Monitoring total-body inflammation and damage in joints and entheses: the first follow-up study of whole-body magnetic resonance imaging in rheumatoid arthritis.

OBJECTIVE: To investigate changes in whole-body magnetic resonance imaging (WBMRI) inflammatory and structural lesions in most joints and entheses in patients with rheumatoid arthritis (RA) treated with adalimumab. METHODS: WBMRI was obtained at weeks 0, 6, 16, and 52 in a 52 week follow-up study of 37 RA patients starting treatment with adalimumab. Readability and reliability of WBMRI were investigated for 76 peripheral joints, 23 discovertebral units, the sacroiliac joints, and 33 entheses. Changes in WBMRI joint and entheses counts were investigated. RESULTS: The readability of peripheral and axial joints was 82-100%, being less for elbows and small joints of the feet. For entheses, 72-100% were readable, except for entheses at the anterior chest wall, elbow, knee, and plantar fascia. The intrareader agreement was high for bone marrow oedema (BMO), bone erosion (80-100%), and enthesitis (77-100%), and slightly lower for synovitis and soft tissue inflammation (50-100%). All synovitis, BMO, and soft tissue inflammation counts decreased numerically during treatment. The 26-joint synovitis WBMRI count decreased significantly during the first 16 weeks for patients with a good European League Against Rheumatism (EULAR) response (from median 6 to 4, p < 0.05), but not for patients with a moderate or no EULAR response. There were no overall changes in structural lesions. CONCLUSIONS: WBMRI allows simultaneous monitoring of most axial and peripheral joints and entheses in RA patients and can visualize a decrease in inflammatory counts during treatment. This first WBMRI follow-up study of patients with RA encourages further investigation of the usefulness of WBMRI in RA.

Pattern of bone erosion and bone proliferation in psoriatic arthritis hands: a high-resolution computed tomography and radiography follow-up study during adalimumab therapy.

OBJECTIVES: To investigate the pattern and development of bone erosion and proliferation in patients with psoriatic arthritis (PsA) during treatment with adalimumab, using high-resolution computed tomography (CT) and conventional radiography. METHOD: Forty-one biologic-naïve PsA patients were initiated with adalimumab 40 mg subcutaneously every other week. CT and radiography of the 2nd-5th metacarpophalangeal (MCP), proximal interphalangeal (PIP), and distal interphalangeal (DIP) joints were conducted at baseline (n = 41) and after 24 weeks (n = 32). Changes in bone erosion and proliferation are described and the imaging modalities compared. RESULTS: Ninety percent of bone erosions detected by CT were located in the metacarpal heads, and most frequently in the 2nd-3rd MCP joints. Radial (37%) and ulnar (31%) surfaces were more frequently eroded than dorsal (10%) and palmar (22%) sites. Using CT, bone proliferations were located primarily on the sides of the distal part of the DIP joints (43% of all proliferations), but also proximally in DIP (17%) and MCP joints (27%). For bone erosions and proliferations, respectively, radiography showed a low sensitivity (17% and 26%), but a high specificity (98% and 95%) and accuracy (93% and 87%), with CT as the gold standard reference. Neither CT nor radiography revealed statistically significant changes in bone erosion or proliferation scores between baseline and follow-up. CONCLUSIONS: Patterns of bone erosion and proliferation in PsA hands were revealed in more detail by CT than by radiography. No overall progression or repair could be detected during adalimumab treatment with either of the methods.

Reliability and responsiveness of dynamic contrast-enhanced magnetic resonance imaging in rheumatoid arthritis.

OBJECTIVES: To investigate the responsiveness to treatment and the reliability of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in rheumatoid arthritis (RA) knee joints. METHODS: DCE-MRI was performed in 12 clinically active RA knee joints before and 1, 7, 30, and 180 days after intra-articular injection with 80 mg methylprednisolone. Using semi-automated image processing software, DCE-MRI parameters, including the initial rate of enhancement (IRE) and maximal enhancement (ME), were generated for three regions of interest (ROIs): 'Whole slice', 'Quick ROI', and 'Precise ROI'. The smallest detectable difference (SDD), the smallest detectable change (SDC), and intra- and inter-reader intraclass correlation coefficients (ICCs) were used to assess the reliability of DCE-MRI. Responsiveness to treatment was assessed by the standardized response mean (SRM). RESULTS: In all patients clinical remission of the knee was achieved at day 7. All DCE-MRI parameters decreased from day 0 to day 7. Using the Quick and Precise ROI methods, respectively, IRE decreased by 63% and 69%, ME decreased by 11% and 11%, N decreased by 55% and 57%, and IRE × N decreased by 84% and 85%. The intra- and inter-reader ICCs were very high (0.96-1.00). The decrease in DCE-MRI parameters was larger than the SDC for all patients. SRM was large for all parameters, ranging from -1.04 to -2.40. When the Whole slice ROI method was used, no parameters were responsive to treatment. CONCLUSIONS: DCE-MRI analysed using semi-automatic software is a reliable and responsive tool for assessing treatment in RA knees joints. Rough manual delineation of the joint to omit enhancement artefacts is necessary.

Plasma YKL-40: a potential biomarker for psoriatic arthritis?

BACKGROUND: Plasma YKL-40 is an inflammatory biomarker. No useful biomarker exists in patients with psoriasis or psoriatic arthritis. OBJECTIVE: To measure YKL-40 and high-sensitivity C-reactive protein (hs-CRP) in patients with psoriasis or psoriatic arthritis before and during treatment. METHODS: In 48 patients with psoriasis, we measured YKL-40, hs-CRP and Psoriasis Area and Severity Index (PASI) at inclusion and in a subgroup of 14 patients, we repeated the measurements after four to six weeks of methotrexate treatment. In 42 patients with psoriatic arthritis, we measured YKL-40 and hs-CRP at inclusion and during 48 weeks of adalimumab treatment. The patients with psoriatic arthritis were divided into responders and non-responders. RESULTS: In patients with psoriasis, the baseline median PASI score was 10.8 and baseline YKL-40 was 45 µg/L. Seventeen per cent had elevated plasma YKL-40 compared with healthy subjects. Baseline PASI and YKL-40 were not correlated (rho = 0.14, P = 0.347) and YKL-40 and hs-CRP remained unchanged after treatment. In patients with psoriatic arthritis, the median pretreatment YKL-40 was 112 µg/L and 43% had elevated YKL-40. YKL-40 decreased in 33 patients who responded to adalimumab (from 112 µg/L to 68 at 48 weeks, P = 0.007). Hs-CRP decreased (from 4.65 mg/L to 0.91, P = 0.013) in the responders. In the non-responders (n = 9), YKL-40 and hs-CRP remained unchanged. CONCLUSIONS: YKL-40 is elevated in many patients with psoriatic arthritis, but not in patients with psoriasis. YKL-40 decreased in patients with psoriatic arthritis who responded to treatment. YKL-40 may be a useful biomarker to monitor the effect of treatment with tumour necrosis factor-α inhibitors in patients with psoriatic arthritis.

Dynamic gadolinium-enhanced magnetic resonance imaging allows accurate assessment of the synovial inflammatory activity in rheumatoid arthritis knee joints: a comparison with synovial histology.

OBJECTIVE: To determine whether dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) evaluated using semi-automatic image processing software can accurately assess synovial inflammation in rheumatoid arthritis (RA) knee joints. METHODS: In 17 RA patients undergoing knee surgery, the average grade of histological synovial inflammation was determined from four biopsies obtained during surgery. A preoperative series of T(1)-weighted dynamic fast low-angle shot (FLASH) MR images was obtained. Parameters characterizing contrast uptake dynamics, including the initial rate of enhancement (IRE), were generated by the software in three different areas: (I) the entire slice (Whole slice); (II) a manually outlined region of interest (ROI) drawn quickly around the joint, omitting large artefacts such as blood vessels (Quick ROI); and (III) a manually outlined ROI following the synovial capsule of the knee joint (Precise ROI). Intra- and inter-reader agreement was assessed using the intra-class correlation coefficient (ICC). RESULTS: The IRE from the Quick ROI and the Precise ROI revealed high correlations to the grade of histological inflammation (Spearman's correlation coefficient (rho) = 0.70, p = 0.001 and rho = 0.74, p = 0.001, respectively). Intra- and inter-reader ICCs were very high (0.93-1.00). No Whole slice parameters were correlated to histology. CONCLUSION: DCE-MRI provides fast and accurate assessment of synovial inflammation in RA patients. Manual outlining of the joint to omit large artefacts is necessary.