Autoantibodies in the Diagnosis, Monitoring, and Treatment of Membranous Nephropathy

Clinicopathological characteristics and outcomes of PLA2R related idiopathic membranous nephropathy in patients with seronegative PLA2R antibodies

BACKGROUND

Idiopathic membranous nephropathy (IMN) with deposits of phospholipase A2 receptor (PLA2R) antigen in glomerular tissue (GAg+) but no circulating serum PLA2R antibody (SAb-) has been reported. However, little is known about the clinicopathological characteristics and prognosis of this subtype.

METHODS

A total of 74 IMN patients with GAg + identified by kidney biopsy were enrolled in this study. We categorized patients into two groups based on the presence or absence of serum PLA2R antibody. Data on clinical features, pathological features, and outcomes were collected. Kaplan-Meier analysis of complete remission (CR) and partial remission (PR) comparing SAb-/GAg + and SAb+/GAg + patients. Cox proportional hazards models was used to examine factors associated with CR and PR.

RESULTS

Among 74 IMN patients, 14 were SAb-/GAg+. Compared with SAb+/GAg + patients, SAb-/GAg + patients presented with higher levels of albumin, lower levels of cholesterol and low density lipoprotein cholesterol (all p < .01), but similar pathological manifestations of kidney biopsy. Multivariate logistic analyses indicated that low albumin (0.79 [95%CI: 0.66-0.95], p = .01) and high cholesterol (1.81 [95%CI: 1.02-3.19], p = .04) were correlated with seropositivity of PLA2R antibody. SAb-/GAg + patients exhibited a significantly higher probability of CR (p = .03) than patients who were SAb+/GAg+. However, no difference was found in the PR rate. Cox regression analyses showed that compared to SAb+/GAg + patients, SAb-/GAg + was more predictive of complete remission (4.28 [95%CI: 1.01-18.17], p = .04).

CONCLUSION

IMN with PLA2R staining on kidney biopsy but without serum PLA2R antibody has milder clinical manifestations and a better prognosis.

Membranous nephropathy: pathogenesis and treatments

Membranous nephropathy (MN), an autoimmune disease, can manifest at any age and is among the most common causes of nephrotic syndrome in adults. In 80% of cases, the specific etiology of MN remains unknown, while the remaining cases are linked to drug use or underlying conditions like systemic lupus erythematosus, hepatitis B virus, or malignancy. Although about one-third of patients may achieve spontaneous complete or partial remission with conservative management, another third face an elevated risk of disease progression, potentially leading to end-stage renal disease within 10 years. The identification of phospholipase A2 receptor as the primary target antigen in MN has brought about a significant shift in disease management and monitoring. This review explores recent advancements in the pathophysiology of MN, encompassing pathogenesis, clinical presentations, diagnostic criteria, treatment options, and prognosis, with a focus on emerging developments in pathogenesis and therapeutic strategies aimed at halting disease progression. By synthesizing the latest research findings and clinical insights, this review seeks to contribute to the ongoing efforts to enhance our understanding and management of this challenging autoimmune disorder.

Genetic association between membranous nephropathy and malignancies: a two-sample Mendelian randomisation study

BACKGROUND

Various studies have reported that individuals with membranous nephropathy (MN) exhibit an elevated susceptibility to cancers. However, a causal relationship has not been clearly established.

METHODS

We constructed a genetic score that predicts MN by utilizing genetic variants linked to this condition as instrumental variables. These genetic scores were then compared with lung, colon, breast, and prostate cancer risks by a two-sample Mendelian randomisation analysis involving the following methods: MR-Egger, weighted median, inverse variance weighted, simple mode, and weighted mode.

RESULTS

This study demonstrated a lack of empirical substantiation for a causal association between genetic variants in MN and the susceptibility to lung, colon, prostate, or breast cancer.

CONCLUSION

Overall, we did not detect a causal link between MN and lung, colon, breast, or prostate cancer. Hence, additional research is imperative to elucidate the underlying factors contributing to the heightened occurrence of tumour in patients with MN.

Clinicopathological and prognostic characteristics of idiopathic membranous nephropathy with dual antigen positivity

Background

Idiopathic membranous nephropathy (IMN) is the most common pathological type in adults with nephrotic syndrome. Many target antigens have been discovered. However, dual antigen-positive IMN patients are very rare, with only a few such cases being briefly described in various studies. There is no specific study on the clinicopathological and prognostic characteristics of dual antigen-positive IMN patients, and the disease characteristics of such patients remain unclear.

Methods

Immunohistochemical staining of PLA2R, THSD7A, and NELL-1 was conducted on kidney tissue samples obtained from patients diagnosed with IMN. Simultaneously, the presence of corresponding serum antibodies was determined. Patients exhibiting positivity for dual antigens were included in the study, identified either through tissue staining or serum antibody detection. We retrospectively collected their clinical, pathological, and follow-up data and measured their serum antibody levels at multiple time points. Additionally, the same type of dual antigen-positive IMN cases reported in the literature were reviewed to extract clinical, pathological, and prognostic information. We compared the data for all of the above dual antigen-positive and PLA2R single-positive IMN cases at our center.

Results

We identified 6 IMN patients with dual antigen positivity at our center, approximately 0.7% of whole MN series; the previous literature reports 43 IMN patients with dual antigen positivity, the proportion ranged from 0.2% to 2.8%. The IgG1 positivity rate in the renal tissue of the dual antigen-positive patients at our center was significantly lower than that of dual antigen-positive patients previously reported (16.7% vs. 100.0%, p=0.015), but there was no significant difference in clinical or prognostic aspects. Patients with dual antigen positivity reported at our center and in the literature were combined and compared with PLA2R single-positive IMN reported at our center. Compared with PLA2R single-positive IMN patients, dual antigen-positive IMN patients had a higher renal tissue IgG1 positivity rate (58.3% vs. 22.3%, p=0.016), and the time required to achieve remission was longer [13.5 (3.3,35.0) vs. 3.0 (1.0,8.0), p=0.052]. Overall, The changes in urine protein were consistent with the changes in serum PLA2R antibody levels in dual antigen-positive IMN patients.

Conclusions

For patients with primary membranous nephropathy who did not attain remission following prolonged treatment, multiple target antigen staining should still be actively performed, even with positivity for the PLA2R target antigen.

Varicella-zoster virus infection and primary membranous nephropathy: a Mendelian randomization study

Primary membranous nephropathy (MN) is a rare autoimmune cause of kidney failure. Observational studies have suggested some relationship between virus infection and primary MN, but the association remains unclear. The current study performed a two‑sample Mendelian randomization (MR) analysis to explore the causal association between varicella-zoster virus (VZV) infection (chickenpox and shingles) and primary MN using genome‑wide association studies (GWASs) summary statistics. The exposure datasets containing chickenpox and shingles were obtained from the GWASs conducted by the 23andMe cohort. And summary-level statistics for primary MN were used as the outcome dataset, comprising 2150 cases and 5829 controls from European Ancestry. The inverse variance weighted method was adopted as the main analysis. As a result, we found that both genetically determined chickenpox (odds ratio [95% confidential interval] = 3.61 [1.74-7.50], p = 5.59e-04) and shingles (p = 7.95e-03, odds ratio [95% confidential interval] = 2.49 [1.27-4.91]) were causally associated with an increased risk of developing primary MN. In conclusion, our MR findings provided novel genetic evidence supporting the causal effect of VZV infection on primary MN. Further studies are needed to elucidate the underlying mechanisms mediating the causal association.

THSD7A as a Promising Biomarker for Membranous Nephrosis

Membranous nephropathy (MN) is an autoimmune disease of the kidney glomerulus and one of the leading causes of nephrotic syndrome. The disease exhibits heterogeneous outcomes with approximately 30% of cases progressing to end-stage renal disease. Traditionally, the standard approach of diagnosing MN involves performing a kidney biopsy. Nevertheless, kidney biopsy is an invasive procedure that poses risks for the patient including bleeding and pain, and bears greater costs for the health system. The clinical management of MN has steadily advanced owing to the identification of autoantibodies to the phospholipase A2 receptor (PLA2R) in 2009 and thrombospondin domain-containing 7A (THSD7A) in 2014 on the podocyte surface. At present, serum anti-PLA2R antibody detection and glomerular PLA2R antigen staining have been used for clinical diagnosis and prognosis, but the related detection of THSD7A has not been widely used in clinical practice. Here, we summarized the emerging knowledge regarding the roles THSD7A plays in MN and its clinical implications as diagnostic, prognostic, and therapeutic response as well as Methods for detecting serum THSD7A antibodies.

Serum anti-phospholipase A2 receptor antibody in pathological diagnosis of type 2 diabetes mellitus patients with proteinuria

Patients with diabetes mellitus complicated with proteinuria can be diabetic nephropathy (DN), diabetic complicated with non-diabetic kidney disease (NDKD), or DN with NDKD. Among these membranous nephropathy accounted for a large proportion of DN with NDRD. At present, serum anti-phospholipase A2 receptor (PLA2R) antibody is widely used in the diagnosis and evaluation of therapy in idiopathic membranous nephropathy, our study aimed to investigate the diagnostic significance of anti-PLA2R antibody in type 2 diabetes mellitus (T2DM) patients with proteinuria, providing a method for patients with contraindications of kidney biopsy. Eighty-seven T2DM patients with proteinuria who went on kidney biopsy were divided into the DN group, idiopathic membranous nephropathy (IMN) group, and others group according to their pathological results. In our study, 52.87% and 28.74% of patients were found to have IMN and diabetic nephropathy respectively. The levels of anti-PLA2R antibody, total cholesterol, triglyceride, and estimated glomerular filtration rate (eGFR) were higher in the IMN group, while the prevalence of diabetic retinopathy (DR), systolic blood pressure (SBP) and HbA1c were higher in the DN group. For T2DM patients with proteinuria, anti-PLA2R antibody (AUC = 0.904, 95%CI 0.838-0.970) has a high diagnostic value for IMN. The duration of diabetes (OR = 0.798, P = 0.030), eGFR level (OR = 1.030, P = 0.024), and positive anti-PLA2R antibody (OR = 72.727, P < 0.001) favor the diagnosis of IMN, while DR (OR = 50.234, P < 0.001), SBP (OR = 1.041, P = 0.030), and negative anti-PLA2R antibody (OR = 0.008, P  = 0.001) is beneficial to the diagnosis of DN. Our study found that NDKD is not uncommon in patients with T2DM and proteinuria, and IMN was the main pathological type. Positive anti-PLA2R antibody has a strong accuracy in the diagnosis of IMN in patients with T2DM and proteinuria.

Membranous nephropathy with systemic light-chain amyloidosis of remission after rituximab therapy: A case report

BACKGROUND

About 70%-80% of patients with primary membranous nephropathy (MN) have phospholipase A2 receptor (PLA2R) in renal tissue. Systemic light-chain (AL) amyloidosis is the most common type of amyloidosis. MN complicated with amyloidosis is rare.

CASE SUMMARY

A 48-year-old Chinese male presented with nephrotic syndrome, positive serum PLA2R antibody, and positive serum and urine IgG-lambda type M-protein, with a normal ratio of serum-free light-chain level. The patient was diagnosed with MN accompanied by AL amyloidosis. He was treated with rituximab with glucocorticoids and CyBorD regimen of chemotherapy. After 21 mo of follow-up, the patient achieved complete remission regarding nephrotic syndrome without adverse effects of chemotherapy.

CONCLUSION

We report a case of PLA2R-related MN complicated with primary AL amyloidosis only with renal involvement and successfully treated with rituximab, glucocorticoids and chemotherapy.

Clinical covariates influencing clinical outcomes in primary membranous nephropathy

BACKGROUND

Primary membranous nephropathy (PMN) frequently causes nephrotic syndrome and declining kidney function. Disease progression is likely modulated by patient-specific and therapy-associated factors awaiting characterization. These cofactors may facilitate identification of risk groups and could result in more individualized therapy recommendations.

METHODS

In this single-center retrospective observational study, we analyze the effect of patient-specific and therapy-associated covariates on proteinuria, hypoalbuminemia, and estimated glomerular filtration rate (eGFR) in 74 patients diagnosed with antibody positive PMN and nephrotic-range proteinuria (urine-protein-creatinine-ratio [UPCR] ≥ 3.5 g/g), treated at the University of Freiburg Medical Center between January 2000 - November 2022. The primary endpoint was defined as time to proteinuria / serum-albumin response (UPCR ≤ 0.5 g/g or serum-albumin ≥ 3.5 g/dl), the secondary endpoint as time to permanent eGFR decline (≥ 40% relative to baseline).

RESULTS

The primary endpoint was reached after 167 days. The secondary endpoint was reached after 2413 days. Multivariate time-to-event analyses showed significantly faster proteinuria / serum-albumin response for higher serum-albumin levels (HR 2.7 [95% CI: 1.5 - 4.8]) and cyclophosphamide treatment (HR 3.6 [95% CI: 1.3 - 10.3]). eGFR decline was significantly faster in subjects with old age at baseline (HR 1.04 [95% CI: 1 - 1.1]).

CONCLUSION

High serum-albumin levels, and treatment with cyclophosphamide are associated with faster proteinuria reduction and/or serum-albumin normalization. Old age constitutes a risk factor for eGFR decline in subjects with PMN.

Liquid biopsy for non-invasive monitoring of patients with kidney transplants

The current tools for diagnosing and monitoring native kidney diseases as well as allograft rejection in transplant patients are suboptimal. Creatinine and proteinuria are non-specific and poorly sensitive markers of injury. Tissue biopsies are invasive and carry potential complications. In this article, we overview the different techniques of liquid biopsy and discuss their potential to improve patients' kidney health. Several diagnostic, predictive, and prognostic biomarkers have been identified with the ability to detect and monitor the activity of native kidney diseases as well as early and chronic allograft rejection, such as donor-derived cell-free DNA, exosomes, messenger RNA/microsomal RNA, proteomics, and so on. While the results are encouraging, additional research is still needed as no biomarker appears to be perfect for a routine application in clinical practice. Despite promising advancements in biomarkers, the most important issue is the lack of standardized pre-analytical criteria. Large validation studies and uniformed standard operating procedures are required to move the findings from bench to bedside. Establishing consortia such as the Liquid Biopsy Consortium for Kidney Diseases can help expedite the research process, allow large studies to establish standardized procedures, and improve the management and outcomes of kidney diseases and of kidney transplant recipients.

Immunosuppressive Agent Options for Primary Nephrotic Syndrome: A Review of Network Meta-Analyses and Cost-Effectiveness Analysis

Therapeutic options with immunosuppressive agents for glomerular diseases have widened with refinements to the Kidney Disease Improving Global Outcomes (KDIGO) guidelines from 2012 to 2021. However, international guidelines do not necessarily match the reality in each country. Expensive therapies such as rituximab and calcineurin inhibitors are sometimes inaccessible to patients with refractory nephrotic syndrome due to cost or regulations. Under the Japanese medical insurance system, rituximab is accessible but still limited to steroid-dependent patients who developed idiopathic nephrotic syndrome in childhood. Based on international KDIGO guidelines and other national guidelines, possible applications of immunosuppressive agents for nephrotic syndrome are comprehensively examined in this review. While rituximab has become the mainstay of immunosuppressive therapy for nephrotic syndrome, clinical trials have indicated that options such as cyclophosphamide, calcineurin inhibitors, and mycophenolate mofetil would be preferable. Given the rising number of patients with nephrotic syndrome worldwide, KDIGO guidelines mention the need for further consideration of cost-effectiveness. If the new option of rituximab is to be the first choice in combination with steroids for nephrotic syndrome, its cost-effectiveness should also be verified. Among the few studies examining the cost-effectiveness of treatments for nephrotic syndrome, administration of rituximab to young adults has been shown to be cost-beneficial, at least in Japan. However, further large-scale studies involving multiple facilities are needed to verify such findings. Network meta-analyses have concluded that the efficacy of rituximab remains controversial and confirmation through high-quality studies of large cohorts is needed. To this end, the mechanisms of action underlying immunosuppressive agents, both old and new, need to be understood and experience must be accumulated to evaluate possible effects and side effects.

Preliminary study on the efficacy of rituximab in the treatment of idiopathic membranous nephropathy: A single-centre experience

OBJECTIVE

To investigate the efficacy of rituximab in the treatment of idiopathic membranous nephropathy (IMN).

METHODS

A total of 77 patients with IMN diagnosed in both our hospital and other hospitals were included in this study; the patients were divided into two groups: a treatment-naïve group (n = 19) and a refractory/relapsed group (n = 58). The clinical data of the patients, including urine examination, blood test, safety evaluation and efficacy evaluation results, were analysed retrospectively. The changes in clinical biochemical indexes and adverse reactions were compared between the two groups before and after treatment, and the clinical efficacy of rituximab (RTX) in the treatment of primary IMN and refractory recurrent membranous nephropathy was evaluated.

RESULTS

Of the 77 patients included in this study, the average age was 48 years, and there was a male-to-female ratio of 61:16. There were 19 cases in the initial treatment group and 58 cases in the refractory/relapse group. The 24-hour urine protein quantification, cholesterol, B cell count and M-type phospholipase A2 receptor (PLA2R) results in the 77 patients with IMN after treatment were all lower than those before treatment, and the differences were statistically significant (P < 0.05). Serum albumin was higher than before treatment, and the difference was statistically significant (P < 0.05). The total remission rate in the initial and refractory/relapsed treatment groups was 84.21% and 82.76%, respectively. There was no statistical difference in the total remission rate between the two groups (P > 0.05). During treatment, nine patients (11.69%) experienced infusion-related adverse reactions, which were relieved rapidly after symptomatic treatment. The anti-PLA2R antibody titre of the refractory/relapsed group was significantly negatively correlated with serum creatinine (r = -0.187, P = 0.045) and significantly correlated with 24-hour urine protein (r = -0.490, P < 0.001). There was a positive correlation and a significant negative correlation with serum albumin (r = -0.558, P < 0.001).

CONCLUSIONS

Regardless of whether RTX is used as an initial therapy or refractory/relapsed membranous nephropathy, most patients with IMN have complete or partial remission after RTX treatment, with mild adverse reactions.

Clinicopathological features and prognosis of idiopathic membranous nephropathy with thyroid dysfunction

BACKGROUND

Thyroid dysfunction is common in patients with kidney disease. However, the relationship between thyroid dysfunction and idiopathic membranous nephropathy (IMN) remains unclear. This retrospective study aimed to investigate the clinicopathological characteristics and prognosis of patients with IMN and thyroid dysfunction compared to patients with IMN and without thyroid dysfunction.

METHODS

A total of 1052 patients with IMN diagnosed by renal biopsy were enrolled in this study, including 736 (70%) with normal thyroid function and 316 (30%) with abnormal thyroid function. We analyzed the clinicopathological features and prognostic data between the two groups, using propensity score matching (PSM) to reduce the bias. Logistic regression analysis was performed to investigate the risk factors for IMN combined with thyroid dysfunction. Kaplan-Meier curves and Cox regression analysis were used to evaluate the association between thyroid dysfunction and IMN.

RESULTS

Patients with IMN and thyroid dysfunction exhibited more severe clinical features. Female sex, lower albumin level, higher D-dimer level, severe proteinuria, and decreased estimated glomerular filtration rate were predictors of thyroid dysfunction in patients with IMN. After PSM, 282 pairs were successfully matched. Results from the Kaplan-Meier curves indicated that the thyroid dysfunction group had a lower complete remission rate (P = 0.044), higher relapse rate (P < 0.001), and lower renal survival rate (P = 0.004). The multivariate Cox regression analysis revealed that thyroid dysfunction was an independent risk factor for complete remission [hazard ratio (HR) = 0.810, P = 0.045], relapse (HR = 1.721, P = 0.001), and composite endpoint event (HR = 2.113, P = 0.014) in IMN.

CONCLUSIONS

Thyroid dysfunction is relatively common in patients with IMN, and the clinical indicators are more severe in these patients. Thyroid dysfunction is an independent risk factor for poor prognosis in patients with IMN. More attention should be paid to thyroid function in patients with IMN.

B7-1 mediates podocyte injury and glomerulosclerosis through communication with Hsp90ab1-LRP5-β-catenin pathway

Podocyte injury is a hallmark of glomerular diseases; however, the underlying mechanisms remain unclear. B7-1 is increased in injured podocytes, but its intrinsic role is controversial. The clinical data here revealed the intimate correlation of urinary B7-1 with severity of glomerular injury. Through transcriptomic and biological assays in B7-1 transgenic and adriamycin nephropathy models, we identified B7-1 is a key mediator in podocyte injury and glomerulosclerosis through a series of signal transmission to β-catenin. Using LC-MS/MS, Hsp90ab1, a conserved molecular chaperone, was distinguished to be an anchor for transmitting signals from B7-1 to β-catenin. Molecular docking and subsequent mutant analysis further identified the residue K69 in the N terminal domain of Hsp90ab1 was the key binding site for B7-1 to activate LRP5/β-catenin pathway. The interaction and biological functions of B7-1-Hsp90ab1-LRP5 complex were further demonstrated in vitro and in vivo. We also found B7-1 is a novel downstream target of β-catenin. Our results indicate an intercrossed network of B7-1, which collectively induces podocyte injury and glomerulosclerosis. Our study provides an important clue to improve the therapeutic strategies to target B7-1.

Hypercholesterolemia Correlates With Glomerular Phospholipase A2 Receptor Deposit and Serum Anti-Phospholipase A2 Receptor Antibody and Predicts Proteinuria Outcome in Idiopathic Membranous Nephropathy

Background

The anti-phospholipase A2 receptor (PLA2R) antibody is a non-invasive diagnostic tool and prognosis predictor of idiopathic membranous nephropathy (IMN). Baseline hypercholesterolemia independently predicts proteinuria outcomes in IMN patients. Thus, we investigated whether hyperlipidemia is correlated with anti-PLA2R and pathological indicators.

Methods

A total of 495 IMN patients identified by kidney biopsy in Wuhan Tongji Hospital, China, from January 2016 through December 2020 were enrolled in this study. Data on clinical features, pathology findings, and outcomes were collected.

Results

Total cholesterol (TC), non-high-density lipoprotein cholesterol (non-HDL-C), low-density lipoprotein cholesterol (LDL-C), and triglyceride (TG) were positively related to proteinuria, indicating damage to the renal glomerulus [Spearman’s rank correlation coefficient = 0.432, 0.462, 0.315, and 0.289, respectively, P < 0.001 for all]. In univariate logistic regression, low HDL-C [odds ratio (OR): 0.856; 95% CI: 0.778–0.939; P = 0.001] and high TG [OR: 1.025; 95% CI: 1.006–1.044; P = 0.011] were correlated with tubular atrophy, suggesting lesions on tubules. Increased TC [adjusted OR: 1.285; 95% CI: 1.119–1.475; P < 0.001], non-HDL-C [adjusted OR: 1.284; 95% CI: 1.113–1.482; P = 0.001], and LDL-C [adjusted OR: 1.178; 95% CI: 1.009–1.376; P = 0.039] independently predicted glomerular PLA2R deposit; similar results were observed for lipids in predicting the seropositivity of anti-PLA2R antibodies. After treatment, increased HDL-C [adjusted hazard ratio (HR): 1.764; 95% CI: 1.241–2.507; P = 0.002] and decreased non-HDL-C [adjusted HR: 0.884; 95% CI: 0.795–0.983; P = 0.022] independently predicted proteinuria remission.

Conclusion

Hypercholesterolemia is a potentially useful biomarker for disease severity, serum anti-PLA2R antibody, glomerular PLA2R deposit, and proteinuria outcome of IMN.

Recent Advances in Clinical Diagnosis and Pharmacotherapy Options of Membranous Nephropathy

Membranous nephropathy (MN) is the most common cause of nephrotic syndrome among adults, which is the leading glomerular disease that recurs after kidney transplantation. Treatment for MN remained controversial and challenging, partly owing to absence of sensitive and specific biomarkers and effective therapy for prediction and diagnosis of disease activity. MN starts with the formation and deposition of circulating immune complexes on the outer area in the glomerular basement membrane, leading to complement activation. The identification of autoantibodies against the phospholipase A₂ receptor (PLA₂R) and thrombospondin type-1 domain-containing protein 7A (THSD7A) antigens illuminated a distinct pathophysiological rationale for MN treatments. Nowadays, detection of serum anti-PLA₂R antibodies and deposited glomerular PLA₂R antigen can be routinely applied to MN. Anti-PLA₂R antibodies exhibited much high specificity and sensitivity. Measurement of PLA₂R in immune complex deposition allows for the diagnosis of PLA₂R-associated MN in patients with renal biopsies. In the review, we critically summarized newer diagnosis biomarkers including PLA₂R and THSD7A tests and novel promising therapies by using traditional Chinese medicines such as Astragalus membranaceus, Tripterygium wilfordii, and Astragaloside IV for the treatment of MN patients. We also described unresolved questions and future challenges to reveal the diagnosis and treatments of MN. These unprecedented breakthroughs were quickly translated to clinical diagnosis and management. Considerable advances of detection methods played a critical role in diagnosis and monitoring of treatment.

Secretory expression and purification of recombinant PLA2R epitopes for the detection of anti-PLA2R autoantibody in serum

M-type phospholipase A2 receptor (PLA2R) is a significant biomarker contributing to the clinical diagnosis of idiopathic membranous nephropathy (IMN).

Case Report: THSD7A-Positive Membranous Nephropathy Caused by Tislelizumab in a Lung Cancer Patient

Immune checkpoint inhibitors (ICIs) became the standard treatment for many different kinds of cancers and can result in a variety of immune-related adverse events (irAEs). IrAEs of kidney are uncommon and consists of different pathology types. Among the different types, membranous nephropathy (MN) is rare and have not been well-described. Since MN can also be associated with malignancies, differential diagnosis in patients receiving ICIs who develop MN can be very difficult. We present the case of a 74-year-old man with metastatic non-small cell lung cancer who developed MN after ICIs therapy. The patient tested positive for thrombospondin type-1 domain-containing 7A antibodies (THSD7A) when diagnosed with MN. Supplementary examinations revealed the predisposing antigen in the primary tumor and present of the antibody after immunotherapy, which corresponded to the patient’s clinical course of nephropathy. Treatment consisting of systemic glucocorticoids and rituximab resulted in a good clinical response, and the THSD7A antibodies were no longer detected. In this case, we first discuss the potential mechanism of immunotherapy related MN, in which the activation of humoral immunity may play an important role.