Diagnostic potential of ultrasound in systemic lupus erythematosus patients with joint involvement: Relation to anticyclic citrullinated peptide (anti-CCP), disease activity and functional status

Detection of joint involvement in patients with systemic lupus erythematosus using musculoskeletal ultrasound and its correlation with disease activity

Background

Musculoskeletal symptoms are common and could be the first presenting symptom in up to 50% of systemic lupus erythematosus patients, and they affect more than 95% of patients during the clinical course. The present study aimed to assess joint involvement in the wrists, hands, and knees of SLE patients using musculoskeletal ultrasonography and to correlate these findings with disease activity.

The study enrolled 40 Patients with SLE who were attending the Immunology outpatient clinic and internal medicine department of Beni-Suef University Hospital and 20 age and sex nearly matched healthy controls who have no rheumatological complaints. Participants had a comprehensive physical examination, series of laboratory tests, functional assessment by Health Assessment Questionnaire score, disease activity assessment of by European Consensus Lupus Activity score, and radiological examination by high-resolution Ultrasound machine called (LOGIC P 9) using a gray-scale US mode (13–18 MHz) with Power Doppler to detect joint synovitis, synovial hypertrophy, bone erosions and or tenosynovitis.

Results

There was a statistically significant prevalence of US abnormality of knee joints in both asymptomatic and symptomatic cases versus controls contrary to the wrist and hand US abnormality. The presence of SLE increases the risk of US abnormalities in knee joints 28 times more than controls also increasing the age of the patient one year increase the probability of getting abnormal findings in the knee joint by 1.156 times. While the only independent variable that can affect US abnormal findings in the wrist joint is the increase in Systolic Blood Pressure 1 mmHg with 1.06 times.

Conclusion

Musculoskeletal Ultrasound with applied Power Doppler is a good tool for the detection of early affection of joints either in symptomatic or asymptomatic SLE patients.

An Overview of the Intrinsic Role of Citrullination in Autoimmune Disorders

A protein undergoes many types of posttranslation modification. Citrullination is one of these modifications, where an arginine amino acid is converted to a citrulline amino acid. This process depends on catalytic enzymes such as peptidylarginine deiminase enzymes (PADs). This modification leads to a charge shift, which affects the protein structure, protein-protein interactions, and hydrogen bond formation, and it may cause protein denaturation. The irreversible citrullination reaction is not limited to a specific protein, cell, or tissue. It can target a wide range of proteins in the cell membrane, cytoplasm, nucleus, and mitochondria. Citrullination is a normal reaction during cell death. Apoptosis is normally accompanied with a clearance process via scavenger cells. A defect in the clearance system either in terms of efficiency or capacity may occur due to massive cell death, which may result in the accumulation and leakage of PAD enzymes and the citrullinated peptide from the necrotized cell which could be recognized by the immune system, where the immunological tolerance will be avoided and the autoimmune disorders will be subsequently triggered. The induction of autoimmune responses, autoantibody production, and cytokines involved in the major autoimmune diseases will be discussed.

Musculoskeletal Ultrasound in Systemic Lupus Erythematosus: Systematic Literature Review by the Lupus Task Force of the OMERACT Ultrasound Working Group

OBJECTIVE

To identify and synthesize the best available evidence on the application of musculoskeletal (MSK) ultrasound (US) in patients with systemic lupus erythematosus (SLE) and to present the measurement properties of US in different elementary lesions and pathologies.

METHODS

A systematic literature search of PubMed, Embase, and the Cochrane Library was performed. Original articles were included that were published in English between August 1, 2014, and December 31, 2018, reporting US, Doppler, synovitis, joint effusion, bone erosion, tenosynovitis, and enthesitis in patients with SLE. Data extraction focused on the definition and quantification of US-detected synovitis, joint effusion, bone erosion, tenosynovitis, enthesitis, and the measurement properties of US according to the OMERACT Filter 2.1 instruments selection.

RESULTS

Of the 143 identified articles, 15 were included. Most articles were cross-sectional studies (14/15, 93%). The majority of the studies used the OMERACT definitions for ultrasonographic pathology. Regarding the measurement properties of US in different elementary lesions and pathologies, all studies dealt with face validity, content validity, and feasibility. Most studies achieved construct validity. Concerning the reliability of image reading, 1 study (1/15, 7%) assessed both intraobserver and interobserver reliability. For image acquisition, 4 studies (4/15, 27%) evaluated interobserver reliability and none had evaluated intraobserver reliability. Criterion validity was assessed in 1 study (1/15, 7%). Responsiveness was not considered in any of the studies.

CONCLUSION

This literature review demonstrates the need for further research and validation work to define the involvement of US as an outcome measurement instrument for the MSK manifestations in patients with SLE.