The Correlations of Plasma Liver-Type Fatty Acid-Binding Protein with Amyloid-β and Tau Levels in Patients with Alzheimer's Disease.

BACKGROUND The dysregulation of lipid metabolism plays an important role in the pathogenesis of Alzheimer's disease (AD). Liver-type fatty acid-binding protein (L-FABP, also known as FABP1) is critical for fatty acid transport and may be involved in AD. OBJECTIVE To investigate whether the FABP1 level is altered in patients with AD, and its associations with levels of amyloid-β (Aβ) and tau in the plasma and cerebrospinal fluid (CSF). METHODS A cross-sectional study was conducted in a Chinese cohort consisting of 39 cognitively normal controls and 47 patients with AD. The levels of FABP1 in plasma, and Aβ and tau in CSF, were measured by enzyme-linked immunosorbent assay (ELISA). A single-molecule array (SIMOA) was used to detect plasma Aβ levels. RESULTS The level of plasma FABP1 was significantly elevated in the AD group (p = 0.0109). Further analysis showed a positive correlation of FABP1 with CSF total tau (t-tau) and phosphorylated tau (p-tau) levels. Besides, plasma FABP1/Aβ 42 (AUC = 0.6794, p = 0.0071) and FABP1/t-tau (AUC = 0.7168, p = 0.0011) showed fair diagnostic efficacy for AD. When combined with other common AD biomarkers including plasma Aβ 42, Aβ 40, and t-tau, both FABP1/Aβ 42 and FABP1/t-tau showed better diagnostic efficacy than using these biomarkers alone. Among all AUC analyses, the combination of plasma FABP1/t-tau and Aβ 42 had the highest diagnostic value (AUC = 0.8075, p <  0.0001). CONCLUSION These findings indicate that FABP1 may play a role in AD pathogenesis and be worthy of further investigation in the future.