Lupus nephritis: the evolving role of novel therapeutics

The impact of antiphospholipid antibodies/antiphospholipid syndrome on systemic lupus erythematosus

aPLs are a major determinant of the increased cardiovascular risk in patients with SLE. They adversely affect clinical manifestations, damage accrual and prognosis. Apart from the antibodies included in the 2006 revised classification criteria for APS, other non-classical aPLs might help in identifying SLE patients at increased risk of thrombotic events. The best studied are IgA anti-β2-glycoprotein I, anti-domain I β2-glycoprotein I and aPS-PT. Major organ involvement includes kidney and neuropsychiatric systems. aPL/APS severely impacts pregnancy outcomes. Due to increased thrombotic risk, these patients require aggressive cardiovascular risk factor control. Primary prophylaxis is based on low-dose aspirin in high-risk patients. Warfarin is the gold-standard drug for secondary prophylaxis.

Anti-inflammatory effect of dental pulp stem cells

Dental pulp stem cells (DPSCs) have received a lot of attention as a regenerative medicine tool with strong immunomodulatory capabilities. The excessive inflammatory response involves a variety of immune cells, cytokines, and has a considerable impact on tissue regeneration. The use of DPSCs for controlling inflammation for the purpose of treating inflammation-related diseases and autoimmune disorders such as supraspinal nerve inflammation, inflammation of the pulmonary airways, systemic lupus erythematosus, and diabetes mellitus is likely to be safer and more regenerative than traditional medicines. The mechanism of the anti-inflammatory and immunomodulatory effects of DPSCs is relatively complex, and it may be that they themselves or some of the substances they secrete regulate a variety of immune cells through inflammatory immune-related signaling pathways. Most of the current studies are still at the laboratory cellular level and animal model level, and it is believed that through the efforts of more researchers, DPSCs/SHED are expected to be transformed into excellent drugs for the clinical treatment of related diseases.

Unveiling the Hidden Power of Uromodulin: A Promising Potential Biomarker for Kidney Diseases

Uromodulin, also known as Tamm-Horsfall protein, represents the predominant urinary protein in healthy individuals. Over the years, studies have revealed compelling associations between urinary and serum concentrations of uromodulin and various parameters, encompassing kidney function, graft survival, cardiovascular disease, glucose metabolism, and overall mortality. Consequently, there has been a growing interest in uromodulin as a novel and effective biomarker with potential applications in diverse clinical settings. Reduced urinary uromodulin levels have been linked to an elevated risk of acute kidney injury (AKI) following cardiac surgery. In the context of chronic kidney disease (CKD) of different etiologies, urinary uromodulin levels tend to decrease significantly and are strongly correlated with variations in estimated glomerular filtration rate. The presence of uromodulin in the serum, attributable to basolateral epithelial cell leakage in the thick ascending limb, has been observed. This serum uromodulin level is closely associated with kidney function and histological severity, suggesting its potential as a biomarker capable of reflecting disease severity across a spectrum of kidney disorders. The UMOD gene has emerged as a prominent locus linked to kidney function parameters and CKD risk within the general population. Extensive research in multiple disciplines has underscored the biological significance of the top UMOD gene variants, which have also been associated with hypertension and kidney stones, thus highlighting the diverse and significant impact of uromodulin on kidney-related conditions. UMOD gene mutations are implicated in uromodulin-associated kidney disease, while polymorphisms in the UMOD gene show a significant association with CKD. In conclusion, uromodulin holds great promise as an informative biomarker, providing valuable insights into kidney function and disease progression in various clinical scenarios. The identification of UMOD gene variants further strengthens its relevance as a potential target for better understanding kidney-related pathologies and devising novel therapeutic strategies. Future investigations into the roles of uromodulin and regulatory mechanisms are likely to yield even more profound implications for kidney disease diagnosis, risk assessment, and management.

Spatial proteomics landscape and immune signature analysis of renal sample of lupus nephritis based on laser-captured microsection

OBJECTIVE

We aimed to reveal a spatial proteomic and immune signature of kidney function regions in lupus nephritis (LN).

MATERIAL AND METHODS

The laser capture microdissection (LCM) was used to isolate the glomerulus, tubules, and interstitial of the kidney from paraffin samples. The data-independent acquisition (DIA) method was used to collect proteomics data. The bioinformatic analysis was performed.

RESULTS

A total of 49,658 peptides and 4056 proteins were quantitated. Our results first showed that a high proportion of activated NK cells, naive B cells, and neutrophils in the glomerulus, activated NK cells in interstitial, and resting NK cells were accumulated in tubules in LN. The immune-related function analysis of differential expression proteins in different regions indicated that the glomerulus and interstitial were major sites of immune disturbance and regulation connected with immune response activation. Furthermore, we identified 7, 8, and 9 hub genes in LN's glomerulus, renal interstitial, and tubules. These hub genes were significantly correlated with the infiltration of immune cell subsets. We screened out ALB, CTSB, LCN2, A2M, CDC42, VIM, LTF, and CD14, which show higher performance as candidate biomarkers after correlation analysis with clinical indexes. The function within three regions of the kidney was analyzed. The differential expression proteins (DEGs) between interstitial and glomerulus were significantly enriched in the immune-related biological processes, and myeloid leukocyte-mediated immunity and cellular response to hormone stimulus. The DEGs between tubules and glomerulus were significantly enriched in cell activation and leukocyte-mediated immunity. While the DEGs between tubules and interstitial were enriched in response to lipid, antigen processing, and presentation of peptide antigen response to oxygen-containing compound, the results indicated a different function within kidney regions.

CONCLUSIONS

Collectively, we revealed spatial proteomics and immune signature of LN kidney regions by combined using LCM and DIA.

Low serum uromodulin levels and their association with lupus flares

BACKGROUND

Only two previous studies in systemic lupus erythematosus (SLE) patients have identified that the blood concentrations of uromodulin are lower in nephritis. However, none of them had evaluated whether a low serum uromodulin adjusted by the glomerular filtration rate (sUromod/eGFR index) contributed to identify patients in risk of lupus nephritis (LN) using multivariable models.

AIM

Therefore, this study aimed two objectives to evaluate the association between low serum uromodulin levels and low sUromod adjusted by eGFR with renal flares in SLE excluding effects of potential confounders in multivariable analyses; and to identify the value of low sUmod and low sUmod/eGFR index as a potential diagnostic marker of LN.

PATIENTS AND METHODS

Design: Cross-sectional study. SLE patients (n = 114) were investigated for lupus flare with renal SLEDAI. Two groups: a) SLE with renal flare (renal-SLEDAI≥4, n = 41) and b) SLE non-renal flare (renal SLEDAI<4, n = 73). SLE patients were evaluated by other indices including a global disease activity index (SLEDAI) and SLICC renal disease activity score. Serum uromodulin levels (ng/mL) were quantified by ELISA. Serum uromodulin was adjusted by eGFR (sUromod/eGFR index). Cutt-offs of low sUromodulin and low sUromod/eGFR index were computed, ROC curves were performed and values of diagnostic tests were obtained. Multivariable logistic regression models were performed to identify if low sUromod/eGFR index is associated to renal flares.

RESULTS

Low serum uromodulin and low sUromod/eGFR index correlated to high scores of renal-SLEDAI, SLICC-renal and proteinuria. SLE patients with a renal flare had lower uromodulin levels compared to SLE patients without renal flare (p = 0.004). After adjusting by potential confounders, the low sUromod/eGFR index (<0.80 ng/mL) increased the risk of a renal flare (OR, 2.91; 95%CI, 1.21 to 6.98; p = 0.02).

CONCLUSIONS

We propose the low sUromod/eGFR index as a potential new marker of renal disease activity in SLE.

The evolving story of apolipoprotein L1 nephropathy: the end of the beginning

Genetic coding variants in APOL1, which encodes apolipoprotein L1 (APOL1), were identified in 2010 and are relatively common among individuals of sub-Saharan African ancestry. Approximately 13% of African Americans carry two APOL1 risk alleles. These variants, termed G1 and G2, are a frequent cause of kidney disease — termed APOL1 nephropathy — that typically manifests as focal segmental glomerulosclerosis and the clinical syndrome of hypertension and arterionephrosclerosis. Cell culture studies suggest that APOL1 variants cause cell dysfunction through several processes, including alterations in cation channel activity, inflammasome activation, increased endoplasmic reticulum stress, activation of protein kinase R, mitochondrial dysfunction and disruption of APOL1 ubiquitinylation. Risk of APOL1 nephropathy is mostly confined to individuals with two APOL1 risk variants. However, only a minority of individuals with two APOL1 risk alleles develop kidney disease, suggesting the need for a ‘second hit’. The best recognized factor responsible for this ‘second hit’ is a chronic viral infection, particularly HIV-1, resulting in interferon-mediated activation of the APOL1 promoter, although most individuals with APOL1 nephropathy do not have an obvious cofactor. Current therapies for APOL1 nephropathies are not adequate to halt progression of chronic kidney disease, and new targeted molecular therapies are in clinical trials.

This Review summarizes current understanding of the role of APOL1 variants in kidney disease. The authors discuss the genetics, protein structure and biological functions of APOL1 variants and provide an overview of promising therapeutic strategies.

In contrast to other APOL family members, which are primarily intracellular, APOL1 contains a unique secretory signal peptide, resulting in its secretion into plasma.

APOL1 renal risk alleles provide protection from African human trypanosomiasis but are a risk factor for progressive kidney disease in those carrying two risk alleles.

APOL1 risk allele frequency is ~35% in the African American population in the United States, with ~13% of individuals having two risk alleles; the highest allele frequencies are found in West African populations and their descendants.

Cell and mouse models implicate endolysosomal and mitochondrial dysfunction, altered ion channel activity, altered autophagy, and activation of protein kinase R in the pathogenesis of APOL1-associated kidney disease; however, the relevance of these injury pathways to human disease has not been resolved.

APOL1 kidney disease tends to be progressive, and current standard therapies are generally ineffective; targeted therapeutic strategies hold the most promise.

Tissue resident cell processes determine organ damage in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease that affects almost any organ. Multiple immunological abnormalities involving every domain of the immune system contribute to the expression of the disease. It is now recognized that elements of the immune system instigate processes in tissue resident cells which execute organ damage. Although correction of ongoing immune aberrations is important in the control of disease activity, targeting tissue specific injurious processes may prove desirable in limiting organ damage.

HSPB5 suppresses renal inflammation and protects lupus-prone NZB/W F1 mice from severe renal damage

BACKGROUND

Lupus nephritis (LN) is an inflammatory disease of the kidneys affecting patients with systemic lupus erythematosus. Current immunosuppressive and cytotoxic therapies are associated with serious side effects and fail to protect 20-40% of LN patients from end-stage renal disease. In this study, we investigated whether a small heat shock protein, HSPB5, can reduce kidney inflammation and the clinical manifestations of the disease in NZB/W F1 mice. Furthermore, we investigated whether HSPB5 can enhance the effects of methylprednisolone, a standard-of-care drug in LN, in an endotoxemia mouse model.

METHODS

NZB/W F1 mice were treated with HSPB5, methylprednisolone, or vehicle from 23 to 38 weeks of age. Disease progression was evaluated by weekly proteinuria scores. At the end of the study, the blood, urine, spleens, and kidneys were collected for the assessment of proteinuria, blood urea nitrogen, kidney histology, serum IL-6 and anti-dsDNA levels, immune cell populations, and their phenotypes, as well as the transcript levels of proinflammatory chemokine/cytokines in the kidneys. HSPB5 was also evaluated in combination with methylprednisolone in a lipopolysaccharide-induced endotoxemia mouse model; serum IL-6 levels were measured at 24 h post-endotoxemia induction.

RESULTS

HSPB5 significantly reduced terminal proteinuria and BUN and substantially improved kidney pathology. Similar trends, although to a lower extent, were observed with methylprednisolone treatment. Serum IL-6 levels and kidney expression of BAFF, IL-6, IFNγ, MCP-1 (CCL2), and KIM-1 were reduced, whereas nephrin expression was significantly preserved compared to vehicle-treated mice. Lastly, splenic Tregs and Bregs were significantly induced with HSPB5 treatment. HSPB5 in combination with methylprednisolone also significantly reduced serum IL-6 levels in endotoxemia mice.

CONCLUSIONS

HSPB5 treatment reduces kidney inflammation and injury, providing therapeutic benefits in NZB/W F1 mice. Given that HSPB5 enhances the anti-inflammatory effects of methylprednisolone, there is a strong interest to develop HSBP5 as a therapeutic for the treatment of LN.

Prognostic and Diagnostic Values of Novel Serum and Urine Biomarkers in Lupus Nephritis: A Systematic Review

INTRODUCTION

While renal biopsy remains the gold standard for diagnosing lupus nephritis (LN), the prognostic and diagnostic role of non-invasive biomarkers for LN is currently debated.

METHODS

Available studies published in last 5 years (2015-2020) assessing the diagnostic and prognostic value of urinary and/or serological biomarkers in subjects with LN were analyzed in this systematic review.

RESULTS

Eighty-five studies were included (comprehending 13,496 patients with systemic lupus erythematosus [SLE], 8,872 LN, 487 pediatric LN, 3,977 SLE but no LN, 160 pediatric SLE but no LN and 7,679 controls). Most of the studies were cross-sectional (62; 73%), while 14 (17%) were prospective. In sixty studies (71%), the diagnosis of LN was biopsy-confirmed. Forty-four out of 85 (52%) investigated only serological biomarkers, 29 studies (34%) tested their population only with urinary biomarkers, and 12 (14%) investigated the presence of both. Outcome measures to assess the clinical utility of the analyzed biomarkers were heterogeneous, including up to 21 different activity scores, with the SLEDAI (in 60%) being the most used. Despite some heterogeneity, promising results have been shown for biomarkers such as urinary monocyte chemoattractant protein, urinary adiponectin, and urinary vascular cell adhesion protein 1.

DISCUSSION/CONCLUSION

While serum and urine biomarkers have the potential to improve diagnostic and prognostic pathways in patients with LN, the vast heterogeneity across studies severely limits their applicability in current clinical practice. With the kidney biopsy still representing the gold standard, future efforts should focus on harmonizing study inclusion criteria and outcomes, particularly in clinical trials, in order to improve comparability and facilitate the implementations of available biomarkers into the daily practice.

Iron Metabolism: An Under Investigated Driver of Renal Pathology in Lupus Nephritis

Nephritis is a common manifestation of systemic lupus erythematosus, a condition associated with inflammation and iron imbalance. Renal tubules are the work horse of the nephron. They contain a large number of mitochondria that require iron for oxidative phosphorylation, and a tight control of intracellular iron prevents excessive generation of reactive oxygen species. Iron supply to the kidney is dependent on systemic iron availability, which is regulated by the hepcidin-ferroportin axis. Most of the filtered plasma iron is reabsorbed in proximal tubules, a process that is controlled in part by iron regulatory proteins. This review summarizes tubulointerstitial injury in lupus nephritis and current understanding of how renal tubular cells regulate intracellular iron levels, highlighting the role of iron imbalance in the proximal tubules as a driver of tubulointerstitial injury in lupus nephritis. We propose a model based on the dynamic ability of iron to catalyze reactive oxygen species, which can lead to an accumulation of lipid hydroperoxides in proximal tubular epithelial cells. These iron-catalyzed oxidative species can also accentuate protein and autoantibody-induced inflammatory transcription factors leading to matrix, cytokine/chemokine production and immune cell infiltration. This could potentially explain the interplay between increased glomerular permeability and the ensuing tubular injury, tubulointerstitial inflammation and progression to renal failure in LN, and open new avenues of research to develop novel therapies targeting iron metabolism.

CX3CR1 might be a promising predictor of systemic lupus erythematosus patients with pulmonary fibrosis

The inflammatory process in systemic lupus erythematosus (SLE) affects many organs including the lungs. Chemokines are suggested to play important roles in the pathogenesis of SLE with pulmonary fibrosis (PF). In the present study, our objective is to evaluate the correlation between chemokines and PF in SLE patients. Transcriptome sequencing analysis was used to find the different expressed genes between SLE patients with PF and without PF. Enzyme-linked immunosorbent assay (ELISA) was used to detect serum levels of chemokines in SLE patients and healthy controls. Expression of CX3CR1 was measured by real-time polymerase chain reaction (PCR) and flow cytometer. Sixteen differentially chemokine genes were found to be associated to SLE with PF. Meanwhile, the upregulation of C-X3-C motif chemokine receptor 1 (CX3CR1) and its ligand, CX3C chemokine ligand 1 (CX3CL1) were observed in SLE patients with PF than that of SLE patients without PF and healthy control. Phenotypic analysis also showed that the surface expression of CX3CR1 increased in PBMCs from SLE patients with PF. Our observations indicated that CX3CL1/CX3CR1 axis is associated with PF in SLE. CX3CR1 might be a promising predictor of SLE with PF and the interactions between CX3CL1 and CX3CR1 might provide potential candidate target for the treatment of SLE with PF.

A Novel Inflammatory Dendritic Cell That Is Abundant and Contiguous to T Cells in the Kidneys of Patients With Lupus Nephritis

The mechanisms that promote local inflammatory injury during lupus nephritis (LN) flare are largely unknown. Understanding the key immune cells that drive intrarenal inflammation will advance our knowledge of disease pathogenesis and inform the development of new therapeutics for LN management. In this study, we analyzed kidney biopsies from patients with proliferative LN and identified a novel inflammatory dendritic cell (infDC) population that is highly expressed in the LN kidney, but minimally present in healthy human kidneys. During an agnostic evaluation of immune transcript expression in the kidneys of patients with proliferative LN, the most abundantly overexpressed transcript from isolated glomeruli was FCER1G, which encodes the Fc receptor gamma chain (FcRγ). To identify the cell types expressing FcRγ that infiltrate the kidney in LN, studies were done on kidney biopsies from patients with active LN using confocal immunofluorescence (IF) microscopy. This showed that FcRγ is abundantly present in the periglomerular (PG) region of the kidney and to a lesser extent in the tubulointerstitium (TI). Further investigation of the surface markers of these cells showed that they were FcRγ+, MHC II+, CD11c+, CD163+, CD5-, DC-SIGN+, CD64+, CD14+, CD16+, SIRPα+, CD206-, CD68-, CD123-, CD3-, and CD11b-, suggesting the cells were infDCs. Quantification of the infDCs showed an average 10-fold higher level of infDCs in the LN kidney compared to the healthy kidneys. Importantly, IF identified CD3+ T cells to be adjacent to these infDCs in the PG space of the LN kidney, whereas both cell types are minimally present in the healthy kidney. Thus, we have identified a previously undescribed DC in lupus kidneys that may interact with intrarenal T cells and play a role in the pathogenesis of kidney injury during LN flare.

Quantifying the effects of biopsy fixation and staining panel design on automatic instance segmentation of immune cells in human lupus nephritis

SIGNIFICANCE

Lupus nephritis (LuN) is a chronic inflammatory kidney disease. The cellular mechanisms by which LuN progresses to kidney failure are poorly characterized. Automated instance segmentation of immune cells in immunofluorescence images of LuN can probe these cellular interactions.

AIM

Our specific goal is to quantify how sample fixation and staining panel design impact automated instance segmentation and characterization of immune cells.

APPROACH

Convolutional neural networks (CNNs) were trained to segment immune cells in fluorescence confocal images of LuN biopsies. Three datasets were used to probe the effects of fixation methods on cell features and the effects of one-marker versus two-marker per cell staining panels on CNN performance.

RESULTS

Networks trained for multi-class instance segmentation on fresh-frozen and formalin-fixed, paraffin-embedded (FFPE) samples stained with a two-marker panel had sensitivities of 0.87 and 0.91 and specificities of 0.82 and 0.88, respectively. Training on samples with a one-marker panel reduced sensitivity (0.72). Cell size and intercellular distances were significantly smaller in FFPE samples compared to fresh frozen (Kolmogorov-Smirnov, p  ≪  0.0001).

CONCLUSIONS

Fixation method significantly reduces cell size and intercellular distances in LuN biopsies. The use of two markers to identify cell subsets showed improved CNN sensitivity relative to using a single marker.

Clinical and histopathological features and short-term outcomes of lupus nephritis: a prospective study of 100 Egyptian patients

OBJECTIVE

The short-term outcomes of lupus nephritis (LN) are variable and unpredictable among individuals. We aimed to evaluate the clinical and histopathological features and short-term renal outcomes in LN patients.

METHODS

This was a prospective cohort study carried out at nephrology and rheumatology units in Egypt between 2018 and 2019. A total of 100 patients with biopsy-proven LN were studied. Patients were evaluated for response after six months.

RESULTS

The female-to-male ratio was 8.1:1. About 70% of patients were hypertensive at disease onset, with rates for classes I, II, III, IV, V and VI LN being 1%, 7%, 20%, 53%, 14% and 6%, respectively. Among the immunosuppressive drugs used for induction, mycophenolate mofetil (MMF) represented the most commonly used (44%) followed by cyclophosphamide (CYC; 37%). After six months of follow-up, about two thirds of patients achieved remission. There was no significant difference in remission rate between MMF and CYC. On multivariate analysis, serum creatinine (SCr) at presentation was the most significant predictor of renal recovery. According to the receiver operating characteristic curve, the cut-off value of SCr was 1.6 mg/dL, with a sensitivity of 76% and specificity of 71% predicting renal recovery. Repeat renal biopsy was needed in 10 patients; class and treatment strategy changed in 40% and 70% of them, respectively.

CONCLUSION

Our findings in Egyptian LN patients compare favourably with most studies.

Small molecule drugs in the treatment of inflammatory bowel diseases: which one, when and why? - a systematic review

In the 'treat-to-target' era of inflammatory bowel disease (IBD) management, small molecule drugs (SMDs) represent a promising alternative to biomolecular drugs. Moreover, increasing failure rates of anti-tumor necrosis factor α agents have contributed to the development of new molecules with different mechanisms of action and bioavailability. This review focuses on the positioning of new, orally targeted therapies in the treatment algorithm of both Crohn's disease (CD) and ulcerative colitis (UC), with special consideration to their efficacy and safety. We performed a comprehensive search of PubMed and clinical trial registries to identify randomized controlled trials assessing SMDs in adult patients with moderate-to-severe IBD, irrespective of previous exposure to other biologics. In this review, we included 15 double-blind, placebo-controlled trials that assessed the efficacy and safety of Janus kinase inhibitors, sphingosine-1-phosphate modulators (S1P), SMAD blockers, phosphodiesterase 4 inhibitors and α-4 antagonists. The primary endpoints in UC were achieved for tofacitinib in the phase III OCTAVE study and AJM-300, with a favorable safety profile. S1P receptor agonists, such as etrasimod and ozanimod, demonstrated favorable results in induction studies. For CD, filgotinib and upadacitinib also met the primary outcome criteria. Available data have demonstrated so far that SMDs have an advantageous safety and efficacy profile. However, their use in a clinical setting will eventually require a personalized, mechanism-based therapeutic approach.

High salt diet accelerates the progression of murine lupus through dendritic cells via the p38 MAPK and STAT1 signaling pathways

The increased incidence of systemic lupus erythematosus (SLE) in recent decades might be related to changes in modern dietary habits. Since sodium chloride (NaCl) promotes pathogenic T cell responses, we hypothesize that excessive salt intake contributes to the increased incidence of autoimmune diseases, including SLE. Given the importance of dendritic cells (DCs) in the pathogenesis of SLE, we explored the influence of an excessive sodium chloride diet on DCs in a murine SLE model. We used an induced lupus model in which bone marrow-derived dendritic cells (BMDCs) were incubated with activated lymphocyte-derived DNA (ALD-DNA) and transferred into C57BL/6 recipient mice. We observed that a high-salt diet (HSD) markedly exacerbated lupus progression, which was accompanied by increased DC activation. NaCl treatment also stimulated the maturation, activation and antigen-presenting ability of DCs in vitro. Pretreatment of BMDCs with NaCl also exacerbated BMDC-ALD-DNA-induced lupus. These mice had increased production of autoantibodies and proinflammatory cytokines, more pronounced splenomegaly and lymphadenopathy, and enhanced pathological renal lesions. The p38 MAPK–STAT1 pathway played an important role in NaCl-induced DC immune activities. Taken together, our results demonstrate that HSD intake promotes immune activation of DCs through the p38 MAPK–STAT1 signaling pathway and exacerbates the features of SLE. Thus, changes in diet may provide a novel strategy for the prevention or amelioration of lupus or other autoimmune diseases.

Long-term Safety and Effectiveness of Tacrolimus in Patients With Lupus Nephritis: 5-year Interim Postmarketing Surveillance Study in Japan (TRUST)

OBJECTIVE

To assess the long-term safety and effectiveness of tacrolimus for treating lupus nephritis (LN) in the real-world clinical setting.

METHODS

This is an ongoing, open-label, noncomparative, observational, postmarketing surveillance study conducted across 275 sites in Japan. Registered patients with LN were followed for 10 years. Here we report data relating to 5 years of tacrolimus maintenance therapy at the interim data cutoff in August 2016.

RESULTS

Of 1395 registered patients, 1355 received tacrolimus maintenance therapy for LN and provided safety data. The most common serious adverse drug reactions (ADR) included pneumonia (1.1%), herpes zoster (1.0%), cellulitis (1.0%), and diabetes mellitus (1.0%). ADR occurred mainly within the first 28 weeks of tacrolimus treatment, and no marked increase was observed during the follow-up period. Subgroup analyses suggested that risk factors for commonly observed ADR associated with tacrolimus included inpatient management, LN disease severity, increasing age, abnormal renal or hepatic function, and comorbid or previous disease. The cumulative rate of progression to renal failure (based on the attending physician's assessment) was 0.8% at Year 1 and 6.6% at Year 5. Cumulative relapse rates were 7.8% and 30.6%, respectively. Urine protein:creatinine ratio, serum anti-dsDNA antibody levels, complement C3 levels, and steroid-sparing effects were all significantly improved from 4 weeks after tacrolimus treatment initiation (P < 0.001) and were sustained over 5 years.

CONCLUSION

Long-term tacrolimus maintenance treatment over 5 years in the real-world clinical setting was well tolerated and effective in a large population of patients with LN (www.ClinicalTrials.gov: NCT01410747).

Retinoic Acid Exerts Disease Stage-Dependent Effects on Pristane-Induced Lupus

We previously showed that all-trans-retinoic acid (tRA), an active metabolite of vitamin A, exacerbated pre-existing autoimmunity in lupus; however, its effects before the development of autoimmunity are unknown. Here, using a pristane-induced model, we show that tRA exerts differential effects when given at the initiation vs. continuation phase of lupus. Unlike tRA treatment during active disease, pre-pristane treatment with tRA aggravated glomerulonephritis through increasing renal expression of pro-fibrotic protein laminin β1, activating bone marrow conventional dendritic cells (cDCs), and upregulating the interaction of ICAM-1 and LFA-1 in the spleen, indicating an active process of leukocyte activation and trafficking. Transcriptomic analysis revealed that prior to lupus induction, tRA significantly upregulated the expression of genes associated with cDC activation and migration. Post-pristane tRA treatment, on the other hand, did not significantly alter the severity of glomerulonephritis; rather, it exerted immunosuppressive functions of decreasing circulatory and renal deposition of autoantibodies as well as suppressing the renal expression of proinflammatory cytokines and chemokines. Together, these findings suggest that tRA differentially modulate lupus-associated kidney inflammation depending on the time of administration. Interestingly, both pre- and post-pristane treatments with tRA reversed pristane-induced leaky gut and modulated the gut microbiota in a similar fashion, suggesting a gut microbiota-independent mechanism by which tRA affects the initiation vs. continuation phase of lupus.

Oxidative stress, inflammation and disease activity biomarkers in lupus nephropathy

Lupus nephropathy is a severe and frequent complication of systemic lupus erythematosus. Here, we assessed the biomarkers of oxidative stress, inflammation and disease activity in patients with lupus nephritis. Thirty-four patients with active lupus nephritis, 31 patients with inactive lupus nephritis and 20 lupus patients without renal damage (non-lupus nephritis) were studied. Oxidative stress biomarkers malonyldialdehyde, oxidized-to-total glutathione, catalase, superoxide dismutase and total antioxidant status were assessed, as well as inflammation biomarkers CRP, interleukin 6 and monocyte chemoattractant protein 1. Renal tubular disease biomarkers neutrophil gelatinase-associated lipocalin and β2-microglobulin were assessed, together with the classic disease activity biomarkers urinary protein/creatinine ratio, anti-dsDNA, anti-C1q antibody and complement proteins C3 and C4. Significant differences were found between active lupus nephritis and inactive lupus nephritis patients and between active lupus nephritis and non-lupus nephritis patients for all the assessed biomarkers (P < 0.05), except for catalase, superoxide dismutase and interleukin 6. There is an imbalance in the redox status in active lupus nephritis patients that would be involved in lipid peroxidation of the glomerular basal membrane that would alter its integrity and could also affect renal tubular function in these patients.

Drug repurposing to improve treatment of rheumatic autoimmune inflammatory diseases

The past century has been characterized by intensive efforts, within both academia and the pharmaceutical industry, to introduce new treatments to individuals with rheumatic autoimmune inflammatory diseases (RAIDs), often by 'borrowing' treatments already employed in one RAID or previously used in an entirely different disease, a concept known as drug repurposing. However, despite sharing some clinical manifestations and immune dysregulation, disease pathogenesis and phenotype vary greatly among RAIDs, and limited understanding of their aetiology has made repurposing drugs for RAIDs challenging. Nevertheless, the past century has been characterized by different 'waves' of repurposing. Early drug repurposing occurred in academia and was based on serendipitous observations or perceived disease similarity, often driven by the availability and popularity of drug classes. Since the 1990s, most biologic therapies have been developed for one or several RAIDs and then tested among the others, with varying levels of success. The past two decades have seen data-driven repurposing characterized by signature-based approaches that rely on molecular biology and genomics. Additionally, many data-driven strategies employ computational modelling and machine learning to integrate multiple sources of data. Together, these repurposing periods have led to advances in the treatment for many RAIDs.

ALW peptide ameliorates lupus nephritis in MRL/lpr mice

Background

Lupus nephritis (LN) is a common and serious complication of systemic lupus erythematosus. Anti-double-stranded (ds) DNA immunoglobulin G (IgG) plays a pivotal role in the pathogenesis of LN. Currently, there are various therapies for patients with LN; however, most of them are associated with considerable side effects. We confirmed previously that ALW (ALWPPNLHAWVP), a 12-amino acid peptide, inhibited the binding of polyclonal anti-dsDNA antibodies to mesangial cells and isolated glomeruli in vitro. In this study, we further investigate whether the administration of ALW peptide decreases renal IgG deposition and relevant damage in MRL/lpr lupus-prone mice.

Methods

Forty female MRL/lpr mice were randomly divided into four groups. The mice were intravenously injected with D-form ALW peptide (ALW group), scrambled peptide (PLP group), and normal saline (NaCl group) or were not treated (blank group). The IgG deposition, the histopathologic changes, and the expressions of profibrotic factors were analyzed in the kidney of MRL/lpr mice.

Results

Compared with the other groups, glomerular deposition of IgG, IgG2a, IgG2b, and IgG3 was decreased in the ALW group. Moreover, ALW administration attenuated renal histopathologic changes in MRL/lpr mice, including mesangial proliferation and infiltration of inflammatory cells. Furthermore, the expressions of profibrotic cytokines, such as transforming growth factor-beta1 (TGF-β1) and platelet-derived growth factor B (PDGF-B), decreased in the serum and kidney tissue of ALW-treated mice.

Conclusions

Our study demonstrated that ALW peptide ameliorates the murine model of LN, possibly through inhibiting renal IgG deposition and relevant tissue inflammation and fibrosis.

The new complement inhibitor CRIg/FH ameliorates lupus nephritis in lupus-prone MRL/lpr mice

Backgrounds

The aberrant activation of complement system is critically involved in lupus nephropathy. Recent study showed complement C3 inhibitor was effective in the treatment of lupus nephropathy. In this study, we investigate the effect of a novel complement C3 inhibitor, CRIg/FH, in the treatment of lupus nephropathy in MRL/lpr lupus mice.

Methods

We treated MRL/lpr female mice with a dose escalation of CRIg/FH (10, 5 and 2 mg/kg) by intraperitoneal injection twice weekly since 12 weeks age. In addition, MRL/lpr mice treated with intraperitoneal injection of normal saline or oral prednisone, along with C57BL/6 J healthy mice were maintained to serve as controls. We started 8-h urine collection weekly to screen proteinuria by measuring the levels of urine urea/creatinine. Serum samples was collected at week 16 and 20 to measure levels of urea nitrogen, creatinine, and immunological markers (C3, C4, A-ds-DNA) before the mice were sacrificed at 20 weeks age to collect kidneys for histopathological examinations.

Results

Overt skin lesions were observed in MRL/lpr mice treated with normal saline, while skin lesion was not observed in CRIg/FH treated MRL/lpr mice. There was no overt proteinuria observed in MRL/lpr mice treated with CRIg/FH. Serum creatinine and BUN levels in MRL/lpr mice was maintained in highest CRIg/FH dose (10 mg/kg twice a week) to be significantly lower than that in prednisone treated MRL/lpr mice at 20 weeks age. In addition, CRIg/FH treatment in MRL/lpr mice results in a significantly elevated serum C3 and C4 levels when compared to prednisone treatment at both 16 and 20 weeks. Furthermore, our study identified that serum level of A-ds-DNA was also significantly lower in CRIg/FH treatment than that in predisone treated MRL/lpr mice. Renal pathology confirmed that kidneys from CRIg/FH treated MRL/lpr mice suffered less from nephritis and complement disposition.

Conclusion

Our results showed that the complement inhibitor CRIg/FH can protect MRL/lpr mice from lupus nephropathy by preserving renal function and glomerulus complement activation. Our findings support the positive effect of complement inhibitors in the treatment of lupus nephropathy.

Association of GTF2I gene polymorphisms with renal involvement of systemic lupus erythematosus in a Chinese population

The purposes of the study was to validate the relationship between General transcription factor II-I (GTF2I) genetic variants and kidney involvements of systemic lupus erythematosus (SLE) patients in a Chinese Han population.Samples from 400 SLE patients and 400 age- and sex-matched healthy controls were collected and genotyped by improved multiplex ligation detection reaction technique. The relationship between gene polymorphism of rs117026326, rs73366469, and susceptibility, progression of SLE were analyzed.The present study provided evidence that rs117026326 and rs73366469 were both associated with SLE susceptibility (both C vs T: P < .001). The analysis of dominant, recessive disease model provided us with further validation (P < .001). Both gene polymorphisms are associated with a triad of disease manifestations among SLE patients. Patients carrying genotype TT of rs117026326 had lower 24-hour urinary total protein (24 hours UTP, g/24 hours), 24-hour urinary protein level (g/L·24 hours), lower frequency of the proteinuria and lupus nephritis (LN). Patients carrying genotype TT at rs73366469 had higher 24-hour urinary protein level, higher frequency of the proteinuria, LN and positive anti-dsDNA than those with other genotypes.This study identified the involvement of GTF2I gene polymorphisms in development of SLE, particularly in renal involvement.

Stem cells for lupus nephritis: a concise review of current knowledge

Lupus nephritis (LN), a common manifestation of systemic lupus erythematosus (SLE), accounts for significant morbidity and mortality in SLE patients. Since the available standard therapies and biologic agents for LN are yet to achieve the desired response and have considerable secondary effects, stem cell therapy has now emerged as a new approach. This therapy involves the transplantation of hematopoietic stem cells (HSCs) and mesenchymal stem cells (MSCs). Our current review will highlight the progress of stem cell therapy for LN, along with the challenges encountered and the future direction of this approach.

Immunosuppressive treatment for proliferative lupus nephritis

BACKGROUND

Cyclophosphamide, in combination with corticosteroids, has been first-line treatment for inducing disease remission for proliferative lupus nephritis, reducing death at five years from over 50% in the 1950s and 1960s to less than 10% in recent years. Several treatment strategies designed to improve remission rates and minimise toxicity have become available. Treatments, including mycophenolate mofetil (MMF) and calcineurin inhibitors, alone and in combination, may have equivalent or improved rates of remission, lower toxicity (less alopecia and ovarian failure) and uncertain effects on death, end-stage kidney disease (ESKD) and infection. This is an update of a Cochrane review first published in 2004 and updated in 2012.

OBJECTIVES

Our objective was to assess the evidence and evaluate the benefits and harms of different immunosuppressive treatments in people with biopsy-proven lupus nephritis. The following questions relating to management of proliferative lupus nephritis were addressed: 1) Are new immunosuppressive agents superior to or as effective as cyclophosphamide plus corticosteroids? 2) Which agents, dosages, routes of administration and duration of therapy should be used? 3) Which toxicities occur with the different treatment regimens?

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Specialised Register up to 2 March 2018 with support from the Cochrane Information Specialist using search terms relevant to this review. Studies in the Specialised Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs comparing any immunosuppressive treatment for biopsy-proven class III, IV, V+III and V+VI lupus nephritis in adult or paediatric patients were included.

DATA COLLECTION AND ANALYSIS

Data were abstracted and the risks of bias were assessed independently by two authors. Dichotomous outcomes were calculated as risk ratio (RR) and measures on continuous scales calculated as mean differences (MD) with 95% confidence intervals (CI). The primary outcomes were death (all causes) and complete disease remission for induction therapy and disease relapse for maintenance therapy. Evidence certainty was determined using GRADE.

MAIN RESULTS

In this review update, 26 new studies were identified, to include 74 studies involving 5175 participants overall. Twenty-nine studies included children under the age of 18 years with lupus nephritis, however only two studies exclusively examined the treatment of lupus nephritis in patients less than 18 years of age.Induction therapy Sixty-seven studies (4791 participants; median 12 months duration (range 2.5 to 48 months)) reported induction therapy. The effects of all treatment strategies on death (all causes) and ESKD were uncertain (very low certainty evidence) as this outcome occurred very infrequently. Compared with intravenous (IV) cyclophosphamide, MMF may have increased complete disease remission (RR 1.17, 95% CI 0.97 to 1.42; low certainty evidence), although the range of effects includes the possibility of little or no difference.Compared to IV cyclophosphamide, MMF is probably associated with decreased alopecia (RR 0.29, 95% CI 0.19 to 0.46; 170 less (129 less to 194 less) per 1000 people) (moderate certainty evidence), increased diarrhoea (RR 2.42, 95% CI 1.64 to 3.58; 142 more (64 more to 257 more) per 1000 people) (moderate certainty evidence) and may have made little or no difference to major infection (RR 1.02, 95% CI 0.67 to 1.54; 2 less (38 less to 62 more) per 1000 people) (low certainty evidence). It is uncertain if MMF decreased ovarian failure compared to IV cyclophosphamide because the certainty of the evidence was very low (RR 0.36, 95% CI 0.06 to 2.18; 26 less (39 less to 49 more) per 1000 people). Studies were not generally designed to measure ESKD.MMF combined with tacrolimus may have increased complete disease remission (RR 2.38, 95% CI 1.07 to 5.30; 336 more (17 to 1048 more) per 1000 people (low certainty evidence) compared with IV cyclophosphamide, however the effects on alopecia, diarrhoea, ovarian failure, and major infection remain uncertain. Compared to standard of care, the effects of biologics on most outcomes were uncertain because of low to very low certainty of evidence.Maintenance therapyNine studies (767 participants; median 30 months duration (range 6 to 63 months)) reported maintenance therapy. In maintenance therapy, disease relapse is probably increased with azathioprine compared with MMF (RR 1.75, 95% CI 1.20 to 2.55; 114 more (30 to 236 more) per 1000 people (moderate certainty evidence). Multiple other interventions were compared as maintenance therapy, but patient-outcome data were sparse leading to imprecise estimates.

AUTHORS' CONCLUSIONS

In this review update, studies assessing treatment for proliferative lupus nephritis were not designed to assess death (all causes) or ESKD. MMF may lead to increased complete disease remission compared with IV cyclophosphamide, with an acceptable adverse event profile, although evidence certainty was low and included the possibility of no difference. Calcineurin combined with lower dose MMF may improve induction of disease remission compared with IV cyclophosphamide, but the comparative safety profile of these therapies is uncertain. Azathioprine may increase disease relapse as maintenance therapy compared with MMF.

Analysis of clinical risk factors in relapsed patients with class IV lupus nephritis

The present study aimed to investigate risk factors for renal recurrence in patients with type IV lupus nephritis (LN). Univariate and multivariate analyses were conducted to using the Cox proportional hazard model and the Kaplan-Meier method. A total 244 patients were diagnosed with type IV LN; 100 (28.49%) relapsed and 144 (41.03%) recovered successfully. Kaplan-Meier method analysis indicated that patients with type IV LN affecting the digestive tract had high renal recurrence rates. Patients with hyperglobulinemia, positive anti-ribonucleoprotein and anti-Sjögren's syndrome type B (anti-SSB) antibodies, thrombus in the loop or non-inflammatory necrotizing vasculopathy also had a high recurrence rate. Furthermore, patients achieving partial remission had an increased recurrence rate compared with patients achieving complete remission. Patients undergoing maintenance treatment with glucocorticoids alone had a higher recurrence rate compared with patients who used alternative treatment schemes. Univariate and multivariate regression analyses by the Cox proportional hazard model determined that the effect of systemic lupus erythematosus in the gastrointestinal tract, increased serum globulin levels and positive anti-SSB antibody at onset were risk factors for the recurrence of LN type IV. The present study demonstrated that clinical risk factors of renal recurrence in patients with LN type IV include LN in the gastrointestinal tract, increased serum globulin levels, positive anti-SSB antibodies at onset and the use of glucocorticoid-only maintenance treatment.

Procyanidin B2 prevents lupus nephritis development in mice by inhibiting NLRP3 inflammasome activation

Lupus nephritis (LN) is a multifactorial event that contributes to the long-term mortality of systemic lupus erythematosus (SLE). Activation of NLRP3 inflammasome has been known to play a role in SLE pathogenesis. We evaluated the renal protection effects of procyanidin B2 (PCB2) and the involvement of NLRP3 in a mouse model involving MRL/lpr and MRL/MpJ mice. Kidney injury was evaluated by measuring the renal clinical and pathological features, renal immune complex deposition, and serum anti-double-stranded (anti-dsDNA) Abs. ELISA and Western blotting were used to detect NLRP3 inflammasome activation and IL-1β/IL-18 production. NLRP3 gene silencing was introduced into MRL/lpr mice by short hairpin RNA, and the renal damage was compared with the treatment of PCB2. PCB2 remarkably reduced renal damage in MRL/lpr mice, reflected by the reduced proteinuria, and serum levels of blood urea nitrogen and creatinine, as well as pathological features with less renal injury. PCB2 significantly reduced renal immune complex deposition and serum anti-dsDNA levels, notably inhibited the NLRP3 inflammasome activation, and reduced the renal and serum levels of IL-1β and IL-18 in MRL/lpr mice compared with those of NLRP3 gene-silenced MRL-lpr mice. PCB2 significantly suppressed LN in MRL-lpr mice by inhibiting the activation of NLRP3 inflammasome and subsequent IL-1β and IL-18 production. This finding explores a novel mechanism by which procyanidin exerts inflammatory suppression effects and its clinical benefits in LN prevention.

Review article: novel oral-targeted therapies in inflammatory bowel disease

BACKGROUND

There is a great unmet clinical need for efficacious, tolerable, economical and orally administrated drugs for the treatment of inflammatory bowel disease (IBD). New therapeutic avenues have become possible including the development of medications that target specific genetic pathways found to be relevant in other immune mediated diseases.

AIMS

To provide an overview of recent clinical trials for new generation oral targeted medications that may have a future role in IBD management.

METHODS

Pubmed and Medline searches were performed up to 1 March 2018 using keywords: "IBD", "UC", "CD", "inflammatory bowel disease" "ulcerative colitis", "Crohn's disease" in combination with "phase", "study", "trial" and "oral". A manual search of the clinical trial register, article reference lists, abstracts from meetings of Digestive Disease Week, United European Gastroenterology Week and ECCO congress were also conducted.

RESULTS

In randomised controlled trials primary efficacy endpoints were met for tofacitinib (JAK 1/3 inhibitor-phase III), upadacitinib (JAK 1 inhibitor-phase II) and AJM300 (α4-integrin antagonist-phase II) in ulcerative colitis. Ozanimod (S1P receptor agonist-phase II) also demonstrated clinical remission. For Crohn's disease, filgotinib (JAK1 inhibitor-phase II) met primary endpoints and laquinimod (quinolone-3-carboxide small molecule-phase II) was also efficacious. Trials using mongersen (SMAD7 inhibitor) and vidofludimus (dihydroorotate dehydrogenase inhibitor) have been halted.

CONCLUSIONS

This is potentially the start of an exciting new era in which multiple therapeutic options are at the disposal of physicians to treat IBD on an individualised basis. Head-to-head studies with existing treatments and longer term safety data are needed for this to be possible.

Renal Tubular Complement 3 Deposition in Children with Primary Nephrotic Syndrome

Background

This study aimed to investigate the clinical significance of complement 3 (C3) deposition in renal tubules of children with primary nephrotic syndrome (PNS).

Methods

The clinical and pathological characteristics of PNS were retrospectively reviewed in 99 PNS pediatric patients, who were divided into the C3 deposition and the non-C3 deposition groups.

Results

A total of 39 patients (39.39%) had renal tubule C3 deposition. In the C3 deposition group, the ratios of urine N-acetylglucosaminidase/creatinine (UNAG/Cr), urine β2 microglobulin/creatinine (Uβ2MG/Cr), and urine transferrin/creatinine (UTRF/Cr) were significantly higher than those of the non-C3 deposition group. The patients of the C3 deposition group had lower serum total protein and albumin, higher cholesterol and D-dimer (DD), lower proportion of CD3+CD8+ cells, and higher proportion of CD19+CD23+ cells. The number of the patients with interstitial fibrosis, renal cell vacuolar degeneration, renal tubular immunoglobulin deposition, and severe tubulointerstitial injury in the C3 deposition group was higher than that of the non-C3 deposition group. The C3 deposition intensity was positively correlated with the number of recurrences.

Conclusion

PNS pediatric patients with C3 deposition in renal tubules have more severe disease condition, tubulointerstitial injury, and recurrence suggesting a worse long-term prognosis.

The Spectrum of Glomerulopathies in Kashmir: A Tertiary Care Experience

BACKGROUND

There is a paucity of data on the spectrum of renal diseases prevalent in the Jammu and Kashmir region.

OBJECTIVES

To determine the spectrum of glomerulopathies in adult patients attending a tertiary care centre.

METHODS

Two hundred and twenty-one adequate biopsies from native kidneys of adult patients who presented with features suggestive of glomerular diseases at Sheri Kashmir Institute of medical sciences Srinagar Kashmir for the last 8 years were studied in a retrospective manner. Light and immunofluorescence (IF) microscopy were performed to evaluate these biopsies after obtaining well-informed consent from each patient.

RESULTS

Of the 221 biopsies carried out, 150 were performed on males and 71 on females with the mean age of 29 ± 13.5 years. The main presentation was the nephrotic syndrome in 177 (80%), hypertension in 60 (27%), renal insufficiency in 48 (21.7%), and abnormal urinary sediment in 42 (20.3%) of patients. The histopathology revealed minimal change disease (MCD) in 69 (31.2%), membranous glomerulonephritis (MGN) in 48 (21.7%), focal segmental glomerulsclerosis (FSG) in 49 (18%), and mesangioproliferative glomerulonephritis in 16 (7.2%). Patients with atypical presentation of diabetes mellitus showed diabetic nephropathy in 12 (5.4%) patients. Lupus nephritis was in 5 (2.2%) patients. Majority of the patients with MPGN had Immunoglobulin A deposits on IF. While evaluating the underlying cause of MGN, only 1 patient, a 62-year-old male, proved to have adenocarcinoma of the stomach. In the remaining patients, no secondary cause could be found. Thrombotic complications seen in our study were deep venous thrombosis, renal vein thrombosis and middle cerebral artery thrombosis.

CONCLUSION

MCD and MGN were the most common primary glomerular diseases observed in our centre.

[Lupus nephropathy: Insight in new treatments]

Systemic lupus erythematosus is a chronic autoimmune disease. Both acquired and innate immune systems are involved in the development of this systemic disease. Lupus nephritis usually is the most serious manifestation of systemic lupus erythematosus, with significant morbidity and mortality. The physiopathological development of the renal involvement of lupus has been increasingly elucidated over the years and various target therapies have recently been developed. After some physiopathological reminders, we discuss the conventional treatment of lupus nephritis as well as the various therapeutic advances, in particular the contribution and the place of the new target therapies in the treatment of the lupus nephritis.

Therapeutics for APOL1 nephropathies: putting out the fire in the podocyte

APOL1 nephropathies comprise a range of clinical and pathologic syndromes, which can be summarized as focal segmental glomerulosclerosis, in various guises, and arterionephrosclerosis, otherwise known as hypertensive kidney diseases. Current therapies for these conditions may achieve therapeutic targets, reduction in proteinuria and control of blood pressure, respectively, but often fail to halt the progressive decline in kidney function. It appears that current therapies fail to address certain underlying critical pathologic processes that are driven, particularly in podocytes and microvascular cells, by the APOL1 renal risk genetic variants. Mechanisms hypothesized to be responsible for APOL1 variant-associated cell injury can be summarized in five domains: increased APOL1 gene expression, activation of inflammasomes, activation of protein kinase R, electrolyte flux across plasma or intracellular membranes, and altered endolysosomal trafficking associated with endoplasmic reticulum stress. We briefly review the available evidence for these five mechanisms and suggest possible novel therapeutic approaches.

Neutrophil FcγRIIA promotes IgG-mediated glomerular neutrophil capture via Abl/Src kinases

The kidney glomerular capillaries are frequent sites of immune complex deposition and subsequent neutrophil accumulation in post-infectious and rapidly progressive glomerulonephritis. However, the mechanisms of neutrophil recruitment remain enigmatic, and there is no targeted therapeutic to avert this proximal event in glomerular inflammation. The uniquely human activating Fc receptor FcγRIIA promotes glomerular neutrophil accumulation and damage in anti-glomerular basement membrane-induced (anti-GBM-induced) glomerulonephritis when expressed on murine neutrophils. Here, we found that neutrophils are directly captured by immobilized IgG antibodies under physiological flow conditions in vitro through FcγRIIA-dependent, Abl/Src tyrosine kinase-mediated F-actin polymerization. Biophysical measurements showed that the lifetime of FcγRIIA-IgG bonds increased under mechanical force in an F-actin-dependent manner, which could enable the capture of neutrophils under physiological flow. Kidney intravital microscopy revealed that circulating neutrophils, which were similar in diameter to glomerular capillaries, abruptly arrested following anti-GBM antibody deposition via neutrophil FcγRIIA and Abl/Src kinases. Accordingly, inhibition of Abl/Src with bosutinib reduced FcγRIIA-mediated glomerular neutrophil accumulation and renal injury in experimental, crescentic anti-GBM nephritis. These data identify a pathway of neutrophil recruitment within glomerular capillaries following IgG deposition that may be targeted by bosutinib to avert glomerular injury.

Anti-C1q autoantibodies as markers of renal involvement in childhood-onset systemic lupus erythematosus

BACKGROUND

Childhood-onset systemic lupus erythematosus (cSLE) is rare, and considered more severe than its adult-onset counterpart. Lupus nephritis (LN) occurs more frequently in children, accounting for higher long-term morbidity and mortality compared with adults. Thus, reliable biological markers are needed to predict disease course. This study aimed to investigate the capacity of anti-C1q autoantibodies (Abs) to predict renal flare and global disease activity in cSLE patients, and association with disease activity and kidney involvement.

METHODS

Twenty-eight patients with cSLE including 19 patients (68%) with a history of LN were included retrospectively. Anti-C1q Abs were analysed by ELISA at renal flare-up or in the quiescent phase of disease and compared with Farr dsDNA assay.

RESULTS

Thirty-one flares occurred during follow-up: anti-C1q Abs were positive in 26 (84%), strongly associated with active disease status (p < 0.0001), and correlated with global disease activity score (p < 0.0001) and anti-dsDNA Abs presence (p < 0.0001). The specificity of anti-C1q Abs was higher than anti-dsDNA (73% vs 19%) in discriminating LN patients, whereas the receiver operating characteristic curves were not statistically different (0.83 ± 0.06 vs 0.78 ± 0.08 respectively), similar to C3 dosage. The presence of anti-C1q Abs at diagnosis was not predictive for global or renal flare. Introduction of a modified SLEDAI score excluding dsDNA Abs, demonstrated a stronger correlation of anti-C1q Abs titres with SLEDAI score in comparison with the Farr test.

CONCLUSION

Anti-C1q Abs seem very specific to flares, including LN in children, and their role in daily practice compared with the Farr dsDNA assay needs to be defined.

Beneficial effect of magnolol on lupus nephritis in MRL/lpr mice by attenuating the NLRP3 inflammasome and NF‑κB signaling pathway: A mechanistic analysis

Lupus nephritis (LN) is a common complication of systemic lupus erythematosus. The present study aimed to elucidate the protective effect of magnolol (MG) on the progression of LN, via inhibition of key signaling pathways. The results of the present study demonstrated that administration of MG caused inhibition of the activation of NACHT, LRR and PYD domains‑containing protein 3 and interleukin‑1β production. Histopathological analysis confirmed that the vehicle‑treated group exhibited characteristic glomerular disease, which was observed to be suppressed following the administration of MG; a marked decrease in glomerular and vascular lesions was observed compared with the vehicle control. This decrease was further demonstrated through analysis of kidney sections. The expression level of cell surface glycoprotein F4/80 was demonstrated to be markedly decreased in the MG‑treated mice compared with the vehicle control group. The MG‑treated mice exhibited a marked decrease in serum and renal tumor necrosis factor‑α expression levels.

A Multicenter, Randomized, Double-Blind, Placebo-Controlled Study to Evaluate the Efficacy and Safety of Treatment With Sirukumab (CNTO 136) in Patients With Active Lupus Nephritis

Objective

To assess the efficacy and safety of sirukumab, an anti–interleukin‐6 monoclonal antibody, for the treatment of patients with active lupus nephritis (LN).

Methods

Patients with class III or class IV LN (as determined by renal biopsy within 14 months of randomization) who had persistent proteinuria (>0.5 gm/day) despite receiving immunosuppressive therapy and who were being treated with stable doses of a renin‐angiotensin system blocker were randomized (5:1) to receive treatment with sirukumab at a dose of 10 mg/kg intravenously (n = 21) or placebo (n = 4) every 4 weeks through week 24. The primary end point was the percent reduction in proteinuria (measured as the protein‐to‐creatinine [P:C] ratio in a 12‐hour urine collection) from baseline to week 24.

Results

Twenty‐five patients were enrolled, of whom 19 (76.0%) completed treatment through week 24 and 6 (24.0%) discontinued the study agent early, with 5 of the 6 discontinuing due to adverse events. At week 24, the median percent change in proteinuria from baseline to week 24 in sirukumab‐treated patients was 0.0% (95% confidence interval −61.8, 39.6). In contrast, the 4 placebo‐treated patients showed an increase in proteinuria (median percent reduction −43.3%) at week 24. Of note, a subset of 5 sirukumab‐treated patients had ≥50% improvement in their P:C ratio through week 28. In the sirukumab group, 47.6% of patients experienced ≥1 serious adverse event through week 40; most were infection‐related. No deaths or malignancies occurred. No serious adverse events were observed in the 4 placebo‐treated patients.

Conclusion

This proof‐of‐concept study did not demonstrate the anticipated efficacy nor did it demonstrate an acceptable safety profile for sirukumab treatment in this population of patients with active LN receiving concomitant immunosuppressive treatment.

Redefining lupus nephritis: clinical implications of pathophysiologic subtypes

Systemic lupus erythematosus (SLE) is associated with a broad spectrum of clinical and immunologic manifestations, of which lupus nephritis is the most common cause of morbidity and mortality. The development of nephritis in patients with SLE involves multiple pathogenic pathways including aberrant apoptosis, autoantibody production, immune complex deposition and complement activation. The 2003 International Society of Nephrology/Renal Pathology Society (ISN/RPS) classification system for lupus nephritis was widely accepted with high intraobserver and interobserver concordance to guide therapeutic strategy and provide prognostic information. However, this classification system is not based on the underlying disease pathophysiology. Some additional lesions that contribute to disease presentation, including glomerular crescents, podocyte injury, tubulointerstitial lesions and vascular injury, should be recognized. Although outcomes for patients with lupus nephritis have improved over the past 30 years, treatment of this disease remains challenging and is best approached on the basis of the underlying pathogenesis, which is only partially represented by the various pathological phenotypes defined by the ISN/RPS classification. Here, we discuss the heterogeneous mechanisms involved in the pathogenesis of lupus nephritis and how improved understanding of underlying disease mechanisms might help guide therapeutic strategies.

Research and therapeutics-traditional and emerging therapies in systemic lupus erythematosus

This review summarizes traditional and emerging therapies for SLE. Evidence suggests that the heterogeneity of SLE is a crucial aspect contributing to the failure of large clinical trials for new targeted therapies. A clearer understanding of the mechanisms driving disease pathogenesis combined with recent advances in medical science are predicted to enable accelerated progress towards improved SLE diagnosis and personalized approaches to treatment.

Improved strategies for designing lupus trials with targeted therapies: learning from 65 years of experience

The development of new agents to manage lupus erythematosus has lagged behind other autoimmune rheumatic diseases. This is in large part because lupus is a heterogeneous disorder affecting nine principal domains (organ systems) that are difficult to measure and quantify and can be at variance with each other. Over the last two decades, a variety of guidelines, definitions, candidate surrogate or biomarkers, metrics and composite indices have been presented as benchmarks that can be utilized to assess lupus in clinical trials. Despite this, over 20 agents have failed to achieve their primary outcome measure, some of which are generally believed to be clinically effective. This article presents constructive suggestions and improved strategies in trial design that will hopefully lead to the introduction of new agents for the disease.

Excessive activation of the TLR9/TGF-β1/PDGF-B pathway in the peripheral blood of patients with systemic lupus erythematosus

Background

Our aim is to study the existence of the TLR9/TGF-β1/PDGF-B pathway in healthy humans and patients with systemic lupus erythematosus (SLE), and to explore its possible involvement in the pathogenesis of lupus nephritis (LN).

Methods

Protein levels of the cytokines were detected by ELISA. mRNA levels of the cytokines were analyzed by real-time PCR. MTT assay was used to test the proliferation of mesangial cells under different treatments.

Results

Compared to healthy controls (N_Control = 56), levels of Toll-like receptor (TLR)9, transforming growth factor (TGF)-β1, and platelet-derived growth factor B (PDGF-B) were increased significantly in the peripheral blood of SLE patients (N_SLE = 112). Significant correlations between the levels of TLR9, TGF-β1, and PDGF-B were observed in both healthy controls and SLE patients. The levels of TGF-β1 and PDGF-B were greatly enhanced by TLR9 activation in primary cell cultures. The proliferation of mesangial cells induced by the plasma of SLE patients was significantly higher than that induced by healthy controls; PDGF-B was involved in this process. The protein levels of PDGF-B homodimer correlated with the levels of urine protein in SLE patients with LN (N_LN =38).

Conclusions

The TLR9/TGF-β1/PDGF-B pathway exists in humans and can be excessively activated in SLE patients. High levels of PDGF-B may result in overproliferation of mesangial cells in the kidney that are involved in the development of glomerulonephritis and LN. Further studies are necessary to identify TLR9, TGF-β1, and PDGF-B as new therapeutic targets to prevent the development of glomerulonephritis and LN.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-017-1238-8) contains supplementary material, which is available to authorized users.

Nephropathy in Pparg-null mice highlights PPARγ systemic activities in metabolism and in the immune system

Peroxisome proliferator-activated receptor γ (PPARγ) is a ligand-dependent transcription factor involved in many aspects of metabolism, immune response, and development. Total-body deletion of the two Pparg alleles provoked generalized lipoatrophy along with severe type 2 diabetes. Herein, we explore the appearance and development of structural and functional alterations of the kidney, comparing Pparg null-mice to their littermate controls (carrying Pparg floxed alleles). We show that renal hypertrophy and functional alterations with increased glucosuria and albuminuria are already present in 3 weeks-old Pparg null-mice. Renal insufficiency with decreased creatinine clearance progress at 7 weeks of age, with the advance of the type 2 diabetes. At 52 weeks of age, these alterations are accompanied by signs of fibrosis and mesangial expansion. More intriguingly, aged Pparg null-mice concomitantly present an anti-phospholipid syndrome (APS), characterized by the late appearance of microthrombi and a mesangioproliferative pattern of glomerular injury, associated with significant plasmatic levels of anti-β2- glycoprotein1 antibodies and renal deposition of IgG, IgM, and C3. Thus, in line with the role of PPARγ in metabolic homeostasis, Pparg null-mice first represent a potent model for studying the initiation and the development of diabetic nephropathy. Second, and in relation with the important PPARγ activity in inflammation and in immune system, these mice also highlight a new role for PPARγ signaling in the promotion of APS, a syndrome whose pathogenesis is poorly known and whose current treatment is limited to prevention of thrombosis events.

CCL2 deficient mesenchymal stem cells fail to establish long-lasting contact with T cells and no longer ameliorate lupus symptoms

Systemic lupus erythematosus (SLE) is a multi-organ autoimmune disease characterized by autoantibody production. Mesenchymal stem cells (MSCs) ameliorate SLE symptoms by targeting T cells, whereas the mechanisms of their efficacy remain incompletely understood. In this study, we show that transfer of human MSCs increased MRL.Fas^lpr mouse survival, decreased T cell infiltration in the kidneys, and reduced T cell cytokine expression. In vitro, allogeneic mouse MSCs inhibited MRL.Fas^lpr T cell proliferation and cytokine production. Time-lapse imaging revealed that MSCs recruited MRL.Fas^lpr T cells establishing long-lasting cellular contacts by enhancing T cell VCAM-1 expression in a CCL2-dependent manner. In contrast, CCL2 deficient MSCs did not induce T cell migration and VCAM-1 expression, resulting in insufficient cell-cell contact. Consequently, CCL2 deficient MSCs did not inhibit IFN-γ production by T cells and upon transfer no longer prolonged survival of MRL.Fas^lpr mice. Taken together, our imaging study demonstrates that CCL2 enables the prolonged MSC-T cell interactions needed for sufficient suppression of autoreactive T cells and helps to understand how MSCs ameliorate symptoms in lupus-prone MRL.Fas^lpr mice.

Effect of Rituximab on Serum Levels of Anti-C1q and Antineutrophil Cytoplasmic Autoantibodies in Refractory Severe Lupus Nephritis

The objective of this study was to analyze and compare the effects of rituximab (RTX) and cyclophosphamide (CTX) on the serum levels of anti-C1q antibodies and antineutrophil cytoplasmic autoantibodies (ANCA) in assessing the prognosis of severe and refractory lupus nephritis (LN). Eighty-four cases of severe and refractory LN were randomly divided into two groups of 42 cases each: CTX group and RTX group (CTX+RTX) during February 2010 to February 2014 in our hospital. Changes in serum levels of anti-C1q antibodies and ANCA in the two groups were examined, and efficacies of the drugs were compared. The total efficacy of RTX group was found to be 83.3 %, which was significantly higher than that of the CTX group, 57.1 % (p < 0.05). The serum anti-C1q antibodies and ANCA were decreased to 11.9 and 26.2 % in the RTX-treated group, which was significantly lower than those observed in the CTX-treated patients (21.4 and 69.0 % respectively) (p < 0.05). The clinical indices of LN were significantly improved in the two groups after the treatment. However, the urinary protein, albumin, complement C3, the percentage of CD19(+)B cells, and SLEDAI scores in the RTX group were significantly lower than those in the CTX group (p < 0.05). RTX plus with CTX showed a better therapeutic efficacy compared to CTX, and it significantly improved the prognosis of refractory and severe LN. The improvement in disease prognosis was directly related to the reduced serum levels of anti-C1q and ANCA measured during the course of treatment suggesting that they can serve to be valuable biomarkers of LN prognosis. Moreover, the measurement can assist in the judgment of RTX efficacy guiding the adjustment of the drug dose to improve the quality of life.

Reno-protective effect and mechanism study of Huang Lian Jie Du Decoction on lupus nephritis MRL/lpr mice

BACKGROUND

Huang Lian Jie Du Decoction (HLJDD), a very famous traditional Chinese medicinal prescription, has been used for heat dissipation and detoxification in China. This study was aimed to evaluate the reno-protective effects of HLJDD against lupus nephritis (LN) in vivo in MRL/lpr mice.

METHODS

Animals were administered orally every day for eight consecutive weeks except the mice of normal group and model group. Organ indexes, serum interleukin-6 (IL-6), interleukin-10 (IL-10), interferon-gamma (IFN-γ) and the anti-double stranded DNA (anti-dsDNA) antibody were tested, respectively. Creatinine (Cr), blood urea nitrogen (BUN) and urine protein were measured for renal function evaluation. The expression of phosphorylated signal transducer and activator of transcription 3 (p-STAT 3) in kidney tissue was observed by western blot (WB) and immunohistochemical (IHC) method. Meanwhile, histopathological changes in the renal were studied by hematoxylin-eosin (H&E) staining.

RESULTS

The mice of HLJDD-treated group exhibited a significant reduced mortality (p < 0.05), serum anti-dsDNA level (p < 0.05) and renal immune complex deposition (p < 0.05), compared with the untreated MRL/lpr mice. In addition, HLJDD treatment remarkably reduced the levels of BUN, Cr, proteinuria (p < 0.01) and the levels of inflammatory cytokines such as IL-6, IL-10 and IFN-γ (p < 0.01). Moreover, HLJDD significantly suppressed the phosphorylations of STAT 3 (p < 0.05) and the renal pathological changes.

CONCLUSIONS

The study implied that HLJDD may be a potential agent for the therapy of LN, and the down-regulated p-STAT 3 expression suggesting that it may be one of the LN therapy targets for HLJDD.

Lupus nephritis in children - 10 years' experience

Systemic lupus erythematosus (SLE) in children is usually more severe than it is in adults and there is a higher incidence of renal involvement. We described 18 children (16 girls, 2 boys) with lupus nephritis (LN), whose average age was 14.4 ±1.81 years. Disease activity was assessed according to SLEDAI (SLE Disease Activity Index). Renal biopsy was classified according to the INS/RPS (International Society of Nephrology/Renal Pathology Society). The patients were treated with steroids (100%) and pulses of cyclophosphamide (88.9%) or mycophenolate mofetil (11.1%), next azathioprine or mycophenolate mofetil with prednisone in reduced doses. In children with renal/multi-organ insufficiency and/or septicaemia, renal replacement therapy (27.8%), and plasmapheresis (22.2%) were used in the initial treatment. The SLEDAI initial activity was high in 44.4% and moderate in 55.6% of children. LN manifested as: nephrotic syndrome (83.3%), microhaematuria (100%), leukocyturia (60%), hypertension (72.2%), and acute renal injury (83.3%); mean GFR was 54.55 ±33.09 ml/min/1.73 m². In the renal biopsy, class IV LN according to INS/RPS was mainly diagnosed (82%). At the end of follow-up, mean observation time 32.1±23.36 months: mean GFR was 90.87 ±12.13 ml/min/1.73 m², proteinuria disappeared in 66.7% and decreased in 33.3% of children to the average of 1.7 g/day (range: 0.5-4.0 g/day), hypertension was observed in 83.4% of children. Intensive immunosuppressive treatment with pulses of cyclophosphamide in early stage of LN in children is very effective.

Genetics of Lupus Nephritis: Clinical Implications

Systemic lupus erythematosus is a heterogeneous autoimmune disease marked by the presence of pathogenic autoantibodies, immune dysregulation, and chronic inflammation that may lead to increased morbidity and early mortality from end-organ damage. More than half of all systemic lupus erythematosus patients will develop lupus nephritis. Genetic-association studies have identified more than 50 polymorphisms that contribute to lupus nephritis pathogenesis, including genetic variants associated with altered programmed cell death and defective immune clearance of programmed cell death debris. These variants may support the generation of autoantibody-containing immune complexes that contribute to lupus nephritis. Genetic variants associated with lupus nephritis also affect the initial phase of innate immunity and the amplifying, adaptive phase of the immune response. Finally, genetic variants associated with the kidney-specific effector response may influence end-organ damage and the progression to end-stage renal disease and death. This review discusses genetic insights of key pathogenic processes and pathways that may lead to lupus nephritis, as well as the clinical implications of these findings as they apply to recent advances in biologic therapies.

Antiphospholipid Syndrome and the Kidney

The antiphospholipid syndrome (APS) is a systemic autoimmune disorder characterized by a combination of arterial and/or venous thrombosis, pregnancy morbidity, and the persistent presence of circulating antiphospholipid antibodies (aPL). APS has been described as primary APS when it occurs in the absence of any features of other autoimmune disease, and as secondary in the presence of other autoimmune diseases, mainly systemic lupus erythematosus (SLE). There is a well-known link between SLE and APS; 40% of SLE patients have aPL, and, in turn, some, but only a minority of patients with APS, eventually will develop features of SLE. Because SLE and APS can target the kidneys independently or at the same time, discriminating between inflammatory or thrombotic lesions is crucial in planning therapy. We provide an overview of the renal manifestations associated with the presence of aPL in patients with SLE, and discuss the impact of aPL in selected scenarios such as lupus nephritis, end-stage renal disease, and pregnancy.

A pathophysiology-based approach to the diagnosis and treatment of lupus nephritis

Lupus is no longer an unknown chameleon of medicine. Significant progress has been made on unraveling the pathogenesis of lupus and lupus nephritis, and how to treat the disease. Here we provide an update on the pathophysiology of lupus and its related kidney disease, consider areas of controversy in disease management, and discuss the unmet needs of lupus nephritis and how to address these needs. We focus on rethinking how innovative therapies for lupus nephritis should be evaluated and evolving strategies to more efficiently mitigate irreversible nephron loss in patients with lupus nephritis.