The clinical application of optimized AT(N) classification in Alzheimer’s clinical syndrome (ACS) and non-ACS conditions
Kensaku Kasuga, Tamao Tsukie, Masataka Kikuchi, Takayoshi Tokutake, Kazuo Washiyama, Soichiro Shimizu, Hiroshi Yoshizawa, Yasuko Kuroha, Ryuji Yajima, Hiroshi Mori, Yasuaki Arakawa, Kiyoshi Onda, Akinori Miyashita, Osamu Onodera, Takeshi Iwatsubo, Takeshi Ikeuchi
Abstract
We aimed to assess the utility of AT(N) classification in clinical practice. We measured the cerebrospinal fluid levels of amyloid-β (Aβ) 42, Aβ40, phosphorylated tau, total tau, and neurofilament light chain (NfL) in samples from 230 patients with Alzheimer’s clinical syndrome (ACS) and 328 patients with non-ACS. The concordance of two A-markers (i.e., Aβ42 alone and the Aβ42/Aβ40 ratio) was not significantly different between the ACS (87.4%) and non-ACS (74.1%) groups. However, the frequency of discordant cases with AAβ42-alone+/AAβ-ratio− was significantly higher in the non-ACS (23.8%) than in the ACS group (7.4%). The concordance of two N-markers (i.e., total tau and NfL) was 40.4% in the ACS group and 24.4% in the non-ACS group. In the ACS samples, the frequency of biological Alzheimer’s disease (i.e., A+T+) in Ntau+ cases was 95% while that in NNfL+ cases was 65%. Reflecting Aβ deposition and neurodegeneration more accurately, we recommend the use of AT(N) classification defined by cerebrospinal fluid AAβ-ratioTNNfL in clinical practice.