Antiplatelet effects of hydroxychloroquine in patients with systemic lupus erythematosus evaluated by the total thrombus-formation analysis system (T-TAS).

OBJECTIVES: Hydroxychloroquine (HCQ) has been shown to reduce thrombotic events in patients with SLE. However, the antiplatelet effects of HCQ are only supported by the platelet aggregation assay, which is a non-physiological test. The total thrombus-formation analysis system (T-TAS) is a microchip-based flow chamber system that mimics physiological conditions and allows for the quantitative analysis of thrombogenicity. The present study investigated the antiplatelet effects of HCQ using T-TAS. METHODS: This was a single-centre cross-sectional study on 57 patients with SLE. We measured the area under the pressure curve for 10 min (PL-AUC10) and the time to 10 kPa (T10) in patients with SLE using T-TAS and examined their relationships with the use of HCQ. PL-AUC10 and platelet aggregation were also measured at several HCQ concentrations using blood samples from healthy donors. RESULTS: PL-AUC10 was significantly lower in the HCQ/real body weight (RBW) ≥5 mg/kg group than in the <5 mg/kg group, while T10 was similar, indicating that HCQ inhibited overall thrombus formation rather than the initiation of thrombus formation. The antiplatelet effects of HCQ were initially detected at HCQ/RBW of approximately 4 mg/kg and reached a plateau at around 5.5 mg/kg. The administration of HCQ/RBW >4.6 mg/kg clearly exerted antiplatelet effects. Additionally, HCQ inhibited thrombus formation in T-TAS and the platelet aggregation response to epinephrine in a dose-dependent manner. CONCLUSIONS: We demonstrated the antiplatelet effects of HCQ under conditions simulating the physiological environment by using T-TAS and identified the range of doses at which HCQ exerted antiplatelet effects.

Outcome clusters and their stability over 1 year in patients with SLE: self-reported and performance-based cognitive function, disease activity, mood and health-related quality of life.

OBJECTIVE: To determine if self-reported fatigue, anxiety, depression, cognitive difficulties, health-related quality of life, disease activity scores and neuropsychological battery (NB) cluster into distinct groups in patients with SLE based on symptom intensity and if they change at 1-year follow-up. METHODS: This is a retrospective analysis of consecutive consenting patients, followed at a single centre. Patients completed a comprehensive NB, the Beck Anxiety Inventory, Beck Depression Inventory, Fatigue Severity Scale, Short-Form Health Survey Physical Component Summary and Mental Component Summary scores and the Perceived Deficits Questionnaire. Disease activity was assessed by Systemic Lupus Erythematosus Disease Activity Index 2000. Ward's method was used for clustering and principal component analysis was used to visualise the number of clusters. Stability at 1 year was assessed with kappa statistic. RESULTS: Among 142 patients, three clusters were found: cluster 1 had mild symptom intensity, cluster 2 had moderate symptom intensity and cluster 3 had severe symptom intensity. At 1-year follow-up, 49% of patients remained in their baseline cluster. The mild cluster had the highest stability (77% of patients stayed in the same cluster), followed by the severe cluster (51%), and moderate cluster had the lowest stability (3%). A minority of patients from mild cluster moved to severe cluster (19%). In severe cluster, a larger number moved to moderate cluster (40%) and fewer to mild cluster (9%). CONCLUSION: Three distinct clusters of symptom intensity were documented in patients with SLE in association with cognitive function. There was a lower tendency for patients in the mild and severe clusters to move but not moderate cluster over the course of a year. This may demonstrate an opportunity for intervention to have moderate cluster patients move to mild cluster instead of moving to severe cluster. Further studies are necessary to assess factors that affect movement into moderate cluster.

Real-world effectiveness of belimumab in patients with lupus in China: RELIABLE observational cohort study protocol.

INTRODUCTION: The efficacy of belimumab in SLE has been demonstrated in randomised clinical trials, and its real-world effectiveness has been shown in studies in several countries. While belimumab was approved for treating SLE in China in 2019, data on its benefit in clinical practice are limited. This study will evaluate belimumab's effectiveness in China, using practical clinical measures, such as Lupus Low Disease Activity State (LLDAS), to add to the body of real-world evidence. METHODS AND ANALYSIS: The Real-world Effectiveness of beLImumAB in patients with systemic Lupus Erythematosus in China (RELIABLE) is an ambidirectional, observational descriptive cohort study across approximately 15 centres in China. Adults with SLE newly initiating belimumab with ≥1 measure of all five LLDAS components (SLE Disease Activity Index-2000; no new lupus disease activity; Physician Global Assessment; prednisolone-equivalent dose; immunosuppressants/biologics use) in the 3 months preceding belimumab initiation (index date) will be eligible and retrospectively and/or prospectively enrolled, depending on data availability. The retrospective follow-up will be ≤6 months, and retrospective and prospective patients will have a maximum 24-month follow-up. The primary objectives will be to describe the proportion of patients achieving LLDAS at 12 and 24 months post-index. The key secondary objective will be to describe the proportion of patients achieving LLDAS and each component at 3, 6, 9 and 18 months post-index. All data will be analysed descriptively; a statistical estimand will be applied to account for intercurrent events expected in a real-world setting. ETHICS AND DISSEMINATION: This study will comply with all applicable laws regarding patient privacy; institutional review board approval will be obtained before the study commencement. CONCLUSIONS: This study will evaluate belimumab's effectiveness in patients with SLE initiating belimumab in clinical practice in China. Using LLDAS will provide clinicians with valuable insights into the impact of belimumab on the treat-to-target strategy with a relevant measure that can be repeated across the clinical practice.

Curcumin attenuates lupus nephritis by inhibiting neutrophil migration via PI3K/AKT/NF-κB signalling pathway.

OBJECTIVE: To investigate the role of curcumin in the treatment of lupus nephritis (LN) by inhibiting the migration of neutrophils and the underlying mechanism involved. METHODS: Two lupus mouse models, MRL/lpr mice and R848-treated mice, were treated with 50 mg/kg curcumin by intraperitoneal injection. H&E and Masson staining were used to estimate histopathological changes in the kidney. Immunofluorescence was used to assess the deposition of immune complexes. The expression of inflammatory factors was detected by enzyme-linked immunosorbent assay (ELISA) and real-time reverse transcription polymerase reaction (RT-PCR), and the protein expression was detected by western blotting. RESULTS: We revealed the remarkable potential of curcumin in improving inflammatory conditions in both MRL/lpr mice and R848-induced lupus mice. Curcumin effectively decelerates the progression of inflammation and diminishes the infiltration of neutrophils and their release of pivotal inflammatory factors, thereby reducing inflammation in renal tissues. Mechanistically, curcumin significantly inhibits the expression of p-PI3K, p-AKT and p-NF-κB, which are upregulated by interleukin-8 to induce neutrophil migration and renal inflammation, thereby reducing neutrophil migration and the release of inflammatory factors. CONCLUSION: Curcumin significantly inhibits the recruitment of neutrophils and the release of proinflammatory factors in the kidney by inhibiting the PI3K/AKT/NF-κB signalling pathway, providing new therapeutic targets and medication strategies for the treatment of LN.

Value of SLE-DAS in assessing disease activity in patients with systemic lupus erythematosus: a single-centre retrospective study.

OBJECTIVES: This study aimed to evaluate the clinical value of the Systemic Lupus Erythematosus Disease Activity Score (SLE-DAS) for assessing disease activity in patients with SLE. METHODS: Clinical data were collected from patients with SLE who were admitted at the Second Affiliated Hospital of Soochow University from January 2009 to December 2022. The glucocorticoid dose grading was used as the gold standard for disease activity assessment in SLE. The SLE-DAS value was calculated, and the SLE disease activity status was graded based on the SLE-DAS value. Another scoring criterion, the SLE Disease Activity Index 2000 (SLEDAI 2000), served as a control. Spearman correlation analysis was used to calculate the correlation between the scoring criteria and other variables. RESULTS: The analysis included 396 patients with SLE. A strong correlation was found between SLE-DAS and SLEDAI 2000 (ρ=0.709, 95% CI 0.648 to 0.766, p<0.001), with median SLE-DAS and SLEDAI 2000 scores of 15.32 (7.90 to 24.45) and 13 (8 to 19), respectively. Compared with the SLEDAI 2000 value, the SLE-DAS value correlated better with glucocorticoid dose grading (ρ=0.434 vs 0.518), gammaglobulin use (ρ=0.170 vs 0.318) and immunosuppressant use (ρ=0.122 vs 0.221). A moderate correlation based on disease activity grading was found between SLE-DAS and glucocorticoid dose grading (ρ=0.441), whereas a mild correlation was observed between SLEDAI 2000 and glucocorticoid dose grading (ρ=0.325). Additionally, SLE-DAS revealed a positive correlation with severe thrombocytopenia, cardiac involvement and pulmonary involvement but not SLEDAI 2000. CONCLUSION: Compared with SLEDAI 2000, SLE-DAS may provide a more accurate disease activity assessment in patients with SLE, especially those with severe thrombocytopenia and cardiopulmonary involvement.

Multidisciplinary re-evaluation of neuropsychiatric events to confirm the neuropsychiatric lupus diagnosis at an Indonesian tertiary hospital.

OBJECTIVE: Neuropsychiatric SLE (NPSLE) has a broad spectrum and to date, there is no gold-standard biomarker. The diagnosis relies on clinical assessment, supporting examinations and exclusion of other possible aetiologies. One method that can be used to establish NPSLE is to conduct a re-evaluation by involving several fields of medical science. This study aims to reassess SLE cases with neuropsychiatric (NP) manifestations through multidisciplinary re-evaluation and determine the final diagnosis of NPSLE or non-NPSLE. METHODS: This retrospective cross-sectional study used medical record data from patients with SLE with NP manifestations. Inclusion criteria included patients diagnosed with SLE, who had clinical manifestations of NP and were >18 years old. Multidisciplinary re-evaluation was conducted and agreed upon the diagnosis of NPSLE or non-NPSLE. RESULTS: We included 94 subjects with a total of 132 NP events consisting of 69 NPSLE and 63 non-NPSLE. After re-evaluating NPSLE events, 33.3% were still concluded to be NPSLE. Meanwhile, from the non-NPSLE group, 22.2% were then declared as NPSLE. There were no significant differences in demographic characteristics between the NPSLE and non-NPSLE groups. The proportion of NP events in both groups was almost the same except for cerebrovascular disease manifestations which were more common in the NPSLE group. Higher Mexican SLE Disease Activity Index scores with (p<0.001) or without NP (p=0.02) were observed in the NPSLE group compared with the non-NPSLE group, as well as higher proportion of active disease (p=0.03), higher anti-double-stranded DNA titres (p<0.001) and lower values of C3 (p=0.018) and C4 (p=0.001). CONCLUSIONS: Multidisciplinary re-evaluation can be used as a method to confirm the diagnosis of NPSLE. There is a tendency for overdiagnosis of NPSLE when clinicians are faced with NP events in patients with SLE. Complete clinical and supporting data are needed to determine the final diagnosis of NPSLE.

A cross sectional study assessing steatotic liver disease in patients with systemic lupus erythematosus.

Patients with immune-mediated inflammatory diseases are prone to steatotic liver disease (SLD), which has been observed in patients with psoriasis and hidradenitis suppurativa. We aimed to assess whether systemic lupus erythematosus (SLE) was associated with SLD and to define factors associated with SLD in SLE. This was a cross-sectional study, we included 106 consecutive patients with SLE who were seen in the rheumatology clinic between June 2021 and March 2022 and we chose two sex-paired controls for each SLE. All the participants underwent FibroScan and anthropometric assessments. SLD was defined as a controlled attenuation parameter ≥ 275dB/m. Prevalence of SLD was lower in patients with SLE (21.7% vs 41.5%, p < 0.001). Patients with SLE and SLD had a lower frequency of hydroxychloroquine use (65% vs 84%, p = 0.04), and higher C3 levels [123mg/dl (IQR 102-136) vs 99mg/dl (IQR 78-121), p = 0.004]. Factors associated with SLD in SLE were body mass index (BMI), waist circumference, glucose, and C3; hydroxychloroquine use was a protective factor. On univariate analysis, SLE was associated with a reduced risk of SLD (OR 0.39, 95%CI 0.23-0.67); however, after adjusting for age, BMI, waist, glucose, triglycerides, high-density cholesterol, low-density cholesterol, leukocytes, and hydroxychloroquine, it was no longer associated (OR 0.43, 95%CI 0.10-1.91). In conclusion, the prevalence of SLD in patients with SLE was not higher than that in the general population, and SLE was not associated with SLD. The factors associated with SLD were anthropometric data, glucose, hydroxychloroquine, and C3 levels.

Inhibition of receptor interacting protein kinase-1 (RIPK1) in the treatment of murine lupus.

OBJECTIVE: Systemic lupus erythematosus (SLE) is a type of autoimmune disease that involves multiple organs involved as well as cytokine dysregulation. The treatment of SLE is still challenging due to the side effects of the different drugs used. Receptor-interacting protein kinase 1 (RIPK1) is a kinase involved in T cell homeostasis and autoinflammation. Although clinical trials have shown that RIPK1 inhibition exhibits significant efficacy in different autoimmune diseases, its role in SLE remains unclear. METHODS: MRL/lpr lupus-prone mice received RIPK1 inhibitor ZJU37 or vehicle intraperitoneally for 10 weeks. A BM12-induced chronic graft-versus-host-disease (cGVHD) lupus-like model was introduced in RIPK1 D138N mice or C57BL/6 mice. Nephritis, serum autoantibody levels, dysregulation of adaptive immune response and cytokines were compared in treated and untreated mice. RESULTS: ZJU37 alleviated the clinical features of the MRL/lpr mice including nephritis and anti-dsDNA antibody production. In addition, ZJU37 treatment reduced the proportion of double-negative T cells in the spleen and the cytokines of TNFα, IFN-γ, IL-6, IL-17 and IL-1ß in the serum. Moreover, RIPK1 D138N mice were able to prevent the cGVHD lupus-like model from SLE attack, manifesting as anti-dsDNA antibody production, the proliferation of germinal centre B cells, plasma cells, and T follicular helper cells as well as IgG and C3 deposits in kidneys. CONCLUSION: RIPK1 inhibition has a protective effect in the mouse model of SLE and can potentially become a new therapeutic target for SLE in humans.

Haematopoietic stem cell-derived immune cells have reduced X chromosome inactivation skewing in systemic lupus erythematosus.

OBJECTIVES: Systemic lupus erythematosus (SLE) shows a marked female bias in prevalence. X chromosome inactivation (XCI) is the mechanism which randomly silences one X chromosome to equalise gene expression between 46, XX females and 46, XY males. Though XCI is expected to result in a random pattern of mosaicism across tissues, some females display a significantly skewed ratio in immune cells, termed XCI-skew. We tested whether XCI was abnormal in females with SLE and hence contributes to sexual dimorphism. METHODS: We assayed XCI in whole blood DNA in 181 female SLE cases, 796 female healthy controls and 10 twin pairs discordant for SLE. Using regression modelling and intra-twin comparisons, we assessed the effect of SLE on XCI and combined clinical, cellular and genetic data via a polygenic score to explore underlying mechanisms. RESULTS: Accommodating the powerful confounder of age, XCI-skew was reduced in females with SLE compared with controls (p=1.3×10-5), with the greatest effect seen in those with more severe disease. Applying an XCI threshold of >80%, we observed XCI-skew in 6.6% of SLE cases compared with 22% of controls. This difference was not explained by differential white cell counts, medication or genetic susceptibility to SLE. Instead, XCI-skew correlated with a biomarker for type I interferon-regulated gene expression. CONCLUSIONS: These results refute current views on XCI-skew in autoimmunity and suggest, in lupus, XCI patterns of immune cells reflect the impact of disease state, specifically interferon signalling, on the haematopoietic stem cells from which they derive.

SF-36v2 and FACIT-Fatigue quality of life improvements with organ-specific SELENA-SLEDAI response and belimumab treatment in patients with systemic lupus erythematosus.

OBJECTIVE: Explore organ-specific SLE burden by assessing health-related quality of life (HRQoL) and fatigue changes associated with Safety of Estrogens in Lupus Erythematosus National Assessment-Systemic Lupus Erythematosus Disease Activity Index (SELENA-SLEDAI) organ system response (score improvement) and belimumab treatment. METHODS: Data from four phase III belimumab trials were pooled for post hoc analysis (GSK Study 217382): BLISS-52 (NCT00424476), BLISS-76 (NCT00410384), BLISS-SC (NCT01484496) and EMBRACE (NCT01632241). Patients with baseline organ system involvement were classed as organ system responders if SELENA-SLEDAI scores for that organ system decreased at any post-baseline visit. HRQoL (36-Item Short Form Health Survey version 2 (SF-36v2)) and fatigue (Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-Fatigue)) changes over 52 weeks were compared between organ system responders and non-responders, and separately between belimumab versus placebo treatment arms among organ system responders. Group-level differences were compared using analysis of variance; differences were interpreted using published group-level minimal important difference (MID). RESULTS: In these post hoc analyses, musculoskeletal and mucocutaneous organ system responders had greater SF-36v2 improvements than non-responders across most SF-36v2 domains, but differences were largely MID), with FACIT-Fatigue also improving >MID for renal responders receiving belimumab. CONCLUSIONS: SLE disease burden differs with the organ system(s) involved. While these analyses are limited by mutual inclusivity of organ system groupings, differing patient numbers between groups and small numbers in some groups, they suggest that mucocutaneous and musculoskeletal organ system response improves SF-36v2 domain scores; cardiovascular and respiratory organ system response may meaningfully improve fatigue; and belimumab may offer additional HRQoL or fatigue benefits beyond standard therapy for musculoskeletal and renal responders.

Advances in the pharmacological management of systemic lupus erythematosus.

INTRODUCTION: Despite setbacks in clinical trials for systemic lupus erythematosus (SLE), three drugs have been approved for SLE and lupus nephritis (LN) treatment in the past decade. Several ongoing clinical trials, some viewed optimistically by the scientific community, underscore the evolving landscape. Emerging clinical data have established specific therapeutic targets in routine clinical practice for treating SLE, aiming to improve long-term outcomes. AREAS COVERED: Research related to treatment of SLE and LN is discussed, focusing on randomized clinical trials during the last 5 years and recommendations for the management of SLE published by the European Alliance of Associations for Rheumatology (EULAR), American College of Rheumatology (ACR), Asia Pacific League of Associations for Rheumatology (APLAR), and Pan-American League of Associations of Rheumatology (PANLAR). EXPERT OPINION: The landscape of SLE and LN treatments is evolving, as new drugs and combination treatment approaches redefine the traditional concepts of induction and maintenance treatment phases. As the therapeutic armamentarium in SLE continues to expand, the research focus is shifting from the imperative for new therapies to advancing our understanding of optimal treatment selection for individual patients, steering toward precision medicine strategies.

The role of DNA in the pathogenesis of SLE: DNA as a molecular chameleon.

Systemic lupus erythematosus (SLE) is a prototypic autoimmune disease characterised by antibodies to DNA (anti-DNA) and other nuclear macromolecules. Anti-DNA antibodies are markers for classification and disease activity and promote pathogenesis by forming immune complexes that deposit in the tissue or stimulate cytokine production. Studies on the antibody response to DNA have focused primarily on a conformation of DNA known as B-DNA, the classic right-handed double helix. Among other conformations of DNA, Z-DNA is a left-handed helix with a zig-zag backbone; hence, the term Z-DNA. Z-DNA formation is favoured by certain base sequences, with the energetically unfavourable flip from B-DNA to Z-DNA dependent on conditions. Z-DNA differs from B-DNA in its immunogenicity in animal models. Furthermore, anti-Z-DNA antibodies, but not anti-B-DNA antibodies, can be present in otherwise healthy individuals. In SLE, antibodies to Z-DNA can occur in association with antibodies to B-DNA as a cross-reactive response, rising and falling together. While formed transiently in chromosomal DNA, Z-DNA is stably present in bacterial biofilms; biofilms can provide protection against antibiotics and other challenges including elements of host defence. The high GC content of certain bacterial DNA also favours Z-DNA formation as do DNA-binding proteins of bacterial or host origin. Together, these findings suggest that sources of Z-DNA can enhance the immunogenicity of DNA and, in SLE, stimulate the production of cross-reactive antibodies that bind both B-DNA and Z-DNA. As such, DNA can act as a molecular chameleon that, when stabilised in the Z-DNA conformation, can drive autoimmunity.

iTRAQ-based mass spectrometry screen to identify serum biomarkers in systemic lupus erythematosus.

OBJECTIVE: Systemic lupus erythematosus (SLE) is a complex systemic autoimmune disorder with no reliable serum biomarkers currently available other than autoantibodies. METHODS: In the present study, isobaric tags for relative and absolute quantitation-based mass spectrometry was used to screen the sera of patients with SLE to uncover potential disease biomarkers. RESULTS: 85 common proteins were identified, with 16 being elevated (≥1.3) and 23 being decreased (≤0.7) in SLE. Of the 16 elevated proteins, serum alpha-1-microglobulin/bikunin precursor (AMBP), zinc alpha-2 glycoprotein (AZGP) and retinol-binding protein 4 (RBP4) were validated in independent cross-sectional cohorts (Cohort I, N=52; Cohort II, N=117) using an orthogonal platform, ELISA. Serum AMBP, AZGP and RBP4 were validated to be significantly elevated in both patients with inactive SLE and patients with active SLE compared with healthy controls (HCs) (p<0.05, fold change >2.5) in Cohort I. All three proteins exhibited good discriminatory power for distinguishing active SLE and inactive SLE (area under the curve=0.82-0.96), from HCs. Serum AMBP exhibited the largest fold change in active SLE (5.96) compared with HCs and correlated with renal disease activity. The elevation in serum AMBP was validated in a second cohort of patients with SLE of different ethnic origins, correlating with serum creatinine (r=0.60, p<0.001). CONCLUSION: Since serum AMBP is validated to be elevated in SLE and correlated with renal disease, the clinical utility of this novel biomarker warrants further analysis in longitudinal cohorts of patients with lupus and lupus nephritis.

Efficacy and safety of telitacicept therapy in systemic lupus erythematosus with hematological involvement.

OBJECTIVE: To evaluate the efficacy and safety of telitacicept in SLE patients specifically with hematological involvement. METHOD: A total of 22 patients with SLE and hematological involvement were included in this study. These patients received telitacicept in addition to standard therapy. We compared their demographic characteristics, clinical manifestations, and laboratory indicators before and after the administration of telitacicept. RESULTS: A total of 22 patients received telitacicept treatment for a median duration of 10.4 months (ranging from 6 to 19 months). Following telitacicept therapy, significant improvements were observed in various parameters compared to baseline. Specifically, white blood cell count increased from (3.98 ± 1.80) 109/L to (6.70 ± 2.47) 109/L, (P = 0.002), hemoglobin levels increased from (100 ± 19) g/L to (125 ± 22) g/L, (P < 0.001), and platelet count increased from (83 ± 60) 109/L to (161 ± 81) 109/L, (P = 0.004). SLE Disease Activity Index (SLEDAI) scores decreased from 12(5,15) to 0(0,4), (P < 0.001). Additionally, C3 and C4 levels showed improvement. Telitacicept treatment also resulted in a significant reduction in serum IgG levels and daily prednisone dosage. Only one adverse event (4.5%) was reported during the treatment, which was a urinary tract infection. CONCLUSION: The combination of telitacicept and standard treatment demonstrated significant improvements in anemia, as well as increased leukocyte and platelet levels in patients with SLE and hematological involvement. Importantly, the observed adverse events were manageable and controllable. Key Points • Telitacicept effectively improves anemia, clinical outcomes, and increases leukocyte and platelet counts. • Treatment with telitacicept leads to decreased levels of lgG, IgA, anti-dsDNA, and SLEDAI scores, while serum complement C3 and C4 returned to normal. • During the follow-up period there were observed changes in individual parameters, clinical symptoms, and organ involvement, all without significant adverse events.

Combination of anti-SSA/Ro60 and anti-dsDNA serotype is predictive of belimumab renal response in patients with lupus nephritis.

OBJECTIVES: To investigate the effectiveness of belimumab on active lupus nephritis (LN) and explore the predictors, including serological biomarkers, of renal response to belimumab in a real-world setting. METHODS: This multicentre, real-world observational study enrolled patients with active LN receiving intravenous belimumab as an add-on therapy with 24-hour urine protein≥1 g and estimated glomerular filtration rate≥30 mL/min/1.73 m2 at baseline. Complete renal response (CRR), partial renal response (PRR), no renal response (NRR) and primary efficacy renal response (PERR) were evaluated. Multivariable logistic regression was used to identify risk factors for NRR to belimumab at 6 months. RESULTS: Among the 122 patients enrolled, the proportions of patients achieving CRR, PRR, NRR and PERR were 35.9%, 17.1%, 47.0% and 44.4% at 6 months (n=117) and 55.6%, 19.4%, 26.4% and 58.3% at 12 months (n=72), respectively. Proteinuria, daily prednisone dosage and Systemic Lupus Erythematosus Disease Activity Index 2000 scores significantly decreased at 6 and 12 months (p<0.0001). NRR at 6 months (NRR6) was the strongest negative predictor of CRR at 12 months. Baseline anti-dsDNA positivity inversely predicted NRR6 (OR=0.32,95% CI=0.10 to 0.98, p=0.049), while anti-SSA/Ro60 positively predicted NRR6 (OR=3.16, 95% CI=1.14 to 8.74, p=0.027). The combination of anti-SSA/Ro60 and anti-dsDNA serotype quantitatively predicted belimumab renal response. CONCLUSION: The effectiveness of belimumab was reproducible in Chinese patients with active LN. The simple yet interesting serotype predictive model needs further validation and its possible underlying mechanistic relevance deserves further exploration.

Development and validation of a risk scoring system to identify patients with lupus nephritis in electronic health record data.

OBJECTIVE: Accurate identification of lupus nephritis (LN) cases is essential for patient management, research and public health initiatives. However, LN diagnosis codes in electronic health records (EHRs) are underused, hindering efficient identification. We investigated the current performance of International Classification of Diseases (ICD) codes, 9th and 10th editions (ICD9/10), for identifying prevalent LN, and developed scoring systems to increase identification of LN that are adaptable to settings with and without LN ICD codes. METHODS: Training and test sets derived from EHR data from a large health system. An external set comprised data from the EHR of a second large health system. Adults with ICD9/10 codes for SLE were included. LN cases were ascertained through manual chart reviews conducted by rheumatologists. Two definitions of LN were used: strict (definite LN) and inclusive (definite, potential or diagnostic uncertainty). Gradient boosting models including structured EHR fields were used for predictor selection. Two logistic regression-based scoring systems were developed ('LN-Code' included LN ICD codes and 'LN-No Code' did not), calibrated and validated using standard performance metrics. RESULTS: A total of 4152 patients from University of California San Francisco Medical Center and 370 patients from Zuckerberg San Francisco General Hospital and Trauma Center met the eligibility criteria. Mean age was 50 years, 87% were female. LN diagnosis codes demonstrated low sensitivity (43-73%) but high specificity (92-97%). LN-Code achieved an area under the curve (AUC) of 0.93 and a sensitivity of 0.88 for identifying LN using the inclusive definition. LN-No Code reached an AUC of 0.91 and a sensitivity of 0.95 (0.97 for the strict definition). Both scoring systems had good external validity, calibration and performance across racial and ethnic groups. CONCLUSIONS: This study quantified the underutilisation of LN diagnosis codes in EHRs and introduced two adaptable scoring systems to enhance LN identification. Further validation in diverse healthcare settings is essential to ensure their broader applicability.