Mammana A et al. 2020, Detection of prions in skin punch biopsies of Creutzfeldt-Jakob disease patients (Ann Clin Transl Neurol 7(4):559-564, PMID 32141717, doi 10.1002/acn3.51000)

A 2020 brief report from the Bologna neurological sciences institute, with a senior contributor from NIAID Rocky Mountain Laboratories, tested 3 mm skin punch biopsies from 35 people with CJD and 37 without prion disease using RT-QuIC. With a bank vole recombinant substrate the test was 89 percent sensitive and 100 percent specific, and it worked in the five people sampled in life. It is the main evidence base for skin punch RT-QuIC as a less invasive test.

Key facts

  • Citation verified: Ann Clin Transl Neurol 2020, volume 7, issue 4, pages 559-564, PMID 32141717, PMC7187701, DOI 10.1002/acn3.51000, brief report with eight authors and Piero Parchi as last author.
  • Design: 71 punch biopsies from 35 CJD patients (29 definite and 3 probable sporadic, 3 genetic, five of them sampled in life) against 37 non-CJD controls, of whom 22 were suspected cases negative for prions at autopsy and 15 had other neurological conditions.
  • Two sites were sampled with a 3 mm punch: the C7 paravertebral area and the lateral thigh.
  • Specificity was 100 percent with both substrates (no false positives in 37 controls); sensitivity was 68.6 percent with hamster PrP and 88.6 percent with bank vole PrP.
  • Seeding in skin appeared strain dependent: VV2, MV2K and E200K genetic cases were consistently positive and gave stronger signal than typical MM1, which was 85 percent positive at the cervical site and 68 percent at the thigh. Non-MM1 numbers were small.
  • All five sporadic CJD patients sampled in life were positive at one or both sites, and the cervical site gave the more consistent response.
  • The authors state limits: few non-MM1 cases, only five in-life cases, speculative strain interpretation, and no information on infectivity or transmission risk.
  • Funding was from the Italian Ministry of Health (grant RF-2016-02364498); one author (Caughey) discloses patents on RT-QuIC assays.

Timeline

  1. 2019Manuscript received by the journal.
  2. 2020Manuscript accepted.
  3. 2020Published online.
  4. 2020Print issue (volume 7, issue 4).

Last checked 1 November 2026

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