Comparison of Role of Hand and Wrist Ultrasound in Diagnosis of Subclinical Synovitis in Patients with Systemic Lupus Erythematosus and Rheumatoid Arthritis: A Retrospective, Single-Center Study

Ability of the European League Against Rheumatism-Outcomes Measures in Rheumatology combined scoring system for grading dorsal joint space synovitis to accurately evaluate ultrasound-detected hand synovitis

Background

The European League Against Rheumatism-Outcomes Measures in Rheumatology (EULAR-OMERACT) recommend only scanning dorsal spaces for scoring ultrasound-detected hand synovitis. This study evaluated the efficiency of the combined scoring system only depending on dorsal joint spaces synovitis in diagnosing and evaluating ultrasound-detected hand synovitis.

Methods

The data of 56 patients who underwent hand joint ultrasonography exams in the Ultrasound Department of West China Hospital, Sichuan University were prospectively collected. The participants formed a random series. The images of each patient included gray-scale (GS) and power Doppler (PD) images of bilateral first to fifth metacarpophalangeal joints (MCP) and the thumb and second to fifth proximal interphalangeal joints (IP). The synovial thickness was measured quantitatively in GS images, and the synovial GS scores in the dorsal joint spaces and PD scores in the dorsal and volar joint spaces were calculated according to the combined EULAR-OMERACT scoring system.

Results

The detection rate of synovitis in the first to fifth MCP, thumb and second to fifth proximal IP synovitis were 41.4% (232/560) and 33.9% (190/560), respectively. The sensitivity of only inspecting the dorsal joint spaces with GS ultrasound was 79.3% for MCP and 52.6% for the thumb and second to fifth proximal IPs. The PD scores were higher in the dorsal joint spaces than in the volar joint spaces (P value <0.001). The combined scores were higher than either the GS or PD scores alone in the dorsal joint spaces (P value of the combined scores vs. GS scores =0.001; P value of the combined scores vs. PD scores <0.001).

Conclusions

Adopting the EULAR-OMERACT combined scoring standard is recommended to evaluate ultrasound-detected hand synovitis, as determined by the highest value of the GS scores or the PD scores. More specifically, PD scores can mainly be used to appraise the dorsal joint spaces. However, GS scores should be used to evaluate both the dorsal joint spaces and the volar joint spaces.

Update on Current Imaging of Systemic Lupus Erythematous in Adults and Juveniles

Systemic lupus erythematosus (SLE) is an autoimmune disease involving multiple organs and organ systems. Musculoskeletal (MSK) involvement is one of the most frequent and the earliest locations of disease. This disease affects joints and periarticular soft tissues, tendon sheaths and tendons, bones, and muscles. Multimodality imaging, including radiography, ultrasound (US), and magnetic resonance imaging (MRI), plays a significant role in the initial evaluation and treatment follow up of MSK manifestations of the SLE. In this paper, we illustrate MSK imaging features in three clinical forms of SLE, including nondeforming nonerosive arthritis, deforming nonerosive arthropathy, and erosive arthropathy, as well as the other complications and features of SLE within the MSK system in adults and juveniles. Advances in imaging are included. Conventional radiography primarily shows late skeletal lesions, whereas the US and MRI are valuable in the diagnosis of the early inflammatory changes of the soft tissues and bone marrow, as well as late skeletal manifestations. In nondeforming nonerosive arthritis, US and MRI show effusions, synovial and/or tenosynovial hypertrophy, and vascularity, whereas radiographs are normal. Deforming arthritis clinically resembles that observed in rheumatoid arthritis, but it is reversible, and US and MRI show features of inflammation of periarticular soft tissues (capsule, ligaments, and tendons) without the pannus and destruction classically observed in RA. Erosions are rarely seen, and this form of disease is called rhupus syndrome.

Erosive arthritis in systemic lupus erythematosus: not only Rhupus

Systemic lupus erythematosus (SLE)-related arthritis has been traditionally defined as non-erosive and is therefore considered a minor manifestation requiring a mild treatment. However, the concept of non-erosive arthritis in SLE has been challenged with the advent of sensitive imaging techniques, such as high-resolution ultrasound with power Doppler or magnetic resonance. The application of these new imaging tools has demonstrated that up to 40% of SLE patients with joint involvement can develop erosive damage. Thus, this more aggressive phenotype can be identified not only in patients overlapping with rheumatoid arthritis (RA). This issue has been considered for the first time in the classification criteria proposed by Systemic Lupus International Collaborating Clinics in 2012, in which the old definition of "non-erosive arthritis" was replaced with either synovitis or tenderness in two or more joints with morning stiffness, suggesting the possible presence of an erosive phenotype. Accordingly, the 2019 EULAR/ACR's SLE recommendations advise treatment with immunosuppressant or biological drugs for patients with RA-like moderate arthritis. As a result, several studies have investigated the presence of biomarkers associated with SLE erosive damage. A relevant role seems to be played by the autoantibodies directed against post-translational modified proteins: above all, a significant association has been observed with antibodies directed against citrullinated and carbamylated proteins. Conversely, the rheumatoid factor was not associated with this more aggressive SLE-related arthritis. Nonetheless, some pro-inflammatory factors have been associated with erosive damage in SLE patients. These results suggest new pathogenic mechanisms underlining erosive arthritis, only partially shared with RA. Hence, in the present narrative review, we summarized available data about erosive arthritis in SLE patients, in the light of its impact on therapeutic decisions.