Is ultrasound a better target than clinical disease activity scores in rheumatoid arthritis with fibromyalgia? A case-control study.
OBJECTIVE
Our goal is to study the correlations among gray-scale seven-joint ultrasound score (GS-US7), power Doppler seven-joint ultrasound score (PD-US7), disease activity score-28 joints (DAS28), simplified disease activity index (SDAI) and clinical disease activity index (CDAI) in patients with and without fibromyalgia (FM).


METHODS
A matched case-control study included all patients consecutively seen in the Rheumatoid Arthritis (RA) Clinic. Participants were allocated into one of two groups: RA with FM and RA without FM. Ultrasound (US) and clinical scoring were blinded for the presence of FM. Medians and proportions were compared by Mann-Whitney's test and McNemar's test, respectively. Spearman's rank correlation coefficients (rs) were calculated among clinical and US scores and differences were tested by r-to-z transformation test.


RESULTS
Seventy-two women were included, out of 247 RA patients, mostly white, with median (IQR) age of 57.5 (49.3-66.8) years, with RA symptoms for 13.0 (6.0-19.0) years and FM symptoms for 6.0 (2.0-15.0) years. Disease-modifying antirheumatic drugs, non-steroidal anti-inflammatory drugs and prednisone use was comparable between groups. Objective activity parameters were not different between groups. RA patients with FM had greater DAS28, SDAI and CDAI but similar GS-US7 and PD-US7. GS-US7 correlated with DAS28, SDAI and CDAI in patients with and without FM (rs = 0.36-0.57), while PD-US7 correlated with clinical scores only in patients without FM (rs = 0.35-0.38).


CONCLUSIONS
To our knowledge, this is the first study to demonstrate that ultrasound synovitis scores are not affected by FM in RA patients. PD-US7 performed better than GS-US7 in long-standing RA patients with DAS28, SDAI or CDAI allegedly overestimated due to FM. Since sonographic synovitis predicts erosion better than swollen joint count, C-reactive protein and erythrocyte sedimentation rate, US should be considered a promising treatment target in RA patients with FM.
Hospital de Clínicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
Rafael Mendonça
RM
da Silva Chakr
Hospital de Clínicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
João Carlos Tavares
JC
Brenol
Hospital de Clínicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
Marina
M
Behar
Pontifícia Universidade Católica de Campinas, Campinas, São Paulo, Brazil.
José Alexandre
JA
Mendonça
Hospital de Clínicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
Charles Lubianca
CL
Kohem
Hospital de Clínicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
Odirlei André
OA
Monticielo
Hospital de Clínicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
Claiton Viegas
CV
Brenol
Hospital de Clínicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
Ricardo Machado
RM
Xavier
D000368:Aged; D001172:Arthritis, Rheumatoid / Q000150:complications* / Q000000981:diagnostic imaging* / Q000628:therapy; D016022:Case-Control Studies; D005260:Female; D005356:Fibromyalgia / Q000150:complications*; D006801:Humans; D007596:Joints / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D008875:Middle Aged; D014463:Ultrasonography