Ultrasonography with power Doppler may be more sensitive than a clinical examination in detecting synovitis among patients with inactive juvenile idiopathic arthritis, according to the results of a Spanish study presented at the annual European Congress of Rheumatology.
The technology could help physicians determine the best course of treatment for these patients.
Using ultrasonography in a group of children with clinically inactive juvenile idiopathic arthritis (JIA), Dr. Paz Collado of Severo Ochoa University Hospital in Madrid and her colleagues at five other hospitals found that 37 of 1,496 (2.5%) joints studied had gray-scale synovial hypertrophy. A total of 18 of the 37 (48%) presented with an increased power Doppler signal, representing synovial hyperemia, a sign of inflammation, said Dr. Collado, a pediatric rheumatologist.
Dr. Paz Collado
"The current clinical definition of inactive disease, now applied to patients with no clinical symptoms or signs of arthritis activity, could actually mean low disease activity with no functional impairment for some patients," she said in an interview. The technology could be useful in identifying disease persistence before discontinuing treatment but should be a complementary tool, she said. "Clinical history and imaging techniques should be used together to confirm or reject persistent inflammation that could lead to damage in JIA."
Ultrasonography also could be ideal for monitoring therapy, she said.
Dr. Collado and her colleagues studied the prevalence of abnormalities detected by ultrasonography in 34 children with JIA aged 4-16 years. Half of the study patients had attained one or more previous periods of disease inactivity. Twenty-three patients had attained clinical remission with disease-modifying antirheumatic drugs (DMARDs), and 11 patients did so off medication. Investigators performed clinical and ultrasonography assessments blindly on 44 joints in each patient, and used the OMERACT (Outcome Measure in Rheumatology in Clinical Trials) definitions for synovitis and tenosynovitis. They evaluated areas including the shoulder, elbow, wrist, hip, knee, ankle, midfoot, and hands. "Just the presence of a Doppler signal inside the intra-articular synovium or in the synovial sheath was considered as inflammatory activity for our study," the authors said.
The researchers found inflammation more often in some joints, such as knees, ankles, wrists, and the small joints of fingers. "Thirteen (38.2%) patients had evidence of at least one abnormal ultrasound finding; although the number of ultrasound abnormalities detected in patients who achieved remission on DMARDs was higher than in those who achieved remission off medication, there were no significant differences between the two groups in detecting gray-scale synovitis (P = .86), gray-scale tenosynovitis (P = .78), and power Doppler signal (P = .38)," the authors wrote.
"Our study shows that a proportion of patients presenting with clinically inactive disease had gray-scale synovitis, and some of them seem to have had inflammatory activity as detected by power Doppler," said the authors. "The significance of these findings has importance in order to obtain an accurate definition of disease status in the growing skeleton of JIA patients."
Researchers contributing to the study were from Ramón y Cajal University Hospital, La Paz University Hospital, Gregorio Marañón Hospital, and Niño Jesús Hospital, all in Madrid; and Valle de Hebrón University Hospital in Barcelona.
The study was funded by Pfizer. Dr. Collado and her coauthors disclosed receiving grant/research support from the company.