Background: Blood-based biomarkers (BBM) and visual atrophy scales (VAS) derived from magnetic resonance imaging (MRI) are contemporary tools for dementia diagnosis. Establishing their correlation is essential to optimize clinical practice, especially in low-and middle-income countries, where access to plasma markers is limited. We aimed to evaluate the correlation between BBM and multiple VAS.
Methods: This is a cross-sectional study, using data from the Cog-Aging cohort (2019-2024). Participants (n=28) underwent a comprehensive clinical, neuropsychological and neuroimaging assessment, and had plasma collected within 6 months of MRI. BBM (pTau-217, Aβ42, Aβ40, GFAP, and NfL) were quantified using single-molecule array technology (Simoa®). MRIs were assessed by two independent physicians, using the Entorhinal Cortical Atrophy (ERICA) scale, the Medial Temporal Lobe Atrophy (MTA) scale, the Posterior Atrophy Scale (Koedam) and the White Matter Lesion Scale (Fazekas). Spearman's correlation was used to associate each VAS final score, BBM levels, age and creatinine clearance. Those with significant correlations were further assessed using a Generalized Linear Model (GLM).
Results: Participants had a mean of 75.79 (SD 8.49) years and 42.8% were female. MTA score had a significant positive correlation with GFAP (rho=0.478; p=0.010), NfL (rho=0.412; p=0.029) and age (rho=0.376, p=0.049). ERICA score demonstrated a significant positive correlation with GFAP (rho=0.489, p=0.008), pTau-217 (rho=0.410, p=0.030) and NfL (rho=0.398, p=0.036). Koedam score also had a significant positive correlation with pTau-217 (rho=0.381; p=0.045) and GFAP (rho=0.400; p=0.035) (Figure 1). In GLM analyses, MTA and ERICA scores were not independently associated with NfL (p=0.181 and p=0.398, respectively). MTA score was significantly associated with GFAP levels after adjustment for age (β=0.341; p=0.010). ERICA score were also significantly associated with GFAP levels (β=0.411; p = 0.002), whereas Koedam score was not associated with GFAP (β=0.264; p=0.114). In pTau-217 models, both ERICA (β=0.380; p=0.020) and Koedam scores (β=0.386; p=0.006) showed significant associations (Table 1).
Conclusion: MRI visual atrophy scales correlated with BBM, particularly GFAP and pTau-217. These findings support a possible complementary use of VAS and BBM to enhance dementia diagnosis. These are preliminary results and more studies are necessary.