename: Taiki
authors.initials: T
authors.lastname: Yabumoto
authors.forename: Kousuke
authors.initials: K
authors.lastname: Baba
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Sasaki
authors.forename: Osamu
authors.initials: O
authors.lastname: Higuchi
authors.forename: Hidenori
authors.initials: H
authors.lastname: Matsuo
authors.forename: Hideki
authors.initials: H
authors.lastname: Mochizuki
mesh_terms: D000208:Acute Disease; D000368:Aged; D003937:Diagnosis, Differential; D006801:Humans; D026502:LDL-Receptor Related Proteins / Q000276:immunology*; D008297:Male; D009157:Myasthenia Gravis / Q000150:complications* / Q000175:diagnosis*; D012131:Respiratory Insufficiency / Q000209:etiology*
chemical_list: D026502:LDL-Receptor Related Proteins; C551781:LRP4 protein, human