Early detection of patients at risk for rheumatoid arthritis

Abstract

Rheumatoid arthritis (RA) is a systemic auto-immune disease mainly characterized by articular manifestations [1]. Patients present initially with synovitis and joint damage, while extra-articular manifestations such as vasculitis, pleuritis and pericarditis are manifestations of severe or longstanding disease [1,2]. The prevalence of RA is approximately 1% [2]. It affects most patients in the fifth decade of life with females more affected than males [2]. The etiopathogenesis is not fully understood. Genetic, epigenetic and environmental factors seem to play a role [3,4]. Before the articular manifestations other features of RA can already be present. Nielen et al showed in a retrospective cohort of RA patient that donated blood that 49% of the patients were positive for anti-citrullinated protein antibody’s (ACPA’s) and rheumatoid factor (RF) up to 15 years before onset of symptoms [5]. This suggests that the disease develops in different stages which was recently depicted by Hazes and Luime [6,7]. They illustrated RA as stages of plant growth, see figure 1. In the pre-articular phase, all the genetic potential for the development of RA is present, but there are no signs or symptoms of disease. This stage can than develop into an arthralgia phase in which clinically objective synovitis is still not present. In the first clinical phase, symptoms and signs of synovitis indicate the presence of inflammatory arthritis but the form of arthritis is not classifiable and the arthritis is hardly discernable from other inflammatory rheumatic diseases. In the next clinical phase, the disease develops and shows more features of its definite form, and in the third clinical phase the arthritis is fully classifiable as RA [6].