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Theophilus UI, John JR, Ihab S, Ahmed H. Recurrent Focal Segmental Glomerulosclerosis After Kidney Transplantation in African Americans: Review of the Current Evidence. EXP CLIN TRANSPLANT 2021; 19:1245-1256. [PMID: 34269655 DOI: 10.6002/ect.2020.0542] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
OBJECTIVES In many countries of sub-Saharan Africa, the most common causes of end-stage kidney disease are hypertension, chronic glomerulonephritis, and diabetes mellitus. So far, literature on recurrent focal segmental glomerulosclerosis in sub-Saharan African populations is limited. With the intention of providing guidance for best practices in sub-Saharan Africa, we reviewed available evidence for African Americans, a population with a similar genetic background. We chose this population as a pseudo-population to show how similar genetic backgrounds can predict disease occurrence in similar populations residing in different continents. MATERIALS AND METHODS Our extended PubMed and Scopus literature search used these key words: "focal segmental glomerulosclerosis in African Americans" (search 1), "recurrent focal segmental glomerulosclerosis after kidney transplantation" (search 2), "risk factors for recurrent focal segmental glomerulosclerosis" (search 3); and "APOL1 gene and kidney transplantation" (search 4). RESULTS/CONCLUSIONS Search 1 yielded 4 articles, search 2 yielded 44 articles, search 3 yielded 6 articles, and search 4 yielded 8 articles. African Americans were shown to be disproportionately predisposed to endstage kidney disease, traceable to focal segmental glomerulosclerosis (the most common cause of glomerulonephritis leading to end-stage kidney disease). Apolipoprotein L1 presence in 22% of African Americans explained the odds ratio of 17 in developing focal segmental glomerulosclerosis and 8 times lifetime risk of end-stage kidney disease. Focal segmental glomerulosclerosis recurred in 30% of kidney transplant recipients; risk factors included young age, rapid progression to end-stage kidney disease, and White race recipient. Circulating permeability factors played a central role in primary and recurrent focal segmental glomerulosclerosis. For recurrent cases, transplant biopsy has remained the gold standard for diagnosis, with treatment involving a multi-modal approach, often resulting in partial or complete remission of proteinuria; allograft loss can occur if treatment is not successful. More randomized clinical trials are needed to chart the way forward for prolonged allograft function.
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Affiliation(s)
- Umeizudike I Theophilus
- From the Department of Medicine, Lagos State University Teaching Hospital, Ikeja, Lagos State, Nigeria
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Intrinsic tumor necrosis factor-α pathway is activated in a subset of patients with focal segmental glomerulosclerosis. PLoS One 2019; 14:e0216426. [PMID: 31095586 PMCID: PMC6522053 DOI: 10.1371/journal.pone.0216426] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Accepted: 04/20/2019] [Indexed: 01/09/2023] Open
Abstract
Focal segmental glomerulosclerosis (FSGS) is frequently found in biopsies of patients with steroid resistant nephrotic syndrome (SRNS). The pathogenesis of SRNS/FSGS is often unknown and the disease will recur in up to 50% of patients post-transplant, indicating the presence of circulating podocyte-toxic factor(s). Several studies have reported clinical improvement after anti-TNFα therapy. However, prediction of the clinical outcome in SRNS/FSGS is difficult, and novel predictive biomarkers are needed. An image-based assay, which measures disassembly of focal adhesion complexes in cultured podocytes, was used to ascertain the presence of podocyte toxic activity in SRNS/FSGS sera. Expression of TNFα pathway genes was analysed in the Nephroseq FSGS cohort and in cultured podocytes treated with SRNS/FSGS sera. Podocyte toxic activity was detected in 48/96 SRNS/FSGS patients. It did not correlate with serum TNFα levels, age, sex, ethnicity or glomerular filtration rate. In ~25% of the toxic samples, the toxicity was strongly inhibited by blockade of TNFα signaling. Transcriptional profiling of human FSGS biopsies and podocytes treated with FSGS sera revealed significant increases in expression of TNFα pathway genes. We identified patients with serum podocyte toxic activity who may be at risk for FSGS recurrence, and those patients in whom serum podocyte toxicity may be reversed by TNFα blockade. Activation of TNFα pathway genes occurs in podocytes of FSGS patients suggesting a causative effect of this pathway in response to circulating factor(s). In vitro analyses of patient sera may stratify patients according to prognostic outcomes and potential responses to specific clinical interventions.
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Use of genomic and functional analysis to characterize patients with steroid-resistant nephrotic syndrome. Pediatr Nephrol 2018; 33:1741-1750. [PMID: 29982877 DOI: 10.1007/s00467-018-3995-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Revised: 06/06/2018] [Accepted: 06/07/2018] [Indexed: 01/09/2023]
Abstract
BACKGROUND Children with genetic causes of steroid-resistant nephrotic syndrome (SRNS) usually do well after renal transplantation, while some with idiopathic SRNS show recurrence due to a putative podocyte-toxic factor. Distinguishing different forms of SRNS based on clinical criteria has been difficult. The aim of our study was to test a novel approach that allows categorization of patients into clinically useful subgroups. METHODS Seventeen patients with clinically confirmed SRNS were analyzed by next-generation sequencing (NGS) of 37 known SRNS genes and a functional assay of cultured human podocytes, which indirectly tests for toxicity of patients' sera by evidenced loss of podocyte focal adhesion complex (FAC) number. RESULTS We identified a pathogenic mutation in seven patients (41%). Sera from patients with monogenic SRNS caused mild loss of FAC number down to 73% compared to untreated controls, while sera from seven of the remaining ten patients with idiopathic SRNS caused significant FAC number loss to 43% (non-overlapping difference 30%, 95% CI 26-36%, P < 0.001). All patients with recurrent SRNS (n = 4) in the graft showed absence of podocyte gene mutations but significant FAC loss. Three patients had no mutation nor serum podocyte toxicity. CONCLUSIONS Our approach allowed categorization of patients into three subgroups: (1) patients with monogenic SRNS; (2) patients with idiopathic SRNS and marked serum podocyte toxicity; and (3) patients without identifiable genetic cause nor evidence of serum podocyte toxicity. Post-transplant SRNS recurrence risk appears to be low in groups 1 and 3, but high in group 2.
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Kachurina N, Chung CF, Benderoff E, Babayeva S, Bitzan M, Goodyer P, Kitzler T, Matar D, Cybulsky AV, Alachkar N, Torban E. Novel unbiased assay for circulating podocyte-toxic factors associated with recurrent focal segmental glomerulosclerosis. Am J Physiol Renal Physiol 2015; 310:F1148-56. [PMID: 26719363 DOI: 10.1152/ajprenal.00349.2015] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Accepted: 12/28/2015] [Indexed: 01/28/2023] Open
Abstract
Focal segmental glomerular sclerosis (FSGS) is an irreversible renal pathology characterized by podocyte detachment from the glomerular basement membrane, hyalinosis, and sclerosis. Clinically, it manifests with proteinuria and progressive loss of glomerular filtration. Primary idiopathic FSGS can occur in isolation and frequently progresses to end-stage renal disease, requiring dialysis or kidney transplantation. In 30-50% of these patients, proteinuria and FSGS recur in the renal allograft, suggesting the presence of a podocyte-toxic factor(s) in the recipient's serum. Currently, there is no reliable way to quantify the serum activity or predict the subset of FSGS patients at risk for recurrence after transplantation. We describe a novel in vitro method that measures the podocyte-toxic activity of sera from FSGS patients using cultured human podocytes; we compare this with the effect of compounds such as adriamycin. Using immunofluorescence microscopy followed by computerized image-processing analysis, we show that incubation of human podocytes with adriamycin leads to a dose-dependent disassembly of focal adhesion complexes (FACs). We then demonstrate that sera from patients with posttransplant recurrent or idiopathic FSGS cause a similar FAC disturbance. In contrast, sera from nonrecurrent FSGS patients do not affect FACs. In some FSGS patients, toxic effects of serum can be prevented by blockade of the tumor necrosis factor-α pathway. We propose that this method may be useful as a diagnostic tool to identify FSGS patients with serum podocyte-toxic activity that presumably places them at increased risk for recurrence in the renal allograft.
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Affiliation(s)
- Nadezda Kachurina
- Department of Medicine, McGill University and McGill University Health Center, Montreal, Quebec, Canada
| | - Chen-Fang Chung
- Department of Medicine, McGill University and McGill University Health Center, Montreal, Quebec, Canada
| | - Erin Benderoff
- Department of Medicine, McGill University and McGill University Health Center, Montreal, Quebec, Canada
| | - Sima Babayeva
- Department of Medicine, McGill University and McGill University Health Center, Montreal, Quebec, Canada
| | - Martin Bitzan
- The Montreal Children's Hospital, Department of Paediatric Nephrology, McGill University Health Center, Montreal, Quebec, Canada
| | - Paul Goodyer
- The Montreal Children's Hospital, Department of Paediatric Nephrology, McGill University Health Center, Montreal, Quebec, Canada; Department of Human Genetics, McGill University, Montreal, Quebec, Canada
| | - Thomas Kitzler
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada
| | - Dany Matar
- McKinsey & Company, Washington, District of Columbia; and
| | - Andrey V Cybulsky
- Department of Medicine, McGill University and McGill University Health Center, Montreal, Quebec, Canada
| | - Nada Alachkar
- Division of Nephrology, The Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Elena Torban
- Department of Medicine, McGill University and McGill University Health Center, Montreal, Quebec, Canada;
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Giglio S, Provenzano A, Mazzinghi B, Becherucci F, Giunti L, Sansavini G, Ravaglia F, Roperto RM, Farsetti S, Benetti E, Rotondi M, Murer L, Lazzeri E, Lasagni L, Materassi M, Romagnani P. Heterogeneous genetic alterations in sporadic nephrotic syndrome associate with resistance to immunosuppression. J Am Soc Nephrol 2014; 26:230-6. [PMID: 25060053 DOI: 10.1681/asn.2013111155] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
In children, sporadic nephrotic syndrome can be related to a genetic cause, but to what extent genetic alterations associate with resistance to immunosuppression is unknown. In this study, we designed a custom array for next-generation sequencing analysis of 19 target genes, reported as possible causes of nephrotic syndrome, in a cohort of 31 children affected by sporadic steroid-resistant nephrotic syndrome and 38 patients who exhibited a similar but steroid-sensitive clinical phenotype. Patients who exhibited extrarenal symptoms, had a familial history of the disease or consanguinity, or had a congenital onset were excluded. We identified a genetic cause in 32.3% of the children with steroid-resistant disease but zero of 38 children with steroid-sensitive disease. Genetic alterations also associated with lack of response to immunosuppressive agents in children with steroid-resistant disease (0% of patients with alterations versus 57.9% of patients without alterations responded to immunosuppressive agents), whereas clinical features, age at onset, and pathologic findings were similar in steroid-resistant patients with and without alterations. These results suggest that heterogeneous genetic alterations in children with sporadic forms of nephrotic syndrome associate with resistance to steroids as well as immunosuppressive treatments. In these patients, a comprehensive screening using such an array may, thus, be useful for genetic counseling and may help clinical decision making in a fast and cost-efficient manner.
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Affiliation(s)
- Sabrina Giglio
- Department of Biomedical Experimental and Clinical Sciences "Mario Serio," and Medical Genetics and
| | - Aldesia Provenzano
- Department of Biomedical Experimental and Clinical Sciences "Mario Serio," and
| | | | - Francesca Becherucci
- Pediatric Nephrology Units, Meyer Children's University Hospital, Florence, Italy
| | | | - Giulia Sansavini
- Pediatric Nephrology Units, Meyer Children's University Hospital, Florence, Italy
| | - Fiammetta Ravaglia
- Pediatric Nephrology Units, Meyer Children's University Hospital, Florence, Italy
| | - Rosa Maria Roperto
- Pediatric Nephrology Units, Meyer Children's University Hospital, Florence, Italy
| | - Silvia Farsetti
- Pediatric Nephrology Units, Meyer Children's University Hospital, Florence, Italy
| | - Elisa Benetti
- Department of Pediatrics, University of Padua, Padua, Italy; and
| | - Mario Rotondi
- Unit of Internal Medicine and Endocrinology, Fondazione Salvatore Maugeri IRCCS, University of Pavia, Pavia, Italy
| | - Luisa Murer
- Department of Pediatrics, University of Padua, Padua, Italy; and
| | - Elena Lazzeri
- Excellence Centre for Research, Transfer and High Education for the Development of DE NOVO Therapies (DENOTHE), University of Florence, Florence, Italy
| | - Laura Lasagni
- Excellence Centre for Research, Transfer and High Education for the Development of DE NOVO Therapies (DENOTHE), University of Florence, Florence, Italy
| | - Marco Materassi
- Pediatric Nephrology Units, Meyer Children's University Hospital, Florence, Italy
| | - Paola Romagnani
- Department of Biomedical Experimental and Clinical Sciences "Mario Serio," and Pediatric Nephrology Units, Meyer Children's University Hospital, Florence, Italy; Excellence Centre for Research, Transfer and High Education for the Development of DE NOVO Therapies (DENOTHE), University of Florence, Florence, Italy;
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Ding WY, Koziell A, McCarthy HJ, Bierzynska A, Bhagavatula MK, Dudley JA, Inward CD, Coward RJ, Tizard J, Reid C, Antignac C, Boyer O, Saleem MA. Initial steroid sensitivity in children with steroid-resistant nephrotic syndrome predicts post-transplant recurrence. J Am Soc Nephrol 2014; 25:1342-8. [PMID: 24511128 DOI: 10.1681/asn.2013080852] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Of children with idiopathic nephrotic syndrome, 10%-20% fail to respond to steroids or develop secondary steroid resistance (termed initial steroid sensitivity) and the majority progress to transplantation. Although 30%-50% of these patients suffer disease recurrence after transplantation, with poor long-term outcome, no reliable indicator of recurrence has yet been identified. Notably, the incidence of recurrence after transplantation appears reduced in patients with steroid-resistant nephrotic syndrome (SRNS) due to monogenic disorders. We reviewed 150 transplanted patients with SRNS to identify biomarkers that consistently predict outcome of SRNS after transplantation. In all, 25 children had genetic or familial SRNS and did not experience post-transplant recurrence. We reviewed phenotypic factors, including initial steroid sensitivity, donor type, age, ethnicity, time to ESRD, and time on dialysis, in the remaining 125 children. Of these patients, 57 (45.6%) developed post-transplant recurrence; 26 of 28 (92.9%) patients with initial steroid sensitivity recurred after transplantation, whereas only 26 of 86 (30.2%) patients resistant from the outset recurred (odds ratio, 30; 95% confidence interval, 6.62 to 135.86; P<0.001). We were unable to determine recurrence in two patients (one with initial steroid sensitivity), and nine patients did not receive initial steroids. Our data show that initial steroid sensitivity is highly predictive of post-transplant disease recurrence in this pediatric patient population. Because a pathogenic circulating permeability factor in nephrotic syndrome remains to be confirmed, we propose initial steroid sensitivity as a surrogate marker for post-transplant recurrence.
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Affiliation(s)
- Wen Y Ding
- Department of Paediatric Nephrology, Bristol Royal Hospital for Children, Bristol, United Kingdom; Academic Renal Unit, University of Bristol, Southmead Hospital, Bristol, United Kingdom
| | - Ania Koziell
- Department of Paediatric Nephrology, Evelina Children's Hospital, London, United Kingdom; Department of Experimental Immunobiology, King's College London, Guy's Hospital, London, United Kingdom
| | - Hugh J McCarthy
- Department of Paediatric Nephrology, Bristol Royal Hospital for Children, Bristol, United Kingdom; Academic Renal Unit, University of Bristol, Southmead Hospital, Bristol, United Kingdom
| | - Agnieszka Bierzynska
- Academic Renal Unit, University of Bristol, Southmead Hospital, Bristol, United Kingdom
| | | | - Jan A Dudley
- Department of Paediatric Nephrology, Bristol Royal Hospital for Children, Bristol, United Kingdom
| | - Carol D Inward
- Department of Paediatric Nephrology, Bristol Royal Hospital for Children, Bristol, United Kingdom
| | - Richard J Coward
- Department of Paediatric Nephrology, Bristol Royal Hospital for Children, Bristol, United Kingdom; Academic Renal Unit, University of Bristol, Southmead Hospital, Bristol, United Kingdom
| | - Jane Tizard
- Department of Paediatric Nephrology, Bristol Royal Hospital for Children, Bristol, United Kingdom
| | - Christopher Reid
- Department of Paediatric Nephrology, Evelina Children's Hospital, London, United Kingdom
| | - Corinne Antignac
- Pediatric Nephrology, French Institute of Health and Medical Research Unit 983, Necker Hospital for Sick Children, Paris, France
| | - Olivia Boyer
- Pediatric Nephrology, French Institute of Health and Medical Research Unit 983, Necker Hospital for Sick Children, Paris, France
| | - Moin A Saleem
- Department of Paediatric Nephrology, Bristol Royal Hospital for Children, Bristol, United Kingdom; Academic Renal Unit, University of Bristol, Southmead Hospital, Bristol, United Kingdom;
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Iyengar A, Kamath N, Phadke KD, Bitzan M. Cyclosporine/ketoconazole reduces treatment costs for nephrotic syndrome. Indian J Nephrol 2013; 23:419-23. [PMID: 24339519 PMCID: PMC3841509 DOI: 10.4103/0971-4065.120338] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Cyclosporine A (CyA) is an effective agent for the treatment of glucocorticoid-dependent idiopathic nephrotic syndrome (GCDNS), but costs are prohibitive in resource-poor societies. The objectives of this study were to evaluate the efficacy and safety of reducing the dose of CyA by co-administering ketoconazole. A prospective study targeting children 2-18 years of age with GCDNS in remission with CyA monotherapy was conducted. CyA dose was reduced by 50% and ketoconazole was added at 25% of the recommended therapeutic dose, and the drug levels and therapeutic and adverse effects (AE) were monitored. Continued combined therapy after completion of the 4-week trial period was offered. Ten patients (median age 9.5 years, range 3.0-16.0 years) were enrolled in the study. At week 4, the CyA dose was 2.2 ± 0.7 mg/kg/day compared with 5.6 ± 0.9 mg/kg/day at enrolment (P < 0.0001). No AE were noted. All patients continued ketoconazole treatment for at least 3 months. CyA drug cost savings were 61%, and approximately 60% with ketoconazole cost included. The combination of an expensive immunosuppressive drug with a cheap metabolic inhibitor reduced the treatment costs by> 50% without increased adverse events or drug monitoring needs. This intervention demonstrates how access of patients with limited resources to needed drugs can be improved by interference with physiological drug elimination.
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Affiliation(s)
- A Iyengar
- Division of Pediatric Nephrology, St John's Medical College Hospital, Bangalore, India
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Demirhan E, Eskut NP, Zorlu Y, Cukurova I, Tuna G, Kirkali FG. Blood levels of TNF-α, IL-10, and IL-12 in idiopathic sudden sensorineural hearing loss. Laryngoscope 2013; 123:1778-81. [PMID: 23382065 DOI: 10.1002/lary.23907] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/31/2012] [Indexed: 12/20/2022]
Abstract
OBJECTIVES/HYPOTHESIS To investigate the blood levels of TNF-α, IL-10, and IL-12 in the idiopathic sudden sensorineural hearing loss patients, and the change of these cytokine levels after treatment. STUDY DESIGN Prospective clinical trial. METHODS Twenty-three patients with idiopathic sudden sensorineural hearing loss and 20 healthy people were selected as study and control groups. Blood samples for TNF-α, IL-10, and IL-12 were taken before treatment and 6 weeks after treatment. The study group was given combined treatment including dexamethasone, heparin, pentoxifyline, vitamin B1, and B6 for 10 days, and was divided into two groups: treatment responders and treatment nonresponders. The treatment responders group was also divided into three groups according to most accepted criteria for improvement in the literature. Audiograms were taken before treatment and 6 weeks after treatment to determine the response to the treatment. RESULTS There was no significant difference between pre- and posttreatment values of IL-10 and IL-12 in all study groups (P > 0.05). There was also no significant difference between pre- and posttreatment values of TNF-α in treatment responders (P > 0.05). Treatment nonresponders had more elevated posttreatment values of TNF-α than pretreatment values (P < 0.05). CONCLUSION IL-10 and IL-12 may not play a critical role in idiopathic sudden sensorineural hearing loss. But our data supports the role of TNF-α in the pathophysiology of idiopathic sudden sensorineural hearing loss, and TNF-α receptor blockers may have benefits in these patients.
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Affiliation(s)
- Erhan Demirhan
- Department of Otorhinolaryngology, Eregli State Hospital, Zonguldak, Turkey.
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