Correlation Between Amyloid PET Imaging and Discordant Cerebrospinal Fluid Biomarkers Results in Patients with Suspected Alzheimer’s Disease

Article type: Research Article

Authors: Lojo-Ramírez, Jose Antonio^{a; *} | Guerra-Gómez, Miriam^a | Marín-Cabañas, Alba Marta^b | Fernández-Rodríguez, Paula ^a | Bernal Sánchez-Arjona, María^b | Franco-Macías, Emilio^b | García-Solís, David^a

Affiliations: [a] Department of Nuclear Medicine, Virgen del Rocío University Hospital, Seville, Spain | [b] Memory Unit, Department of Neurology, Virgen del Rocío University Hospital, Seville, Spain

Correspondence: [*] Correspondence to: Jose Antonio Lojo Ramírez, Servicio de Medicina Nuclear, Hospital Universitario Virgen del Rocío, Avda. Manuel Siurot s/n, 41013 Sevilla, España. Tel.: +34 670811606; E-mail: jalojoram@gmail.com; ORCID: 0000-0003-4945-8250

Abstract: Background:Although the concordance between cerebrospinal fluid (CSF) Alzheimer’s disease (AD) biomarkers and amyloid-PET findings is well known, there are no data regarding the concordance of amyloid-PET with inconclusive CSF values of amyloid-β (Aβ)1 - 42 and p-tau for the diagnosis of AD. Objective:To investigate the relationship between the amyloid-PET results with discordant AD biomarkers values in CSF (Aβ1 - 42+/p-tau–or Aβ1 - 42–/p-tau+). Methods:An observational retrospective study, including 62 patients with mild cognitive impairment (32/62) or dementia (30/62), suspicious of AD who had undergone a lumbar puncture to determine CSF AD biomarkers, and presented discordant values in CSF between Aβ1 - 42 and p-tau (Aβ1 - 42+/p-tau–or Aβ1 - 42–/p-tau+). All of them, underwent an amyloid-PET with 18F-Florbetaben. An extensive neuropsychological testing as part of their diagnostic process (MMSE and TMA-93), was performed, and it was also obtained the Global Deterioration Scale. Results:Comparing the discordant CSF results of each patient with the cerebral amyloid-PET results, we found that in the group with Aβ1 - 42+ and p-tau–CSF values, the amyloid-PET was positive in 51.2% and negative in 48.8% of patients, while in the group with Aβ1 - 42–and p-Tau+ CSF values, the amyloid-PET was positive in 52.6% of patients and negative in 47.4% of them. No significant association was found (p = 0.951) between the results of amyloid-PET and the two divergent groups in CSF. Conclusions:No significant relationship was observed between the results of discordant AD biomarkers in CSF and the result of amyloid-PET. No trend in amyloid-PET results was observed in relation to CSF biomarker values.

Keywords: Alzheimer’s disease, amyloid, biomarkers, cerebrospinal fluid, Florbetaben, PET

DOI: 10.3233/JAD-230744

Journal: Journal of Alzheimer's Disease, vol. 97, no. 1, pp. 447-458, 2024