Combination assay of CSF Tau, Aβ1-40 and Aβ1-42(43) as a biochemical marker of Alzheimer's disease

• Published in: Journal of the neurological sciences Vol. 158; no. 2; pp. 134 - 140
• Main Authors: Shoji, Mikio, Matsubara, Etsuro, Kanai, Mitsuyasu, Watanabe, Mitsunori, Nakamura, Tamiko, Tomidokoro, Yasushi, Shizuka, Masami, Wakabayashi, Katsumi, Igeta, Yukifusa, Ikeda, Yoshio, Mizushima, Kazuyuki, Amari, Masakuni, Ishiguro, Koji, Kawarabayashi, Takeshi, Harigaya, Yasuo, Okamoto, Koich, Hirai, Shunsaku
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier B.V 01.06.1998; Elsevier Science
• Subjects: Alzheimer's disease; Aβ1-40; Aβ1-42; Biological and medical sciences; CSF; Degenerative and inherited degenerative diseases of the nervous system. Leukodystrophies. Prion diseases; Medical sciences; Neurology; Tau; Tau; Aβ1-40; Alzheimer's disease; CSF; Aβ1-42; Human; Nervous system diseases; Alzheimer disease; Biological marker; Cerebrospinal fluid; Subunit; Cerebral disorder; Sensitivity; Specificity; Tau protein; Surveillance; β Amyloid protein; Central nervous system disease; Adult; Degenerative disease; Diagnosis; ELISA assay
• ISSN: 0022-510X; 1878-5883
• DOI: 10.1016/S0022-510X(98)00122-1

Cerebrospinal fluid samples from a total of 157 subjects consisting of 55 patients with sporadic Alzheimer's disease (AD), 34 normal controls, 23 patients with non-AD dementia, and 45 with other neurological diseases were examined by ELISA of tau, Aβ1-40, and Aβ1-42(43). The AD group had a significantly higher level of tau than the normal control group ( P<0.001), and the diagnostic sensitivity was 31% and specificity was 94%. CSF Aβ1-40 levels did not show any significant differences. Although the level of Aβ1-42(43) was decreased significantly in the AD group compared to the control group ( P<0.005), the overlap of Aβ1-42(43) levels among all groups meant that none of the AD samples exceeded the cut-off value, the mean 2SD of normal control subjects. Reduction of Aβ1-42(43) levels in AD resulted in a significant increase in the ratio of Aβ1-40 to Aβ1-42(43) (Aβ ratio) as an improved marker. The diagnostic sensitivity and specificity of Aβ ratio were 51% and 82% respectively. The three indexes, using the tau level and Aβ ratio (tau or Aβ ratio, deviation score and tau×Aβ ratio), showed better sensitivity (58%, 67%, 69%) and specificity (82%, 86%, 88%) than previously reported methods. Combination assay for CSF tau, Aβ1-40 and Aβ1-42(43) in CSF is a biological marker of AD and may be useful to biochemically monitor subjects under treatment.