Background A characteristic feature of RA is the presence of autoantibodies (AAB), such as rheumatoid factor (RF) and antibodies against citrullinated peptides (ACPA). RF and ACPA are not only diagnostically helpful but are also prognostic indicators for progression of joint destruction.
Objectives This is an on-going prospective study to investigate the prevalence of AAB in healthy individuals presenting to community health centres and to subsequently determine the incidence of RA in AAB-positive individuals compared to AAB-negative persons over five years considering the presence of certain risk factors.
Methods Blood drawn at the time of the screening examination was anonymously analyzed for the presence of AAB. AAB positive and age and sex matched AAB negative individuals (2 for each AAB positive subject) were enrolled for further assessment at the central outpatient clinic and examined every 6 months over 5 years. Assessment included laboratory testing (AAB, acute phase parameters), questionnaires on nutrition, lifestyle and general health, 28 joint counts (SJC28, TJC28), the health assessment questionnaire (HAQ), and visual analogue scales for pain and global health. Risk factors were analysed by clusters according to EULAR recommendations for terminology of individuals at risk of RA: hereditary, environmental, systemic autoimmunity and unclassified arthritis and the number of clusters per individual was reported at baseline (1). The primary outcome was the development of RA; individuals lost to follow up were telephone-interviewed for signs and symptoms of RA.
Results 4858 sera were obtained from which 148 (3%) were seropositive (14 ACPA, 124 RF, 10 both). 113 individuals (2,3%) were followed over 5 years. 37 (32,7%) were seropositive of whom 32 (28,3%) were RF-positive, 2 (5,4%) were ACPA-positive and 3 (8,1%) positive for both. We found no significant differences in demographics and risk factors between seropositive and seronegative individuals at baseline (Table 1). The number of risk clusters per individuals is reported in figure 1. Until now, 43 people were followed for 5 years; additional 52 telephone interviews were conducted. No evidence of RA (clinically or by history) was found.
Conclusions By now none of the followed individuals had any evidence of inflammatory joint disease based on patient-telephone interviews conducted and completed 5-year follow-up examinations. We were unable to find evidence for practical value of routine AAB screening in healthy individuals without clinical signs of inflammatory joint diseases.
Gerlag et al. (2012) Ann Rheum Dis 2012;71:638–641.
Disclosure of Interest None declared