Correlation between the clinical remission and histological remission in repeat biopsy findings of quiescent proliferative lupus nephritis

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.

Is per-protocol kidney biopsy required in lupus nephritis?

Baseline kidney biopsy is recommended in lupus nephritis (LN). Biopsy allows to classify different forms of LN and differentiate other forms of renal involvement, such as tubulo-interstitial nephritis or thrombotic microangiopathy. The indications for repeat biopsy are more controversial. Some authors feel that good clinical monitoring is sufficient to assess prognosis and make therapeutic decisions. Based on the recently demonstrated discordance between clinical and histological response, some physicians recommend per-protocol biopsies either at 6 months in stable patients to verify the response to induction therapy, or after one-to-two years to assess treatment efficacy and tune the duration of maintenance therapy. Others recommend repeating kidney biopsy in case of incomplete response or to discriminate between active and chronic lesions. By definition, a per-protocol kidney biopsy differs from a repeat biopsy in that the former is foreseen at fixed timepoints, regardless of the clinical response. Although any decision should always consider the patient's overall clinical condition, there are no doubts that repeat kidney biopsy represents a useful tool in difficult cases to evaluate treatment response, modulate treatment intensity, and predict long-term renal outcome both in quiescent lupus and during flares. How to harmonize per-protocol biopsies in the LN course remains challenging.

Kidney histopathology in predicting flares following drug withdrawal in proliferative lupus nephritis in clinical remission

Residual renal histopathological activity at clinical remission in Proliferative Lupus Nephritis (PLN) can predict renal flare upon immunosuppression withdrawal. Data on the role of histological renal remission in predicting extra-renal flares is lacking. We assessed renal histopathology prior to drug withdrawal and the occurrence of renal and extra-renal flares over 52 weeks after drug withdrawal in PLN patients in long-term clinical remission. This is a subgroup analysis of a non-inferiority, open-label randomized (1:1) controlled trial. Patients with biopsy-proven Class III/IV LN in the past (biopsy 1), on immunosuppressants (IS) ≥ 3 years, in clinical remission for ≥ 1 year, on stable prednisolone dose (≤ 7.5 mg/day) plus a maintenance IS and hydroxychloroquine (HCQ) were subjected to a repeat renal biopsy (biopsy 2). Individuals with biopsy 2 having activity index (AI) < 4/24 were randomised to either prednisolone or IS withdrawal. Primary end-point was the proportion experiencing a flare [SELENA-SLEDAI flare index (SFI)] at week 52. Twenty-eight eligible patients underwent biopsy 2 and randomized to prednisolone (n = 15) and IS (n = 13) withdrawal. At biopsy 1, 12 (43%) had class III, 15 (53.5%) had class IV, and 1 (3.5%) had class III + V. At biopsy 2, PLN persisted in 4 (14.2%) while 18 (64.2%) were in histological remission (AI = 0) with 6 (21.4%) in class II. Following drug withdrawal, 9/28 (32%) had flares especially musculoskeletal (55.5%), mucocutaneous (44.4%), and renal (33.3%). Among the four persistent PLN patients, one of the two (50%) with AI = 1 had extra-renal flare while both the two with AI = 2 (100%) had renal and extra-renal flares. In those with histological remission (biopsy 2), 6/18 (66.6%) experienced extra-renal flare of whom one also had renal flare. Upon drug withdrawal, renal histopathology findings with any activity index can predict renal flare while histological remission is not enough to predict extra-renal flare, thus making it an unsuitable marker for deep SLE remission.

[Renal manifestations in connective tissue diseases]

Connective tissue diseases (CTD) comprise a group of inflammatory systemic diseases that can affect various organs. Kidney involvement is frequently associated with significant irreversible damage and often before patients become symptomatic. Screening tests of blood and urine as well as clinical vigilance are therefore essential for all CTDs with possible renal involvement. A kidney biopsy is the gold standard for the diagnosis, prognosis and treatment decisions. A common and severe organ involvement in systemic lupus erythematosus (SLE) is glomerulonephritis (GN), also collectively referred to as lupus nephritis (LN). If left untreated LN often leads to end-stage renal failure. The treatment depends on the clinical parameters and histopathology of the renal involvement. Mycophenolate mofetil and cyclophosphamide are potent but nonspecific immunosuppressants which have been available for many years. Recently, new substances specific for LN have also been approved for the first time. Kidney involvement in Sjogren's syndrome has been far less studied. In studies the frequency of renal involvement is still unclear and ranges from 5% to 33%. Tubulointerstitial nephritis (IN) is the typical form of renal involvement which clearly differs from GN in its clinical presentation. Recommendations for treatment are based exclusively on retrospective studies. A renal crisis in systemic scleroderma (SSc) is a rare but feared complication with a high mortality. An antiphospholipid syndrome (APS) nephropathy (APSN) can occur during CTD. These entities are vasculopathies and often thrombotic microangiopathies, which clearly differ from GN and IN in terms of pathophysiology, clinical features and treatment. This article provides an overview of the diversity of the most important renal manifestations of CTDs.

A Histology-Guided Approach to the Management of Patients with Lupus Nephritis: Are We There Yet?

Renal involvement is a frequent complication of systemic lupus erythematosus (SLE). It occurs in up to two-thirds of patients, often early during the disease course, and is the most important predictor of the morbidity and mortality of SLE patients. Despite tremendous improvements in the approach of the lupus nephritis (LN) therapy, including the recent approval of two new disease-modifying therapies, up to 50% of patients do not obtain a renal response and up to 25% will eventually progress to end-stage renal disease (ESRD) within 10 years of diagnosis. Given the lack of correlation between clinical features and histological lesions, there is an increasing need for a histology-guided approach to the management of patients with LN. Apart from the initial diagnosis of type and severity of renal injury in SLE, the concept of a repeat kidney biopsy (either in a for-cause or a per-protocol scenario) has begun to gain increasing popularity in the nephrology community. Herein, we will provide a comprehensive overview of the most important areas of utility of the kidney biopsy in patients with LN.

When and How Is It Possible to Stop Therapy in Patients with Lupus Nephritis: A Narrative Review

Glucocorticoids and other immunosuppressants still represent the cornerstone drugs for the management of SLE and lupus nephritis. The refined use of these drugs over the years has allowed us to obtain stable disease remission and improvement of long-term kidney and patient survival. Nevertheless, a prolonged use of immunosuppressive agents may be accompanied by severe and even life-threatening side effects. Theoretically, a transient or even definitive withdrawal of immunosuppression could be useful to prevent iatrogenic morbidities. For many years, however, the risk of SLE reactivation has held clinicians back from trying to interrupt therapy. In this review, we report the results of the attempts to interrupt glucocorticoids and other immunosuppressive agents in lupus nephritis and in SLE. The available data suggest that therapy withdrawal is feasible at least in patients enjoying a complete clinical remission after a prolonged therapy. A slow and gradual reduction of treatment under medical surveillance is needed to prevent flares of activity. After therapy withdrawal, around one-quarter of patients may have kidney or systemic flares. However, most flares may respond to therapy if rapidly diagnosed. The other patients can enter stable remission for even 20 years or more. The use of antimalarials can help in maintaining the remission after the withdrawal of the immunosuppressive therapy. A repeated kidney biopsy could be of help in deciding to stop therapy, but given the few available data, it cannot be considered essential.