Do new and old biomarkers of early undifferentiated arthritis correlate with Arthritis Impact Measurement Scales?

Abstract

In early undifferentiated arthritis (EUA), the relationship between inflammatory biomarkers and disability is still unclear. The aim of this study was to correlate inflammatory biomarkers with the Arthritis Impact Measurement Scales (AIMS) in EUA. Seventy patients with EUA were compared with 20 patients with established rheumatoid arthritis (RA). The association of AIMS [mobility, physical impairment (PI), dexterity, household activities, activities of daily living (ADL), social activity, pain, anxiety, depression] with serum laboratory [phase acute reactants, calprotectin, interleukin-6, tumour necrosis factor (TNF)-α, rheumatoid factor, anti-nuclear and anti-citrullinated peptide antibodies, HLA-DRB], clinical [Clinical Disease Activity Index (CDAI), fatigue, pain and stiffness NRS], x-ray and ultrasound biomarkers was analysed with non-parametric Spearman's rank correlation and Mann-Whitney U tests. No differences in AIMS were found between EUA and established RA patients, or between EUA patients that evolved into early RA (n=17) and those that remained EUA (n=53) at six months of follow-up. In EUA, erythrocyte sedimentation rate correlated with mobility impairment, PI and depression (p=0.04, p=0.03 and p=0.022, respectively), TNF-α correlated with PI (p=0.01) and calprotectin with anxiety (p=0.02). HLA-DRB1*11-positive EUA patients had lower ADL deficiency (p=0.006), depression (p=0.0004) and anxiety (p=0.01). CDAI correlated with PI (p=0.01) and pain (p=0.01), fatigue with PI (p=0.0001) and ADL (p=0.009), stiffness with PI (p=0.01), and Power Doppler ultrasound synovitis with PI (p=0.02) and pain (p=0.007). In EUA, physical and mood disorders are associated with new and old inflammatory serological, clinical and imaging biomarkers. HLA-DRB1*11-positivity may be protective against these disease-related features.