Relation of some clinical composite indices of disease activity in rheumatoid arthritis to a simplified 12 joint power Doppler ultrasound activity index

Aim of the workTo assess the association of some clinical composite disease activity indices with a simplified 12 joint power Doppler ultrasound (PDUS) activity index in rheumatoid arthritis (RA).Patients and methodsOne hundred RA patients who fulfilled the 2010 European league against rheumatism/American college of Rheumatology (EULAR/ACR) classification criteria for RA were recruited from the Rheumatology outpatient clinic, Cairo University Hospitals. Disease activity score (DAS28), the simplified disease activity index (SDAI), clinical disease activity index (CDAI) as well as mean overall index for RA (MOI-RA) were assessed. Grey Scale Ultrasonography (GSUS) and PDUS activity assessment was performed using a simplified 12-joint score.ResultsThe 100 patients were 80 females and 20 males (F:M 4:1). Their mean age was 44.4 ± 10.8 years with disease duration of 6.3 ± 4.7 years. Rheumatoid factor was positive in 77 %. DAS28 was 4.5 ± 1.3, SDAI 27.7 ± 22.7, CDAI 17.5 ± 13.2 and MOI-RA 86.8 ± 25.1. On US, tenosynovitis was present in 10 %, irregularity in 23 % and erosion in 62 %. The mean 12-point PDUS was 3.53 ± 4.16 and the overall US score 10.34 ± 9.3. A significant correlation was found between the US findings of overall synovitis, degree of PD and US score with DAS28 (r = 0.3, p < 0.0001; r = 0.4, p < 0.0001 and r = 0.3, p < 0.0001) with SDAI (r = 0.3, p < 0.0001; r = 0.4,p < 0.0001; r = 0.4, p < 0.0001) and with MOI-RA score (r = 0.3, p < 0.0001; r = 0.4, p < 0.0001 and r = 0.4, p < 0.0001 respectively) but the highest correlations was with CDAI (r = 0.4, p < 0.0001; r = 0.5, p < 0.0001 and r = 0.4, p < 0.0001 respectively).ConclusionSimplified 12 -joint PDUS score is well correlated with activity indices in RA patients.