Primary prevention of rheumatoid arthritis.

Rheumatoid arthritis (RA) has a preclinical phase. Before the disease manifests itself autoantibodies such as rheumatoid factor (RF) and antibodies against citrullinated proteins (anti-CCP) can be found. In one half of blood donors who developed RA later we found an elevated concentration in serum of RF and/or anti-CCP at an average of five years before the start of the symptoms, whereas control donors hardly had positive results.
The predictive value for the development of RA within five years of a positive test for RF and/or anti-CCP varies from 2% (no risk factors) to 44% (multi-case families). This risk increases further if the genetic risk factor HLA-DR4 is also present. The target group for this study consists of persons with or without joint complaints (possibly with family members with RA), but without
arthritis, and also with both increased values of RF and/or anti-CCP and a positive test for HLA-DR4. These persons have an increased risk of developing RA and therefore can be considered candidates for a preventive intervention.
Such a preventive intervention should be short and safe. Therefore the choice was made for 1-2 injections with a prednisone-like substance, with proven efficacy in patients who already have RA. The goal of this preventive intervention is to achieve a decrease into the normal range or at least a 50% decrease of the concentration of these antibodies after 6 months. It is expected that a decrease of the antibody concentration is a good predictor for the cancellation or the postponement of
the development of manifest RA.
In this doubleblind randomised study one hundred persons will be included. These will mainly be family members of RA patients and patients with joint complaints who have been referred by their family physician. After the intervention the participants will be followed for at least five years.

1-2 intramuscular injections with 100 mg dexamethason in persons without arthritis but with elevated serum levels of rheumatoid factor and or anti-CCP will lead to a reduction in antibody concentrations after 6 months and possibly to a lower frequency of rheumatoiud arthritis after 5 years, in comparison to no treatment.

1-2 intramuscular injections with 100 mg dexamethason with 6 weeks interval (2nd injection with verum depends on response to first injection) or twice placebo.