The role of ultrasound in assessing musculoskeletal symptoms of systemic lupus erythematosus: a systematic literature review

Microplastics Exposure Aggravates Synovitis and Pyroptosis in SLE by Activating NF-κB and NRF2/KEAP1 Signaling

Microplastics (MPs) represent an emerging pollutant capable of entering the human body through the respiratory and digestive systems, thereby posing significant health risks. Systemic lupus erythematosus (SLE) is a complex autoimmune disease that affects multiple organ systems, often presenting with polyarticular joint manifestations. Despite its relevance, there is currently limited research on the impact of MPs on lupus arthritis. This study aims to investigate the effects of MPs on joint inflammation in SLE. MRL/lpr mice exhibit SLE similar to that of humans. We administered either 0.5 mg/kg or 5 mg/kg of MPs to 8-week-old female MRL/lpr mice via oral ingestion. Our findings indicate that exposure to MPs can lead to synovial damage, adversely affecting the morphology and function of the knee joint, along with increased oxidative stress, apoptosis, synovial fibrosis, and the secretion of inflammatory cytokines. Notably, MPs significantly enhanced synovial cell pyroptosis by upregulating the expression of NLRP3, CASPASE-1, GSDMD, IL-1β, and IL-18. Mechanistic analyses further demonstrated that MPs exposure activates the NF-κB and NRF2/KEAP1 signaling pathways. Overall, our in vivo findings suggest that MPs exposure promotes synovial cell pyroptosis through increased oxidative stress and NF-κB signaling, thereby disrupting the structure and function of synovial tissue. This research provides new insights into the synovial damage associated with MPs exposure.

The burden of entheseal involvement in systemic lupus erythematosus: a comparative ultrasonograghic study

BACKGROUND

Imaging is crucial for identifying and diagnosis of the musculoskeletal (MSK) symptoms, which are one of the most typical manifestations of systemic lupus erythematosus (SLE). For the joints, tendons, and entheseal sites, ultrasonography has shown to be sensitive and accurate for the diagnosis of both inflammation and structural damage.

AIM

The goal of the current investigation is to determine the prevalence and the distribution of entheseal abnormalities in SLE patients, using musculoskeletal ultrasonography (MSUS) and to assess the relationship between entheseal sonographic changes and the SLE disease activity.

PATIENTS AND METHODS

One hundred sixty-eight subjects were studied (56 SLE patients, 56 psoriatic arthritis (PSA) patients, and 56 normal cases). To compare the frequency and the distribution of entheseal involvement, high-resolution MSUS was conducted to assess the entheseal sites of all patients in accordance with the Madrid Sonographic Enthesitis Index (MASEI).

RESULTS

Clinical enthesitis was detected in 39.3% of the SLE patients using the Leeds Enthesitis Index compared to 71% detected via US examination, indicating a high proportion of subclinical enthesitis in our SLE patients. The most frequently affected enthesis was the distal insertion of the patellar tendon at the tibial tuberosity which was detected in 41% of SLE patients. Enthesitis was significantly more frequent in PSA patients (100%) compared to SLE patients (71.4%) (p < 0.05) and more significantly frequent in SLE patients compared to the healthy controls (19.6%). There was a significant correlation between MASI and SLEDAI scores (r = 0.250*, p = 0.048) and the total protein in 24 h (r = 0.289*, p = 0.031). In addition, there was an inverse significant correlation between MASEI and serum albumin (r =  - 0.324*, p = 0.015).

CONCLUSION

In SLE patients, enthesitis is frequently clinical and ultrasound-verified. The most impacted enthesis is at the insertion of the quadriceps tendon. Enthesitis presence and the rise in the MASI score can serve as indicators of the severity of the SLE disease. Key Points • The most impacted entheseal site lies at the insertion of the quadriceps tendon. • The presence and the rise in MASEI score can serve as indicators of the severity of the SLE disease.

Musculoskeletal manifestations of systemic lupus erythematosus

MSK is the most common and impactful symptom of lupus at a population level. It has a variety of different presentations, but joint swelling is often not present despite imaging-proven synovitis. Imaging with US and MRI has been shown to improve detection of inflammation and identify treatment-responsive patients. In contrast, the SLEDAI shows poor sensitivity, specificity, and responsiveness. While BILAG and SLE-DAS are superior, they are still less accurate than imaging. These issues may explain why the evidence for conventional and biologic therapies for MSK lupus is complex. In clinical practice, physicians must take care not to underestimate MSK inflammation and consider using imaging. Future research should investigate new therapeutic targets specifically for synovitis and more sensitive outcome measures and trials to evaluate them.

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.

The Pathogenesis, Molecular Mechanisms, and Therapeutic Potential of the Interferon Pathway in Systemic Lupus Erythematosus and Other Autoimmune Diseases

Therapeutic success in treating patients with systemic lupus erythematosus (SLE) is limited by the multivariate disease etiology, multi-organ presentation, systemic involvement, and complex immunopathogenesis. Agents targeting B-cell differentiation and survival are not efficacious for all patients, indicating a need to target other inflammatory mediators. One such target is the type I interferon pathway. Type I interferons upregulate interferon gene signatures and mediate critical antiviral responses. Dysregulated type I interferon signaling is detectable in many patients with SLE and other autoimmune diseases, and the extent of this dysregulation is associated with disease severity, making type I interferons therapeutically tangible targets. The recent approval of the type I interferon-blocking antibody, anifrolumab, by the US Food and Drug Administration for the treatment of patients with SLE demonstrates the value of targeting this pathway. Nevertheless, the interferon pathway has pleiotropic biology, with multiple cellular targets and signaling components that are incompletely understood. Deconvoluting the complexity of the type I interferon pathway and its intersection with lupus disease pathology will be valuable for further development of targeted SLE therapeutics. This review summarizes the immune mediators of the interferon pathway, its association with disease pathogenesis, and therapeutic modalities targeting the dysregulated interferon pathway.

Evaluation of SLE arthritis using frequency domain optical imaging

OBJECTIVES

Systemic lupus erythematosus (SLE) affects the joints in up to 95% of patients. The diagnosis and evaluation of SLE arthritis remain challenging in both practice and clinical trials. Frequency domain optical imaging (FDOI) has been previously used to assess joint involvement in inflammatory arthritis. The objective of this study was to evaluate FDOI in SLE arthritis.

METHODS

Ninety-six proximal interphalangeal (PIP) joints from 16 patients with SLE arthritis and 60 PIP joints from 10 age-matched, gender-matched and race/ethnicity-matched controls were examined. A laser beam with a wavelength of 670 nm, 1 mm in diameter and intensity modulated at 300 MHz and 600 MHz was directed onto the dorsal surface of each joint, scanning across a sagittal plane. The transmitted light intensities and phase shifts were measured with an intensified charge-coupled device camera. The data were analysed using Discriminant Analysis and Support Vector Machine algorithms.

RESULTS

The amplitude and phase of the transmitted light were significantly different between SLE and control PIPs (p<0.05). Receiver operating characteristic (ROC) analysis of cross-validated models showed an Area Under the ROC Curve (AUC)of 0.89 with corresponding sensitivity of 95%, specificity of 79%, and accuracy of 80%.

CONCLUSION

This study is the first evaluation of optical methods in the assessment of SLE arthritis; there was a statistically significant difference in the FDOI signals between patients with SLE and healthy volunteers. The results show that FDOI may have the potential to provide an objective, user-independent, evaluation of SLE PIP joints arthritis.

Imaging of Joint and Soft Tissue Involvement in Systemic Lupus Erythematosus

PURPOSE OF REVIEW

To highlight the potential uses and applications of imaging in the assessment of the most common and relevant musculoskeletal (MSK) manifestations in systemic lupus erythematosus (SLE).

RECENT FINDINGS

Ultrasound (US) and magnetic resonance imaging (MRI) are accurate and sensitive in the assessment of inflammation and structural damage at the joint and soft tissue structures in patients with SLE. The US is particularly helpful for the detection of joint and/or tendon inflammation in patients with arthralgia but without clinical synovitis, and for the early identification of bone erosions. MRI plays a key role in the early diagnosis of osteonecrosis and in the assessment of muscle involvement (i.e., myositis and myopathy). Conventional radiography (CR) remains the traditional gold standard for the evaluation of structural damage in patients with joint involvement, and for the study of bone pathology. The diagnostic value of CR is affected by the poor sensitivity in demonstrating early structural changes at joint and soft tissue level. Computed tomography allows a detailed evaluation of bone damage. However, the inability to distinguish different soft tissues and the need for ionizing radiation limit its use to selected clinical circumstances. Nuclear imaging techniques are valuable resources in patients with suspected bone infection (i.e., osteomyelitis), especially when MRI is contraindicated. Finally, dual energy X-ray absorptiometry represents the imaging mainstay for the assessment and monitoring of bone status in patients with or at-risk of osteoporosis. Imaging provides relevant and valuable information in the assessment of MSK involvement in SLE.

Involvement of the wrist and hand joints and tendons in an Egyptian systemic lupus erythematosus cohort

Background

Systemic lupus erythematosus (SLE) patients often suffer hand function limitations even in the absence of symptoms related to joint or tendon disorders. Recent researches reported the presence of ultrasonographic (US) subclinical synovitis and tendon involvement in asymptomatic patients. We aimed to assess US patterns in SLE patients and determine their relationship with clinical assessment, disease activity and hand functional status using handheld dynamometry.

Results

We assessed 30 SLE patients (60 hands) using US; 21 (70%) patient had synovial hypertrophy, 8 (26%) showed a power Doppler (PD) activity, 6 (20%) had erosions and 11 (36.6%) had tendon US abnormality. Both patients with hand arthralgia/arthritis (symptomatic) and patients without arthralgia/arthritis (asymptomatic) had a statistically insignificant difference regarding the global synovitis score (p= 0.2) and disease activity (p= 0.3). However, the symptomatic group had a significantly increased number of joints with effusion (p= 0.04) and tendons involved (p= 0.04). The mean grip strength had a significant negative correlation with SLEDAI-2 K score (rs = − 0.4,p= 0.02) in the total patient group. In the asymptomatic group, a negative correlation was found between both mean grip (rs = − 0.5,p= 0.04) and pinch strength (rs = − 0.6,p= 0.01) with PD index, and mean pinch strength with the Jaccoud’s arthropathy index (rs = − 0.49,p= 0.05).

Conclusions

SLE patients may have higher subclinical synovitis, erosions and tendon involvement than expected, which may in turn reduce hand grip and pinch strength. Disease activity may also have a negative impact on the hand grip functional strength.

[Musculoskeletal ultrasound findings of symptomatic joints in patients with systemic lupus erythematosus]

OBJECTIVE

To investigate the types and distribution of musculoskeletal ultrasonographic changes of the symptomatic joints, their correlations with clinical manifestations in systemic lupus erythematosus (SLE) patients, as well as the differences of ultrasonographic changes from Rhupus syndrome [SLE overlapping with rheumatoid arthritis (RA)] patients.

METHODS

In the study, 114 SLE patients who complained of arthralgia or arthritis from May 2014 to August 2017 and 15 Rhupus syndrome patients were recruited for ultrasound evaluation. Ultrasound scans of the symptomatic joint areas were completed. The correlation between ultrasonographic changes and clinical characteristics was analyzed. Additionally, ultrasound changes of bilateral wrists and hands of the SLE patients were compared with those of the Rhupus syndrome patients.

RESULTS

In a total of the 114 SLE patients with 1 866 joints scanned, synovial hyperplasia, tenosynovitis, erosion, and osteophytes were all observed. Synovial hyperplasia was more often observed in wrists in 33.3% (23/69) patients, knees in 28.6% (12/42) patients, and ankles in 25.0% (7/28) patients. Tenosynovitis and erosion were most commonly found in shoulders in 35.0% (7/20) and 65.0% (13/20) patients. Osteophytes were more common in proximal interphalangeal (PIP) joints, elbows and knees. Among 69 patients with 22 joints (bilateral wrists and hands) scanned, 57 (82.6%) of them had ultrasonographic changes. Synovial hyperplasia was observed in 36.2% of the patients and erosion in 14.5% of the patients. The agreement between synovial hyperplasia and swollen joints in PIP was fair (κ=0.633, P<0.01), however poor in wrists between synovial hyperplasia and swollen/tender joints (κ=0.089, P=0.584). 18.4% patients with synovial hyperplasia had no tenderness or swollen clinically, while 15.8% patients with tenderness or swollen had no synovial hyperplasia on ultrasound. No correlation was found between ultrasonographic changes with the SLE disease activity index. Both synovial hyperplasia and erosion were more common in the Rhupus syndrome patients (73.3% vs. 36.2%, P=0.08; 66.7% vs. 14.5%, P=0.03) with significantly higher grey scale scores (7.4±6.4 vs. 1.6±4.1, P=0.04) than in the SLE patients.

CONCLUSION

Variety of changes could be observed by ultrasound in different joint areas of SLE patients. The ultrasonographic changes and clinical manifestations did not always correspond to each other. Synovial hyperplasia and erosion was more common in Rhupus syndrome patients.

Current status and recent advances on the use of ultrasonography in pediatric rheumatic diseases

BACKGROUND

Ultrasonography has become a useful tool in the clinical rheumatology settings in the last two decades, but its use has only recently been explored by pediatric rheumatologists. The aim of this article is to review the literature on the current status and recent advances on the use of ultrasound in pediatric rheumatic diseases.

DATA SOURCES

We have retrieved and reviewed the relevant articles from MEDLINE/PubMed databases published so far, on the applications of ultrasound in juvenile idiopathic arthritis (JIA), systemic lupus erythematosus, dermatomyositis, enthesitis, Sjogren's syndrome, and other rheumatic diseases. In addition, articles on novel ultrasound imaging technology of potential use in pediatric rheumatology are also reviewed.

RESULTS

In JIA, ultrasound can be used to detect subclinical synovitis, to improve the classification of patients in JIA subtypes, to capture early articular damage, to monitor treatment response, and to guide intraarticular injections. Ultrasound is also considered useful in other rheumatic disorders for the evaluation of musculoskeletal symptoms, assessment of parotid gland pathology, and measurement of skin thickness and pathology. Novel ultrasound techniques developed to augment the functionality of ultrasonography may also be applicable in pediatric rheumatic disorders.

CONCLUSIONS

Ultrasound shows great promise in the assessment and management of children with rheumatologic disorders. However, standardization and validation of ultrasound in healthy children and in patients with rheumatic diseases are still needed.

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.

Autoimmune Connective Tissue Diseases and the Risk of Rotator Cuff Repair Surgery: A Population-Based Retrospective Cohort Study

OBJECTIVES

Autoimmune connective tissue diseases (ACTDs) commonly involve the shoulder joint; however, clinical epidemiological studies investigating their association with tendons are scant. Rotator cuff (RC) tears can cause shoulder disability, and surgical intervention is usually required. The study investigated RC repair surgery risk in ACTD patients. The effect of anti-inflammatory medication on RC repair surgery risk was also investigated.

METHODS

We conducted a retrospective cohort study with a 7-year longitudinal follow-up period. Patients with systemic lupus erythematosus, systemic sclerosis, sicca syndrome, dermatomyositis and polymyositis diagnoses between 2004 and 2008 were enrolled. The control cohort comprised age- and sex-matched controls. The HR and adjusted HR (aHR) were estimated for the risk of RC surgery between ACTD and control cohorts after adjustment for confounders. Furthermore, the effects of steroid and non-steroidal anti-inflammatory drug (NSAID) use on the HR and aHR of RC surgery risk were analysed.

RESULTS

We enrolled 5019 ACTD patients and 25 095 controls in the ACTD and control cohorts, respectively. RC surgery incidence was 49 and 24 per 100 000 person-years in the ACTD and control cohorts, respectively. In the ACTD cohort, the crude HR for RC surgery was 2.08 (95% CI , 1.08 to 4.02, p<0.05), and the aHR was 1.97 (95% CI, 1.01 to 3.82, p<0.05). The ACTD patients who used NSAIDs had an aHR of 3.13 (95% CI, 1.21 to 8.07, p<0.05) compared with the controls, but the ACTD patients who used steroids did not have a significantly higher aHR than the controls.

CONCLUSIONS

ACTD patients had an increased risk of RC repair surgery. However, no difference was found in RC surgery risk when steroids were used compared with the control cohort. This could indicate that inflammation control may be a strategy for managing subsequent RC lesions.

Responsiveness of clinical and ultrasound outcome measures in musculoskeletal systemic lupus erythematosus

OBJECTIVE

To assess the responsiveness of clinical outcome measures in musculoskeletal SLE compared with US.

METHODS

A prospective pilot study was conducted in consecutive SLE patients with inflammatory musculoskeletal symptoms. Clinical assessments including SLEDAI, BILAG, 28 tender and swollen joint counts, physician and patient visual analogue scales (VAS), and US were performed at 0, 2 and 4 weeks following 120 mg i.m. methylprednisolone acetate. Responsiveness was analysed using changes and effect sizes using Cohen's criteria.

RESULTS

Twenty patients were recruited. Fifteen out of 20 had clinical swelling at baseline. All clinical and US parameters were significantly improved at week 4 (all P ⩽ 0.01). Musculoskeletal-BILAG score improved in 16/20. Musculoskeletal-SLEDAI improved in 7/20. SLE responder index 4 criteria were assessed in 19 patients with SLEDAI ⩾4 at baseline and were met in 9/19 at 4 weeks. Effect sizes at 4 weeks were large (>0.5) for US, physician VAS and BILAG, and medium (>0.3) for joint counts and SLEDAI. Large effect sizes for improvement in US grey-scale and power Doppler were observed in both SLE responder index 4 responders (r = -0.51 and -0.56, respectively) and non-responders (r = -0.62 and -0.59, respectively) at 4 weeks.

CONCLUSION

This is the first study to measure the responsiveness of clinical outcome measures in musculoskeletal SLE against an objective inflammation measure. BILAG and physician VAS were the most responsive clinical instruments. US was highly responsive in musculoskeletal SLE, while SLEDAI and joint counts appeared suboptimal for detection of improvement. These results suggest that clinical trials based on the SLEDAI and SLE responder index 4 may underestimate the efficacy of therapy in SLE.

Prediction of autoimmune connective tissue disease in an at-risk cohort: prognostic value of a novel two-score system for interferon status

OBJECTIVE

To evaluate clinical, interferon and imaging predictors of progression from 'At Risk' to autoimmune connective tissue diseases (AI-CTDs).

METHODS

A prospective observational study was conducted in At-Risk of AI-CTD (defined as antinuclear antibody (ANA) positive; ≤1 clinical systemic lupus erythematosus (SLE) criterion; symptom duration <12 months and treatment-naïve). Bloods and skin biopsy (non-lesional) were analysed for two interferon-stimulated gene expression scores previously described (IFN-Score-A and IFN-Score-B). Forty-nine healthy controls (HCs) and 114 SLE were used as negative and positive controls. Musculoskeletal ultrasound was performed. Progression was defined by meeting classification criteria for AI-CTDs at 12 months.

RESULTS

118 individuals with 12-month follow-up were included. Of these, 19/118 (16%) progressed to AI-CTD (SLE=14, primary Sjogren's=5). At baseline, both IFN scores differed among At-Risk, HCs and SLE groups (p<0.001) and both were elevated in At-Risk who progressed to AI-CTD at 12 months versus non-progressors, to a greater extent for IFN-Score-B (fold difference (95% CI) 3.22 (1.74 to 5.95), p<0.001) than IFN-Score-A (2.94 (1.14 to 7.54); p=0.018). Progressors did not have significantly greater baseline clinical characteristics or ultrasound findings. Fold difference between At-Risk and HCs for IFN-Score-A was markedly greater in skin than blood. In multivariable logistic regression, only family history of autoimmune rheumatic disease, OR 8.2 (95% CI 1.58 to 42.53) and IFN-Score-B, 3.79 (1.50-9.58) increased the odds of progression.

CONCLUSION

A two-factor interferon score and family history predict progression from ANA positivity to AI-CTD. These interferon scores may allow stratification of individuals At-Risk of AI-CTD permitting early intervention for disease prevention and avoid irreversible organ damage.

Musculoskeletal involvement and ultrasonography update in systemic lupus erythematosus: New insights and review

Ultrasonography has been rarely used to measure musculoskeletal and joint activity in systemic lupus erythematosus (SLE). The aim of this review is to discuss the utility and reliability of this non-invasive diagnostic tool for the assessment of joint disease in SLE patients. In the last decade, several reports have highlighted the role of ultrasonography for a better evaluation of SLE-related musculoskeletal symptoms. The symptoms have also been associated with worse outcomes in SLE; therefore, it is essential to seek useful and accessible techniques for better understanding of such patients who are insufficiently assessed by standard physical examination.

Categorisation of foot complaints in systemic lupus erythematosus (SLE) from a New Zealand cohort

Background

Foot complaints have been shown to be common in systemic lupus erythematosus (SLE) and heterogeneous in nature. We aimed to categorize self-reported foot complaints in people with SLE and foot symptoms.

Methods

A self-administered validated questionnaire was posted to 406 people with SLE attending adult rheumatology clinics across three health boards in Auckland, New Zealand. In addition to foot pain, vascular complaints, dermatological lesions and neurological symptoms were included in the analysis. Pairwise correlations among the variables were undertaken followed by factor analysis to identify and categorise associations between reported foot complaints.

Results

From the questionnaires returned, 93 full datasets were analysed. Participants’ were predominantly female (n = 87, 93.7%), with mean (SD) age of 50.4 (14.3) years and a mean (SD) disease duration of 13.1 (11) years. Three categories of foot complaint were determined: ‘foot pain’, ‘skin disorders’ and ‘vascular insufficiency’. These three groups provided the best fit (0.91) to describe the wide range of foot complaints reported by those with SLE. Factor analysis for foot pain demonstrated a high positive loading for the inter-correlation of foot pain in past month (0.83), foot pain today (0.71), intermittent claudication (0.71), numbness (0.62), loss of balance (0.81), swelling (0.59), foot joint pain (0.77), arch pain (0.68) and tendon pain (0.77). Skin disorders demonstrated a very high positive loading for 3 factors skin rash (0.82), blistering skin rash (0.95) and foot ulceration (0.88). In vascular insufficiency a high positive loading for cold feet (0.83), chilblains (0.76) and Raynaud’s phenomenon (0.70).

Conclusions

This work suggests people with SLE report three independent categories of foot complaints; foot pain, skin disorders or vascular insufficiency.

Electronic supplementary material

The online version of this article (doi:10.1186/s13047-017-0217-2) contains supplementary material, which is available to authorized users.

Ultrasound detects subclinical joint inflammation in the hands and wrists of patients with systemic lupus erythematosus without musculoskeletal symptoms

Objectives

To assess the prevalence and severity of ultrasonographic abnormalities of the hand and wrist of asymptomatic patients with systemic lupus erythematosus (SLE) and compare these findings with those from patients with SLE with musculoskeletal signs or symptoms and healthy controls.

Methods

We conducted a prospective cross-sectional study that evaluated bilaterally, with grey-scale and power Doppler (PD) ultrasound (US), the dorsal hand (2nd to 5th metacarpophalangeal and 2nd to 5th proximal interphalangeal joints) and wrist (radiocarpal, ulnocarpal and intercarpal joints) of 30 asymptomatic patients with SLE, 6 symptomatic patients with SLE and 10 controls. Synovial hypertrophy (SH) and intra-articular PD signal were scored using semiquantitative grading scales (0–3). Individual scores were graded as normal (SH≤1 and PD=0) or abnormal (SH≥2 or PD≥1). Global indexes for SH and PD were also calculated. US findings were correlated with clinical and laboratory data and disease activity indexes.

Results

US detected SH (score ≥1) in 77% asymptomatic patients with SLE, mostly graded as minimal (score 1: 63%). 23% of the asymptomatic patients with SLE showed abnormal US PD findings (SH≥2 or PD≥1). SH was present in all symptomatic patients with SLE, mostly graded as moderate (grade 2: 67%), and with associated PD signal (83%). SH (score 1) was identified in 50% of controls, however, none presented abnormal US PD findings. SH index in the asymptomatic SLE group was higher than in the control group (2.0 (0–5) vs 0.5 (0–2), median (range), p=0.01) and lower than in the symptomatic SLE group (7.0 (4–23), median (range), p<0.001). No significant correlation was demonstrated between US PD findings and clinical or laboratory variables and disease activity indexes.

Conclusion

A small subgroup of asymptomatic patients with SLE may present subclinical joint inflammation. Global US scores and PD signal may be important in disease evaluation and therapeutic monitoring.

Antibodies against carbamylated proteins and cyclic citrullinated peptides in systemic lupus erythematosus: results from two well-defined European cohorts

BACKGROUND

Articular manifestations are common in systemic lupus erythematosus (SLE) whereas erosive disease is not. Antibodies to cyclic citrullinated peptide (anti-CCP) are citrulline-dependent in rheumatoid arthritis (RA), whereas the opposite is suggested in SLE, as reactivity with cyclic arginine peptide (CAP) is typically present. Antibodies targeting carbamylated proteins (anti-CarP) may occur in anti-CCP/rheumatoid factor (RF)-negative cases long before clinical onset of RA. We analysed these antibody specificities in sera from European patients with SLE in relation to phenotypes, smoking habits and imaging data.

METHODS

Cases of SLE (n = 441) from Linköping, Sweden, and Leiden, the Netherlands, were classified according to American College of Rheumatology (ACR) and/or Systemic Lupus Erythematosus International Collaborating Clinics (SLICC) criteria. IgG anti-CCP, anti-CAP and anti-CarP were analysed by immunoassays. Radiographic data from 102 Swedish patients were available.

RESULTS

There were 16 Linköping (6.8%) and 11 Leiden patients (5.4%) who were anti-CCP-positive, of whom approximately one third were citrulline-dependent: 40/441 (9.1%) were anti-CarP-positive, and 33% of the anti-CarP-positive patients were identified as anti-CCP-positive. No associations were found comparing anti-CCP or anti-CarP with ACR-defined phenotypes, immunologic abnormalities or smoking habits. Radiographically confirmed erosions were found in 10 patients, and were significantly associated with anti-CCP, anti-CarP and RF. Musculoskeletal ultrasonography scores were higher in anti-CCP-positive compared to anti-CCP-negative patients.

CONCLUSIONS

In the hitherto largest anti-CarP study in SLE, we demonstrate that anti-CarP is more prevalent than anti-CCP and that the overlap is limited. We obtained some evidence that both autoantibodies seem to be associated with erosivity. Similar pathogenetic mechanisms to those seen in RA may be relevant in a subgroup of SLE cases with a phenotype dominated by arthritis.

Ultrasonographic assessment of bone erosions in the different subtypes of systemic lupus erythematosus arthritis: comparison with computed tomography

BACKGROUND

The aim was to determine the accuracy of high-resolution ultrasonography (US) for detecting erosion in the metacarpophalangeal (MCP) and wrist joints of patients with different subtypes of systemic lupus erythematosus (SLE) arthritis, using computed tomography (CT) as the gold-standard reference method.

METHOD

The ulnar head, radiocarpal and second to fifth MCP joints in 26 patients with SLE - 9 classified as having rhupus syndrome, 10 as having Jaccoud's arthropathy (JA) and 7 as having non-deforming non-erosive (NDNE) arthritis - were subdivided into areas and bilaterally evaluated for the presence of bone erosion by CT and US. On CT, erosion volume was scored according to the outcome measures in rheumatology-rheumatoid arthritis magnetic resonance imaging (OMERACT-RAMRIS) score. On US, erosions were semi-quantitatively scored 0-3 according to scoring by ultrasound structural erosion (ScUSSe) systems.

RESULTS

Erosions were detected by CT in 92/728 areas (12.6 %) and by US in 43/728 areas (5.9 %). Sensitivity, specificity and accuracy of US overall was 36 %, 98 % and 90 % compared with 57 %, 98 % and 93 % in the dorsal and lateral aspects of the second and fifth MCP, which were identified as areas with the best US reliability. Adding wrist joints would capture a larger number of erosions without affecting the accuracy. US detected 90.0 % of CT erosions with bone volume loss >20 % and 51.2 % of erosions with bone volume loss >10 %. Patients with rhupus had a greater number of larger erosions than those with JA or NDNE arthritis, with prevalent involvement of the MCP joints. Overall reliability of US in detecting bone erosions was moderate for rhupus syndrome (0.55) and JA (0.58), but poor for NDNE arthritis (0.10).

CONCLUSION

US had moderate sensitivity and excellent specificity for detection and semi-quantitative assessment of bone erosions in SLE.

Spontaneous flexor tendon rupture due to an insufficiency fracture of the hamate hook in a patient with systemic lupus erythematosus: A case report

INTRODUCTION

Spontaneous flexor tendon rupture is usually caused by trauma, systemic diseases, or carpal bone and joint disorders. Here we report a case of spontaneous flexor tendon rupture occurring in a systemic lupus erythematosus (SLE) patient following nonunion of the hamate hook after an insufficiency fracture, and which was also associated with tendon degeneration caused by SLE.

CASE PRESENTATION

A 57-year-old woman was diagnosed with SLE 22 years ago and being treated with oral prednisolone. She became unable to flex her left little finger without any history of trauma or sporting activity. CT showed nonunion of the hamate hook. MRI showed rupture of the flexor digitorum profundus tendon of the little finger. We performed tendon transfer and excision of the hamate hook. She recovered active flexion of the little finger at 4 months postoperatively with full satisfaction.

DISCUSSION

There was no history of trauma that could have caused nonunion of the hamate hook. We considered that the insufficiency fracture of the hamate hook occurred as a result of osteoporosis caused by SLE and long-term steroid use. Nonunion of the hamate hook caused mechanical attrition of the tendons, and in combination with the tendon degeneration caused by SLE, further resulted in rupture of the flexor tendon.

CONCLUSION

When we encounter a case of spontaneous flexor tendon rupture in a patient with systemic disease such as SLE or long-term steroid use, attention should be paid to the state of the carpal bones and joints as they sometimes accompany unexpected causes.