Integrative analysis of single-cell and bulk transcriptome data reveal the significant role of macrophages in lupus nephritis.

OBJECTIVE: We attempted to identify abnormal immune cell components and signaling pathways in lupus nephritis (LN) and to identify potential therapeutic targets. METHODS: Differentially expressed genes (DEGs) between LN and normal kidney tissues were identified from bulk transcriptome data, and functional annotation was performed. The phenotypic changes in macrophages and aberrant intercellular signaling communications within immune cells were imputed from LN scRNA-seq data using trajectory analysis and verified using immunofluorescence staining. Finally, lentivirus-mediated overexpression of LGALS9, the gene encoding Galectin 9, in THP-1 cells was used to study the functional effect of this gene on monocytic cells. RESULTS: From bulk transcriptome data, a significant activation of interferon (IFN) signaling was observed, and its intensity showed a significantly positive correlation with the abundance of infiltrating macrophages in LN. Analysis of scRNA-seq data revealed 17 immune cell clusters, with macrophages showing the highest enrichment of intercellular signal communication in LN. Trajectory analysis revealed macrophages in LN undergo a phenotypic change from inflammatory patrolling macrophages to phagocytic and then to antigen-presenting macrophages, and secrete various pro-inflammatory factors and complement components. LGALS9 was found significantly upregulated in macrophages in LN, which was confirmed by the immunofluorescence assay. Gene functional study showed that LGALS9 overexpression in THP-1 cells significantly elicited pro-inflammatory activation, releasing multiple immune cell chemoattractants. CONCLUSION: Our results present an important pathophysiological role for macrophages in LN, and our preliminary results demonstrate significant pro-inflammatory effects of LGALS9 gene in LN macrophages.

Percutaneous kidney biopsies in children: a 24-year review in a tertiary center in northern Portugal.

INTRODUCTION: Percutaneous kidney biopsy (KB) is crucial to the diagnosis and management of several renal pathologies. National data on native KB in pediatric patients are scarce. We aimed to review the demographic and clinical characteristics and histopathological patterns in children who underwent native percutaneous KB over 24 years. METHODS: Retrospective observational study of patients undergoing native percutaneous KB in a pediatric nephrology unit between 1998 and 2021, comparing 3 periods: period 1 (1998-2005), period 2 (2006-2013), and period 3 (2014-2021). RESULTS: We found that 228 KB were performed, 78 (34.2%) in period 1, 91 (39.9%) in period 2, and 59 (25.9%) in period 3. The median age at KB was 11 (7-14) years. The main indications for KB were nephrotic syndrome (NS) (42.9%), hematuria and/or non-nephrotic proteinuria (35.5%), and acute kidney injury (13.2%). Primary glomerulopathies were more frequent (67.1%), particularly minimal change disease (MCD) (25.4%), IgA nephropathy (12.7%), and mesangioproliferative glomerulonephritis (GN) (8.8%). Of the secondary glomerulopathies, lupus nephritis (LN) was the most prevalent (11.8%). In group 1, hematuria and/or non-nephrotic proteinuria were the main reasons for KB, as opposed to NS in groups 2 and 3 (p < 0.01). LN showed an increasing trend (period 1-3: 2.6%-5.3%) and focal segmental glomerular sclerosis (FSGS) showed a slight decreasing trend (period 1-3: 3.1%-1.8%), without statistical significance. CONCLUSIONS: The main indication for KB was NS, which increased over time, justifying the finding of MCD as main histological diagnosis. LN showed an increase in incidence over time, while FSGS cases did not increase.

MiR-574-5p activates human TLR8 to promote autoimmune signaling and lupus.

Endosomal single-stranded RNA-sensing Toll-like receptor-7/8 (TLR7/8) plays a pivotal role in inflammation and immune responses and autoimmune diseases. However, the mechanisms underlying the initiation of the TLR7/8-mediated autoimmune signaling remain to be fully elucidated. Here, we demonstrate that miR-574-5p is aberrantly upregulated in tissues of lupus prone mice and in the plasma of lupus patients, with its expression levels correlating with the disease activity. miR-574-5p binds to and activates human hTLR8 or its murine ortholog mTlr7 to elicit a series of MyD88-dependent immune and inflammatory responses. These responses include the overproduction of cytokines and interferons, the activation of STAT1 signaling and B lymphocytes, and the production of autoantigens. In a transgenic mouse model, the induction of miR-574-5p overexpression is associated with increased secretion of antinuclear and anti-dsDNA antibodies, increased IgG and C3 deposit in the kidney, elevated expression of inflammatory genes in the spleen. In lupus-prone mice, lentivirus-mediated silencing of miR-574-5p significantly ameliorates major symptoms associated with lupus and lupus nephritis. Collectively, these results suggest that the miR-574-5p-hTLR8/mTlr7 signaling is an important axis of immune and inflammatory responses, contributing significantly to the development of lupus and lupus nephritis.

Reduced expressions of apoptosis-related proteins TRAIL, Bcl-2, and TNFR1 in NK cells of juvenile-onset systemic lupus erythematosus patients: relations with disease activity, nephritis, and neuropsychiatric involvement.

Background: Lupus pathogenesis is mainly ascribed to increased production and/or impaired clearance of dead cell debris. Although self-reactive T and B lymphocytes are critically linked to lupus development, neutrophils, monocytes, and natural killer (NK) cells have also been implicated. This study assessed apoptosis-related protein expressions in NK cells of patients with juvenile-onset systemic lupus erythematosus (jSLE) and relations to disease activity parameters, nephritis, and neuropsychiatric involvement. Methods: Thirty-six patients with jSLE, 13 juvenile dermatomyositis (JDM) inflammatory controls, and nine healthy controls had Fas, FasL, TRAIL, TNFR1, Bcl-2, Bax, Bim, and caspase-3 expressions in NK cells (CD3-CD16+CD56+) simultaneously determined by flow cytometry. Disease activity parameters included Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K) score, erythrocyte sedimentation rate, C-reactive protein level, anti-double strain DNA antibody level, complement fractions C3 and C4 levels. Results: Patients with jSLE had a profile of significantly reduced expression of TRAIL, Bcl-2, and TNFR1 proteins in NK cells when compared to healthy controls. Similar profile was observed in patients with jSLE with active disease, positive anti-dsDNA, nephritis, and without neuropsychiatric involvement. Patients with jSLE with positive anti-dsDNA also had reduced expression of Bax in NK cells when compared healthy controls and to those with negative anti-dsDNA. Yet, patients with jSLE with negative anti-dsDNA had reduced mean fluorescence intensity (MFI) of Bim in NK cells compared to healthy controls. Patients with jSLE with nephritis also had reduced MFI of Fas in NK cells when compared to those without nephritis. In addition, in patients with jSLE, the proportion of FasL-expressing NK cells directly correlated with the SLEDAI-2K score (rs = 0.6, p = 0.002) and inversely correlated with the C3 levels (rs = -0.5, p = 0.007). Moreover, patients with jSLE had increased NK cell percentage and caspase-3 protein expression in NK cells when compared to JDM controls. Conclusion: This study extends to NK cells an altered profile of TRAIL, Bcl-2, TNFR1, Fas, FasL, Bax, Bim, and caspase-3 proteins in patients with jSLE, particularly in those with active disease, positive anti-dsDNA, nephritis, and without neuropsychiatric involvement. This change in apoptosis-related protein expressions may contribute to the defective functions of NK cells and, consequently, to lupus development. The full clarification of the role of NK cells in jSLE pathogenesis may pave the way for new therapies like those of NK cell-based.

Analysis of m6A-regulated genes and subtype classification in lupus nephritis.

BACKGROUND: Lupus nephritis (LN) is the most common and severe clinical manifestation of systemic lupus erythematosus (SLE). N6-methyladenosine (m6A) is a reversible RNA modification and has been implicated in various biological processes. However, the roles of m6A regulators in LN are not fully demonstrated. METHODS: We downloaded the kidney tissue transcriptome dataset of LN patients and normal controls from the GEO database and extracted the expression levels of m6A regulators. We constructed and compared Random Forest (RF) and Support Vector Machine (SVM) models, and subsequently selected featured genes to develop nomogram models. The m6A subtypes were identified based on significantly differentially expressed m6A regulators, and the m6A gene subtypes were identified based on m6A-associated differential genes, and the two m6A modification patterns were comprehensively evaluated. RESULTS: We obtained the GSE32591 and GSE112943 datasets from the GEO database, including 78 LN samples and 36 normal control samples. We extracted the expression levels of 20 m6A regulators. By RF analysis we identified 7 characteristic m6A regulators and constructed nomogramh models with these 7 genes. We identified two m6A subtypes based on these seven important m6A regulators, and the immune cell infiltration levels of the two subtype clusters were significantly different. We identified two more m6A gene subtypes based on m6A-associated DEGs. We calculated the m6A scores using the principal component analysis (PCA) algorithm and found that the m6A scores of m6A cluster A and gene cluster A were lower than those of m6A cluster B and gene cluster B. In addition, we found that the levels of inflammatory factors were also significantly different between m6A clusters and gene clusters. CONCLUSION: This study confirms that m6A regulators are involved in the LN process through different modes of action and provide new diagnostic and therapeutic targets for LN.

Membranous lupus nephritis secondary to secukinumab therapy: A case report and literature review.

The interleukin (IL)-17 axis is involved in many inflammatory and autoimmune diseases. Secukinumab, an IL-17 inhibitor, has been approved for psoriasis treatment. There are accumulating cases of lupus erythematosus induced by IL-17 inhibition. Lupus nephritis after IL-17 inhibition has not been reported. We report the case of a 57-year-old man who developed membranous lupus nephritis after secukinumab treatment for psoriasis. Anti-SSA and PM-Scl antibodies were positive. dsDNA, anti-Smith, and anti-histone antibodies were negative, and serum complement was low. Secukinumab was discontinued, while tacrolimus was initiated, subsequently switched to cyclosporin, belimumab, glucocorticosteroid, and hydroxychloroquine with a good response. The relationship between lupus erythematosus and IL-17 inhibition requires further research.

Exacerbating effects of circadian rhythm disruption on the systemic lupus erythematosus.

OBJECTIVE: Circadian rhythm disruption (CRD) has been associated with inflammation and immune disorders, but its role in SLE progression is unclear. We aimed to investigate the impact of circadian rhythms on immune function and inflammation and their contribution to SLE progression to lupus nephritis (LN). METHODS: This study retrospectively analysed the clinical characteristics and transcriptional profiles of 373 samples using bioinformatics and machine-learning methods. A flare risk score (FRS) was established to predict overall disease progression for patients with lupus. Mendelian randomisation was used to analyse the causal relationship between CRD and SLE progression. RESULTS: Abnormalities in the circadian pathway were detected in patients with SLE, and lower enrichment levels suggested a disease state (normalised enrichment score=0.6714, p=0.0062). The disruption of circadian rhythms was found to be closely linked to lupus flares, with the FRS showing a strong ability to predict disease progression (area under the curve (AUC) of 5-year prediction: 0.76). The accuracy of disease prediction was improved by using a prognostic nomogram based on FRS (AUC=0.77). Additionally, Mendelian randomisation analysis revealed an inverse causal relationship between CRD and SLE (OR 0.6284 (95% CI 0.3630 to 1.0881), p=0.0485) and a positive causal relationship with glomerular disorders (OR 0.0337 (95% CI 1.634e-3 to 6.934e-1), p=0.0280). CONCLUSION: Our study reveals that genetic characteristics arising from CRD can serve as biomarkers for predicting the exacerbation of SLE. This highlights the crucial impact of CRD on the progression of lupus.

Polygenic Risk Score Predicts Earlier-Onset Adult Systemic Lupus Erythematosus and First-Year Renal Diseases in a Taiwanese Cohort.

OBJECTIVES: This study aimed to develop a predictive model using polygenic risk score (PRS) to forecast renal outcomes for adult systemic lupus erythematosus (SLE) in a Taiwanese population. METHODS: Patients with SLE (n=2782) and matched non-SLE controls (n=11 128) were genotyped using Genome-Wide TWB 2.0 single-nucleotide polymorphism (SNP) array. PRS models (C+T, LDpred2, Lassosum, PRSice-2, PRS-continuous shrinkage (CS)) were constructed for predicting SLE susceptibility. Logistic regression was assessed for C+T-based PRS association with renal involvement in patients with SLE. RESULTS: In the training set, C+T-based SLE-PRS, only incorporating 27 SNPs, outperformed other models with area under the curve (AUC) values of 0.629, surpassing Lassosum (AUC=0.621), PRSice-2 (AUC=0.615), LDpred2 (AUC=0.609) and PRS-CS (AUC=0.602). Additionally, C+T-based SLE-PRS demonstrated consistent predictive capacity in the testing set (AUC=0.620). Individuals in the highest quartile exhibited earlier SLE onset (39.06 vs 44.22 years, p<0.01), higher Systemic Lupus Erythematosus Disease Activity Index scores (3.00 vs 2.37, p=0.04), elevated risks of renal involvement within the first year of SLE diagnosis, including WHO class III-IV lupus nephritis (OR 2.36, 95% CI 1.47 to 3.80, p<0.01), estimated glomerular filtration rate <60 mL/min/1.73m2 (OR 1.49, 95% CI 1.18 to 1.89, p<0.01) and urine protein-to-creatinine ratio >150 mg/day (OR 2.07, 95% CI 1.49 to 2.89, p<0.01), along with increased seropositivity risks, compared with those in the lowest quartile. Furthermore, among patients with SLE with onset before 50 years, the highest PRS quartile was significantly associated with more serious renal diseases within the first year of SLE diagnosis. CONCLUSIONS: PRS of SLE is associated with earlier onset, renal involvement within the first year of SLE diagnosis and seropositivity in Taiwanese patients. Integrating PRS with clinical decision-making may enhance lupus nephritis screening and early treatment to improve renal outcomes in patients with SLE.

Machine learning-based identification of novel hub genes associated with oxidative stress in lupus nephritis: implications for diagnosis and therapeutic targets.

BACKGROUND: Lupus nephritis (LN) is a complication of SLE characterised by immune dysfunction and oxidative stress (OS). Limited options exist for LN. We aimed to identify LN-related OS, highlighting the need for non-invasive diagnostic and therapeutic approaches. METHODS: LN-differentially expressed genes (DEGs) were extracted from Gene Expression Omnibus datasets (GSE32591, GSE112943 and GSE104948) and Molecular Signatures Database for OS-associated DEGs (OSEGs). Functional enrichment analysis was performed for OSEGs related to LN. Weighted gene co-expression network analysis identified hub genes related to OS-LN. These hub OSEGs were refined as biomarker candidates via least absolute shrinkage and selection operator. The predictive value was validated using receiver operating characteristic (ROC) curves and nomogram for LN prognosis. We evaluated LN immune cell infiltration using single-sample gene set enrichment analysis and CIBERSORT. Additionally, gene set enrichment analysis explored the functional enrichment of hub OSEGs in LN. RESULTS: The study identified four hub genes, namely STAT1, PRODH, TXN2 and SETX, associated with OS related to LN. These genes were validated for their diagnostic potential, and their involvement in LN pathogenesis was elucidated through ROC and nomogram. Additionally, alterations in immune cell composition in LN correlated with hub OSEG expression were observed. Immunohistochemical analysis reveals that the hub gene is most correlated with activated B cells and CD8 T cells. Finally, we uncovered that the enriched pathways of OSEGs were mainly involved in the PI3K-Akt pathway and the Janus kinase-signal transducer and activator of transcription pathway. CONCLUSION: These findings contribute to advancing our understanding of the complex interplay between OS, immune dysregulation and molecular pathways in LN, laying a foundation for the identification of potential diagnostic biomarkers and therapeutic targets.

Clinicopathological correlation of patients with lupus nephritis: Data from a tertiary center in Saudi Arabia.

Systemic lupus erythematosus mainly affects young women, and approximately half of systemic lupus erythematosus patients develop lupus nephritis (LN). However, data on the types and remission rates of LN in Saudi Arabia are limited. Therefore, we aimed to highlight the LN remission rates in our population. A retrospective record review was conducted between January 2007 and December 2020 in a tertiary center in the western region of Saudi Arabia to determine the remission rates among patients with biopsy-proven LN who met the EULAR\ACR 2019 classification criteria. We identified 59 patients with biopsy-proven LN, mostly in young women. The common histopathological pattern was Class IV LN in 26 patients (44%). Three induction protocols were identified, along with systemic steroids: the high-dose cyclophosphamide protocol in 21 patients (35.6%), low-dose protocol in 4 patients (6.8%), and mycophenolate mofetil (MMF) in 41 patients (69.5%). Partial response, defined as the reduction of the 24-hour proteinuria by 25% at 3 months and 50% at 6 months, was achieved in 18 patients (33.3%) at 3 months and decreased to 13 patients (24.1%) at 6 months. Complete clinical response, defined as 24-hour urinary protein between 500 and 700 mg at 12 months, was achieved in 44 patients (81.5%). Complete remission was higher among patients with Class IV LN (64.4%). The achievement of partial clinical response at 3 months was significantly lower among patients with hypertension (P = .041). This study presented the LN remission rates in a single center in Saudi Arabia. Similar to previous studies, Class IV LN were the most common histopathological finding in this study. Complete remission at 12 months was achieved in 44 (81%) patients. Delayed remission is associated with hypertension at the time of LN diagnosis.

Animal models of lupus nephritis: the past, present and a future outlook.

Lupus nephritis (LN) is the most severe end-organ pathology in Systemic Lupus Erythematosus (SLE). Research has enhanced our understanding of immune effectors and inflammatory pathways in LN. However, even with the best available therapy, the rate of complete remission for proliferative LN remains below 50%. A deeper understanding of the resistance or susceptibility of renal cells to injury during the progression of SLE is critical for identifying new targets and developing effective long-term therapies. The complex and heterogeneous nature of LN, combined with the limitations of clinical research, make it challenging to investigate the aetiology of this disease directly in patients. Hence, multiple murine models resembling SLE-driven nephritis are utilised to dissect LN's cellular and genetic mechanisms, identify therapeutic targets, and screen novel compounds. This review discusses commonly used spontaneous and inducible mouse models that have provided insights into pathogenic mechanisms and long-term maintenance therapies in LN.

Advancing Point-of-Care Diagnosis: Digitalizing Combinatorial Biomarker Signals for Lupus Nephritis.

To improve the efficiency and patient coverage of the current healthcare system, user-friendly novel homecare devices are urgently needed. In this work, we developed a smartphone-based analyzing and reporting system (SBARS) for biomarker detection in lupus nephritis (LN). This system offers a cost-effective alternative to traditional, expensive large equipment in signal detection and quantification. This innovative approach involves using a portable and affordable microscopic reader to capture biomarker signals. Through smartphone-based image processing techniques, the intensity of each biomarker signal is analyzed. This system exhibited comparable performance to a commercial Genepix scanner in the detection of two potential novel biomarkers of LN, VISG4 and TNFRSF1b. Importantly, this smartphone-based analyzing and reporting system allows for discriminating LN patients with active renal disease from healthy controls with the area-under-the-curve (AUC) value = 0.9 for TNFRSF1b and 1.0 for VSIG4, respectively, indicating high predictive accuracy.

Uncovering lupus nephritis-specific genes and the potential of TNFRSF17-targeted immunotherapy: a high-throughput sequencing study.

Introduction: Lupus nephritis (LN) is a severe manifestation of systemic lupus erythematosus (SLE). This study aimed to identify LN specific-genes and potential therapeutic targets. Methods: We performed high-throughput transcriptome sequencing on peripheral blood mononuclear cells (PBMCs) from LN patients. Healthy individuals and SLE patients without LN were used as controls. To validate the sequencing results, qRT-PCR was performed for 5 upregulated and 5 downregulated genes. Furthermore, the effect of the TNFRSF17-targeting drug IBI379 on patient plasma cells and B cells was evaluated by flow cytometry. Results: Our analysis identified 1493 and 205 differential genes in the LN group compared to the control and SLE without LN groups respectively, with 70 genes common to both sets, marking them as LN-specific. These LN-specific genes were significantly enriched in the 'regulation of biological quality' GO term and the cell cycle pathway. Notably, several genes including TNFRSF17 were significantly overexpressed in the kidneys of both LN patients and NZB/W mice. TNFRSF17 levels correlated positively with urinary protein levels, and negatively with complement C3 and C4 levels in LN patients. The TNFRSF17-targeting drug IBI379 effectively induced apoptosis in patient plasma cells without significantly affecting B cells. Discussion: Our findings suggest that TNFRSF17 could serve as a potential therapeutic target for LN. Moreover, IBI379 is presented as a promising treatment option for LN.

Sodium-glucose cotransporter 2 inhibitors: are they ready for prime time in the management of lupus nephritis?

PURPOSE OF REVIEW: Lupus nephritis is a common complication of systemic lupus erythematosus and is associated with significant morbidity and mortality. The utility of sodium-glucose cotransporter 2 (SGLT2) inhibitors in the management of lupus nephritis is currently uncertain. Here, we summarize the rationale for their use among patient with lupus nephritis. RECENT FINDINGS: SGLT2 inhibitors were initially developed as antihyperglycemic agents. They have since been shown to have additional, profound effects to slow the progression of chronic kidney disease and lessen the long-term risks of cardiovascular disease in large clinic trials of patients with chronic kidney disease, with and without diabetes, as well as in patients with and without proteinuria. Patients with recent exposure to immunosuppression were excluded from these trials due to concern for risk of infection. In the few, small trials of patients with lupus nephritis, SGLT2 inhibitors were found to be well tolerated. They have been shown to reduce proteinuria and to have modest beneficial effects on blood pressure and BMI among patients with lupus nephritis. They have not been shown to influence disease activity. SUMMARY: SGLT2 inhibitors may have a role in mitigating the chronic renal and cardiovascular effects of lupus nephritis. They should be introduced after kidney function has been stabilized with appropriate immunosuppression, in conjunction with angiotensin-converting enzyme inhibitors or angiotensin receptor blockers. They currently have no role in active disease.

Paeonol interferes with lupus nephritis by regulating M1/M2 polarization of macrophages.

Systemic lupus erythematosus (SLE) is a complex autoimmune disease of unknown etiology. It is marked by the production of pathogenic autoantibodies and the deposition of immune complexes. Lupus nephritis (LN) is a prevalent and challenging clinical complications of SLE. Cortex Moutan contains paeonol as its main effective component. In this study, using the animal model of SLE induced by R848, it was found that paeonol could alleviate the lupus-like symptoms of lupus mouse model induced by R848 activating TLR7, reduce the mortality and ameliorate the renal damage of mice. In order to explore the mechanism of paeonol on lupus nephritis, we studied the effect of paeonol on the polarization of Raw264.7 macrophages in vitro. The experimental results show that paeonol can inhibit the polarization of macrophages to M1 and promote their polarization to M2, which may be related to the inhibition of MAPK and NF-κB signaling pathways. Our research provides a new insight into paeonol in the treatment of lupus nephritis, which is of great importance for the treatment of systemic lupus erythematosus and its complications.

Initiation of belimumab with higher daily prednisolone is effective for rapid glucocorticoid reduction: A 96-week retrospective study.

OBJECTIVES: For appropriate glucocorticoid (GC) reduction, we investigated the optimal strategy including baseline factors that could reduce GC more than 50% with 96 weeks of belimumab. METHODS: This is a retrospective cohort study of Kakogawa Central City hospital from 2019 to 2023. We identified SLE patients who were receiving 200 mg of belimumab weekly by subcutaneous injection for 96 weeks. The background at baseline, trends in clinical indicators, and factors involved in GC reduction were statistically analyzed. Finally, univariate and multivariate logistic analyses were carried out to identify baseline factors associated ≥50% GC reduction at 96 weeks. RESULTS: Forty-seven patients were enrolled, with a median daily prednisolone of 5 mg. Almost 90% of them received concomitant immunosuppressants and/or hydroxychloroquine. Serological indices, daily GC dose, and SLEDAI-2K scores showed significant improvement in 96 weeks. At baseline, a significant negative correlation has been shown between the daily dose of GC and the duration from onset or last flare, as well as C4 levels. At 96 weeks, GC reduction rate and SLEDAI-2K scores were negatively correlated with duration from onset or last flare to initiation of belimumab. Mycophenolate mofetil use was significantly frequent in patients with lupus nephritis (LN), which also correlated with the frequency of past flares. In addition, LN presence was associated with higher SLEDAI-2K scores at 96 weeks, and baseline SLEDAI-2K ≥10 was associated with significantly higher GC dose at 96 weeks. Univariate analysis of the factor contributing to achieving ≥50% GC reduction at 96 weeks has pointed shorter disease duration and higher daily GC dose at baseline as significant variables. Finally, we performed a multivariate analysis by combining above two items with age, which extracted the higher daily GC dose at baseline as a significant variable (OR (95% CI) 1.25 (1.00 to 1.56), p = .047). CONCLUSIONS: Our study showed that a delay in belimumab initiation led to higher SLEDAI-2K score and difficulty in achieving a 50% GC reduction at 96 weeks. Since GC-related adverse events increase with long-term administration of GC though with small daily doses, we proposed here that belimumab should be started in combination with higher daily prednisolone.

Epidemiological, immunological, and treatment response profile of patients with lupus nephritis in Brazil.

BACKGROUND AND HYPOTHESIS: Brazil has the largest number of individuals of African descent outside Africa and a very admixed population. Among cases of lupus nephritis (LN) in the country, there are differences in incidence, and even in severity, depending on the location and characteristics of the population studied. The aim of this study was to describe the clinical and epidemiological characteristics of LN in Brazil, as well as to determine which of those characteristics would be risk factors for a poor renal prognosis. METHODS: This was a retrospective, descriptive observational study of patients diagnosed with LN who underwent kidney biopsy between 1999 and 2015 in the Nephrology Department of the Hospital das Clínicas, in São Paulo, Brazil. Data were collected from electronic medical records. RESULTS: We evaluated 398 patients, among who 94.1% and 77.7% tested positive for antinuclear antibodies and anti-DNA antibodies, respectively, whereas 33.7% showed the full-house pattern. The time from LN symptom onset to biopsy was <6 months in 47.5% (early biopsy group) and ≥6 months in 52.5% (late biopsy group). In the early biopsy group, the chronicity index was lower and the activity index was higher. Multivariate analysis showed that a higher chronicity index was the only independent risk factor for progression to requiring kidney replacement therapy. CONCLUSION: Late biopsy seems to be associated with negative renal outcomes in LN. However, it seems that a higher chronicity index is the main predictor of a poor renal outcome among patients with LN in Brazil.

Functional consequence of Iron dyshomeostasis and ferroptosis in systemic lupus erythematosus and lupus nephritis.

Systemic lupus erythematosus (SLE) and its renal manifestation Lupus nephritis (LN) are characterized by a dysregulated immune system, autoantibodies, and injury to the renal parenchyma. Iron accumulation and ferroptosis in the immune effectors and renal tubules are recently identified pathological features in SLE and LN. Ferroptosis is an iron dependent non-apoptotic form of regulated cell death and ferroptosis inhibitors have improved disease outcomes in murine models of SLE, identifying it as a novel druggable target. In this review, we discuss novel mechanisms by which iron accumulation and ferroptosis perpetuate immune cell mediated pathology in SLE/LN. We highlight intra-renal dysregulation of iron metabolism and ferroptosis as an underlying pathogenic mechanism of renal tubular injury. The basic concepts of iron biology and ferroptosis are also discussed to expose the links between iron, cell metabolism and ferroptosis, that identify intracellular pro-ferroptotic enzymes and their protein conjugates as potential targets to improve SLE/LN outcomes.