Nephrotic syndrome associated with solid malignancies: a systematic review

BACKGROUND

Nephrotic syndrome (NS) can occur as a paraneoplastic disorder in association with various types of carcinoma. However, paraneoplastic nephrotic syndrome (PNS) is often misdiagnosed as idiopathic nephrotic syndrome or as an adverse effect of oncology treatment, leading to delayed diagnosis and suboptimal treatment. The characteristics of NS associated with solid malignancies are not yet elucidated. We systematically summarized the clinical data for 128 cases of NS combined with solid malignancies with the aim of informing the clinical management of PNS.

METHODS

We searched the PubMed database for articles published from the date of inception through to October 2023 using the following keywords: "cancer" or "malignant neoplasms" or "neoplasia" or "tumors" and "nephrotic syndrome", "nephrotic" or "syndrome, nephrotic". All data were extracted from case reports and case series, and the extraction included a method for identifying individual-level patient data.

RESULTS

A literature search yielded 105 cases of PNS and 23 of NS induced by cancer therapy. The median age at diagnosis was 60 years, with a male to female ratio of 1.8:1. In patients with PNS, manifestations of NS occurred before, concomitantly with, or after diagnosis of the tumor (in 36%, 30%, and 34% of cases, respectively). Membranous nephropathy (49%) was the most prevalent renal pathology and found particularly in patients with lung, colorectal, or breast carcinoma. Regardless of whether treatment was for cancer alone or in combination with NS, the likelihood of remission was high.

CONCLUSION

The pathological type of NS may be associated with specific malignancies in patients with PNS. Prompt identification of PNS coupled with suitable therapeutic intervention has a significant impact on the outcome for patients.

Usefulness of Dapagliflozin for Nephrotic Syndrome Secondary to Diabetic Kidney Disease

An 81-year-old woman with a medical history of type 2 diabetes mellitus and diabetic nephropathy was admitted with a diagnosis of multiple cerebellar infarctions. Proteinuria and leg edema were observed on the day after admission and diagnosed as nephrotic syndrome. Furosemide and spironolactone were started but showed no diuretic effect, and the renal function deteriorated. These agents were then replaced with dapagliflozin, which resulted in a positive diuretic effect and subsequent improvement of hypoalbuminemia and renal dysfunction. This case report demonstrates the utility of dapagliflozin for nephrotic syndrome to achieve a positive diuretic effect and improve hypoalbuminemia without deteriorating the renal function.

Nephrotic syndrome associated with metastatic melanoma: a case report

Nephrotic syndrome (NS) may occur after or concomitantly with malignancy. The use of immunosuppressive approaches in patients with cancer and NS is controversial, especially when the association between the pathologies is unclear. The aim of this study was to report the case of a patient with metastatic melanoma who developed NS and to examine the association between NS and neoplasia. A 56-year-old woman diagnosed with right hallux melanoma, removed by marginal resection with no sign of metastasis, developed NS after 6 months without the detection of another associated disease. The histological diagnosis was focal and segmental glomerulosclerosis (FSGS). The patient was older than most patients with FSGS and was treated with immunosuppressive agents (prednisone and cyclosporine) concomitantly with melanoma treatment. Nephrotic syndrome was the first manifestation of metastatic melanoma recurrence in this patient. Proteinuria was controlled adequately after immunosuppression and melanoma treatment. Although NS has been associated with cancer, laboratory and histological markers correlating it with melanoma are needed.

Prevalence of pulmonary thromboembolism in nephrotic syndrome patients: A systematic review and meta-analysis

This study was aimed to assess the prevalence of pulmonary thromboembolism in patients with nephrotic syndrome. An electronic search was conducted through nine electronic databases for selection of relevant articles reporting the prevalence of pulmonary thromboembolism in patients with nephrotic syndrome. National Institute of Health was used to assess the quality of each study. Meta-analysis was used to pool the results. Of total 2267 reports screened, we finally included 11 studies including five retrospective cohorts, four prospective cohorts, and two case series studies. Out of these, ten articles were eligible for meta-analysis. The overall prevalence was 7.93% with 95% CI of 4.27 to 14.73. However, a significant heterogeneity (P < 0.001) was observed with I2= 96% and τ2= 0.899. Moreover, Egger's regression test showed a significant risk of bias (P = 0.006). Patients with nephrotic syndrome are prone to pulmonary embolism, therefore early management is critical to decreasing mortality burden.

Remission of nephrotic syndrome after surgical intervention for bronchogenic carcinoma: the 10-year follow-up of a patient with membranous nephropathy

Nephrotic syndrome (NS) is a pivotal manifestation of glomerular injury associated with various types of neoplasms. It may either precede or act as the presenting feature of the disease, whereas membranous nephropathy (MN) is a major phenotype of paraneoplastic glomerulopathies. However, there is a lack of information regarding the remission from paraneoplastic NS due to MN in patients who achieve favorable long-term survival after the successful removal of malignant tissue. We, herein, describe a case of biopsy-proven MN in a 65-year-old male patient with bronchogenic carcinoma, which was found during the systemic workup for concurrent NS. He was successfully treated with thoracoscopic left lower lobectomy and achieved a complete remission from NS at approximately 10 months after radical surgery. In 10 years of follow-up, there has been no recurrence of the pulmonary cancer and the patient is doing well with no relapse of NS, despite having never received treatment with any type of immunomodulating agent. Several concerns, including diagnostic management and therapeutic strategies for paraneoplastic NS, are discussed.

Glomerular diseases and cancer: evaluation of underlying malignancy

Onconephrology is an emerging medical subspecialty focused on the numerous interconnections between cancer and kidney diseases. Patient with malignancies commonly experience kidney problems including acute kidney injury, tumor lysis syndrome, fluid and electrolyte disorders and chronic kidney disease, often as a consequence of the anti-cancer treatment. Conversely, a number of glomerulopathies, tubulopathies and vascular renal diseases can early signal the presence of an underlying cancer. Furthermore, the administration of immunosuppressive drugs, especially cytotoxic drugs and calcineurin inhibitors, may strongly impair the immune response increasing the risk of cancer. The objective of this review article is to: (i) discuss paraneoplastic glomerular disease, (ii) review cancer as an adverse effect of immunosuppressive agents used to treat glomerulopathies, and (iii) in the absence of international approved guidelines, propose a screening program based on expert opinion aimed at guiding nephrologists to early detect malignancies during their clinical practice.

Primary Nephrotic Syndrome in Adults as a Risk Factor for Pulmonary Embolism: An Up-to-Date Review of the Literature

Patients with nephrotic syndrome are at an increased risk for thrombotic events; deep venous thrombosis, renal vein thrombosis, and pulmonary embolism are quite common in patients with nephrotic syndrome. It is important to note that nephrotic syndrome secondary to membranous nephropathy may impose a greater thrombotic risk for unclear reasons. Increased platelet activation, enhanced red blood cell aggregation, and an imbalance between procoagulant and anticoagulant factors are thought to underlie the excessive thrombotic risk in patients with nephrotic syndrome. The current scientific literature suggests that patients with low serum albumin levels and membranous nephropathy may benefit from primary prophylactic anticoagulation. A thorough approach which includes accounting for all additional thrombotic risk factors is, therefore, essential. Patient counseling regarding the pros and cons of anticoagulation is of paramount importance. Future prospective randomized studies should address the question regarding the utility of primary thromboprophylaxis in patients with nephrotic syndrome.

Prevalence of cancer in membranous nephropathy: a systematic review and meta-analysis of observational studies

BACKGROUND

The association between membranous nephropathy (MN) and cancer has been well documented. However, the true prevalence and characteristics of cancer associated with MN have not been well described.

METHODS

A systematic review and meta-analysis of cohort studies was conducted to summarize the prevalence of cancer-associated MN as well as patient characteristics and types of cancer in this population. We used a random-effects meta-analysis model to estimate the prevalence of cancer.

RESULTS

We included 6 studies (n = 785). The estimated prevalence of cancer was 10.0% (95% CI, 6.1-14.6). The mean age of MN patients with cancer was 67 ± 7 years. The diagnosis of cancer preceded the diagnosis of MN in 20 ± 6.8%. Lung cancer was the most common type of tumor, accounting for 22 cases (26%), followed by prostate cancer (13 cases, 15%), hematologic malignancies (12 cases, 14%), colorectal cancer (9 cases, 11%), breast cancer (6 cases, 7%), and stomach and esophageal cancer (5 cases, 6%).

CONCLUSION

The estimated prevalence of cancer in patients with MN is 10% (95% CI, 6.1-14.6). The vast majority of tumors associated with MN are lung and prostate cancer. Hematologic malignancies should also be considered as one of the potential cancers associated with MN. Our study was based on a largely Caucasian population; therefore, the findings might not be applicable to other populations.

Membranous glomerulonephritis with crescents

PURPOSE

The coexistence of membranous glomerulonephritis (MGN) and necrotizing and crescentic glomerulonephritis (NCGN) is an unusual finding in a renal biopsy except in lupus nephritis. Little is known about whether these lesions are causally related in any clinical setting.

METHODS

We reviewed the pathology, presentation, and clinical course of 13 non-lupus patients with combined MGN and NCGN in native kidney biopsies (nine females, four males; median age 69 years), with particular attention to evidence of secondary MGN. Additional IgG subclass and phospholipase A2 receptor (PLA2R) immunofluorescence studies were conducted in seven cases.

RESULTS

Eight biopsies were pauci-immune other than the capillary wall deposits of MGN; one patient had a non-lupus immune complex disease, and four had mesangial deposits, including one with rare subendothelial deposits. None had anti-glomerular basement membrane disease. IgG4 was dominant or codominant in the capillary wall deposits in three cases and virtually absent in four; PLA2R was positive in two cases, and negative in five. Seven patients were judged to have secondary MGN, including five of eight ANCA+ patients. Twelve patients were treated with combinations of steroids, cyclophosphamide, rituximab, followed by durable response in seven and relentless progression to end stage renal disease in four.

CONCLUSIONS

Secondary MGN occurs with higher frequency in ANCA-positive NCGN than in the general MGN population. A causal relationship between MGN and NCGN was not established in any patient, but circumstances suggest a common cause in several, including immune complex disease, drug reaction and paraneoplastic syndrome.

Determination of primary versus secondary membranous glomerulopathy utilizing phospholipase A2 receptor staining in renal biopsies

Autoantibody formation directed against phospholipase A2 receptor (PLA2R)1 is the underlying etiology in most cases of primary membranous glomerulopathy. This new understanding of the pathogenesis of primary membranous is in the process of transforming the way the disease is diagnosed. We validated an indirect immunofluorescence assay to examine PLA2R1 in renal biopsies utilizing a commercially available antibody and standard indirect immunofluorescence. Using this assay, we examined a total of 165 cases of membranous glomerulopathy including 85 primary and 80 secondary. We found tissue staining for PLA2R1 to have a sensitivity of 75% (95% CI 65-84%) and a specificity of 83% (95% CI 72-90%) for primary membranous glomerulopathy. Hepatitis C virus was the secondary etiology with the most number of cases staining positive for PLA2R1 (7/11, 64%) followed by sarcoidosis (3/4, 75%) and neoplasm (3/12, 25%). Autoimmune etiologies showed rare PLA2R1-positive staining (1/46, 2%). All cases of secondary membranous glomerulopathy with positive PLA2R1 showed IgG4-predominant staining, which is typically associated with primary membranous glomerulopathy. This IgG4 predominance raises the possibility that these cases are more pathogenically related to primary membranous glomerulopathy than secondary. We present the largest case series to date examining PLA2R1 involvement in membranous glomerulopathy utilizing a technique that is readily adoptable by most renal pathology laboratories.