Specific antigen-based stratification of membranous nephropathy in patients after haematopoietic stem cell allotransplantation - a case series and literature review.

BACKGROUND: Nephrotic syndrome (NS) is a rare complication that can occur after haematopoietic stem cell transplantation (HSCT). In patients with membranous nephropathy (MN) who have undergone allogeneic HSCT, a new antigen called protocadherin FAT1 has been identified. Our objective is to present a case series of MN patients after HSCT with a novel antigen-based stratification. CASE PRESENTATIONS: Patients who developed full-blown NS due to MN after an HSCT were enrolled in the University Hospital Centre Zagreb study. The first two patients were treated with an HSCT for acute myeloid leukaemia, and both developed NS after cessation of graft versus host disease (GVHD) prophylaxis. The first patient had reduced kidney function, while the second had completely preserved function. Kidney biopsy showed MN with only subepithelial deposits. A thorough examination revealed that there was no secondary cause of the disease. The patients achieved complete remission after undergoing immunosuppression treatment. The third patient underwent HSCT for acute lymphoblastic leukaemia. He developed both acute and chronic GVHD and also experienced avascular hip necrosis. After sixteen years, the patient developed NS with preserved kidney function. The kidney specimen showed membranous nephropathy (MN) with mesangial and subepithelial deposits. Extensive research was conducted, but no secondary cause for the MN was detected. All three cases tested negative for anti-PLA2R antibodies. Biopsy tissue samples were analysed using laser microdissection and tandem mass spectrometry of glomeruli for the detection of different specific antigens. Patients one and two tested positive for FAT1, whereas patient three tested positive for PCSK6. CONCLUSIONS: MN can develop at various time intervals after HSCT. Specific antigen testing can help establish the relationship between MN and HSCT. In the future, serum testing for anti-FAT1 antibodies in HSCT patients could be significant in diagnosing FAT1-associated MN, similar to how anti-PLA2R antibodies are significant in diagnosing PLA2R-associated MN.

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.

Diagnosis and treatment of secondary nephrotic syndrome with rash as the first symptom: a case report.

BACKGROUND: Membranous nephropathy (MN) is a common type of nephrotic syndrome (NS) in adults, accounting for about 20-30% of cases. Although secondary to specific factors, the coexistence of MN and mantle cell lymphoma (MCL) has been scarcely reported in clinical literature. CASE PRESENTATION: A 59-year-old Chinese male was admitted to the hospital with a generalized pruritic rash with bilateral lower extremity edema, which did not improve significantly after symptomatic treatment. He had undergone renal biopsy, and the diagnosis was thought to be secondary MN (SMN), therefore, we did a lymph node biopsy on the patient and found that MN was complicated with MCL. Soon after, the patient was admitted to the hematology department for a BR chemotherapy regimen (composed of bendamustine 90 mg/m2 BSA (body surface area), rituximab 375 mg/m2 BSA and dexamethasone 5 mg), and during the post-treatment follow-up, both his symptoms and renal function improved. CONCLUSIONS: The mechanism underlying the combination of SMN and MCL remains elusive and exceedingly rare, consequently often overlooked in clinical practice. This case serves to offer valuable clinical insights for diagnosis and treatment, while emphasizing the pivotal role of renal pathology in clinical assessment.

Case presentation: a severe case of cobalamin c deficiency presenting with nephrotic syndrome, malignant hypertension and hemolytic anemia.

BACKGROUND: The etiology of nephrotic syndrome can vary, with underlying metabolic diseases being a potential factor. Cobalamin C (cblC) defect is an autosomal recessive inborn error of metabolism caused by mutations in the MMACHC gene, resulting in impaired vitamin B12 processing. While cblC defect typically manifests with hematological and neurological symptoms, renal involvement is increasingly recognized but remains rare. CASE PRESENTATION: We describe a 7-month-old male patient presenting with fatigue and edema. His first laboratory findings showed anemia, thrombocytopenia, hypoalbuminemia and proteinuria and further examinations reveals hemolysis in peripheric blood smear. During his follow up respiratory distress due to pleural effusion in the right hemithorax was noticed. And fluid leakage to the third spaces supported nephrotic syndrome diagnosis. The patient's condition deteriorated, leading to intensive care admission due to, hypertensive crisis, and respiratory distress. High total plasma homocysteine and low methionine levels raised suspicion of cobalamin metabolism disorders. Genetic testing confirmed biallelic MMACHC gene mutations, establishing the diagnosis of cblC defect. Treatment with hydroxycobalamin, folic acid, and betaine led to remarkable clinical improvement. DISCUSSION/CONCLUSION: This case underscores the significance of recognizing metabolic disorders like cblC defect in atypical presentations of nephrotic syndrome. Early diagnosis and comprehensive management are vital to prevent irreversible renal damage. While cblC defects are more commonly associated with atypical hemolytic uremic syndrome, this case highlights the importance of considering cobalamin defects in the differential diagnosis of nephrotic syndrome, especially when associated with accompanying findings such as hemolysis. Our case, which has one of the highest homocysteine levels reported in the literature, emphasizes this situation again.

Stroke associated with primary membranous nephropathy in a young adult: Case report / Evento cerebral isquémico asociado con nefropatía membranosa primaria en un adulto joven: reporte de caso

INTRODUCTION: Stroke in young individuals is becoming increasingly prevalent worldwide. Its causes can vary widely, so a thorough investigation by a multidisciplinary team is needed. Pinpointing the precise underlying pathology responsible for the stroke yields benefits for patients, particularly in recurrent events. CASE PRESENTATION: A 38-year-old man presented to the emergency department with symptoms suggestive of stroke, including right hemiparesis, dysarthria, ataxic gait, and right central facial palsy. The brain magnetic resonance image revealed an ischemic lesion located in the left basal ganglia and near the corona radiata. Following an extensive workup, a diagnosis of nephrotic was reached. Histopathology and the exclusion of secondary causes confirmed primary membranous nephropathy as the underlying condition. The patient underwent treatment tailored to address the specific glomerulopathy, along with anticoagulation therapy and immunosuppression as per current guidelines. Subsequent assessments showed stabilization of renal function, resolution of the edema, and the absence of new thromboembolic events during follow-up. CONCLUSION: The nephrotic syndrome should be recognized as a potential underlying cause of stroke in young patients and, therefore, it should be included in the differential diagnosis during the evaluation of patients with coagulopathies. Nephrotic syndrome screening may be done by conducting a simple urinalysis readily available in most healthcare facilities. This underlines the importance of considering renal pathology in the assessment of stroke etiologies, especially when coagulation abnormalities are present.

Introducción. Los eventos cerebrovasculares en los jóvenes son un problema creciente en todo el mundo. Su etiología puede ser variada y requieren un trabajo riguroso de un equipo multidisciplinario. La identificación de la enfermedad específica que conduce al ictus tiene un impacto beneficioso en los pacientes, especialmente en aquellos con eventos recurrentes. Presentación del caso. Se presenta el caso de un hombre de 38 años que acudió al servicio de urgencias con hemiparesia derecha, disartria, ataxia y parálisis facial central derecha. La resonancia magnética cerebral reveló una lesión isquémica localizada en los ganglios basales izquierdos, cerca de la corona radiada. Después de un estudio exhaustivo, se estableció el diagnóstico de síndrome nefrótico. No obstante, al analizar las características histopatológicas y descartar otras causas secundarias, el diagnóstico final fue una nefropatía membranosa primaria. El paciente recibió tratamiento específico para su glomerulopatía, anticoagulación e inmunosupresión según las guías vigentes. Durante el seguimiento, se encontró estabilización de la función renal, el edema se resolvió y no se identificó ningún nuevo evento tromboembólico. Conclusión. El síndrome nefrótico debe considerarse entre las posibles causas del ictus en pacientes jóvenes y debería tenerse en cuenta en los estudios de coagulopatías. El tamizaje de esta enfermedad requiere únicamente un uroanálisis, el cual está disponible en la mayoría de los centros de atención de salud.

The Great Mimicker: Secondary Syphilis-Associated Nephrotic Syndrome in an Adolescent Patient.

BACKGROUND: Syphilis is long regarded as the "great mimicker" for its variety of symptoms and clinical manifestations. Rarely, it can present with renal involvement, particularly nephrotic syndrome. This is an uncommon initial presentation, particularly in pediatrics. CASE REPORT: We present the case of a 17-year-old male adolescent who presented to the emergency department with a chief symptom of abdominal pain. In addition, he was found to have a number of stigmata characteristic of both syphilis and nephrotic syndrome, including a rash and diffuse edema, particularly in the lower extremities. This led to the diagnosis of nephrotic syndrome secondary to syphilis infection. Prompt diagnosis and treatment of syphilis resulted in resolution of both kidney injury and symptoms of the underlying infection. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: This case highlights the variety of manifestations of sexually transmitted infections, particularly in the pediatric population. It demonstrates how identifying syphilis as the inciting event led to the correct treatment management for the patient. This presentation serves to teach and remind emergency physicians of the wide-ranging presentations for sexually transmitted infections, particularly syphilis, and the necessity of obtaining a sexual history even in adolescent patients.

Two successful pregnancies in a membranous nephropathy patient: Case report and literature review.

BACKGROUND: Pregnancy in patients with nephrotic syndrome presents enormous challenges to both the mother and fetus, and there are no treatment guidelines for these patients. METHODS: We show a case of a woman with anti-PLA2R antibody-positive membranous nephropathy who did not have a kidney biopsy. Her clinical course during both pregnancies was closely followed and her medications were guided. RESULTS: She gave birth to 2 healthy babies and her condition was very well controlled with the help of medication. CONCLUSION: Patients with nephrotic syndrome can have successful pregnancies after drug treatment. In addition, similar to the non-pregnant population, percutaneous kidney biopsy is not required for the diagnosis of idiopathic membranous nephropathy (IMN) in pregnant nephrotic syndrome patients with anti-PLA2R antibody positive, but the etiology of secondary MN should be excluded.

Nephrotic syndrome due to focal segmental glomerulosclerosis complicating scleroderma: a case report.

BACKGROUND: Systemic scleroderma (SSc) is an insidious autoimmune connective tissue disorder with multiorgan involvement. Renal involvement is one of the important causes of morbidity and mortality in scleroderma; however, nephrotic syndrome is reported rarely in association with SSc. We present a patient with SSc who developed focal segmental glomerulosclerosis (FSGS) as a complication of scleroderma. CASE PRESENTATION: A 59 year old Caucasian female patient, with a known history of diffuse systemic sclerosis from 8 years, presented to our clinic with symptoms of anasarca and weight gain. Her physical examination was unremarkable except for periorbital and extremity edema. Her biochemistry assessment revealed decreased serum albumin levels and elevated serum creatinine levels. A renal biopsy was performed, which showed histopathological patterns of FSGS type of nephrotic syndrome. After administration of high doses of steroid and rituximab in the course of her treatment for 6 months, her symptoms and proteinuria were improved without the occurrence of scleroderma renal crises. CONCLUSION: SSc is a complex multisystemic autoimmune disorder. SRC is the most prominent renal involvement in SSc, but other renal pathologies may also occur. Each patient should be precisely investigated since managing these renal conditions can differ significantly. Nephrotic syndrome is a rare complication of SSc, which could be managed with prompt diagnosis and steroid administration.

Post-transplant recurrence of focal segmental glomerular sclerosis: consensus statements.

Focal segmental glomerular sclerosis (FSGS) is 1 of the primary causes of nephrotic syndrome in both pediatric and adult patients, which can lead to end-stage kidney disease. Recurrence of FSGS after kidney transplantation significantly increases allograft loss, leading to morbidity and mortality. Currently, there are no consensus guidelines for identifying those patients who are at risk for recurrence or for the management of recurrent FSGS. Our work group performed a literature search on PubMed/Medline, Embase, and Cochrane, and recommendations were proposed and graded for strength of evidence. Of the 614 initially identified studies, 221 were found suitable to formulate consensus guidelines for recurrent FSGS. These guidelines focus on the definition, epidemiology, risk factors, pathogenesis, and management of recurrent FSGS. We conclude that additional studies are required to strengthen the recommendations proposed in this review.

Cell-type-specific molecular characterization of cells from circulation and kidney in IgA nephropathy with nephrotic syndrome.

Nephrotic syndrome (NS) is a relatively rare and serious presentation of IgA nephropathy (IgAN) (NS-IgAN). Previous research has suggested that the pathogenesis of NS-IgAN may involve circulating immune imbalance and kidney injury; however, this has yet to be fully elucidated. To investigate the cellular and molecular status of NS-IgAN, we performed single-cell RNA sequencing (scRNA-seq) of peripheral blood mononuclear cells (PBMCs) and kidney cells from pediatric patients diagnosed with NS-IgAN by renal biopsy. Consistently, the proportion of intermediate monocytes (IMs) in NS-IgAN patients was higher than in healthy controls. Furthermore, flow cytometry confirmed that IMs were significantly increased in pediatric patients with NS. The characteristic expression of VSIG4 and MHC class II molecules and an increase in oxidative phosphorylation may be important features of IMs in NS-IgAN. Notably, we found that the expression level of CCR2 was significantly increased in the CMs, IMs, and NCMs of patients with NS-IgAN. This may be related to kidney injury. Regulatory T cells (Tregs) are classified into two subsets of cells: Treg1 (CCR7 high, TCF7 high, and HLA-DR low) and Treg2 (CCR7 low, TCF7 low, and HLA-DR high). We found that the levels of Treg2 cells expressed significant levels of CCR4 and GATA3, which may be related to the recovery of kidney injury. The state of NS in patients was closely related to podocyte injury. The expression levels of CCL2, PRSS23, and genes related to epithelial-mesenchymal transition were significantly increased in podocytes from NS-IgAN patients. These represent key features of podocyte injury. Our analysis suggests that PTGDS is significantly downregulated following injury and may represent a new marker for podocytes. In this study, we systematically analyzed molecular events in the circulatory system and kidney tissue of pediatric patients with NS-IgAN, which provides new insights for targeted therapy in the future.

Patients with primary focal segmental glomerulosclerosis with detectable urinary CD80 are more similar to patients with minimal change disease in clinicopathological features.

BACKGROUND: Focal segmental glomerulosclerosis (FSGS) is an important cause of refractory nephrotic syndrome (NS) in children and adults. Urinary CD80 is elevated in some patients with primary FSGS, however, its clinical value is not fully clarified. This study aims to evaluate the clinical and pathological significance of urinary CD80 in patients with primary FSGS. METHODS: Sixty-one adult patients with biopsy-proven primary FSGS, with standard treatment and long-term follow up, were enrolled retrospectively. Urinary CD80, on the day of kidney biopsy, was measured using commercial ELISA kits and adjusted by urinary creatinine excretion. Their associations with clinical and pathological parameters were investigated. RESULTS: Urinary CD80 was detectable in 30/61 (49.2%) patients, who presented with a higher level of proteinuria (10.7 vs. 5.8 g/24h; p = 0.01), a lower level of serum albumin (19.3 ± 3.9 vs. 24.2 ± 8.2 g/L; p = 0.005), a higher prevalence of hematuria (70.0 vs. 38.7%; p = 0.01), and showed a lower percentage of segmental glomerulosclerosis lesion [4.8 (3.7-14.0) vs. 9.1 (5.6-21.1) %; p = 0.06]. The cumulative relapse rate was remarkably high in these patients (log-rank, p = 0.001). Multivariate analysis identified that the elevated urinary CD80 was an independent risk factor for steroid-dependent NS (OR 8.81, 95% CI 1.41-54.89; p = 0.02) and relapse (HR, 2.87; 95% CI 1.29-6.38; p = 0.01). CONCLUSIONS: The elevated urinary CD80 is associated with mild pathological change and steroid-dependent cases of primary FSGS adults, which indicates these patients are more similar to minimal change disease (MCD) in clinicopathological features.

Mild mesangial proliferative IgA nephropathy with and without minimal change disease.

Mild mesangial proliferative IgA nephropathy with minimal change disease (MCD-IgAN) and mild mesangial proliferative IgA nephropathy without minimal change disease (Non-MCD-IgAN) have similar characteristics on light microscopy. Nevertheless, their discrepancies in clinicopathological features and prognosis remain unknown. A total of 589 patients with biopsy-proven mild mesangial proliferative IgA nephropathy (M-IgAN) combined with light microscopy and immunofluorescence were enrolled. Firstly, the diagnoses of the patients by electron microscopy were recorded and used as the gold standard. We calculated the sensitivity and specificity using nephrotic syndrome (NS) as the diagnostic criteria to identify MCD-IgAN. Then, excluding patients with a 24-h urinary total protein less than 0.5 g/day, incomplete clinical data, or less than the six-month follow-up, we included 184 cases of non-MCD-IgAN and 98 cases of MCD-IgAN. The patients' clinicopathological and outcome data were collected and compared. Among the 589 patients, according to electron microscopy, 381 were diagnosed with non-MCD-IgAN, 167 with MCD-IgAN, and 41 with M-IgAN complicated by other glomerular diseases. Using NS as the diagnostic criteria to distinguish non-MCD-IgAN and MCD-IgAN, the sensitivity and specificity were 83.8% and 99.5%, respectively. The patients in the MCD-IgAN group tended to be younger, hypotensive, with lower urinary erythrocytes, and more likely to achieve complete remission, and fewer patients progressed to the endpoint than those in the non-MCD-IgAN group (all P < 0 .05). NS appears to be an objective indicator for differentiating MCD-IgAN from non-MCD-IgAN. Non-MCD-IgAN varies greatly from MCD-IgAN in clinicopathology and treatment response, with a poorer prognosis.

A Hematopoietic Stem Cell Transplant Recipient with Nephrotic Syndrome and Immune Complex Deposits in Tubular Basement Membrane: A Rare Case Report.

Following allogenic hematopoietic stem cell transplantation (HSCT), graft-versus-host disease (GVHD) may develop which may affect several organs. Although the presence of nephrotic syndrome after HSCT is rare, sometimes it occurs in the setting of GVHD. The most common histological finding on kidney biopsy of patients with proteinuria owing to GVHD is membranous glomerulonephritis (MGN). However, reports of immune complex deposition in the tubular basement membrane (TBM) and glomerular basement membrane (GBM) are extremely rare. Herein we present a 65-year-old female with a history of HSCT at six years ago who was referred to Dr.Shariati Hospital in Tehran with nephrotic syndrome. Secondary serologic laboratory tests were all normal. The histopathologic study indicated diffuse GBM and TBM thickening, spike formation, infiltration of inflammatory mononuclear cells in tubulointerstitial area and acute tubular injury in light microscopy. Immunofluorescence staining showed immune complex deposits in GBM, mesangial cells, and TBM.  DOI: 10.52547/ijkd.7550.

Membranous nephropathy.

Membranous nephropathy is a glomerulopathy, which main affected target is the podocyte, and has consequences on the glomerular basement membrane. It is more common in adults, especially over 50 years of age. The clinical presentation is nephrotic syndrome, but many cases can evolve with asymptomatic non-nephrotic proteinuria. The mechanism consists of the deposition of immune complexes in the subepithelial space of the glomerular capillary loop with subsequent activation of the complement system. Great advances in the identification of potential target antigens have occurred in the last twenty years, and the main one is the protein "M-type phospholipase-A2 receptor" (PLA2R) with the circulating anti-PLA2R antibody, which makes it possible to evaluate the activity and prognosis of this nephropathy. This route of injury corresponds to approximately 70% to 80% of cases of membranous nephropathy characterized as primary. In the last 10 years, several other potential target antigens have been identified. This review proposes to present clinical, etiopathogenic and therapeutic aspects of membranous nephropathy in a didactic manner, including cases that occur during kidney transplantation.

Nephrotic syndrome: pathophysiology and consequences.

In patients with kidney disease, nephrotic syndrome can lead to several complications including progressive kidney dysfunction. Proteinuria may lead to the formation of cellular or fibrous crescents with reciprocal development of rapidly progressive glomerulonephritis or focal glomerulosclerosis. Proteinuria may also cause overload and dysfunction of tubular epithelial cells, eventually resulting in tubular atrophy and interstitial fibrosis. Hypoalbuminemia is usually associated with increased risk of mortality and kidney dysfunction. Dyslipidemia may increase the risk of atherosclerotic complications, cause podocyte dysfunction and contribute to vascular thrombosis. Urinary loss of anticoagulants and overproduction of coagulation factors may facilitate a hypercoagulable state. Edema, hypogammaglobulinemia, loss of complement factors, and immunosuppressive therapy can favor infection. Treatment of these complications may reduce their impact on the severity of NS. Nephrotic syndrome is a kidney disorder that can worsen the quality of life and increase the risk of kidney disease progression.

Nephrotic syndrome following COVID-19 vaccination: a systematic review.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 infection has caused significant morbidity and mortality. Vaccines produced against this virus have proven highly effective. However, adverse events following vaccination have also been reported. One of them is nephrotic syndrome, that can be associated with different pathologic pictures. This review aims to provide a wider understanding of incidence, etiopathogenesis, and management of nephrotic syndrome following vaccination against SARS-CoV-2. METHODS AND RESULTS: A literature search was undertaken using appropriate keywords in various databases like PubMed, Google Scholar, Europe PMC, and Science Direct. Twenty-one articles were included following qualitative assessment. Data of 74 patients from these articles were included. DISCUSSION: The pathogenesis of nephrotic syndrome following COVID vaccination has been widely attributed to the activation of angiotensin-converting enzyme-2 receptors, leading to podocyte effacement. Relapses have also been reported in patients with prior history of nephrotic syndrome following COVID-19 vaccination. A renal biopsy is necessary to identify the histopathological picture. Management of COVID-19 vaccine-induced nephrotic syndrome was mainly reported as successfully attainable with corticosteroids and supportive management. CONCLUSION: Further investigations will help in establishing an early diagnosis and salvaging kidney function.