INTRODUCTION: Disease activity, severity and co-morbidity contribute to increased mortality in patients with rheumatoid arthritis (RA). We evaluated the impact of age at disease onset on prognostic risk factors and treatment in early disease.
METHODS: In this study, 950 RA patients were followed regularly from inclusion (<12 months from symptom onset) for disease activity (erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), tender/swollen joints, visual analogue scale (VAS) pain/global, disease activity score (DAS28)) and function (health assessment questionnaire (HAQ)). Disease severity, measured by radiographs of hands/feet (erosions, Larsen score), extra-articular disease, nodules and co-morbidities and treatment (disease-modifying anti-rheumatic drugs (DMARDs), corticosteroids, biologics, nonsteroidal anti-inflammatory drugs (NSAIDs)) were recorded at inclusion and after 5 years. Autoantibodies (rheumatoid factor (RF), anti-nuclear antibodies (ANA), antibodies against cyclic citrullinated peptides (ACPA)) and genetic markers (human leukocyte antibody (HLA)-shared epitope, protein tyrosine phosphatase nonreceptor type 22 (PTPN22)) were analyzed at inclusion. Data were stratified as young (YORA) and late (LORA) onset RA, defined as being below/above median age (58 years) at onset.
RESULTS: LORA was associated with lower frequency of ACPA (P <0.05) and carriage of PTPN22-T variant (P <0.01), but with greater disease activity at inclusion measured as ESR (P < 0.001), CRP (P <0.01) and accumulated disease activity (area under the curve for DAS28) at 6 (P <0.01), 12 (P <0.01) and 24 months (P <0.05), and a higher HAQ score (P <0.01) compared with YORA. At baseline and 24 months, LORA was more often associated with erosions (P <0.01 for both) and a higher Larsen score (P <0.001 for both). LORA was more often treated with corticosteroids (P <0.01), less often with methotrexate (P <0.001) and biologics (P <0.001). YORA was more often associated with early DMARD treatment (P <0.001). Multiple regression analyses supported our findings regarding impact of age on chosen treatment.
CONCLUSION: YORA patients were more frequently ACPA-positive. LORA was more often associated with erosions, higher Larsen scores, disease activity and HAQ at baseline. Nevertheless, YORA was treated earlier with DMARDs, whilst LORA was more often treated with corticosteroids and with less DMARDs in early disease. This could have implications for development of co-morbidities.
BioMed Central, 2014. Vol. 16, no 2, R94- p.