The Value Of High-frequency Ultrasonography In Diagnosis And Therapy Of Rheumatoid Arthritis

Objective Early diagnosis and early therapy improves outcomes in rheumatoid arthritis (RA). High-frequency ultrasonography (HFUS) technique is a sensitive tool for use in the assessment of synovitis and bone erosion in joints, which can evaluate joint inflammation, bone destruction and disease activity accurately and objectively. The objective of the study was to determine the value of this technique in assisting early diagnosis of patients with RA and estimating the effect of drug therapy.Methods105patients with clinically apparent synovitis of at least one joint and inflammatory joint symptoms of6months or less duration underwent baseline clinical, laboratory and imaging assessments. Among the105patients,58adults with RA diagnosed according to the revised1987criteria of the American College of Rheumatology (ACR) were recruited into the RA subjects. RA subjects were assigned to3different cohorts according to their baseline28-joint count disease activity scores (DAS28) and their respective treatment program as follows:low disease activity RA (2.6<DAS28<3.2) and no requirement for corticosteroid and biological agent treatment (n=16); moderate/high disease activity RA (DAS28>3.2) and no requirement for corticosteroid and biological agent treatment (n=22); and subjucts meriting in corticosteroid or biological agent treatment with any disease activity (n=20), then were followed respectively for3months, evaluating the condition of disease renewedly at Week2(Ml), Month1(M2), Month2(M3),Month3(M4) after treatment, comparing the changes of clinical indexes, inflammatory markers and HFUS indexes, determining the effect of this indexes in evaluating disease activity and the effect of drug therapy. The other47undifferentiated arthritis (UA) adults who didn’t fulfil the revised1987criteria of the ACR and2010criteria of the ACR/EULAR were followed for12months, evaluating the condition of disease renewedly after3months (M1),6months (M2) and12Months to determine outcome by2010ACR/EULAR criteria and confirm the final diagnosis.Results (1) In all the105patients, ultrasonography detected more synovitis than clinical examination at the joint level. In early RA patients, ultrasonography is able to detect more subclinical synovitis in the wrist and metacarpophalangeal joint. (2) Among the HFUS indexes of synovitis, power doppler signal has better sensitivity than synovial thickness in the presentation of synovitis, part of the proximal interphalangeal joints which didn’t detected synovial thickness also found the existence of abnormal power doppler signal.(3) The result of the58diagnosed RA adults evaluating disease activity and the effect of drug therapy by clinical or ultraphonic ways and serum inflammatory markers, indicated that synovial thickness and power doppler signal indices were closely correlated with baseline DAS28scores. In terms of observed treatment effect, there were no significant changes throughout the time-course in DAS28, ESR, CRP and synovial thickness indices in all the3groups; whereas, in the moderate/high disease activity group and received corticosteroid or biological agent treatment group there were a significant progressive decrease in the power doppler signal index after2weeks.(4)47undifferentiated arthritis adults were followed1year,19patients developed RA (VERA) by2010criteria, in which7patients fulfil the1987criteria. If adding ultrasound variables to the1987criteria and new2010criteria, the19VERA patients baseline classified8and15RA respectively.(5) There were no significant difference in power doppler signal index and bone erosion joints between the seropositive RA and seronegative RA patients in our study.Conclusion (1) At the joint level, ultrasonography detected more synovitis than clinical examination, while, HFUS has better sensitivity than clinical evaluation for the detection of more subclinical synovitis in the wrist and metacarpophalangeal joint.(2) In all the HFUS indexes of detected synovitis, power doppler signal may be more sensitive than synovial thickness in the presentation of synovitis.(3) Adding ultrasound to clinical variables in the1987ACR criteria and2010ACR/EULAR criteria classified more patients as RA, whereas, the detection of subclinical disease by HFUS increased diagnosed sensitivity at a cost of specificity resulting in a drop. So combining with the history, clinical features, and other laboratory examination indexes comprehensive analysis to establish the diagnosis is very important.(4) Subjects with RA with varying disease activity could be differentiated on the basis of synovial thickness and power doppler signal findings, baseline indices of synovial thickness and power doppler signal were related to DAS28. There were more variation in baseline indices of synovial thickness and power doppler signal for the RA groups than for the OA group. Power doppler signal is more rapid and sensitive than DAS28, ESR, CRP and synovial thickness indices in the terms of observed treatment effect. The study indicates that PDUS has the potential to serve as a pharmacodynamic marker of synovial inflammation. It may also have the benefit of early identification of individual response to therapeutic change.(5) There were no significant difference in power doppler signal index and bone erosion joints between the seropositive RA and seronegative RA patients in our study, the result indicate that both of the pathogenesis may obviously different.