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Agreement between FDG‐PET and CSF biomarkers for AD
Author(s) -
RodrigoHerrero Silvia,
GarciaSolis David,
SanchezArjona Maria Bernal,
FrancoMacías Emilio
Publication year - 2020
Publication title -
alzheimer's and dementia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.713
H-Index - 118
eISSN - 1552-5279
pISSN - 1552-5260
DOI - 10.1002/alz.041487
Subject(s) - medicine , dementia , cognitive impairment , kappa , frontotemporal dementia , nuclear medicine , cerebrospinal fluid , oncology , pathology , disease , linguistics , philosophy
Background NICE 2018 guidelines recommend additional tests for the diagnosis of Alzheimer's disease (AD): FDG‐PET, or CSF biomarkers (T‐tau, P‐tau, Abeta42, Abeta40). If we cannot establish the diagnosis after one of the two tests, we should consider the other one. The objective is to study the agreement between FDG‐PET and CSF for diagnosing AD pathology in Mild Cognitive Impairment (MCI) or Mild Dementia stage (Global Dementia Scale 3‐4). Method We conducted a retrospective analysis of patients from July 2017 to May 2019 at the University Hospital Virgen del Rocio (Southern area of Spain, Andalusia). All patients were diagnosed with MCI (GDS‐3) or Mild Dementia (GDS‐4). We performed a CSF study ( Abeta42, T‐tau, P‐tau, and ratios; ELISA or automated method‐Elecsys‐) and FDG‐PET (blind to CSF results). We reviewed CSF trough the Biobank database ("Alzheimer's and other dementias") and FDG‐PET results from clinical database Histories. We classified CSF results as "positive CSF‐AD," or "negative CSF‐AD," following recommended cut‐off points. The classification of FDG‐PET was as well positive or negative, according to the presence or absence of typical AD hypometabolism. We studied the agreement between CSF and FDG‐PET with contingency tables and the Kappa index. Result We included 58 cases in the analysis. The mean age was 65.93 ± 8.38 years (range 51‐82); 31 (53.4%) females, 27 (46.6%) males. The average score in MMSE was 21.36 ± 4.68. The agreement was high‐grade (Kappa index = 0.60). 35 out of 39 cases with "positive CSF AD" had "positive FDG‐PET." 13 out of 19 cases with "negative CSF AD" had "negative FDG‐PET." There was disagreement in 10 cases, possibly due to false‐negative CSF, false‐positive FDG‐PET, or false‐negative FDG PET. Conclusion Despite not being a biomarker of the pathophysiology of AD, PET FDG has a diagnostic recommendation (NICE Guidelines 2018; Andriuta et al. J Alzheimers Dis. 2016). In this study, concordance with biomarkers in CSF was high‐rated, as shown in previous studies (Rubi S. et al. Rev Esp Med Nucl Imagen 2018). However, in 10 of the 58 cases, we had disagreements, supporting the recommendation to perform both CSF and FDG‐PET in doubt diagnoses.