Papel dos autoanticorpos contra proteínas do sistema nervoso no desempenho cognitivo de pacientes com artrite reumatoide

Abstract

Rheumatoid arthritis (RA) is a chronic autoimmune and inflammatory disease characterized by the production of autoantibodies and the articular and extra articular events, including the Central Nervous System (CNS) of patients. Factors such as the chronic inflammation and the presence of autoantibodies against myelin proteins are potential mechanisms involved with cognitive dysfunction in other autoimmune diseases. Disorders such as mild cognitive impairment and Alzheimer's disease have high plasma levels of autoantibodies against myelin proteins well as important cognitive impairment and increased levels of S100β protein. Based on this, here we explore the relationship between cognitive performance, plasma levels of antibodies and S100β protein of patients with RA. Twenty patients with RA and nineteen healthy controls did not differ significantly by gender, age and schooling, were recruited in this study. Cognitive function, (MMSE, working memory, processing speed, inhibitory control and mental flexibility) declarative memory and depression were assessment through interviews where specific clinical questionnaires were apply. The plasma of patients and controls was obtained by centrifugation to investigate the levels of S100β protein and autoantibodies against Basic Myelin Protein (English MBP - Myelin Basic Protein) and against Glycoprotein Myelin oligodendrocyte (English MOG Myelin Oligodendrocyte Glycoprotein). RA patients had a lower cognitive performance in the MMSE, declarative memory, working memory, processing speed, inhibitory control and mental flexibility compared to healthy controls. Patients present S100β protein levels and anti - MBP and anti - MOG higher than controls which negatively correlated with cognitive performance of these individuals. In regression analyzes peripheral levels of anti - MOG and anti - MBP acted as predictors of executive function scores as declarative and working memory, processing speed and inhibitory capacity. In conclusion, when compared to healthy controls, RA patients have higher serum levels of autoantibodies and S100β protein which were negatively related and predicted the worst cognitive performance of these individuals.