Detection S100B, P-Tau and Aβ1-42 proteins in the plasma of rheumatoid arthritis patients with mild cognitive impairment

Abstract

Objective To investigate the plasma protein concentration of S100B protein, hyperphos-phorylated tau protein (P-tau) and β-amyloid (Aβ1-42) of rheumatoid arthritis (RA) patients with mild co- gnitive impairment (MCI) and to provide a reference for clinical diagnosis and prevention of cognitive dysfunction of RA patients. Methods The subjects were consisted of three groups: RA patients with MCI, RA patients with normal cognitive function (NC) and healthy controls. The Montreal Cognitive Assessment (MoCA) was used to test patients' cognitive function, generalized anxiety disorder scale-7 (GAD-7) scale and 9-item patient health questionnaire-9 (PHQ-9) were used to exclude anxiety and depression of RA patients. The concentration of S100B protein, P-tau protein and Aβ1-42 protein in plasma was detected by enzyme-linked immunosorbent assay (ELISA), and the correlation among the concentration of S100B protein, P-tau protein and MoCA scores was analyzed by Pearson's chi-squared test. Results ① Cognitive scores showed that some RA patients had MCI. ② The plasma levels of S100B (F=11.81, P<0.05), P-tau (F=3.3, P<0.05) protein in RA patients with MCI were higher than that in NC RA patients and the control group (P<0.05). ③ The clinical index analysis showed that the concentration of C reactive protein (CRP) in RA patients with MCI was higher than that in NC RA patients and healthy control, the difference was statistically significant (t=6.44, P<0.05). ④ The levels of plasma P-tau (r=-0.539, P<0.05), S100B (r=-0.346, P<0.05), CRP (r=-0.358, P<0.05) protein were negatively correlated with cognitive scores (P<0.05). Conclusion CRP, S100B protein and P-tau protein are associated with the pathogenesis of RA patients with MCI. The consequences of plasma concentration test can be com-bined with cognitive assessment questionnaire to provide reference for clinical diagnosis of RA patients with MCI. Key words: Arthritis, rheumatoid; Mild cognitive dysfunction; S100 proteins; Tau proteins; Amyloid beta-protein