PET assessment of disease activity in children with juvenile idiopathic arthritis.
BACKGROUND
The degree of 18-fluorodeoxyglucose (FDG) uptake is previously reported to correlate with physical examination and laboratory tests for evaluating disease activity in patients with rheumatoid arthritis. The clinical validity of (18)F-FDG positron emission tomography (PET) has not been evaluated in juvenile idiopathic arthritis (JIA).


OBJECTIVE
To assess the relationship between (18)F-FDG PET uptake and disease activity in children with JIA.


METHODS
A total of 560 joints in 28 children (mean age, 5.4 years; range, 1-16 years) with JIA who had undergone whole-body (18)F-FDG PET before treatment were retrospectively assessed clinically, biochemically and radiographically. PET images were assessed independently by two readers. We investigated the relationships between the degree of synovial (18)F-FDG uptake and radiographic and clinical symptoms and laboratory findings.


RESULTS
Joint tenderness and swelling had a positive association with abnormal (18)F-FDG uptake in the joint [odds ratio (OR) 5.37, 7.12, respectively]. The standardized uptake value (SUV) max correlated with the neutrophil count, plasma C-reactive protein (CRP), erythrocyte sedimentation rate (ESR) and matrix metalloproteinase (MMP) 3. Joint erosion (OR, 6.17), soft-tissue swelling (OR, 3.77), major joints involvement (OR, 3.50), tenderness (OR, 5.22), and CRP concentration in plasma (OR, 1.81) were positively associated with SUVmax.


CONCLUSIONS
The degree of (18)F-FDG uptake may be associated with the severity of synovitis in children with JIA.
Department of Radiology, Yokohama City University Graduate School of Medicine, 3-9, Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan. utateish@yokohama-cu.ac.jp
Ukihide
U
Tateishi
Tomoyuki
T
Imagawa
Noriko
N
Kanezawa
Tetsuhiko
T
Okabe
Kazuya
K
Shizukuishi
Tomio
T
Inoue
Shumpei
S
Yokota
D000293:Adolescent; D001171:Arthritis, Juvenile / Q000000981:diagnostic imaging*; D002648:Child; D002675:Child, Preschool; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007223:Infant; D008297:Male; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013583:Synovial Membrane / Q000000981:diagnostic imaging*
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18