Background There is a short window of opportunity for early diagnosis and treatment of rheumatoid arthritis, that may be crucial for reaching remission and a low rate of radiographic progression. High resolution power doppler ultrasonography (PDUS) is helpful in early detection of synovitis and may help to select patients at higher risk of developing structural radiographic progression of joint damage.
Objectives To establish whether the presence of basal power doppler signal in patients with early arthritis may be helpful in order to establish the risk of radiographic progression at 12 months of follow-up.
Methods We studied the presence of ultrasonographic Power Doppler (PD) signal on 28 joints (shoulders, elbows, wrists, MCPs, knees) and 44 joints (28 joints and in addition hips, Tarsus, ankles and MTPs), with a mid-range equipment GE L5, in 70 patients with suspected early arthritis. The patients were included with at least one of the following inclusion criteria: a) Swelling in 2 or more joints b) pain in MCPs, MTPs and/or the wrists c) morning stiffness of more than 30 minutes with <12 months duration of the symptoms. Presence or not of basal high acute phase reactants (CPR>5 mg/dl; ESR >20 mmHg) and DAS28>5.1 for each patient were registered. In 62 patients completed hands and feet radiology were available both in basal and 12 months visits. Scores according Sharp/van der Heijde method (Sharp modified method) (1) were recorded for each patient. Clinical relevant Radiographic progression was defined for each patient as a stadistical significant difference between Sharp/van der Heijde method scores in basal and 12 months visits that exceeded the SDD (smallest detectable difference) obtained from the intraobserver variability study for radiographic assessment (SDD: Erosions 2,5; narrowing 2,71; Total 2,25). Statistical study: Chi-square, Fisher exact test, p univariant and Odds Ratio calculation, SDD.
Results The presence of basal power doppler signal in ≥1 joints of 44 (PD44) at baseline shows statistically significant association with radiographic progression of erosions and total progression (erosions plus narrowing) at 12 months p<0.005, OR 5,57 (1,56–19,79) and p=0.048, OR=3,42 (1,02–11,49) respectively, whereas the presence of at least one joint with power doppler signal of 28 joints (PD28) was only associated to total progression p=0.017, OR 4,23 (1,23–14.49). High acute phase basal reactants (CRP and ESR) were as well associated to progression of erosions, p=0.005 OR 4,80 (1,53–15,16) and p=0.025, OR 3,25 (1.14–9,28) respectively. A DAS28>5,1 at baseline was associated to radiographic progression of erosions (p=0.021), narrowing (p=0.005) and both (p=0.001).
Conclusions The presence of at least one joint with power doppler signal of 44 joints (PD44) at baseline may help to predict the progression of erosions at 12 months of follow up in patients with early RA. The presence of positive acute phase reactants (CRP,ESR) and DAS28 high activity (>5,1) in our study increased the risk of radiographic progression of erosions as well.
van der Heijde D. How to read Radiographs according to the Sharp/van der Heijde Method. The Journal of Rheumatology 1999;2:3743–745.
Disclosure of Interest None declared