Rapidly progressive dementia

Because distinguishing between the different possible causes of RPD can be clinically challenging, sensitive and specific laboratory testing is needed to quickly reach the correct diagnosis.

Our first-in-class RPD panel combines traditional Alzheimer’s disease biomarker testing with a real-time quaking induced conversion (RT-QuIC) assay that detects prion disease with high diagnostic accuracy, and a clinically validated t-Tau to p-Tau ratio that outperforms other nonspecific neurodegenerative markers.

Key testing

• RPDE | Rapidly Progressive Dementia Evaluation, Spinal Fluid

Advantages

• Available only through Mayo Clinic Laboratories.
• RT-QuIC is the gold-standard, lab-based test for supporting CJD diagnosis.
• Effectively rules out non-prion causes of RPD (specificity >99%).³
• Sensitive and specific seed amplification assay enables detection and identification of pathogenic prion proteins in cerebrospinal fluid (CSF).
• Every sample is screened for the presence of blood interferences that can lead to false-negative results if undetected.
• Includes traditional biomarker analysis that measures beta-amyloid, p-Tau, t-Tau, and clinically relevant biomarker ratios in CSF plus abnormal prion proteins.⁴
• Combined approach improves laboratory efficiency when evaluating atypical cases.
• Competitive turnaround time to results, with negative cases reported in 3–5 days and positive cases reported in approximately 7 days after sample receipt.
• Results reported with interpretive comments.

Related testing

For some patients, RPD is the initial presenting feature of an underlying autoimmune central nervous system disorder. Our comprehensive autoimmune dementia evaluation, when used alongside RPD or CJD testing, enables in-depth understanding to guide result interpretation and identify those patients with a treatable autoimmune CNS disorder.  

• DMC2 | Dementia, Autoimmune/Paraneoplastic Evaluation, Spinal Fluid
• DMS2 | Dementia, Autoimmune/Paraneoplastic Evaluation, Serum

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Creutzfeldt-Jakob disease

In cases where there is high suspicion of human prion disease, our CJD evaluation can assist in quickly supporting the final diagnosis. Both robust and rapid, this panel includes RT-QuIC and the t-Tau to p-Tau ratio and is available only at Mayo Clinic Laboratories.

Key testing

• CJDE | Creutzfeldt-Jakob Disease Evaluation, Spinal Fluid

Advantages

• RT-QuIC is the gold-standard, lab-based test for supporting CJD diagnosis.
• Sensitive and specific seed amplification assay (RT-QuIC) enables detection and identification of pathogenic prion proteins in cerebrospinal fluid (CSF).
• Ensures the highest diagnostic accuracy through inclusion of tests with high clinical sensitivity and specificity.
• Every sample is screened for the presence of blood interferences that can lead to false-negative results if undetected.
• Competitive turnaround time to results, with negative cases reported in 3–5 days and positive cases reported in approximately 7 days after receipt of the sample.
• Performed in-house and includes results with comprehensive, interpretative comments.

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References

1. Day GS, Tang-Wai DF. When dementia progresses quickly: a practical approach to the diagnosis and management of rapidly progressive dementia. Neurodegener Dis Manag. 2014;4(1):41-56. doi:10.2217/nmt.13.75
2. Chitravas N, Jung RS, Kofskey DM, et al. Treatable neurological disorders misdiagnosed as Creutzfeldt-Jakob disease. Ann Neurol. 2011;70(3):437-444. doi:10.1002/ana.22454.
3. Rhoads DD, Wrona A, Foutz A, Blevins J, Glisic K, Person M, Maddox RA, Belay ED, Schonberger LB, Tatsuoka C, Cohen ML, Appleby BS. Diagnosis of prion diseases by RT-QuIC results in improved surveillance. Neurology. 2020 Aug 25;95(8):e1017-e1026. doi:10.1212/WNL.0000000000010086. Epub 2020 Jun 22. PMID: 32571851.
4. Skillbäck T, Rosén C, Asztely F, Mattsson N, Blennow K, Zetterberg H. Diagnostic performance of cerebrospinal fluid total tau and phosphorylated tau in Creutzfeldt-Jakob disease: results from the Swedish Mortality Registry. JAMA Neurol. 2014 Apr;71(4):476-83. doi:10.1001/jamaneurol.2013.6455. PMID: 24566866.