Expressão de proteínas reguladoras do complemento CD55, CD59, CD35 e CD46 na artrite reumatoide

Abstract

A artrite reumatoide (AR) e uma doenca autoimune, associada a sinovite poliarticular infl amatoria, que acomete principalmente as articulacoes perifericas. Cerca de 1% da populacao mundial e afetada, sendo duas a tres vezes mais prevalente em mulheres. Apresenta patogenese complexa e multifatorial. A sinovia das articulacoes afetadas e infi ltrada por linfocitos T e B, macrofagos e granulocitos. A sinovia reumatoide adquire caracteristicas proliferativas, formando o pannus, e invade a cartilagem articular e o osso, levando a destruicao da arquitetura normal da articulacao e a perda de funcao. A diminuicao da expressao de proteinas reguladoras do complemento (PCR) parece desempenhar papel importante na atividade da AR, associada ao agravamento dos sintomas clinicos. A superativacao do sistema complemento (SC) e a causa da exacerbacao da doenca em varios modelos de doencas autoimunes. O presente artigo tem por objetivo revisar os principais aspectos relacionados a regulacao do SC na AR, a fi m de propiciar melhor compreensao do potencial papel desse sistema na fi siopatologia e na atividade da doenca.

Rheumatoid arthritis (RA) is an autoimmune disease associated with polyarticular infl ammatory synovitis affecting mainly peripheral joints. It affects approximately 1% of the world population, being two to three times more prevalent in women. Rheumatoid arthritis has a complex and multifactorial pathogenesis. The synovium of the affected joints is infi ltrated by T and B lymphocytes, macrophages, and granulocytes. The rheumatoid synovium has proliferative characteristics, forming the pannus, which invades cartilage and bone, leading to normal architecture destruction and function loss. The decreased expression of complement regulatory proteins (CRP) seems to play an important role in RA activity, and is associated with worsening of the clinical symptoms. In several models of autoimmune diseases, the overactivation of the complement system (CS) is the cause of disease exacerbation. This article aimed at reviewing the main aspects related to CS regulation in RA in order to provide a better understanding of the potential role of this system in the pathophysiology and activity of the disease.