Glomerulopatía colapsante en un paciente con Covid-19. Reporte de caso / Collapsing glomerulonephritis in a COVID-19 patient. Case report

La injuria renal aguda por glomerulopatía colapsante, presenta alta morbimortalidad, incluso con requerimiento de diálisis crónica; la Covid-19 es una de sus causas. Se presenta el caso de un paciente con Covid-19 y glomerulopatía colapsante. Varón de 17 años, sin antecedentes patológicos; con historia de cuatro meses de edema, orina espumosa y disminución del flujo urinario. Al examen: anasarca. Exámenes: creatinina 4,2 mg/dl, albumina 1,9 gr/dl, colesterol y triglicéridos aumentados; orina: proteinuria 6,7 gr/24h, leucocituria y hematuria con urocultivo negativo. Serología para VIH, sífilis y hepatitis negativos. Inmunología para lupus negativa, prueba rápida para la Covid-19 IgG (+). La biopsia renal mostró Glomeruloesclerosis Focal y Segmentaria, variante Colapsante. Recibió corticoides y ciclosporina. La creatinina mejoró, la proteinuria se mantiene >3 gr/24horas.

SUMMARY Acute renal injury due to collapsing glomerulonephritis is associated with high morbidity and mortality, requiring chronic dialysis, COVID-19 is one of its causes. A 17-year-old male patient presented with a four-month history of edema, foamy urine and reduction in the urine flow; anasarca was observed at physical examination. Laboratory values showed creatinine 4,2 mg/dl; albumin 1,9 gr/dl; cholesterol and triglycerides were high; proteinuria 6,7 gr/24h: leucocyturia and hematuria with negative urine culture. Serologies for HIV, syphilis and hepatitis were negative. Studies for systemic lupus were negative. An antigenic test for SARS-CoV-2 was positive as well as an IgG. Renal Biopsy showed Focal and Segmental Glomerulosclerosis, Collapsing variant. He received corticosteroids and cyclosporine. Creatinine improved; proteinuria remained >3 gr/24 hours.

Genetic analysis of a child with Focal segmental glomerulosclerosis and neurodevelopmental syndrome / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic characteristics of a child with Focal segmental glomerulosclerosis and neurodevelopmental syndrome (FSGSNEDS).@*METHODS@#A child with FSGSNEDS who had visited Shengli Oilfield Central Hospital on September 15, 2019 was selected as the study subject. Clinical data of the child was collected, and trio-whole exome sequencing (trio-WES), Sanger sequencing, chromosomal karyotyping analysis, and copy number variation sequencing (CNV-seq) were used to analyze the child and his parents.@*RESULTS@#The child, a 3-year-old boy, had manifested developmental delay, nephrotic syndrome, and epilepsy. Trio-WES and Sanger sequencing showed that he has carried a heterozygous c.1375C＞T (p.Q459*) variant of the TRIM8 gene, for which both his parents were of the wild type. Based on guidelines from the American College of Medical Genetics and Genomics (ACMG), the variant was predicted to be pathogenic. No abnormality was found in the chromosomal karyotyping and CNV-seq results of the child and his parents.@*CONCLUSION@#The child was diagnosed with FSGSNEDS, for which the c.1375C＞T variant of the TRIM8 gene may be accountable.

Takayasu arteritis associated with focal and segmentary glomerulosclerosis

Takayasu arteritis (TA) is a large vessel vasculitis that affects young people, related to cardiovascular outcomes and chronic kidney disease. We present the case of a 20-year-old male with a diagnosis of TA, who developed chronic kidney disease, impaired renal blood flow was ruled out, renal biopsy was compatible with focal and segmental glomerulosclerosis of a collapsing variety, other possible aetiologies were excluded. The mechanisms that mediate this association have not been determined, immune-mediated mechanisms are proposed. According to our review, this is the second reported case of this association and the first with a collapsing variety.

La arteritis de Takayasu es una vasculitis de grandes vasos que afecta a personas jóvenes y se relaciona con desenlaces cardiovasculares y enfermedad renal crónica. Se presenta el caso de un paciente masculino de 20 arios, con diagnóstico de arteritis de Takayasu, que desarrolla enfermedad renal crónica. Se descartan alteraciones en el flujo sanguíneo renal, en tanto que la biopsia renal resulta compatible con glomeruloesclerosis focal y segmentaria de variedad colapsante. Se excluyeron otras posibles etiologías. No se han determinado los mecanismos que median en esta asociación; se proponen mecanismos inmunomediados. Según nuestra revisión, se trata del segundo caso reportado de esta asociación y el primero con variedad colapsante.

Bilateral En-Block Horseshoe Kidney Laparoscopic Nephrectomy / Nefrectomía bilateral en bloque en riñón en herradura

Horseshoe kidney (HSK) has a prevalence of 1 in every 500 individuals. The management of patients with HSK is usually conservative, except in the presence of symptoms such as obstruction, stones, glomerulopathies, and tumors. In the following case report, we describe how a bilateral en-block transmesenteric laparoscopic nephrectomy in supine position was performed. A 5-year-old boy, with proximal hypospadias and early onset of chronic kidney disease due to focal segmental glomerulosclerosis on biopsy, underwent a genetic molecular evaluation that confirmed a pathogenic mutation at the WT-1 gene. Due to the increased risk of developing Wilms tumor, he underwent a bilateral transmesenteric nephrectomy. In a five-minute video, we describe how we performed an en-block transperitoneal and transmesenteric laparoscopic nephrectomy with special attention to patient positioning, including the feasibility of performing the dissection of the left renal hilum and isthmus with the patient in supine with no need for repositioning, and then moving to the dissection of the right renal hilum and completion of the procedure. The case herein reported enables us to describe the technical key-points to perform a bilateral en-block laparoscopic nephrectomy with shorter operative time and reduction of blood loss by preserving the entire specimen, without the need for an isthmus transection.

El riñón en herradura (RH) tiene una prevalencia de 1 en cada 500 individuos. El manejo del RH es usualmente conservador, excepto cuando genera síntomas como obstrucción, litiasis, glomerulopatías o tumores. Con este reporte de caso, describimos como se realizó una nefrectomia bilateral en bloque transmesentérica en un paciente con riñón en herradura. Un paciente de 5 años de edad, con hypospadias proximal y desarrollo temprano de enfermedad renal crónica por glomeruloesclerosis focal segmentaria, fue sometido a un estudio molecular que confirmó la presencia de una mutación en el gen WT-1. Dado el alto riesgo de desarrollar tumor de Wilms, se decidió realizar una nefrectomía transperitoneal laparoscópica bilateral. En un video de cinco minutos, describimos como se realizó una nefrectomía transperitoneal y transmesentérica en bloque, con especial atención al posicionamiento del paciente, incluso la viabilidad de realizar la disección del hilio renal izquierdo y el istmo con el paciente en supino, sin necesidad de reposicionarlo, y, después, la disección del hilio renal derecho y el fin del procedimiento. El caso reportado nos permite describir los puntos clave técnicos para realizar una nefrectomía laparoscópica bilateral en bloque con un tiempo operativo más corto y reducción del sangrado al preservar todo el espécimen, sin la necesidad de realizar la transección del istmo.

Association of karyomegalic interstitial nephritis with focal segmental glomerulosclerosis

Karyomegalic interstitial nephritis (KIN), first described in 1974, is a rare form of chronic tubulointerstitial nephritis. It is defined by the presence of markedly enlarged, hyperchromatic nuclei with prominent nucleoli, mainly involving tubular epithelial cells of the kidney, accompanied by marked interstitial fibrosis. The disease presents as asymptomatic proteinuria, gradually progresses to chronic kidney disease and eventually leads to end-stage renal disease by 30-40 years. The etiology of the disease remains unclear; however, genetic risk factors and possible association with HLA (B27/35) is proposed by some. It has also been linked to FAN1 (FANCD2/FANC1- associated nuclease 1) mutation. Case Report We present two cases of KIN with associated focal segmental glomerulosclerosis. Both patients presented with nephrotic range proteinuria. The biopsies demonstrated marked enlargement of tubular nuclei (3-5x larger than the uninvolved tubular nuclei, a metric used by some authors in previous studies) in some tubules, meeting the diagnostic criteria of KIN.. Interestingly, case one had a prior biopsy that showed minimal change disease. In the biopsies done at our institution, H&E sections showed patchy tubular attenuation with readily recognizable tubular cell mitotic figures, indicating concurrent acute tubular injury. Electron microscopy showed diffuse podocyte foot process effacement, along with microvillous transformation, podocyte hypertrophy, and cytoplasmic vacuoles, suggesting podocyte injury. This cytoplasmic vacuolization was also observed in the tubular epithelial cells. In both cases, the injury factor appeared to target both podocytes and tubular cells.

Collapsing focal segmental glomerulosclerosis probably triggered by dengue virus infection - two case reports / Glomeruloesclerose Segmentar e Focal Colapsante provavelmente desencadeada por infecção pelo vírus da dengue - dois relatos de caso

Abstract The reported cases describe the association between collapsing focal segmental glomerulosclerosis (FSGS) and acute dengue virus infection. In both cases, patients were diagnosed with dengue virus infection and had a severe kidney disease, with nephrotic syndrome and acute kidney injury. Kidney biopsy was performed and showed collapsing FSGS. The first patient, a 27-year-old man, was diagnosed with dengue virus infection and developed nephrotic syndrome after two weeks of illness. He was treated with methylprednisolone for three days and intravenous furosemide. This patient evolved well, although his renal function did not fully recover. The second patient, a 32-year-old man, was diagnosed with a milder clinical presentation of dengue virus infection. He had a past medical history of nephrotic syndrome in childhood, which might have caused its relapse. This patient was treated with intravenous furosemide and also did not fully recover renal function. These cases highlight the possible implication of dengue virus infection in the etiology of collapsing variant of FSGS. Healthcare professionals should be prepared to identify similar cases.

Resumo Os casos relatados descrevem a associação entre glomeruloesclerose segmentar e focal (GESF) colapsante e infecção aguda pelo vírus da dengue. Nas duas instâncias os pacientes foram diagnosticados com infecção pelo vírus da dengue e apresentaram doença renal grave, com síndrome nefrótica e insuficiência renal aguda. A biópsia renal revelou a presença de GESF colapsante. O primeiro paciente, um homem de 27 anos, foi diagnosticado com infecção pelo vírus da dengue e desenvolveu síndrome nefrótica após duas semanas de doença. Ele foi tratado com metilprednisolona por três dias e furosemida endovenosa. O paciente evoluiu bem, embora sua função renal não tenha se recuperado plenamente. O segundo paciente, um homem de 32 anos, foi diagnosticado com apresentação clínica mais discreta de infecção pelo vírus da dengue. Ele tinha histórico de síndrome nefrótica na infância, o que pode ter causado a recidiva. O paciente foi tratado com furosemida endovenosa e também não recuperou plenamente sua função renal. Os dois casos destacam a possível implicação da infecção pelo vírus da dengue na etiologia da variante colapsante da GESF. Os profissionais de saúde devem estar preparados para identificar casos semelhantes.

Focal and Segmental Glomerulosclerosis and Membranous Nephropathy overlapping in a patient with Nephrotic Syndrome: a case report / Glomeruloesclerose Segmentar e Focal e Nefropatia Membranosa sobrepostas em paciente com Síndrome Nefrótica: relato de caso

Abstract Introduction: Some cases of membranous nephropathy (MGN) present focal segmental glomerulosclerosis (FSGS) typically associated with disease progression. However, we report a case of a patient who seemed to have MGN and FSGS, both primary. Case presentation: A 17-year-old female, Caucasian, presenting lower extremity edema associated with episodes of foamy urine and high blood pressure, had physical and laboratorial exams indicating nephrotic syndrome. A renal biopsy was performed and focal and segmental glomerulosclerosis were observed under light microscopy in some glomeruli presented as tip lesion, and in others it was accompanied by podocyte hypertrophy and podocyte detachment in urinary space, compatible with podocytopathy FSGS. Besides, there were thickened capillary loops with basement membrane irregularities due to "spikes" compatible with MGN stage II. Immunofluorescence showed finely granular IgG, IgG4, and PLA2R deposits in capillary loops and, in electron microscopy, subepithelial deposits and foot process effacement. These morphological findings are compatible with FSGS and MGN stage II. Conclusions: In the present case, clinical and morphological characteristics showed a possible overlap of primary FSGS and MGN as focal and segmental glomerulosclerosis does not seem to be related with MGN progression but with the podocytopathy FSGS.

Resumo Introdução: Alguns casos de nefropatia membranosa (NM) apresentam glomeruloesclerose segmentar e focal (GESF) tipicamente associada a progressão da doença. Contudo, relatamos o caso de uma paciente que parece ter NM e GESF, ambas primárias. Apresentação do caso: Uma jovem branca de 17 anos de idade com edema de membros inferiores associado a episódios de urina espumosa e hipertensão apresentou-se com achados físicos e laboratoriais sugestivos de síndrome nefrótica. Foi realizada biópsia renal. GESF foi observada por microscopia de luz em alguns glomérulos que apresentavam lesões de ponta, enquanto em outros o achado era acompanhado por hipertrofia podocitária e descolamento de podócitos no espaço urinário, compatíveis com podocitopatia GESF. Além disso, as alças capilares estavam espessadas com irregularidades na membrana basal devido a "espículas" compatíveis com NM estágio II. Imunofluorescência revelou depósitos finamente granulares de IgG, IgG4 e PLA2R nas alças capilares. Microscopia eletrônica exibiu depósitos subepiteliais e apagamento de pedicelos. Tais achados morfológicos são compatíveis com GESF e NM estágio II. Conclusões: No presente caso, as características clínicas e morfológicas revelaram uma possível sobreposição de GESF primária e NM, uma vez que a glomeruloesclerose segmentar e focal não parece estar relacionada com a progressão da NM, mas com a podocitopatia GESF.

Unexpectedly High Prevalence of Low Alpha-Galactosidase A Enzyme Activity in Patients with Focal Segmental Glomerulosclerosis

OBJECTIVES: Fabry disease (FD) is a rare disease associated with sphingolipid accumulation. Sphingolipids are components of plasma membranes that are important in podocyte function and accumulate in various glomerular diseases such as focal segmental glomerulosclerosis (FSGS). Both FD and FSGS can cause podocyte damage and are classified as podocytopathies. In this respect, FD and FSGS share the same pathophysiologic pathways. Previous screening studies have shown that a significant proportion of end-stage renal disease (ESRD) patients receiving hemodialysis (HD) have unsuspected FD, and the prevalence of low alpha-galactosidase A (αGLA) enzyme activity in these patients is higher than that in the normal population. We aimed to compare αGLA enzyme activity in patients with biopsy-proven FSGS and ESRD receiving HD. METHODS: The records of 232 patients [62 FSGS (F/M: 33/29); 170 HD (M/F: 93/79)] were evaluated retrospectively. The screening was performed based on the αGLA enzyme activity on a dried blood spot, with the confirmation of plasma LysoGb3 levels, and the known GLA mutations were tested in patients with low enzyme activities. The two groups were compared using these parameters. RESULTS: The mean level of αGLA enzyme activity was found to be lower in FSGS patients than in the HD group (2.88±1.2 μmol/L/h versus 3.79±1.9 μmol/L/h, p<0.001). There was no significant relationship between the two groups with regard to the plasma LysoGb3 levels (2.2±1.22 ng/ml versus 1.7±0.66 ng/ml, p: 0.4). In the analysis of GLA mutations, a D313Y mutation [C(937G>T) in exon p] was found in one patient from the FSGS group. CONCLUSIONS: We found that αGAL activity in patients with FSGS is lower than that in patients undergoing HD. The low enzyme activity in patients with FSGS may be explained by considering the similar pathogenesis of FSGS and FD, which may also lead to sphingolipid deposition and podocyte injury.

Basic fibroblast growth factors as a biomarker of focal segmental glomerulosclerosis in HIV-positive and HIV-negative children

Background. HIV infection can lead to the development of HIV-associated nephropathy (HIVAN) with the majority of patients progressing to end-stage kidney disease. Previous studies have recognised basic fibroblast growth factor (bFGF) as a biomarker for HIVAN, since significant levels of bFGF low-affinity receptors have been found in the kidneys of HIV-infected children.Objective. To assess the association between bFGF and kidney disease in the development of focal segmental glomerulosclerosis (FSGS) in HIV-positive and negative children.Methods. The study group consisted of 31 children; HIVAN (n=11) and idiopathic FSGS (n=20). The control group consisted of both HIV-positive (n=20) and HIV-negative (n=20) children with no kidney disease. Serum samples from all patients in both the study and control groups were analysed for bFGF.Results. The concentration of bFGF was higher, in comparison with idiopathic FSGS children, in HIVAN children (p=0.0167). There was also a significant elevation of serum bFGF levels in children with HIVAN when compared with HIV-positive (p=0.0288) and HIV-negative (p=0.0043) control groups.Conclusion. This study demonstrated statistically significant differences between bFGF levels in children with HIVAN and a control group, although it failed to distinguish significant differences in bFGF levels between HIVAN and idiopathic FSGS children

Una nueva variante del gen COL4A4 (c.1856G> A). De un caso de glomeruloesclerosis focal y segmentaria a una familia con síndrome de Alport / A novel COL4A4 gene variant (c.1856G>A): from a focal segmental glomerulosclerosis case to a family with Alport syndrome

El síndrome de Alport (SA), también conocido como nefritis hereditaria, es una forma progresiva hereditaria de enfermedad glomerular que a menudo se asocia con pérdida auditiva neurosensorial y anomalías oculares. Es causada por mutaciones en los genes que codifican varios miembros de las proteínas de colágeno del tipo IV, que se hallan en las membranas basales principalmente. Los análisis genéticos de las familias afectadas han identificado cuatro modos diferentes de transmisión en pacientes con síndrome de Alport. La forma del síndrome ligada al X surge a partir de mutaciones de COL4A5 y COL4A6 en el cromosoma X, mientras que las formas autosómicas resutan de defectos genéticos tanto en el gen COL4A3 como en el COL4A4, en el cromosoma 2q35-37. Las formas digénicas incluyen pacientes con mutaciones coexistentes en COL4A3, COL4A4 y COL4A5. El resultado clínico a largo plazo en pacientes con SA con mutaciones heterocigotas de COL4A3/A4es generalmente impredecible. La glomeruloesclerosis focal y segmentaria suele desarrollarse en el SA clásico en etapas posteriores y se presenta predominantemente con proteinuria asociada con hematuria. En el caso índice presentado en este informe, a un hombre de 26 años se le realizó una biopsia de riñón debido a una proteinuria nefrótica y una hematuria microscópica acompañada de una función renal alterada. Se le diagnosticó glomeruloesclerosis focal y segmentaria. Debido a que tenía una pérdida auditiva progresiva desde el inicio del estudio, se le realizó un estudio genético de mutaciones en los genes COL4A3 y COL4A4. Se detectó una nueva mutación en el gen COL4A4 (c.1804-7T> C).Debido a que sus padres tenían un matrimonio consanguíneo, el resto de la familia fue sometida a estudio para la misma variante. Sus padres y su hermana fueron heterocigotos y homocigota para la misma variante, respectivamente. En este estudio, se demostró la existencia de una familia con síndrome de Alport con una nueva mutación en el gen COL4A4 (c.1856G> A) que, según sabemos, es el primer caso reportado.

Alport syndrome, also known as hereditary nephritis, is an inherited progressive form of glomerular disease that is often associated with sensorineural hearing loss and ocular abnormalities. It is caused by mutations in genes encoding several members of type IV colagen proteins primarily found in basement membranes. Genetic analyses of affected families have identified four different modes of transmission in patients with Alport syndrome. X-linked form of the syndrome arises from mutations of COL4A5 and COL4A6 on chromosome X, whereas autosomal forms result from genetic defects in either the COL4A3 or COL4A4 genes at chromosome 2q35-37. Digenic forms include patients with coexisting mutations in COL4A3, COL4A4, and COL4A5. The long-term clinical outcome in AS patients with heterozygous COL4A3/A4 mutations is generally unpredictable. Focal segmental glomerulosclerosis usually develops in classical AS at later stages and presents predominantly with proteinuria associated with hematuria. The index case presented in this report, a 26-year-old man, had kidney biopsy because of nephrotic proteinuria and microscopic hematuria accompanied by impaired renal function. He diagnosed focal segmental glomerulosclerosis. As he had progressive hearing loss since chidhood we conducted a genetic study for mutations in COL4A3 and COL4A4 genes. A novel mutation in COL4A4 gene (c.1804-7T>C) was detected. As his parents had consanguineous marriage we investigated the rest of the family for the same variant. His parents, and his sister were found to be heterozygote, and homozygote for the same variant, respectively. In this report we demonstrated an Alport syndrome family with a novel mutation in COL4A4 gene (c.1856G>A) that has been first reported to our best knowledge.

The metabolomics signature associated with responsiveness to steroid therapy in focal segmental glomerulosclerosis: a pilot study

Abstract Background Focal segmental glomerulosclerosis (FSGS) is considered one of the most severe glomerular diseases and around 80% of cases are resistant to steroid treatment. Since a large proportion of steroid-resistant (SR) FSGS patients progress to end-stage renal disease, other therapeutic strategies may benefit this population. However, identification of non-invasive biomarkers to predict this high-risk population is needed. Objective We aimed to identify the biomarker candidates to distinguish SR from steroid-sensitive (SS) patients using metabolomics approach and to identify the possible molecular mechanism of resistance. Methods Urine was collected from biopsy-proven FSGS patients eligible for monotherapy with prednisolone. Patients were followed for 6-8 weeks and categorized as SS or SR. Metabolite profile of urine samples was analyzed by one-dimensional 1H-nuclear magnetic resonance (1H-NMR). Predictive biomarker candidates and their diagnostic importance impaired molecular pathways in SR patients, and the common target molecules between biomarker candidates and drug were predicted. Results Homovanillic acid, 4-methylcatechol, and tyrosine were suggested as the significant predictive biomarker candidates, while L-3,4-dihydroxyphenylalanine, norepinephrine, and gentisic acid had high accuracy as well. Tyrosine metabolism was the most important pathway that is perturbed in SR patients. Common targets of the action of biomarker candidates and prednisolone were molecules that contributed in apoptosis. Conclusion Urine metabolites including homovanillic acid, 4-methylcatechol, and tyrosine may serve as potential non-invasive predictive biomarkers for evaluating the responsiveness of FSGS patients.

Obesidad y riñón / Obesity and the kidney

RESUMEN Introducción: La obesidad es un problema de salud mundial y su frecuencia se está incrementando tanto en adultos como en niños. Una de sus complicaciones es la glomerulopatía asociada a la obesidad. Objetivo: Informar acerca de esta enfermedad y la actitud del pediatra para tratar de evitarla. Métodos: Revisión de la literatura médica más reciente sobre la enfermedad y el incremento de la obesidad en la edad pediátrica en las bases de datos PubMed, SciELO y LILACS. Se utilizaron las palabras clave: glomerulopatía relacionada con la obesidad, obesidad y sobrepeso en el niño, tratamiento de la obesidad. Resultados: La obesidad en el niño es en alto porcentaje de causa nutricional y en esta condición los factores ambientales y socioculturales juegan importante papel. La predisposición a padecer la glomerulopatía de la obesidad comienza desde la niñez. El tratamiento de los pediatras en estos casos estará dirigido a la prevención de la enfermedad puesto que se puede desarrollar en la adultez. Cuando fracasan las medidas preventivas, queda la posibilidad de la cirugía bariátrica con poca experiencia en la edad pediátrica y retos éticos importantes y a pesar de que pudiera ser una alternativa de tratamiento, no es aceptada hasta el presente en forma amplia. Conclusiones: La glomerulopatía de la obesidad, por lo general, no aparece hasta la adultez, pero es necesario prevenirla desde la edad pediátrica y para su prevención los pediatras deben estar atentos a los factores de riesgo que pueden aparecer desde las primeras etapas de la vida(AU)

ABSTRACT Introduction: Obesity is a global health problem and its frequency is increasing as much as in adults than in children. One of its complications is glomerulopathy associated to obesity. Objective: To inform on this disease and the attitude of pediatricians towards this trying to avoid it. Methods: Reviewing of the most recent medical literature on this disease and the increase of obesity in the pediatric age in PubMed, SCIELO and LILACS databases. The keywords used for the search were: glomerulopathy related to obesity, obesity and overweight in children, and obesity treatment. Results: Obesity in children is in a high percentage due to nutritional causes and in this disease environmental and sociocultural factors play an important role. The predisposition to suffer from glomerulopathy by obesity starts in childhood. The treatment prepared by the pediatricians in these cases will be directed to the prevention of the disease because it can be developed in adulthood. When preventive measures fail, there is the possibility of performing a bariatric surgery, having in this regard few experiences in the pediatric ages and important ethical challenges; and instead of being an alternative treatment, it is not widely accepted. Conclusions: Generally, glomerulopathy of obesity doesn't appear until adulthood, but it is necessary to prevent it since the pediatric age; and for its prevention pediatricians must be attentive to the risk factors that can appear from the earliest stages of life(AU)

Circulating Permeability Factors in Idiopathic Nephrotic Syndrome

Nephrotic syndrome (NS) is a common chronic glomerular disease in children characterized by significant proteinuria with resulting hypoalbuminemia, edema, and hyperlipidemia. Renal biopsy findings of diffuse foot processes effacement on electron microscopy and minimal change disease, focal segmental glomerulosclerosis (FSGS), or diffuse mesangial proliferation on light microscopy. It has been speculated that circulating permeability factors would be implicated in the pathogenesis of NS because they have been reportedly detected in the sera of patients and in experimental models of induced proteinuria. Moreover, a substantial portion of the patients with primary FSGS recurrence shortly after transplantation. This report reviews the current knowledge regarding the role of circulating permeability factors in the pathogenesis of proteinuria in NS and suggests future targeted therapeutic approaches for NS.

Renal tubular P-glycoprotein expression is reduced in plasma cell disorders

BACKGROUND: P-glycoprotein (P-gp) transports many chemicals that vary greatly in their structure and function. It is normally expressed in renal proximal tubular cells. We hypothesized that P-gp expression influences light chain excretion. Therefore, we investigated whether renal tubular P-gp expression is altered in patients with plasma cell disorders. METHODS: We evaluated renal biopsy specimens from patients with plasma cell disorders (n = 16) and primary focal segmental glomerulosclerosis (the control group, n = 17). Biopsies were stained with an anti-P-gp antibody. Loss of P-gp expression was determined semi-quantitatively. Groups were compared for loss of P-gp expression, and clinical variables. RESULTS: P-gp expression loss was more severe in patients with plasma cell disorders than it was in those with glomerulonephritis (P = 0.021). In contrast, clinical and histological parameters including serum creatinine, level of urinary protein excretion, and interstitial fibrosis/tubular atrophy grade were not significantly different between the groups. P-gp expression loss increased with age in patients with plasma cell disorders (P = 0.071). This expression loss was not associated with serum creatinine, the level of urinary protein excretion or the interstitial fibrosis/tubular atrophy grade. There was no significant association between the severity of P-gp expression loss with the types and serum levels of light chains, isotypes and serum immunoglobulin levels. CONCLUSION: Renal tubular P-gp expression is significantly down-regulated in patients with plasma cell disorders characterized by nephrotic range proteinuria. Additional studies are needed to determine whether reintroduction of renal tubular P-gp expression would mitigate the proximal tubular injury that is caused by free-light chains.

Analysis of a pedigree with autosomal dominant intermediate Charcot-Marie-Tooth disease type E and nephropathy / 中华医学遗传学杂志

OBJECTIVE@#To explore phenotypic and mutational characteristics of a pedigree affected with autosomal dominant Charcot-Marie-Tooth disease (CMT) and nephropathy.@*METHODS@#Clinical data of the proband and his family members was collected. Electrophysiology, renal biopsy and next-generation sequencing were carried out for the proband.@*RESULTS@#The proband presented with distal lower limb weakness and proteinuria in childhood. His mother and brother had similar symptoms. Electrophysiological test of the proband revealed demyelination and axonal changes in both motor and sensory nerves. Renal biopsy suggested focal segmental glomerulosclerosis. Genetic testing revealed a heterozygous c.341G>A (p.G114D) mutation in exon 2 of the INF2 gene.@*CONCLUSION@#The phenotypic feature of the pedigree is autosomal dominant intermediate CMT and focal segmental glomerulosclerosis, which may be attributed to the c.341G>A mutation of the INF2 gene.

Advances in research on gene and cell therapy for type IV collagen related hereditary kidney diseases / 中华医学遗传学杂志

Type IV collagen is a component of the extracellular matrix in the basement membrane. Abnormal secretion or assembly of type IV collagen may lead to kidney lesions resulting in numerous nephropathy symptoms, e.g., Alport syndrome, thin basement membrane nephropathy, and focal segmental glomerulosclerosis. Treatment for type IV collagen-related nephropathy includes drugs, kidney transplantation, gene and cell therapy. However, drugs are not always effective, and kidney transplantation is hindered by the shortage of donors. Moreover, basement membrane nephritis often occurs after kidney transplantation. Therefore, gene and cell therapy probably is the most promising treatment for type IV collagen related nephropathies.

Two Cases of Hypersensitivity Reactions Caused by Human Serum Albumin During Therapeutic Plasma Exchange

Iso-oncotic human serum albumin (HSA) is the primary replacement fluid of choice during therapeutic plasma exchange (TPE). Hypersensitivity reactions to HSA are rare, but require proper evaluation and management. In this article, we report two cases of hypersensitivity reactions to 5% HSA during TPE and discuss strategies to address this problem. The first case was a 60-year-old female patient, who was scheduled for TPE for treatment of recurrent focal segmental glomerulosclerosis after ABO-incompatible kidney transplantation. She developed a pruritic rash on her entire body during the first two sessions of TPE using 5% HSA. The third session was conducted using 500 mL normal saline, 1,000 mL 10% pentastarch, and 750 mL 5% HSA, where she eventually developed a pruritic rash when HSA was infused. There were no adverse events during the fourth and fifth session when fresh frozen plasma was used in place of HSA. The second case was a 50-year-old male patient diagnosed with optic neuritis, who was admitted for five sessions of TPE. The patient developed a pruritic rash on his entire body during the first session of TPE using 5% HSA. The patient experienced no adverse events during the following four sessions using fresh frozen plasma. Certain elements contained in HSA, such as albumin aggregates, prekallikrein activator, and caprylate-modified albumin, might be the reason for these hypersensitivity reactions. Careful selection of alternative replacement fluids is important to avoid premature termination of TPE procedures and secure optimal treatment options for patients.

Daño hepatocelular, proteinuria y autoinmunidad: ¿enfermedad multisistémica o coincidencia de enfermedades? Caso clínico / Hepatocellular damage, proteinuria and autoimmunity: multisystemic disorder or coexistence of diseases?

We report a 19 years old male presenting with knee pain, elevated liver enzymes and proteinuria. Further investigation found positive antinuclear and anti-smooth muscle antibodies and a liver biopsy revealed the presence of an autoimmune hepatitis. Treatment with corticosteroids and azathioprine was started, resulting in normalization of liver enzymes but proteinuria persisted and a kidney biopsy disclosed a focal segmental glomerulosclerosis. The use of lisinopril resulted in a significative reduction of proteinuria and, after 30 months of follow up, he continues with azathioprine, lisinopril and a low prednisone dose without evidence of liver or kidney disease activity.

Obesidade e doença renal: aspectos fisiopatológicos / Obesity and kidney disease: pathophysiological aspects

A epidemia de obesidade observada nas últimas décadas é acompanhada de aumento exponencial de doenças crônicas relacionadas, com destaque diabetes mellitus tipo 2, hipertensão arterial sistêmica, dislipidemia e doenças cardiovasculares. Do mesmo modo, a obesidade constitui fator de risco independente para o desenvolvimento de doença renal crônica, condição associada a elevados índices de morbidade e de mortalidade. A obesidade causa lesão renal de maneira indireta, por meio de sua estreita associação com hipertensão arterial sistêmica e com diabetes mellitus tipo 2 e de maneira direta, ao induzir adaptações glomerulares que culminam na glomerulopatia específica da obesidade. Além disso, o excesso de peso contribui para o agravamento de glomerulopatias pré-existentes. Múltiplos fatores explicam o desenvolvimento e o agravamento das lesões renais associadas à obesidade, em especial alterações hemodinâmicas, inflamatórias e metabólicas. Nesse contexto, a redução do peso corporal com ênfase nas alterações metabólicas e inflamatórias bem como o tratamento da hipertensão arterial e do diabetes mellitus constituem o primeiro passo para a prevenção primária e secundária do desenvolvimento de doença renal crônica. Nesta revisão serão apresentados os principais mecanismos fisiopatológicos da lesão renal associada à obesidade.

n the last decades, the obese epidemic has been accompanied by an exponential increase in the prevalence of chronic conditions such as type 2 diabetes, hypertension, dyslipidemia, and other forms of cardiovascular disease. Moreover, obesity is an independent risk factor for the development of chronic kidney disease, itself a condition associated with high risk of morbidity and mortality. Obesity can cause chronic kidney disease both indirectly, as a major risk factor for diabetes and hypertension, and directly, through adaptive glomerular changes that evolve into a specific form of glomerulopathy. Furthermore, excessive weight can worsen other forms of pre-existent glomerular diseases. Multiple factors can explain the development and worsening of renal lesions associated with obesity, mainly through hemodynamic, inflammatory and metabolic changes. In this context, reduction of body weight with emphasis on metabolic and inflammatory changes, as well as the treatment of hypertension and diabetes, constitute the first step towards primary and secondary prevention against development of chronic kidney disease. This review presents the physiopathology of the obesity related glomerulopathy.

New Mutation of Coenzyme Q Monooxygenase 6 Causing Podocyte Injury in a Focal Segmental Glomerulosclerosis Patient / 中华医学杂志(英文版)

Background@#Focal segmental glomerulosclerosis (FSGS) is a kidney disease that is commonly associated with proteinuria and the progressive loss of renal function, which is characterized by podocyte injury and the depletion and collapse of glomerular capillary segments. The pathogenesis of FSGS has not been completely elucidated; however, recent advances in molecular genetics have provided increasing evidence that podocyte structural and functional disruption is central to FSGS pathogenesis. Here, we identified a patient with FSGS and aimed to characterize the pathogenic gene and verify its mechanism.@*Methods@#Using next-generation sequencing and Sanger sequencing, we screened the causative gene that was linked to FSGS in this study. The patient's total blood RNA was extracted to validate the messenger RNA (mRNA) expression of coenzyme Q monooxygenase 6 (COQ6) and validated it by immunohistochemistry. COQ6 knockdown in podocytes was performed in vitro with small interfering RNA, and then, F-actin was determined using immunofluorescence staining. Cell apoptosis was evaluated by flow cytometry, the expression of active caspase-3 was determined by Western blot, and mitochondrial function was detected by MitoSOX.@*Results@#Using whole-exome sequencing and Sanger sequencing, we screened a new causative gene, COQ6, NM_182480: exon1: c.G41A: p.W14X. The mRNA expression of COQ6 in the proband showed decreased. Moreover, the expression of COQ6, which was validated by immunohistochemistry, also had the same change in the proband. Finally, we focused on the COQ6 gene to clarify the mechanism of podocyte injury. Flow cytometry showed significantly increased in apoptotic podocytes, and Western blotting showed increases in active caspase-3 in si-COQ6 podocytes. Meanwhile, reactive oxygen species (ROS) levels were increased and F-actin immunofluorescence was irregularly distributed in the si-COQ6 group.@*Conclusions@#This study reported a possible mechanism for FSGS and suggested that a new mutation in COQ6, which could cause respiratory chain defect, increase the generation of ROS, destroy the podocyte cytoskeleton, and induce apoptosis. It provides basic theoretical basis for the screening of FSGS in the future.