Lupus Nephritis

MicroRNA miR-181d-5p regulates the MAPK signaling pathway by targeting mitogen-activated protein kinase 8 (MAPK8) to improve lupus nephritis

BACKGROUND

Lupus nephritis (LN) is a common immune disease. The microRNA (miR)-181d-5p is a potential target for treating kidney injury. However, the therapeutic role of miR-181d-5p in LN has not been investigated. This study aimed to investigate the role of miR-181d-5p in targeting mitogen-activated protein kinase 8 (MAPK8) and stimulating the MAPK signaling pathway in LN.

METHODS

RT-qPCR was performed to identify the variations in miR-181d-5p expression in peripheral blood mononuclear cells (PBMCs) obtained from 42 LN patients, 30 healthy individuals, 6 MRL/lpr mice and 6 C57BL/6 mice. Western blot was used to detect the effect of miR-181d-5p on the MAPK signaling pathway in THP-1 cells and MRL/lpr mice. Enzyme-linked immunosorbent assay (ELISA) was utilized to detect the effect of miR-181d-5p on antinuclear antibodies and inflammatory factors. A dual-luciferase reporter assay was used to verify whether miR-181d-5p directly targets MAPK8. Flow cytometry was performed to evaluate apoptosis rates in transfected THP-1 cells.

RESULTS

miR-181d-5p expression was downregulated in PBMCs of LN patients (P < 0.01) and MRL/lpr mice (P < 0.05). A dual luciferase reporter assay demonstrated that miR-181d-5p inhibits MAPK8 (P < 0.01). Overexpression of miR-181d-5p inhibited the phosphorylation of p38 (P < 0.001) and p44/42 (P < 0.01). Moreover, miR-181d-5p decreased the apoptosis rate of THP-1 cells (P < 0.001), and reduced the secretion of IL-6 (P < 0.01) and TNF-α (P < 0.01). Furthermore, overexpression of miR-181d-5p decreased anti-dsDNA antibody (P < 0.05), anti-Sm antibody (P < 0.01), and fibrosis levels in MRL/lpr mice.

CONCLUSION

Upregulation of miR-181d-5p showed anti-inflammatory and anti-apoptotic effects on THP-1 cells in vitro and kidney injury in vivo. These effects were achieved by miR-181d-5p targeting MAPK8 to inhibit phosphorylation of p38 and p44/42. These results may offer new insights for improving therapeutic strategies against lupus nephritis.

Remission and long-term remission of pediatric-onset systemic lupus erythematosus

Objectives

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease with diverse clinical presentations and prognoses. Remission can be achieved with or without glucocorticoid (GC) use, and several recent studies have suggested that long-term remission can be achieved in a small portion of patients. Nevertheless, few studies have investigated remission or long-term remission in the pediatric-onset SLE subgroup. This study analyzed the characteristics and factors associated with long-term remission and GC use in pediatric-onset SLE.

Methods

We enrolled 226 patients aged <18 years who received a diagnosis of SLE between January 2006 and December 2016. Three remission condition groups were defined: (A) complete remission, (B) clinical remission off GCs, and (C) clinical remission on GCs. Long-term remission was defined as remission for more than 5 years. We analyzed the treatment durations before remission, durations of remission, and risk factors for non-remission with persistent GC use.

Results

During follow-up, 8 patients (3.5%) achieved complete remission, 35 patients (15.5%) achieved clinical remission off GCs, and 93 patients (41.2%) achieved clinical remission on GCs. In groups A, B, and C, 12.5%, 68.6%, and 65.6% of patients, respectively, remained in remission for >1 year.

Conclusion

This study assessed remission of pediatric-onset SLE. Up to 60.2% of patients had clinical remission after treatment, and 19% of patients achieved remission off GCs. Long-term remission is rarer in pediatric-onset SLE than in adult-onset SLE.

Efficacy and safety of immunosuppressive agents for adults with lupus nephritis: a systematic review and network meta-analysis

Introduction

Various immunosuppressive regimens have been developed for the treatment of lupus nephritis (LN). This study aimed to compare the efficacy and safety of immunosuppressive regimens in adults with LN.

Methods

We systematically searched the PubMed, Embase, and Cochrane Central Register of Controlled Trials databases, including conference proceedings, trial registries, and reference lists, from inception until July 10, 2022. The effects of treatment were compared and ranked using the surface under the cumulative ranking curve (SUCRA). The primary endpoint was total remission. The secondary endpoints were complete remission, systemic lupus erythematosus disease activity index (SLEDAI), relapse, all-cause mortality, end-stage renal disease (ESRD), infection, herpes zoster, ovarian failure, myelosuppression, and cancer.

Results

Sixty-two trials reported in 172 studies involving 6,936 patients were included in the network meta-analysis. The combination of tacrolimus (TAC), mycophenolate mofetil (MMF), and glucocorticoid (GC) provided the best result for the total remission rate (SUCRA, 86.63%) and SLEDAI (SUCRA, 91.00%), while the combination of voclosporin (VCS) , MMF and GC gave the best improvement in the complete remission rate (SUCRA, 90.71%). The combination of cyclophosphamide (CYC), MMF and GC was associated with the lowest risk of relapse (SUCRA, 85.57%) and cancer (SUCRA, 85.14%), while the combination of obinutuzumab (OTB), MMF and GC was associated with the lowest risk of all-cause mortality (SUCRA, 84.07%). Rituximab (RTX) plus MMF plus GC was associated with the lowest risk of ESRD (SUCRA, 83.11%), while the risk of infection was lowest in patients treated with azathioprine (AZA) plus CYC plus GC (SUCRA, 68.59%). TAC plus GC was associated with the lowest risk of herpes zoster (SUCRA, 87.67%) and ovarian failure (SUCRA, 73.60%). Cyclosporine (CsA) plus GC was associated with the lowest risk of myelosuppression (SUCRA, 79.50%), while AZA plus GC was associated with the highest risk of myelosuppression (SUCRA, 16.25%).

Discussion

This study showed that a combination of TAC, MMF and GC was the best regimen for improving the total remission rate. The optimal regimen for specific outcomes should be highlighted for high-risk patients.

Glomerulonephritis

Glomerulonephritis (GN) encompasses several disorders that cause glomerular inflammation and injury through an interplay of immune-mediated mechanisms, host characteristics, and environmental triggers, such as infections. GN can manifest solely in the kidney or in the setting of a systemic illness, and presentation can range from chronic and relatively asymptomatic hematuria to fulminant renal failure. Classic acute GN is characterized by hematuria, edema, and hypertension, the latter 2 of which are the consequence of sodium and water retention in the setting of renal impairment. Although presenting signs and symptoms and a compatible clinical history can suggest GN, serologic and urinary testing can further refine the differential diagnosis, and renal biopsy can be used for definitive diagnosis. Treatment of GN can include supportive care, renin-angiotensin-aldosterone system blockade, immunomodulatory therapy, and renal transplant. Prognosis is largely dependent on the underlying cause of GN and can vary from a self-limited course to chronic kidney disease. This review focuses on lupus nephritis, IgA nephropathy, IgA vasculitis, and postinfectious GN.

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.

Lupus nephritis or not? A simple and clinically friendly machine learning pipeline to help diagnosis of lupus nephritis

OBJECTIVE

Diagnosis of lupus nephritis (LN) is a complex process, which usually requires renal biopsy. We aim to establish a machine learning pipeline to help diagnosis of LN.

METHODS

A cohort of 681 systemic lupus erythematosus (SLE) patients without LN and 786 SLE patients with LN was established, and a total of 95 clinical, laboratory data and 17 meteorological indicators were collected. After tenfold cross-validation, the patients were divided into training set and test set. The features selected by collective feature selection method of mutual information (MI) and multisurf were used to construct the models of logistic regression, decision tree, random forest, naive Bayes, support vector machine (SVM), light gradient boosting (LGB), extreme gradient boosting (XGB), and artificial neural network (ANN), the models were compared and verified in post-analysis.

RESULTS

Collective feature selection method screens out antistreptolysin (ASO), retinol binding protein (RBP), lupus anticoagulant 1 (LA1), LA2, proteinuria and other features, and the hyperparameter optimized XGB (ROC: AUC = 0.995; PRC: AUC = 1.000, APS = 1.000; balance accuracy: 0.990) has the best performance, followed by LGB (ROC: AUC = 0.992; PRC: AUC = 0.997, APS = 0.977; balance accuracy: 0.957). The worst performance is naive Bayes model (ROC: AUC = 0.799; PRC: AUC = 0.822, APS = 0.823; balance accuracy: 0.693). In the composite feature importance bar plots, ASO, RF, Up/Ucr, and other features play important roles in LN.

CONCLUSION

We developed and validated a new and simple machine learning pathway for diagnosis of LN, especially the XGB model based on ASO, LA1, LA2, proteinuria, and other features screened out by collective feature selection.

Polyamines from myeloid-derived suppressor cells promote Th17 polarization and disease progression

Myeloid-derived suppressor cells (MDSCs) are a group of immature myeloid cells that play an important role in diseases. MDSCs promote Th17 differentiation and aggravate systemic lupus erythematosus (SLE) progression by producing arginase-1 to metabolize arginine. However, the metabolic regulators remain unknown. Here, we report that MDSC derivative polyamines can promote Th17 differentiation via miR-542-5p in vitro. Th17 polarization was enhanced in response to polyamine treatment or upon miR-542-5p overexpression. The TGF-β/SMAD3 pathway was shown to be involved in miR-542-5p-facilitated Th17 differentiation. Furthermore, miR-542-5p expression positively correlated with the levels of polyamine synthetases in peripheral blood mononuclear cells of patients with SLE as well as disease severity. In humanized SLE model mice, MDSC depletion decreased the levels of Th17 cells, accompanied by reduced expression of miR-542-5p and these polyamine synthetases. In addition, miR-542-5p expression positively correlated with the Th17 level and disease severity in both patients and humanized SLE mice. Together, our data reveal a novel molecular pathway by which MDSC-derived polyamine metabolism enhances Th17 differentiation and aggravates SLE.

Evaluation of Proteinuria and Hematuria in Ambulatory Setting

Proteinuria and/or hematuria are common findings in ambulatory settings. Proteinuria can be glomerular and/or tubular in origin and it may be transient, orthostatic, or persistent. Persistent proteinuria may be indicative of a serious kidney pathology. Hematuria, which denotes the presence of an increased number of red blood cells in the urine, can be gross or microscopic. Hematuria can originate from the glomeruli or other sites of the urinary tract. Asymptomatic microscopic hematuria or mild proteinuria in an otherwise healthy child is less likely to be of clinical significance. However, the presence of both requires further workup and careful monitoring.

Chronic kidney disease in patients with childhood-onset systemic lupus erythematosus

BACKGROUND

Lupus nephritis (LN) is a frequent manifestation of childhood-onset systemic lupus erythematosus (cSLE) with a potential risk for kidney failure and poor outcomes. This study aimed to evaluate stages III, IV, and V of chronic kidney disease (CKD) and investigate risk factors for CKD in cSLE patients.

METHODS

We performed a nationwide observational cohort study in 27 pediatric rheumatology centers, including medical charts of 1528 cSLE patients. Data were collected at cSLE diagnosis, during follow-up, and at last visit or death, between September 2016 and May 2019.

RESULTS

Of 1077 patients with LN, 59 (5.4%) presented with CKD, 36/59 (61%) needed dialysis, and 7/59 (11.8%) were submitted for kidney transplantation. After Bonferroni's correction for multiple comparisons (p < 0.0013), determinants associated with CKD were higher age at last visit, urinary biomarker abnormalities, neuropsychiatric involvement, higher scores of disease activity at last visit and damage index, and more frequent use of methylprednisolone, cyclosporine, cyclophosphamide, and rituximab. In the regression model analysis, arterial hypertension (HR = 15.42, 95% CI = 6.12-38.83, p ≤ 0.001) and biopsy-proven proliferative nephritis (HR = 2.83, 95%CI = 1.70-4.72, p ≤ 0.001) increased the risk of CKD, while children using antimalarials had 71.0% lower CKD risk ((1.00-0.29) × 100%) than children not using them. The Kaplan-Meier comparison showed lower survival in cSLE patients with biopsy-proven proliferative nephritis (p = 0.02) and CKD (p ≤ 0.001).

CONCLUSIONS

A small number of patients manifested CKD; however, frequencies of dialysis and kidney transplantation were relevant. This study reveals that patients with cSLE with hypertension, proliferative nephritis, and absence of use of antimalarials exhibited higher hazard rates of progression to CKD. A higher resolution version of the Graphical abstract is available as Supplementary information.

Progress in traditional Chinese medicine and natural extracts for the treatment of lupus nephritis

Lupus nephritis (LN) is an autoimmune disease with multiple system involvement and is also one of the most serious forms of organ damage in systemic lupus erythematosus (SLE), which is mainly caused by the formation and deposition of immune complexes in glomeruli. More than 50% of SLE patients have clinical manifestations of renal damage. At present, the treatment of lupus nephritis is mainly based on glucocorticoids and immunosuppressants. However, due to adverse drug reactions and frequent recurrence or aggravation after drug reduction or withdrawal, the prognosis remains poor; thus, it is still one of the most important causes of end-stage renal failure. Therefore, new treatment strategies are urgently needed. This article aims to review the application of traditional Chinese medicine and natural extracts in the treatment of lupus nephritis to provide the basic mechanisms of treatment and a new treatment strategy with clear effects and high safety performance.

Serum amyloid A-to-albumin ratio as a potential biomarker to predict the activity, severity, and poor prognosis of systemic lupus erythematosus

Objectives

To evaluate the predictive value of serum amyloid A‐to‐albumin ratio (SAR) for active systemic lupus erythematosus (SLE), severe active SLE, and poor prognosis of SLE.

Methods

One hundred and eighty‐six patients with SLE undergoing treatment in our hospital were selected. The demographic characteristics, clinical data, and disease prognosis of all patients were collected and analyzed.

Results

There were significant differences in SLEDAI, total glyceride (TG), serum amyloid A (SAA), SAR, urinary microalbumin‐to‐creatinine ratio (ACR), erythrocyte sedimentation rate (ESR), albumin (ALB), complement 3 (C3), anti‐dsDNA, anti‐Sm positive rate, and anti‐dsDNA positive rate between active SLE and stable SLE patients. TG, SAR, C3, ACR, and positive anti‐dsDNA were independent influencing factors of active SLE, and the odds ratio (OR) values were 2.342, 10.921, 0.832, 1.451, and 2.476, respectively. The area under curves (AUCs) of SAA, ALB, and SAR for predicting active SLE and severe active SLE were 0.743, 0.724, 0.787, 0.711, 0.686, and 0.733, respectively. The AUC of SAR for predicting the poor prognosis of active SLE was 0.719. High SAR, high ACR, low C3, and positive anti‐dsDNA were high risk factors for poor prognosis. Kaplan–Meier (K‐M) survival analysis showed that patients with high SAR, high ACR, low C3, and positive anti‐dsDNA had shorter continuous remission time than that with low SAR, low ACR, high C3, and negative anti‐dsDNA.

Conclusion

SAR had high predictive value for active SLE, severe active SLE, and poor prognosis of SLE. High SAR may be a potential marker for predicting the activity and prognosis of Chinese patients with SLE.

Clinical relevance of glomerular IgM deposition in patients with lupus nephritis

BACKGROUND

The aim of the study was to investigate the clinical relevance of IgM deposition in patients with lupus nephritis (LN) in a large cohort.

RESULTS

217 patients with renal biopsy-proven active LN were enrolled. The associations between glomerular IgM deposition and clinicopathological parameters were further analyzed. IgM deposition was positively correlated with glomerular C1q and C3 deposition moderately (r = 0.436, P < 0.001; r = 0.408, P < 0.001, respectively), and inversely correlated with plasma levels of C3 and CFH mildly (r =  - 0.138, P = 0.043; r =  - 0.147, P = 0.037, respectively). By multivariate analysis, we found that glomerular IgM deposition independently contributed to glomerular C3 deposition in patients with LN (OR = 2.002, 95% CI 1.295-3.094, P = 0.002). In addition, we also found that patients with IgM 0-2+ had similar plasma CFH levels, but in patients with IgM3+-4+, plasma CFH levels were significantly lower (300.4 ± 155.8 μg/mL vs. 429.9 ± 187.5 μg/mL, P < 0.001). Furthermore, patients with high density of glomerular IgM and low levels of CFH had heavier proteinuria, higher serum creatinine and lower plasma C3 levels (5.7 ± 3.1 g/d vs. 4.7 ± 3.5 g/d, P = 0.037; 150.1 ± 121.0 μmol/L vs. 105.6 ± 97.1 μmol/L, P = 0.005; 0.3 ± 0.2 μg/L vs. 0.4 ± 0.2 μg/L, P = 0.04, respectively), comparing with those with low density of glomerular IgM and low levels of CFH.

CONCLUSIONS

Our results suggested the involvement of glomerular deposited IgM in complement activation and renal injury in LN.

Linc8986 and linc0597 in plasma are novel biomarkers for systemic lupus erythematosus

Despite increasing evidence that large intergenic non-coding RNAs (lincRNAs) are widely involved in human disease, the role of lincRNAs in the development of systemic lupus erythematosus (SLE) has remained largely elusive. The purpose of the present study was to investigate the expression of three lincRNAs (linc0597, linc8986 and linc7190) in the plasma of patients with SLE and their potential use as biomarkers for the diagnosis and treatment of SLE. Plasma samples were obtained from 54 patients with SLE, 24 patients with rheumatoid arthritis (RA), 24 patients with Sjogren's syndrome (SS) and 22 healthy controls. LincRNA expression levels were measured by reverse transcription-quantitative PCR. Compared with those in the healthy controls, the plasma levels of linc0597 and linc8986 were significantly increased in the patients with SLE (P<0.001), while the difference in the level of linc7190 was not significant (P=0.052). In addition, there was no significant difference in the levels of linc0597 and linc8986 among patients with RA, patients with SS and the healthy controls (P>0.05). Compared with patients with SLE without lupus nephritis (LN), the levels of linc0597 were significantly higher in patients with LN (P=0.044). For linc7190 and linc8986, there was no significant difference between patients with and without LN (P>0.05). Furthermore, complement component 3 (C3) levels were used to evaluate whether the expression of linc8986 and linc0597 is related to the activity of SLE. The results indicated that the levels of linc8986 and linc0597 were negatively correlated with the level of C3 (P<0.001 and P=0.004, respectively). Further analysis suggested that linc0597 and linc8986 were able to specifically identify patients with SLE and that a combination of linc0597 and linc8986 may improve the diagnostic accuracy. Therefore, the plasma levels of linc0597 and linc8986 may be suitable biomarkers for diagnosing SLE.

Principles of pediatric lupus nephritis in a prospective contemporary multi-center cohort

Lupus nephritis (LN) is a life-threatening manifestation of systemic lupus erythematosus (SLE) and is more common in children than adults. The epidemiology and management of childhood-onset SLE (cSLE) have changed over time, prompting the need to reassess expected outcomes. The purpose of this study is to use the Childhood Arthritis and Rheumatology Research Alliance (CARRA) prospective registry to validate historical principles of LN in a contemporary, real-world cohort. After an extensive literature review, six principles of LN in cSLE were identified. The CARRA registry was queried to evaluate these principles in determining the rate of LN in cSLE, median time from cSLE diagnosis to LN, short-term renal outcomes, and frequency of rituximab as an induction therapy. Of the 677 cSLE patients in the CARRA registry, 32% had documented LN. Decline in kidney function was more common in Black cSLE patients than non-Black patients (p = 0.04). Black race was associated with worse short-term renal outcomes. In short-term follow up, most children with LN had unchanged or improved kidney function, and end stage kidney disease (ESKD) was rare. Ongoing follow-up of cSLE patients in the CARRA registry will be necessary to evaluate long-term outcomes to inform risk, management, and prognosis of LN in cSLE.

Electron microscopy study of 496 cases of lupus nephritis: A single-center experience

INTRODUCTION

Renal involvement is seen in about 40-82% of systemic lupus erythematosus (SLE) Asian patients. The exact diagnosis and classification of lupus nephritis are important for treatment and prognosis. This study aimed to investigate the value of electron microscopy (EM) in the diagnosis and classification of lupus nephritis compared with light microscopy.

METHOD

In this cross-sectional referral-center 16-year study of lupus nephritis, the final diagnosis was based on the EM study. Primary light microscopy findings were compared with EM diagnosis. Moreover, Immunofluorescence patterns distribution was assessed.

RESULTS

From 496 patients diagnosed with lupus nephritis based on EM, 225(45.4%) of patients were categorized in class IV, followed by 98(19.7%), 93(18.8%), 46(9.3%), and 14(2.8%) who were categorized into classes of II, III, V, and VI respectively. Only 1(0.2%) patient belonged to class I, and 19(3.8%) cases were diagnosed with mixed two classes. Using EM was essential for diagnosing 25.6% of cases taking the correct classification by light microscopy into account; however, disregarding correct classification, this could change to a 7.4% contribution rate of EM. The most common cause of misdiagnosis, disregarding incorrect classification, was inadequate or wrong tissue. Positive associations were detected between tubular atrophy and interstitial fibrosis of both electron and light microscopy with different classes (P < 0.001).

CONCLUSION

While light microscopy is highly accurate for diagnosing lupus nephritis regardless of correct classification, EM contributes substantially to the correct classification of lupus nephritis types.

TNIP1/ABIN1 and lupus nephritis: review

SLE is a complex autoimmune disease with genetic, epigenetic, immune-regulatory, environmental and hormonal factors. Kidney inflammation and injury, termed lupus nephritis (LN), occurs in over half of patients with SLE and is a leading cause of disability and death. There is a high degree of short-term and long-term side effects associated with current LN therapies and they are not effective for many patients. Thus, novel therapies with reduced toxicity and improved efficacy are drastically needed. Many of the known LN susceptibility genes have functions that mediate inflammation via cytokine/chemokine production and activation of myeloid and B cells. Understanding the cellular and molecular mechanisms mediated by these variant gene products provides valuable insight for the development of improved and personalised diagnostics and therapeutics. This review describes variants in the TNIP1 (tumour necrosis factor α-induced protein 3-interacting protein 1) gene associated with risks for SLE and LN and potential roles for loss of function of its protein product ABIN1 in the activation of myeloid and B-cell-mediated injury in LN.

Risk factors of infection-associated mortality in children with lupus nephritis in under-resourced areas

INTRODUCTION

Treatment of lupus nephritis class III, IV and V with immunosuppressive therapy increases patient survival but poses a risk of infection-related mortality. This study was conducted to evaluate risk factors for fatal infection in children with lupus nephritis in under-resourced areas.

METHODS

Medical records of patients, who were admitted to a tertiary-care university-based hospital from January 2002 to July 2018 with the diagnosis of systemic lupus erythematosus, were reviewed. Only patients aged less than 18 years with lupus nephritis and documented infection were included in the study. The primary outcome was infection-associated mortality. The logistic regression model was used to identify independent variables associated with fatal infection. Predicted probabilities of infection-related mortality adjusted for factors significant in multivariate analysis were calculated using marginal effects at representative values.

RESULTS

Infection-related deaths occurred in 27 of 179 patients (15.1%). Hospital-acquired infections occurred in 72 of 375 episodes of hospital admissions (19.2%) and 13 hospital-acquired infections (18.1%) resulted in fatal infection. Invasive fungal infections were the leading cause of death (44.4%) and pulmonary infections were the predominant site (55.5%). Haemoglobin levels and glomerular filtration rates were significantly lower in deceased versus surviving patients. Percentages of patients with hospital-acquired infections, invasive fungal infections and pulmonary infections were significantly higher in deceased than surviving patients. Urine protein, the neutrophil-to-lymphocyte ratio, cumulative methylprednisolone dose and daily prednisolone dose were significantly higher in deceased than surviving patients. In multivariate analysis, a neutrophil-to-lymphocyte ratio more than 20, invasive fungal infections and high daily prednisolone dose were independently predictive of fatal infection with adjusted odds ratio of 3.02 (95% confidence interval 1.02-8.97, p = 0.04), 15.08 (95% confidence interval 4.72-48.24, p < 0.001) and 1.03 (95% confidence interval 1.01-1.06, p = 0.04), respectively. A high daily prednisolone dose intensified the impact of invasive fungal infections and high neutrophil-to-lymphocyte ratio on predicted probability of infection-associated mortality.

CONCLUSIONS

Prevention of invasive fungal infections and minimization of daily prednisolone should be emphasized in routine clinical practice of children with lupus nephritis in under-resourced areas to achieve better survival. Children with lupus nephritis and a high neutrophil-to-lymphocyte ratio should be under cautious surveillance for infection.