Disfunção cognitiva no lúpus eritematoso sistêmico: um estudo comparativo com artrite reumatoide e possíveis biomarcadores

Abstract

Cognitive dysfunction is the most common neuropsychiatric manifestation of Systemic Lupus Erythematosus (SLE). Numerous biomarkers have been investigated in an attempt to identify an association with neuropsychiatric symptoms, including cognitive dysfunction. Other autoimmune diseases also present with cognitive symptoms, including Rheumatoid Arthritis (RA), and an increasing number of studies have investigated the cognitive dysfunction in these patients, highlighting the potential pathogenic role of various clinical, psychological and biological factors, similar to SLE. Considering the absence of defined biomarkers in the literature related to cognitive dysfunction in both diseases, we conducted a cross-sectional study with the aim of characterizing cognitive dysfunction in SLE patients and comparing it with RA patients and healthy controls, as well as evaluating the association between possible biomarkers (IL-6, S100B, myeloperoxidase-MPO, malondialdehyde-MDA, reduced glutathione - GSHr), cardiovascular risk factors, disease activity (via DAS-28 and SLEDAI scores) and quality of life (via SF-36) with cognitive dysfunction. In a cross-sectional study, 50 SLE patients, 29 RA patients and 32 healthy controls were included. In the LES group, a higher SLEDAI and higher titles of IL-6 were correlated with poor performance in selective attention, mental flexibility and inhibitory control. Also in the SLE group, MPO titles were correlated with poor performance in logical reasoning and abstraction, and GSHr, a protective factor against oxidative stress, was positively correlated with a better performance in verbal episodic memory. Corticosteroid use in SLE patients was correlated with poor performance in verbal episodic memory, constructive praxis, planning, visuospatial organization, selective attention, mental flexibility and inhibitory control. In the RA group, only disease activity was correlated with poor performance in phonemic fluency. We concluded in the present study that in SLE patients, disease activity, inflammatory state and oxidative stress were associated with cognitive dysfunction. Regarding RA patients, we found that cognitive impairment can be correlated only with disease activity, with no association with biomarkers in our sample. Further studies are needed in order to better investigate possible biomarkers of cognitive dysfunction in patients with autoimmune disease, particularly markers of oxidative stress in patients with SLE