Lupus Nephritis and Kidney Transplantation: Where Are We Today?

Predicting wait time for pediatric kidney transplant: a novel index

BACKGROUND

Over one thousand pediatric kidney transplant candidates are added to the waitlist annually, yet the prospective time spent waiting is unknown for many. Our study fills this gap by identifying variables that impact waitlist time and by creating an index to predict the likelihood of a pediatric candidate receiving a transplant within 1 year of listing. This index could be used to guide patient management by giving clinicians a potential timeline for each candidate's listing based on a unique combination of risk factors.

METHODS

A retrospective analysis of 3757 pediatric kidney transplant candidates from the 2014 to 2020 OPTN/UNOS database was performed. The data was randomly divided into a training set, comprising two-thirds of the data, and a testing set, comprising one-third of the data. From the training set, univariable and multivariable logistic regressions were used to identify significant predictive factors affecting wait times. A predictive index was created using variables significant in the multivariable analysis. The index's ability to predict likelihood of transplantation within 1 year of listing was validated using ROC analysis on the training set. Validation of the index using ROC analysis was repeated on the testing set.

RESULTS

A total of 10 variables were found to be significant. The five most significant variables include the following: blood group, B (OR 0.65); dialysis status (OR 3.67); kidney disease etiology, SLE (OR 0.38); and OPTN region, 5 (OR 0.54) and 6 (OR 0.46). ROC analysis of the index on the training set yielded a c-statistic of 0.71. ROC analysis of the index on the testing set yielded a c-statistic of 0.68.

CONCLUSIONS

This index is a modest prognostic model to assess time to pediatric kidney transplantation. It is intended as a supplementary tool to guide patient management by providing clinicians with an individualized prospective timeline for each candidate. Early identification of candidates with potential for prolonged waiting times may help encourage more living donation including paired donation chains.

II Brazilian Society of Rheumatology consensus for lupus nephritis diagnosis and treatment

OBJECTIVE

To develop the second evidence-based Brazilian Society of Rheumatology consensus for diagnosis and treatment of lupus nephritis (LN).

METHODS

Two methodologists and 20 rheumatologists from Lupus Comittee of Brazilian Society of Rheumatology participate in the development of this guideline. Fourteen PICO questions were defined and a systematic review was performed. Eligible randomized controlled trials were analyzed regarding complete renal remission, partial renal remission, serum creatinine, proteinuria, serum creatinine doubling, progression to end-stage renal disease, renal relapse, and severe adverse events (infections and mortality). The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to develop these recommendations. Recommendations required ≥82% of agreement among the voting members and were classified as strongly in favor, weakly in favor, conditional, weakly against or strongly against a particular intervention. Other aspects of LN management (diagnosis, general principles of treatment, treatment of comorbidities and refractory cases) were evaluated through literature review and expert opinion.

RESULTS

All SLE patients should undergo creatinine and urinalysis tests to assess renal involvement. Kidney biopsy is considered the gold standard for diagnosing LN but, if it is not available or there is a contraindication to the procedure, therapeutic decisions should be based on clinical and laboratory parameters. Fourteen recommendations were developed. Target Renal response (TRR) was defined as improvement or maintenance of renal function (±10% at baseline of treatment) combined with a decrease in 24-h proteinuria or 24-h UPCR of 25% at 3 months, a decrease of 50% at 6 months, and proteinuria < 0.8 g/24 h at 12 months. Hydroxychloroquine should be prescribed to all SLE patients, except in cases of contraindication. Glucocorticoids should be used at the lowest dose and for the minimal necessary period. In class III or IV (±V), mycophenolate (MMF), cyclophosphamide, MMF plus tacrolimus (TAC), MMF plus belimumab or TAC can be used as induction therapy. For maintenance therapy, MMF or azathioprine (AZA) are the first choice and TAC or cyclosporin or leflunomide can be used in patients who cannot use MMF or AZA. Rituximab can be prescribed in cases of refractory disease. In cases of failure in achieving TRR, it is important to assess adherence, immunosuppressant dosage, adjuvant therapy, comorbidities, and consider biopsy/rebiopsy.

CONCLUSION

This consensus provides evidence-based data to guide LN diagnosis and treatment, supporting the development of public and supplementary health policies in Brazil.

Lupus nephritis: management challenges during pregnancy

Lupus nephritis (LN), a severe complication of systemic lupus erythematosus (SLE), leads to significant kidney inflammation and damage and drastically increases mortality risk. Predominantly impacting women in their reproductive years, LN poses specific risks during pregnancy, including pre-eclampsia, growth restrictions, stillbirth, and preterm delivery, exacerbated by lupus activity, specific antibodies, and pre-existing conditions like hypertension. Effective management of LN during pregnancy is crucial and involves carefully balancing disease control with the safety of the fetus. This includes pre-conception counseling and a multidisciplinary approach among specialists to navigate the complexities LN patients face during pregnancy, such as distinguishing LN flare-ups from pregnancy-induced conditions. This review focuses on exploring the complex dynamics between pregnancy and LN, emphasizing the management difficulties and the heightened risks pregnant women with LN encounter.

From systemic lupus erythematosus to lupus nephritis: The evolving road to targeted therapies

Systemic lupus erythematosus is a chronic autoimmune disease characterized by loss of tolerance against nuclear and cytoplasmic self-antigens, induction of immunity and tissue inflammation. Lupus nephritis (LN), the most important predictor of morbidity in SLE, develops in almost 30% of SLE patients at disease onset and in up to 50-60% within the first 10 years. Firstly, in this review, we put the pathogenic mechanisms of the disease into a conceptual frame, giving emphasis to the role of the innate immune system in this loss of self-tolerance and the induction of the adaptive immune response. In this aspect, many mechanisms have been described such as dysregulation and acceleration of cell-death pathways, an aberrant clearance and overload of immunogenic acid-nucleic-containing debris and IC, and the involvement of antigen-presenting cells and other innate immune cells in the induction of this adaptive immune response. This result in a clonal expansion of autoreactive lymphocytes with generation of effector T-cells, memory B-cells and plasma cells that produce autoantibodies that will cause kidney damage. Secondly, we review the immunological pathways of damage in the kidney parenchyma, initiated by autoantibody binding and immune complex deposition, and followed by complement-mediated microvascular injury, activation of kidney stromal cells and the recruitment of leukocytes. Finally, we summarize the rationale for the treatment of LN, from conventional to new targeted therapies, focusing on their systemic immunologic effects and the minimization of podocytary damage.

Lupus nephritis - An update on disparities affecting african americans

Lupus Nephritis is a complex clinical manifestation of systemic lupus erythematosus (SLE) associated with significant morbidity and mortality. It disproportionately affects minorities, especially African Americans (AA) with higher rates of progression to end stage kidney disease. Several factors are implicated including genetic predisposition to both SLE and chronic kidney disease, social determinants of health such as income inequality, education disparities, social isolation/lack of support, health care access and affordability. Clinically, AA may have higher auto-antibody titers, including several antibodies occurring simultaneously. AA are more prone to severe disease such as Class III and IV lupus nephritis. Fortunately, clinical trials have shown a favorable benefit/response among African Americans to mycophenolate mofetil. However, newer and alternative agents such as Rituximab, Belimumab and Voclosporin are widely unaffordable, and AA remain underrepresented in these clinical trials. The current state of disparities affecting LN patients of AA ancestry is a call for better access to healthcare and social support systems, greater inclusion/representation in clinical trials, and making new and alternative regimens more affordable and cost effective.

Kidney transplantation in pediatric patients with rheumatologic disorders

PURPOSE OF REVIEW

Providers caring for children with end-stage kidney disease from rheumatologic conditions face questions such as when to proceed with kidney transplantation, how common is disease recurrence posttransplant, how does recurrent disease impact patient and allograft outcomes, and what approaches are available to prevent and treat recurrent disease. We discuss recent developments and relevant literature that address these questions for the most common rheumatologic disorders that lead to end-stage kidney disease in childhood namely, systemic lupus erythematosus, IgA nephropathy, IgA Vasculitis/Henoch Schoenlein Purpura, and Anti-Neutrophil Cytoplasmic Antibody (ANCA)-associated vasculitis.

RECENT FINDINGS

Recent data suggest that children with IgA nephropathy, IgA vasculitis, and ANCA-associated vasculitis have similar patient and allograft survival to other conditions despite the risk of recurrent disease, yet those with lupus have worse posttransplant patient and allograft outcomes. A period of disease quiescence may be prudent prior to transplantation to decrease the risk of recurrence, which is associated with decreased allograft survival. Data on preventive strategies and treatment options are limited.

SUMMARY

It is recommended that patients with systemic rheumatologic conditions not be excluded from kidney transplantation but that patients be counseled on the risk of potential recurrent disease with its impact on transplant outcomes.

Relapse and Outcome of Lupus Nephritis After Renal Transplantation in the Modern Immunosuppressive Era

Background

Recurrence of lupus nephritis in the graft is a concern in lupus patients with end-stage renal disease undergoing renal transplantation. The recurrence of lupus nephritis has been variable among different studies depending on the patient characteristics, immunosuppressive regimen, and indications of renal biopsy. Therefore, we investigated the recurrence of lupus nephritis among our patients to see if the new post-transplant regimen has impacted the recurrence.

Methods

We collected data on all recipients with end-stage renal disease secondary to lupus nephritis, who received renal transplants between 2006-2017 in our center. Patient demographics, transplant, and dialysis-related information have been recorded including kidney biopsy, graft loss, and survival were recorded. An association between recurrent lupus nephritis with survival and/or graft loss was examined using survival models.

Results

The overall mean±SD age at baseline was 42±13 years; 89% were female; 89% were African American; the previous time on dialysis was a median of 4 years (IQR: 2-8 years), 81% received hemodialysis and 31% received living donor transplantation in the cohort. Our patients received the standard immunosuppressive regimen consisting of prednisone, tacrolimus, and mycophenolate mofetil. Four (10.5%) of the 38 patients had biopsy-proven lupus nephritis recurrence. A total of 10 patients (26%) had graft loss or died during the median follow-up time of 1,230 days (IQR: 460-2,227 days). Recurrence of lupus nephritis showed a trend for increased risk of graft loss or patient death (Hazard Ratio: 3.14, 95%Confidence Interval: 0.65-15.24) compared to the recipient without recurrence in our unadjusted proportional Cox regression model.

Conclusion

The recurrence rate of lupus nephritis in our patient population is much lower compared to past studies from different immunosuppressive eras. Patients with recurrent lupus nephritis showed an increased risk of graft loss or death.

Deep Learning-Based Model Significantly Improves Diagnostic Performance for Assessing Renal Histopathology in Lupus Glomerulonephritis

<b><i>Background:</i></b> Assessment of glomerular lesions and structures plays an essential role in understanding the pathological diagnosis of glomerulonephritis and prognostic evaluation of many kidney diseases. Renal pathophysiological assessment requires novel high-throughput tools to conduct quantitative, unbiased, and reproducible analyses representing a central readout. Deep learning may be an effective tool for glomerulonephritis pathological analysis. <b><i>Methods:</i></b> We developed a murine renal pathological system (MRPS) model to objectify the pathological evaluation via the deep learning method on whole-slide image (WSI) segmentation and feature extraction. A convolutional neural network model was used for accurate segmentation of glomeruli and glomerular cells of periodic acid-Schiff-stained kidney tissue from healthy and lupus nephritis mice. To achieve a quantitative evaluation, we subsequently filtered five independent predictors as image biomarkers from all features and developed a formula for the scoring model. <b><i>Results:</i></b> Perimeter, shape factor, minimum internal diameter, minimum caliper diameter, and number of objects were identified as independent predictors and were included in the establishment of the MRPS. The MRPS showed a positive correlation with renal score (<i>r</i> = 0.480, <i>p</i> &#x3c; 0.001) and obtained great diagnostic performance in discriminating different score bands (Obuchowski index, 0.842 [95% confidence interval: 0.759, 0.925]), with an area under the curve of 0.78–0.98, sensitivity of 58–93%, specificity of 72–100%, and accuracy of 74–94%. <b><i>Conclusion:</i></b> Our MRPS for quantitative assessment of renal WSIs from MRL/lpr lupus nephritis mice enables accurate histopathological analyses with high reproducibility, which may serve as a useful tool for glomerulonephritis diagnosis and prognosis evaluation.

Renal function deterioration is an independent mortality determinant in Koreans diagnosed with lupus nephritis

OBJECTIVE

To evaluate the predictors of mortality, mortality rate, and causes of death in patients with lupus nephritis (LN) depending on final renal function.

METHODS

The cohort included 401 Korean patients diagnosed with LN between 1985 and 2019. We retrospectively analyzed the clinical and laboratory indices, treatment response, and the final renal function. The final renal function was defined by the last stable level of eGFR measured in an out-patient department more than 3 times before death occurred and was categorized into five groups depending on CKD stage.

RESULTS

The median follow-up time after the diagnosis of LN was 131 months. No difference in baseline demographic characteristics and laboratory findings was found except for the proportion of Hb less than 10 mg/dl and baseline eGFR (p = 0.011 and 0.037). We found no significant differences in therapeutic parameters, but all the response parameters including treatment response at 6 months (p = 0.004) and 12 months (p = 0.004), time to remission (p < 0.001), final renal response (p < 0.001), and the final renal function (p < 0.001) differed significantly between the two groups. In multivariate Cox proportional hazards analysis, the final renal function was an independent risk factor predicting mortality. The main causes of death were infection and SLE flare. Contrary to existing knowledge, SLE flare also triggered mortality in a few patients with LN progressed to end-stage renal disease (ESRD). Only two cases of mortality occurred in the kidney transplantation (KT) group (n = 25) with a median follow-up period of 224 months. The overall mortality rates calculated using the Kaplan-Meier method were 6.8%, 10.3%, 19.7%, and 28.0% at 5, 10, 20, and 30 years, respectively.

CONCLUSION

Renal function deterioration was an independent determinant of mortality in Korean patients with LN. SLE flare also caused mortality in patients with LN who required maintenance dialysis, suggesting the benefit of KT on lupus activity and survival.

Recurrent Glomerular Diseases in Renal Transplantation with Focus on Role of Electron Microscopy

Background

The common causes of renal transplant complications include active or chronic rejection process, infections, and toxicity but also recurrent or de novo diseases, which play an important role in affecting long-term graft function or graft loss.

Summary

Recurrent disease in renal transplantation is defined as recurrence of the original kidney disease leading to end-stage kidney disease. They comprise a heterogeneous group of predominantly glomerular and some tubulointerstitial and vascular lesions, which include primary kidney diseases (e.g., focal segmental glomerulosclerosis, membranous glomerulonephritis, and IgA nephropathy) or those secondary to systemic autoimmune, metabolic, and infectious processes that can range from subclinical to clinically overt acute, subacute, or chronic clinical presentations. In addition to the knowledge of prior renal disease and routine/periodic serum and urine testing for kidney function, a complete transplant renal biopsy examination is essential in the identification and differentiation of these diseases. The time of onset and severity of these diseases depend on the underlying etiopathogenetic mechanisms and the varied rates of recurrence in the early or late posttransplant period, often being modified by the current immunosuppressive protocols and other donor and recipient predisposing characteristics.

Key Messages

Transplant kidney biopsy findings provide diagnostic accuracy and prognostic information regarding the potential for reversibility along with detection of unsuspected or clinically symptomatic recurrent diseases, with any concomitant rejection process or toxicity, for appropriate therapeutic decision-making. Routine electron microscopy in transplant kidney biopsies is a valuable tool in recognizing fully developed or early/subtle features of evolving recurrent diseases, often during the subclinical phases, in for cause or surveillance allograft biopsies.

Kidney transplantation outcomes in lupus nephritis: A 37-year single-center experience from Latin America

OBJECTIVE

We assessed patient and graft outcomes and prognostic factors in kidney transplantation in patients with end-stage kidney disease (ESKD) secondary to lupus nephritis (LN) undergoing kidney transplantation from August 1977 to December 2014 in a Latin American single center.

METHODS

The primary endpoint was patient survival, and the secondary endpoints were death-censored graft survival for the first renal transplant and the rate of recurrent LN (RLN). Kaplan-Meier method was used for survival analysis. Factors predicting patient and death-censored graft survivals were examined by Cox proportional-hazards regression analyses.

RESULTS

185 patients were retrospectively evaluated. Patient survival rates were 88% at one year, 82% at three years, 78% at five years, and 67% at ten years. Death-censored graft survival for the first renal transplant was 93% at one year, 89% at three years, 87% at five years, and 80% at ten years. RLN was diagnosed in 2 patients (1.08%), but no graft was lost because of RLN. Thirty-nine (21.1%) patients died, and 65 (35.1%) patients experienced graft loss during the follow-up. By multivariable analyses, older recipient age and 1-month posttransplantation eGFR <45 ml/min/1.73m² were associated with lower patient survival and an increased risk of graft loss, while induction immunosuppressive therapy exerted a protective effect on patients' survival. In the subgroup of patients in whom disease activity was measured at the time of transplantation, a higher SLEDAI score was also associated with lower patient survival and an increased risk of graft loss.

CONCLUSION

In a mostly Mestizo population, kidney transplantation is an excellent therapeutic alternative in LN patients with ESKD. Older recipient age, an eGFR <45 ml/min/1.73m² at one month posttransplantation, and disease activity at the time of transplantation are predictive of a lower patient and death-censored graft survival, while induction immunosuppressive therapy has a protective effect on patient survival. RLN is rare and does not influence the risk of graft loss.

Update on Lupus Nephritis: Looking for a New Vision

Lupus nephritis (LN) is one of the most common manifestations of systemic lupus erythematosus (SLE), affecting approximately 40% of patients with lupus. It represents a major risk factor for morbidity and mortality, and 10% of patients with LN will develop end-stage kidney disease (ESKD). Therefore, there are a number of areas for improvement in the field of LN such as the search for new clinical biomarkers with a more accurate correlation with lupus activity and the redefinition of the histological classification into different subgroups in order to guide a personalized treatment. Although the role of protocol repeat kidney biopsies in LN is controversial, recent publications suggest that repeat histological assessment can be useful in guiding therapeutic decisions that may yield toward precision medicine. In the last decade, LN therapy has remained largely unchanged, with a probability of achieving complete or partial remission not exceeding 60-70%. Thus, optimization of old treatment strategies and search for new agents are urgently needed in order to improve outcomes such as mortality or development of ESKD. Future trials should focus in addressing unanswered issues such as the appropriate dose and duration of immunosuppressive treatment, timing of steroid withdrawal, and drug toxicity. In addition, data are still lacking regarding pregnancy and kidney transplantation in LN and knowledge about these important areas is essential for the management of a subset of patients with SLE. In summary, several major gaps are still present in the therapeutic approach and follow-up of patients with LN. The development of new clinical trial designs will be crucial in the search to improve long-term outcomes.