Kelch-like Protein 11 Antibodies in Seminoma-Associated Paraneoplastic Encephalitis

N Engl J Med. 2019 Jul 4;381(1):47-54. doi: 10.1056/NEJMoa1816721.


A 37-year-old man with a history of seminoma presented with vertigo, ataxia, and diplopia. An autoantibody specific for kelch-like protein 11 (KLHL11) was identified with the use of programmable phage display. Immunoassays were used to identify KLHL11 IgG in 12 other men with similar neurologic features and testicular disease. Immunostaining of the patient's IgG on mouse brain tissue showed sparse but distinctive points of staining in multiple brain regions, with enrichment in perivascular and perimeningeal tissues. The onset of the neurologic syndrome preceded the diagnosis of seminoma in 9 of the 13 patients. An age-adjusted estimate of the prevalence of autoimmune KLHL11 encephalitis in Olmsted County, Minnesota, was 2.79 cases per 100,000 men. (Funded by the Rochester Epidemiology Project and others.).

Publication types

  • Case Reports
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Autoantibodies / analysis*
  • Brain / immunology*
  • Carrier Proteins / immunology*
  • Cell Surface Display Techniques*
  • Encephalitis / epidemiology
  • Encephalitis / immunology*
  • Hashimoto Disease / epidemiology
  • Hashimoto Disease / immunology*
  • Humans
  • Immunoassay
  • Male
  • Middle Aged
  • Minnesota / epidemiology
  • Paraneoplastic Syndromes, Nervous System / immunology*
  • Prevalence
  • Seminoma / complications*
  • Testicular Neoplasms / complications*


  • Autoantibodies
  • Carrier Proteins
  • KLHL11 protein, human

Supplementary concepts

  • Hashimoto's encephalitis