Kidney Biopsy in Management of Lupus Nephritis: A Case-Based Narrative Review

Kidney involvement in patients with lupus highly increases morbidity and mortality. In recent years, several reports have emphasized the dissociation between clinical and histological findings and highlighted the role of kidney biopsy as an instrument for diagnosis and follow-up of lupus nephritis. The kidney biopsy at initial diagnosis allows an early diagnosis, assessment of activity and chronicity, and detection of nonimmune complex nephritis. A kidney biopsy repeated months after treatment aids in the detection of persistent histological inflammation, which has been linked to the occurrence of future kidney relapses. A kidney biopsy at a relapse detects histological changes including chronic scarring. Finally, a kidney biopsy in patients with a clinical response undergoing maintenance immunosuppression may aid therapy tapering and/or suspension. The evidence supporting the use of a kidney biopsy in different scenarios across the course of lupus nephritis is heterogeneous, with most reports assessing the value for the diagnosis of a first or relapsing flare. In contrast, less evidence suggests additional therapeutic-modifying information derived from repeat posttreatment biopsies and biopsies to evaluate treatment tapering or suspension. In this clinical case-based review, we examine the role of kidney biopsy as a tool to improve clinical outcomes of patients with lupus nephritis.

Epidemiology and Outcomes of Glomerular Diseases in Low- and Middle-Income Countries

Glomerular diseases account for a significant proportion of chronic kidney disease in low-income and middle-income countries (LMICs). The epidemiology of glomerulonephritis is characterized inadequately in LMICs, largely owing to unavailable nephropathology services or uncertainty of the safety of the kidney biopsy procedure. In contrast to high-income countries where IgA nephropathy is the dominant primary glomerular disease, focal segmental glomerulosclerosis is common in large populations across Latin America, Africa, Middle East, and South East Asia, while IgA nephropathy is common in Chinese populations. Despite having a high prevalence of known genetic and viral risk factors that trigger focal segmental glomerulosclerosis, membranoproliferative glomerulonephritis also is common in adults and children in some African countries. Treatment of glomerular diseases in adults and children in LMICs largely is dependent on corticosteroids in combination with other immunosuppressive therapy, which often is cyclophosphamide because of its ready availability and low cost of treatment, despite significant adverse effects. Partial and/or complete remission status reported from studies of glomerular disease subtypes vary across LMIC regions, with high rates of kidney failure, mortality, and disease, and treatment complications often reported. Improving the availability of nephropathology services and ensuring availability of specific therapies are key measures to improving glomerular disease outcomes in LMICs.

The influence of repeated flares in response to therapy and prognosis in lupus nephritis

Background

Repeated renal flares in lupus nephritis (LN) have been associated with worse long-term kidney function. This study aimed to assess the impact of repeated LN flares in response to therapy, kidney and patient prognosis.

Methods

All patients from a biopsy-proven LN cohort between 2008 and 2018 were segregated into three groups according to the number of LN flares when they entered our cohort: first LN flare, second LN flare or third LN flare. The following outcomes were evaluated by unadjusted and adjusted time-to-event analyses: complete and partial response, disease relapses, progression to decline of 30% of the estimated glomerular filtration rate (eGFR), doubling of serum creatinine, end-stage kidney disease and patient survival.

Results

A total of 441 patients were included: 257 (58%) in their first LN flare, 102 (23%) in their second LN flare and 82 (19%) in their third LN flare. There were significant differences in LN flare presentation in age, eGFR, serum albumin, pyuria and hematuria among groups. The National Institutes of Health chronicity indices and the percentage of patients with vascular lesions were higher in groups at progressive LN flares. In the adjusted analyses, complete and partial response rates decreased, as well as kidney and patient survival, at a progressive number of LN flares. No differences in the dynamic course of all surveillance laboratory parameters were observed in the first year after initial therapy among LN flare groups.

Conclusions

A progressive number of LN flares is associated with a lower response to therapy and an adverse prognosis for kidney function and patient survival.

Treatment outcomes in refractory lupus nephritis: Data from an observational study

OBJECTIVES

Despite current advances in treatment, refractory lupus nephritis (RLN) continues to pose a challenge. The present paper studies the clinical profile and treatment outcomes in patients with RLN.

METHODS

This observational, bidirectional study enrolled consecutive lupus nephritis (LN) patients from August 2018 to January 2019, who either failed to improve within three months, did not achieve partial renal response (PR) at six months, or did not achieve complete renal response (CR) after two years of treatment. Patients were followed every three months; treatment details and outcomes [CR, PR, no renal response (NR)], doubling serum creatinine, and death were recorded. Group comparisons were made using ANOVA and chi-square test. Factors affecting renal response were studied using linear regression.

RESULTS

Forty-five of forty-eight enrolled patients completed at least nine months of follow-up and were included in outcome analysis. The median (IQR) SLE duration was three years (2-6 years). The majority of patients (n = 25) had proliferative LN (ISN/RPS class III/IV), with nine patients having pure membranous LN (class V). The mean activity and chronicity indices were 8 and 0. Over a median (IQR) follow-up period of 15 (12-27) months, 28 had CR, 9 had PR, and 8 showed no response to a switch in an immunosuppressive (IS) agent. Repeat renal biopsy (n = 8) with a mean (±SD) biopsy interval of 2 (±1) years showed histological class transformation in more than half of the patients. There was no significant difference in treatment outcome and time to attain response based on individual IS agent or sequence of IS agents used. None of the variables (duration of SLE or nephritis, baseline SLEDAI, leukopenia, hypertension, elevated anti-dsDNA, low complements, serum albumin, 24-hour urinary protein, biopsy class) predicted renal response on univariate analysis. No patient had a doubling of serum creatinine or progression to end-stage renal disease. There were three deaths, all related to infection.

CONCLUSION

A change in immunosuppression produces response in most RLN patients while a fifth of them showed no response to therapy. No predictor of renal response was identified. Histologic class switch was frequent. Renal function did not decline over a year of follow-up.

What is the value of repeat kidney biopsies in patients with lupus nephritis?

INTRODUCTION

Recent studies with protocol biopsies have shown a mismatch between clinical and histological remission in lupus nephritis (LN). We aimed to evaluate histological changes in repeat kidney biopsies by clinical indication in patients with LN.

METHODS

We analyzed 107 patients with LN in which a kidney biopsy was performed between 2008 and 2018. Of those, we included 26 (24.2%) who had ≥2 kidney biopsies. Classification was done according to the International Society of Nephrology/Renal Pathology Society.

RESULTS

Mean time between biopsies was 71.5 ± 10.7 months. 73.1% of patients presented a change of class at repeat biopsy; 38.4% to a higher class and 34.6% to a lower class. A significant increase in glomerulosclerosis (% GS) (3.8% vs 18.7%, p = 0.006), interstitial fibrosis (3.8% vs 26.9%, p = 0.021), tubular atrophy (15.4% vs 57.7%, p = 0.001) and chronicity index (CI) (1 vs 3, p < 0.001) was observed at repeat biopsy. Subjects who developed chronic kidney disease progression had a lower rate of complete remission at 12 months (0% vs 37.5%, p = 0.02), higher % GS at first biopsy (7.9% vs 1.2%, p = 0.02) and higher CI (4 vs 2, p = 0.006), tubular atrophy (90% vs 37.6%, p = 0.008), interstitial fibrosis (50% vs 12.5%, p = 0.036) and vascular lesions (60% vs 18.8%, p = 0.031) at second biopsy.

CONCLUSIONS

Our major finding was that patients with LN showed a significant increase in % GS, interstitial fibrosis, tubular atrophy and vascular lesions in repeat biopsies performed by clinical indication. This suggest that a second kidney biopsy may provide valuable and useful information regarding kidney disease progression.

Systemic lupus erythematosus, lupus nephritis and end-stage renal disease: a pragmatic review mapping disease severity and progression

Objective

The understanding of systemic lupus erythematosus (SLE) and lupus nephritis (LN) pathogenesis remains incomplete. This review assessed LN development in SLE, within-LN progression and progression to end-stage renal disease (ESRD).

Methods

A keyword-based literature search was conducted, and 26 publications were included.

Results

Overall, 7–31% of patients had LN at SLE diagnosis; 31–48% developed LN after SLE diagnosis, most within 5 years. Class IV was the most commonly found LN class and had the worst prognosis. Histological transformation occurred in 40–76% of patients, more frequently from non-proliferative rather than proliferative lesions. Cumulative 5- and 10-year ESRD incidences in patients with SLE were 3% and 4%, respectively, and 3–11% and 6–19%, respectively, in patients with SLE and LN.

Conclusions

Elevated serum creatinine was identified as a predictor of worsening disease state, and progression within LN classes and from SLE/LN to ESRD. This review highlights the substantial risk for developing LN and progressing to ESRD amongst patients with SLE.

Stellenwert der Nierenbiopsie bei Lupusnephritis

Bei systemischem Lupus erythematodes (SLE) findet sich häufig eine renale Mitbeteiligung, der verschiedene pathogenetische Mechanismen zugrunde liegen. Die Nierenbeteiligung hat einen negativen Einfluss auf die Prognose des SLE, insbesondere bei progredienter Niereninsuffizienz. Eine Nierenbiopsie ist aufgrund der Heterogenität der Nierenbeteiligung und der damit verbundenen therapeutischen Konsequenzen unabdingbar. Sie kann durch nicht-invasive Untersuchungen wie die Urindiagnostik oder Serologie nicht ersetzt werden, da das Ausmaß der Proteinurie oder der Mikrohämaturie keine sicheren Rückschlüsse auf den Schweregrad, die Pathogenese und die Prognose der Nierenbeteiligung erlauben. Die Nierenbiopsie gibt neben der korrekten Klassifikation der Lupusnephritis (LN) Informationen über die Mitbeteiligung des Niereninterstitium, der intrarenalen Gefäße und der Aktivität sowie Chronizität der Nephritis. Auch kann der Pathologe die Frage beantworten, inwieweit mit einer Besserung der Nierenfunktion unter Therapie gerechnet werden kann. Der folgende Beitrag gibt einen Überblick über den Stellenwert der Nierenbiopsie bei SLE, der revidierten Klassifikation der LN von 2018 einschließlich Sonderformen der LN und über die Implikationen des Biopsie-Ergebnisses für die Therapie.