According to results of a study, an increase of certain molecules (cytokines and chemokines involved in the functioning of the immune system) can predict the development of rheumatoid arthritis three years before the onset of symptoms.
Rheumatoid arthritis is a form of arthritis that causes pain, swelling, stiffness and loss of function in the joints. Rheumatoid arthritis can affect any joint but is most common in the wrist and fingers.
The study results showed that increased levels of certain cytokines (specifically Th1, Th2 and Treg) involved in the growth and proliferation of various cells integral to the immune system, predicted which individuals go on to develop rheumatoid arthritis.
Interestingly, post-disease onset, chemokines, stromal cell and angiogenic-related markers were important in differentiating up-regulation in those who had developed rheumatoid arthritis compared to findings in the same individual before symptoms of rheumatoid arthritis.
Cytokines and chemokines are small signalling molecules which are integral to the immune system, as they mediate and regulate immunity, inflammation, and the development of blood cells (haematopoiesis). In this study, several of these molecules, as well as some cytokine receptors, showed significantly increased levels before rheumatoid arthritis onset compared with controls (median 3.3 years before symptoms), indicating general immune activation (p<0.05-0.001) and therefore a progression of rheumatoid arthritis activity.
The levels were seen to be particularly elevated in individuals identified as being ACPA- (anti-citrullinated peptide antibody) and RF- (rheumatoid factor) positive (both known risk factors for rheumatoid arthritis), and most of the concentrations increased further after disease onset. Notably, the concentration of interleukin 17 (IL-17, a cytokine which acts as a regulator of multiple immune functions) was found to be significantly higher before onset compared with post-diagnosis (p>0.01).
Prof Solbritt Rantapää Dahlqvist, who led the study said: “Our findings add another important piece to the complex puzzle of pathophysiological processes responsible for the occurrence of rheumatoid arthritis. Understanding more about what happens in the body, to precipitate the onset of rheumatoid arthritis, could potentially contribute to the development of new strategies for the treatment and even prevention of this debilitating disease.”
References:
1. Solbritt Rantapää Dahlqvist, et al. European League Against Rheumatism.
