Renal microvascular lesions in lupus nephritis

Vascular injury in glomerulopathies: the role of the endothelium

In glomerulopathies, endothelial dysfunction and the presence of histological vascular lesions such as thrombotic microangiopathy, arteriolar hyalinosis, and arteriosclerosis are related to a severe clinical course and worse renal prognosis. The endothelial cell, which naturally has anti-inflammatory and anti-thrombotic regulatory mechanisms, is particularly susceptible to damage caused by various etiologies and can become dysfunctional due to direct/indirect injury or a deficiency of protective factors. In addition, endothelial regulation and protection involve participation of the complement system, factors related to angiogenesis, the renin-angiotensin system (RAS), endothelin, the glycocalyx, the coagulation cascade, interaction between these pathways, interactions between glomerular structures (the endothelium, mesangium, podocyte, and basement membrane) and interstitial structures (tubules, arterioles and small vessels). Dysregulation of those components is also associated with the progression of renal fibrosis, since endothelial cell damage promotes endothelial-to-mesenchymal transition. Although the potential mechanisms of vascular injury have been widely described in diabetic kidney disease, hypertensive nephrosclerosis, and hemolytic uremic syndrome, they require further elucidation in other glomerulopathies. A better understanding of the pathogenesis of vascular injury in patients with glomerular diseases could contribute to the development of specific treatments for such injury.

Graft survival and mortality outcomes after kidney transplant in patients with lupus nephritis: a systematic review and meta-analysis

To explore the effect of lupus nephritis (LN) on graft survival in renal transplant patients. Literature search was conducted in PubMed, EMBASE and Scopus database for randomized controlled trials (RCTs), cohort, and case-control studies. The target population of interest was adult patients (aged >18 years) with end-stage renal disease (ESRD) and no history of previous renal transplants. Primary outcomes of interest were graft survival and patient survival. Pooled effect estimates were calculated using random-effects models and reported as hazard ratio (HR) with 95% confidence intervals (CI). A total of 15 studies were included. Compared to patients with ESRD due to other causes, patients with LN undergoing kidney transplant had lower patient survival rate (HR 1.15, 95% CI: 1.01, 1.31; N = 15, I2=34.3%) and worse graft survival (HR 1.06, 95% CI: 1.01, 1.11; N = 16, I2=0.0%), especially when studies with deceased donor were pooled together. Studies with a larger sample size (>200) showed that LN was strongly associated with lower graft and patient survival rates. Elevated risk of mortality in LN patients was detected in case-control studies, but not RCTs. On the other hand, RCTs, but not case-control studies, showed an increased risk of poor graft survival in LN patients. The findings suggest that the presence of LN might have a negative impact on both the graft survival and the overall patient survival of post-transplant ESRD patients. Further studies that account for factors such as study methodology, donor characteristics, and sample size are needed to reach definitive conclusions. Renal transplant patients with LN should undergo regular follow-up examinations.

Beyond the lungs: Exploring diverse applications of bromhexine and ambroxol

The respiratory tract is commonly affected in multisystem disorders. Although many drugs have been developed to target various components of these diseases, there is still a need for effective treatments that can address both respiratory and non-respiratory symptoms. Bromhexine and ambroxol are mucolytic agents with a good safety profile that are widely used to treat respiratory conditions. These compounds seem to present several unresolved questions when carrying out their therapeutic effects, suggesting that they may not merely improve mucociliary clearance. These assumptions have provided the basis for researchers to investigate the specific characteristics of bromhexine and ambroxol. This has led to the emergence of several repositionings for this compound. Accordingly, these compounds have also shown potential benefits in the treatment of various extrapulmonary disorders, including neurological disorders, and inflammatory bowel disease. We gathered findings from relevant studies published in English between 1970 and December 2023 by searching databases including PubMed, Google Scholar, Scopus, Embase, and the Cochrane Library. Our findings revealed that most of the research on extrapulmonary uses has been conducted at the preclinical level. Accordingly, more clinical studies are needed to determine the effectiveness of bromhexine and ambroxol in these conditions. This article provides an overview of the potential extrapulmonary applications of bromhexine and ambroxol and discusses the potential advantages of using these drugs in multisystem disorders.

Threonine Phosphorylation and the Yin and Yang of STAT1: Phosphorylation-Dependent Spectrum of STAT1 Functionality in Inflammatory Contexts

Threonine phosphorylation promotes inflammatory functions of STAT1 while restricting its interferon (IFN) signaling in innate immune responses. However, it remains unclear whether the restriction of STAT1-mediated IFN signaling conferred by threonine phosphorylation is a ubiquitous mechanism or one that is context-dependent. To address this, we utilized pristane-induced lupus, a prototype IFN-driven systemic autoimmune disease model characterized by the production of high-titer autoantibodies against nucleic acid-associated antigens. Through genetic and biochemical assays, we demonstrate that Thr748 phosphorylation is dispensable for STAT1 functionality in pristane-induced lupus. Genetically engineered mice expressing the phospho-deficient threonine 748-to-alanine (T748A) mutant STAT1 exhibited similar survival rates, high titers of anti-dsDNA IgG, and nephritis compared to their wild-type littermates. In sharp contrast, STAT1 deficiency protected mice against pristane-induced lupus, as evidenced by increased survival, low titers of anti-dsDNA IgG, and less severe nephritis in the STAT1 knockout mice compared to their T748A littermates. Our study suggests a phosphorylation-dependent modularity that governs the spectrum of STAT1 functionality in inflammatory contexts: IFN phospho-tyrosine-dependent and inflammatory phospho-threonine-dependent, with Thr748 phosphorylation driving selective inflammatory activities, particularly those not driven by the canonical JAK pathway. From a broader perspective, our findings provide deeper insights into how distinct phosphorylation events shape the combinatorial logic of signaling cassettes, thereby regulating context-dependent responses.

[Lupus nephritis and thrombotic microangiopathy: A review]

Lupus nephritis (LN) is one of the most common organ-specific manifestations of systemic lupus erythematosus (SLE). Various clinical signs of LN develop in at least 50% of patients with SLE. In addition to LN, the spectrum of renal lesions associated with SLE also includes vascular pathology. One of the variants of renal microvascular injury is thrombotic microangiopathy (TMA), the mechanisms of which are diverse. The review focuses on the main forms of TMA, including antiphospholipid syndrome and nephropathy associated with antiphospholipid syndrome, TMA caused by complement system regulation disorders and deficiency of ADAMTS13. In most cases, these forms of TMA are combined with LN. However, they may also exist as a single form of kidney damage. This article discusses the TMA pathogenesis, the impact on kidney prognosis, and treatment options.

Risk Factors and Clinical Outcomes of Renal Thrombotic Microangiopathy in Children with Lupus Nephritis in Terms of Pathological and Clinical Features

BACKGROUND

Thrombotic microangiopathy (TMA) is an important risk factor for the prognosis of lupus nephritis (LN). Patients with LN complicated with TMA tend to be critically ill with high mortality and poor prognosis. In the present study, we retrospectively analyzed the clinical manifestations, laboratory results, renal pathological manifestations, and prognosis of children with LN-TMA and analyzed the risk factors for end-stage renal disease (ESRD) in children with LN-TMA.

METHODS

Seventy-four patients with LN and renal TMA (rTMA) were selected and compared to 128 LN controls without TMA (1:2 ratio) matched according to demographics, pathological type and treatments.

RESULTS

The mean values of systolic blood pressure, diastolic blood pressure (DBP), lactate dehydrogenase (LDH), blood urea nitrogen (BUN), urinary protein quantitation (PRO), urine red blood cells, N-acetyl-β-D-glucosidase (NAG), retinol-binding protein, systemic lupus erythematosus disease activity score (SLEDAI), and activity index (AI) scores in the TMA group were all higher than those in the non-TMA group (p < 0.05 and p < 0.01). The mean values of complement C3, hemoglobin, platelets, estimated glomerular filtration rate, and chronic index (CI) score in the TMA group were all lower than those in the non-TMA group (p < 0.05 and p < 0.01). The number of cases of glomerular crescent, fibrous crescent, endocapillary proliferation, tubular atrophy, interstitial fibrosis, C3 and C1q deposition in the TMA group was higher than that in the non-TMA group (p < 0.05 and p < 0.01). The 3-year and 5-year renal survival rates in the TMA group (88.93% vs. 97.00%, p < 0.05) and TMA group (61.41% vs. 82.31%, p < 0.05) were significantly lower than those in the non-TMA group. Multivariate Cox regression analysis showed that serum creatinine before treatment (≥110 μmol/L), TMA and interstitial fibrosis were independent risk factors for the development of ESRD in LN children.

CONCLUSION

The general condition of children with TMA is critical, and the prognosis is poor. Early detection, early treatment and the development of new treatments are key to improving LN-TMA outcomes in children.

Implications of Inflammatory Processes on a Developing Central Nervous System in Childhood-Onset Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease that is increasingly affecting pediatric and adult populations. Neuropsychiatric manifestations (ie, cognitive dysfunction and mood disorders) appear to occur with greater severity and poorer prognosis in childhood-onset SLE (cSLE) versus adult-onset SLE, negatively impacting school function, self-management, and psychosocial health, as well as lifelong health-related quality of life. In this review, we describe pathogenic mechanisms active in cSLE, such as maladaptive inflammatory processes and ischemia, which are hypothesized to underpin central phenotypes in patients with cSLE, and the role of alterations in protective central nervous system (CNS) barriers (ie, the blood-brain barrier) are also discussed. Recent findings derived from novel neuroimaging approaches are highlighted because the methods employed in these studies hold potential for identifying CNS abnormalities that would otherwise remain undetected with conventional multiple resonance imaging studies (eg, T2-weighted or fluid-attenuated inversion recovery sequences). Furthermore, we propose that a more robust presentation of neuropsychiatric symptoms in cSLE is in part due to the harmful impact of a chronic inflammatory insult on a developing CNS. Although the immature status of the CNS may leave patients with cSLE more vulnerable to harboring neuropsychiatric manifestations, the same property may represent a greater urgency to reverse the maladaptive effects associated with a proneuroinflammatory state, provided that effective diagnostic tools and treatment strategies are available. Finally, considering the crosstalk among the CNS and other organ systems affected in cSLE, we postulate that a finer understanding of this interconnectivity and its role in the clinical presentation in cSLE is warranted.

[Clinical characteristics and prognosis of 12 cases of lupus nephritis complicated with thrombotic microangiopathy]

OBJECTIVES

To investigate the clinical characteristics, pathological features, treatment regimen, and prognosis of children with lupus nephritis (LN) and thrombotic microangiopathy (TMA), as well as the treatment outcome of these children and the clinical and pathological differences between LN children with TMA and those without TMA.

METHODS

A retrospective analysis was conducted on 12 children with LN and TMA (TMA group) who were admitted to the Department of Nephrology, Children's Hospital of Nanjing Medical University, from December 2010 to December 2021. Twenty-four LN children without TMA who underwent renal biopsy during the same period were included as the non-TMA group. The two groups were compared in terms of clinical manifestations, laboratory examination results, and pathological results.

RESULTS

Among the 12 children with TMA, 8 (67%) had hypertension and 3 (25%) progressed to stage 5 chronic kidney disease. Compared with the non-TMA group, the TMA group had more severe tubulointerstitial damage, a higher Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) score at onset, and higher cholesterol levels (P<0.05). There were no significant differences between the two groups in the percentage of crescent bodies and the levels of hemoglobin and platelets (P>0.05).

CONCLUSIONS

There is a higher proportion of individuals with hypertension among the children with LN and TMA, as well as more severe tubulointerstitial damage. These children have a higher SLEDAI score and a higher cholesterol level.

Research progress in functional magnetic resonance imaging assessment of lupus nephritis kidney injury

Lupus nephritis is one of the most common and severe complications of systemic lupus erythematosus and is also a major predictor of poor prognosis and mortality. Lupus nephritis has the characteristics of insidious onset, complex pathological types, rapid progression of organ damage, and easy recurrence. Currently, kidney damage in lupus nephritis is usually assessed based on urine analysis, renal biopsy, and glomerular filtration rates. However, they all have certain limitations, making it difficult to diagnose lupus nephritis early and assess its severity and progression. With the rapid development of functional magnetic resonance, multiple functional imaging techniques are expected to provide more useful information for the pathophysiological development, early diagnosis, progression, prognosis, and renal function evaluation of lupus nephritis. This article reviews the principle of multiple functional magnetic resonance imaging and the research status of evaluating renal function in lupus nephritis.

Anti-C1q antibodies in lupus nephritis children with glomerular microthrombosis

AIM

Glomerular microthrombosis (GMT) was a common vascular lesion in patients with lupus nephritis (LN). The objective of this study was to investigate the relationship between serum anti-beta2-glycoprotein I antibodies (a-β2GP1) and anti-complement 1q antibodies (a-C1q) antibodies and to investigate the possible mechanism of GMT in children with LN.

METHODS

The subjects were 191 children with LN diagnosed by renal biopsy in our hospital from January 2017 to January 2020. The patients were divided into GMT group and non-GMT group. The clinical manifestations, laboratory tests, renal pathology, prognosis of the two groups and the relationship between a-β2GP1 and a-C1q antibodies were observed.

RESULTS

In 191 children with LN, 52 cases (27.23%) presented with GMT. The value of C3, haemoglobin (Hb), estimate glomerular filtration rate (eGFR) and anticardiolipin antibody (ACA) in GMT group were lower than that of non-GMT group (p < .05, p < .01). The value of serum creatinine (Scr), 24 h proteinuria (PRO), urine red blood cells (RBC), N-acetyl-β-d-glucosidase (NAG) and retinol-binding protein (RBP), a-C1q, a-β2GP1, Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) and renal histopathological activity index (AI) score in GMT group were higher than that of non-GMT group (p < .05, p < .01). The positive proportions of serum a-C1q and a-β2GP1 in GMT group were higher than those in non-GMT group (p < .05). According to Spearman correlation analysis, a-C1q was positively correlated with AI score, SLEDAI, a-β2GP1, GMT, LN-III and LN-IV. Hb, eGFR and a-C1q Ab were associated with the formation of GMT in children with LN. The complete proteinuria remission and renal survival in GMT group were significantly lower than those in non-GMT group (p < .05, p < .01).

CONCLUSION

LN children with GMT had more severe clinical manifestations and renal pathologic damages, and poor outcome. Serum a-C1q level was positively correlated with a-β2GP1, and a-β2GP1 may be involved in the formation of GMT in children with LN, which might involve in the activation of complement classical pathway.

Challenging diagnosis of renal failure associated with severe neurological symptoms in a patient with mixed connective tissue disease

We report the case of a patient followed for a mixed connective tissue disease with signs of systemic sclerosis and systemic lupus, who presented an acute renal failure with severe neurological symptoms (confusion, obnubilation) and hypertension. The distinction between scleroderma renal crisis and lupus nephritis was challenging and hence, the decision to use or not high dose of corticosteroids. Kidney biopsy was of major importance for the diagnosis and therapeutic strategy. The diagnosis of neurological symptoms was also made difficult given the clinical presentation and the results of imaging. Neurolupus, malignant hypertension, or posterior reversible encephalopathy syndrome were the evoked diagnosis.

Thrombotic microangiopathy mediates poor prognosis among lupus nephritis via complement lectin and alternative pathway activation

Objective

The pathogenesis of thrombotic microangiopathy (TMA) in lupus nephritis (LN) remains complicated. This study aimed to detect the deposition of complement lectin pathway (LP) and alternative pathway (AP) components in renal tissues, then evaluate the clinicopathological characteristics and risk factors for renal survival between patients with or without TMA in LN cohorts.

Methods

We included 79 patients with biopsy-proven LN-associated TMA and matched the same number of LN patients without TMA as the control group. The deposition of mannose binding lectin (MBL), MBL-associated serine proteases 1/3 (MASP1/3), complement factor B (CFB), complement factor D (CFD), C4d, and von Willebrand factor (VWF) in renal tissue was assessed by immunohistochemistry and immunofluorescence. Besides, co-localization of C5b-9 and CD34 was detected by confocal microscopy.

Results

In our retrospective cohort, the incidence of acute kidney injury (30% vs. 14%, p = 0.013), acute hemodialysis (35% vs. 5%, p < 0.001), and interstitial fibrosis (43% vs. 13%, p < 0.001) is higher in the TMA, compared with the control group. Despite aggressive steroids pulse, plasma exchange, and immunosuppressive therapy among TMA group, they still had significantly inferior 3-year renal survival rates (68% vs. 89%, p = 0.002) than those in the non-TMA group. COX regression analysis identified that TMA (HR 4.807, 95% CI [2.052, 11.263], p < 0.001) is a risk factor in LN. MBL, MASP1/3, CFB, CFD, C4d, and VWF deposited along the glomerulus among LN, while TMA had stronger staining intensity and deposition. The co-localized expression of CD34 and C5b-9 in the endothelial cells was also observed in the renal tissues.

Conclusions

TMA is an independent risk factor for renal survival in LN patients. Moreover, LP and AP activation are involved in the pathogenesis of LN-associated TMA.

Anti-galectin-3 antibodies induce skin vascular inflammation via promoting local production of IL-1β in systemic lupus erythematosus

Vascular inflammation could occur in all organs and tissues in patients with systematic lupus erythematosus (SLE), of which skin is the most frequent one. Our previous research identified anti-galectin-3 (Gal3) antibodies (Abs) as an important mediator of lupus cutaneous vasculopathy. Herein, we showed that anti-Gal3 Abs dysregulated the function of vascular endothelial cells with higher transcript levels of IL-1β and increased expression of mature IL-1β. The enhanced production of IL-1β secreted by endothelial cells was dependent on NLRP3 inflammasome. Intradermal injection of anti-Gal3 Abs in mice induced local inflammation with perivascular infiltration of T cells and neutrophils, which was inhibited by IL-1β blockade. Induction of anti-Gal3 Abs in circulation by immunization of Gal3 antigen not only led to histopathologic changes in the skin, including focal keratinocytes vacuolization and thickening of blood vessels, but also a systemic autoimmune phenotype that involves autoantibody production and kidney damage. Intriguingly, local overexpression of IL-1β was primarily associated with skin lesions but not with other internal organs in mice. Finally, we showed that the serum levels of IL-1β were comparable between SLE patients and healthy donors. Whilst the expression of IL-1β was enriched in local area with perivascular inflammation in lupus skin lesion compared to healthy normal skin. The results strongly suggest that IL-1β plays an important role in mediating anti-Gal3 Ab-induced skin vascular inflammation and raised the prospect for using IL-1β blocking therapies to treat lupus cutaneous damage.

Intrarenal Single-Cell Sequencing of Hepatitis B Virus Associated Membranous Nephropathy

To date, the pathogenesis of hepatitis B virus (HBV)-associated membranous nephropathy (MN) remains elusive. This study aimed to decipher the etiopathogenesis of HBV-associated MN by performing single-cell RNA sequencing (scRNA-seq) of kidney biopsy specimens from a patient with HBV-associated MN and two healthy individuals. We generated 4,114 intrarenal single-cell transcriptomes from the HBV-associated MN patient by scRNA-seq. Compared to healthy individuals, podocytes in the HBV-associated MN patient showed an increased expression of extracellular matrix formation-related genes, including HSPA5, CTGF, and EDIL3. Kidney endothelial cells (ECs) in the HBV-associated MN were enriched in inflammatory pathways, including NF-kappa B signaling, IL-17 signaling, TNF signaling and NOD-like receptor signaling. Gene ontology (GO) functional enrichment analysis and Gene Set Variation Analysis (GSVA) further revealed that differentially expressed genes (DEGs) of ECs from the HBV-associated MN patients were enriched in apoptotic signaling pathway, response to cytokine and leukocyte cell-cell adhesion. The up-regulated DEGs in glomerular ECs of HBV-associated MN patients were involved in biological processes such as viral gene expression, and protein targeting to endoplasmic reticulum. We further verified that the overexpressed genes in ECs from HBV-associated MN were mainly enriched in regulation of protein targeting to endoplasmic reticulum, exocytosis, viral gene expression, IL-6 and IL-1 secretion when compared with anti-phospholipase A2 receptor (PLA2R)-positive idiopathic membranous nephropathy (IMN). The receptor-ligand crosstalk analysis revealed potential interactions between endothelial cells and other cells in HBV-associated-MN. These results offer new insight into the pathogenesis of HBV-associated MN and may identify new therapeutic targets for HBV-associated MN.

Long-term outcome and predictors of long-term outcome in patients with lupus nephritis managed at a tertiary hospital in Mumbai

AIM

Study the long-term outcome of the patients with LN and identify the baseline factors that can predict the long-term outcome of these patients.

METHODS

All biopsy-proven LN patients who attended our regular 'lupus nephritis' clinic from 2013 to 2021 were studied. Data of these patients were collected from the hospital patient records. Standard therapy was given as per the KDIGO guidelines, and the renal response was evaluated according to KDIGO outcome criteria. Cox' regression analysis was used to determine predictors of chronic kidney disease (persistent doubling of serum creatinine with creatinine ≥1.5 mg%). Kaplan-Meier analysis was used for renal survival.

RESULTS

Eighty patients with at least 1 year of follow-up were included. Median age of onset was 24 years (IQR18-35). Median follow up was 6.5 years (IQR 3-10). World Health Organisation renal biopsy profile was Class I 1(1.2 %), Class II 6(7.5 %), Class III 9(11.2 %), Class IV 36(45 %), Class V 18(22.5 %) and Mixed Class IV + V 10 (12%). Complete remission was achieved in 63.75%, 70 % and 66.6% patients at 1, 2 and 5 years, respectively. Survival with normal renal function was 88.5 %, 85.8% and 60 % at 5, 10 and 15 years, respectively. Risk factors for poor outcome on univariate analysis were presence of Raynaud's phenomena-hazard ratio(HR) 7.78 (CI 1.944-31.207; p < .004), baseline hypertension-HR 5.356 (CI 1.479-19.403; p < .011), tubulointerstitial involvement-HR 1.076 (CI 1.032-1.222; p < .001), time to complete response-HR 1.036 (CI 1.036-1.067; p < .02 ), serum creatinine at 6 months HR 10.51 (CI 2.19-50.39; p < .003), failure to achieve complete response at 2 years HR 6.271 (CI 1.567-25.092; p < .009) and the number of nephritic flares HR 1.868(CI 1.103-3.164 ; p < .02). Renal relapses were quite common, with 1.8 flares per 10 patient-years of follow up. Infection was the most common cause of death, with bacterial lower respiratory infections and pulmonary tuberculosis being the most common.

CONCLUSIONS

Apart from conventional risk factors, other predictive factors like the presence of Raynaud's phenomenon, tubulointerstitial fibrosis and tubular atrophy on kidney biopsy, and initial response to induction therapy by 6 months have a significant impact on the long-term outcome in patients with LN.

Connexin 43 Expression in Cutaneous Biopsies of Lupus Erythematosus

INTRODUCTION

Gap junctions are channels between adjacent cells formed by connexins (Cxs). Cxs also form hemichannels that connect the cell with its extracellular milieu. These channels allow the transport of ions, metabolites, and small molecules; therefore, Cxs, and more specifically, connexin (Cx) 43 has been demonstrated to be in control of several crucial events such as inflammation and cell death.

MATERIAL AND METHODS

We examined the immunostaining of Cx43 in the endothelia of the cutaneous blood vessels of biopsies from 28 patients with several variants of lupus erythematosus.

RESULTS

In 19 cases (67.86%), staining of more than half of the dermal vessels including both vessels of the papillary and of the reticular dermis was identified. Only in 4 cases (14.28%), less than 25% of the vessels in the biopsy showed expression of the marker.

CONCLUSIONS

Our results suggest a role of Cx43 in regulating the endothelial activity in lupus erythematosus, which also opens a door for targeted therapeutic options.

Potential Small Molecules for Therapy of Lupus Nephritis Based on Genetic Effect and Immune Infiltration

Lupus nephritis (LN) is the most common and significant complication of systemic lupus erythematosus (SLE) due to its poor prognosis and mortality rates in SLE patients. There is a critical need for new drugs as the pathogenesis of LN remains to be elucidated and immunosuppressive therapy comes with many deficiencies. In this study, 23 hub genes (IFI6, PLSCR1, XAF1, IFI16, IFI44, MX1, IFI44L, IFIT3, IFIT2, IFI27, DDX58, EIF2AK2, IFITM1, RTP4, IFITM3, TRIM22, PARP12, IFIH1, OAS1, HERC6, RSAD2, DDX60, and MX2) were identified through bioinformatics and network analysis and are closely related to interferon production and function. Interestingly, immune cell infiltration analysis and correlation analysis demonstrate a positive correlation between the expression of 23 hub genes and monocyte infiltration in glomeruli and M2 macrophage infiltration in the tubulointerstitium of LN patients. Additionally, the CTD database, DsigDB database, and DREIMT database were used to explore the bridging role of genes in chemicals and LN as well as the potential influence of these chemicals on immune cells. After comparison and discussion, six small molecules (Acetohexamide, Suloctidil, Terfenadine, Prochlorperazine, Mefloquine, and Triprolidine) were selected for their potential ability in treating lupus nephritis.

Renal manifestations of paediatric systemic lupus erythematosus

PURPOSE OF REVIEW

Systemic lupus erythematosus is a lifelong, multisystemic disease. Around a fifth of patients present during childhood. Children are recognized to have a more active disease course with more renal involvement (lupus nephritis) when compared with adults. This review article summarizes the current literature surrounding the management of paediatric lupus nephritis.

RECENT FINDINGS

International recommendations agree that active, proliferative forms of lupus nephritis are treated with a period of intense induction therapy aimed at inducing remission followed by maintenance immunosuppressive therapy for at least 3 years. Complete response rates in lupus nephritis remain inadequate, in the region of 40-60%, and disease flares are common. Revised histological classification have been proposed but they are yet to be adopted in clinical practice. Lupus nephritis progresses to chronic kidney disease (CKD) stage 5 (kidney failure) in more than 10% of patients within 10 years however the rates of CKD stages 1-4 remain largely unknown. Current trials are focused on the use of biologic agents as adjuncts to current therapy.

SUMMARY

There is an urgent need for better outcomes in paediatric lupus nephritis. The use of biomarkers to monitor lupus nephritis and scientific studies to improve our understanding of the pathogenesis offer hope of improved outcomes.

Immunosenescence: an unexplored role in glomerulonephritis

Immunosenescence is a natural ageing phenomenon with alterations in innate and especially adaptive immunity and contributes to reduced antimicrobial defence and chronic low‐grade inflammation. This is mostly reflected by an increase in organ‐directed and/or circulating reactive and cytolytic terminally differentiated T cells that have lost their expression of the costimulatory receptor CD28. Apart from being induced by a genetic predisposition, ageing or viral infections (particularly cytomegalovirus infection), immunosenescence is accelerated in many inflammatory diseases and uraemia. This translates into an enhancement of vascular inflammation and cardiovascular disease varying from endothelial dysfunction to plaque rupture. Emerging data point to a mechanistic role of CD28^null T cells in glomerulonephritis, where they initiate and propagate local inflammation in concordance with dendritic cells and macrophages. They are suitably equipped to escape immunological dampening by the absence of homing to lymph nodes, anti‐apoptotic properties and resistance to suppression by regulatory T cells. Early accumulation of senescent CD28^null T cells precedes glomerular or vascular injury, and targeting these cells could open avenues for early treatment interventions that aim at abrogating a detrimental vicious cycle.

Effect of sera from lupus patients on the glomerular endothelial fibrinolysis system

BACKGROUND

Dysregulation of the coagulation fibrinolysis system in resident glomerular cells is associated with the pathogenesis of lupus nephritis. However, the role of plasminogen activator inhibitor-1 (PAI-1) and tissue plasminogen activator (tPA) in resident glomerular cells remains undetermined.

METHODS

We examined the expression of PAI-1 and tPA mRNA in cultured normal human glomerular endothelial cells (GECs) treated with serum from patients with systemic lupus erythematosus (SLE) using quantitative reverse transcription polymerase chain reactions. We determined the relationship between PAI-1/tPA mRNA expression and several clinical/laboratory parameters. Serum from 16 patients (nine patients with new-onset SLE and seven patients with stable SLE) was used in the study.

RESULTS

Plasminogen activator inhibitor-1 and tPA mRNA expression was significantly higher in GECs treated with serum of patients with new-onset SLE than other groups. The PAI-1 and tPA mRNA levels were also significantly correlated in GECs treated with serum from patients with SLE. Interestingly, both PAI-1 and tPA mRNA levels in GECs were inversely correlated with serum C4 level and positively correlated with SLE disease activity.

CONCLUSIONS

These results suggest that serum from patients with SLE may activate the fibrinolysis system in glomerulus, which may be involved in the pathogenesis of lupus nephritis.

High-Fat Diet-Induced Renal Proximal Tubular Inflammatory Injury: Emerging Risk Factor of Chronic Kidney Disease

Nowadays, with the improvements in living standards and changes in living habits, high-fat diet (HFD) has become much more common in the populations worldwide. Recent studies have shown that HFD could induce lipid accumulation, and structural and functional abnormalities, accompanied by the release of large amounts of pro-inflammatory cytokines, in proximal tubular epithelial cells (PTECs). These findings indicate that, as an emerging risk factor, PTEC injury-induced by HFD may be closely related to inflammation; however, the potential mechanisms underlying this phenomenon is still not well-known, but may involve the several inflammatory pathways, including oxidative stress-related signaling pathways, mitochondrial dysfunction, the myeloid differentiation factor 2/Toll like receptor 4 (MD2/TLR4) signaling pathway, the ERK1/2-kidney injury molecule 1 (KIM-1)-related pathway, and nuclear factor-κB (NF-κB) activation, etc., and the detailed molecular mechanisms underlying these pathways still need further investigated in the future. Based on lipid abnormalities-induced inflammation is closely related to the development and progression of chronic kidney disease (CKD), to summarize the potential mechanisms underlying HFD-induced renal proximal tubular inflammatory injury, may provide novel approaches for CKD treatment.

Dysregulation of tRNA-derived small RNAs and their potential roles in lupus nephritis

Objective

Lupus nephritis (LN) is a major end-organ complication of systemic lupus erythematosus (SLE), and the molecular mechanism of LN is not completely clear. Accumulating pieces of evidence indicate the potential vital role of tRNA-derived small RNAs (tsRNAs) in human diseases. Current study aimed to investigate the potential roles of tsRNAs in LN.

Methods

We herein employed high‐throughput sequencing to screen the expression profiles of tsRNAs in renal tissues of the LN and control groups. To validate the sequencing data, we performed quantitative real-time PCR (qRT-PCR) analysis. Correlational analysis of verified tsRNAs expression and clinical indicators was conducted using linear regression. The potential target genes were also predicted. The biological functions of tsRNAs were annotated by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis.

Results

Our findings revealed that the expression profiles of tsRNAs were significantly altered in the kidney tissues from LN patients compared with control. Overall, 160 tsRNAs were significantly dysregulated in the LN group, of which 79 were upregulated, whereas 81 were downregulated. Subsequent qRT-PCR results confirmed the different expression of candidate tsRNAs. Correlation analysis results found that expression of verified tsRNAs were correlated to clinical indicators. The target prediction results revealed that verified tsRNAs might act on 712 target genes. Further bioinformatics analysis uncovered tsRNAs might participate in the pathogenesis of LN through several associated pathways, including cell adhesion molecules, MAPK signaling pathway, PI3K-Akt signaling pathway and B cell receptor signaling pathway.

Conclusion

This study provides a novel insight for studying the mechanism of LN.

Cadherin Signaling in Cancer and Autoimmune Diseases

Cadherins mediate cell–cell adhesion through a dynamic process that is strongly dependent on the cellular context and signaling. Cadherin regulation reflects the interplay between fundamental cellular processes, including morphogenesis, proliferation, programmed cell death, surface organization of receptors, cytoskeletal organization, and cell trafficking. The variety of molecular mechanisms and cellular functions regulated by cadherins suggests that we have only scratched the surface in terms of clarifying the functions mediated by these versatile proteins. Altered cadherins expression is closely connected with tumorigenesis, epithelial–mesenchymal transition (EMT)-dependent fibrosis, and autoimmunity. We review the current understanding of how cadherins contribute to human health and disease, considering the mechanisms of cadherin involvement in diseases progression, as well as the clinical significance of cadherins as therapeutic targets.

Role of Endothelial Glucocorticoid Receptor in the Pathogenesis of Kidney Diseases

Glucocorticoids, as multifunctional hormones, are widely used in the treatment of various diseases including nephrological disorders. They are known to affect immunological cells, effectively treating many autoimmune and inflammatory processes. Furthermore, there is a growing body of evidence demonstrating the potent role of glucocorticoids in non-immune cells such as podocytes. Moreover, novel data show additional pathways and processes affected by glucocorticoids, such as the Wnt pathway or autophagy. The endothelium is currently considered as a key organ in the regulation of numerous kidney functions such as glomerular filtration, vascular tone and the regulation of inflammation and coagulation. In this review, we analyse the literature concerning the effects of endothelial glucocorticoid receptor signalling on kidney function in health and disease, with special focus on hypertension, diabetic kidney disease, glomerulopathies and chronic kidney disease. Recent studies demonstrate the potential role of endothelial GR in the prevention of fibrosis of kidney tissue and cell metabolism through Wnt pathways, which could have a protective effect against disease progression. Another important aspect covered in this review is blood pressure regulation though GR and eNOS. We also briefly cover potential therapies that might affect the endothelial glucocorticoid receptor and its possible clinical implications, with special interest in selective or local GR stimulation and potential mitigation of GC treatment side effects.

Lupus Vasculitis: An Overview

Lupus vasculitis (LV) is one of the secondary vasculitides occurring in the setting of systemic lupus erythematosus (SLE) in approximately 50% of patients. It is most commonly associated with small vessels, but medium-sized vessels can also be affected, whereas large vessel involvement is very rare. LV may involve different organ systems and present in a wide variety of clinical manifestations according to the size and site of the vessels involved. LV usually portends a poor prognosis, and a prompt diagnosis is fundamental for a good outcome. The spectrum of involvement ranges from a relatively mild disease affecting small vessels or a single organ to a multiorgan system disease with life-threatening manifestations, such as mesenteric vasculitis, pulmonary hemorrhage, or mononeuritis multiplex. Treatment depends upon the organs involved and the severity of the vasculitis process. In this review, we provide an overview of the different forms of LV, describing their clinical impact and focusing on the available treatment strategies.

Diagnostic value of TWEAK for predicting active lupus nephritis in patients with systemic lupus erythematosus: a systematic review and meta-analysis

Purpose

Accumulative studies showed that tumor necrosis factor (TNF)-like weak inducer of apoptosis (TWEAK) was up-regulated in the blood and urine from patients diagnosed with lupus nephritis (LN) and that it might be used as a novel biomarker for active LN. This meta-analysis aimed to determine the diagnostic value of TWEAK in active LN.

Methods

We searched the Cochrane Library, Embase, PubMed, Springer, Wanfang and CNKI databases for articles published up to 20 August 2020. The diagnostic capacity of TWEAK for active LN was assessed using pooled sensitivity and specificity, positive and negative likelihood ratios (PLR and NLR), diagnostic odds ratio (DOR), and area under the receiver operating characteristic curve (AUC). Quality assessment and publication bias were also evaluated. STATA 11.0 and Meta-Disc 1.4 were used to perform these analyses.

Results

Nine cross-sectional studies were included in this meta-analysis. The overall pooled sensitivity of TWEAK for the diagnosis of active LN was 0.69 (95% CI, 0.63–0.75), and specificity was 0.77 (95% CI, 0.71–0.82). The overall pooled PLR and NLR were 3.31 (95% CI, 2.05–5.35) and 0.38 (95% CI, 0.26–0.55), respectively, with a DOR of 10.89 (95% CI, 6.73–17.63) and AUC (SE) of 0.8276 (0.0289). Deeks’ funnel plot revealed that the publication bias was insignificant in the study (p = .32).

Conclusions

Our results suggest that TWEAK might be a potential biomarker for patients with active LN. Future cross-sectional and longitudinal studies are needed to confirm its diagnostic value, as well as to establish more definite cutoff for active LN.

IFN-I Mediates Lupus Nephritis From the Beginning to Renal Fibrosis

Lupus nephritis (LN) is a common complication of systemic lupus erythematosus (SLE) and a major risk factor for morbidity and mortality. The abundant cell-free nucleic (DNA/RNA) in SLE patients, especially dsDNA, is a key substance in the pathogenesis of SLE and LN. The deposition of DNA/RNA-immune complexes (DNA/RNA-ICs) in the glomerulus causes a series of inflammatory reactions that lead to resident renal cell disturbance and eventually renal fibrosis. Cell-free DNA/RNA is the most effective inducer of type I interferons (IFN-I). Resident renal cells (rather than infiltrating immune cells) are the main source of IFN-I in the kidney. IFN-I in turn damages resident renal cells. Not only are resident renal cells victims, but also participants in this immunity war. However, the mechanism for generation of IFN-I in resident renal cells and the pathological mechanism of IFN-I promoting renal fibrosis have not been fully elucidated. This paper reviews the latest epidemiology of LN and its development process, discusses the mechanism for generation of IFN-I in resident renal cells and the role of IFN-I in the pathogenesis of LN, and may open a new perspective for the treatment of LN.

[Thrombotic microangiopathy in rheumatology: a link between thrombosis and autoimmunity]

Uncontrolled hypercoagulation and inflammation (thromboinflammation), which are both independent and closely related and amplifying each other pathological processes, form the basis for pathogenesis of a wide range of diseases and complications, including immuno-inflammatory (autoimmune) rheumatic diseases, with the development of potentially fatal injuries of internal organs. Thrombotic microangiopathy is one of the most prominent prototypes of thromboinflammatory pathological conditions. The close link between environmental factors, hemostasis genetic defects and the complement system, inflammation and autoimmunity as pathogenetic mechanisms of microthrombosis draws particular attention to studying thrombotic microangiopathy in immuno-inflammatory rheumatic diseases, primarily systemic lupus erythematosus, antiphospholipid syndrome and scleroderma renal crisis. In future, these studies may be important for expanding the idea of the role of autoimmune mechanisms in pathogenesis of critical hemostasis disorders in human diseases, and for developing new approaches to therapy. Recently, special attention has been paid to the treatment of systemic lupus erythematosus and antiphospholipid syndrome with eculizumab, which is humanized monoclonal IgG2/4k antibody that blocks the complement component C5a and the membrane attack complex (C5b-9) formation, and which is registered for the treatment of atypical hemolytic uremic syndrome, paroxysmal nocturnal hemoglobinuria, as well as severe forms of myasthenia gravis and neuromyelitis optica. Further studies in this direction will create prerequisites for improving the prognosis not only in patients with orphan disorders, but also for widespread human diseases.