Application of QPLEXTM biomarkers in cognitively normal individuals across a broad age range and diverse regions with cerebral amyloid deposition

• Published in: Experimental & molecular medicine 2022, 54(0), , pp.1-12
• Main Authors: Lee, Dongjoon, Park, Jong-Chan, Jung, Keum Sim, Kim, Jiyeong, Jang, Ji Sung, Kwon, Sunghoon, Byun, Min Soo, Yi, Dahyun, Byeon, Gihwan, Jung, Gijung, Kim, Yu Kyeong, Lee, Dong Young, Han, Sun-Ho, Mook-Jung, Inhee
• Format: Article
• Language: English
• Subjects: 13/1; 59/78; 631/1647/664/1467; 631/378/1689/1283; 631/378/2611; 82; 82/80; Aging; Alzheimer's disease; Biomarkers; Biomedical and Life Sciences; Biomedicine; Brain; Cognitive ability; Diagnosis; Medical Biochemistry; Molecular Medicine; Neurodegenerative diseases; Stem Cells; β-Amyloid; 생화학
• ISSN: 1226-3613; 2092-6413
• DOI: 10.1038/s12276-021-00719-3

The deposition of beta-amyloid (Aβ) in the brain precedes the onset of symptoms such as cognitive impairment in Alzheimer’s disease (AD); therefore, the early detection of Aβ accumulation is crucial. We previously reported the applicability of the QPLEX TM Alz plus assay kit for the prescreening of Aβ accumulation. Here, we tested the specific application of the kit in a large cohort of cognitively normal (CN) individuals of varying ages for the early detection of Aβ accumulation. We included a total of 221 CN participants with or without brain Aβ. The QPLEX TM biomarkers were characterized based on age groups (1 st –3 rd tertile) and across various brain regions with cerebral amyloid deposition. The 3 rd tertile group (>65 years) was found to be the most suitable age group for the application of our assay kit. Receiver operating characteristic curve analysis showed that the area under the curve (AUC, discrimination power) was 0.878 with 69.7% sensitivity and 98.4% specificity in the 3 rd tertile group. Additionally, specific correlations between biomarkers and cerebral amyloid deposition in four different brain regions revealed an overall correlation with general amyloid deposition, consistent with previous findings. Furthermore, the combinational panel with plasma Aβ1–42 levels maximized the discrimination efficiency and achieved an AUC of 0.921 with 95.7% sensitivity and 67.3% specificity. Thus, we suggest that the QPLEX TM Alz plus assay is useful for prescreening brain Aβ levels in CN individuals, especially those aged >65 years, to prevent disease progression via the early detection of disease initiation. Alzheimer’s disease: a blood test may offer early diagnosis A novel assay kit called QPLEX TM Alz plus assay offers a convenient method for assessing brain levels of the beta-amyloid proteins implicated in Alzheimer’s disease in people with normal cognitive abilities, especially those aged over 65. South Korean researchers led by Inhee Mook-Jung at Seoul National University assessed the efficacy of blood tests using the QPLEX TM kit on 221 participants in the Korean Brain Aging Study for Early Diagnosis and Prediction of Alzheimer’s Disease (KBASE). The researchers developed the assay to identify several circulating biomarkers of brain beta-amyloid accumulation. They found the test can distinguish between people known to either have or not have beta-amyloid deposits in their brain. This suggests QPLEX TM Alz plus assay could offer an improved proced