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Abstract Rheumatoid arthritis (RA) is a common autoimmune disease leading to severe disability and premature mortality with incidence ranging from 5 to 50 per 100 000 adults in developed countries. Accurate assessment of disease activity and joint damage in RA is important for monitoring treatment efficiency and for prediction of the outcome of the disease. Management of RA and the determination of treatment decisions depend largely on the level of disease activity. There is no single gold standard for quantifying the level of disease activity. In clinical practice, a number of parameters (such as clinical assessment of tender and swollen joints, a global assessment of disease activity, and either an ESR or CRP level) are used to determine the level of RA disease activity. A number of validated instruments for RA in the form of composite indices that combine these parameters into a score are used in clinical practice, including disease activity score (DAS28), simplified disease activity index (SDAI) and ACR remission criteria. They allowed us to quantify the level of disease activity at any given point in time. Within the last decade, musculoskeletal ultrasonography has played an increasingly important role in the evaluation and monitoring of patients with chronic inflammatory arthritis. US can readily evaluate synovitis, a pathological hallmark of RA at both the anatomic and vascular levels. It also can detect the presence of bony erosion which is a cardinal finding in RA joints as a result of pathological destructive changes. Power Doppler US has the ability to identify the presence of vascularization that is associated with the presence of inflammation. MRI has undoubtedly enhanced the understanding of the pathophysiology of inflammatory changes in RA. It allows a three- dimensional precise assessment of the bony and surrounding soft tissue structures within a targeted joint. The main ‘activity’ findings detected by MRI include synovitis, tenosynovitis and BME while the ‘damage’ findings include bony erosions and JSN. MRI also avoids ionizing radiation and the images obtained can be stored and read centrally, which is useful for multi-centre clinical trials. The aim of this work was to evaluate patients with rheumatoid arthritis in activity and remission; clinically using DAS 28 score with other activity scores and objectively using high resolution ultrasonography, power Doppler ultrasono-graphy and magnetic resonance imaging, to document clinical findings and to identify the most sensitive objective method to be used in assessing activity and remission for patients follow up. This study was conducted on 50 RA patients and 10 healthy controls, the patients were recruited from the Physical medicine, Rehabilitation and Rheumatology out-patient clinic of Ain Shams University hospitals. All candidates underwent history talking and relevant clinical, laboratory and radiological testing to confirm or exclude the diagnosis and identify the degree of disease activity and extent of joints affection. All candidates underwent full medical history taking and thorough clinical examination with special emphasis on articular examination and laboratory investigation. All patients underwent assessment of degree of disease activity using modified DAS28 score, modified ACR criteria for remission and simplified disease activity index (SDAI). Patients were divided according to their DAS28 activity score into four groups, remission, low disease activity, moderate disease activity and high disease activity. Functional assessment of the patients was done using modified health assessment questionnaire and assessment of hand functions using Duruoz’s hand index. Radiological assessment was done by using plain X-ray of both hands where the images were scored by the modified Genant scoring system. US examination was done for the clinically more affected hand (or the dominant hand in healthy subjects) of each candidate including grayscale and Doppler imaging of 12 joint areas including 4 areas of wrist joint (radio-carpal, ulnar-carpal, distal radioulnar, and intercarpal compartments), 2nd through 5th MCP and 2nd through 5th PIP joints. A total of 600 joints were examined for the presence of synovitis, erosions and presence of power doppler activity. Scoring of the findings was done by the 0 to 3 semi-quantitative score described by Szkudlarek and his colleges in 2003. MRI examination was done for the same hand including same 12 joint area scanned by US. A total of 600 joints were examined for the presence of synovitis, BME and erosions. Scoring of the findings was done by the 0 to 3 semi-quantitative score described OMERACAT RA MRI (RAMRIS) scoring system (Ǿstergaard et al., 2003). Statistical correlations were done between some of the clinical, laboratory and radiological data of various study groups and also the results obtained from different activity scores. Also statistical correlations were done between the results achieved by US and MRI and their scores, their ability to detected inflammatory changes occurring in active joints, and also in detection of destructive bony changes. The present study revealed: • DAS28 score could not be dependable alone as an indication of the degree of disease activity in RA patients especially when we want to identify those in remission. • ACR criteria for remission and SDAI were stricter than DAS28 in identifying patients in remission. • Number of joints showing synovitis by GSUS and their score was significantly different among different groups according to the degree of activity, with a high statistically significant positive correlation to the DAS28 score in both parameters. • Number of joints showing increased vascularity by power doppler US and their score was significantly high among the high activity group, with a statistically significant positive correlation to the DAS28 score in both parameters. • The US examination showed a higher percentage of joints to be inflamed when compared to those that were clinically revealed by clinical examination where 39% was affected by US while only 23% was affected clinically. • Number of joints showing bony erosions by GSUS and their score was significantly high among the high disease activity group, with a statistically significant positive correlation to the DAS28 score and the number of erosions, but the correlation was not significant with the erosion scores. • Number of joints showing synovitis by MRI and their score was significantly different among different groups according to the degree of activity, with a high statistically significant positive correlation to the DAS28 score in both parameters. • Number of joints showing BME or erosions by MRI and their score was not significantly different among different activity groups. The correlation of BME and erosions, either their count or score, was not statistically significant to the DAS28 score of the patients. • Only 6% of the patients who were in remission according to DAS28 score, ACR remission criteria and SDAI score and also they had no evidence of synovitis or joint inflammation that could be detected by US or MRI examination. • Most of the patients (85%) showing remission according to DAS28 activity score showed inflammatory signs in at least one of their examined joints evident by either US alone or combined with PD or by MRI or even both techniques • US was able to accurately detect inflammation in affected joints more than those that were detected by MRI (39% and 29% respectively of the total number of joints examined) and more than the number of total affected joints clinically (23%). Also in 64% of patients US detected synovitis in number of joints more than that detected by MRI. • Both radiological techniques had high ability to detect inflamed joints with close agreement but favoring the US especially when adding the value of the power doppler activity for better visualization of the inflammation where the scores of the joints with synovitis revealed by US was significantly higher than the scores of synovitis shown by MRI. • MRI was able to accurately detect bone destructive changes in affected joints more than those that were detected by US (34% and 26.8% respectively of the total number of joints examined) and more than the number of total affected joints by conventional radiographs (19%). Also in 60% of patients MRI detected erosions in number of joints more than that detected by US. • MRI was the most accurate and sensitive device for detecting bone erosion compared to other methods, also the scores of the joints with erosions revealed by MRI was significantly higher than the scores of erosions shown by US. • Our study supported the use of sensitive imaging techniques for the accurate evaluation of disease activity and the prediction of outcome in patients with RA, even when the findings of standard clinical measures of inflammatory activity have returned to normal. An objective imaging assessment improves the sensitivity of inflammation detection and a more accurate definition of the remission state. |