International Journal of Medicine and Psychology · Apr 24, 2026

Prognostic significance of blood biomarkers for the early diagnosis of Alzheimer's disease at the preclinical stage

By Черепахина А, Игоревич ЧД, Владимирович АП

The article evaluates the prognostic significance of specific plasma protein concentrations (Aβ42, Aβ40, p-tau181, NfL) and determines their accuracy in the early diagnosis of Alzheimer's disease in individuals without clinical signs of cognitive decline. A prospective observational study (2023–2025) was conducted involving 95 individuals aged 55–75 years. Two groups were formed: the main group (Group 1, n=45) comprised individuals with subjective cognitive decline (SCD) and amyloid-positive status (Aβ42/Aβ40 < 0.1); the control group (Group 2, n=50) comprised cognitively healthy volunteers. Laboratory detection of proteins (Aβ40, Aβ42, p-tau181, p-tau217, NfL, GFAP) was performed using the Simoa ultrasensitive immunoassay. The neuropsychological profile was assessed using the MMSE and MoCA scales and the PACC composite index. Statistical analysis was performed in RStudio using Student's and Mann-Whitney tests and Pearson correlation. Statistically significant changes in plasma biochemical homeostasis were identified in participants in the first group. A decrease in the Aβ42/Aβ40 ratio to 0.089±0.007 and a fivefold increase in p-tau217 concentration (1.84±0.62 pg/ml) compared with the control were recorded (p < 0.001). Increased levels of GFAP (175.4±42.8 pg/ml) and NfL (21.3±5.6 pg/ml) confirm the presence of early neuroinflammation and axonal destruction. Neuropsychological testing revealed a latent deficit despite a preserved MMSE total score: decreased MoCA scores (26.1±1.4) and negative PACC index values (-0.42±0.25). A strong correlation was established between the p-tau217 level and episodic memory impairment (r = -0.52). Fluid biomarkers have high prognostic value in identifying the pathological process at the preclinical stage. The combination of a low amyloid index and a high p-tau217 concentration serves as an objective indicator of neurodegeneration preceding clinical manifestation. The use of multimodal plasma protein panels in conjunction with targeted functional tests enables the verification of risk groups and creates conditions for the timely initiation of preventive therapy. the paper the prognostic significance of specific plasma protein concentrations (Aβ42, Aβ40, p-tau181, NfL) is evaluated and their accuracy in the early diagnosis of Alzheimer's disease in individuals without clinical signs of cognitive decline is determined. A prospective observational study (2023–2025) was conducted involving 95 individuals aged 55–75 years. Two groups were formed: the main group (Group 1, n=45) included individuals with subjective cognitive decline (SCD) and amyloid-positive status (Aβ42/Aβ40 < 0.1); the control group (Group 2, n=50) included cognitively healthy volunteers. Laboratory detection of proteins (Aβ40, Aβ42, p-tau181, p-tau217, NfL, GFAP) was performed using the Simoa ultrasensitive immunoassay. Neuropsychological profile was assessed using the MMSE, MoCA, and PACC composite scores. Statistical analysis was performed in RStudio using Student's t-test, Mann-Whitney U tests, and Pearson correlation. Participants in the first group showed statistically significant changes in plasma biochemical homeostasis. A decrease in the Aβ42/Aβ40 ratio to 0.089±0.007 and a fivefold increase in p-tau217 concentration (1.84±0.62 pg/ml) compared to the control (p < 0.001) were recorded. Increased GFAP (175.4±42.8 pg/ml) and NfL (21.3±5.6 pg/ml) levels confirm the presence of early neuroinflammation and axonal destruction. Neuropsychological testing revealed a latent deficit with an intact MMSE total score: decreased MoCA scores (26.1±1.4) and negative PACC index values (-0.42±0.25). A strong correlation was established between p-tau217 levels and episodic memory impairment (r = -0.52). Fluid-based biomarkers have high prognostic value in identifying pathological processes at the preclinical stage. The combination of a low amyloid index and high p-tau217 levels serves as an objective indicator of neurodegeneration preceding clinical manifestation. The use of multimodal plasma protein panels in conjunction with targeted functional assays enables the verification of risk groups and creates the conditions for the timely initiation of preventive therapy.

doi.org/10.58224/2658-3313-2026-9-3-83-94Open accessBiomarkers