The pathology of lupus nephritis

Serum long non-coding Ribonucleic Acid H19 serves as a biomarker for systemic lupus erythematosus and participates in the disease progression

AIM

This study aimed to investigate the expression of H19 and its possible molecular mechanism in systemic lupus erythematosus (SLE).

METHODS

The expression of H19 and miR-19b in serum and peripheral blood mononuclear cells (PBMCs) were detected by reverse transcription quantitative polymerase chain reaction (RT-qPCR). Receiver operator characteristic (ROC) curve was constructed to evaluate the diagnostic value of serum H19 in SLE. Pearson correlation coefficient was used to analyze the correlation between serum levels of H19 and miR-19b. Flow cytometry and Cell counting kit-8 (CCK-8) assay were performed to detect cell apoptosis and viability. The levels of pro-inflammatory and anti-inflammatory factors were measured by enzyme-linked immunosorbent assay (ELISA). Luciferase reporter gene assay was conducted to verify the interaction between H19 and miR-19b.

RESULTS

The expression of H19 and miR-19b in SLE group were up-regulated and down-regulated, respectively. Serum H19 has certain clinical diagnostic value in SLE. In in vitro studies, overexpression of H19 can significantly inhibit the viability of PBMCs and promote apoptosis and inflammatory response of PBMCs by interacting with miR-19b.

CONCLUSIONS

The expression of H19 is upregulated in patients with SLE and plays a role in cell function and inflammation by targeting miR-19b in PBMCs, which may be one of the pathological mechanisms of SLE.

CD11b agonists offer a novel approach for treating lupus nephritis

Lupus nephritis (LN) develops in more than a third of all systemic lupus erythematosus (SLE) patients and is the strongest predictor of morbidity and mortality. Increased circulating levels of type I interferon (IFN I) and anti-double stranded DNA (anti-dsDNA) and anti-RNA binding protein (anti-RNP) antibodies lead to increased glomerular injury via leukocyte activation and glomerular infiltration. Uncontrolled Toll-like receptor (TLR) signaling in leukocytes results in increased production of IFN I and anti-dsDNA antibodies. ITGAM gene codes for integrin CD11b, the α-chain of integrin heterodimer CD11b/CD18, that is highly expressed in leukocytes and modulates TLR-dependent pro-inflammatory signaling. Three nonsynonymous SNPs in the ITGAM gene strongly correlate with increased risk for SLE and LN and with IFN I levels. Here we review the literature on the role of CD11b on leukocytes in LN. We also incorporate conclusions from several recent studies that show that these ITGAM SNPs result in a CD11b protein that is less able to suppress TLR-dependent pro-inflammatory pathways in leukocytes, that activation of CD11b via novel small molecule agonists suppresses TLR-dependent pathways, including reductions in circulating levels of IFN I and anti-dsDNA antibodies, and that CD11b activation reduces LN in model systems. Recent data strongly suggest that integrin CD11b is an exciting new therapeutic target in SLE and LN and that allosteric activation of CD11b is a novel therapeutic paradigm for effectively treating such autoimmune diseases.

Nanotechnology applications in rheumatology

Nanomedicine (NM) is the medical use of nanotechnology (NT). NT is the study and control of nanoscale structures (between approximately 1 and 100 nm). Nanomaterials are created by manipulating atoms and molecules at the nanoscale, resulting in novel physical and chemical properties. With its targeted tissue delivery capabilities, NT has enabled molecular modulation of the immune response and underlying inflammatory responses in individuals with rheumatic diseases (RD). NM has enabled targeted drug delivery, reduced adverse effects on non-target organs, raised drug concentration in synovial tissue, and slowed the progression of immune-mediated RD such as rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). Thus, NM has evolved in rheumatology prevention, diagnosis, and therapy. Animal models have proven superior outcomes to conventional techniques of treating specific illnesses. Nanodiamond (ND) immunomodulatory applications have been proposed as an alternative to traditional nanoparticles in the diagnosis and treatment of RA due to their small size and ability to be removed from the body without causing harm to the patient's organs, such as the liver. However, human clinical NM needs more research. We conducted a literature review to assess the present role of NM in clinical rheumatology, describing its current and future applications in the diagnosis and treatment of rheumatic diseases.

Immunoglobulin and complement-mediated glomerular diseases with an MPGN pattern of injury: Unmasking the diagnosis of lupus in a patient with hepatitis A infection

In cases with a broad differential or atypical features, it is important to continually review the original diagnosis. Diagnosing SLE can be challenging due to its multisystem presentations; a multidisciplinary approach is beneficial.

Association of ficolin-2 gene polymorphisms and susceptibility to systemic lupus erythematosus in Egyptian children and adolescents: a multicenter study

BACKGROUND

Pediatric-onset SLE (pSLE) is a multisystem autoimmune disease. Recently, the ficolin-2 (FCN2) gene has emerged as a potential candidate gene for susceptibility to SLE.

OBJECTIVES

The objective of this study was to evaluate the association of the FCN2 gene polymorphisms at positions -986 (G/A), -602 (G/A), -4 (A/G) and SNP C/T (rs3124954) located in intron 1, with susceptibility to pSLE in Egyptian children and adolescents.

METHODS

This was a multicenter study of 280 patients diagnosed with pSLE, and 280 well-matched healthy controls. The FCN2 promoter polymorphisms at -986 G/A (rs3124952), -602 G/A (rs3124953), -4 A/G (rs17514136) and SNP C/T (rs3124954) located in intron 1 were genotyped by polymerase chain reaction, while serum ficolin-2 levels were assessed using enzyme-linked immunosorbent assay.

RESULTS

The frequencies of the FCN2 GG genotype and G allele at -986 and -602 positions were significantly more represented in patients with pSLE than in controls (p < 0.001). Conversely, the FCN2 AA genotype and A allele at position -4 were more common in patients than in controls (p < 0.001). Moreover, patients carrying the FCN2 GG genotype in -986 position were more likely to develop lupus nephritis (odds ratio: 2.6 (95% confidence interval: 1.4-4.78); p = 0.006). The FCN2 AA genotype at position -4 was also identified as a possible risk factor for lupus nephritis (odds ratio: 3.12 (95% confidence interval: 1.25-7.84); p = 0.024).

CONCLUSION

The FCN2 promoter polymorphisms may contribute to susceptibility to pSLE in Egyptian children and adolescents. Moreover, the FCN2 GG genotype at position -986 and AA genotype at position -4 were associated with low serum ficolin-2 levels and may constitute risk factors for lupus nephritis in pSLE.

Knockdown of TRIM27 expression suppresses the dysfunction of mesangial cells in lupus nephritis by FoxO1 pathway

TRIM27 (tripartite motif-containing 27) is a member of the TRIM (tripartite motif) protein family and participates in a variety of biological processes. Some research has reported that TRIM27 was highly expressed in certain kinds of carcinoma cells and tissues and played an important role in the proliferation of carcinoma cells. However, whether TRIM27 takes part in the progression of lupus nephritis (LN) especially in cells proliferation remains unclear. Our study revealed that the overexpression of TRIM27 was observed in the kidneys of patients with LN, lupus mice and mesangial cells exposed to LN plasma which correlated with the proliferation of mesangial cells and ECM (extracellular matrix) deposition. Downregulation of TRIM27 expression suppressed the proliferation of mesangial cells and ECM accumulation in MRL/lpr mice and cultured human mesangial cells (HMCs) by regulating the FoxO1 pathway. Furthermore, the overexpression of FoxO1 remarkably decreased HMCs proliferation level and ECM accumulation in LN plasma-treated HMCs. In addition, the protein kinase B (Akt) signal pathway inhibitor LY294002 significantly reduced the expression of TRIM27 and inhibited the dysfunction of mesangial cells. These above data suggested that TRIM27 mediated abnormal mesangial cell proliferation in kidney of lupus and might be the potential target for treating mesangial cell proliferation of lupus nephritis.

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.

Parp1 protects against Aag-dependent alkylation-induced nephrotoxicity in a sex-dependent manner

Nephrotoxicity is a common toxic side-effect of chemotherapeutic alkylating agents. Although the base excision repair (BER) pathway is essential in repairing DNA alkylation damage, under certain conditions the initiation of BER produces toxic repair intermediates that damage healthy tissues. We have shown that the alkyladenine DNA glycosylase, Aag (a.k.a. Mpg), an enzyme that initiates BER, mediates alkylation-induced whole-animal lethality and cytotoxicity in the pancreas, spleen, retina, and cerebellum, but not in the kidney. Cytotoxicity in both wild-type and Aag-transgenic mice (AagTg) was abrogated in the absence of Poly(ADP-ribose) polymerase-1 (Parp1). Here we report that Parp1-deficient mice expressing increased Aag (AagTg/Parp1^−/−) develop sex-dependent kidney failure upon exposure to the alkylating agent, methyl methanesulfonate (MMS), and suffer increased whole-animal lethality compared to AagTg and wild-type mice. Macroscopic, histological, electron microscopic and immunohistochemical analyses revealed morphological kidney damage including dilated tubules, proteinaceous casts, vacuolation, collapse of the glomerular tuft, and deterioration of podocyte structure. Moreover, mice exhibited clinical signs of kidney disease indicating functional damage, including elevated blood nitrogen urea and creatinine, hypoproteinemia and proteinuria. Pharmacological Parp inhibition in AagTg mice also resulted in sensitivity to MMS-induced nephrotoxicity. These findings provide in vivo evidence that Parp1 modulates Aag-dependent MMS-induced nephrotoxicity in a sex-dependent manner and highlight the critical roles that Aag-initiated BER and Parp1 may play in determining the side-effects of chemotherapeutic alkylating agents.

Vitamin D receptor gene FokI polymorphism in Egyptian children and adolescents with SLE: A case-control study

Background Childhood-onset systemic lupus erythematosus (cSLE) is a lifelong autoimmune disorder. The vitamin D receptor (VDR) gene is a potential candidate gene for cSLE susceptibility. In this study, we aimed to investigate the FokI polymorphism in the VDR gene in Egyptian children and adolescents with SLE, to determine whether this polymorphism could be a genetic marker for cSLE susceptibility or disease activity and we also measured the serum level of 25-hydroxyvitamin D [25(OH) D] to assess its relation to such polymorphism. Methods This was a case-control study, which included 300 patients with cSLE and 300 age, sex, and ethnicity-matched healthy controls. All participants were genotyped for the VDR gene FokI (rs2228570) polymorphism by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), while the serum [25(OH) D] levels were measured by enzyme-linked immunosorbent assay (ELISA). Results The VDR FokI FF genotype and F allele were overrepresented among cSLE patients compared with the controls, [odds ratio (OR) = 2.7; 95% confidence interval (CI): 1.6-4.4 for the FF genotype; p = 0.000; and OR = 1.6; 95% CI: 1.27-2.05 for the F allele; p = 0.000, respectively]. We found a significant association between VDR FokI FF genotype with lupus nephritis (OR: 4.8; 95% CI: 2.2-10.6; p = 0.002); and high disease activity index score ( p = 0.01). Conclusions The FokI polymorphism in the VDR gene may contribute to susceptibility to SLE in Egyptian children and adolescents. Moreover, the FF genotype constituted a risk factor for the development of lupus nephritis and was associated with low serum [25(OH) D] levels as well as higher disease activity index score among studied patients with cSLE.

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.

Lupus nephritis in the Western Cape, a high prevalence area: an experience over three decades

Background

Systemic lupus erythematosus is a multisystem disease with serious complications, including lupus nephritis. Systemic lupus erythematosus is prevalent in the Western Cape, predominantly affecting women in the prime of their lives. Renal biopsy is an important tool for the management of the lupus patient with kidney disease, guiding treatment and assessing prognosis.

Aims

The aim of this study was to ascertain if there has been a change in the spectrum of renal pathology, patient characteristics and long-term outcomes in patients with lupus nephritis in our region over three decades.

Methods

We reviewed 315 records of systemic lupus erythematosus patients with suspected renal disease who underwent renal biopsy in the Renal Unit at Tygerberg Hospital over three decades between January 1983 and December 2012.

Results

Lupus nephritis consistently affected young women. Class IV lupus nephritis remained the most common pattern throughout the three decades. The overall five-year survival for this cohort was 67% (95% confidence interval (CI), 60–72%).

Conclusion

Class IV lupus nephritis remained the most frequent class in our cohort of patients with the poorest survival rates compared to other classes. The prognosis of lupus nephritis in our region is considerably worse than that reported elsewhere in the world.

Vitamin D receptor gene BsmI polymorphisms in Egyptian children and adolescents with systemic lupus erythematosus: A case-control study

Systemic lupus erythematosus (SLE) is a multisystemic autoimmune disease. The vitamin D receptor (VDR) gene is a candidate gene for susceptibility to autoimmune disorders. To date, only a few studies concerned the association of the VDR gene polymorphisms with childhood-onset SLE.In this study, we aimed to investigate the BsmI polymorphisms in the VDR gene, for the first time in Egyptian children and adolescents with SLE, to determine whether this polymorphism could be a marker of susceptibility to or severity of SLE and we also measured the serum level of 25-hydroxyvitamin D (25[OH] D) to assess its relation to such polymorphism.This was a case-control study including 100 patients with SLE and matched with age, sex, and ethnicity and 100 healthy controls. All subjects were genotyped for the VDR gene BsmI polymorphism by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), whereas the serum 25(OH) D levels were measured by enzyme-linked immunosorbent assay method.Compared to the contros subjects, the VDR BsmI BB genotype and B allele were overrepresented among SLE patients (odda ratio [OR]: 5.5; 95% confidence interval [CI]: 1.9-15.9; P = 0.002 and OR: 1.84; 95% CI: 1.21-2.80; P = 0.003; respectively). We found a significant association between VDR BsmI BB genotype with lupus nephritis (OR: 6.8; 95% CI: 1.18-50.5; P = 0.001). However, we did not observe any significant association of studied polymorphisms with other clinical manifestations, laboratory profiles of SLE, or disease activity score. Our data revealed no association between VDR BsmI genotypes or alleles and serum 25-hydroxyvitamin D levels among studied patients with SLE (all P > 0.05).We demonstrate for the first time, to the best of our knowledge, that the VDR BsmI gene polymorphisms may contribute to susceptibility to SLE in Egyptian children and adolescents. Moreover, we found that the BB genotype constituted a risk factor for the development of nephropathy among studied patients with SLE. However, we did not find any significant association of the VDR BsmI gene variants with other clinical manifestations, laboratory profiles of SLE, disease activity index score, or serum 25-hydroxyvitamin D levels.

Phosphoinositide 3-kinase/protein kinase B/periostin mediated platelet-derived growth factor-induced cell proliferation and extracellular matrix production in lupus nephritis

In the present study, the effect and mechanism of periostin on renal proliferation and extracellular matrix accumulation of lupus mice were investigated. MRL /lpr mice, known as lupus mice, were revealed to show enhanced periostin, proliferating cell nuclear antigen (PCNA), and extracellular matrix accumulation in the kidney accompanied by increased serum platelet-derived growth factor (PDGF). Again, cultured mouse mesangial cells (MMCs) were treated with PDGF, then periostin, and PCNA and secreted fibronectin were detected. The results showed that intracellular periostin and PCNA were respectively enhanced by 2.691 and 2.308 times in PDGF-treated MMC cells at 6 h after stimulation. In addition, secreted fibronectin was increased by 1.442 times. Next, the transfection of periostin shRNA vector in PDGF-stimulated MMC cells effectively suppressed periostin, PCNA and secreted fibronectin by 45.27%, 47.75%, and 39.95%, compared with PDGF-stimulated cells transfected with control vector. Furthermore, it was found that PDGF increased the expression of phospho-Akt (Ser 473) from 30 min to 6 h in MMCs. LY294002 effectively inhibited phospho-Akt (Ser 473) expression caused by PDGF stimulation. Then, periostin, PCNA, and fibronectin were respectively decreased by 69.61%, 46.00%, and 46.20%. In the end, phosphoinositide 3-kinase/protein kinase B/periostin was suggested to mediate PDGF-induced cell proliferation and extracellular matrix production in lupus nephritis.

Lupus nephritis: When and how often to biopsy and what does it mean?

Renal disease is a frequent complication of SLE which can lead to significant illness and even death. Today, a baseline renal biopsy is highly recommended for all subjects with evidence of lupus nephritis. Biopsy allows the clinician to recognize and classify different forms of autoimmune lupus glomerulonephritis, and to detect other glomerular diseases with variable pathogenesis which are not directly related to autoimmune reactivity, such as lupus podocytopathy. Moreover, not only glomerular diseases, but other severe forms of renal involvement, such as tubulo-interstitial nephritis or thrombotic microangiopathy may be detected by biopsy in lupus patients. Thus, an accurate definition of the nature and severity of renal involvement is mandatory to assess the possible risk of progression and to establish an appropriate treatment. The indications to repeat biopsy are more controversial. Some physicians recommend protocol biopsies to recognize the possible transformation from one class to another one, or to identify silent progression of renal disease, others feel that good clinical monitoring is sufficient to assess prognosis and to make therapeutic decisions. At any rate, although any decision should always be taken by considering the clinical conditions of the patient, there are no doubts that repeat renal biopsy may represent a useful tool in difficult cases to evaluate the response to therapy, to modulate the intensity of treatment, and to predict the long-term renal outcome both in quiescent lupus and in flares of activity.

What is damaging the kidney in lupus nephritis?

Despite marked improvements in the survival of patients with severe lupus nephritis over the past 50 years, the rate of complete clinical remission after immune suppression therapy is <50% and renal impairment still occurs in 40% of affected patients. An appreciation of the factors that lead to the development of chronic kidney disease following acute or subacute renal injury in patients with systemic lupus erythematosus is beginning to emerge. Processes that contribute to end-stage renal injury include continuing inflammation, activation of intrinsic renal cells, cell stress and hypoxia, metabolic abnormalities, aberrant tissue repair and tissue fibrosis. A deeper understanding of these processes is leading to the development of novel or adjunctive therapies that could protect the kidney from the secondary non-immune consequences of acute injury. Approaches based on a molecular-proteomic-lipidomic classification of disease should yield new information about the functional basis of disease heterogeneity so that the most effective and least toxic treatment regimens can be formulated for individual patients.

From the Large Scale Expression Analysis of Lupus Nephritis to Targeted Molecular Medicine

Lupus nephritis (LN) is one of the most severe complications of systemic lupus erythematosus (SLE). Current treatments for LN lack sufficient efficacy as they do not necessarily target the LN responsible pathways and therapeutic responses vary widely in the patient population. LN mouse models have been useful in delineating disease pathogenesis and for testing novel therapies, but they do not entirely represent the events happening in human LN. This review describes how recently developed systems biology technologies can help to integrate current knowledge with large scale experimental data to generate new hypotheses and insight into the regulatory events occurring in LN.

Analysis of renal mononuclear phagocytes in murine models of SLE

In this chapter we present methods for the isolation and characterization of mononuclear phagocytes from the kidneys of mice with SLE. Activation of these cells is associated with the onset of clinical disease in mice and infiltration with these cells is associated with poor prognosis in humans. Using magnetic beads followed by flow cytometric sorting, pure populations of cells are obtained that are functional in a variety of assays. Sufficient numbers of cells are obtained for genomic characterization. An analysis of the function of these cells should lead to a better understanding of the inflammatory processes that cause renal impairment in SLE and other renal inflammatory diseases.

Therapeutic effects of umbilical cord blood-derived mesenchymal stem cell transplantation in experimental lupus nephritis

Mesenchymal stem cells (MSCs) have been shown to possess immunomodulatory properties. Systemic lupus erythematosus is an autoimmune disease that results in nephritis and subsequent destruction of renal microstructure. We investigated whether transplantation of human umbilical cord blood-derived MSCs (uMSCs) is useful in alleviating lupus nephritis in a murine model. It was found that uMSCs transplantation significantly delayed the development of proteinuria, decreased anti-dsDNA, alleviated renal injury, and prolonged the life span. There was a trend of decreasing T-helper (Th) 1 cytokines (IFN-γ, IL-2) and proinflammatory cytokines (TNF-α, IL-6, IL-12) and increasing Th2 cytokines (IL-4, IL-10). The in vitro coculture experiments showed that uMSCs only inhibited lymphocytes and splenocytes proliferation but not mesangial cells. Long-term engraftment of uMSCs in the kidney was not observed either. Together, these findings indicated that uMSCs were effective in decreasing renal inflammation and alleviating experimental lupus nephritis by inhibiting lymphocytes, inducing polarization of Th2 cytokines, and inhibition of proinflammatory cytokines production rather than direct engraftment and differentiating into renal tissue. Therapeutic effects demonstrated in this preclinical study support further exploration of the possibility to use uMSCs from mismatched donors in lupus nephritis treatment.

Review article: systemic lupus erythematosus: a review for anesthesiologists

Systemic lupus erythematosus (SLE) is a chronic autoimmune connective tissue disorder, with a heterogeneous presentation. Disease severity is wide ranging, with most suffering milder forms; however, it is potentially fatal depending on organ involvement. The disorder was recognized as early as the Middle Ages, with the 12th-century physician Rogerius being the first to apply the term lupus to the classic malar rash, and in 1872, Moric Kaposi first recognized the systemic nature of the disease. Perioperatively, SLE can present major challenges to the anesthesiologist because of accrued organ damage, coagulation defects, and complex management regimes. In this article I highlight adult SLE manifestations and treatments pertinent to the anesthesiologist and discuss perioperative management of these complex patients.

Lupus nephritis: lessons from murine models

Lupus nephritis is a challenging clinical condition for which current therapies are unsatisfactory with respect to both remission induction and unwanted toxic effects. Despite intervention, the rates of end-stage renal disease seem to be increasing in the USA. Discoveries over the past decade have greatly improved our understanding of immune activation and effector inflammatory pathways in lupus nephritis; however, this increased understanding has not yet translated into the approval of an effective new therapeutic agent. An analysis of the mechanisms of action of novel immunomodulatory drugs in multiple models of murine lupus clearly shows that interacting networks of immune and effector pathways are recruited as the disease progresses. Reversing established disease by targeting a single cell population or inflammatory pathway is, therefore, difficult once long-lived autoreactive lymphocyte populations are present and peripheral organs are inflamed. Data from murine models of lupus suggest that we need to consider new paradigms for the management of systemic lupus erythematosus that include earlier immune intervention, long-term maintenance therapies and protection of target organs.

Clinical approach to lupus nephritis: recent advances

Kidney involvement is common in systemic lupus erythematosus (SLE). Its clinical presentations are highly variable, ranging from mild asymptomatic proteinuria and/or hematuria to rapidly progressive uremia. Histological evidence of lupus nephritis is present in most patients with SLE, even when they do not yet have clinical manifestations. Current classification ISN/RPS 2003 (International Society of Nephrology/Renal Pathology Society) of lupus nephritis was promoted by a widely perceived need to re-examine existing classification, provide clearer distinctions between the histological classes, and improve diagnostic reproducibility and interobserver agreement. Lupus nephritis is a serious disease whose prognosis can usually be improved dramatically by treatment, but treatment is potentially toxic, prolonged, and complex. Current treatment regimens combine corticosteroids with cyclophosphamide, azathioprine or ciclosporin; mycophenolate mofetil has received much recent attention as a potentially immune suppressive agent and less aggressive immunosuppressive regimens can be prescribed. SLE patients should be regular followed to detect early kidney involvement.

Hypovitaminosis D is associated with greater body mass index and disease activity in pediatric systemic lupus erythematosus

OBJECTIVES

To determine whether pediatric systemic lupus erythematosus (SLE) is associated with alterations in the vitamin D-parathyroid hormone (PTH) axis and to assess the relation between vitamin D deficiency and SLE activity.

STUDY DESIGN

25-hydroxy vitamin D [25(OH)D], 1,25-dihydroxy vitamin D [1,25(OH)2D], and intact PTH were measured in subjects with SLE (n = 38) and healthy controls (n = 207), ages 5 to 21 years. Vitamin D status and its relation with disease activity were assessed using multivariable logistic and linear regression.

RESULTS

Severe vitamin D deficiency (25(OH)D <10 ng/ml) was observed in a significantly higher proportion of subjects with SLE (36.8% vs 9.2%, P < .001). In SLE, the odds ratio (OR) for severe deficiency was 2.37 (P = .09), adjusting for age, sex, race, and season. However, for each 1 SD greater body mass index (BMI) z-score, 25(OH)D levels were 4.2 ng/mL lower (P = .01) in SLE, compared with controls. Adjusting for 25(OH)D levels, SLE was associated with significantly lower 1,25(OH)2D (P < .001) and intact PTH levels (P = .03). Greater SLE disease activity index scores were observed in those with 25(OH)D <20 ng/mL (P = .01).

CONCLUSIONS

SLE was associated with vitamin D deficiency, particularly among those subjects with SLE who were overweight. Future studies should assess the effect of vitamin D supplementation on skeletal and nonskeletal outcomes in SLE.

Up-regulated renal expression of TNF-α signalling adapter proteins in lupus glomerulonephritis

The role of tumour necrosis factor (TNF-α) signalling adapters in lupus nephritis (LN) is poorly understood. This study investigated renal expression of TNF-α and TNF signalling adapter proteins, including TNF receptor-associated death domain protein (TRADD), receptor-interacting protein (RIP) and TNF receptor-associated factor-2 (TRAF-2) in patients with LN. The renal expression of proliferating cell nuclear antigen (PCNA) and CD68 was also measured. The study showed that glomerular and tubular expression of TNF-α, TRADD, RIP and TRAF-2 was significantly up-regulated in class III and IV LN in which the intense staining was observed on the crescents, proximal and distal tubules and interstitial mononuclear cells. The number of PCNA-positive cells and CD68-positive cells (macrophages) was increased obviously in class III and IV LN. There was a correlation between the expression levels of TNF-α, TRADD, RIP, TRAF-2 and the number of PCNA-positive or CD68-positive cells and active index of renal pathology. These findings suggest that TNF-α and TNF-α adapters in patients with LN play a role in immunopathogenic injury via transmitting abnormal cell proliferating and proinflammatory signals. The findings have provided further insights into the role of TNF-α and its adapter proteins in the pathogenesis of LN and have important therapeutic implications.