Background The presence of acute phase reactants high can assist in the diagnosis and classification of patients with rheumatoid arthritis, although on occasions in early arthritis may be within the range of normality.
Objectives The objective was to establish whether the presence of basal Doppler signal in patients with negative reactants may be helpful in order to establish the risk of final diagnosis of rheumatoid arthritis a year, following ACR criteria 1987
Methods We studied the presence of 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 patients with suspected early arthritis in which the ESR was normal according to two different criteria or the CRP was negative. The patients had 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 (*Criteria SERAP Study), with <12 months of evolution of the symptoms. None of the patients had a previous diagnosis of rheumatoid arthritis or other inflammatory joint disease nor had received prior treatment with steroids or DMARDs. It was considered normal CRP ≤5mg/L (normal range 0–5). It was considered normal ESR (mm/h) according to two criteria: a) ESR +1: ≤20 in all patients or (b) ESR +2 (criterion depending on the age and sex): Age ≥50 years is normal ≤20 in males and ≤30 in women; minors of 50 years is normal ≤15 mm/h in males and ≤20 in women (1). At one year follow-up was established whether patients met criteria for RA 1987 ACR.
Results In 35 patients with normal basal ESR, by criteria 2 (criterion by ESR age and sex), the presence of basal power doppler signal in ≥1 joints of 44 (PD44) in baseline visit shows statistically significant association with the RA diagnosis at 12 months by ACR 1987 classification criteria, with p=0.032, OR=6 (1,33–27,05). In 32 patients with normal basal ESR by criteria ESR 1 (<20 mm/h), the presence of basal power doppler signal in at least one joint of 44 (PD44 basal) shows statistically significant association with the diagnosis at year of AR, with p=0.030, OR=6 (1,25–28,84), not so PD28 (p=0.150). In 25 patients with basal negative CRP, the presence of at least one joint with power doppler signal (PD28 and PD44) are not associated in a statistically significant way with final diagnosis of RA at 12 months following ACR 1987 criteria (p=0.428 and p=0.226, respectively).
Conclusions The presence of at least one joint with power doppler signal of 44 joints (PD44) on baseline visit may help to predict the RA diagnosis at 12 months of follow up according to criteria ACR 1987, in patients with normal basal ESR. In patients with normal basal CRP, PD44 could not establish statistically significant differences for the diagnosis of AR a year according to criteria ACR 1987. In our study PD28 could not predict the RA diagnosis at 12 months by ACR 1987 criteria.
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Disclosure of Interest None declared