title: Sonography Is Superior to Serum-Based Biomarkers for Measuring Disease Status in Experimental Rheumatoid Arthritis.
abstract: OBJECTIVE
  Progress in developing novel rational treatments for rheumatoid arthritis (RA) critically depends on preclinical work in experimental animals. However, there is lack of insight into the most appropriate mode of noninvasive measurement of disease status in experimental RA. This study compared sonography with serum biomarkers in a rabbit model of RA.
  
  
  METHODS
  Six-month-old male New Zealand White rabbits were randomized into 2 groups: antigen-induced arthritis group (n = 25), which was subjected to ovalbumin immunization and intra-articular injection; and control group (n = 5). Pathologic changes in the knee joints were evaluated by sonography, and serum C-reactive protein, tumor necrosis factor TNF-α, and interleukin 1 were measured by enzyme-linked immunosorbent assay. Synovial pathologic scores were obtained by ultrasound-guided biopsy.
  
  
  RESULTS
  A total of 23 rabbits (2 rabbits died before the end of the study) in the antigen-induced arthritis group and 5 rabbits in the control group completed the study. Sonographic scores for all rabbits were graded from 0 to 3, according to grayscale sonography, synovitis, and blood flow. Synovial lesions were evident on sonography before week 4; however, serum biomarkers slowly increased until weeks 5 and 6 (P < .05). Although both sonography and serum biomarkers correlated significantly with synovitis scoring, the correlations for the sonographically derived parameters were better. The correlation indices between pathologic scores and synovial membranes thickness, blood flow, and resistive index were 0.798, 0.557, and -0.320, respectively, whereas the correlation indices between pathologic scores and tumor necrosis factor α, interleukin 1, and C-reactive protein levels were 0.451, 0.503, and 0.529.
  
  
  CONCLUSIONS
  Sonographic findings had better correlations with histologic scoring than serologic biomarkers of disease activity in the RA rabbit model, especially at early stages. Local pathologic assessment of disease status by sonography is possible.
authors: Ultrasound Department, First Affiliated Hospital of Fujian Medical University, Fuzhou, China.
authors: Shuqiang
authors: S
authors: Chen
authors: Rheumatology Department, Fujian Medical University, Fuzhou, China.
authors: Qing
authors: Q
authors: Zheng
authors: Ultrasound Department, First Affiliated Hospital of Fujian Medical University, Fuzhou, China.
authors: Hui
authors: H
authors: Liu
authors: Ultrasound Department, First Affiliated Hospital of Fujian Medical University, Fuzhou, China.
authors: Jinshu
authors: J
authors: Zeng
authors: Ultrasound Department, First Affiliated Hospital of Fujian Medical University, Fuzhou, China.
authors: Zhen
authors: Z
authors: Ye
authors: Ultrasound Department, First Affiliated Hospital of Xiamen University, Xiamen, China.
authors: Yiming
authors: Y
authors: Su
authors: Ultrasound Department, Second Affiliated Hospital of Fujian Medical University, Department of Clinical Medicine, Quanzhou Medical College, after University, Quanzhou, China lgr_feus@sina.com.
authors: Guorong
authors: G
authors: Lv
mesh_terms: D000818:Animals; D001172:Arthritis, Rheumatoid / Q000097:blood* / Q000000981:diagnostic imaging* / Q000473:pathology; D015415:Biomarkers / Q000097:blood; D001706:Biopsy; D002097:C-Reactive Protein; D004195:Disease Models, Animal; D004797:Enzyme-Linked Immunosorbent Assay; D007375:Interleukin-1 / Q000097:blood; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000473:pathology; D008297:Male; D011817:Rabbits; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D014409:Tumor Necrosis Factor-alpha / Q000097:blood; D014463:Ultrasonography
chemical_list: D015415:Biomarkers; D007375:Interleukin-1; D014409:Tumor Necrosis Factor-alpha; D002097:C-Reactive Protein
keywords: animal model; biopsy; musculoskeletal ultrasound; pathology; rheumatoid arthritis; sonography