Antigen-induced arthritis in rabbits: a comparative study between high-resolution ultrasound and contrast-enhanced ultrasound and pathologic findings

Abstract

The objective of this study was to explore the feasibility and value of high-resolution ultrasound and contrast-enhanced ultrasound in evaluation of synovitis in rabbit knee joint in antigen-induced arthritis (AIA). Thirty-six rabbits were divided into three groups, each injected with different doses of ovalbumin (OVA) into the right knee joint. On week 1 and 4, 6 randomly selected in each group were killed. Each knee joint undergone the high-resolution ultrasound to measure capsule thickness and contrast-enhanced ultrasound to measure synovium thickness. The results from the ultrasound examinations were compared with those of pathologic examinations. Different OVA doses resulted in different modeling success rate, different pathological synovitis score, and different capsule and synovium thickness measured by ultrasound. The diagnostic accuracy of synovitis by ultrasound was high. The ultrasound measurement revealed that the capsule thickness on week 4 was lessened than that on week 1, while the synovial thickness on week 4 was greater than that on week 1. Both the joint capsule and synovium thickness measured by ultrasound were significantly and positively correlated to the pathologic synovitis score (P < 0.05). The synovial thickness on week 4 is more correlated to the synovitis score than the capsule thickness, rather than that on week 1. Injection of OVA of different doses results in different modeling success rate and synovitis severity. The high-resolution ultrasound and contrast-enhanced ultrasound can be used to determine whether the AIA was made successfully and evaluate the synovitis severity. In chronic inflammatory phase, the contrast-enhanced ultrasound has better effect.

Power Doppler Ultrasound Phenotyping of Expanding versus Collapsed Popliteal Lymph Nodes in Murine Inflammatory Arthritis

“…A scoring system based on gray scale and PD-US on knees and ankles in the collagen-induced arthritis (CIA) mouse model has been established with a strong correlation between histology and US score [33]. US has been used to evaluate synovitis in the antigen-induced arthritis (AIA) rabbit model to measure capsule thickness and CE-US to measure synovium thickness, which was found to significantly and positively correlate with the histological scoring of synovitis [35]. Both studies demonstrate the feasibility of US as an outcome measure of arthritis in small animals.…”

Value of Contrast-Enhanced Ultrasonography in Evaluating Rheumatoid Arthritis: Preliminary Research Based on an Animal Model

“…Rabbit antigen-induced arthritis model (AIA) is a large-animal model that has been developed over the past 30 years [ 21 ], especially in the research on imaging. Qiu [ 22 ] reported a nearly 100% success rate when 8 mg of Ova was injected into the joints. In fact, the size of the rabbit knee is comparable with that of human peripheral joints, which are the most common lesions in RA.…”

Sonography Is Superior to Serum‐Based Biomarkers for Measuring Disease Status in Experimental Rheumatoid Arthritis

“…The animals were submitted to AIA and were previously shown to mimic the important aspects of RA. [19][20][21] Previous research published by Qiu et al 22 showed a 100%…”

“…The animals were submitted to AIA and were previously shown to mimic the important aspects of RA 19–21. Previous research published by Qiu et al22 showed a 100% success rate in this model when 8 mg of ovalbumin was injected into the knee joint in the final stage of the model. Results of this study are consistent with those results and support the robustness of the AIA model.…”