In an early SLE cohort the ACR-1997, SLICC-2012 and EULAR/ACR-2019 criteria classify non-overlapping groups of patients: use of all three criteria ensures optimal capture for clinical studies while their modification earlier classification and treatment

Can we predict kidney involvement in patients with systemic lupus erythematosus? A retrospective cohort study with independent validation

OBJECTIVES

To discern predictive factors for incident kidney involvement in patients with SLE.

METHODS

Patients with SLE from the 'Attikon' Lupus cohort were monitored for LN, defined by kidney histology and/or classification criteria. Demographic and clinical characteristics at baseline were compared against patients who did not develop LN. LN-free Kaplan-Meier survival curves were generated. A multivariate Cox proportional hazards model was used to identify independent predictors of LN. Independent validation was performed in the University of Crete Lupus registry.

RESULTS

Among the 570 patients in the derivation cohort, 59 exhibited LN as their initial presentation, while an additional 66 developed LN during the follow-up period (collectively, 21.9% incidence). In the latter group, baseline factors predictive of subsequent kidney involvement were male sex [multivariable-adjusted hazard ratio (aHR) 4.31; 95% CI: 1.82, 10.2], age of SLE diagnosis below 26 years (aHR 3.71; 95% CI: 1.84, 7.48), high anti-dsDNA titre (aHR 2.48; 95% CI: 1.03, 5.97) and low C3 and/or C4 (although not statistically significant, aHR 2.24; 95% CI: 0.83, 6.05; P = 0.11). A combination of these factors at time of diagnosis conferred an almost 90-fold risk compared with serologically inactive, older, female patients (aHR 88.77; 95% CI: 18.75, 420.41), signifying a very high-risk group. Independent validation in the Crete Lupus registry showed concordant results with the original cohort.

CONCLUSION

Male sex, younger age and serological activity at SLE diagnosis are strongly associated with subsequent kidney involvement. Vigilant surveillance and consideration of early use of disease-modifying drugs is warranted in these subsets of patients.

Thyroid hormones in systemic lupus erythematosus: The catalyst for disease progression?

OBJECTIVE

The study aimed to investigate the impact of varying thyroid function statuses on clinical and laboratory indicators in patients with systemic lupus erythematosus (SLE).

METHODS

A retrospective analysis was conducted on 258 patients with SLE, who were stratified according to thyroid function, renal involvement, and disease activity. The predictive value of thyroid hormones was evaluated using a receiver operating characteristic (ROC) curve.

RESULTS

Among the 258 patients with SLE, 141 were classified as the normal group, while 117 exhibited thyroid hormone abnormalities, categorized into hypothyroidism (N=112) and hyperthyroidism (N=5) groups. Serum levels of FT3 and FT4 positively correlate with total protein and albumin, while negatively correlating with the SLE Disease Activity Index 2K (SLEDAI-2K) and 24-hour urinary protein (24hUP) (P<0.05). Compared to individuals without renal involvement, those with renal involvement exhibited lower levels of FT3 and FT4 (3.35±0.99 vs. 4.07±2.22, 12.92±3.14 vs. 14.63±3.39, P=0.001), along with elevated thyroid-stimulating hormone (TSH) levels (7.08±14.40 vs. 5.28±12.48, P=0.343). The subgroups in euthyroid (n=86) and hypothyroid (n=93) of SLE patients with renal involvement exhibited different characteristics (P<0.05). The levels of FT3 gradually decreased with increase of disease activity. The areas under the ROC curve of FT3, FT4, TSH and their combination were 0.651, 0.654, 0.643, 0.669, respectively (P<0.05).

CONCLUSIONS

The correlation between thyroid function and the severity of SLE is significant, SLE patients with hypothyroidism exhibit more pronounced disease manifestations and an elevated risk of organ damage. SLE patients with low levels of FT3 and FT4 are prone to progressing to nephritis.

Pregnancy outcomes and risk factors for thrombocytopenia in pregnant patients with systemic lupus erythematosus

BACKGROUND

To compare pregnancy outcomes between systemic lupus erythematosus (SLE) patients with thrombocytopenia and those without, and to develop a nomogram for assessing the risk of developing SLE-related thrombocytopenia during pregnancy.

METHODS

Clinical data from 178 pregnant patients with SLE were analyzed. Patients were classified into thrombocytopenia and normal platelet groups using a platelet count cutoff of < 100 × 10^9/L. Pregnancy outcomes were compared between these groups. A nomogram was developed to identify factors associated with thrombocytopenia based on univariate and multivariable logistic regression analyses. The performance of the nomogram was assessed through receiver operating characteristic (ROC) curves, calibration curves, and decision curve analysis (DCA).

RESULTS

Among the 178 patients, 34 were in the thrombocytopenia group and 144 in the normal platelet group. SLE patients with thrombocytopenia had a significantly higher rate of active disease (55.9% vs. 5.6%, P < 0.001) and a higher SLE-Pregnancy Disease Activity Index (SLEPDAI) (4.71 ± 3.04 vs. 2.29 ± 1.88, P < 0.001). When comparing patients with thrombocytopenia (categorized by platelet counts < 50 × 10^9/L and > 50 × 10^9/L) to the control group, the incidence of severe preeclampsia (20.00% vs. 15.79% vs. 4.86%, P = 0.027) and postpartum hemorrhage (26.32% vs. 6.67% vs. 3.47%, P = 0.007) was also significantly higher in the thrombocytopenia group. This group exhibited elevated rates of pregnancy loss (73.33% vs. 31.58% vs. 4.17%, P < 0.001) and stillbirth (20.00% vs. 15.79% vs. 0.69%, P < 0.001). Active disease, previous abortion, and anti-β2GPI antibodies positivity were identified as independent factors of developing SLE-related thrombocytopenia during pregnancy. The area under the curve for the nomogram was 0.833 (95% CI: 0.753-0.913). Both the calibration curve and DCA indicated that the model performed well.

CONCLUSION

Thrombocytopenia in pregnant patients with SLE is associated with increased disease activity and a higher incidence of adverse outcomes, including pregnancy loss and stillbirth. The nomogram for developing thrombocytopenia during pregnancy may help clinicians improve the management of this group of patients.

CLINICAL TRIAL NUMBER

not applicable.

Performance of the Systemic Lupus Erythematosus Risk Probability Index (SLERPI) in a cohort of Colombian population

OBJECTIVE

To evaluate the performance of the Systemic Lupus Erythematosus Risk Probability Index (SLERPI) in Colombian patients with systemic lupus erythematosus (SLE).

METHODS

The Colombian cohort included 435 SLE patients and 430 controls with other autoimmune diseases (ADs). Clinical and serological data were collected, and SLE was indicated by SLERPI scores > 7. The American College of Rheumatology (ACR)-1997, Systemic Lupus International Collaborating Clinics (SLICC)-2012, and European League Against Rheumatism (EULAR)/ACR-2019 criteria were used as reference standards. The impact of overt polyautoimmunity (PolyA) on SLERPI performance was assessed. Additionally, multivariate lineal regression analysis was performed to evaluate the contribution of SLERPI features to the overall SLERPI score.

RESULTS

SLE patients had higher SLERPI scores (P < 0.0001), with almost 90% meeting "definite" lupus criteria. Main factors influencing SLERPI included immunological disorder (β:44.75, P < 0.0001), malar/maculopapular rash (β:18.43, P < 0.0001), and anti-nuclear antibody positivity (β:15.65, P < 0.0001). In contrast, subacute cutaneous lupus erythematosus/discoid lupus erythematosus (β:2.40, P > 0.05) and interstitial lung disease (β:-21.58, P > 0.05) were not significant factors to the overall SLERPI score. SLERPI demonstrated high sensitivity for SLE, both for the overall SLE group and for those without overt PolyA (95.4% and 94.6%, respectively), but had relatively low specificity (92.8% and 93.7%, respectively). The model showed high sensitivity for hematological lupus (98.8%) and lupus nephritis (96.0%), but low sensitivity for neuropsychiatric lupus (93.2%). Compared to the ACR-1997, SLICC-2012 and EULAR/ACR-2019 criteria, SLERPI yielded the highest sensitivity and lowest specificity.

CONCLUSION

SLERPI efficiently identified SLE patients in a Colombian cohort, showing high sensitivity but low specificity. The model effectively distinguishes SLE patients, even in the presence of concurrent overt PolyA. Key Points •SLERPI has a high sensitivity, but low specificity compared to ACR-1997, SLICC-2012 and EULAR/ACR-2019 criteria in the Colombian population. •Within the SLERPI score, immunological disorder, malar/maculopapular rash, and anti-nuclear antibody positivity are the strongest predictors of SLE. •SLERPI model can efficiently distinguish patients with SLE, regardless of concomitant overt PolyA. •SLERPI demonstrates high sensitivity in identifying hematological and nephritic subphenotypes of SLE.

Systemic lupus international collaborating clinics-2012 and European league against rheumatism/American college of rheumatology-2019 classification criteria for systemic lupus erythematosus associated with childhood-onset auto-immune cytopenia

INTRODUCTION

Systemic Lupus Erythematosus (SLE) can be diagnosed using the 2012 criteria of the Systemic Lupus International Collaborating Clinics (SLICC) and, more recently, the 2019 criteria of the European League Against Rheumatism/American College of Rheumatology (EULAR/ACR). Hematological involvement is scored differently by these classifications. Our objective was to compare both criteria in a cohort of children with autoimmune cytopenia (AIC)-associated SLE.

METHOD

We included 79 patients with childhood-onset AIC as the first manifestations of SLE.

RESULTS

The median age at SLE diagnosis was 14.5 years (1.1-21.4 years). The SLICC criteria were fulfilled by 76/79 (96%) patients and the EULAR/ACR criteria by 72/79 (91%) patients during follow-up. The SLICC and EULAR/ACR criteria were discordant (not concomitantly fulfilled) in 25/79 (32%) patients. Non-hematological clinical manifestations were more frequently observed in SLE diagnosis when the criteria were concordant (30/54, 56%) than when they were not (5/25, 20%) (p = 0.004). In 16/25 (64%) discordant patients, the SLICC criteria allowed earlier diagnosis of SLE. Finally, the attribution of a maximum weight of 6 to the hematological involvement of the EULAR/ACR criteria increased the sensitivity thereof from 63/79 (80%) to 76/79 (96%) in our population.

CONCLUSION

The SLICC 2012 and EULAR/ACR 2019 criteria do not effectively diagnose SLE in children when AIC is the predominant feature. The SLICC criteria appear to be more effective in this population of SLE patients. An increase in the maximum weight of hematological involvement to 6 increases the sensitivity of the EULAR/ACR criteria for SLE diagnosis in children.

Sensitivity of classification criteria from time of diagnosis in an incident systemic lupus erythematosus cohort: a population-based study from Norway

OBJECTIVES

To compare the sensitivity of 2019 European Alliance of Associations for Rheumatology/American College of Rheumatology (EULAR/ACR) classification criteria against 1997 ACR criteria for systemic lupus erythematosus (SLE), for incident SLE cases in the presumably complete population-based Nor-SLE cohort from Southeast Norway (2.9 million inhabitants).

METHODS

All cases International Statistical Classification of Diseases and Related Health Problems, Tenth Revision (ICD-10) coded as SLE during 2000-2017 were individually reviewed. Those with a confirmed SLE diagnosis by expert clinical assessment were included in the Nor-SLE cohort. Core clinical data were recorded, and the cases were classified according to 2019 EULAR/ACR and 1997 ACR criteria. Juvenile SLE was defined as <16 years at diagnosis and adult SLE was defined as ≥16 years at diagnosis.

RESULTS

We included 737 incident SLE cases (701 adults, 36 juveniles). At diagnosis, 2019 EULAR/ACR criteria were more sensitive than 1997 ACR criteria for adults (91.6% vs 77.3%; p<0.001), but not for juveniles (97.2% vs 88.9%). The 2019 EULAR/ACR counts at diagnosis differed by age group and ethnicity, being higher in young cases and those originating from Asia. From time of diagnosis to study end the fulfilment rate of 2019 EULAR/ACR criteria for the adult cohort increased from 92.5% and 86.5% to 94.6% and 91.0%, respectively, for females and males (mean disease duration of 7.5 years).

CONCLUSION

Showing 92% criteria fulfilment already at time of SLE diagnosis by 2019 EULAR/ACR criteria versus 77% by 1997 ACR criteria, the results from this population-based study suggest that the 2019 EULAR/ACR criteria will achieve its goal of capturing more early-SLE cases for clinical trials.

Clinical trial eligibility of a real-world connective tissue disease cohort: Results from the LEAP cohort

INTRODUCTION

Classification criteria aim to identify a homogenous population of patients for research. We aimed to quantify how well phase-III trials in connective tissue diseases (CTDs) represent a real-world cohort.

METHODS

A comprehensive review of all major published phase-III trials in CTDs was performed (clinicaltrials.gov). Classification criteria utilised most commonly in clinical trials were applied to a multicentre unselected CTD cohort.

RESULTS

There were 42 CTD trials identified, with no trials in mixed (MCTD) or undifferentiated CTD (UCTD). The majority of trials (N = 38, 90 %) required patients to meet classification criteria for their respective disease. Eight (19.0 %) excluded patients with overlapping CTDs and a further two (4.8 %) excluded specific overlapping features, such as pulmonary arterial hypertension. One study explicitly allowed overlap syndromes. Our real-world CTD cohort included 391 patients. Patients with UCTD or MCTD (91/391, 23.3 %) would be excluded from participation in clinical trials for not having an eligible diagnosis. Of patients with primary Sjögren's syndrome (pSS), SLE, systemic sclerosis (SSc) or idiopathic inflammatory myopathy (IIM), 211/300 (70.3 %) met the classification criteria for their respective diagnosis and 24/211 (11.4 %) met criteria for >1 CTD. In total, 187/391 (47.8 %) would be eligible for recruitment, based upon their physician diagnosis, and most stringent trial eligibility criteria.

CONCLUSION

In an unselected, real-world CTD cohort, up to half of patients are ineligible for clinical trials due to not meeting classification criteria, overlapping features or a lack of trials within their primary disease. To address this inequality in access to novel therapies, clinical trial design should evolve eligibility criteria in CTDs.

Usefulness of platelet count to predict concomitant valvular heart disease in patients with systemic lupus erythematosus

Background

Although the prevalence rate of valvular heart disease (VHD) is high in patients with systemic lupus erythematosus (SLE), the predictive factors of concomitant VHD have not been fully evaluated.

Methods and results

Among 288 patients with SLE who underwent transthoracic echocardiography at Kumamoto University Hospital from 2016 to 2021, 241 patients with sufficient echocardiographic data were retrospectively analysed. Among them, 22 (9 %) had VHD (10 had mitral regurgitation, 3 had aortic regurgitation, 6 had tricuspid regurgitation, 1 had mitral regurgitation and tricuspid regurgitation, and 2 had a prosthetic cardiac valve). After excluding the two patients with a prosthetic cardiac valve, we divided the remaining patients into two groups: the VHD group and non-VHD group. Multivariate logistic regression analysis revealed that age and the platelet count were significantly and independently associated with having VHD (age: odds ratio, 1.06; 95 % confidence interval, 1.02-1.10; p < 0.01) (platelet count: odds ratio, 0.99; 95 % confidence interval, 0.98-1.00; p < 0.05). After excluding 95 patients aged < 40 years, receiver operating characteristic analysis revealed that the area under the curve of the platelet count for prediction of VHD was 0.73 with an optimal cut-off value of 166.5 × 103/µL (sensitivity: 76.6 %, specificity: 60.0 %). Among patients with a low platelet count (<166.5 × 103/µL), the rate of having VHD was 29 % (12/41 patients). However, among those with a high platelet count (≥166.5 × 103/µL), this rate was only 8 % (8/103 patients).

Conclusion

The platelet count is useful to predict concomitant VHD in middle-aged and older patients with SLE.

Comparison of systemic lupus international collaborating clinics 2012 classification criteria and European league against rheumatism/American college of rheumatology 2019 classification criteria for early detection of childhood onset systemic lupus erythematosus (multi-center study)

OBJECTIVE

To assess the performance of the new EULAR/ACR criteria, particularly for early detection of cSLE, in comparison to the SLICC criteria among the pediatric population in multiple centers in Saudi Arabia.

METHODS

We conducted a retrospective study that enrolled pediatric patients up to the age of 14 years who've been diagnosed with SLE and followed in pediatric rheumatology clinics at 9 multi-tertiary hospitals in Saudi Arabia from 2010 to 2021 as a case group and were compared to a similar group of pediatric patients who've had defined rheumatological diseases other than SLE with a positive ANA titer (≥1:80) as controls. In total, 245 patients were included and distributed as 129 cases (diagnosed by expert pediatric rheumatologists) versus 116 patients in the control group. All relevant clinical information, including history, physical examination findings, and laboratory tests, was documented at the initial presentations. Then, the two sets of SLE classification criteria were applied to both groups to define who's going to meet both or either one of them. The exclusion criteria included those who had insufficient data or had overlapping or undifferentiated diseases. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), receiver operating curve (ROC), and accuracy were calculated for SLICC 2012 and EULAR/ACR 2019 criteria (total scores≥ 10 and ≥ 13). We performed a Chi-squared test to compare sensitivity and specificity of SLICC 2012 and EULAR/ACR 2019.

RESULTS

For SLICC (cut-off ≥4 criteria), the sensitivity was found to be 96.9% (95% CI 92.6%-99.4%) and the specificity was 94.8% (95% CI 89.6%-98.32%), with PPV and NPV of 95.4% and 96.5%, respectively. The ROC for it was 0.96 (95% CI 0.93-0.99), and this criterion had an accuracy of 95%. Regarding EULAR/ACR (total score ≥ 10), the performance measure showed a sensitivity of 99.2% and a specificity of 86.2%. Similarly, PPV was 88.9%; while NPV was a little higher (99.0%) than SLICC. The ROC for EULAR/ACR (total score ≥ 10) was 0.93 (95% CI 0.89-0.96), and this criterion had an accuracy of 93%. However, there was no statistically significant difference between the sensitivity and specificity of either using SLICC or EULAR/ACR (total score ≥ 10), as reflected by a p-value of 0.86 using the Chi-squared test. Although applying the EULAR/ACR with a total score of ≥ 13 revealed lower sensitivity (93.8%) than both the SLICC and the EULAR/ACR (total score ≥ 10), the specificity for it was found to increase up to 91.4% (85.7-96.2%) compared to the (86.2%) specificity of the EULAR/ACR (total score ≥ 10).

CONCLUSION

In this cohort among the Saudi population with childhood-onset SLE, the new EULAR/ACR 2019 criteria efficiently enable early detection of SLE, although a more frequent rate of false positives was observed with them. Escalating the total score from ≥ 10 to ≥ 13 in the cSLE population improved the specificity close to that of SLICC 2012. Further prospective studies in pediatrics need to be done for the validation of a cut- off score of ≥ 13 in cSLE rather than the traditional score of ≥ 10 in aSLE.

SLE criteria are by necessity still based on clinical (and immunological) criteria items

INTRODUCTION

The 2019 European League Against Rheumatism/American College of Rheumatology (EULAR/ACR) classification criteria for systemic lupus erythematosus (SLE) rely on clinical and routine immunological items. The criteria have anti-nuclear antibodies (ANA) as an obligatory entry criterion; items are weighted and ordered in domains. While demonstrating good sensitivity and specificity, the lack of a more molecular approach to some came as a disappointment.

AREAS COVERED

Based on a non-systematic literature search, this review covers items investigated in the EULAR/ACR classification criteria project, but not included in the set of criteria. It demonstrates data on the importance of the criteria and analyses implications of multiomics studies started around the same time as the criteria project. We also discuss data on the type-I interferon signature and on other cytokines, as well as on complement proteins and their split products. The final part deals with the variability in disease and the apparently random pattern of autoantibodies and organ manifestations in individual patients.

EXPERT OPINION

We believe that the EULAR/ACR criteria are a relevant step toward the right direction. A more uniform molecular approach will not be feasible as long as the molecular mechanisms underlying the tendency toward producing multiple autoantibodies are not better understood.

Classifying systemic lupus erythematosus using laboratory items alone: a preliminary study

OBJECTIVES

To explore the performance of laboratory items alone in systemic lupus erythematosus (SLE) classification.

METHODS

Our cohort consisted of 352 and 385 (control) patients with and without SLE. This study evaluated the performance of the American College of Rheumatology (ACR)-1997, Systemic Lupus International Collaborating Clinics (SLICC)-2012, European League Against Rheumatism (EULAR)/ACR-2019, and Systemic Lupus Erythematosus Risk Probability Index (SLERPI) using laboratory items alone, including blood and urine test results.

RESULTS

The median ratio of laboratory items/total items was 66.7%, 75.0%, 60.4%, and 77.4% in ACR-1997, SLICC-2012, EULAR/ACR-2019, and SLERPI, respectively. After including laboratory items alone, the sensitivity of ACR-1997, SLICC-2012, EULAR/ACR-2019, and SLERPI was 31.3% (95% confidence interval [CI]: 26.4%-36.4%), 79.8% (95% CI: 75.3%-83.9%), 75.9% (95% CI: 71.0%-80.2%), and 85.2% (95% CI: 81.1%-88.8%), respectively. We referenced the SLERPI and removed the additional restrictions, i.e., SLICC-2012 criteria only needs to fulfill at least four items (mSLICC-2012) and EULAR/ACR-2019 criteria needs to have ≥ 10 points (mEULAR/ACR-2019) to qualify for SLE classification. The mSLICC-2012 and mEULAR/ACR-2019 criteria, including laboratory items alone, newly identified 13 and 25 patients, respectively. Based on laboratory items alone, the combination of mSLICC-2012, mEULAR/ACR-2019, and SLERPI identified 348 patients with an improved sensitivity of 90.6% (95% CI: 87.1%-93.5%). Patients, who were classified according to the mEULAR/ACR-2019 criteria, all met the other criteria.

CONCLUSION

Incorporating laboratory items alone was clinically feasible to help identify SLE. SLERPI and SLICC-2012, using laboratory items alone, were more worthwhile to promote in the clinic compared with EULAR/ACR-2019. Key Points • Laboratory items play a crucial role in the SLE classification criteria, and incorporating laboratory items alone was clinically feasible to help in the identification of SLE. • The SLERPI and SLICC-2012, using laboratory items alone, were more worthwhile to promote in the clinic compared with EULAR/ACR-2019, and the combination of the two could further improve the sensitivity. • The relative simplicity of evaluating laboratory indices may help nonrheumatologists and inexperienced rheumatologists to identify SLE more quickly, thereby reducing the risk of delayed diagnosis in patients.

Systemic Lupus Erythematosus: How Machine Learning Can Help Distinguish between Infections and Flares

Systemic Lupus Erythematosus (SLE) is a multifaceted autoimmune ailment that impacts multiple bodily systems and manifests with varied clinical manifestations. Early detection is considered the most effective way to save patients' lives, but detecting severe SLE activity in its early stages is proving to be a formidable challenge. Consequently, this work advocates the use of Machine Learning (ML) algorithms for the diagnosis of SLE flares in the context of infections. In the pursuit of this research, the Random Forest (RF) method has been employed due to its performance attributes. With RF, our objective is to uncover patterns within the patient data. Multiple ML techniques have been scrutinized within this investigation. The proposed system exhibited around a 7.49% enhancement in accuracy when compared to k-Nearest Neighbors (KNN) algorithm. In contrast, the Support Vector Machine (SVM), Binary Linear Discriminant Analysis (BLDA), Decision Trees (DT) and Linear Regression (LR) methods demonstrated inferior performance, with respective values around 81%, 78%, 84% and 69%. It is noteworthy that the proposed method displayed a superior area under the curve (AUC) and balanced accuracy (both around 94%) in comparison to other ML approaches. These outcomes underscore the feasibility of crafting an automated diagnostic support method for SLE patients grounded in ML systems.

Serum Metabolic Fingerprints Characterize Systemic Lupus Erythematosus

Metabolic fingerprints in serum characterize diverse diseases for diagnostics and biomarker discovery. The identification of systemic lupus erythematosus (SLE) by serum metabolic fingerprints (SMFs) will facilitate precision medicine in SLE in an early and designed manner. Here, a discovery cohort of 731 individuals including 357 SLE patients and 374 healthy controls (HCs), and a validation cohort of 184 individuals (SLE/HC, 91/93) are constructed. Each SMF is directly recorded by nano-assisted laser desorption/ionization mass spectrometry (LDI MS) within 1 minute using 1 µL of native serum, which contains 908 mass to charge features. Sparse learning of SMFs achieves the SLE identification with sensitivity/specificity and area-under-the-curve (AUC) up to 86.0%/92.0% and 0.950 for the discovery cohort. For the independent validation cohort, it exhibits no performance loss by affording the sensitivity/specificity and AUC of 89.0%/100.0% and 0.992. Notably, a metabolic biomarker panel is screened out from the SMFs, demonstrating the unique metabolic pattern of SLE patients different from both HCs and rheumatoid arthritis patients. In conclusion, SMFs characterize SLE by revealing its unique metabolic pattern. Different regulation of small molecule metabolites contributes to the precise diagnosis of autoimmune disease and further exploration of the pathogenic mechanisms.

Management of systemic lupus erythematosus: A new scenario

The introduction of targeted biological agents in systemic lupus erythematosus (SLE) has created a momentum for improving overall disease management and patients' prognosis. To achieve this, a comprehensive strategy is required spanning the entire patient journey from diagnosis to prevention and management of late complications and comorbidities. In this review, we focus on four aspects that are closely linked to SLE prognosis, namely early disease recognition and treatment initiation, reduction of the cumulative glucocorticoid exposure, attainment of well-defined targets of remission and low disease activity, prevention of flares and, kidney-protective strategies with non-immune-directed agents. We review the recent literature related to these topics in conjunction with the existing treatment recommendations, highlighting areas of uncertainty and providing guidance towards facilitating the care of SLE patients.

Reframing health disparities in SLE: A critical reassessment of racial and ethnic differences in lupus disease outcomes

Health disparities in the prevalence and outcomes of systemic lupus erythematosus (SLE) are well documented across racial and ethnic groups. Similar to other chronic diseases, differences in disease severity among individuals with SLE are likely influenced by both genetic predisposition and multiple social determinants of health. However, research in SLE that jointly examines the genetic and environmental contributions to the disease course is limited, resulting in an incomplete understanding of the biologic and social mechanisms that underly health disparities. While research on health disparities can reveal inequalities and inform resource allocation to improve outcomes, research that relies on racial and ethnic categories to describe diverse groups of people can pose challenges. Additionally, results from research comparing outcomes across socially constructed groups without considering other contributing factors can be misleading. We herein comprehensively examine existing literature on health disparities in SLE, including both clinical studies that examine the relationship between self-reported race and ethnicity and disease outcomes and studies that explore the relationships between genomics and lupus outcomes. Having surveyed this body of research, we propose a framework for research examining health disparities in SLE, including ways to mitigate bias in future studies.

Clinical patterns of disease: From early systemic lupus erythematosus to late-onset disease

Systemic lupus erythematosus (SLE) is a complex disease with an insidious clinical presentation. In up to half of the cases, SLE onset is characterized by clinical and serological manifestations that, although specific, are insufficient to fulfill the classification criteria. This condition, called incomplete SLE, could be as challenging as the definite and classifiable SLE and requires to be treated according to the severity of clinical manifestations. In addition, an early SLE diagnosis and therapeutic intervention can positively influence the disease outcome, including remission rate and damage accrual. After diagnosis, the disease course is relapsing-remitting for most patients. Time in remission and cumulative glucocorticoid exposure are the most important factors for prognosis. Therefore, timely identification of SLE clinical patterns may help tailor the therapeutic intervention to the disease course. Late-onset SLE is rare but more often associated with delayed diagnosis and a higher incidence of comorbidities, including Sjogren's syndrome. This review focuses on the SLE disease course, providing actionable strategies for early diagnosis, an overview of the possible clinical patterns of SLE, and the clinical variation associated with the different age-at-onset SLE groups.

Evaluation of the EULAR/American College of Rheumatology Classification Criteria for Systemic Lupus Erythematosus in a Population-Based Registry

OBJECTIVE

Using the Manhattan Lupus Surveillance Program, a multiracial/ethnic population-based registry, we aimed to compare 3 commonly used classification criteria for systemic lupus erythematosus (SLE) to identify unique cases and determine the incidence and prevalence of SLE using the EULAR/American College of Rheumatology (ACR) criteria.

METHODS

SLE cases were defined as fulfilling the 1997 ACR, the Systemic Lupus International Collaborating Clinics (SLICC), or the EULAR/ACR classification criteria. We quantified the number of cases uniquely associated with each and the number fulfilling all 3 criteria. Prevalence and incidence using the EULAR/ACR classification criteria and associated 95% confidence intervals (95% CIs) were calculated.

RESULTS

A total of 1,497 cases fulfilled at least 1 of the 3 classification criteria, with 1,008 (67.3%) meeting all 3 classifications, 138 (9.2%) fulfilling only the SLICC criteria, 35 (2.3%) fulfilling only the 1997 ACR criteria, and 34 (2.3%) uniquely fulfilling the EULAR/ACR criteria. Patients solely satisfying the EULAR/ACR criteria had <4 manifestations. The majority classified only by the 1997 ACR criteria did not meet any of the defined immunologic criteria. Patients fulfilling only the SLICC criteria did so based on the presence of features unique to this system. Using the EULAR/ACR classification criteria, age-adjusted overall prevalence and incidence rates of SLE in Manhattan were 59.6 (95% CI 55.9-63.4) and 4.9 (95% CI 4.3-5.5) per 100,000 population, with age-adjusted prevalence and incidence rates highest among non-Hispanic Black female patients.

CONCLUSION

Applying the 3 commonly used classification criteria to a population-based registry identified patients with SLE fulfilling only 1 validated definition. The most recently developed EULAR/ACR classification criteria revealed prevalence and incidence estimates similar to those previously established for the ACR and SLICC classification schemes.

Lupus spectrum ambiguity has long-term negative implications for patients

Lupus is a complex disease that is often difficult to diagnose. Risks of diagnostic delays include non-specific signs and symptoms that mimic other diseases and a lack of diagnostic criteria and referral pathways for non-specialists. To address these issues, we convened a series of virtual meetings with members of our Addressing Lupus Pillars for Health Advancement clinical care team. Meeting participants included lupus physicians, treatment developers from biotechnology, patient advocacy group representatives from the Lupus Foundation of America and advocacy/government consultants. Causes and consequences of ambiguity in diagnosis and diagnostic delays were evaluated through historical, experiential and evidence-based accounts (survey data, literature reviews and patient testimonials). Discussions highlighted the need for a clearer understanding of the definition of lupus, the natural history of the disease and the need for advancements in biotechnology to support an accurate and timely diagnosis with the potential development of a lupus spectrum.

The impact of normal serum complement levels on the disease classification and clinical characteristics in systemic lupus erythematosus

BACKGROUND

Some patients have normal levels of complement during the diagnosis of systemic lupus erythematosus (SLE), although decreased serum levels of complement are a hallmark of the active phase of the disease. This study investigated the clinical characteristics, impact on the classification of SLE, and the prognosis of patients with SLE who had normal serum complement levels at initial diagnosis (N-com).

METHODS

We evaluated 21 patients with N-com and 96 patients with hypocomplementemia at the initial diagnosis of SLE (H-com). The classification rates among the American College of Rheumatology (ACR) 1997, Systemic Lupus International Collaborating Clinics (SLICC) 2012, European League Against Rheumatism (EULAR)/ACR 2019 criteria, and clinical and immunological involvements were compared between SLE patients with N-com and H-com. Relapse and organ damage based on the SLICC/ACR damage index were also evaluated.

RESULTS

The classification rates of SLE were not significantly different in the ACR, SLICC, and EULAR/ACR criteria between the N-com and H-com groups. Patients with N-com had no significant differences in the classification rates among the three criteria, whereas patients with H-com had lower classification rates in the ACR criteria than in the SLICC criteria. A lower incidence of renal manifestation, less positivity for anti-dsDNA antibody, and a higher incidence of fever were observed in patients with N-com than in those with H-com. The occurrence of relapse and organ damage was not significantly different between patients with N-com and H-com.

CONCLUSION

Patients with N-com were less involved in renal manifestation and anti-dsDNA antibody positivity but had a higher incidence of fever than those with H-com, while having no disadvantage in SLE classification processes. Serum complement levels at the initial diagnosis of SLE may not predict prognosis.

Evaluating performance of the 2019 EULAR/ACR, 2012 SLICC, and 1997 ACR criteria for classifying adult-onset and childhood-onset systemic lupus erythematosus: A systematic review and meta-analysis

Introduction

The American College of Rheumatology (ACR) 1997, Systemic Lupus International Collaborating Clinics (SLICC) 2012, and European League Against Rheumatism (EULAR)/ACR 2019 SLE criteria are often used to classify patients with adult-onset and childhood-onset systemic lupus erythematosus (SLE) in clinical practice because there are currently no diagnostic criteria for SLE. However, there is scarce evidence regarding which criteria are best for diagnosing patients with adult-onset and childhood-onset SLE.

Methods

We searched Medline and Scopus databases for English-language articles from inception through October 2021. Data were extracted from the included publications by two independent reviewers. We performed bivariate meta-analysis with a random-effects model to pool diagnostic parameters. Meta-regression and subgroup analyses were performed to explore heterogeneity sources. We used network meta-analysis to compare diagnosis performance among the three criteria and ranked them in descending order. Publication bias was assessed using Deeks' funnel plot.

Results

We included 29 studies for systematic review and meta-analysis. Of these, 18 studies involved adult-onset SLE and 11 studies involved childhood-onset SLE. The pooled sensitivities of the three criteria for diagnosis of adult-onset SLE were comparable between SLICC 2012 and EULAR/ACR 2019 [95.86, 95% confidence interval (CI) 92.28-97.81 vs. 94.79, 95% CI 92.03-96.63]; pooled specificity was highest in ACR 1997 (92.24, 95% CI 87.06-95.46). In childhood-onset SLE, pooled sensitivity was highest in SLICC 2012 (93.76, 95% CI 89.45-96.39), and pooled specificity was highest in ACR 1997 (95.89, 95% CI 91.73-98.00). In network meta-analysis, the pooled diagnostic odds ratio ranked highest for EULAR/ACR 2019 (131.570, 95% CI 61.50-281.47) in adult-onset SLE and ranked highest for SLICC 2012 (191.07, 95% CI 76.06-480.01) in childhood-onset SLE. Deeks' funnel plot showed no publication bias.

Conclusion

We found that the diagnostic performance of the ACR 1997, SLICC 2012, and EULAR/ACR 2019 criteria differed between adult-onset and childhood-onset SLE. EULAR/ACR 2019 performed best for adult-onset SLE and SLICC 2012 was best for childhood-onset SLE in classifying patients with SLE.

Systematic review registration

[www.ClinicalTrials.gov], identifier [CRD420 21281586].

Performance of the New 2019 European Alliance of Associations for Rheumatology/American College of Rheumatology Systemic Lupus Erythematosus Classification Criteria in a Large Unicentric Cohort

Background: The recently published 2019 American College of Rheumatology/European Alliance of Associations for Rheumatology (ACR/EULAR) classification criteria for systemic lupus erythematosus (SLE) were developed to increase the reliability and identification of SLE, especially in early disease. With the emergence of several new drugs for SLE, identifying and treating patients early are more important than ever. Methods: Data of 446 SLE patients evaluated in our center between 1996−2019 and 226 controls with other autoimmune diseases evaluated between 2001−2022 were retrospectively analyzed. The sensitivity and specificity of the 2019 ACR/EULAR criteria were compared to the 2012 SLICC and the 1997 ACR criteria. Results: The 2019 ACR/EULAR criteria showed very good sensitivity (86.6%) compared to the 1997 ACR criteria (76.7%), p < 0.001, with a trend toward significance compared to the 2012 SLICC criteria (83.6%), p = 0.072. Their sensitivity remained high (87.6%) in patients with a short disease duration. The specificity of the 2019 ACR/EULAR criteria (91.2%) was statistically lower than the 2012 SLICC (96.0%) and 1997 ACR criteria (95.1%), p = 0.007 and p = 0.012, respectively, but still had a very high value. A total of 22 controls (9.7%) fulfilled at least one set of criteria (15 patients with MCTD, 5 with UCTD, and 2 with SSc). Conclusion: In this large real-life cohort, the 2019 ACR/EULAR criteria had very good performance compared to the 2012 SLICC and 1997 ACR criteria.

Diagnostic accuracy of the European League against rheumatism/American College of Rheumatology-2019 versus the Systemic Lupus International Collaborating Clinics-2012 versus the ACR-1997 classification criteria in adult systemic lupus erythematosus: A systematic review and meta-analysis

Aim

To evaluate the diagnostic performance of the American College of Rheumatology (ACR)-1997, the Systemic Lupus International Collaborating Clinics (SLICC)-2012, and the European League against Rheumatism (EULAR)/ACR-2019 classification criteria in adult patients with systemic lupus erythematosus (SLE).

Methods

PubMed, Embase, Web of Science and Cochrane Library databases were searched for literature comparing the three classification criteria of ACR-1997, SLICC-2012 and EULAR/ACR-2019, which took clinical diagnosis as reference. Meta-analysis was used to evaluate and compare the sensitivity, specificity and diagnostic odds ratio of ACR-1997, SLICC-2012 and EULAR/ACR-2019. To assess the early diagnosis capability of the classification criteria, subgroups of patients with disease duration < 3 years and < 1 year were selected for comparison of sensitivity and specificity based on the inclusion of the original study. The sensitivity and specificity of each item in three sets of classification criteria were evaluated. In addition, the clinical and immunological characteristics of patients who did not meet the three classification criteria were compared.

Results

Nine original studies were included in the analysis, including 6404 SLE patients and 3996 controls. Results showed that the diagnostic odds ratios (95% confidence interval) of the SLICC-2012 [136.35 (114.94, 161.75)] and EULAR/ACR-2019 [187.47 (158.00, 222.42)] were higher than those of the ACR-1997 [67.53 (58.75, 77.63)]. Compared with ACR-1997[(0.86 (0.82, 0.89)], SLICC-2012[(0.96 (0.93, 0.97)] and EULAR/ACR-2019[(0.95 (0.92, 0.97)] had higher sensitivity. The specificity of the three classification criteria was similar: ACR-1997, SLICC-2012, and EULAR/ACR-2019 were 0.93 (0.89, 0.95), 0.86 (0.79, 0.91), and 0.91 (0.85, 0.95), respectively. The sensitivity of SLICC-2012 and EULAR/ACR-2019 were higher than that of ACR-1997 in early-course subgroups. Patients who did not meet ACR-1997 had more hypocomplementemia, patients who did not meet SLICC-2012 had more cutaneous lupus and photosensitivity, and patients who did not meet EULAR/ACR-2019 had more cutaneous lupus and leucopenia.

Conclusions

SLICC-2012 and EULAR/ACR-2019 have better diagnostic ability than the ACR-1997, and the sensitivity of the former two criteria is also higher than that of the latter; Moreover, the SLICC-2012 and EULAR/ACR-2019 for patients in the early stages of disease performed equally excellent.

Unusual Presentations of Systemic Lupus Erythematosus: A Narrative Review

Systemic lupus erythematosus (SLE) is a chronic systemic autoimmune disease characterized by an almost 10:1 female predominance, the presence of deleterious nuclear autoantibodies, a tendency for flare, and striking protean manifestations. Early diagnosis is associated with less damage accrual, lower costs, and improved quality of life due to timely treatment. However, early disease may not uncommonly show nonspecific presentation, a single classification criterion, or an unusual organ involvement contributing to frequent, often substantial diagnostic delays. We reviewed the literature (1982-2022) to accumulate and classify all reports of rare, atypical, and unusual presentations. These can involve almost every organ and system, and thus, present to physicians in every discipline and setting. Increasing physicians' awareness of the potential of occult SLE to appear in varied, diverse, and unexpected presentations, may encourage the inclusion of SLE in the differential. Informed history and examination focusing on systemic and joint symptoms and mucocutaneous involvement, and basic tests (focusing on leukopenia, thrombocytopenia, and proteinuria; followed by antinuclear antibodies and complement levels) will correctly diagnose most patients on presentation or within the following months and enable timely treatment.

Performances of different classification criteria for systemic lupus erythematosus in a single-center cohort from Turkey

Objective

Sensitivity and specificity of SLE classification criteria may vary in different populations and clinical settings. In this study, we aimed to compare the performances of three criteria sets/rules (1997, 2012, and 2019) in a large cohort of patients and relevant diseased controls.

Methods

The medical records of consecutive SLE patients and diseased controls were reviewed for clinical and laboratory features relevant to all sets of criteria. Criteria sets/rules were analyzed based on sensitivity, positive predictive value, specificity, and negative predictive value, using clinical diagnosis with at least 6 months of follow-up as the gold standard. A subgroup analysis was performed in ANA positive patients.

Results

A total of 393 SLE patients and 308 non-SLE diseased controls were included. Sensitivity was 78.4% for 1997 criteria and was more than 90% for both 2012 (91.9%) and 2019 (94.4%) criteria. Specificity was the highest (95.1%) for 1997 ACR criteria, 91.5% for 2012 SLICC criteria and 91.2% for 2019 EULAR/ACR criteria. When only ANA positive patients were analyzed, sensitivity of each criteria increased by 1%, 0.8%, and 2.2%, respectively. Specificity of 1997 criteria decreased by 2% and specificity of 2012 and 2019 criteria both decreased to less than 90%.

Conclusion

EULAR/ACR criteria were more sensitive than 1997 criteria and had a comparable performance with SLICC criteria. When only ANA positive patients were analyzed, the presence of false positive results (originated from patients with Sjögren’s disease and antiphospholipid syndrome mainly) decreased the specificity of both SLICC and EULAR/ACR criteria.

Utility of the ACR-1997, SLICC-2012 and EULAR/ACR-2019 classification criteria for systemic lupus erythematosus: a single-centre retrospective study

Background and aims

Several different versions of classification criteria, including the American College of Rheumatology (ACR)-1997, Systemic Lupus International Collaborating Clinics (SLICC)-2012 and European Alliance of Associations for Rheumatology (EULAR)/ACR-2019 classification criteria, have been launched in the past decades. The current study aimed to investigate the performance of these three classification criteria for diagnosing patients with SLE in a Chinese cohort.

Methods

352 patients with SLE and 385 controls with other diseases who had the detection results of ANA were enrolled into the study. Various clinical parameters were estimated, such as demographics variables, clinical characteristics and other variables related to three criteria.

Results

The current study demonstrated great diagnostic ability of the three criteria; and the receiver operating characteristic curve and the area under curve (AUC) were used to evaluate the diagnostic ability of three criteria: ACR-1997 (AUC=0.972), SLICC-2012 (AUC=0.986) and EULAR/ACR-2019 (AUC=0.983). Despite lower specificity of the SLICC-2012 and EULAR/ACR-2019 classification criteria, their sensitivity is significantly improved than ACR-1997. Of note, we also compared the median time interval between the appearance of the earliest item and fulfilment of the three sets of criteria, suggesting the SLICC-2012 and EULAR/ACR-2019 could achieve earlier diagnosis. Adjusting the thresholds of the EULAR/ACR-2019 criteria from 10 to 12, the specificity and accuracy significantly increased.

Conclusion

The SLICC-2012 and EULAR/ACR-2019 performed well in Chinese patients with SLE and showed better early diagnosis ability. In addition, by adjusting the classification threshold, the accuracy of the EULAR/ACR-2019 classification criteria was improved.

Elevated apoptosis and abnormal apoptosis signaling of regulatory T cells in patients with systemic lupus erythematosus

In systemic lupus erythematosus (SLE), immune tolerance is influenced by defects in naturally occurring T cells (Tregs). To investigate the apoptosis rate of Tregs and their suppressive activity in patients with SLE and then to recognize the genes and signaling pathways that cause Treg apoptosis. FACS was used to assess the frequency and apoptosis rates of Tregs in 48 SLE patients and 28 normal controls (NCs). Coculture of Tregs with CD4⁺CD25^-CD127^dim/- T cells was used to assess the suppressive activity of Tregs. Microarray analysis was used to generate unstimulated Tregs gene expression profiles from very high activity patients with SLE and NCs. Real-time PCR was used to confirm differential gene expression. In patients with SLE, the frequency of Tregs was substantially reduced compared to Tregs from NCs. Furthermore, Tregs from SLE patients had an elevated rate of apoptosis and a lower suppressing ability than Tregs from NCs. Tregs apoptosis was negatively associated with the total count of Tregs and positively related to disease activity. Unstimulated Tregs gene expression profiles from patients with recent-onset SLE revealed a biological response that can cause apoptosis, partially triggered by stress, DNA damage, and cytokine stimulation. The discovery of pathway-specific expression signatures is a significant step forward in understanding how Tregs defects contribute to the pathogenesis of SLE. Our findings may contribute to the development of new strategies for treating SLE based on abnormal Tregs apoptosis and restoring immune homeostasis in patients with SLE.

Persistence of Depression and Anxiety despite Short-Term Disease Activity Improvement in Patients with Systemic Lupus Erythematosus: A Single-Centre, Prospective Study

Mental disorders such as anxiety and depression are prevalent in systemic lupus erythematosus (SLE) patients, yet their association with the underlying disease activity remains uncertain and has been mostly evaluated at a cross-sectional level. To examine longitudinal trends in anxiety, depression, and lupus activity, a prospective observational study was performed on 40 adult SLE outpatients with active disease (SLE Disease Activity Index [SLEDAI]-2K ≥ 3 [excluding serology]) who received standard-of-care. Anxiety and depression were determined at baseline and 6 months by the Hospital Anxiety and Depression Scale. Treatment adherence was assessed with the Morisky Medication Adherence Scale-4. Increased anxiety (median [interquartile range] HADS-A: 11.0 [7.8]) and depression (HADS-D: 8.0 [4.8]) were found at inclusion, which remained stable and non-improving during follow-up (difference: 0.0 [4.8] and −0.5 [4.0], respectively) despite reduced SLEDAI-2K by 2.0 (4.0) (p < 0.001). Among possible baseline predictors, paid employment—but not disease activity—correlated with reduced HADS-A and HADS-D with corresponding standardized beta-coefficients of −0.35 (p = 0.017) and −0.27 (p = 0.093). Higher anxiety and depression correlated with lower treatment adherence (p = 0.041 and p = 0.088, respectively). These results indicate a high-mental disease burden in active SLE that persists despite disease control and emphasize the need to consider socioeconomic factors as part of comprehensive patient assessment.

Performance of the Revised Classification Criteria for Systemic Autoimmune Rheumatic Diseases and Their Overlap Syndromes

Objective We evaluated the performance of the revised classification criteria for assessing different systemic autoimmune rheumatic diseases and their overlap syndromes. Methods A total of 652 patients with or highly suspected of having systemic lupus erythematosus (SLE), systemic sclerosis (SSc), polymyositis (PM)/dermatomyositis (DM) or rheumatoid arthritis (RA) were included in this study. The 1997 revised American College of Rheumatology (ACR) and the 2019 European League Against Rheumatism (EULAR)/ACR criteria for SLE, the 1980 ACR and the 2013 ACR/EULAR criteria for SSc, the criteria by Bohan and Peter and the 2017 EULAR/ACR criteria for PM/DM, and the 1987 revised ACR and 2011 ACR/EULAR criteria for RA were used for disease classification. Results The old and new criteria and a clinical diagnosis were used to respectively classify 103, 106 and 105 SLE patients; 35, 47 and 58 SSc patients; 18, 23 and 33 PM/DM patients; and 297, 389 and 468 RA patients. Sensitivity increased from 82.9% to 92.4% in SLE, from 56.9% to 79.3% in SSc, from 54.5% to 66.7% in PM/DM, and from 62.6% to 80.8% in RA. SLE-SSc was the predominant type of clinical overlap syndrome, while SLE-RA was the most classifiable. Conclusion The revised classification criteria for all the diseases showed an improved sensitivity, and SLE-overlap syndrome was predominant, regardless of the criteria sets.

Predictive model of risk and severity of enteritis in systemic lupus erythematosus

INTRODUCTION

To describe the clinical and laboratory features of systemic lupus erythematosus (SLE) enteritis and to establish a predictive model of risk and severity of lupus enteritis (LE).

METHODS

Records of patients with SLE complaining about acute digestive symptoms were reviewed. The predictive nomogram for the diagnosis of LE was constructed by using R. The accuracy of the model was tested with correction curves. The receiver operating characteristic curve (ROC curve) program and a Decision curve analysis (DCA) were used for the verification of LE model. Receiver operating characteristic curve was also employed for evaluation of factors in the prediction of severity of LE.

RESULTS

During the eight year period, 46 patients were in the LE group, while 32 were in the non-LE group. Abdominal pain, emesis, D-dimer >5 μg/mL, hypo-C3, and anti-SSA positive remained statistically significant and were included into the prediction model. Area under the curve (AUC) of ROC curve in this model was 0.909. Correction curve indicated consistency between the predicted rate and actual diagnostic rates. The DCA showed that the LE model was of benefit. Forty-four patients were included in developing the prediction model of LE severity. Infection, SLE disease activity index (SLEDAI), CT score, and new CT score were validated as risk factors for LE severity. The AUC of the combined SLEDAI, infection and new CT score were 0.870.

CONCLUSION

The LE model exhibits good predictive ability to assess LE risk in SLE patients with acute digestive symptoms. The combination of SLEDAI, infection, and new CT score could improve the assessment of LE severity.

Advances in SLE classification criteria

This year, the American College of Rheumatology (ACR) 1982 classification criteria for systemic lupus erythematosus (SLE) celebrate their 40th anniversary. From this start, the quest for optimal SLE criteria has led to the 1997 ACR update, the 2012 publication of the Systemic Lupus International Collaborating Clinics (SLICC) criteria, and, in 2019, the European League Against Rheumatism (EULAR)/ACR classification criteria. The latter have since been externally validated in more than two dozen studies and have become the gold standard inclusion criterion of SLE clinical trials. This comprehensive review attempts to follow the evolving success story of SLE classification, highlighting relevant decisions and their rationale, and discussing consequences for the way SLE is defined and managed.

Population-based incidence and time to classification of systemic lupus erythematosus by three different classification criteria: a Lupus Midwest Network (LUMEN) study

OBJECTIVE

To estimate the incidence and time-to-classification of SLE by the 1997 ACR (ACR97) criteria, the SLICC criteria, and the European Alliance of Associations for Rheumatology/ACR (EULAR/ACR) criteria.

METHODS

We identified all incident SLE cases from 2000-2018 in the well-defined Olmsted County population. Clinical data included in the ACR97, SLICC and EULAR/ACR criteria were manually abstracted from medical records. All incident cases met at least one of the three classification criteria. Time-to-classification was estimated from the first documented lupus-attributable disease manifestation to the time of criteria fulfilment by each of the three definitions. Annual incidence rates were age or age/sex adjusted to the 2000 US population.

RESULTS

Of 139 incident cases there were 126 cases by the EULAR/ACR criteria, corresponding to an age/sex-adjusted incidence of 4.5 per 100 000 population (95% CI: 3.7, 5.2). The age/sex-incidence was higher than that of the SLICC criteria (113 cases; 4.0 per 100 000 [95% CI: 3.3, 4.7], P = 0.020) and the ACR97 (92 cases; 3.3 per 100 000 [95% CI: 2.6, 3.9], P < 0.001). The median time from first disease manifestation to criteria fulfilment was shorter for the EULAR/ACR criteria (29.4 months) than the ACR97 criteria (47.0 months, P < 0.001) and similar to the SLICC criteria (30.6 months, P = 0.83).

CONCLUSION

The incidence of SLE was higher by the EULAR/ACR criteria compared with the ACR97 and the SLICC criteria, and the EULAR/ACR criteria classified patients earlier that the ACR97 criteria but similar to the SLICC criteria.

Validation of the 2019 EULAR/ACR classification criteria for systemic lupus erythematosus in ANA-positive Chinese patients

Background

The aim of this study was to validate the 2019 European League Against Rheumatism/American College of Rheumatology (EULAR/ACR) classification criteria for systemic lupus erythematosus (SLE) in antinuclear antibody (ANA)-positive Chinese patients.

Methods

Medical records of all adult patients who attended the rheumatology out-patient clinics between May and September 2019 were reviewed. Patients with ever ANA positive (titre ⩾1:80) were included and evaluated for the fulfilment of the 2019 EULAR/ACR, 2012 Systemic Lupus International Collaborating Clinics (SLICC) and 1997 ACR criteria for SLE classification. The performance of these criteria in predicting a clinical diagnosis of SLE as judged by an independent panel of rheumatologists was studied and compared in different subgroups.

Results

A total of 1533 patients (88.2% women; age at first clinic attendance 45.5 ± 15.6 years) were studied and 562 patients were judged to be clinical SLE. The sensitivity and specificity of the EULAR/ACR (⩾10 points), SLICC and ACR criteria for a clinical diagnosis of SLE was 96.1%, 97.9% and 86.1%; and 85.8%, 86.3% and 94.3%, respectively. Applying the attribution rule to the non-SLE controls, the specificity of the three criteria increased to 95.0%, 92.5% and 98.8%, respectively. The specificity of the EULAR/ACR criteria was higher in male patients (97.9%), those aged >50 years (97.0%) and disease duration of ⩽3 years (97.6%). Using a cut-off of 12 points, the specificity of the EULAR/ACR criteria was further increased (96.6%) while a high sensitivity (95.0%) was maintained.

Conclusion

In Chinese patients with a positive ANA, the EULAR/ACR criteria for clinical SLE perform equally well to the SLICC criteria. Both the EULAR/ACR and SLICC are more sensitive but less specific than the ACR criteria. The specificity of all the three criteria is enhanced by applying the attribution rule to controls. The specificity of the EULAR/ACR criteria is higher in certain patient subgroups or when the cut-off score is raised.

Tailored treatment strategies and future directions in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) represents a diagnostic and therapeutic challenge for physicians due to its protean manifestations and unpredictable course. The disease may manifest as multisystemic or organ-dominant and severity at presentation may vary according to age at onset (childhood-, adult- or late-onset SLE). Different manifestations may respond variably to different immunosuppressive medications and, even within the same organ-system, the severity of inflammation may vary from mild to organ-threatening. Current "state-of-the-art" in SLE treatment aims at remission or low disease activity in all organ systems. Apart from hydroxychloroquine and glucocorticoids (which should be used with caution), the choice of the appropriate immunosuppressive agent should be individualized and depend on the prevailing manifestation, severity stratification and patient childbearing potential. In this review, we provide an overview of therapeutic options for the various organ manifestations and severity patterns of the disease, different phenotypes (such as multisystem versus organ-dominant disease), as well as specific considerations, including lupus with antiphospholipid antibodies, childhood and late-onset disease, as well as treatment options during pregnancy and lactation.

Predictors Associated with Adverse Pregnancy Outcomes in a Cohort of Women with Systematic Lupus Erythematosus from Romania-An Observational Study (Stage 2)

Background: Pregnancy in women with systemic lupus erythematosus (SLE) is accompanied by adverse pregnancy outcomes (APOs). We aimed to investigate the association between clinical, sonographic, and laboratory parameters and APOs (preeclampsia, intrauterine growth restriction, premature birth, and maternal mortality). Methods: This observational retrospective study included all pregnancies in women with SLE who attended two tertiary maternity hospitals from Romania between January 2013 and December 2020. Clinical, sonographic, and laboratory variables were examined. Bivariate associations of APO status and each predictor variable were evaluated, and significant predictors were further included in a classification model based on discriminant analysis. Results: Predictors of APOs included BMI > 25 kg/m2, personal history of lupus nephritis or chronic hypertension, proteinuria, low C3, SLE Disease Activity Index 2000 (SLEDAI-2k score ≥ 4 and physician’s global-assessment (PGA) score ≥ 1 throughout pregnancy, increased mean uterine arteries pulsatility index in the first and second trimesters, cerebroplacental ratio < 1 in the second and third trimesters, and small fetal abdominal circumference in the third trimester. Glucocorticoids, methyldopa, and aspirin use appeared to be protective against APOs. Conclusions: This study provides a comprehensive analysis of the most important predictors for APOs in pregnant patients with SLE, which could constitute a basis for further research.

Animal models of systemic lupus erythematosus and their applications in drug discovery

INTRODUCTION

Systemic lupus erythematosus (SLE) is a multisystem autoimmune disease with substantial phenotypic heterogeneity. Currently, our understanding of the pathogenesis is still limited, and as a result, specific and efficacious therapies are lacking. Various mouse models have been established to serve as powerful tools that will promote a better understanding of the disease and the ability to test novel drugs before clinical application.

AREAS COVERED

The authors review the existing mouse models of SLE in terms of pathogenesis and manifestations, as well as their applications in drug discovery and development. The areas of focus include promising novel therapeutics that could benefit patients in the future and the contribution of mouse models used in preclinical studies.

EXPERT OPINION

Given the diversity of SLE mouse models with different characteristics, researchers must select a suitable model based on the mechanism involved. The use of multiple models is needed for drug testing studies to evaluate drug efficacy on different genetic backgrounds and other mechanisms to provide a reference for clinical trials.

Systemic lupus erythematosus as a genetic disease

Systemic lupus erythematosus is the prototypical systemic autoimmune disease, as it is characterized both by protean multi-organ system manifestations and by the uniform presence of pathogenic autoantibodies directed against components of the nucleus. Prior to the modern genetic era, the diverse clinical manifestations of SLE suggested to many that SLE patients were unlikely to share a common genetic risk basis. However, modern genetic studies have revealed that SLE usually arises when an environmental exposure occurs in an individual with a collection of genetic risk variants passing a liability threshold. Here, we summarize the current state of the field aimed at: (1) understanding the genetic architecture of this complex disease, (2) synthesizing how this genetic risk architecture impacts cellular and molecular disease pathophysiology, (3) providing illustrative examples that highlight the rich complexity of the pathobiology of this prototypical autoimmune disease and (4) communicating this complex etiopathogenesis to patients.

First Diagnosis of Systemic Lupus Erythematosus in Hospitalized Patients: Clinical Phenotypes and Pitfalls for the Non-Specialist

BACKGROUND

Prompt recognition of systemic lupus erythematosus (SLE) in hospitalized patients presenting with severe disease is essential to initiate treatment. We sought to characterize the phenotype of hospitalized patients with new-onset SLE and estimate potential diagnostic delays.

METHODS

An observational study of 855 patients ("Attikon" SLE cohort). Clinical phenotype was categorized according to the leading manifestation that led to hospitalization. Disease features, time to diagnosis, classification criteria, and the SLE Risk Probability Index (SLERPI) were recorded for each patient.

RESULTS

There were 191 patients (22.3% of the total cohort) hospitalized due to manifestations eventually attributed to SLE. Main causes of admission were neuropsychiatric syndromes (21.4%), cytopenias (17.8%), nephritis (17.2%), and thrombotic events (16.2%). Although 79.5% of patients were diagnosed within 3 months from hospitalization, in 39 patients diagnosis was delayed, particularly in those with hematological manifestations. At hospitalization, a SLERPI >7 (indicating high probability for SLE) was found in 87.4% of patients. Patients missed by the SLERPI had fever, thrombotic or neuropsychiatric manifestations not included in the algorithm. Lowering the SLERPI threshold to 5 in patients with fever or thrombotic events increased the diagnostic rate from 88.8% to 97.9% in this subgroup, while inclusion of all neuropsychiatric events yielded no additional diagnostic value.

CONCLUSION

One in five patients with new-onset SLE manifest disease presentations required hospitalization. Although early diagnosis was achieved in the majority of cases, in approximately 20%, diagnosis was delayed. A lower SLERPI cut-off (≥5) in patients with fever or thrombosis could enhance early diagnosis.

Performance of the systemic lupus erythematosus risk probability index in a cohort of undifferentiated connective tissue disease

OBJECTIVES

We sought to evaluate the performance of the systemic lupus erythematosus (SLE) Risk Probability Index (SLERPI) for identification of SLE in a large cohort of patients with undifferentiated connective tissue disease (UCTD).

METHODS

The SLERPI was applied in a cohort of patients who met classification criteria for UCTD and did not fulfill any classification criteria for other defined CTD including SLE. Patients with a SLERPI score of > 7 were "diagnosed" as SLE. Patients diagnosed with SLE and those not, were compared in terms of disease characteristics and index parameters.

RESULTS

A total of 422 patients with UCTD were included in the study. Median (IQR) SLERPI was 4.25 (2.5) points, while 39 (9.2%) patients had a SLERPI score >7 and were diagnosed as SLE. Patients with younger age (p = 0.026) and presence of malar rash (p < 0.0001), mucosal ulcer (p < 0.0001), alopecia (p < 0.0001), ANA positivity (p < 0.0001), low C3 and C4 (p = 0.002), proteinuria>500 mg/24 hours (p = 0.001), thrombocytopenia (p = 0.009) or autoimmune haemolytic anaemia (p < 0.0001) were more likely to fulfill criteria for SLE by the SLERPI.

CONCLUSION

SLERPI enabled a significant proportion of patients to be identified as SLE in our UCTD cohort. This new probability index may be useful for early identification of SLE among patients with signs of CTD without fulfilling any definite criteria set.

Differentiating between UCTD and early-stage SLE: from definitions to clinical approach

Systemic lupus erythematosus (SLE) is an autoimmune disease with heterogeneous clinical manifestations that can potentially affect every organ and system. SLE is usually identified on the basis of clinical or serological manifestations; however, some individuals can present with signs and symptoms that are consistent with SLE but are not sufficient for a definite diagnosis. Disease in these individuals can either progress over time to definite SLE or remain stable, in which case their disease is often described as intermediate, possible or probable SLE. Alternatively, such individuals might have undifferentiated connective tissue disease (UCTD). Being able to differentiate between those with stable UCTD and those with SLE at an early stage is important to avoid irreversible target-organ damage from occurring. This Review provides insight into existing and evolving perceptions of the early stages of SLE, including clinical and mechanistic considerations, as well as potential paths towards early identification and intervention. Further research into the earliest phases of SLE will be important for the development of targeted diagnostic approaches and biomarkers for the identification of individuals with early disease who are likely to progress to definite SLE.

Performance of the 2019 European League Against Rheumatism/American College of Rheumatology classification criteria for systemic lupus erythematosus in a multiethnic Malaysian cohort

AIM

To evaluate the performance of the 2019 European League Against Rheumatism/American College of Rheumatology (EULAR/ACR) classification criteria for systemic lupus erythematosus (SLE) in a multi-ethnic Malaysian cohort and to compare it against the Systemic Lupus International Collaborating Clinics (SLICC) 2012 and ACR 1997 criteria.

METHOD

We conducted a retrospective observational study of 205 patients with a diagnosis of SLE and 100 controls who formed the validation cohort. The sensitivity and specificity of the three classification criteria were evaluated and a further sub-analysis was performed in patients with early disease and among the various ethnicities.

RESULTS

The sensitivities and specificities of the three classification criteria are as follows: EULAR/ACR (90.8%; 94%), SLICC 2012 (96.1%; 94%), and ACR 1997 (82%; 96%). Among patients with early disease, the sensitivity of the SLICC 2012 was higher than that of EULAR/ACR and ACR 1997 (98% vs 94% and 86%); however, the specificity of EULAR/ACR and ACR 1997 were similar (95.2%) and higher than the SLICC 2012 (93.5%). The SLICC 2012 had higher sensitivity than that of the EULAR/ACR among the Malays (94% vs 90%), Chinese (98% vs 90%), and Indians (100% vs 95%). The specificity of the EULAR/ACR and SLICC 2012 were similar in the Malay and Chinese (93.3% each, and 92% vs 94.6%).

CONCLUSION

The EULAR/ACR performed well in our cohort. The EULAR/ACR and SLICC 2012 showed higher sensitivity than the ACR 1997, and the EULAR/ACR showed similar specificity to the ACR 1997 and SLICC 2012 overall, in early disease, and across the different ethnicities.

Impact of the 2019 European Alliance of Associations for Rheumatology/American College of Rheumatology Classification Criteria for Systemic Lupus Erythematosus in a Multicenter Cohort Study of 133 Women With Undifferentiated Connective Tissue Disease

OBJECTIVE

We aimed to investigate the impact of applying the 2019 European Alliance of Associations for Rheumatology (EULAR)/American College of Rheumatology (ACR) classification criteria for systemic lupus erythematosus (SLE) in a previously described cohort of women with undifferentiated connective tissue disease (UCTD).

METHODS

This study included 133 women with UCTD. At the time of inclusion into the study, none of the patients met any classification criteria for other defined systemic connective tissue disease.

RESULTS

When applying the 2019 EULAR/ACR classification criteria to the cohort, 22 patients (17%) fulfilled the classification criteria for SLE. Patients classified as having SLE had significantly higher frequencies of mucocutaneous manifestations (23% versus 5%; P = 0.007), arthritis (59% versus 17%; P < 0.001), isolated urine abnormalities (18% versus 1%; P < 0.001), and highly specific antibodies (50% versus 15%; P < 0.001) compared to the other patients with UCTD. At follow-up, these patients were statistically significantly more likely to also meet the 1997 ACR revised SLE criteria and the Systemic Lupus International Collaborating Clinics (SLICC) criteria (18.2% versus 1.8%; P < 0.001) compared to the other UCTD patients. Patients who were diagnosed as having SLE according to the ACR 1997 update of the SLE revised criteria and the SLICC criteria during the follow-up scored higher on outcome measures when classified as having SLE according to the new 2019 EULAR/ACR classification criteria when compared to the other patients with UCTD (mean ± SD score 8.3 ± 3.7 versus 4.5 ± 4; P < 0.05).

CONCLUSION

When applying the 2019 EULAR/ACR criteria for SLE in a cohort of patients with UCTD, we observed that in up to 17% of cases the original classification could be challenged. New implementation will help to identify earlier patients at higher risk of developing more severe CTD manifestations.

Comparison of the sensitivity of the EULAR / ACR 2019 and SLICC 2012 classification criteria in a Colombian population with systemic lupus erythematosus

BACKGROUND

/Objective: Systemic lupus erythematosus (SLE) is a multisystem autoimmune disease with a wide range of clinical manifestations. The latest classification criteria, EULAR/ACR 2019, have not been validated in a Latin American population of Amerindian ancestry. The objective of this study is to compare the sensitivity of the EULAR/ACR 2019 and SLICC 2012 classification criteria in a group of SLE patients with the above ancestry.

METHODS

A cross-sectional study was done. Data were obtained from the review of medical records of patients who met the inclusion criteria. The overall sensitivity of the criteria was calculated and compared to each other using the McNemar test.

RESULTS

146 medical records of patients from two referral centers were included. There were no differences in the sensitivity of the EULAR/ACR and SLICC 2012 criteria (84.9% versus 85.6% p = 0.79) nor were differences found when the groups based on disease duration were compared: less than 5 years (91.0% versus 92.5% p = 0.70), between 5 and 10 years (82.8% versus 82.8% p = 1), and 10 years or more (76.7% versus 76.7% p = 1). However, SLICC 2012 criteria was found to better classify patients with a less than 5-year disease duration compared to those with 10-year duration or more (92.5% versus 76.4% p = 0.024).

CONCLUSIONS

There are no statistically significant differences between the EULAR/ACR and SLICC 2012 criteria in the population studied. Nor were differences found when evaluating them by age at diagnosis and duration of the disease except when the group with less than 5 years of duration was compared to those with 10 years or more using the SLICC 2012 criteria.

Imbalanced MMP-3 and MMP-12 serum levels in systemic lupus erythematosus patients with Jaccoud's arthropathy and a distinctive MRI pattern

OBJECTIVE

Metalloproteinase (MMP)-3 and MMP-12 are proteolytic enzymes especially implicated in joint inflammation. This study aims to evaluate their association with arthritis features and hand MRI abnormalities in patients with SLE.

METHODS

Fifty SLE patients, with a mean (s.d.) age of 48.1 (14.6) years were tested for MMP-3 and MMP-12 serum levels, then further classified according to the presence of X-ray erosions and joint deformities. Eighteen RA patients aged 47.9 (11.8) and 14 healthy people aged 46.0 (11.0) were enrolled as control groups. A subgroup of 28 SLE patients underwent a dominant-hand MRI; the detected changes were classified and semi-quantitatively scored as capsular swelling, synovitis, edematous or proliferative tenosynovitis, bone oedema, bone erosions. Statistical analysis was performed using multiple regression models.

RESULTS

MMP-3 were significantly higher in patients with Jaccoud's arthropathy (JA) (22.1 ng/ml, P < 0.05) and independently associated with hsCRP serum levels (B-coeff 0.50; r = 0.30; P < 0.05). MMP-12 serum levels were significantly lower in patients with JA (0.18 ng/ml, P < 0.05) and inversely associated with the prednisone daily dose (B-coeff -0.03; r = -0.44; P < 0.01). Capsular swelling and edematous tenosynovitis, the most prevalent hand MRI changes in patients with JA, associated with higher MMP-3 (B-coeff 0.12; r = 0.66; P < 0.01 and B-coeff 0.08; r = 0.59; P < 0.01, respectively) and lower MMP-12 serum levels (B-coeff -7.4; r = -0.50; P < 0.05 and B-coeff -5.2; r = -0.44; P = 0.05, respectively).

CONCLUSION

Imbalanced MMP-3 and MMP-12 serum levels are influenced by inflammation and glucocorticoids in SLE patients and associated with JA and distinctive hand MRI changes.

Demyelination with autoimmune features: a distinct clinical entity? Results from a longitudinal cohort

OBJECTIVE

CNS demyelinating syndromes occurring in the context of SLE may represent a manifestation of neuropsychiatric lupus, or an overlap of SLE and multiple sclerosis (MS). We evaluated prospectively patients presenting with demyelinating syndrome for clinical and serological evidence of SLE and characterized the evolution of their clinical syndrome to a defined disease.

METHODS

Patients with CNS demyelinating syndromes not fulfilling the criteria for MS were evaluated in a rheumatology unit for features of SLE and followed longitudinally (enrolment period 2016-20). Clinical, laboratory and neuroimaging data were recorded at every visit, following multidisciplinary evaluation. At end of follow-up, patients were assessed for their final neurological and rheumatological diagnosis, and classified accordingly.

RESULTS

A total of 79 patients were included in the study [91.1% female, mean (s.d.) age at first demyelinating episode 38.4 (10.3) years, median (interquartile range) observation period 39 (57) months]. At last follow-up, 38 patients (48.1%) had evolved into MS. Of the remaining patients, 7 (17.1%) had SLE, while 34 (82.9%) had features of systemic autoimmunity without fulfilling classification criteria for SLE. The most common rheumatological features of these patients were inflammatory arthritis (73.5%), acute cutaneous lupus (47.1%) and positive ANA (72.1%). Importantly, these patients were less likely to have elevated IgG index (odds ratio 0.11, 95% CI 0.04, 0.32) and positive oligoclonal bands (odds ratio 0.21, 95% CI 0.08, 0.55).

CONCLUSION

A significant number of patients with demyelination do not fulfill criteria for either MS or SLE at follow-up. These patients exhibit lupus-like autoimmune features and may represent a distinct entity, 'demyelination with autoimmune features'.

Avoiding misclassification of thrombotic primary antiphospholipid syndrome as systemic lupus erythematosus (SLE): What are the best-performing SLE classification criteria?

BACKGROUND

Systemic lupus erythematosus (SLE) and Primary Antiphospholipid Syndrome (PAPS) overlap clinical and immunological features. Therefore, misclassification of PAPS patients as SLE is a concern. The ACR/EULAR 2019 SLE classification has never been studied in PAPS.

OBJECTIVE

To verify if the ACR/EULAR 2019 SLE classification can correctly classify a PAPS patient as not having SLE and compare its performance with the SLICC 2012 SLE classification. Methods: One-hundred thrombotic PAPS patients who fulfilled the Sidney criteria were consecutively screened and those who attended the inclusion criteria were submitted to ACR/EULAR 2019 and SLICC 2012 classifications.

RESULTS

Sixty-seven PAPS patients were included in this study. The majority was female (89.6%) with median age at study inclusion of 45 years (35-53) and median PAPS disease duration of 13 years (8-19). PAPS correct classification was observed more often with ACR/EULAR 2019 than SLICC 2021 criteria (94.0% vs. 64.2%; p < 0.001). The 4 misclassified patients in ACR/EULAR 2019 were also misclassified in SLICC 2012. The comparison of misclassified patients to those correctly not classified as SLE resulted, for both criteria, in higher frequencies of hematological domain [ACR/EULAR 2019 (100% vs. 28.6%, p = 0.010) and SLICC 2012 (95.8% vs. 11.6%, p < 0.001)]. Further analysis of hematological manifestations revealed that for the ACR/EULAR 2019 leukopenia (100% vs. 22.2%, p = 0.004) and for the SLICC 2012 leukopenia/lymphopenia (91.7% vs. 7%, p < 0.001) were more frequent in misclassified group. Proteinuria (20.8% vs. 0%, p = 0.004) and low complement (45.8% vs. 20.9%, p = 0.033) were also more often observed in the incorrectly SLICC 2012 classified patients.

CONCLUSION

ACR/EULAR 2019 had high accuracy for distinguishing PAPS from SLE, whereas the SLICC 2012 incorrectly classified more than one third of the PAPS patients as having SLE.