title: A test for Creutzfeldt-Jakob disease using nasal brushings.
abstract: BACKGROUND
  Definite diagnosis of sporadic Creutzfeldt-Jakob disease in living patients remains a challenge. A test that detects the specific marker for Creutzfeldt-Jakob disease, the prion protein (PrP(CJD)), by means of real-time quaking-induced conversion (RT-QuIC) testing of cerebrospinal fluid has a sensitivity of 80 to 90% for the diagnosis of sporadic Creutzfeldt-Jakob disease. We have assessed the accuracy of RT-QuIC analysis of nasal brushings from olfactory epithelium in diagnosing sporadic Creutzfeldt-Jakob disease in living patients.
  
  
  METHODS
  We collected olfactory epithelium brushings and cerebrospinal fluid samples from patients with and patients without sporadic Creutzfeldt-Jakob disease and tested them using RT-QuIC, an ultrasensitive, multiwell plate-based fluorescence assay involving PrP(CJD)-seeded polymerization of recombinant PrP into amyloid fibrils.
  
  
  RESULTS
  The RT-QuIC assays seeded with nasal brushings were positive in 30 of 31 patients with Creutzfeldt-Jakob disease (15 of 15 with definite sporadic Creutzfeldt-Jakob disease, 13 of 14 with probable sporadic Creutzfeldt-Jakob disease, and 2 of 2 with inherited Creutzfeldt-Jakob disease) but were negative in 43 of 43 patients without Creutzfeldt-Jakob disease, indicating a sensitivity of 97% (95% confidence interval [CI], 82 to 100) and specificity of 100% (95% CI, 90 to 100) for the detection of Creutzfeldt-Jakob disease. By comparison, testing of cerebrospinal fluid samples from the same group of patients had a sensitivity of 77% (95% CI, 57 to 89) and a specificity of 100% (95% CI, 90 to 100). Nasal brushings elicited stronger and faster RT-QuIC responses than cerebrospinal fluid (P<0.001 for the between-group comparison of strength of response). Individual brushings contained approximately 10(5) to 10(7) prion seeds, at concentrations several logs10 greater than in cerebrospinal fluid.
  
  
  CONCLUSIONS
  In this preliminary study, RT-QuIC testing of olfactory epithelium samples obtained from nasal brushings was accurate in diagnosing Creutzfeldt-Jakob disease and indicated substantial prion seeding activity lining the nasal vault. (Funded by the Intramural Research Program of the National Institute of Allergy and Infectious Diseases and others.).
authors.affiliation: From the Laboratory of Persistent Viral Diseases, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health, Hamilton, MT (C.D.O., M.B., A.G.H., B.R.G., B.C.); and the Department of Biomedical Sciences, University of Cagliari, Cagliari (C.D.O.), the Department of Neurologic and Movement Sciences, University of Verona, Verona (M.B., S.F., M.F., S.M., G.Z.), Clinica Otorinolaringoiatrica, Policlinico G.B. Rossi, Azienda Ospedaliera Universitaria Integrata, Verona (G.T.), and the Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità, Rome (M.P.) - all in Italy.
authors.forename: Christina D
authors.initials: CD
authors.lastname: Orrú
authors.forename: Matilde
authors.initials: M
authors.lastname: Bongianni
authors.forename: Giovanni
authors.initials: G
authors.lastname: Tonoli
authors.forename: Sergio
authors.initials: S
authors.lastname: Ferrari
authors.forename: Andrew G
authors.initials: AG
authors.lastname: Hughson
authors.forename: Bradley R
authors.initials: BR
authors.lastname: Groveman
authors.forename: Michele
authors.initials: M
authors.lastname: Fiorini
authors.forename: Maurizio
authors.initials: M
authors.lastname: Pocchiari
authors.forename: Salvatore
authors.initials: S
authors.lastname: Monaco
authors.forename: Byron
authors.initials: B
authors.lastname: Caughey
authors.forename: Gianluigi
authors.initials: G
authors.lastname: Zanusso
mesh_terms: D000368:Aged; D001921:Brain / Q000473:pathology; D007562:Creutzfeldt-Jakob Syndrome / Q000175:diagnosis*; D004848:Epithelium / Q000737:chemistry; D005260:Female; D005453:Fluorescence; D006801:Humans; D007201:Indicator Dilution Techniques; D008297:Male; D008875:Middle Aged; D009297:Nasal Mucosa / Q000737:chemistry*; D011328:Prions / Q000032:analysis* / Q000134:cerebrospinal fluid; D012680:Sensitivity and Specificity
chemical_list: D011328:Prions
references.citation: Nature. 1994 Aug 11;370(6489):471-4
references.pmid: 7913989
references.citation: J Virol. 2007 May;81(9):4482-91
references.pmid: 17301140
references.citation: N Engl J Med. 2003 Feb 20;348(8):711-9
references.pmid: 12594315
references.citation: Ann Neurol. 2004 Feb;55(2):294-6
references.pmid: 14755736
references.citation: Lancet Neurol. 2012 Jul;11(7):618-28
references.pmid: 22710755
references.citation: Proc Natl Acad Sci U S A. 1998 Nov 10;95(23):13363-83
references.pmid: 9811807
references.citation: Ann Neurol. 2012 Aug;72(2):278-85
references.pmid: 22926858
references.citation: J Virol. 2012 Dec;86(23):12731-40
references.pmid: 22973025
references.citation: J Neurol Neurosurg Psychiatry. 1992 Mar;55(3):181-4
references.pmid: 1564476
references.citation: J Clin Microbiol. 2012 Apr;50(4):1464-6
references.pmid: 22238438
references.citation: Nat Med. 2011 Feb;17(2):175-8
references.pmid: 21278748
references.citation: J Biol Chem. 2010 May 7;285(19):14083-7
references.pmid: 20304915
references.citation: Neurology. 2005 May 10;64(9):1586-91
references.pmid: 15883321
references.citation: Brain Pathol. 1995 Oct;5(4):459-66
references.pmid: 8974629
references.citation: Annu Rev Biochem. 2009;78:177-204
references.pmid: 19231987
references.citation: Science. 2004 Jul 30;305(5684):673-6
references.pmid: 15286374
references.citation: Cell. 2005 Apr 22;121(2):195-206
references.pmid: 15851027
references.citation: Med Clin North Am. 2013 May;97(3):363-8
references.pmid: 23642575
references.citation: PLoS Pathog. 2010 Dec 02;6(12):e1001217
references.pmid: 21152012
references.citation: Science. 2010 Feb 26;327(5969):1132-5
references.pmid: 20110469
references.citation: Ann Neurol. 1994 May;35(5):513-29
references.pmid: 8179297
references.citation: J Virol. 2012 Feb;86(3):1777-88
references.pmid: 22130543
references.citation: J Biol Chem. 2006 Nov 17;281(46):35245-52
references.pmid: 16982620
references.citation: Acta Neuropathol. 2012 Oct;124(4):517-29
references.pmid: 22744790
references.citation: J Virol. 2013 Feb;87(3):1890-2
references.pmid: 23175370
references.citation: Brain. 2009 Oct;132(Pt 10):2659-68
references.pmid: 19773352
references.citation: Mol Med. 2001 Oct;7(10):679-84
references.pmid: 11713367
references.citation: Stat Med. 1998 Apr 30;17(8):857-72
references.pmid: 9595616
references.citation: Acta Neuropathol. 2010 Feb;119(2):177-87
references.pmid: 20052481
references.citation: PLoS Pathog. 2010 Apr 15;6(4):e1000837
references.pmid: 20419120
references.citation: PLoS Pathog. 2011 Jan 13;7(1):e1001257
references.pmid: 21249178
references.citation: J Gen Virol. 2010 Jun;91(Pt 6):1651-8
references.pmid: 20164261
references.citation: Mov Disord. 2013 Apr;28(4):504-9
references.pmid: 23436751
references.citation: Emerg Infect Dis. 2012 Jun;18(6):901-7
references.pmid: 22607808
references.citation: Brain. 2006 Sep;129(Pt 9):2288-96
references.pmid: 16720682
references.citation: Proc Natl Acad Sci U S A. 2007 Jun 5;104(23):9741-6
references.pmid: 17535913
references.citation: Acta Neuropathol. 2011 Jan;121(1):135-43
references.pmid: 20535485