Ultrasound helpful in early detection of Rheumatoid Arthritis
Ultrasonographic imaging of patients who present with arthralgia may be useful for identifying which patients are not likely to go on to have inflammatory arthritis, new study shows.
Patients at risk for RA need to be identified as early as possible, preferably when no clinically apparent synovitis can be detected. Up to now, it has been fairly difficult to identify those patients with arthralgia who develop inflammatory arthritis (IA), but recent studies using ultrasound (US) suggest that earlier detection is possible. The researchers aimed to identify patients with arthralgia developing IA within 1 year using US to detect subclinical synovitis at first consultation.This will lead to early initiation of effective disease-modifying antirheumatic drugs (DMARDs) and slowing disease progression and diminishing joint damage, the authors noted. Therefore, starting DMARDs in the arthralgia phase, or even sooner, could lead to better patient outcomes.
This was a multicenter prospective cohort study in which 159 patients with inflammatory joint complaints of the hands, feet, or shoulders that could not be explained by other conditions were monitored for 1 year. Patients had to have at least two painful joints and two of the following criteria adapted from the Rotterdam Early Arthritis Cohort (REACH) trial:
- Morning stiffness for more than 1 hour
- Inability to clench a fist in the morning
- Pain when shaking someone's hand
- Pins and needles in the fingers
- Difficulties wearing rings or shoes
- Family history of rheumatoid arthritis
- Unexplained fatigue for less than a year
In a multi-centre cohort study, we followed patients with arthralgia with at least two painful joints of the hands, feet or shoulders without clinical synovitis over 1 year. Symptom duration was < 1 year, and symptoms were not explained by other conditions. At baseline and at 6 and 12 months, data were collected for physical examinations, laboratory values and diagnoses. At baseline, we examined 26 joints ultrasonographically (bilateral metacarpophalangeal joints 2–5, proximal interphalangeal joints 2–5, wrist and metatarsophalangeal joints 2–5). Scoring was done semi-quantitatively on greyscale (GS; 0–3) and power Doppler (PD; 0–3) images. US synovitis was defined as GS ≥ 2 and/or PD ≥ 1. IA was defined as clinical soft tissue swelling. Sensitivity and specificity were used to assess the diagnostic value of US for the development of IA. Univariate logistic regression was used to analyse the association between independent variables and the incidence of IA. For multivariate logistic regression, the strongest variables (p < 0.157) were selected. Missing values for independent variables were imputed.
It was found that in a total of 196 patients were included, and 159 completed 12 months of follow-up. Thirty-one (16%) patients developed IA, of whom 59% showed US synovitis at baseline. The sensitivity and specificity of US synovitis were 59% and 68%, respectively. If no joints were positive on US, negative predictive value was 89%. In the multivariate logistic regression, age (OR 1.1), the presence of morning stiffness for > 30 minutes (OR 3.3) and PD signal (OR 3.4) were associated with incident IA.
Following are the major findings:
- Within 1 year of follow-up, inflammatory arthritis had developed in 31 patients (16%), of whom 59% showed ultrasound synovitis at baseline
- Ultrasound did not perform well in ruling in inflammatory arthritis, with a positive predictive value of only 26%
- Ultrasound did perform well in ruling out inflammatory arthritis in patients who did not have ultrasound synovitis, with a negative predictive value of 89%
- Positive power Doppler signal, morning stiffness, and age were independently associated with the development of inflammatory arthritis after 1 year
It was therefore concluded that the presence of PD signal, morning stiffness for > 30 minutes and age at baseline were independently associated with the development of IA. Regarding the value of US in the diagnostic workup of patients with early arthralgia at risk for IA, US did perform well in ruling out IA in patients who did not have US synovitis. Ultrasound has been shown to be able to detect synovitis before its clinical appearance, the researchers noted. "Given the high [negative predictive value], ultrasound has added value to identify which patients would not develop inflammatory arthritis."
For more details click on the following link: https://link.springer.com/article/10.1186/s13075-017-1405-y