701
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Malina M, Cinek O, Janda J, Seeman T. Partial remission with cyclosporine A in a patient with nephrotic syndrome due to NPHS2 mutation. Pediatr Nephrol 2009; 24:2051-3. [PMID: 19495806 DOI: 10.1007/s00467-009-1211-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2009] [Revised: 03/23/2009] [Accepted: 04/16/2009] [Indexed: 10/20/2022]
Abstract
Autosomal recessive steroid-resistant nephrotic syndrome (NS) is a rare, genetically determined nephropathy caused mainly by a mutation in the NPHS2 gene. This type of NS is usually resistant to other immunosuppressive therapy as well, but a few cases of cyclosporine A-induced partial remission of inherited NS have been reported. We present a boy that developed NS at the age of 18 months. There was no decrease of proteinuria on standard prednisolone therapy, and a diagnosis of steroid-resistant NS was established. However, the proteinuria decreased significantly following the initiation of cyclosporine A therapy (from 1280 to 380 mg/m(2) per day) without any negative effects on renal function (stable glomerular filtration rate 130-150 ml/min per 1.73 m(2)). The molecular genetic test revealed a homozygous R138Q mutation in the NPHS2 gene. Our case demonstrates that cyclosporine A can induce partial remission in patients with genetic forms of NS without influencing the glomerular filtration rate. However, its long-term effect and safety in children with hereditary forms of nephrotic syndrome have yet to be investigated.
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Affiliation(s)
- Michal Malina
- Department of Pediatrics, Second Faculty of Medicine, Charles University-Prague, Prague 5, Czech Republic.
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702
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Eguchi A, Takei T, Yoshida T, Tsuchiya K, Nitta K. Combined cyclosporine and prednisolone therapy in adult patients with the first relapse of minimal-change nephrotic syndrome. Nephrol Dial Transplant 2009; 25:124-9. [DOI: 10.1093/ndt/gfp422] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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703
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Trivedi S, Zeier M, Reiser J. Role of podocytes in lupus nephritis. Nephrol Dial Transplant 2009; 24:3607-12. [DOI: 10.1093/ndt/gfp427] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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704
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Abstract
PURPOSE OF REVIEW In 2008, more than 376 papers were published on the glomerular barrier. Most of them dealt with the podocyte and its role in kidney disease. RECENT FINDINGS There is new information on signaling pathways that are utilized in podocytes during proteinuria. Interestingly, the glomerular endothelium, with its fenestrae and glycocalyx, seems to be important for the maintenance of an intact glomerular barrier. All new advances at the molecular level are compatible with a highly size and charge-selective glomerular membrane and refute the concept of a 'leaky' glomerular barrier with tubular retrieval of intact albumin. Still, the hypothesis has its advocates, keeping a stimulating 'charge debate' alive. SUMMARY Glomerular diseases account for 90% of chronic kidney disease requiring dialysis and transplantation at an annual cost of $20 billion in the USA. In clinical practice, we lack specific treatment of these diseases, giving us plenty of room for improvement. Future research should be directed toward deeper understanding of the signaling pathways involved in different conditions of proteinuria, the cross-talk between cell types in the glomerulus, and the identification of novel targets for treatment of acquired kidney disease.
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705
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The glomerular filter: an imperfect barrier is required for perfect renal function. Curr Opin Nephrol Hypertens 2009; 18:336-42. [PMID: 19474730 DOI: 10.1097/mnh.0b013e32832cb96a] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
PURPOSE OF REVIEW There is currently a major debate on the mechanisms of albuminuria, and this review appraises recent studies in this area. RECENT FINDINGS The traditional view of albuminuria is that it is the result of damage to an essentially impermeable glomerular barrier. However, over the years, critical evidence for this traditional model has been shown to be flawed. An alternative explanation has evolved in which the glomerular filter governs albumin permeability by size selectivity alone. This means that the filter offers a significant barrier to albumin, but it is imperfect - the barrier leaks albumin. The virtue of this leakage is that it endows the filter an in-built anticlogging mechanism. The filtered albumin, if not rescued, would be excreted at nephrotic levels in the urine. There is evidence that proximal tubular cells participate in retrieving most of this filtered albumin to return it back to the blood supply intact. A small amount of the filtered albumin is not retrieved but directed toward lysosomal degradation, and the peptide products are exocytosed into the tubular lumen and excreted. SUMMARY In acquired and chemically induced kidney disease, albuminuria is the result of dysfunction in proximal tubular cell processing of albumin rather than alterations in glomerular permeability.
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706
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Miyasaka N, Kawai S, Hashimoto H. Efficacy and safety of tacrolimus for lupus nephritis: a placebo-controlled double-blind multicenter study. Mod Rheumatol 2009; 19:606-15. [PMID: 19688181 DOI: 10.1007/s10165-009-0218-5] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2009] [Accepted: 07/16/2009] [Indexed: 11/29/2022]
Abstract
We evaluated the efficacy and safety of tacrolimus in patients receiving glucocorticoid therapy for lupus nephritis. Patients with persistent nephritis were randomized to receive 28 weeks of double-blind treatment with tacrolimus (3 mg/day) or placebo. The primary endpoint was the change in the lupus nephritis disease activity index (LNDAI) calculated from scores for daily urinary protein excretion, urinary red cells, serum creatinine, anti-double-stranded DNA antibody, and serum complement. Statistical analysis was performed using the full analysis set. The LNDAI was decreased by 32.9 +/- 31.0% (mean +/- SD) in the tacrolimus group (n = 28) and was increased by 2.3 +/- 38.2% in the placebo group (n = 35) at final evaluation. There was significant improvement in the tacrolimus group. Daily urinary protein excretion showed a significant decrease in the tacrolimus group (p < 0.001). The complement (C3) level showed a significant increase in the tacrolimus group (p = 0.001). Treatment-related adverse events occurred in 92.9% of the tacrolimus group and 80.0% of the placebo group, but the difference was not significant. In patients on glucocorticoid therapy for lupus nephritis, addition of tacrolimus to basal therapy achieved significant improvement compared with placebo. Tacrolimus may therefore be a useful alternative treatment for lupus nephritis.
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Affiliation(s)
- Nobuyuki Miyasaka
- Department of Medicine and Rheumatology, Graduate School, Tokyo Medicine and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8519, Japan.
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707
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Zenker M, Machuca E, Antignac C. Genetics of nephrotic syndrome: new insights into molecules acting at the glomerular filtration barrier. J Mol Med (Berl) 2009; 87:849-57. [PMID: 19649571 DOI: 10.1007/s00109-009-0505-9] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2009] [Revised: 07/09/2009] [Accepted: 07/13/2009] [Indexed: 12/30/2022]
Abstract
Nephrotic syndrome is caused by increased permeability of the glomerular filtration barrier for macromolecules. The identification of mutations of various podocyte-expressed proteins as causes of familial nephrotic syndrome has significantly contributed to shedding light into the molecular pathogenesis of nephrotic proteinuria and into the physiology of the glomerular sieve. More recent findings have changed our conception of the glomerular filtration barrier from a relatively static structure to a highly dynamic one. Both the multiprotein slit diaphragm complex around nephrin and the integrin receptor complex that mediates binding of the podocyte to the glomerular basement membrane, may translate outside-inside signaling and lead to podocyte actin cytoskeleton rearrangement. This may enable the podocyte network to adapt to environmental changes and respond to injury. Disturbance in these processes may not only be involved in the pathogenesis of hereditary nephrotic syndrome but also in that of more common acquired proteinuric diseases. Elucidation of the molecular mechanisms involved will possibly open the way to new therapeutic approaches.
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Affiliation(s)
- Martin Zenker
- Institute of Human Genetics, University Hospital Erlangen, University of Erlangen-Nuremberg, Schwabachanlage 10, 91054, Erlangen, Germany,
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708
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Kengne-Wafo S, Massella L, Diomedi-Camassei F, Gianviti A, Vivarelli M, Greco M, Stringini GR, Emma F. Risk factors for cyclosporin A nephrotoxicity in children with steroid-dependant nephrotic syndrome. Clin J Am Soc Nephrol 2009; 4:1409-16. [PMID: 19628686 DOI: 10.2215/cjn.01520209] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
BACKGROUND AND OBJECTIVES Cyclosporin A (CsA) is a well-established treatment for steroid-dependent nephrotic syndrome (SDNS) that may, however, cause chronic ischemic renal lesions. The objective of the study was to assess the prevalence of CsA nephrotoxicity (CsAN) in protocol biopsies of children with SDNS. DESIGN, SETTINGS, PARTICIPANTS, & MEASUREMENTS From 1990 through 2008, we performed 71 renal biopsies in 53 patients with SDNS. The mean CsA C2 levels were 466 +/- 134 ng/ml, and the mean duration of treatment was 4.7 +/- 2.0 yr before biopsy (range 2.9 to 12.7 yr). RESULTS CsAN was observed in 22 (31%) of 71 renal biopsies. Of these, 11 corresponded to isolated vascular or tubular lesions, and 11 corresponded to combined vascular and tubular lesions. The majority of CsAN lesions were mild (17 of 22). In no cases were lesions graded as severe. By regression analysis, CsAN was positively associated with the use of angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin II receptor blockers (ARBs) and with hyperuricemia and negatively associated with minimal-change lesions. By multivariate analysis, only association with the use of ACEIs or ARBs retained significance. Stratification of the population according to CsA C2 levels showed increased risk for CsAN for C2 levels >600 ng/ml. CONCLUSIONS Mild to moderate CsAN occurs in approximately one third of patients who have SDNS and are treated with CsA for >3 yr. Our data suggest that patients who require high dosages of CsA or treatment for hypertension, in particular when ACEIs/ARBs are used, are at higher risk for CsAN.
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Affiliation(s)
- Severin Kengne-Wafo
- Division of Nephrology, Bambino Gesù Children's Hospital and Research Institute, 00165 Rome, Italy
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709
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Sheerin NS. A Novel Role for Nephrin in the Maintenance of Glomerular Structure. J Am Soc Nephrol 2009; 20:1661-3. [DOI: 10.1681/asn.2009060596] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
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710
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Megremis S, Mitsioni A, Mitsioni AG, Fylaktou I, Kitsiou-Tzelli S, Stefanidis CJ, Kanavakis E, Traeger-Synodinos J. Nucleotide variations in the NPHS2 gene in Greek children with steroid-resistant nephrotic syndrome. Genet Test Mol Biomarkers 2009; 13:249-56. [PMID: 19371226 DOI: 10.1089/gtmb.2008.0083] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Mutations in the NPHS2 gene, encoding podocin, are a major cause of autosomal-recessive steroid-resistant nephrotic syndrome (SRNS) in childhood, accounting for up to 30% of sporadic and 20-40% of familial cases. Among 22 Greek children with a clinical diagnosis of SRNS, mutation analysis was performed in all eight NPHS2 gene exons, using denaturing gradient gel electrophoresis and DNA sequencing. The frequency of all nucleotide variations found in patients was also evaluated in 100 unrelated samples (18-30 years) with no known history of nephrotic disease. Three pathogenic genotypes (R138Q/R138Q, R229Q/A295T, and R168H/R168H) accounted for 3/14 (21%) of sporadic patients; the A295T mutation in exon 8 (c.883G>A) is novel and predicted in silico to be pathogenic. Among the familial cases, a single patient was heterozygous for R229Q. Several known polymorphisms were found, including the in cis variants IVS3-46C>T plus IVS3-21C>T, IVS7+7A>G A and exonic variants S96S (c.288C>T), A318A (c.954T>C), and L346L (c.1038A>G), with allele frequencies comparable to those in other populations. A novel substitution (IVS3-17C>T) was found in two related patients, but in no controls. In conclusion, podocin mutations do not appear to be a major cause of SRNS in Greek children, although the study cohort was small. However, NPHS2 gene analysis could still be considered in Greek SRNS patients to support appropriate management. The present study also contributes potentially useful observations for the clinical management of SRNS patients.
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Affiliation(s)
- Spyridon Megremis
- Medical Genetics, Aghia Sofia Children's Hospital, Athens University, Athens, Greece
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711
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Patrakka J, Tryggvason K. New insights into the role of podocytes in proteinuria. Nat Rev Nephrol 2009; 5:463-8. [DOI: 10.1038/nrneph.2009.108] [Citation(s) in RCA: 139] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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712
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Hussain S, Romio L, Saleem M, Mathieson P, Serrano M, Moscat J, Diaz-Meco M, Scambler P, Koziell A. Nephrin deficiency activates NF-kappaB and promotes glomerular injury. J Am Soc Nephrol 2009; 20:1733-43. [PMID: 19497968 DOI: 10.1681/asn.2008111219] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Increasing evidence implicates activation of NF-kappaB in a variety of glomerular diseases, but the mechanisms involved are unknown. Here, upregulation of NF-kappaB in the podocytes of transgenic mice resulted in glomerulosclerosis and proteinuria. Absence of the podocyte protein nephrin resulted in NF-kappaB activation, suggesting that nephrin negatively regulates the NF-kappaB pathway. Signal transduction assays supported a functional relationship between nephrin and NF-kappaB and suggested the involvement of atypical protein kinase C (aPKCzeta/lambda/iota) as an intermediary. We propose that disruption of the slit diaphragm leads to activation of NF-kappaB; subsequent upregulation of NF-kappaB-driven genes results in glomerular damage mediated by NF-kappaB-dependent pathways. In summary, nephrin may normally limit NF-kappaB activity in the podocyte, suggesting a mechanism by which it might discourage the evolution of glomerular disease.
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Affiliation(s)
- Sagair Hussain
- Molecular Medicine Unit, Institute of Child Health, London, UK.
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713
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Meyrier AY. Treatment of focal segmental glomerulosclerosis with immunophilin modulation: when did we stop thinking about pathogenesis? Kidney Int 2009; 76:487-91. [PMID: 19494796 DOI: 10.1038/ki.2009.204] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Nephrotic focal segmental glomerulosclerosis (FSGS) represents a difficult therapeutic challenge. FSGS has long been considered a subset of idiopathic nephrotic syndrome, lumping together FSGS and minimal change disease (MCD). The time-honored 'Shalhoub hypothesis' has led to treating FSGS as a T-cell-driven condition in which a lymphokine, considered without proof as being the 'glomerular permeability factor,' induces proteinuria and podocyte functional and structural derangement. This has led to trying, in addition to steroids, every new drug marketed in the field of organ transplantation, first cyclosporine (CsA) and then other immunophilin modulators. The fact that alkylating agents and mycophenolate mofetil have obtained a poor and inconstant favorable effect, and that rituximab may obtain remissions, although inconstantly, has not led to reconsidering the T-cell hypothesis. This wrong thinking has fostered innumerable, mostly uncontrolled, treatment trials with various immunosuppressive agents. In fact, clinicians have not considered the fact that some but not all immunophilin modulators may be effective as nonspecific antiproteinuric agents, rather than as immunosuppressive drugs, and that treatment success does not exclude a non-immunologic pathophysiology. Recent findings on the mode of action of CsA and FK-506 have lent support to this concept. This review should be considered as a plea to reconsider the pathogenesis of nephrotic FSGS, applying all efforts to the identification of the factor, or factors, responsible for nephrotic FSGS, and to fund treatment to counteract the 'factor,' rather than pursuing costly and non-evidence-based immunosuppressive therapeutic trials.
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Affiliation(s)
- Alain Y Meyrier
- Department of Nephrology, University Paris-Descartes, Hôpital Georges Pompidou and Broussais, 20 rue Leblanc, Paris F-75015, France.
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714
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Hashimura Y, Nozu K, Kanegane H, Miyawaki T, Hayakawa A, Yoshikawa N, Nakanishi K, Takemoto M, Iijima K, Matsuo M. Minimal change nephrotic syndrome associated with immune dysregulation, polyendocrinopathy, enteropathy, X-linked syndrome. Pediatr Nephrol 2009; 24:1181-6. [PMID: 19189134 DOI: 10.1007/s00467-009-1119-8] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2008] [Revised: 01/05/2009] [Accepted: 01/05/2009] [Indexed: 12/24/2022]
Abstract
Several studies have suggested that T cell-producing permeability factors might lead to proteinuria in minimal change nephrotic syndrome (MCNS). However, it is still unclear whether T-cell abnormalities cause MCNS. Immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) syndrome is a rare disorder of the immune regulation system, which leads to severe autoimmune phenomena including autoimmune enteropathy, atopic dermatitis with high levels of serum immunoglobulin E (IgE), type 1 diabetes mellitus (T1DM), and severe infection such as sepsis, which frequently result in death within the first 2 years of life. This disease is caused by mutations in the FOXP3 gene that result in the defective development of regulatory T (Treg) cells. This report describes a 5-year-old boy with IPEX syndrome with a 3 bp deletion in the FOXP3 gene (c.748-750delAAG, p.250K.del) and a paucity of CD4(+) CD25(+) FOXP3(+) T cells. The boy's condition was complicated by MCNS in addition to many IPEX-related manifestations, such as atopic dermatitis, T1DM, enteropathy, sepsis and hemolytic anemia. This is the first report of IPEX syndrome complicated by MCNS, and our findings imply that Treg cell dysfunction may be crucial for the development of MCNS.
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Affiliation(s)
- Yuya Hashimura
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
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715
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Meyrier A. An update on the treatment options for focal segmental glomerulosclerosis. Expert Opin Pharmacother 2009; 10:615-28. [PMID: 19284364 DOI: 10.1517/14656560902754029] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Focal segmental glomerulosclerosis (FSGS) is not a disease but a lesion initially affecting the podocyte. Various factors may induce 'secondary' FSGS, including defects in molecules that contribute to the podocyte slit diaphragm permselectivity to albumin. They do not represent indications for immunosuppression and require symptomatic treatment only, comprising angiotensin 2 and endothelin antagonists. Primary (idiopathic) FSGS is possibly but not certainly of immunologic origin, owing to an elusive glomerular permeability factor (GPF), explaining relapse on a renal transplant and justifying an immunosuppressive treatment. The best prognostic feature of primary nephrotic FSGS is its response to corticosteroids. Alkylating agents are mostly ineffective in steroid-resistant forms. An association of corticosteroids and cyclosporine A (CsA) remains the mainstay of treatment, with a good tolerability when CsA dosage is low. A definite advantage of tacrolimus on CsA has not yet been established. Sirolimus appears ineffective and potentially harmful. Azathioprine is not indicated. A number of mostly uncontrolled trials indicate that mycophenolate mofetil might find an adjunctive place in the treatment. Plasmapheresis is of no avail outside the special case of relapse in a transplanted kidney. Immunoabsorption of the GPF has not led to practical treatment options. Anecdotal reports on rituximab are as yet too few to determine whether this monoclonal anti-CD20 antibody will find a place in the treatment of primary FSGS.
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Affiliation(s)
- Alain Meyrier
- Université Paris-Descartes, Hôpital Georges Pompidou, Paris, France.
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716
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Santín S, Ars E, Rossetti S, Salido E, Silva I, García-Maset R, Giménez I, Ruíz P, Mendizábal S, Luciano Nieto J, Peña A, Camacho JA, Fraga G, Cobo MA, Bernis C, Ortiz A, de Pablos AL, Sánchez-Moreno A, Pintos G, Mirapeix E, Fernández-Llama P, Ballarín J, Torra R, Zamora I, López-Hellin J, Madrid A, Ventura C, Vilalta R, Espinosa L, García C, Melgosa M, Navarro M, Giménez A, Cots JV, Alexandra S, Caramelo C, Egido J, San José MDM, de la Cerda F, Sala P, Raspall F, Vila A, Daza AM, Vázquez M, Ecija JL, Espinosa M, Justa ML, Poveda R, Aparicio C, Rosell J, Muley R, Montenegro J, González D, Hidalgo E, de Frutos DB, Trillo E, Gracia S, de los Ríos FJG. TRPC6 mutational analysis in a large cohort of patients with focal segmental glomerulosclerosis. Nephrol Dial Transplant 2009; 24:3089-96. [PMID: 19458060 DOI: 10.1093/ndt/gfp229] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Mutations in the TRPC6 gene have been reported in six families with adult-onset (17-57 years) autosomal dominant focal segmental glomerulosclerosis (FSGS). Electrophysiology studies confirmed augmented calcium influx only in three of these six TRPC6 mutations. To date, the role of TRPC6 in childhood and adulthood non-familial forms is unknown. METHODS TRPC6 mutation analysis was performed by direct sequencing in 130 Spanish patients from 115 unrelated families with FSGS. An in silico scoring matrix was developed to evaluate the pathogenicity of amino acid substitutions, by using the bio-physical and bio-chemical differences between wild-type and mutant amino acid, the evolutionary conservation of the amino acid residue in orthologues, homologues and defined domains, with the addition of contextual information. RESULTS Three new missense substitutions were identified in two clinically non-familial cases and in one familial case. The analysis by means of this scoring system allowed us to classify these variants as likely pathogenic mutations. One of them was detected in a female patient with unusual clinical features: mesangial proliferative FSGS in childhood (7 years) and partial response to immunosupressive therapy (CsA + MMF). Asymptomatic carriers of this likely mutation were found within her family. CONCLUSIONS We describe for the first time TRPC6 mutations in children and adults with non-familial FSGS. It seems that TRPC6 is a gene with a very variable penetrance that may contribute to glomerular diseases in a multi-hit setting.
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Affiliation(s)
- Sheila Santín
- Fundació Puigvert, Universitat Autònoma de Barcelona, REDinREN, Instituto de Investigación Carlos III, Barcelona, Spain
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717
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Li X, Li H, Ye H, Li Q, He X, Zhang X, Chen Y, Han F, He Q, Wang H, Chen J. Tacrolimus therapy in adults with steroid- and cyclophosphamide-resistant nephrotic syndrome and normal or mildly reduced GFR. Am J Kidney Dis 2009; 54:51-8. [PMID: 19406543 DOI: 10.1053/j.ajkd.2009.02.018] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2008] [Accepted: 02/28/2009] [Indexed: 11/11/2022]
Abstract
BACKGROUND In a proportion of adults with steroid-resistant nephrotic syndrome (SRNS), intravenous cyclophosphamide therapy fails. Tacrolimus may be a promising alternative to cyclophosphamide for such patients. STUDY DESIGN Prospective observational study. SETTING & PARTICIPANTS 19 adults with SRNS (6 with minimal change nephropathy, 8 with focal segmental glomerulosclerosis [FSGS], and 5 with mesangioproliferative glomerulonephritis) that did not respond to intravenous cyclophosphamide therapy were studied from January 2003 to September 2006. Oral tacrolimus was administered (target trough levels, 5 to 10 ng/mL) for 24 weeks, then reduced doses were given (target trough level, 3 to 6 ng/mL) for another 24 weeks. FACTORS Histopathologic types: minimal change nephropathy (n = 6), FSGS (n = 8), and mesangioproliferative glomerulonephritis (n = 5). OUTCOMES MEASUREMENTS outcome variables included complete remission (decrease in daily proteinuria to protein < or = 0.3 g/d), partial remission (decrease in daily proteinuria to protein < 3.5 g/d but > 0.3 g/d), relapse (increase in daily proteinuria to protein > or = 3.5 g/d in patients who had partial or complete remission), change in kidney function, and tacrolimus dosing and serum levels. RESULTS 17 patients completed at least 24 weeks of tacrolimus therapy. Complete remission was achieved in 11 patients (64.7%), and partial remission was achieved in 3 (17.6%). Complete or partial remission was achieved in 5 of 5 patients with minimal change nephropathy, 4 of 7 patients with FSGS, and 5 of 5 patients with mesangioproliferative glomerulonephritis. Primary resistance to tacrolimus was seen in 3 patients (17.6%), all with FSGS. Mean times to achieve partial and complete remission were 5.6 +/- 1.4 and 8.0 +/- 5.1 weeks, respectively. In patients who achieved complete or partial remission, 35.7% experienced relapse during follow-up (mean, 37.6 +/- 13.4 months). Two patients had doubling of serum creatinine levels, both with FSGS. LIMITATIONS Observational study. CONCLUSIONS Tacrolimus rapidly and effectively induced remission of SRNS in Chinese adults with disease refractory to treatment with intravenous cyclophosphamide. Treatment may be less effective in patients with FSGS.
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Affiliation(s)
- Xiayu Li
- Kidney Disease Center, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang Province, People's Republic of China
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718
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Bruneau S, Dantal J. New insights into the pathophysiology of idiopathic nephrotic syndrome. Clin Immunol 2009; 133:13-21. [PMID: 19410518 DOI: 10.1016/j.clim.2009.03.532] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2009] [Accepted: 03/26/2009] [Indexed: 01/08/2023]
Abstract
Corticoresistant idiopathic nephrotic syndrome (INS) is a glomerulopathy of unknown etiology whose original aspect is its recurrence after kidney transplantation in 30 to 50% of patients with end-stage renal disease. This suggests the involvement of circulating factors that would alter the glomerular filtration barrier, but whose nature remains elusive. Although a T cell immune origin has been suggested, the actual role of these cells in INS recurrence is still unclear. Here we present an 8-year-old patient with corticoresistant INS who developed a recurrence of her initial disease after kidney transplantation. Rituximab therapy was proposed 11 months after transplantation; although no immediate effect was induced, a slow but persistent decrease in proteinuria began a few months after Rituximab infusions despite cessation of plasma exchanges and steroid therapy. The pathophysiology of INS and the putative mechanisms of action of Rituximab are discussed.
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719
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720
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Canaud G, Zuber J, Sberro R, Royale V, Anglicheau D, Snanoudj R, Gaha K, Thervet E, Lefrère F, Cavazzana-Calvo M, Noël LH, Méjean A, Legendre C, Martinez F. Intensive and prolonged treatment of focal and segmental glomerulosclerosis recurrence in adult kidney transplant recipients: a pilot study. Am J Transplant 2009; 9:1081-6. [PMID: 19344432 DOI: 10.1111/j.1600-6143.2009.02580.x] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
No treatment has consistently induced long-term remission of proteinuria in adult patients with focal segmental glomerulosclerosis (FSGS) recurrence after kidney transplantation. We undertook an open-label, nonrandomized pilot trial of intensive and prolonged treatment of FSGS recurrence. Over an 18-month period, 10 adult kidney transplant recipients with FSGS recurrence received concomitantly high-dose steroids, intravenous cyclosporine for 14 days followed by oral cyclosporine therapy, and an intensive and prolonged course of plasma exchanges (PE). We compared this treatment with those of a control group of 19 patients with a FSGS recurrence transplanted between 1997 and 2005. Complete, rapid (mean 23 +/- 7 days) and sustained remission was obtained in 9/10 patients (90%) as opposed to 27% in the control group. At month 3 and month 12, proteinuria was 0.16 g/day (range 0.05-0.3 g/day) and 0.19 g/day (range 0.05-1 g/day) respectively. Only one patient remained in partial remission at month 12 but he had already lost two previous grafts due to FSGS recurrence. PEs were stopped at month 9 in all patients except for the patient with a partial remission who remains PE-dependent. This small pilot study provides very encouraging results demonstrating that this treatment rapidly achieves complete and sustained remission in a high proportion of patients.
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Affiliation(s)
- G Canaud
- Université Paris Descartes, 7 Rue de l'Ecole de Médecine, Paris 75007, France.
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721
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Abstract
The spine apparatus is an essential component of dendritic spines of cortical and hippocampal neurons, yet its functions are still enigmatic. Synaptopodin (SP), an actin-binding protein, is tightly associated with the spine apparatus and it may play a role in synaptic plasticity, but it has not yet been linked mechanistically to synaptic functions. We studied endogenous and transfected SP in dendritic spines of cultured hippocampal neurons and found that spines containing SP generate larger responses to flash photolysis of caged glutamate than SP-negative ones. An NMDA-receptor-mediated chemical long-term potentiation caused the accumulation of GFP-GluR1 in spine heads of control but not of shRNA-transfected, SP-deficient neurons. SP is linked to calcium stores, because their pharmacological blockade eliminated SP-related enhancement of glutamate responses, and release of calcium from stores produced an SP-dependent increase of GluR1 in spines. Thus, SP plays a crucial role in the calcium store-associated ability of neurons to undergo long-term plasticity.
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722
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723
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724
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Comper WD. Is the LPS-mediated proteinuria mouse model relevant to human kidney disease? Nat Med 2009; 15:133; author reply 133-4. [PMID: 19197281 DOI: 10.1038/nm0209-133a] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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725
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Abstract
Fabry disease, an X-linked disorder of glycosphingolipids that is caused by the deficiency of alpha-galactosidase A, is associated with dysfunction of many cell types and includes a systemic vasculopathy. As a result, patients have a markedly increased risk of developing small-fiber peripheral neuropathy, stroke, myriad cardiac manifestations and chronic renal disease. Virtually all complications of Fabry disease are non-specific in nature and clinically indistinguishable from similar abnormalities that occur in the context of more common disorders in the general population. Although Fabry disease was originally thought to be very rare, recent studies have found a much higher incidence of mutations of the GLA gene, suggesting that this disorder is under-diagnosed. Although the etiology of Fabry disease has been known for many years, the mechanism by which the accumulating alpha-D-galactosyl moieties cause this multi-organ disorder has only recently been studied and is yet to be completely elucidated. Specific therapy for Fabry disease has been developed in the last few years but its role in the management of the disorder is still being investigated. Fortunately, standard 'non-specific' medical and surgical therapy is effective in slowing deterioration or compensating for organ failure in patients with Fabry disease. All these aspects are discussed in detail in the present review.
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Affiliation(s)
- Raphael Schiffmann
- Institute of Metabolic Disease, Baylor Research Institute, 3812 Elm Street, Dallas, TX 75226, USA.
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726
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Reiser J, Mundel P. Is the LPS-mediated proteinuria mouse model relevant to human kidney disease? Nat Med 2009. [DOI: 10.1038/nm0209-133b] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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727
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Schlöndorff J, Del Camino D, Carrasquillo R, Lacey V, Pollak MR. TRPC6 mutations associated with focal segmental glomerulosclerosis cause constitutive activation of NFAT-dependent transcription. Am J Physiol Cell Physiol 2009; 296:C558-69. [PMID: 19129465 DOI: 10.1152/ajpcell.00077.2008] [Citation(s) in RCA: 139] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Mutations in the canonical transient receptor potential channel TRPC6 lead to an autosomal dominant form of human kidney disease characterized histologically by focal and segmental glomerulosclerosis. Several of these mutations enhance the amplitude and duration of the channel current. However, the effect of these mutations on the downstream target of TRPC6, the nuclear factor of activated T cell (NFAT) transcription factors, has not been previously examined. Here we demonstrate that all three TRPC6 mutations previously shown to enhance channel activity lead to enhanced basal NFAT-mediated transcription in several cell lines, including cultured podocytes. These effects are dependent on channel activity and are dominant when mutants are coexpressed with wild-type TRPC6. While TRPC6 mutants do not demonstrate an increase in basal channel currents, a subset of cells expressing the R895C and E897K mutants have elevated basal calcium levels as measured by Fura-2 imaging. Activation of NFAT by TRPC6 mutants is blocked by inhibitors of calcineurin, calmodulin-dependent kinase II, and phosphatidylinositol 3-kinase. PP2 partially inhibits NFAT activation by mutant TRPC6 independently of Src, Yes, or Fyn. Differences in channel glycosylation and surface expression do not explain the ability of mutants to enhance NFAT activation. Taken together, these results identify the activation of the calcineurin-NFAT pathway as a potential mediator of focal segmental glomerulosclerosis.
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Affiliation(s)
- Johannes Schlöndorff
- Renal Division, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
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728
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Deschênes G, Doucet A. Free immunoglobulin light chains: A role in minimal change disease. ACTA ACUST UNITED AC 2009. [DOI: 10.1016/j.bihy.2009.03.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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729
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Affiliation(s)
- Peter W Mathieson
- Academic Renal Unit, University of Bristol and Southmead Hospital, Bristol, United Kingdom
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730
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Journal Club. Kidney Int 2008. [DOI: 10.1038/ki.2008.551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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