Longitudinal power Doppler ultrasonographic assessment of joint inflammatory activity in early rheumatoid arthritis: predictive value in disease activity and radiologic progression.
OBJECTIVE
To evaluate the sensitivity to change of power Doppler ultrasound (PDUS) assessment of joint inflammation and the predictive value of PDUS parameters in disease activity and radiologic outcome in patients with early rheumatoid arthritis (RA).


METHODS
Forty-two patients with early RA who started therapy with disease-modifying antirheumatic drugs underwent blinded sequential clinical, laboratory, and ultrasound assessment at baseline, 3 months, 6 months, and 1 year and radiographic assessment at baseline and 1 year. For each patient, 28-joint Disease Activity Score (DAS28) was recorded at each visit. The presence of synovitis was investigated in 28 joints using gray-scale ultrasonography and intraarticular power Doppler signal. Active synovitis was defined as intraarticular synovitis detected with power Doppler signal. The ultrasound joint count for active synovitis and an overall joint index for power Doppler signal were calculated. Sensitivity to change of PDUS variables was assessed by estimating the smallest detectable difference (SDD) from the intraobserver variability.


RESULTS
The SDD for ultrasound joint count for active synovitis and ultrasound joint index for power Doppler signal was lower than mean changes from baseline to 3 months, 6 months, and 1 year. Time-integrated values of PDUS parameters demonstrated a highly significant correlation with DAS28 after 1 year (r = 0.63, P < 0.001) and a stronger correlation with radiographic progression (r = 0.59-0.66, P < 0.001) than clinical and laboratory parameters (r < 0.5).


CONCLUSIONS
PDUS is a sensitive and reliable method for longitudinal assessment of inflammatory activity in early RA. PDUS findings may have a predictive value in disease activity and radiographic outcome.
Naredo
Esperanza
E
Hospital Severo Ochoa, Madrid, Spain. esnaredo@eresmas.com
Collado
Paz
P
Cruz
Ana
A
Palop
Mercedes J
MJ
Cabero
Félix
F
Richi
Patricia
P
Carmona
Loreto
L
Crespo
Manuel
M
D000208:Acute Disease; D000328:Adult; D000368:Aged; D018501:Antirheumatic Agents / Q000627:therapeutic use; D001172:Arthritis, Rheumatoid / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000503:physiopathology; D001175:Arthrography / Q000379:methods; D018450:Disease Progression; D005260:Female; D006801:Humans; D007596:Joints / Q000000981:diagnostic imaging* / Q000503:physiopathology; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013585:Synovitis / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000503:physiopathology; D018608:Ultrasonography, Doppler / Q000379:methods*
D018501:Antirheumatic Agents