The multifaceted aspects of refractory lupus nephritis

Serum IFN-γ Predicts the Therapeutic Effect of Belimumab in Refractory Lupus Nephritis Patients

Objective

To evaluate belimumabf's efficacy in refractory lupus nephritis (LN) patients and identify predictive serum biomarkers for treatment response.

Methods

In this single-arm retrospective study, we assessed clinical responses in LN patients at baseline and six months after initiating belimumab. Serum cytokines (IL-2, IL-4, IL-6, IL-10, TNF-α, IFN-γ) were quantified using multiplex magnetic bead flow immunoassay before and after treatment.

Results

Fourteen patients with various subtypes of refractory LN participated in the study: seven with class III and V LN, three with type V alone, two with class III, and two with class IV+V and V LN. Post six months of belimumab therapy, all participants exhibited a reduction in the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI)-2K scores from their respective baseline values. Notably, most patients showed a decrease in the dosage of prednisone, levels of 24-hour urinary protein, immunoglobulins, erythrocyte sedimentation rate (ESR), and anti-double-stranded DNA antibody IgM, along with serum levels of IL-4, IL-6, IL-10, and IFN-γ. Meanwhile, levels of C3, C4, IL-2, and TNF-α were observed to increase. Of the participants, nine (64.29%) achieved a complete renal response, one (7.14%) showed a partial response, and four (28.57%) exhibited no response. Significantly, higher baseline serum IFN-γ levels were found in patients who did not achieve complete renal response (CR) compared to those who did (p = 0.009). Receiver operating characteristic (ROC) curve analysis demonstrated that baseline IFN-γ levels had an area under curve (AUC) of 0.96 (0.70-1.00), with a sensitivity of 0.89 and a specificity of 1.00 (p < 0.001).

Conclusion

Belimumab shows potential efficacy in treating refractory LN. Baseline serum IFN-γ levels may predict response to belimumab therapy, potentially enabling more targeted treatment approaches for this challenging condition.

Multifunctional Polydopamine-Based Nanoparticles for Dual-Mode Imaging Guided Targeted Therapy of Lupus Nephritis

Lupus nephritis (LN) is a common and refractory inflammation of the kidneys caused by systemic lupus erythematosus. Diagnosis and therapies at this stage are inefficient or have severe side effects. In recent years, nanomedicines show great potential for imaging diagnosis and controlled drug release. Herein, we developed a polydopamine (PDA)-based nanocarrier modified with Fe₃O₄ and Pt nanoparticles and loaded with necrostatin-1 (Nec-1) for the bimodal imaging and therapy of LN. Results demonstrate that Nec-1/PDA@Pt-Fe₃O₄ nanocarrier exhibits good biocompatibility. Nec-1, as an inhibitor of receptor-interacting protein 1 kinase, can be used to inhibit receptor-interacting protein 1 kinase activity and then reduces inflammation due to LN. Experiments in vitro and in the LN mouse model confirmed that the nanocarrier can reduce neutrophil extracellular traps (NETs) production by RIPK1 and alleviate the progression of inflammation. Previous studies proved that Pt nanoparticles can catalyze H₂O₂ to produce oxygen. A blood oxygen graph of mouse photoacoustic tomography confirmed that Nec-1/PDA@Pt-Fe₃O₄ can generate oxygen to fight against the hypoxic microenvironment of LN. PDA and Fe₃O₄ are used as photographic developers for photoacoustic or magnetic resonance imaging. The preliminary imaging results support Nec-1/PDA@Pt-Fe₃O₄ potential for photoacoustic/magnetic resonance dual-mode imaging, which can accurately and non-invasively monitor microscopic changes due to diseases. Nec-1/PDA@Pt-Fe₃O₄ combining these advantages exhibited outstanding performance in LN imaging and therapy. This work offers valuable insights into LN diagnosis and therapy.

Expert Perspective: An Approach to Refractory Lupus Nephritis

Systemic lupus erythematosus affects the kidneys in ~50% of all patients, and lupus nephritis (LN) is the most common manifestation of kidney involvement. Despite prompt diagnosis and treatment with aggressive immunosuppression, a significant proportion of LN patients do not respond to treatment and are considered to have refractory LN. Several factors other than drug resistance, such as nonadherence to treatment, undertreatment with conventional drugs, the effects of accumulated chronic damage, and genetic factors, may contribute to a poor response to treatment and should be considered. We define refractory LN as no change in (or worsening of) proteinuria and/or estimated glomerular filtration rate in response to 2 different standard-of-care induction regimens after 4-6 months in patients who are adherent to treatment. For patients who have LN that is truly refractory to standard of care, B cell-targeted therapy, specifically rituximab (RTX), is the most common next step. There is limited evidence available on alternative rescue therapies that may be used when there is no response to RTX. These include anti-CD38, leflunomide, intravenous immunoglobulin, plasma exchange, autologous stem cell transplantation, chimeric antigen receptor T cell therapy, anticomplement therapy, and interleukin-2 therapy.

Effectiveness and safety of common therapeutic drugs for refractory lupus nephritis: A network meta-analysis

Previous studies have indicated that various drugs may be beneficial for the treatment of patients with refractory lupus nephritis (RLN). The present study aimed to evaluate the effectiveness and safety of common therapeutic drugs for the treatment of RLN using a network meta-analysis (NMA). NMA was performed using Stata 14.0 software. The odds ratio (OR) and 95% CI were calculated. A total of 19 studies comprising 1,127 patients were included. Common therapeutic drugs for RLN included glucocorticoids (GC), cyclophosphamide (CTX), mycophenolate mofetil (MMF), tacrolimus (TAC), leflunomide (LEF), cyclosporine A and rituximab (RTX). Evaluation of the effectiveness revealed that MMF + GC produced significantly higher overall responses (i.e. complete remission plus partial remission) and that MMF + GC (OR=2.58; 95% CI, 1.67–3.97), CTX + RTX + GC (OR=3.89; 95% CI, 1.60–9.45), CTX + LEF + GC (OR=3.05; 95% CI, 1.05–8.84) and CTX + TAC + GC (OR=6.22; 95% CI, 1.93–20.05) had significantly higher overall responses compared with those to the traditional treatment regimen (CTX + GC). Ranking probability based on the surface under the cumulative ranking curve indicated that CTX + TAC + GC had the highest probability (80.6%) of being the best treatment for achieving an overall response. In the safety evaluation, MMF + GC had a lower risk of infection than CTX + GC (OR=0.32; 95% CI, 0.11,0.88). There were no statistically significant differences in adverse reactions, including gastrointestinal reactions and leukopenia between any two treatment regimens. In conclusion, the regimen of CTX + TAC + GC exhibited a trend in superiority regarding clinical efficacy among common therapeutic drug treatments for RLN, while the regimen of CTX + GC had a higher probability to cause adverse effects among the nine interventions compared.

Changing paradigms in the treatment of systemic lupus erythematosus

SLE poses formidable therapeutic challenges due to its heterogeneity and treatment decisions often cannot be guided by data of high quality. In this review, we attempt to provide insights regarding the treatment of SLE in everyday clinical practice, based on contemporary evidence and our own personal experience. We focus on common therapeutic issues and dilemmas arising in routine care, including monitoring for retinal toxicity associated with hydroxychloroquine, handling of glucocorticoid regimens in order to minimise their adverse events, choice of immunosuppressive medications based on prevailing disease manifestations and optimal use of available biological agents (belimumab and rituximab). We also provide our view on the position of calcineurin inhibitors in the management of lupus nephritis and conclude with remarks on the future perspectives for this challenging disease.

Outcome of participants with nephrotic syndrome in combined clinical trials of lupus nephritis

Objective

The outcome of participants with nephrotic syndrome in clinical trials of lupus nephritis has not been studied in detail.

Methods

Collated data from two randomised controlled trials in lupus nephritis, Lupus Nephritis Assessment of Rituximab (LUNAR) and A Study to Evaluate Ocrelizumab in Patients With Nephritis due to Systemic Lupus Erythematosus (BELONG) were analysed. Nephrotic syndrome was defined as albumin <3 g/dL and urine protein/creatinine ratio ≥3.5 g/g at start of trial. Renal response was defined as a first morning urine protein/creatinine ratio ≤0.5 g/g in addition to ≤25% increase in creatinine from trial entry assessed at week 48. Logistic regression was used to evaluate the association of nephrotic syndrome with renal response while adjusting for treatment received and ACE inhibitor or angiotensin receptor blocker use.

Results

28 (26%) participants with nephrotic syndrome achieved renal response as compared with 130 (52.5%) of those without (p<0.001). Having nephrotic syndrome at baseline significantly lowered the likelihood of achieving renal response (OR 0.32, 95 % CI 0.19 to 0.54, p<0.001). 125 (80%) participants achieved resolution of their nephrotic syndrome in a median time of 16 weeks.

Conclusions

Nephrotic syndrome at baseline decreases the likelihood of renal response at 1 year. Longer clinical trials or better short-term predictors of long-term outcomes may better assess the effect of novel therapeutic approaches on subjects with nephrotic syndrome.

Immunosuppressive Treatment for Lupus Nephritis: Long-Term Results in 178 Patients

Lupus nephritis is one of the most severe Systemic Lupus Erythematosus features, defining treatment modality and prognosis. Our retrospective study, including 178 patients treated for lupus nephritis during 23 years with mostly cyclophosphamide-based initial regimens followed by azathioprine or mycophenolic acid, demonstrates 84.8% of renal response with 19.2% of flares, 15-year patient survival 78.7% and kidney survival 76.3%, and low damage accrual. Both patient and kidney survival significantly differ for subgroups that achieved complete or partial renal response and nonresponders: patient 15-year survival 95% versus 65% versus 35%; kidney 15-year survival 100% versus 58% versus 0%, respectively. 51% (24 out of 47) of patients evaluated at the end of the study period sustained complete renal response; however, only 9 of them had 0 disease activity according to SELENA SLEDAI scale, while 13 patients had scores 2–4 due to the serological abnormalities only. We conclude that (1) initial treatment with cyclophosphamide followed by azathioprine is effective and can be used in agreement with International Guidelines until the evidence for biological treatments benefits becomes available; (2) complete and even partial renal response have positive prognostic value, and failure to achieve renal response negatively influences kidney and patient survival; (3) the validity of complete renal response in SLE is questioned by the absence of conventional definition of SLE remission.

Immunization with pentraxin 3 (PTX3) leads to anti-PTX3 antibody production and delayed lupus-like nephritis in NZB/NZW F1 mice

BACKGROUND

Anti-pentraxin 3 (PTX3) antibodies were associated with the absence of lupus glomerulonephritis in humans.

AIM

To explore the effects of anti-PTX3 antibodies in New Zealand Black/White (NZB/NZW F1) mice and their inherent mechanisms of action.

MATERIALS AND METHODS

30 NZB/NZW F1 mice were subdivided into 3 groups of 10 mice each and subcutaneously injected with PTX3, alum and PBS (group 1), alum and PBS (group 2) or PBS alone (group 3), 3 times 3 weeks apart, before development of renal disease. Mice were followed until natural death. Histological analysis and immunohistochemistry were performed on harvested kidneys. Effects of anti-PTX3 antibodies on C1q binding to immobilized PTX3-anti-PTX3 immune complexes were evaluated in vitro using human SLE sera. Qualitative characterization of human IgG anti-PTX3 was performed.

RESULTS

Only group 1 mice developed anti-PTX3 antibodies. Anti-dsDNA and anti-C1q antibodies appeared significantly later and at lower levels in group 1 mice vs. controls (p < 0.0001). Proteinuria-free and overall survival were significantly increased in group 1 mice vs. controls (p < 0.05 and p = 0.03, respectively). Histopathological analysis showed that glomerular and tubular PTX3 staining and renal lesions were increased in controls compared with immunized mice. Addition of human SLE sera positive for anti-PTX3 antibodies to C1q and fixed PTX3 interfered with C1q binding to PTX3-anti-PTX3 immune complexes. Qualitative characterization of human IgG anti-PTX3 showed an increased proportion of IgG4.

CONCLUSIONS

Anti-PTX3 antibodies delay lupus-like nephritis and prolong survival of NZB/NZW F1 mice. In vitro observations suggest anti-PTX3 antibodies may dampen complement activation via their Fc fragment, likely hindering renal inflammation.

Lupus nephritis: When and how often to biopsy and what does it mean?

Renal disease is a frequent complication of SLE which can lead to significant illness and even death. Today, a baseline renal biopsy is highly recommended for all subjects with evidence of lupus nephritis. Biopsy allows the clinician to recognize and classify different forms of autoimmune lupus glomerulonephritis, and to detect other glomerular diseases with variable pathogenesis which are not directly related to autoimmune reactivity, such as lupus podocytopathy. Moreover, not only glomerular diseases, but other severe forms of renal involvement, such as tubulo-interstitial nephritis or thrombotic microangiopathy may be detected by biopsy in lupus patients. Thus, an accurate definition of the nature and severity of renal involvement is mandatory to assess the possible risk of progression and to establish an appropriate treatment. The indications to repeat biopsy are more controversial. Some physicians recommend protocol biopsies to recognize the possible transformation from one class to another one, or to identify silent progression of renal disease, others feel that good clinical monitoring is sufficient to assess prognosis and to make therapeutic decisions. At any rate, although any decision should always be taken by considering the clinical conditions of the patient, there are no doubts that repeat renal biopsy may represent a useful tool in difficult cases to evaluate the response to therapy, to modulate the intensity of treatment, and to predict the long-term renal outcome both in quiescent lupus and in flares of activity.