Pathogenesis, diagnosis and management of paraneoplastic glomerulonephritis

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.

Paraneoplastic Glomerular Diseases

Paraneoplastic glomerular disease (PGD) develops from tumor cell products, leading to renal dysfunction. Unlike direct tumor effects, PGD illustrates the complex association between cancer and diverse clinical presentations and outcomes. Initially detected in a Hodgkin's disease patient, current research has defined diagnostic criteria based on PGD symptoms and cancer progression. PGDs, although rare (found in <1% of adult cancer patients with overt renal manifestations), are crucial, as they can signal cancer onset and frequently resist standard glomerulonephritis treatments. The emerging field of onconephrology studies this relationship between kidney disorders and cancers. The exact cause of many PGD cases remains unknown. This review examines PGDs, their clinicopathological features, related cancers, and mechanisms, emphasizing the need for early diagnosis and tailored treatment for kidney disease and linked cancer.

Successful post-incomplete resection management of gastrointestinal stromal tumor using imatinib based on adenosine triphosphate-based tumor sensitivity assay in a dog

Gastrointestinal stromal tumors arising from gastric cardia are uncommon in dogs. A few studies have shown the effectiveness of tyrosine kinase inhibitors in the treatment of canine gastrointestinal stromal tumors, but no standardized protocols are currently available. An 11-year-old spayed female Maltese dog was diagnosed with a gastrointestinal stromal tumor using histopathological and immunohistochemical analyses. An adenosine triphosphate-based tumor chemosensitivity assay revealed that imatinib at lower concentrations had a stronger inhibitory effect than toceranib. Based on the results of the assay, the dog was treated with imatinib after surgery. After 28 mo of therapy, there was no recurrence of the tumor. Key clinical message: Adenosine triphosphate-based tumor chemosensitivity assays may help clinicians to select appropriate postoperative chemotherapeutic drugs for incompletely resected gastrointestinal stromal tumors in dogs.

A Child With Concomitant Neuroblastoma and IgA Nephropathy: A Case Report and Literature Review

Concurrent malignancy and IgA nephropathy are rare. Despite the lack of solid experimental evidence, there are theoretical hypotheses of pathophysiology for the development of glomerular damage in cancer patients, like aberrant immune activities. Here, we describe a nine-year-old child who was admitted due to nephrotic syndrome. Abdominal imaging examination accidentally revealed a retroperitoneal tumor, and surgical resection was performed with a pathological diagnosis of neuroblastoma. However, complete removal of the tumor had no impact on the clinical manifestation of nephrotic syndrome, like proteinuria. The use of corticosteroids alone only led to a partial resolution of proteinuria, and resistance developed after one month of treatment. A further kidney biopsy was performed, which suggested IgA nephropathy. Clinical remission of IgA nephropathy was achieved after standard combination treatment of corticosteroids and mycophenolate mofetil for 10 months. This study represented the first case report of neuroblastoma associated with IgA nephropathy. We postulated that IgA nephropathy pathogenesis might be associated with neuroblastoma, though a coincidence of these two conditions cannot be fully excluded. Standard treatment for IgA nephropathy is applicable for patients with concomitant cancer.

Chapter 1: Evaluation of kidney function in patients undergoing anticancer drug therapy, from clinical practice guidelines for the management of kidney injury during anticancer drug therapy 2022

The prevalence of CKD may be higher in patients with cancer than in those without due to the addition of cancer-specific risk factors to those already present for CKD. In this review, we describe the evaluation of kidney function in patients undergoing anticancer drug therapy. When anticancer drug therapy is administered, kidney function is evaluated to (1) set the dose of renally excretable drugs, (2) detect kidney disease associated with the cancer and its treatment, and (3) obtain baseline values for long-term monitoring. Owing to some requirements for use in clinical practice, a GFR estimation method such as the Cockcroft-Gault, MDRD, CKD-EPI, and the Japanese Society of Nephrology's GFR estimation formula has been developed that is simple, inexpensive, and provides rapid results. However, an important clinical question is whether they can be used as a method of GFR evaluation in patients with cancer. When designing a drug dosing regimen in consideration of kidney function, it is important to make a comprehensive judgment, recognizing that there are limitations regardless of which estimation formula is used or if GFR is directly measured. Although CTCAEs are commonly used as criteria for evaluating kidney disease-related adverse events that occur during anticancer drug therapy, a specialized approach using KDIGO criteria or other criteria is required when nephrologists intervene in treatment. Each drug is associated with the different disorders related to the kidney. And various risk factors for kidney disease associated with each anticancer drug therapy.

Paraneoplastic Glomerulonephropathy Associated With Renal Cell Carcinoma: A Descriptive Analysis of Published Reports

Paraneoplastic glomerulonephropathy (PGN) is a rare paraneoplastic syndrome that is associated with a variety of malignancies. Patients with renal cell carcinomas (RCCs) often develop paraneoplastic syndromes including PGN. To date, objective diagnostic criteria of PGN are not defined. As a result, the true occurrences are unknown. Many RCC patients develop renal insufficiency in the course of their disease, and diagnosis of PGN in this population is challenging and often delayed, which may lead to significant morbidity and mortality. Here, we provide a descriptive analysis of the clinical presentation, treatment, and outcomes of 35 published patient cases of PGN associated with RCCs over the past four decades in PubMed-indexed journals. Most patients with PGN were male (77%), over 60 years of age (60%), and diagnosed with PGN prior to or concurrent with their diagnosis of RCC (20% prior, 71% concurrent). Membranous nephropathy (34%) was the most common pathologic subtype. Among the patients with localized RCCs, 16 (67%) of 24 patients had improvement in PGN compared to 4 (36%) of 11 patients with metastatic RCCs. All 24 patients with localized RCCs underwent nephrectomy, but patients who were treated with nephrectomy with immunosuppression (7/9, 78%) had a better outcome than patients who were treated with nephrectomy alone (9/15, 60%). Among the patients with metastatic RCCs, patients who were treated with systemic therapy along with immunosuppression (4/5, 80%) had a better outcome than those who were treated with systemic therapy, nephrectomy, or immunosuppression alone (1/6, 17%). Our analysis demonstrates the importance of cancer-specific therapy; nephrectomy in localized disease and systemic therapy in metastatic disease, along with immunosuppression, was the effective management of PGN. Immunosuppression alone is not adequate in most patients. This is distinct from other glomerulonephropathy and warrants further study.

Role of synthetical amynoquinone ethyl 2-(1,4-dioxo-1,4-dihydronaphthalen-2-ylamino) acetate in inhibition of Ehrlich's tumor

Quinones are naturally or synthetically occurring secondary metabolites that have various bio-dynamics, highlighting their antitumor potential. This has been explored through their selective cytotoxicity, and studies in medicinal chemistry about the relation between biological activity versus chemical structure may lead to the solution of the toxicity problems associated with quinones. In this context, the antitumor effect of a synthetic naphthoquinone, named Ethyl 2-(1,4-Dioxo-1,4-Dihydronaphthalen-2-Ylamino) Acetate, was tested using mice transplanted with Ehrlich ascitic tumor as an experimental model. The acute toxicity test was performed using 30 mice that received the aminoquinone at doses of 100, 200, 300, and 600 mg/kg. After evaluation of the clinical findings in the spontaneous activity tests, the LD50 calculation for the test substance showed low levels of toxicity at doses lower than 244.11 ± 23.29 mg/kg. Thus, three experimental groups were established, where animals transplanted with tumor cells received NaCl vehicle solution (control, n = 6), and the others were treated with 71.7 mg/kg of Methotrexate (n = 6) or 20 mg/kg of Aminoquinone (n = 6). All administrations were intraperitoneal, in a single dose. Three days after the implantation of the tumor cells the animals were weighed daily and evaluated for tumor biometry and development. The treatments occurred five days after the implantation of the tumor cells and were extended for 7 more days. At the end of the 12-day experimental period, all animals were euthanized for biochemical and histopathological analyses of the tumors and vital organs. The spontaneous activity test showed that the amount of responses associated with the nervous system tends to increase with the increase in dosage, highlighting the excitatory effect on the central nervous system in almost all dosages employed, followed by depressant activities on this system. There was a significant tumor reduction, both in animals treated with methotrexate (71.7 %) and in those treated with aminoquinone (91.6 %) in the control group. There was no significant difference in tumor volume between the animals treated with aminoquinone or methotrexate. The histopathological analysis revealed that in both treatments there were fewer mitoses in the tumor mass compared to the control group. However, there was apparent toxicity to the liver, heart, and left kidney in the treatment with methotrexate compared to aminoquinone. The significant capacity for tumor reduction presented by aminoquinone allows pointing it as a promising alternative for the development of a more efficient drug to control tumor development, being necessary for the development of new studies to deepen the knowledge about its mechanisms of action.

[Glomerulopathy in kidney neoplasms: frequency of occurrence, structure of morbidity]

BACKGROUND

Malignant neoplasms of the kidneys are among the 10 most common oncological diseases in Russia, in which various kidney lesions can occur, including glomerulopathy. Glomerular pathology can be an independent nosology, a manifestation of paraneoplastic syndrome or metabolic disturbances.

OBJECTIVE

Evaluation of the incidence and structure of glomerulopathies in patients with kidney neoplasms.

MATERIAL AND METHODS

We analyzed 141 samples with a tumor obtained during nephrectomy. To diagnose glomerular pathology, a fragment of the kidney parenchyma was examined at a distance of at least 4 cm from the tumor border. Histological slides were stained with hematoxylin and eosin, methenamine silver, trichrome Masson, Congo red, PAS reaction was performed. Immunofluorescent microscopy was performed with antibodies to IgA, IgG, IgM, C3c, C1q, Kappa light chain and Lambda light chain. Samples for electron microscopy were contrasted with a solution of 0.1% lead citrate.

RESULTS

Malignant neoplasms were diagnosed in 130 (92.2%) patients, benign ones - in 11 (7.8%) patients. In 59 patients with kidney tumors, glomerulopathies were detected, which amounted to 41.8%. All cases of glomerulopathies were diagnosed in combination with carcinomas of the kidneys and renal pelvis. Among 59 cases of glomerulopathy, diabetic nephropathy was diagnosed in 44 (74.6%) cases, IgA nephropathy - in 7 (11.9%) cases, membranous nephropathy - in 1 (1.6%), minimal change disease - in 2 (3.4%), focal segmental glomerulosclerosis - in 5 (8.5%).

CONCLUSION

The study demonstrates a high incidence of glomerulopathies in patients with malignant kidney tumors. The performed work emphasizes the importance of an in-depth morphological study of the kidneys in the presence of a tumor with an integrated approach to the treatment of patients.

Spontaneous remission of idiopathic minimal change disease in a cat

Case summary

A 5-year-old female neutered domestic mediumhair cat presented with acute onset hyporexia, lethargy, ascites, hypoalbuminaemia and ventral subcutaneous oedema. Further investigations revealed a bicavitary effusion, myocardial injury, hypercholesterolaemia and concurrent marked proteinuria. A panel of infectious disease tests yielded negative results. Nephrotic syndrome was suspected and renal biopsies were performed. Histopathology and electron microscopy confirmed a diagnosis of minimal change disease (MCD). The patient was successfully managed with benazepril, clopidogrel and a veterinary prescription renal diet. Follow-up two weeks later documented almost complete resolution of the cardiac abnormalities, absence of clinical signs and marked improvement in clinicopathological findings. The hypoalbuminaemia and proteinuria had resolved two months after presentation. At the time of writing, 13 months post-admission, the cat remained asymptomatic with no evidence of disease relapse.

Relevance and novel information

MCD is rarely described in the veterinary literature, with only four cases reported to date. To our knowledge, this report describes the first case of successfully treated MCD-associated nephrotic syndrome in a cat without the use of glucocorticoid treatment.

Chronic Kidney Disease and Cancer: Inter-Relationships and Mechanisms

Chronic kidney disease (CKD) has been recognized as an increasingly serious public health problem globally over the decades. Accumulating evidence has shown that the incidence rate of cancer was relatively higher in CKD patients than that in general population, which, mechanistically, may be related to chronic inflammation, accumulation of carcinogenic compounds, oxidative stress, impairment of DNA repair, excessive parathyroid hormone and changes in intestinal microbiota, etc. And in patients with cancer, regardless of tumor types or anticancer treatment, it has been indicated that the morbidity and incidence rate of concomitant CKD was also increased, suggesting a complex inter-relationship between CKD and cancer and arousing increasing attention from both nephrologists and oncologists. This narrative review focused on the correlation between CKD and cancer, and underlying molecular mechanisms, which might provide an overview of novel interdisciplinary research interests and the potential challenges related to the screening and treatment of CKD and cancer. A better understanding of this field might be of help for both nephrologists and oncologists in the clinical practice.

Critical evaluation of cancer risks in glomerular disease

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The increased cancer incidence in patients with glomerular disease can be secondary to an intrinsic immune dysfunction associated with the disease or/and extrinsic factors, especially immunosuppressants.

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Paraneoplastic glomerulopathy is sometimes misdiagnosed as primary glomerulopathy.

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The treatment for paraneoplastic glomerulopathy is different from primary glomerular disease.

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In membranous nephropathy, serum circulating autoantibodies against PLA2R and THSD7A, immunohistochemical tissue markers for glomerular PLA2R, THSD7A and specific types of immunoglobulin G (IgG) may be used for identifying underlying malignancies.

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A scheme of screening of cancers frequently reported in the setting of glomerular disease is important.

The increased cancer incidence in patients with glomerular disease can be secondary to an intrinsic immune dysfunction associated with the disease or/and extrinsic factors, especially immunosuppressants. The treatment for paraneoplastic glomerulopathy is different from primary glomerular disease. Immunosuppressive therapy often used for primary glomerulopathy may aggravate concomitant cancers in patients with paraneoplastic glomerulopathy. In membranous nephropathy (MN), measurement of serum circulating autoantibodies against podocyte transmembrane glycoprotein M-type phospholipase A2 receptor (PLA2R) and thrombospondin type 1 domain-containing 7A (THSD7A), immunohistochemical staining of kidney tissue for glomerular PLA2R, THSD7A, neural epidermal growth factor-like 1 protein (NELL-1) and specific types of immunoglobulin G (IgG) may be useful adjuncts when screening for underlying malignancies. This review addresses overall cancer risks in individuals with glomerular diseases and employment of biomarkers available for MN. We propose a scheme of screening of cancers frequently reported in the setting of glomerular disease.

Rhein Inhibits NF-κB Signaling Pathway to Alleviate Inflammatory Response and Oxidative Stress of Rats with Chronic Glomerulonephritis

Objective

To explore the effect and mechanism of rhein on chronic glomerulonephritis (CGN).

Method

Twenty-four eight-week-old male SD rats were randomly divided into following 4 groups (6 rats in each group): control group, CGN group, rhein group, and benazepril (Ben) group. And 5 mg/mL of cationization-bovine serum albumin (C-BSA) was mixed with an equal volume of Freund's incomplete adjuvant for the preparation of 2.5 mg/mL of C-BSA solution. The rat model of CGN was established by injection of C-BSA for six weeks. Calculation of the renal index in rats was conducted. Biochemical detection was performed to measure the level of 24 h urinary protein, blood urea nitrogen (BUN), serum creatinine (SCr), and serum albumin (ALB) of the rats, as well as the level of malondiadehyde (MDA), superoxide (SOD), and glutathione peroxidase (GSH-Px) in the kidney tissue. Hematoxylin and eosin (H&E) staining was utilized to measure histological changes in the kidney of the rats. The level of TNF-α, IL-1β, IL-6, and ICAM-1 in rat kidney tissues was determined by enzyme-linked immunosorbent assay (ELISA). Western blot was applied to check the expression of NF-κB in the nucleus and cytoplasm as well as the expression of IκBα and p-IκBα in rat kidney tissues.

Results

Rhein could decline urinary protein, restore blood biochemical parameters, and protect renal tissue in rats with CGN. Besides, rhein could inhibit the activity of the NF-κB signaling pathway in rats with CGN and could alleviate the inflammatory response and oxidative stress level at the same time.

Conclusion

Rhein alleviates inflammatory responses and oxidative stress in rats with CGN. It also provides a theoretical basis and data support for the therapeutic drugs for CGN.

Paraneoplastic Glomerular Diseases

Paraneoplastic glomerular diseases (GNs) are rare manifestations in patients with underlying hematologic and solid organ malignancies and can occur before or after the detection of cancer. In the absence of established algorithms for investigation and reliable tests, they remain difficult to diagnose. Given the heterogeneity and infrequency of cases, the pathogenesis of most paraneoplastic GNs is poorly understood. Most of our recent understanding of paraneoplastic GNs has emerged from the discovery of target antigens in membranous nephropathy such as thrombospondin type-1 domain-containing protein 7A and neural epidermal growth factor-like 1 protein that appear to be promising in differentiating a primary vs paraneoplastic cause of membranous nephropathy. Treatment of paraneoplastic GNs is usually directed at the underlying malignancy. This review will focus on the epidemiology, pathogenesis, and diagnosis of paraneoplastic glomerular processes.

Cancer risk in patients with IgA nephropathy: a Swedish population-based cohort study

BACKGROUND

IgA nephropathy (IgAN) is the most common primary glomerulonephritis affecting all ages and both sexes, but there is a lack of studies on its association with cancer and whether it is a paramalignant condition.

METHODS

In a Swedish population-based cohort study we compared the risk of cancer among 3,882 biopsy-verified IgAN patients diagnosed during 1974-2011 with 19,341 reference individuals and followed them until 2015. Cox regression was used to estimate hazard ratios (HRs) for cancer in IgAN patients versus controls, and conditional logistic regression assessed the risk of cancer before the IgAN was confirmed.

RESULTS

During a median follow-up of 12.6 years, 488 (12.6%) patients with IgAN and 1,783 (9.2%) matched reference individuals were diagnosed with cancer (HR 1.70; 95% confidence interval, 95%CI, 1.52-1.89). The increased risk was only seen in IgAN patients developing end stage renal disease (ESRD), with an HR of 4.01 (95%CI 3.33-4.82) for any cancer and HR of 2.22 (95%CI 1.79-2.75) when excluding non-melanoma skin cancer (NMSC). Non-ESRD IgAN patients did not have an increased overall cancer risk (HR 1.13; 95%CI 0.99-1.30). There was no increased risk of cancer preceding IgAN diagnosis (odds ratio 1.10; 95%CI 0.92-1.32).

CONCLUSION

We found no support for IgAN being a paramalignant condition. There was an increased risk of cancer in IgAN patients, but only for those with ESRD. Our results indicate approximately 6 extra cancer case per 100 IgAN patients with ESRD per 10 years, or >17 extra cases if including NMSC as well.

Nivolumab-associated glomerular endothelial injury in a patient with gastric cancer

A 68-year-old male with gastric cancer was treated with tegafur/gimeracil/oteracil and oxaliplatin for 6 months. Thereafter, he was treated with paclitaxel and ramucirumab for 3 months. However, neither regimen had much effect. Thus, he was treated with nivolumab for 2 months, but he developed proteinuria, microhematuria, and an acute kidney injury. A kidney biopsy revealed occasional swollen endothelial cells and proliferating mesangial cells. Few abnormal findings were seen in the tubules or interstitial tissue. Immunofluorescent staining showed segmental immunoglobulin A and complement component 3 deposition, in the mesangial area. Electron microscopy showed a small amount of electron-dense deposits in the paramesangial area and swollen endothelial cells. Mesangial interposition, the loss of endothelial cell fenestration, and subendothelial edema were also observed. Furthermore, foot process effacement and villous transformation of epithelial cells were noted. After the discontinuation of nivolumab, the patient's renal function gradually improved, and his proteinuria disappeared. Nivolumab treatment was restarted at that time because of cancer progression; however, it was ineffective. No occult blood was detected from 7 months after the administration of the last dose of nivolumab. This is a unique case, in which a kidney biopsy revealed evidence of nivolumab-associated glomerular endothelial injury.

Collapsing focal segmental glomerulosclerosis in a patient with oral cavity cancer: A case report

RATIONALE

Focal segmental glomerulosclerosis (FSGS) is one of the most common glomerular diseases, leading to end-stage renal disease. Among the 5 variants of FSGS, the collapsing variant is rare and has the worst prognosis. Solid and hematologic malignancies are associated with glomerular diseases, such as membranous nephropathy, minimal change disease, and FSGS. However, squamous cell carcinoma of the oral cavity is rarely associated with nephrotic syndrome, especially FSGS.

PATIENT CONCERNS

A 55-year-old woman diagnosed with oral cavity cancer presented with generalized edema with heavy proteinuria and renal dysfunction after neoadjuvant chemotherapy and wide surgical excision.

DIAGNOSIS

Renal biopsy shows segmental or global collapse of glomerular capillaries with marked hyperplasia and swelling of overlying epithelial cells, suggesting a collapsing variant of FSGS.

INTERVENTIONS

After the renal biopsy, we prescribed oral prednisolone at a dose of 1 mg/kg/day. Despite immunosuppressive treatment, renal function deteriorated, and hemodialysis was started.

OUTCOMES

After 23 sessions of hemodialysis and high-dose oral glucocorticoid treatment, renal function gradually improved, and oral glucocorticoid therapy was discontinued after 8 months. Currently, this patient is in a cancer-free state and has normal renal function without proteinuria.

LESSONS

Unusual collapsing FSGS might be associated with neoadjuvant chemotherapy and wide surgical excision in patients with oral cavity cancer. Proper diagnostic workup, such as renal biopsy and high-dose glucocorticoid therapy, might have helped recover from nephrotic syndrome and acute renal injury in cancer patients.

More than ancillary records: clinical implications of renal pathology examination in tumor nephrectomy specimens

Background

Nephrectomy is the management of choice for the treatment of renal tumors. Surgical pathologists primarily focus on tumor diagnosis and investigations relating to prognosis or therapy. Pathological changes in non-neoplastic tissue may, however, be relevant for further management and should be thoroughly assessed.

Methods

Here, we examined the non-neoplastic renal parenchyma in 206 tumor nephrectomy specimens for the presence of glomerular, tubulo-interstitial, or vascular lesions, and correlated them with clinical parameters and outcome of renal function.

Results

We analyzed 188 malignant and 18 benign or pseudo-tumorous lesions. The most common tumor type was clear cell renal cell carcinoma (CCRCC, n = 106) followed by papillary or urothelial carcinomas (n = 25). Renal pathology examination revealed the presence of kidney disease in 39 cases (18.9%). Glomerulonephritis was found in 15 cases (7.3%), and the most frequent was IgA nephropathy (n = 6; 2.9%). Vasculitis was found in two cases (0.9%). In 15 cases we found tubulo-interstitial nephritis, and in 9 severe diabetic or hypertensive nephropathy. Partial nephrectomy was not linked to better eGFR at follow-up. Age, vascular nephropathy, glomerular scarring and interstitial fibrosis were the leading independent negative factors influencing eGFR at time of surgery, whereas proteinuria was associated with reduced eGFR at 1 year.

Conclusion

Our large study population indicates a high incidence of renal diseases potentially relevant for the postoperative management of patients with renal neoplasia. Consistent and systematic reporting of non-neoplastic renal pathology in tumor nephrectomy specimens should therefore be mandatory.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40620-021-01030-0.

IgA Nephropathy with Dominant IgA2 Deposition Accompanied by Mantle Cell Lymphoma

Malignant lymphoma is rarely complicated by secondary IgA nephropathy. We encountered a 74-year-old man with rapidly progressive glomerulonephritis due to IgA nephropathy with predominant deposition of IgA2, instead of IgA1, in the glomerulus that was eventually diagnosed as secondary IgA nephropathy due to mantle cell lymphoma. Renal impairment was improved by chemotherapy for the mantle cell lymphoma. IgA came from the colonic mucosa that was stimulated by the infiltrated lymphoma cells, instead of the tumor itself. We should consider mantle cell lymphoma as a cause of secondary IgA nephropathy, although its prevalence may not be very high.

Renal Diseases Associated with Hematologic Malignancies and Thymoma in the Absence of Renal Monoclonal Immunoglobulin Deposits

In addition to kidney diseases characterized by the precipitation and deposition of overproduced monoclonal immunoglobulin and kidney damage due to chemotherapy agents, a broad spectrum of renal lesions may be found in patients with hematologic malignancies. Glomerular diseases, in the form of paraneoplastic glomerulopathies and acute kidney injury with various degrees of proteinuria due to specific lymphomatous interstitial and/or glomerular infiltration, are two major renal complications observed in the lymphoid disorder setting. However, other hematologic neoplasms, including chronic lymphocytic leukemia, thymoma, myeloproliferative disorders, Castleman disease and hemophagocytic syndrome, have also been associated with the development of kidney lesions. These renal disorders require prompt recognition by the clinician, due to the need to implement specific treatment, depending on the chemotherapy regimen, to decrease the risk of subsequent chronic kidney disease. In the context of renal disease related to hematologic malignancies, renal biopsy remains crucial for accurate pathological diagnosis, with the aim of optimizing medical care for these patients. In this review, we provide an update on the epidemiology, clinical presentation, pathophysiological processes and diagnostic strategy for kidney diseases associated with hematologic malignancies outside the spectrum of monoclonal gammopathy of renal significance.

Anti-Neutrophil Cytoplasmic Antibody-Associated Glomerulonephritis and Malignancy: A Case of a Patient Diagnosed with Renal Failure and Pulmonary Carcinoma Concurrently

A 70-year-old man presented with proteinuria, microscopic hematuria, and an increased level of serum creatinine. A systemic workup revealed that the patient had bronchogenic carcinoma and anti-neutrophil cytoplasmic antibody (ANCA)-associated glomerulonephritis concurrently. Despite the increase in the cumulative number of publications on paraneoplastic glomerulopathies, an awareness of the link between cancer and ANCA-associated glomerulonephritis is lacking. We strongly recommend the accumulation of more cases similar to our own, thereby allowing us to clarify the management strategies as well as the nature of this disease condition more precisely.

Spectrum of cancer patients receiving renal biopsy

BACKGROUND

The frontier of onco-nephrology, particularly renal complications of cancer and treatment, remains unexplored. We revisit the fundamental tool of diagnosing kidney disease, renal biopsy, in cancer patients with renal manifestation.

METHODS

Patients who received renal biopsy from July 2015 to July 2019 were analyzed. Primary outcomes included end-stage renal disease (ESRD), mortality, and catastrophic outcome defined as either ESRD or mortality. A Cox proportional hazards model and Kaplan-Meier technique were used to assess the association with outcome measurements and survival analyses. Immunosuppression after renal biopsy and response to the treatment were evaluated.

RESULTS

Among the 77 patients, the median age was 66 years (interquartile range [IQR] 59-73 years) and 46 (59.7%) were male. At the time of renal biopsy, 57 patients (74%) had various degrees of renal insufficiency. Tubulointerstitial damage score, quantified by renal pathology, were associated with higher hazards of ESRD (hazard ratio [HR], 1.77; 95% confidence interval [95% CI], 1.20 to 2.61; P = 0.004) and catastrophic outcome (HR, 1.30; 95% CI, 0.99 to 1.70; P = 0.058). The response rate to immunosuppression was lower in those diagnosed with tubulointerstitial nephritis (1 of 4 patients, 25%) than those with glomerulopathy (10 of 20 patients, 50%).

CONCLUSION

Renal biopsy may improve diagnostic accuracy and assist in treatment guidance of cancer patients with renal manifestation. Renal biopsy should be encouraged with clinical indication. Collaboration between oncologists and nephrologists is of paramount importance to provide more comprehensive care for caner patients.

An elderly-onset neuroblastoma concomitant with minimal change nephrotic syndrome: the first autopsy case report

BACKGROUND

Neuroblastoma is a well-known embryonal cancer; however, adult-onset neuroblastomas are rare. The systemic symptoms are related to catecholamine excretion or intraabdominal mass effects. Only two cases of neuroblastoma with nephrotic syndrome have previously been reported. We herein present the first autopsy case of neuroblastoma in an older individual associated with minimal change nephrotic syndrome.

CASE PRESENTATION

A 63-year-old man was admitted to our hospital for investigation of general fatigue. His renal function was normal and his urine was negative for protein. A computed tomography scan showed a renal tumor and intraabdominal lymph node swelling. Approximately 4 months after admission, he suddenly developed acute renal failure and severe proteinuria, and hemodialysis was instituted. A computed tomography scan revealed an increase in the size of the renal tumor and lymph nodes. He died 1 month later and an autopsy was performed. The tumor exhibited diffuse proliferation of tumor cells with scant cytoplasm, namely small blue cell tumor with rosette formation. As a result of immunohistochemical study, a neuroblastoma was diagnosed. Despite the patient's severe renal failure, most glomeruli showed no remarkable changes. The tubular epithelium exhibited detachment and vacuolation. Electron microscopic study of the glomeruli showed diffuse effacement of the foot processes. These features indicate a diagnosis of minimal change nephrotic syndrome with acute tubular injury.

CONCLUSIONS

Minimal change nephrotic syndrome is the most common renal manifestation associated with lymphoproliferative malignancies. We here present an extremely rare case of adult-onset neuroblastoma with minimal change nephrotic syndrome.

The histopathological spectrum of kidney biopsies in patients with thymoma and myasthenia gravis: a report of 24 biopsies from a single institution

Background

Nephropathy in patients with thymic diseases such as thymoma and myasthenia gravis (MG) is rare and has been described mostly as isolated case reports. Here we evaluate a series of kidney biopsies from patients with thymoma and/or MG from a single institution in order to better define the spectrum and relative frequencies of thymic disease–associated nephropathies.

Methods

We conducted a retrospective case series study of 32 462 native kidney biopsies from January 2005 through December 2019 at Cedars-Sinai Medical Center, Los Angeles, CA, USA.

Results

Twenty-four biopsy specimens (0.07%) from patients with a history of thymoma and/or MG were identified. Two patients had repeat biopsies. The most common pathologic diagnosis that could be immunologically attributed to thymic disease was minimal change disease (MCD; 45%), followed by tubulointerstitial nephritis (TIN; 14%), immune complex (IC)-mediated glomerulonephritis (9%), membranous nephropathy (5%) and immunoglobulin A (IgA) nephropathy (5%). Interestingly, 50% of the MCD and 67% of TIN cases concomitantly showed mild IgG-dominant IC deposition in mesangial areas and/or in tubular basement membranes. In the two patients with repeat biopsies, mild mesangial IC deposition developed in the MCD patient but disappeared in the TIN patient with the second biopsy. Pathologic diagnoses unlikely related to the underlying thymic disease were diabetic glomerulosclerosis (9%), acute tubular necrosis (9%) and monoclonal Ig deposition disease (5%).

Conclusions

Thymic disease is associated with a wide spectrum of kidney diseases affecting the glomerular and tubulointerstitial compartments, often with low-grade IC deposition. These findings suggest a role of immunologic dysregulation in the pathogenesis of thymic disease–associated nephropathy.

Lung Cancer Cell-Derived Secretome Mediates Paraneoplastic Inflammation and Fibrosis in Kidney in Mice

Simple Summary

Paraneoplastic nephrotic syndrome is a complication arising in lung cancer patients. In the present study, we established an LLC1 cell orthotopic xenograft C57BL/6 mice model to translation paraneoplastic nephrotic syndrome (PNS). The pathological aspects of PNS were characterized in TGF-β signaling-engaged renal fibrosis, and renal inflammation with IL-6 expression in kidney. To reveal how the lung cancer cells remotely drive pathogenic progression, secretome derived from LLC1 cells and A549 cells were proteomically profiled. Additionally, the secretome profiling was subjected to diseases and biofunctions assessment by Ingenuity Pathway analysis (IPA). As matter of secretome profiling and IPA prediction, the Fibronectin, C1r, and C1s are potential of nephrotoxicity linked to paraneoplastic effects on glomerular pathogenesis in these lung cancer mice.

Abstract

Kidney failure is a possible but rare complication in lung cancer patients that may be caused by massive tumor lysis or a paraneoplastic effect. Clinical case reports have documented pathological characteristics of paraneoplastic syndrome in glomeruli, but are short of molecular details. When Lewis lung carcinoma 1 (LLC1) cells were implanted in mice lungs to establish lung cancer, renal failure was frequently observed two weeks post orthotopic xenograft. The high urinary albumin-to-creatinine ratio (ACR) was diagnosed as paraneoplastic nephrotic syndrome in those lung cancer mice. Profiling the secretome of the lung cancer cells revealed that the secretory proteins were potentially nephrotoxic. The nephrotoxicity of lung cancer-derived secretory proteins was tested by examining the pathogenic effects of 1 × 10⁶, 2 × 10⁶, and 5 × 10⁶ LLC1 cell xenografts on the pathogenic progression in kidneys. Severe albuminuria was present in the mice that received 5 × 10⁶ LLC1 cells implantation, whereas 10⁶ cell and 2 × 10⁶ cell-implanted mice have slightly increased albuminuria. Pathological examinations revealed that the glomeruli had capillary loop collapse, tumor antigen deposition in glomeruli, and renal intratubular casts. Since IL-6 and MCP-1 are pathologic markers of glomerulopathy, their distributions were examined in the kidneys of the lung cancer mice. Moderate to severe inflammation in the kidneys was correlated with increases in the number of cells implanted in the mice, which was reflected by renal IL-6 and MCP-1 levels, and urine ACR. TGF-β signaling-engaged renal fibrosis was validated in the lung cancer mice. These results indicated that lung cancer cells could provoke inflammation and activate renal fibrosis.

Functional Metabolomics Analysis Elucidating the Metabolic Biomarker and Key Pathway Change Associated With the Chronic Glomerulonephritis and Revealing Action Mechanism of Rhein

Chronic glomerulonephritis (CGN) as the culprit of kidney failure can increase the mortality of critically ill patients and seriously threatens people’s health all over the world. This study using metabolomics strategy is to reveal the potential therapeutic mechanism-related targets to evaluate the effects of rhein (RH) on CGN rats. Changes of serum metabolites and pathways were analyzed by non-targeted metabolomic method based on liquid chromatography-mass spectrometry (LC-MS) combined with ingenuity pathway analysis. In addition, the levels of biochemical indicators were also detected. A total of 25 potential biomarkers were identified to express serum metabolic turbulence in CGN animal model, and then 16 biomarkers were regulated by RH trending to the normal states. From metabolite enrichment and pathway analysis, pharmacological activity of RH on CGN were mainly involved in six vital metabolic pathways including phenylalanine, tyrosine and tryptophan biosynthesis, phenylalanine metabolism, arachidonic acid metabolism, tricarboxylic acid cycle (TCA cycle), alanine, aspartate, and glutamate metabolism, arginine and proline metabolism. It suggested CGN treatment with RH, which may be mediated via interference with metabolic pathway such as amino acid metabolism, arachidonic acid metabolism, and TCA cycle to regulating inflammation, oxidation response and immune regulation against CGN. It showed that metabolomics method offer deeply insight into the therapeutic mechanisms of natural product.

Focal Segmental Glomerulosclerosis Preceding Type 2 Papillary Renal Cell Carcinoma

Renal cell carcinoma (RCC) is the predominant renal malignancy in adults. Of the four general subtypes, papillary renal cell carcinoma (P-RCC) is the second most common and can be subdivided into type I, type II, and a mixture of type I and II. Focal segmental glomerulosclerosis (FSGS) is the most common glomerulopathy at all ages, and it can be seen as a paraneoplastic syndrome. RCC, in general, is known to present with many paraneoplastic syndromes, and glomerulopathies are among these. Rarely, RCC and glomerulopathies may overlap in the same patient. Here, we report a 58-year-old male with a past medical history of FSGS and chronic kidney disease (CKD), stage III, who was found to have an incidental renal mass that was later diagnosed as type II P-RCC. The histology showed pseudostratified tumor cells with an eosinophilic cytoplasm that formed papillary configurations and displayed areas of necrosis. The prior FSGS diagnosis exhibited segmental sclerosis, refractory tufts, and capillary membrane wrinkling. A period of 1.5 years elapsed between the diagnosis of the glomerulopathy and the malignancy. The tumor was found to be at stage TIb. To our knowledge, this may be the first reported case of usual-type FSGS as paraneoplastic glomerulopathy (PG) preceding P-RCC. Because FSGS only sparingly affects the kidney and is a common glomerulopathy in adults, it is reasonable to complete comprehensive diagnostic studies and commence medically necessary treatment, especially in the background of other renal comorbidities. These preexisting comorbidities may be associated with malignancy very early in its course. The probability of RCC-associated paraneoplastic glomerulopathy is low, which means an already incidentally found renal mass may conceal a serpentine paraneoplastic syndrome. A more developed understanding of these manifestations can lead experienced clinicians to suspect and possibly uncover an insidious RCC before it advances.

Concurrent minimal change disease and retroperitoneal liposarcoma successfully treated by tumor resection and steroid therapy

A 54-year-old Japanese woman developed simultaneous abdominal distension and bilateral leg edema. Her medical history and results of periodic medical check-up were unremarkable. Blood tests revealed severe hypoproteinemia and acute kidney injury, and urinalysis revealed 4+ proteinuria and 2+ hematuria. Abdominal computed tomography revealed a large intra-abdominal mass with fat tissue density. She underwent emergency tumor excision, splenectomy, and distal pancreatectomy. However, hypoproteinemia and acute kidney injury worsened. Therefore, she was transferred to the nephrology division for confirmation of diagnosis and for treatment of acute kidney injury and nephrotic syndrome. We conducted percutaneous kidney biopsy and diagnosed minimal change disease (MCD). Intravenous prednisolone was started, and heavy proteinuria and systemic edema were gradually alleviated. She achieved complete remission 2 months later, and oral prednisolone was tapered. Histopathological diagnosis of abdominal tumor was dedifferentiated liposarcoma of retroperitoneal origin. Immunohistochemical staining revealed strong expression of vascular endothelial growth factor in the tumor cells in the dedifferentiated component. Currently, her clinical course is stable without recurrence of liposarcoma and nephrotic syndrome. MCD develops in patients with Hodgkin's lymphoma, solid organ cancers, hematological malignancies, and thymoma, whereas concurrent MCD and liposarcoma are rare. Remission of nephrotic syndrome and normalized kidney function induced by steroid therapy are important for better management of patients with malignancy.

Focal Segmental Glomerulosclerosis in Waldenström's Macroglobulinemia

Renal involvement in Waldenström's macroglobulinemia is a rare manifestation. Although most renal involvement is due to monoclonal immune deposits, pathology can also be unrelated to it. Here, we describe a 68-year-old female with a history of Waldenström's macroglobulinemia who presented with generalized edema and nephrotic range proteinuria. A renal biopsy showed findings consistent with focal segmental glomerulosclerosis. Treatment with oral prednisone leads to the resolution of proteinuria. This case highlights the importance of identifying pathology that might not be directly related to monoclonal gammopathy, which could have implications on the management.

Glomerular Diseases Associated with Malignancies: Histopathological Pattern and Association with Circulating Autoantibodies

Aim: Glomerular diseases (GD) associated with malignancies (AM, GDAM) have unique features, which are important to recognize, in the light of the progress made in cancer therapy. We aimed to describe the clinical and histopathological characteristics of patients with GDAM in relation to the presence of circulating autoantibodies, pointing to potential immune pathogenic pathways connecting cancer to GD. Materials and Methods: The included patients were studied retrospectively on the basis of a kidney biopsy proving GD and a related biopsy to establish the diagnosis of AM. We recorded patients’ demographics, serological and laboratory parameters, histopathological findings, and the type of malignancy, GD, and therapy. Results: In total, 41 patients with GDAM, with a mean age of 63.1 (±10.7) years, were studied. In 28 (68.3%) cases, GD was associated with a solid tumor, and in 13 (31.7%) patients with a lymphoid malignancy. The most frequent histopathological pattern was membranous nephropathy (43.9%). Overall, at the time of GD diagnosis, 17% of the patients were positive for antinuclear antibodies (ANA), and 12.2% for antineutrophil cytoplasmic autoantibodies (ANCA), all against myeloperoxidase (MPO). In addition, 93.3% of the patients who had membranous nephropathy were negative for transmembrane glycoprotein M-type phospholipase A₂ receptor (PLA₂R) antibody. Sixteen patients (39.0%) presented with acute nephritic syndrome, of whom five (31.25%) developed rapidly progressive glomerulonephritis. In a mean follow-up time of 36.1 (±28.3) months, nine (21.95%) patients ended up with end-stage kidney disease, and eight (19.5%) died. Conclusion: We found that 3.2% of patients who underwent a native kidney biopsy in our institution during the past decade, for any reason, were identified as having some type of GD associated with a malignancy. Serology indicated a significant presence of ANA or MPO-ANCA antibodies in patients with nephritic syndrome and the absence of PLA₂R antibodies in patients with membranous nephropathy.

Primary Membranous Glomerulonephritis: The Role of Serum and Urine Biomarkers in Patient Management

The detection of phospholipase A2 receptor (PLA2R) and thrombospondin domain containing 7A THSD7A among primary membranous glomerulonephritis (MGN) patients transformed the diagnosis, treatment monitoring, and prognosis. Anti-PLA2R can be detected in 70-90% of primary MGN patients while anti-THSD7A in 2-3% of anti-PLA2R negative primary MGN patients depending on the technique used. Serum and urine samples are less invasive and non-invasive, respectively, and thus can detect the presence of anti-PLA2R and anti-THSD7A with higher sensitivity and specificity, which is significant in patient monitoring and prognosis. It is better than exposing patients to a frequent biopsy, which is an invasive procedure. Different techniques of detection of PLA2R and THSD7A in patients' urine and sera were reviewed to provide newer and alternative techniques. We proposed the use of biomarkers (PLA2R and THSD7A) in the diagnosis, treatment decision, and follow-up of patients with primary MGN. In addition, other prognostic renal biomarkers like retinol binding protein (RBP) and beta-2 microglobulin were reviewed to detect the progression of renal damage for early intervention.

Comparison of cancer prevalence between patients with glomerulonephritis and the general population at the time of kidney biopsy

Glomerulonephritis (GN) has been associated with many solid and hematologic malignancies. However, cancer prevalence at the time of GN diagnosis has been rarely examined. We aimed to evaluate the cancer prevalence in patients with GN at the time of kidney biopsy and to compare the results to those of the general population. A total of 1,155 patients who underwent kidney biopsy between 2003 and 2017 were included. We investigated patients diagnosed with cancer within one month of kidney biopsy. The occurrence of cancer was compared with that of the Korean general population using the observed-to-expected rates (O/E ratio). Twenty-nine patients with GN had cancer. The mean age of patients with and without cancer was 49 and 66 years old, respectively. The proportion of male patients with and without cancer was 49.4% and 58.6%, respectively. The glomerular filtration rate was different between the groups (78.1 ± 37.0, 58.0 ± 43.6 ml/min/1.73 m2, p = 0.006), but the urine protein/creatinine ratio was not (3.21 ± 4.01, 5.38 ± 7.47 g/gCr, p = 0.172). Immunoglobulin A nephropathy (IgAN) was the most common GN (37.9%), followed by membranous GN (13.5%), focal segmental glomerulosclerosis (9.7%), minimal change disease (9.2%), amyloidosis (1.2%). Amyloidosis was the most common GN associated with malignancy (20.7%). In patients with amyloidosis, cancer was observed almost 28 times more than expected and these patients showed higher cancer occurrence than patients with other GN (Relative Risk [RR]: 15.73; 95% confidence interval [CI]: 4.82-51.30; p < 0.01). Cancer occurrence was three times greater in GN patients aged > 50 years compared to the general population (O/E ratio: 3.42; 95% CI: 1.37-5.46; p = 0.027). Patients with GN, especially amyloidosis, have higher risk of cancer than the general population at the time of GN diagnosis. Older age (> 50 years) was one of the major determinants of the presence of cancer in GN patients.

Duodenal neuroendocrine tumour associated with minimal change glomerulonephritis

Paraneoplastic glomerular disease is an increasingly well-recognised entity, and a wide range of both solid and haematological malignancies have been implicated. The most common glomerular disease associated with cancer is membranous nephropathy. Only a few case reports have described an association between neuroendocrine tumours (NETs) and glomerulonephritis and only one paediatric case in relation to minimal change disease. A 76-year-old woman with a well-differentiated duodenal NET presented with nephrotic syndrome and renal biopsy was suggestive of minimal change glomerulonephritis. Standard therapy with corticosteroids brought little benefit, but a dramatic improvement was seen following initiation of systemic anticancer therapy with lanreotide, a somatostatin analogue. Less than 1 month after initiation of lanreotide, the patient was no longer in a nephrotic state, and after a further 2 months of follow-up had shown no sign of relapse.

Hypertensive nephropathy is associated with an increased risk of myeloma, skin, and renal cancer

Previous studies suggest an increased cancer risk in hypertension. Patients with hypertensive nephropathy have not been studied. A national registry study was performed to assess the presence and size of this association. Clinical data and cancer diagnoses for all patients with biopsy-proven hypertensive nephropathy between 1985 and 2015 in Denmark were extracted from four national registries and compared with age- and sex-adjusted national cancer rates. The risk of cancer was twice the background population. It was raised for renal cancer (odds ratio 10.4), myeloma (13.2), skin cancer (7.9), and other/unspecified (1.8). No increase in incidence was seen until 1 year before renal biopsy and then rose rapidly. It was again normal 5 years after biopsy. Hypertensive nephropathy is associated with an increased risk of myeloma, skin, renal, and other cancers. Screening of patients with hypertensive nephropathy, in the presence of reduced renal function or significant proteinuria, may be indicated.

Case report: Gastric cancer-associated membranous nephropathy that recurred after complete remission and formation of peritoneal dissemination

Membranous nephropathy associated with malignant neoplasm may remit completely with treatment of the underlying disease. In such cases, recurrence is very rare. However, after a recurrence, attention should be paid to the possible recurrence of the underlying disease.

Myeloid disorders after autoimmune disease

Autoimmune diseases (ADs) are associated with an increased risk not only of lymphoproliferative disorders but also of myeloid malignancies. The excess risk of myelodysplastic syndromes and/or acute myeloid leukemia is observed across several AD types, including systemic lupus erythematosus, rheumatoid arthritis, inflammatory bowel disorders, multiple sclerosis, among others. The risk of developing myeloid neoplasms (MNs) is dependent on several variables, including the specific AD type, chronicity and severity of the AD, type and duration of exposure of disease modifying anti-rheumatic drugs or cytotoxics/immunosuppressives, and genetic predisposition risk. Putative triggering factors linking AD to elevated MN risk include AD-directed medications, shared genetic susceptibilities between the two disease entities, and chronic immune stimulation or bone marrow infiltration by the AD. Molecular mechanisms underpinning leukemogenesis remain largely speculative and warrant further investigation. Leukemias arising in patients with AD are not always 'therapy-related' in that MNs may develop in certain AD subtypes even among patients with no prior therapy exposure. Only a few studies have attempted to determine factors associated with MN development in AD but failed to demonstrate consistent characteristic clinical or paraclinical features. These reports have failed to demonstrate a clear correlation between individual agent exposure and subsequent leukemia development due to the low rates of therapy exposure compounded by the rarity of MN occurrence. Notwithstanding, the leukemogenic potential is best documented with agents such as azathioprine, cyclophosphamide, and mitoxantrone; this risk of MN development does not appear to be shared by biologic approaches such as anti-tumor necrosis factors-alpha inhibitors. In this article, we discuss plausible biologic mechanisms underlying MN pathogenesis in AD and review the data available on the development of MNs in patients with AD.

Genetics of Childhood Steroid Sensitive Nephrotic Syndrome: An Update

Advances in genome science in the last 20 years have led to the discovery of over 50 single gene causes and genetic risk loci for steroid resistant nephrotic syndrome (SRNS). Despite these advances, the genetic architecture of childhood steroid sensitive nephrotic syndrome (SSNS) remains poorly understood due in large part to the varying clinical course of SSNS over time. Recent exome and genome wide association studies from well-defined cohorts of children with SSNS identified variants in multiple MHC class II molecules such as HLA-DQA1 and HLA-DQB1 as risk factors for SSNS, thus stressing the central role of adaptive immunity in the pathogenesis of SSNS. However, evidence suggests that unknown second hit risk loci outside of the MHC locus and environmental factors also make significant contributions to disease. In this review, we examine what is currently known about the genetics of SSNS, the implications of recent findings on our understanding of pathogenesis of SSNS, and how we can utilize these results and findings from future studies to improve the management of children with nephrotic syndrome.

Paraneoplastic immunoglobulin A nephropathy and associated focal segmental glomerulosclerosis in asymptomatic low volume B-cell lymphoma - a case report

Background

Paraneoplastic glomerulonephritis is rare in haematological malignancies and tends to manifest as minimal change disease, membranous glomerulonephritis or membranoproliferative glomerulonephritis. We present the first report of immunoglobulin A nephropathy and associated focal segmental glomerulosclerosis in a patient with asymptomatic low grade B-cell lymphoma.

Case presentation

A 53 year old gentleman presented with nephrotic range proteinuria (urine protein creatinine ratio of 662 mg/mmol) on a background of type 2 diabetes mellitus (glycosylated haemoglobin: < 6%), hypertension, obesity (body mass index: 47.6 kg/m²) and degenerative spine disease. Bone marrow biopsy diagnosed a low grade B-cell lymphoma and renal biopsy was consistent with immunoglobulin A nephropathy. Lymphoma treatment with six cycles of cyclophosphamide/ rituximab/ prednisolone led to normalisation of urinary protein excretion (urine protein creatinine ratio: 14 mg/mmol at 26 months post-chemotherapy).

Conclusion

Paraneoplastic immunoglobulin A nephropathy can occur with a broad range of haematological malignancies regardless of stage. This case illustrates the importance of meticulous haematological system work-up for patients presenting with immunoglobulin A nephropathy. Recognition of paraneoplastic immunoglobulin A nephropathy and early diagnosis of associated malignancy can be life-saving.

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.

Molecular and Cellular Mechanisms for Proteinuria in Minimal Change Disease

Minimal Change Disease (MCD) is a clinical condition characterized by acute nephrotic syndrome, no evident renal lesions at histology and good response to steroids. However, frequent recurrence of the disease requires additional therapies associated with steroids. Such multi-drug dependence and frequent relapses may cause disease evolution to focal and segmental glomerulosclerosis (FSGS) over time. The differences between the two conditions are not well defined, since molecular mechanisms may be shared by the two diseases. In some cases, genetic analysis can make it possible to distinguish MCD from FSGS; however, there are cases of overlap. Several hypotheses on mechanisms underlying MCD and potential molecular triggers have been proposed. Most studies were conducted on animal models of proteinuria that partially mimic MCD and may be useful to study glomerulosclerosis evolution; however, they do not demonstrate a clear-cut separation between MCD and FSGS. Puromycin Aminonucleoside and Adriamycin nephrosis are models of glomerular oxidative damage, characterized by loss of glomerular basement membrane polyanions resembling MCD at the onset and, at more advanced stages, by glomerulosclerosis resembling FSGS. Also Buffalo/Mna rats present initial lesions of MCD, subsequently evolving to FSGS; this mechanism of renal damage is clearer since this rat strain inherits the unique characteristic of overexpressing Th2 cytokines. In Lipopolysaccharide nephropathy, an immunological condition of renal toxicity linked to B7-1(CD80), mice develop transient proteinuria that lasts a few days. Overall, animal models are useful and necessary considering that they reproduce the evolution from MCD to FSGS that is, in part, due to persistence of proteinuria. The role of T/Treg/Bcells on human MCD has been discussed. Many cytokines, immunomodulatory mechanisms, and several molecules have been defined as a specific cause of proteinuria. However, the hypothesis of a single cell subset or molecule as cause of MCD is not supported by research and an interactive process seems more logical. The implication or interactive role of oxidants, Th2 cytokines, Th17, Tregs, B7-1(CD80), CD40/CD40L, c-Mip, TNF, uPA/suPAR, Angiopoietin-like 4 still awaits a definitive confirmation. Whole genome sequencing studies could help to define specific genetic features that justify a definition of MCD as a “clinical-pathology-genetic entity.”

Concurrent isolated IgG2-positive membranous nephropathy and malignant B-cell lymphoma

A recent systematic review showed that hematological malignancy is often complicated by membranous nephropathy (MN). Histologically, the deposition of IgG subclasses other than IgG4 may imply secondary MN, such as malignancy-associated MN (M-MN). We describe a very rare case of concurrent isolated IgG2-positive MN and B-cell lymphoma. An 83-year-old woman was hospitalized at our institute for facial and lower extremity edema persisting for 2 months. Laboratory tests showed urinary protein level of 10.8 g/day, serum albumin level of 1.6 g/dl, and serum creatinine level of 2.34 mg/dl. Soon after diagnosis of nephrotic syndrome, treatment with corticosteroid was initiated, but it proved to be ineffective. Renal biopsy showed isolated IgG2-positive MN with highly infiltrated CD20-positive lymphoid cells in the kidney. Computed tomography revealed systemic lymphadenopathy, and aberrant B-cells with immunoglobulin light chain restriction were detected in peripheral blood and bone marrow, which led to the diagnosis of mature B-cell lymphoma. Although rituximab (375 mg/m²/week) was administered, the patient suddenly died from gastrointestinal bleeding on day 40 of hospitalization. It is, thus, necessary to consider hematological malignancy when a diagnosis of MN is made. Further studies are expected to elucidate the pathogenesis and to help establish the adequate treatment for this rare situation.

Concurrent renal amyloidosis and thymoma resulting in a fatal ventricular thrombus in a dog

Thymoma-associated nephropathies have been reported in people but not in dogs. In this report, we describe a dog with thymoma and concurrent renal amyloidosis. A 7-year-old castrated male Weimaraner was presented for progressive anorexia, lethargy, and tachypnea. The dog was diagnosed with azotemia, marked proteinuria, and a thymoma that was surgically removed. Postoperatively, the dog developed a large left ventricular thrombus and was euthanized. Necropsy confirmed the presence of a left ventricular thrombus and histopathology revealed renal amyloidosis. We speculate that the renal amyloidosis occurred secondary to the thymoma, with amyloidosis in turn leading to nephrotic syndrome, hypercoagulability, and ventricular thrombosis. This case illustrates the potential for thymoma-associated nephropathies to occur in dogs and that dogs suspected to have thymoma should have a urinalysis and urine protein creatinine ratio performed as part of the pre-surgical database.

Quantification of cancer risk in glomerulonephritis

Background

The association of increased cancer risk with glomerulonephritis (GN) is well known, but controversy exists concerning which types of GN are involved, and the size of the association. A national registry survey was performed to assess the size of this association, and the temporal relationship of cancer diagnosis to GN diagnosis.

Methods

All patients with biopsy-proven GN between 1985 and 2015 in Denmark were extracted from The Danish Renal Biopsy Registry and the National Pathology Data Bank. Incident cancer diagnoses between 10 years previous and 10 years subsequent to the GN diagnosis were extracted from the Danish Cancer Registry. Residence, birth and death data were obtained from the National Patient Register. Expected cancer incidence, classified according to cohort, age and sex were extracted from the Nordcan database.

Results

Nine hundred eleven cancers were diagnosed in 5594 patients. Thirty five percent were prevalent at renal biopsy. Prevalence at biopsy was 5.5% (expected 3.1%), but incidence was not increased < 1 year before biopsy. Increased cancer rates were seen for GN forms: minimal change, endocapillary, focal segmental glomerulosclerosis, mesangioproliferative, membranous, focal segmental, membranoproliferative, proliferative, ANCA-associated vasculitis, lupus nephritis and unclassified. Increased cancer rates were seen for lung, prostate, renal, non-Hodgkin lymphoma, myeloma, leukaemia and skin. The increased incidence was mainly limited to − 1 to 1 year after biopsy, but skin cancer showed an increased risk over time. Some diagnoses showed an increase 5–10 years after biopsy. Incidence was raised for patients with uraemia and nephrosis, but less for proteinuria or haematuria. Cancers in patients < 45 years were rare. The risk of developing cancer 0–3 years after biopsy for patients 45–64 years varied from 7.3% (minimal change) to 15.8% (unclassified GN); > 64 years from 11.8 (endocapillary GN) to 20.3% (unclassified). The diagnosis with the highest risk was membranoproliferative GN (8.6 & 19.6%).

Conclusions

Cancer rates are increased for many cancer and most GN diagnoses. Cancer screening for patients < 45 years and for patients without nephrosis or uraemia may not be necessary. The findings suggest that screening programs for specific GN diagnoses can be extended to other GN forms.