Application of MRI for Musculoskeletal Involvement in SLE

Overview

Articular involvement can reach up to 95% within the chronic multisystemic manifestations of SLE (1). Originally, a non-erosive pattern of articular inflammation was described, but the emergence of more sensitive imaging techniques, such as MRI (2, 3), show synovitis, erosions (hand: 47-48%, carpus 82-84% in SLE; and hand: 18%, carpus 97% in healthy individuals), bone oedema (hand: 4-5%, carpus 13-16% in SLE; and 0% in healthy individuals) and tenosynovitis (hand 47%, carpus 79%; not evaluated in healthy individuals) in patients with SLE (4, 5). Nowadays, a specific validated pattern of articular involvement associated with this disease does not yet exist, although it has begun to be studied. This research tries to evaluate the presence, frequency and distribution of inflammatory articular manifestations in SLE (erosions, bone oedema, synovitis or tenosynovitis) using MRI (6), with the objective of trying to establish a specific pattern for this disease, if it exists, that can shorten the diagnostic process. Moreover, it tries to characterise, if they exist, clinical differences between various patient groups according to their articular involvement.

BACKGROUND AND RATIONALE * Nowadays no valid classification system for SLE-related arthritis/tenosynovitis exists. * Data are not sufficient to establish an SLE-specific pattern of inflammatory involvement, similar to the pattern known for other inflammatory diseases such as rheumatoid arthritis (RA). * Erosive arthritis associated with SLE has been typically related to patients that meet the criteria both for SLE and RA - syndrome known as Rhupus; but only a few data exist that classify erosive involvement of articular inflammation of pure SLE. * No research exists that links the articular inflammatory pathology associated with SLE with its effect on quality of life (degree of fatigue and HAQ) or with the rest of manifestations and comorbidities associated with SLE. * Being able to predict the development of SLE-related arthritis/tenosynovitis would be very useful when it comes to establishing the clinical management, treatment and prognosis of patients with SLE. OBJECTIVES * GENERAL: \- To describe the kind of inflammatory articular involvement (synovitis/erosions/bone oedema/tenosynovitis) (6,7) and its frequency in patients affected by pure SLE (excluding Rhupus, mixed connective tissue disease, overlap syndromes). * SPECIFIC: * To propose, if possible, an SLE-specific typical pattern of articular involvement. * To establish clinical and serological differences (extra-articular manifestations, autoimmunity, treatment received, comorbidities and quality of life) according to the type of inflammatory articular involvement and in comparison to healthy individuals. * To evaluate the possible link between SLEDAI/SLICC scores and the involvement using MRI. HYPOTHESIS * Patients with SLE have a specific inflammatory articular disease. * A SLE-specific pattern of articular involvement exists. * There are clinical and serological differences depending on the different patterns of articular involvement in SLE.