Geographical distribution, a risk factor for the incidence of lupus nephritis in China

Hospital Healthcare Resource Utilization and Associated Hospital Costs of Patients With Lupus Nephritis in China: A National Administrative Claim Database Study

OBJECTIVES

Assess hospital healthcare resource utilization (HCRU) and associated hospital costs of patients with lupus nephritis (LN) in China and compare these outcomes with a systemic lupus erythematosus (SLE) cohort (SLE with/without LN) as well as exploring the effect of end-stage kidney disease (ESKD).

METHODS

This retrospective administrative claims-based analysis identified patients with SLE and SLE with LN from China using diagnosis codes and keywords. Patients with LN were subcategorized by presence of ESKD. Outcomes included all-cause and disease-specific HCRU (defined as healthcare visits including inpatient and outpatient visits) and medical costs (in 2022 US dollars).

RESULTS

In total, 3645 patients with SLE were included, of whom 404 (11%) had LN. Among those with LN, 142 (35%) had ESKD. Median (interquartile range) all-cause healthcare visits per patient per month (PPPM) was significantly greater for patients with LN (2.08 [4.01]) vs SLE (0.92 [1.64]; P < .0001). Patients with LN and ESKD (3.00 [4.18]) had numerically more all-cause healthcare visits PPPM compared with LN patients without ESKD (1.50 [3.45]). Median all-cause costs PPPM were significantly greater among patients with LN ($287.46 [477.15]) vs SLE ($113.09 [267.39]; P < .0001) and numerically higher for patients with LN and ESKD ($466.29 [958.90]) vs LN without ESKD ($223.50 [319.56]).

CONCLUSIONS

Chinese patients with LN had greater HCRU and hospital healthcare costs compared with the general SLE cohort. This burden was higher for those with ESKD. These data highlight the substantial HCRU among patients with LN in China, especially those with ESKD, suggesting the need for early diagnosis and timely management of LN to mitigate the economic burden.

Lupus Nephritis from Pathogenesis to New Therapies: An Update

Lupus Nephritis (LN) still represents one of the most severe complications of Systemic Lupus Erythematosus (SLE) and a major risk factor for morbidity and mortality. However, over the last few years, several studies have paved the way for a deeper understanding of its pathogenetic mechanisms and more targeted treatments. This review aims to provide a comprehensive update on progress on several key aspects in this setting: pathogenetic mechanisms of LN, including new insight into the role of autoantibodies, complement, vitamin D deficiency, and interaction between infiltrating immune cells and kidney resident ones; the evolving role of renal biopsy and biomarkers, which may integrate information from renal histology; newly approved drugs such as voclosporin (VOC) and belimumab (BEL), allowing a more articulate strategy for induction therapy, and other promising phase III-immunosuppressive (IS) agents in the pipeline. Several adjunctive treatments aimed at reducing cardiovascular risk and progression of chronic renal damage, such as antiproteinuric agents, represent an important complement to IS therapy. Furthermore, non-pharmacological measures concerning general lifestyle and diet should also be adopted when managing LN. Integrating these therapeutic areas requires an effort towards a holistic and multidisciplinary approach. At the same time, the availability of an increasingly wider armamentarium may translate into improvements in patient's renal outcomes over the next decades.

Systemic lupus erythematosus is associated with lower risk of hepatitis B virus infection: A multivariable Mendelian randomization study in East Asian population

The relationship between systemic lupus erythematosus (SLE) and hepatitis B virus (HBV) infection is still unclear. We conducted a two-sample Mendelian randomization (MR) analysis using summary statistics from genome-wide association studies for SLE and HBV infection in individuals of East Asian ancestry. The inverse-variance weighted (IVW) method, weighted median (WM) method, and MR-Egger method were used to estimate the causal effect of SLE on HBV infection. Additionally, we performed a multivariable MR analysis adjusting for the effects of body mass index and rheumatoid arthritis. This MR study included a total of 225 106 individuals of East Asian ancestry, comprising 5616 cases and 219 490 controls. The IVW method (OR: 0.79, p = 3.34E-08) and the WM method (OR: 0.79, p = 9.09E-06) revealed a causal relationship between genetically predicted SLE and a low risk of HBV infection. The multivariable MR analysis still suggested a low risk of HBV infection associated with SLE (OR: 0.83, p = 2.89E-06). Our MR analysis supports a causal relationship between SLE and a low risk of HBV infection in individuals of East Asian ancestry.

hUC-MSC transplantation therapy effects on lupus-prone MRL/lpr mice at early disease stages

BACKGROUND

The efficacy of human umbilical cord mesenchymal stem cell (hUC-MSC) transplantation in treating systemic lupus erythematosus (SLE) has been confirmed by small-scale clinical trials. However, these trials focused on severe or refractory SLE, while few studies focused on mild SLE. Therefore, this study focused on the therapeutic effects of hUC-MSC transplantation in early-stage or mild MRL/lpr lupus model mice.

METHODS

Commercially available hUC-MSCs were transplanted into 8-week-old MRL/lpr mice by tail vein injection. Flow cytometry was used to analyze B cells and their subsets in the peripheral blood. Further, plasma inflammatory factors, autoantibodies, and plasma biochemical indices were detected using protein chip technology and ELISA kits. In addition, pathological staining and immunofluorescence were performed to detect kidney injury in mice.

RESULTS

hUC-MSC transplantation did not affect the mice's body weight, and both middle and high dose hUC-MSC transplantation (MD and HD group) actually reduced spleen weight. hUC-MSC transplantation significantly decreased the proportion of plasmablasts (PB), IgG1- PB, IgG1+ PB, IgG1+ memory B (MB) cells, IgG1+ DN MB, and IgG1+ SP MB cells. The hUC-MSC transplantation had significantly reduced plasma levels of inflammatory factors, such as TNF-α, IFN-γ, IL-6, and IL-13. Pathological staining showed that the infiltration of glomerular inflammatory cells was significantly reduced and that the level of glomerular fibrosis was significantly alleviated in hUC-MSC-transplanted mice. Immunofluorescence assays showed that the deposition of IgG and IgM antibodies in the kidneys of hUC-MSC-transplanted mice was significantly lower than in the control.

CONCLUSION

hUC-MSC transplantation could inhibit the proliferation and differentiation of peripheral blood B cells in the early-stage of MRL/lpr mice, thereby alleviating the plasma inflammatory environment in mice, leading to kidney injury remission. The study provides a new and feasible strategy for SLE treatment.

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.

Sysmex UN2000 detection of protein/creatinine ratio and of renal tubular epithelial cells can be used for screening lupus nephritis

OBJECTIVES

This study is aimed to evaluate if automated urine sediment analysis UN2000 can be used to screen lupus nephritis.

METHODS

UN2000 was used to examine 160 urine samples from patients with systemic lupus erythematosus and 124 urine samples from Lupus nephritis. The result of protein/creatinine ratio(P/C) and renal tubular epithelial cells (RTEC) were evaluated. With biochemical analysis and microscopic examination as the gold standard, the Kappa consistency test was used to analyze the accuracy of P/C and RTEC. Analysis was to evaluate the accuracy of P/C single item or RTEC single item and both screening lupusnephritis.

RESULTS

The consistency of P/C and the gold standard, and that of RTEC and the gold standard are respectively strong and good (0.858 vs. 0.673). The specificity, positive predictive value, and coincidence were the highest when P/C ≥ 2 + was set as the only screening standard for lupus nephritis. When the standard was selected between P/C ≥ 2 + or RTEC > 2.8 cells/µl, the sensitivity and negative predictive value were the highest.

CONCLUSION

UN 2000 can be used to screen lupus nephritis by detecting P/C and RTEC.

Risk factors for 1-year hospital readmissions in patients with systemic lupus erythematosus

To reveal the characteristics of and risk factors for systemic lupus erythematosus (SLE) patients with frequent readmission aiming at intervening early and improve the quality of care during initial hospitalizations. This was a single-center, retrospective case-control study involving 521 hospitalized patients with SLE from January 2014 to December 2016 in the Affiliated Hospital of Guangdong Medical University. A total of 521 patients were enrolled, including 400 patients who were hospitalized once and 121 patients who were hospitalized repeatedly, and 23.2% of the patients were readmitted within 1 year. The results showed that the age of SLE onset (odds ratio [OR] 1.022, 95% confidence interval [CI] 1.007-1.036), serum albumin (OR 0.965, 95% CI 0.942-0.989), and cystatin C (OR 1.404, 95% CI 1.180-1.670) were closely related to readmission. The most common causes of readmission were infections (52 cases, 28.4%), especially respiratory tract infections, and lupus activity or recurrence (45 cases, 24.6%). Special attention should be paid to SLE patients with older age of onset, low serum albumin levels, and high cystatin C levels to avoid infection and recurrence with the aim of reducing the hospital readmission rate.

Detection of renal hypoxia configuration in patients with lupus nephritis: a primary study using blood oxygen level-dependent MR imaging

BACKGROUND

Renal microstructure and function are closely associated with oxygenation homeostasis. Analyzing renal blood oxygen level‒dependent (BOLD) magnetic resonance imaging (MRI) examination results will provide information on the biological status of the kidneys. The current study was performed to explore the hypoxia mode of the entire renal parenchyma in patients with lupus nephritis (LN).

METHODS

A total of 23 adult patients with LN and 18 healthy volunteers were recruited. R²* values were acquired using BOLD MRI analysis. The narrow rectangular region of interest was used to explore the hypoxia configuration in entire depths of renal parenchyma. Acquired sequential R²* data were fitted using four categories of mathematic functions. The tendency of R²* data in both patients with LN and healthy volunteers was also compared using repeated-measures analysis of variance.

RESULTS

R²* data from the superficial cortex to deep medulla displayed two patterns called a sharp uptrend style and a flat uptrend style. After sequential R²* data were fitted individually with the use of four mathematic formulas, the multiple-compartment Gaussian function showed the highest goodness of fit. Compared with two categories of R²* value styles, the R²* tendency of entire parenchyma in patients with LN was different from that in healthy volunteers.

CONCLUSIONS

Deep renal medullary oxygenation was not always overtly lower than oxygenation in the superficial renal cortical zone. The manifestation of renal parenchyma oxygenation could be described using a Gaussian function model. Deoxygenation tolerance was damaged in patients with LN.

Mycophenolate mofetil in the treatment of Chinese patients with lupus nephritis: A PRISMA-compliant meta-analysis

BACKGROUD

Mycophenolate mofetil (MMF) has been recommended for the treatment of lupus nephritis (LN). Although inter-racial differences exist regarding the appropriate dose and efficacy of MMF in patients with LN, no definitive meta-analysis has yet been conducted in Chinese patients. This analysis investigated the efficacy and safety of MMF in Chinese patients with proliferative LN.

METHODS

A systematic literature search was conducted to select randomized controlled trials that reported at least one of the following: complete remission (CR), partial remission, total remission (TR; defined as complete remission + partial remission), relapse rate, serum creatinine, creatinine clearance, end-stage renal disease, death, infections, amenorrhea, leukopenia, alopecia, gastrointestinal symptoms, or liver damage.

RESULTS

Eighteen trials (927 patients) were included; 14 (750 patients) reported CR, partial remission, and TR. Two trials (58 patients) reported relapse rates during maintenance treatment. MMF induction significantly improved CR and TR vs cyclophosphamide (relative risk 1.34, 95% confidence interval: 1.13-1.58; P < .001; relative risk 1.16, 95% confidence interval: 1.02-1.33; P = .03), and was associated with significantly lower risks of infection (P < .001), amenorrhea (P < .001), leukopenia, and alopecia. No significant difference in relapse rate was evident between the MMF and azathioprine groups (P = .66).

CONCLUSION

According to this meta-analysis of 18 trials, MMF is significantly more effective than cyclophosphamide induction, and is associated with reduced incidences of infections, amenorrhea, leukopenia, and alopecia in Chinese patients with proliferative LN.

Detection of water-molecular-motion configuration in patients with lupus nephritis: a primary study using diffusion-weighted imaging

BACKGROUND

Lupus nephritis (LN) is one of most common types of secondary glomerulonephritis, which is characterized by longitudinal pathological changes. Microstructural lesions of LN will impact the motion of water molecules, which can be detected by diffusion-weighted imaging (DWI). There are few reported measurements of water diffusion in patients with LN, and the nature of water diffusion across the entire depth of the renal parenchyma remains largely unknown.

METHODS

Twenty adult patients with LN and 11 healthy volunteers underwent DWI inspection. Renal biopsy samples were characterized based on the revised ISN/RPS 2003 classification. The apparent-diffusion coefficient (ADC) was calculated via fitting into a mono-exponential model. To compare the ADC level across the entire renal parenchyma between the two groups, repeated-measures analysis of variance (RM-ANOVA) was performed. ADC data derived from DWI pictures were transformed into tridimensional maps by MATLAB software.

RESULTS

Compared with data from healthy volunteers, lower average ADC values with major undulatory magnitudes were found in patients with LN, especially in the cortical zone. Tridimensional maps of patients with LN displayed geographic terrain-like canyons and/or valleys that were different from the corresponding terrain-like flatlands and/or plateaus in healthy volunteers. A heterogeneity of ADC values was found in bilateral kidneys. Left kidneys predominated higher ADC values in patients with LN. The ADC values across the entire renal parenchyma exhibited statistically significant differences among the three identified pathological subclasses (P < 0.001).

CONCLUSIONS

Analysis of the motion of water molecules across the entire renal parenchyma may be helpful for better understanding the pathological conditions of LN, for which microstructural and functional heterogeneity may be detected and visualized via DWI.

Mechanistic insights into environmental and genetic risk factors for systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease involving multiple organ systems with diverse presentation, primarily affecting women of reproductive age. Various genetic and environmental risk factors are involved in the pathogenesis of SLE, and many SLE susceptibility genes have been identified recently; however, gene therapy is not a viable clinical option at this time. Thus, environmental risks factors, particularly regional characteristics that can be controlled, need to be further investigated. Here, we systematically explored these risk factors, including ultraviolet radiation, seasonal distribution, geographical distribution, and climate factors, and also summarized the mechanisms related to these risk factors. Probable mechanisms were explicated in at least four aspects including inflammatory mediators, apoptosis and autophagy in keratinocytes, epigenetic factors, and gene-environment interactions. This information is expected to provide practical insights into these risk factors in order to benefit patients with SLE and facilitate the development of potential therapeutic strategies.

Profiling analysis of circulating microRNA in peripheral blood of patients with class IV lupus nephritis

Renal involvement in Systemic Lupus Erythematous (SLE) patients is one of the leading causes of morbidity and a significant contributor to mortality. It’s estimated that nearly 50% of SLE individuals develop kidney disease in the first year of the diagnosis. Class IV lupus nephritis (LN-IV) is the class of lupus nephritis most common in Colombian patients with SLE. Altered miRNAs expression levels have been reported in human autoimmune diseases including lupus. Variations in the expression pattern of peripheral blood circulating miRNAs specific for this class of lupus nephritis could be correlated with the pathophysiological status of this group of individuals. The aim of this study was to evaluate the relative abundance of circulating microRNAs in peripheral blood from Colombian patients with LN-IV. Circulating miRNAs in plasma of patients with diagnosis of LN-IV were compared with individuals without renal involvement (LNN group) and healthy individuals (CTL group). Total RNA was extracted from 10 ml of venous blood and subsequently sequenced using Illumina. The sequences were processed and these were analyzed using miRBase and Ensembl databases. Differential gene expression analysis was carried out with edgeR and functional analysis were done with DIANA-miRPath. Analysis was carried out using as variables of selection fold change (≥2 o ≤-2) and false discovery rate (0.05). We identified 24 circulating microRNAs with differential abundance between LN-IV and CTL groups, fourteen of these microRNAs are described for the first time to lupus nephritis (hsa-miR-589-3p, hsa-miR-1260b, hsa-miR-4511, hsa-miR-485-5p, hsa-miR-584-5p, hsa-miR-543, hsa-miR-153-3p, hsa-miR-6087, hsa-miR-3942-5p, hsa-miR-7977, hsa-miR-323b-3p, hsa-miR-4732-3p and hsa-miR-6741-3p). These changes in the abundance of miRNAs could be interpreted as alterations in the miRNAs-mRNA regulatory network in the pathogenesis of LN, preceding the clinical onset of the disease. The findings thus contribute to understanding the disease process and are likely to pave the way towards identifying disease biomarkers for early diagnosis of LN.

The effect of ethnicity and genetic ancestry on the epidemiology, clinical features and outcome of systemic lupus erythematosus

In this in-depth review, we examine the worldwide epidemiology of SLE and summarize current knowledge on the influence of race/ethnicity on clinical manifestations, disease activity, damage accumulation and outcome in SLE. Susceptibility to SLE has a strong genetic component, and trans-ancestral genetic studies have revealed a substantial commonality of shared genetic risk variants across different genetic ancestries that predispose to the development of SLE. The highest increased risk of developing SLE is observed in black individuals (incidence 5- to 9-fold increased, prevalence 2- to 3-fold increased), with an increased risk also observed in South Asians, East Asians and other non-white groups, compared with white individuals. Black, East Asian, South Asian and Hispanic individuals with SLE tend to develop more severe disease with a greater number of manifestations and accumulate damage from lupus more rapidly. Increased genetic risk burden in these populations, associated with increased autoantibody reactivity in non-white individuals with SLE, may explain the more severe lupus phenotype. Even after taking into account socio-economic factors, race/ethnicity remains a key determinant of poor outcome, such as end-stage renal failure and mortality, in SLE. Community measures to expedite diagnosis through increased awareness in at-risk racial/ethnic populations and ethnically personalized treatment algorithms may help in future to improve long-term outcomes in SLE.

Chinese SLE Treatment and Research Group (CSTAR) registry:VIII. Influence of socioeconomic and geographical variables on disease phenotype and activity in Chinese patients with SLE

AIM

The aim of this study was to estimate the influence of socioeconomic and geographical variables on disease phenotype and activity of systemic lupus erythematosus (SLE) in a Chinese population.

METHODS

Data on 904 therapy-naïve SLE patients from the Chinese SLE Treatment and Research Group (CSTAR), which is a nation-wide database of SLE patients, were used to evaluate the influence of socioeconomic status (SES) and geographical regions on disease phenotypes. The influence of regional climate and economic variables (i.e., data from the database of the Chinese Statistical Yearly Annals) on disease activity and nephropathy was further analyzed in a multivariate analysis to identify some of the environmental factors contributing to SLE.

RESULTS

Phenotype differences in SLE were found between patients with different SES. In the multivariate regression analysis that considered regional economic and climate factors, after adjusting for age, gender and disease duration, lower educational levels (β: -0.122, P = 0.001), lower availability of medical technical personnel (MTP) per 1000 people (β: -0.192, P < 0.001), higher annual duration of sunshine (β: 0.178, P = 0.010) and residence in southern China (β: 0.165, P = 0.001) were significantly associated with higher disease activity scores. Living in southern China (odds ratio [OR]: 1.907, P = 0.002) seemed to be a significant risk factor for nephropathy. A high number of MTP per 1000 people (OR: 0.951, P = 0.014) and relatively high temperatures were determined to be protective factors for nephropathy (OR: 0.946, P = 0.011).

CONCLUSIONS

The phenotype pattern and disease activity varied between SLE patients by SES and other regional variables, such as educational level, availability of medical technical personnel, annual sunshine duration and regional temperature.

The role of geographical ecological studies in identifying diseases linked to UVB exposure and/or vitamin D

Using a variety of approaches, researchers have studied the health effects of solar ultraviolet (UV) radiation exposure and vitamin D. This review compares the contributions from geographical ecological studies with those of observational studies and clinical trials. Health outcomes discussed were based on the author's knowledge and include anaphylaxis/food allergy, atopic dermatitis and eczema, attention deficit hyperactivity disorder, autism, back pain, cancer, dental caries, diabetes mellitus type 1, hypertension, inflammatory bowel disease, lupus, mononucleosis, multiple sclerosis, Parkinson disease, pneumonia, rheumatoid arthritis, and sepsis. Important interactions have taken place between study types; sometimes ecological studies were the first to report an inverse correlation between solar UVB doses and health outcomes such as for cancer, leading to both observational studies and clinical trials. In other cases, ecological studies added to the knowledge base. Many ecological studies include other important risk-modifying factors, thereby minimizing the chance of reporting the wrong link. Laboratory studies of mechanisms generally support the role of vitamin D in the outcomes discussed. Indications exist that for some outcomes, UVB effects may be independent of vitamin D. This paper discusses the concept of the ecological fallacy, noting that it applies to all epidemiological studies.