OBJECTIVETo observe the differential effect of joint ultrasound on the syndrome differentiation of rheumatoid arthritis (RA) by observing the high frequency ultrasound performances among inactive stage and different syndromes in active stage.

METHODSTotally 83 RA patients in the active stage were assigned to the dampness heat syndrome group (DHS, 59 cases)and the cold dampness syndrome group (CDS, 24 cases) according to Chinese medicine (CM) syndrome typing. Besides, 20 RA patients in the remission stage were recruited as the control group (abbreviated as the remission group). By using high frequency ultrasound and power Doppler ultrasound technology, a comparative observation of synovitis, tenosynovitis, synovial blood flow, and bone erosion in the 2nd-5th metacarpophalangeal (MCP) joints, proximal interphalangeal (PIP) joints, wrist joints, knee joints, the second and the fifth metatarsophalangeal (MTP) joints (a total of 24 joints) was performed in all patients. Correlation analyses were performed between the ultrasound performance, laboratory indices, and the disease activity. Ultrasound data of each RA patient were analyzed by their total scores. Χ2 test was used for enumeration data. The measurement data was expressed as x ± s. One-way ANOVA was used for data of normal distribution, while non- parametric test was used for data of non-normal distribution. Correlation analysis of two variables was performed for clinical indicators and ultrasound indicators. Its significance was detected using Pearson correlation.

RESULTSCompared with the remission group, the severity degree of synovitis, tenosynovitis, synovial blood flow, and bone erosion significantly increased in the DHS group (P < 0.01). There was statistical difference in ESR, CRP, anti-CCP, DAS28 score, and the positive rate of RF (P < 0.05, P < 0.01). There was statistical difference in the severity degree of synovitis and synovial blood flow, and DAS28 score in the CDS group (P < 0.05). Compared with the CDS group, there was statistical difference in the four ultrasound indices (P < 0.05, P < 0.01), ESR, CRP, anti-CCP, DAS28 score, and the positive rate of RF in the DHS group (P < 0.05, P < 0.01). There was no statistical difference in G, IgG, IgA, or IgM among the three groups (P > 0.05). There existed positive correlation between ESR and the synovitis degree, synovial blood flow, and bone erosion in the DHS group (r = 0.444, 0.397, 0.486, P < 0.05).There existed positive correlation between ESR and the synovitis degree, bone erosion, and synovial blood flow in the DHS group (r = 0.378, 0.270, P < 0.05). There existed positive correlation between the DAS28 score and the synovitis degree and synovial blood flow in the DHS group (r = 0.304, 0.351, P < 0.05).

CONCLUSIONSThe inflammation degree was the most severe in RA patients of DHS. High frequency ultrasound could provide better evidence for Chinese medical syndrome differentiation of RA patients.