BACKGROUND: We aimed to describe healthcare resource utilization (HCRU) and healthcare costs in patients with newly confirmed lupus nephritis (LN) in the United States over a 5-year follow-up period.
METHODS: This retrospective, longitudinal cohort study (GSK Study 214102) utilized administrative claims data to identify individuals with a newly confirmed diagnosis of LN between August 01, 2011, and July 31, 2018, based on LN-specific International Classification of Diseases diagnosis codes. Index was the date of first LN-related diagnosis code claim. HCRU, healthcare costs, and incidence of systemic lupus erythematosus (SLE) flares were reported annually among eligible patients with at least 5 years continuous enrollment post-index.
RESULTS: Of 2,159 patients with a newly confirmed diagnosis of LN meeting inclusion and exclusion criteria, 335 had at least 5 years continuous enrollment post-index. HCRU was greatest in the first year post-LN diagnosis across all categories (inpatient admission, emergency room [ER] visits, ambulatory visits, and pharmacy use), and trended lower, though remained substantial, in the 5-year follow-up period. Among patients with LN and HCRU, the mean (standard deviation [SD]) number of ER visits and inpatient admissions were 3.7 (4.6) and 1.8 (1.5), respectively, in Year 1, which generally remained stable in Years 2-5; the mean (SD) number of ambulatory visits and pharmacy fills were 35.8 (25.1) and 62.9 (43.8), respectively, in Year 1, and remained similar for Years 2-5. Most patients (≥ 91.6%) had ≥ 1 SLE flare in each of the 5 years of follow-up. The proportion of patients who experienced a severe SLE flare was higher in Year 1 (31.6%) than subsequent years (14.3-18.5%). Total costs (medical and pharmacy; mean [SD]) were higher in Year 1 ($44,205 [71,532]) than subsequent years ($29,444 [52,310]-$32,222 [58,216]), driven mainly by inpatient admissions (Year 1: $21,181 [58,886]; subsequent years: $7,406 [23,331]-$9,389 [29,283]).
CONCLUSIONS: Patients with a newly confirmed diagnosis of LN have substantial HCRU and healthcare costs, particularly in the year post-diagnosis, largely driven by inpatient costs. This highlights the need for improved disease management to prevent renal damage, improve patient outcomes, and reduce costs among patients with renal involvement.

BACKGROUND: Systemic lupus erythematosus (SLE) causes kidney compromise in up to 40% of patients, contributing significantly to morbidity. Lupus nephritis (LN), an early onset manifestation in most patients, is histologically classified into six types, with types III, IV, and V requiring treatment with induction therapies, usually glucocorticoids with mycophenolate mofetil (MMF) or intravenous cyclophosphamide (IVC). However, up to 60% of patients fail to achieve complete remission, and 27%-66% have subsequent flares. There is scarce literature on the superiority of IVC or MMF in the Latin population.
METHODS: A retrospective cohort study of 72 LN patients at a high-complexity hospital in Chile between 2016 and 2021 was conducted. Demographics, urine studies, creatinine levels, complement levels, antibody profiles, biopsy results, and response to treatment were analysed.
RESULTS: The median age of the cohort was 29 years, with women representing 90% of patients. At diagnosis, 87.5% of the patients presented with proteinuria, 55% had haematuria, and 49% had acute kidney injury. The most common LN type was type IV. For induction therapy, half of the patients were treated with IVC, and the other half with MMF. The response to treatment did not differ significantly between the two.
CONCLUSIONS: This is one of the few studies to focus on the Latin American population, specifically Chile. These results are consistent with the current understanding of LN treatment. Despite its limitations, this study provides valuable insights into the treatment effectiveness of IVC and MMF in this population.
CONCLUSIONS: This study did not find significant differences in the clinical response to IVC or MMF at 6 months. Future prospective studies are required to determine the optimal induction therapy for LN, especially in Latin populations.

OBJECTIVE: This study aimed to investigate the role of the programmed cell death protein 1 (PD-1) pathway and T peripheral helper (Tph) cells in the pathogenesis of lupus nephritis using lupus-prone BXSB-Yaa mice.
METHODS: Male BXSB-Yaa mice and age-matched male C57BL/6 mice were used. The expression of PD-1 and its ligands (programmed cell death 1 ligand-1, PD-L1 and programmed cell death 1 ligand-2, PD-L2) and the phenotypes of kidney-derived cells and splenocytes expressing these molecules were analyzed by immunofluorescence and flow cytometry.
RESULTS: Nephritis spontaneously developed in 16-week-old but not in 8-week-old BXSB-Yaa or C57BL/6 mice. PD-1 was expressed on CD4+ mononuclear cells (MNCs) that infiltrated the glomeruli of 16-week-old BXSB-Yaa mice. The frequency of CD4+PD-1+CXCR5-ICOS+ kidney-derived Tph cells was higher in 16-week-old than in 8-week-old BXSB-Yaa and C57BL/6 mice, whereas the frequency of CD4+PD-1+CXCR5+ICOS+ kidney-derived T follicular helper (Tfh) cells was not significantly different between the mice. PD-L1 was constitutively expressed in the renal tubules. PD-L2 was expressed in the glomeruli of 16-week-old BXSB-Yaa mice. The frequency of PD-L1highCD11c+CD3-CD19- and PD-L2+CD11c+CD3-CD19- kidney-derived MNCs in 16-week-old BXSB-Yaa mice was significantly higher than that of the control mice. The percentage of kidney-derived Tph cells but not Tfh cells was correlated with the urinary protein levels in the nephritic mice.
CONCLUSIONS: The results of this study suggest that kidney-infiltrating PD-1+ Tph cells expanded concomitantly with the upregulation of PD-L1 and PD-L2 in the kidneys and the progression of lupus nephritis.

BACKGROUND: Although RT has improved the survival of the population with ESRD due to all causes, renal outcomes in SLE are controversial. The objective of this study is to describe the characteristics and evolution of the patients and the kidney transplant in LN, and compare it with patients transplanted for other causes.
METHODS: Retrospective, observational, analytical, single-center study in which records of patients undergoing nephrotransplantation for LN were analyzed. They were compared with a group of patients transplanted at the same center for other causes of ESRD.
RESULTS: 41 patients with kidney transplant due to SLE and 89 transplanted due to other causes of ESRD were registered. Graft loss occurred in 12 (29.26%) patients with LN and 34 (38.2%) patients in the comparison group (p = .428). Only one case (4.8%) presented reactivation of the LN in the graft, without graft loss. Median graft survival was 73.1 months in the LN group and 66.3 months in the comparison group (p = .221). A total of 8 (19.5%) patients with LN and 11 (12.4%) without LN died (p = .42), with infections being the main cause in both groups. There were no statistically significant differences between groups in graft and patient survival. In a sub-analysis of 28 patients with LN with aPL study, 4 thrombotic events were observed, in 3 different patients, in the aPL-positive group. There were no statistically significant differences in terms of causes of graft loss and graft survival (positive aFL 75.7 months vs negative aFL 72.7 months, p= .96). There were also no differences in mortality between the groups (p = .61).
CONCLUSIONS: Patients transplanted for LN did not differ from the control population in terms of graft and patient survival. Infections were the main cause of death, so prophylaxis and vaccination continue to be a fundamental pillar in the prevention of infections in immunocompromised patients.

OBJECTIVE: Lupus nephritis (LN) is a major cause of morbidity and mortality in systemic lupus erythematosus (SLE). Despite multiple studies addressing healthcare disparities, disparate outcomes in LN persist. We investigate herein the association between socioeconomic status (SES) and LN as well as the association between SES, SLE disease activity index (SLEDAI), and treatment response.
METHODS: Patients were selected from the Southern California Lupus Registry (SCOLR), a registry enrolling all-comers with SLE. Analysis was completed on individuals with public vs. private insurance. Insurance and ethnicity were used as surrogate variables for SES, and we tested differences in means.
RESULTS: After adjusting for age and sex, public insurance was independently associated with the prevalence of LN. Analysis of 35 patients revealed greater proteinuria and mean SLEDAI in patients with public insurance at baseline and 6 months. Baseline, 6-, and 12-month SLEDAI means were significantly lower in Asian/Pacific Islanders (PI) compared to others. While non-Hispanic Whites demonstrated mean SLEDAI improvement over 6 months, Asians/PI, Blacks, and Hispanics demonstrated worsened disease activity on average.
CONCLUSIONS: Low SES, when defined by insurance, is associated with greater adverse outcomes in SLE. This is the first regional study that compares differences in treatment response in LN patients with low SES as well as association of SES with long-term outcomes in SLE and LN in southern California.

OBJECTIVE: For the majority of patients with lupus nephritis-related end-stage kidney disease (LN-ESKD), kidney transplant is associated with better outcomes than dialysis. Access to kidney transplant requires an initial referral to a transplant center and medical evaluation prior to waitlisting. The study\'s objective was to examine access to these early steps in the kidney transplant process among patients with LN-ESKD.
METHODS: Adults who began treatment for ESKD in the Southeast, Northeast, New York, or Ohio River Valley U.S. regions from 1/1/2012 to 12/31/2019, followed through 6/30/2021, were identified from the United States Renal Data System. Referral and evaluation start data were collected from 28 of 48 transplant centers across these regions. The exposure was primary cause of ESKD (LN-ESKD vs other-ESKD). The outcomes were referral and evaluation start at a transplant center. Cox models quantified the association between LN-ESKD (vs other-ESKD) and referral and evaluation start.
RESULTS: Among 192,318 patients initiating treatment for ESKD, 0.4% had LN-ESKD. Over half (58%) of LN-ESKD patients were referred before study end, and among those referred, 66% started the evaluation. In adjusted analyses, patients with LN-ESKD were referred (HR: 1.09, 95% CI: 0.99, 1.19) and started the transplant evaluation (HR: 1.13, 95% CI: 1.00, 1.28) at a higher rate than patients with other-ESKD. Among referred patients with LN-ESKD, the median time from ESKD start to referral was 2.9 months (IQR: <1 to 11.7 months), which is similar to patients with other-ESKD (median 2.6 months, IQR: <1 to 8.8 months).
CONCLUSIONS: Among incident patients with ESKD, having a primary diagnosis of LN-ESKD versus other-ESKD is associated with higher rates of early transplant access outcomes. Despite this, patients with LN-ESKD (vs other-ESKD) are less likely to be preemptively referred (i.e., referred prior to ESKD start) for kidney transplant. While providers may no longer be delaying the early steps in the kidney transplantation process among this patient population, there is still room for improvement in the rates of preemptive referral. Access to kidney transplant referral prior to ESKD could result in increased transplant rates and better transplant outcomes for patients with LN-ESKD.

BACKGROUND: Although rare, severe systemic lupus erythematosus (SLE) flares requiring hospitalization account for most of the direct costs of SLE care. New machine learning (ML) methods may optimize lupus care by predicting which patients will have a prolonged hospital length of stay (LOS). Our study uses a machine learning approach to predict the LOS in patients admitted for lupus flares and assesses which features prolong LOS.
METHODS: Our study sampled 5831 patients admitted for lupus flares from the National Inpatient Sample Database 2016-2018 and collected 90 demographics and comorbidity features. Four machine learning (ML) models were built (XGBoost, Linear Support Vector Machines, K Nearest Neighbors, and Logistic Regression) to predict LOS, and their performance was evaluated using multiple metrics, including accuracy, receiver operator area under the curve (ROC-AUC), precision-recall area under the curve (PR- AUC), and F1-score. Using the highest-performing model (XGBoost), we assessed the feature importance of our input features using Shapley value explanations (SHAP) to rank their impact on LOS.
RESULTS: Our XGB model performed the best with a ROC-AUC of 0.87, PR-AUC of 0.61, an F1 score of 0.56, and an accuracy of 95%. The features with the most significant impact on the model were \"the need for a central line,\" \"acute dialysis,\" and \"acute renal failure.\" Other top features include those related to renal and infectious comorbidities.
CONCLUSIONS: Our results were consistent with the established literature and showed promise in ML over traditional methods of predictive analyses, even with rare rheumatic events such as lupus flare hospitalizations.

BACKGROUND: To determine the safety and efficacy of biological agents used in the treatment of systemic lupus erythematosus (SLE) in adults.
METHODS: Systematic review and meta-analysis following PRISMA guidelines.
METHODS: MEDLINE (through Pubmed), EMBASE, Cochrane library, Clinicaltrials.gov, Australianclinicaltrials.gov.au, ANZCTR.org.au and WHO International Clinical Trials Registry Platform for studies published from 20 May 2021 and 15 years prior. A grey literature search was performed and completed on 31 May 2021.
UNASSIGNED: Phase II, III or quasi randomised controlled trials, studies with only cerebral or cutaneous lupus were excluded.
METHODS: Two authors independently screened studies for eligibility, extracted, reviewed data for accuracy, and used the Cochrane tool to assess risk of bias.
RESULTS: Forty-four studies were identified, consisting of 15 groups of drugs and 25 different biological agents, totalling 16,889 patients. The main outcomes assessed included Systemic Lupus Erythematosus Responder Index (SRI), BILAG-Based Composite Lupus Assessment (BICLA) and combined combined/partial renal remission (CRR/PRR). Four groups of biologics were found to improve outcomes. Anti-interferons: Anifrolumab increased BICLA response and SRI 5 to 8, decreased prednisone dosages, with increased herpes zoster infections, but fewer serious adverse events. Sifalimumab improved SRI but also increased herpes zoster infections. Anti BAFF/BLyS and/or APRIL: Belimumab consistently improved SRI 4, decreased prednisone dosages, increased combined CRR/PRR, and had no adverse safety outcomes. Tabalumab increased SRI 5 at 52 weeks with no steroid sparing effect but was associated with increased infusion related adverse events. Telitacicept improved SRI 4 at 52 weeks, with no increased adverse events, though data was rather sparse. Anti CD-20 monoclonal antibody, Obinutuzumab increased combined CRR/PRR at 1 and 2 years. Anti IL12/23 monoclonal antibody, Ustekinumab, increased SRI 4 to 6, but not BICLA at 24 weeks, with no concerning safety outcomes.
CONCLUSIONS: Multiple biologic agents are shown in high quality studies to have a significant therapeutic impact on outcomes in SLE.

Lupus nephritis (LN) is a major course of morbidity and mortality in patients with systemic lupus erythematosus (SLE), best managed by a multidisciplinary group. To this end, we gathered a group of rheumatologists, nephrologists and a nephropathologist to review current evidence regarding diagnosis and management of LN. In this consensus paper, we summarize the key points from this meeting and provide practice guidelines for the management of kidney involvement in SLE, in view of emerging new data concerning novel agents approved recently. Renal biopsy is indispensable for the management of LN. Yet, important pearls and pitfalls need to be considered regarding indications and interpretation, which are summarized in informative tables. In new-onset LN, experts agreed that, although belimumab may be added from disease onset, patients with moderate to severe proliferative nephritis (defined as: NIH activity index > 5 plus ≥ 1 of the following: (i) NIH chronicity index > 2, (ii) proteinuria > 3 g/24 h, and (iii) increase in serum creatinine > 20%) may be more likely to benefit the most. In all other patients who have already started standard-of-care treatment with either mycophenolate mofetil (MMF) or cyclophosphamide (CY), belimumab could be considered in cases with an inadequate clinical response by 3 months, or in cases that experience a nephritic flare following initial response, or have an inability to reduce the dose of glucocorticoids. In all circumstances, the drug should be given as add-on therapy, that is, in combination with a standard-of-care therapy (MMF or CY). Voclosporin could be considered for up to 3 years, in combination with MMF, in patients with heavy proteinuria (well above the nephrotic range), wherein a quick reduction of protein loss in urine is desirable to avoid the complications of the nephrotic syndrome, either as part of the initial regimen, or in cases of inadequate reduction of proteinuria with MMF. In view of the potential scarring effects, long-term administration beyond the first year requires further documentation.

In women of childbearing age, severe proteinuria in systemic lupus erythematosus raises concern for renal involvement and pregnancy complications. While persisting renal loss of protein is known to culminate in extensive interventions, intermittent proteinuria in inactive disease requires an adjusted approach. Contextual awareness of this urinary finding is thus essential.