1
|
Kim YJ. A new pathological perspective on thrombotic microangiopathy. Kidney Res Clin Pract 2022; 41:524-532. [PMID: 35791743 PMCID: PMC9576460 DOI: 10.23876/j.krcp.22.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Accepted: 04/19/2022] [Indexed: 11/29/2022] Open
Abstract
Thrombotic microangiopathy (TMA) refers to a condition caused by microvascular injury that includes thrombosis, hemolytic anemia, and thrombocytopenia. There are two classic TMAs, hemolytic uremic syndrome (HUS) and thrombotic thrombocytopenic purpura, as well as an atypical HUS (aHUS). aHUS includes a broad spectrum of disorders with diverse etiologies and shares clinical manifestations with classic TMA; however, it frequently lacks typical clinical and laboratory findings. These traits can confuse clinicians and pathologists in terms of renal pathologic diagnosis, especially in cases where TMA is associated with other glomerulopathies or hypertensive renal disease. In this review, new paradigms for classifying TMA and the diversity of histopathologic changes including associated renal diseases are discussed. Renal biopsy is an important and useful diagnostic tool for diagnosing TMA and identifying TMA changes in other renal diseases, including hypertension. Adopting the term “TMA features” for TMA-like changes in glomerulus or artery/arteriole in addition to the pathological diagnosis of glomerulopathy would be informative to clinicians for a prompt diagnosis and treatment of aHUS.
Collapse
Affiliation(s)
- Yong-Jin Kim
- Department of Pathology, Kyungpook National University Hospital, Daegu, Republic of Korea
- Correspondence: Yong-Jin Kim Department of Pathology, Kyungpook National University Hospital, 130 Dongdeok-ro, Jung-gu, Daegu 41944, Republic of Korea. E-mail:
| |
Collapse
|
2
|
IgA nephropathy and atypical hemolytic uremic syndrome: a case series and a literature review. J Nephrol 2021; 35:1091-1100. [PMID: 34757577 DOI: 10.1007/s40620-021-01189-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 10/22/2021] [Indexed: 10/19/2022]
Abstract
BACKGROUND IgA nephropathy (IgAN) has been anecdotally reported in association with atypical hemolytic uremic syndrome (aHUS). The association likely portends poor renal outcome, and the possible relationship with complement overactivation has yet to be elucidated. We evaluated a series of IgAN patients with aHUS and reviewed the available literature. METHODS Adult patients who received a diagnosis of IgAN and developed aHUS between January 2009 and December 2019 were included in this retrospective review. RESULTS We identified six IgAN-aHUS patients, all of whom developed end-stage kidney disease. At aHUS presentation all patients had decreased serum C3 levels. Predisposing pathogenetic variants and risk haplotypes for aHUS in CFH gene heterozygosity were documented in four out of six patients. Anti-CFH antibodies were found to be negative in the five tested patients. In the literature we identified 21 case reports involving aHUS-IgAN and six retrospective studies evaluating the presence of TMA at the time of renal biopsy. Hypertension, severe proteinuria, reduced sC3 and a worse renal prognosis were the common features of most cases. CONCLUSION Our case series and literature review show that the onset of either aHUS or renal TMA in the course of IgAN are associated with very poor renal outcome. Activation of the alternative pathway revealed by consumption of serum C3 seems to play a major role. Our hypothesis is that the presence of a predisposing factor (e.g. dysregualtion of complement alternative pathway and/or other intrarenal precipitating factors) might be at the heart of aHUS-IgAN pathophysiology.
Collapse
|
3
|
Neves PDMDM, Souza RA, Torres FM, Reis FA, Pinheiro RB, Dias CB, Yu L, Woronik V, Furukawa LS, Cavalcante LB, de Almeida Araújo S, Wanderley DC, Malheiros DM, Jorge LB. Evidences of histologic thrombotic microangiopathy and the impact in renal outcomes of patients with IgA nephropathy. PLoS One 2020; 15:e0233199. [PMID: 33147224 PMCID: PMC7641451 DOI: 10.1371/journal.pone.0233199] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 09/30/2020] [Indexed: 12/12/2022] Open
Abstract
INTRODUCTION IgA nephropathy (IgAN) is the most common primary glomerulopathy worldwide. According to the Oxford Classification, changes in the kidney vascular compartment are not related with worse outcomes. This paper aims to assess the impact of thrombotic microangiopathy (TMA) in the outcomes of Brazilian patients with IgAN. MATERIALS AND METHODS Analysis of clinical data and kidney biopsy findings from patients with IgAN to assess the impact of TMA on renal outcomes. RESULTS The majority of the 118 patients included were females (54.3%); mean age of 33 years (25;43); hypertension and hematuria were observed in 67.8% and 89.8%, respectively. Median creatinine: 1.45mg/dL; eGFR: 48.8ml/min/1.73m2; 24-hour proteinuria: 2.01g; low serum C3: 12.5%. Regarding to Oxford Classification: M1: 76.3%; E1: 35.6%; S1: 70.3%; T1/T2: 38.3%; C1/C2: 28.8%. Average follow-up: 65 months. Histologic evidence of TMA were detected in 21 (17.8%) patients and those ones presented more frequently hypertension (100% vs. 61%, p <0.0001), hematuria (100% vs 87.6%, p = 0.0001), worse creatinine levels (3.8 vs. 1.38 mg/dL, p = 0.0001), eGFR (18 vs. 60 ml/min/1.73m2), p = 0.0001), low serum C3 (28.5% vs. 10.4%, p = 0.003), lower hemoglobin levels (10.6 vs. 12.7g/dL, p<0.001) and platelet counts (207,000 vs. 267,000, p = 0.001). Biopsy findings of individuals with TMA revealed only greater proportions of E1 (68% vs. 32%, p = 0.002). Individuals with TMA were followed for less time (7 vs. 65 months, p<0.0001) since they progressed more frequently to chronic kidney disease (CKD) requiring kidney replacement therapy (KRT) (71.4% vs. 21,6%, p<0.0001). Male sex, T1/T2, and TMA were independently associated with progression to CKD-KRT. CONCLUSIONS In this study patients with TMA had worse clinical manifestations and outcomes. In terms of histologic evidence, E1 distinguished patients with TMA from other patients. Further studies are necessary to analyze the impact of vascular lesions on IgAN prognosis.
Collapse
Affiliation(s)
| | - Rafael A. Souza
- Nephrology Division, University of São Paulo, School of Medicine, São Paulo, SP, Brazil
| | - Fábio M. Torres
- Nephrology Division, University of São Paulo, School of Medicine, São Paulo, SP, Brazil
| | - Fábio A. Reis
- Nephrology Division, University of São Paulo, School of Medicine, São Paulo, SP, Brazil
| | - Rafaela B. Pinheiro
- Pathology Division, University of São Paulo, School of Medicine, São Paulo, SP, Brazil
| | - Cristiane B. Dias
- Nephrology Division, University of São Paulo, School of Medicine, São Paulo, SP, Brazil
| | - Luis Yu
- Nephrology Division, University of São Paulo, School of Medicine, São Paulo, SP, Brazil
| | - Viktoria Woronik
- Nephrology Division, University of São Paulo, School of Medicine, São Paulo, SP, Brazil
| | - Luzia S. Furukawa
- Nephrology Division, University of São Paulo, School of Medicine, São Paulo, SP, Brazil
| | - Lívia B. Cavalcante
- Pathology Division, University of São Paulo, School of Medicine, São Paulo, SP, Brazil
| | - Stanley de Almeida Araújo
- Nephropathology Institute, Belo Horizonte, MG, Brazil
- Pathology Division, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - David Campos Wanderley
- Nephropathology Institute, Belo Horizonte, MG, Brazil
- Pathology Division, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - Denise M. Malheiros
- Pathology Division, University of São Paulo, School of Medicine, São Paulo, SP, Brazil
| | - Lectícia B. Jorge
- Nephrology Division, University of São Paulo, School of Medicine, São Paulo, SP, Brazil
| |
Collapse
|
4
|
Shi C, Li C, Ye W, Ye WL, Li MX. Nephrotic-range proteinuria and central nervous involvement in typical hemolytic uremic syndrome: a case report. BMC Nephrol 2020; 21:319. [PMID: 32736529 PMCID: PMC7395335 DOI: 10.1186/s12882-020-01979-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Accepted: 07/23/2020] [Indexed: 12/17/2022] Open
Abstract
Background Hemolytic uremic syndrome (HUS), a common subtype of thrombotic microangiopathy (TMA), is characterized by microangiopathic hemolytic anemia, thrombocytopenia, and acute kidney injury. Shiga toxin-producing Escherichia coli infection is the most common cause of post-diarrheal HUS. Kidney and central nervous system are the primary target organs. Case presentation A 64-year-old male presented with HUS following bloody diarrhea. Nephrotic-range proteinuria and hypoalbuminemia were present at the acute stage and renal histology revealed common TMA features. Neurological involvement presented as confusion and impaired cognitive function. Cranial magnetic resonance imaging demonstrated bilateral T2 hyperintensities in the brainstem and insula. The patient received plasma exchange and supportive care. Both the renal and neurological impairments were completely recovered 3 months after the onset. Conclusion We report an adult patient presenting with nephrotic-range proteinuria and central nervous system involvement at the acute phase of post-diarrheal HUS. The reversibility of the organ damages might predict a favorable outcome.
Collapse
Affiliation(s)
- Chuan Shi
- Department of Internal Medicine, Peking Union Medical College Hospital, Beijing, People's Republic of China
| | - Chao Li
- Department of Nephrology, Peking Union Medical College Hospital, Beijing, 100730, People's Republic of China.
| | - Wei Ye
- Department of Nephrology, Peking Union Medical College Hospital, Beijing, 100730, People's Republic of China
| | - Wen-Ling Ye
- Department of Nephrology, Peking Union Medical College Hospital, Beijing, 100730, People's Republic of China
| | - Ming-Xi Li
- Department of Nephrology, Peking Union Medical College Hospital, Beijing, 100730, People's Republic of China
| |
Collapse
|
5
|
Challis RC, Ring T, Xu Y, Wong EKS, Flossmann O, Roberts ISD, Ahmed S, Wetherall M, Salkus G, Brocklebank V, Fester J, Strain L, Wilson V, Wood KM, Marchbank KJ, Santibanez-Koref M, Goodship THJ, Kavanagh D. Thrombotic Microangiopathy in Inverted Formin 2 -Mediated Renal Disease. J Am Soc Nephrol 2017; 28:1084-1091. [PMID: 27974406 PMCID: PMC5373440 DOI: 10.1681/asn.2015101189] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Accepted: 10/19/2016] [Indexed: 12/26/2022] Open
Abstract
The demonstration of impaired C regulation in the thrombotic microangiopathy (TMA) atypical hemolytic uremic syndrome (aHUS) resulted in the successful introduction of the C inhibitor eculizumab into clinical practice. C abnormalities account for approximately 50% of aHUS cases; however, mutations in the non-C gene diacylglycerol kinase-ε have been described recently in individuals not responsive to eculizumab. We report here a family in which the proposita presented with aHUS but did not respond to eculizumab. Her mother had previously presented with a post-renal transplant TMA. Both the proposita and her mother also had Charcot-Marie-Tooth disease. Using whole-exome sequencing, we identified a mutation in the inverted formin 2 gene (INF2) in the mutational hotspot for FSGS. Subsequent analysis of the Newcastle aHUS cohort identified another family with a functionally-significant mutation in INF2 In this family, renal transplantation was associated with post-transplant TMA. All individuals with INF2 mutations presenting with a TMA also had aHUS risk haplotypes, potentially accounting for the genetic pleiotropy. Identifying individuals with TMAs who may not respond to eculizumab will avoid prolonged exposure of such individuals to the infectious complications of terminal pathway C blockade.
Collapse
Affiliation(s)
- Rachel C Challis
- National Renal Complement Therapeutics Centre, Institutes of *Genetic Medicine and
| | - Troels Ring
- Department of Nephrology, Aalborg University Hospital and
| | - Yaobo Xu
- National Renal Complement Therapeutics Centre, Institutes of *Genetic Medicine and
| | - Edwin K S Wong
- National Renal Complement Therapeutics Centre, Institutes of *Genetic Medicine and
| | | | - Ian S D Roberts
- Department of Cellular Pathology, Oxford University Hospitals National Health Service Trust, Oxford, United Kingdom
| | - Saeed Ahmed
- Department of Nephrology, City Hospitals Sunderland National Health Service Foundation Trust, Sunderland, United Kingdom
| | - Michael Wetherall
- Department of Pathology, Gateshead Health National Health Service Foundation Trust, Gateshead, United Kingdom
| | - Giedrius Salkus
- Department of Pathology, Aalborg University Hospital, Aalborg, Denmark
| | - Vicky Brocklebank
- National Renal Complement Therapeutics Centre, Institutes of *Genetic Medicine and
| | | | - Lisa Strain
- National Renal Complement Therapeutics Centre, Northern Molecular Genetics Service and
| | - Valerie Wilson
- National Renal Complement Therapeutics Centre, Northern Molecular Genetics Service and
| | - Katrina M Wood
- Department of Cellular Pathology, Newcastle upon Tyne Hospitals National Health Service Foundation Trust, Newcastle upon Tyne, United Kingdom
| | - Kevin J Marchbank
- Cellular Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom
| | | | - Timothy H J Goodship
- National Renal Complement Therapeutics Centre, Institutes of *Genetic Medicine and
| | - David Kavanagh
- National Renal Complement Therapeutics Centre, Institutes of *Genetic Medicine and
| |
Collapse
|
6
|
Doddi P, Gowda K, Ramachandran R, Nada R, Kumar V, Rathi M, Kohli HS, Gupta KL. Plasma exchange in Immunoglobulin A nephropathy with thrombotic microangiopathy and acute cortical necrosis. Indian J Nephrol 2016; 26:42-4. [PMID: 26937078 PMCID: PMC4753741 DOI: 10.4103/0971-4065.163423] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
A 25-year-old female presented with decreased urine output, deranged renal function, thrombocytopenia, and hemolytic anemia. Kidney biopsy was consistent with thrombotic microangiopathy with acute cortical necrosis and Immunoglobulin A nephropathy (IgAN). Hemolytic anemia, thrombocytopenia and urine output improved after five sessions of plasma exchange. Renal function showed a delayed recovery and serum creatinine normalized by 3 months. This is first case of successful use of plasma exchange in hemolytic uremic syndrome with cortical necrosis associated with IgAN.
Collapse
Affiliation(s)
- P Doddi
- Department of Nephrology, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - K Gowda
- Department of Histopathology, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - R Ramachandran
- Department of Nephrology, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - R Nada
- Department of Histopathology, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - V Kumar
- Department of Nephrology, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - M Rathi
- Department of Nephrology, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - H S Kohli
- Department of Nephrology, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - K L Gupta
- Department of Nephrology, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| |
Collapse
|
7
|
Noris M, Mele C, Remuzzi G. Podocyte dysfunction in atypical haemolytic uraemic syndrome. Nat Rev Nephrol 2015; 11:245-52. [PMID: 25599621 DOI: 10.1038/nrneph.2014.250] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Genetic or autoimmune defects that lead to dysregulation of the alternative pathway of complement have been associated with the development of atypical haemolytic uraemic syndrome (aHUS), which is characterized by thrombocytopenia, haemolytic anaemia and acute kidney injury. The relationship between aHUS, podocyte dysfunction and the resultant proteinuria has not been adequately investigated. However, the report of mutations in diacylglycerol kinase ε (DGKE) as a cause of recessive infantile aHUS characterized by proteinuria, highlighted podocyte dysfunction as a potential complication of aHUS. DGKE deficiency was originally thought to trigger aHUS through pathogenetic mechanisms distinct from complement dysregulation; however, emerging findings suggest an interplay between DGKE and complement systems. Podocyte dysfunction with nephrotic-range proteinuria can also occur in forms of aHUS associated with genetic or autoimmune complement dysregulation without evidence of DGKE mutations. Furthermore, proteinuric glomerulonephritides can be complicated by aHUS, possibly as a consequence of podocyte dysfunction inducing endothelial injury and prothrombotic abnormalities.
Collapse
Affiliation(s)
- Marina Noris
- IRCCS Istituto di Ricerche Farmacologiche "Mario Negri", Clinical Research Centre for Rare Diseases "Aldo e Cele Daccò", Via Camozzi 3, 24020, Ranica, Bergamo, Italy
| | - Caterina Mele
- IRCCS Istituto di Ricerche Farmacologiche "Mario Negri", Clinical Research Centre for Rare Diseases "Aldo e Cele Daccò", Via Camozzi 3, 24020, Ranica, Bergamo, Italy
| | - Giuseppe Remuzzi
- IRCCS Istituto di Ricerche Farmacologiche "Mario Negri", Clinical Research Centre for Rare Diseases "Aldo e Cele Daccò", Via Camozzi 3, 24020, Ranica, Bergamo, Italy
| |
Collapse
|
8
|
Manenti L, Gnappi E, Vaglio A, Allegri L, Noris M, Bresin E, Pilato FP, Valoti E, Pasquali S, Buzio C. Atypical haemolytic uraemic syndrome with underlying glomerulopathies. A case series and a review of the literature. Nephrol Dial Transplant 2013; 28:2246-59. [DOI: 10.1093/ndt/gft220] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
9
|
Hemolytic-uremic syndrome, malignant hypertension and IgA nephropathy: successful treatment with plasma exchange therapy. Transfus Apher Sci 2012; 47:155-8. [PMID: 22892290 DOI: 10.1016/j.transci.2012.06.018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2011] [Accepted: 06/29/2012] [Indexed: 11/22/2022]
Abstract
A young patient with hemolytic-uremic syndrome and malignant hypertension with serious deterioration of renal function is described whose biopsy specimen showed additional IgA mesangial deposits. The patient responded to steroid treatment and to plasma exchange therapy without the need of hemodialysis sessions. In the following years, he achieved clinical remission and his blood pressure was in normal ranges without any further complications. IgA glomerulonephritis is rarely associated to hemolytic-uremic syndrome and malignant hypertension, with only a few previously described cases. We present an overview of potential pathophysiological connections between these diseases.
Collapse
|
10
|
IgA nephropathy associated with a novel N-terminal mutation in factor H. Eur J Pediatr 2011; 170:107-10. [PMID: 20734203 DOI: 10.1007/s00431-010-1279-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2010] [Accepted: 08/12/2010] [Indexed: 01/21/2023]
Abstract
Most patients with IgA nephropathy exhibit complement deposition in the glomerular mesangium. Certain cases of IgA nephropathy have been associated with reduced levels of complement factor H. A recent study could not demonstrate mutations at the C-terminal of factor H. We describe a novel heterozygous mutation in factor H, position A48S (nucleotide position 142 G > T, alanine > serine), detected in exon 2 of a 14-year-old girl with IgA nephropathy. The patient exhibited reduced levels of C3 and factor H, the latter suggesting that the mutation affected factor H secretion. The patient developed initial signs and symptoms of glomerulonephritis at the age of 9 years but presented again at the age of 14 years with weight gain, renal failure, nephrotic-range proteinuria and malignant hypertension. Blood tests suggested the development of microangiopathic hemolytic anemia (MAHA) but the renal biopsy was mostly indicative of chronic changes associated with IgA nephropathy as well as vascular changes associated with malignant hypertension. Immunofluorescence exhibited deposits of IgA, C3, and IgM. Screening of the factor H gene revealed, in addition to the mutation, three heterozygous hemolytic uremic syndrome -associated risk polymorphisms (-257 c/t, 2089 a/g, and 2881 g/t) which may have increased the patient's susceptibility to the occurrence of MAHA triggered by malignant hypertension. The combined clinical picture of IgA nephropathy and MAHA may have been partly related to the alterations in factor H.
Collapse
|
11
|
Rockx MA, Gibson IW, Reslerova M. An unusual cause of acute renal failure in sickle cell disease. NDT Plus 2009; 2:376-8. [PMID: 25949348 PMCID: PMC4421385 DOI: 10.1093/ndtplus/sfp081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2009] [Accepted: 06/16/2009] [Indexed: 12/03/2022] Open
Abstract
A young female with sickle cell disease was treated for biopsy-proven IgA nephropathy. Serum creatinine levels resolved to normal range, but a year later, she presented with oedema, hypertension and acute renal failure. A repeat renal biopsy showed acute-on-chronic thrombotic microangiopathy (TMA). We suggest that circulating microparticles could be a pathophysiological link between sickle cell disease and the development of renal TMA. This case emphasizes the importance of a further biopsy for acutely declining renal function, even when a definite diagnosis has been made from a previous biopsy.
Collapse
Affiliation(s)
| | - Ian W Gibson
- Department of Pathology , University of Manitoba , Winnipeg, Manitoba , Canada
| | | |
Collapse
|
12
|
Somers MJG, Sharma A, Grant PE, Guimaraes AR, Schneeberger EE. Case records of the Massachusetts General Hospital. Case 23-2009. A 13-year-old boy with headache, nausea, seizures, and hypertension. N Engl J Med 2009; 361:389-400. [PMID: 19625720 DOI: 10.1056/nejmcpc0900640] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
13
|
Edey M, Strain L, Ward R, Ahmed S, Thomas T, Goodship THJ. Is complement factor H a susceptibility factor for IgA nephropathy? Mol Immunol 2009; 46:1405-8. [PMID: 19162324 DOI: 10.1016/j.molimm.2008.12.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2008] [Accepted: 12/08/2008] [Indexed: 11/18/2022]
Abstract
There is substantial evidence to suggest that complement activation plays a pivotal role in the pathogenesis of IgA nephropathy. Mesangial C3 deposition is seen in approximately 90% of patients and polymeric IgA has been shown to activate the alternative and lectin pathways. In addition there have been reports of deficiency and mutations in the serum complement regulator factor H (CFH) in association with IgA nephropathy. In this study we have examined the hypothesis that CFH is a susceptibility factor for IgA nephropathy. In 46 IgA nephropathy patients we undertook genotyping of three CFH SNPS (rs3753394, rs3753396 and rs1065489). There was no significant difference in the allele frequency of these 3 SNPs between the patients and normal controls. In the same group of patients we undertook mutation screening of CFH exons 18-23 using direct sequencing and found no abnormalities. All the patients had a normal serum factor H concentration. In this small cohort of IgA nephropathy patients we have not found evidence to support the hypothesis that factor H is a major susceptibility factor for the disease.
Collapse
Affiliation(s)
- Matthew Edey
- Institute of Human Genetics, Newcastle University, Newcastle upon Tyne, UK
| | | | | | | | | | | |
Collapse
|
14
|
Besbas N, Karpman D, Landau D, Loirat C, Proesmans W, Remuzzi G, Rizzoni G, Taylor CM, Van de Kar N, Zimmerhackl LB. A classification of hemolytic uremic syndrome and thrombotic thrombocytopenic purpura and related disorders. Kidney Int 2006; 70:423-31. [PMID: 16775594 DOI: 10.1038/sj.ki.5001581] [Citation(s) in RCA: 216] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The diagnostic terms hemolytic uremic syndrome (HUS) and thrombotic thrombocytopenic purpura (TTP) are based on historical and overlapping clinical descriptions. Advances in understanding some of the causes of the syndrome now permit many patients to be classified according to etiology. The increased precision of a diagnosis based on causation is important for considering logical approaches to treatment and prognosis. It is also essential for research. We propose a classification that accommodates both a current understanding of causation (level 1) and clinical association in cases for whom cause of disease is unclear (level 2). We tested the classification in a pediatric disease registry of HUS. The revised classification is a stimulus to comprehensive investigation of all cases of HUS and TTP and is expected to increase the proportion of cases in whom a level 1 etiological diagnosis is confirmed.
Collapse
Affiliation(s)
- N Besbas
- Hacettep University, Ankara, Turkey
| | | | | | | | | | | | | | | | | | | |
Collapse
|
15
|
von Baeyer H. Plasmapheresis in thrombotic microangiopathy-associated syndromes: review of outcome data derived from clinical trials and open studies. Ther Apher Dial 2002; 6:320-8. [PMID: 12164804 DOI: 10.1046/j.1526-0968.2002.00390.x] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Current reimbursement policy of health insurance for therapeutic plasmapheresis requires proof of efficacy using the concept of evidence-based medicine. The aim of this paper is to review the outcome of plasmapheresis used to treat thrombotic microangiopathy (TMA)-associated syndromes in the last decade to provide scientific evidence to back up reimbursement applications. The strength of evidence of each reviewed study was assessed using the five levels of evidence criteria as defined by the American Society of Hematology in 1996 for assessment of the treatment of immune thrombocytopenia. The level Experimental indication was added for situations where only case reports or small series supported by pathophysiological reasoning are available. The definitions of evidence used in this paper are as follows: Level I, randomized clinical trial with low rates of error (p < 0.01); Level II, randomized clinical trial with high rates of error (p < 0.05); Level III, nonrandomized studies with concurrent control group; Level IV, nonrandomized studies with historical control group; Level V, case series without a control group or expert opinion; and Experimental, case reports and pathophysiological reasoning. The results of this analysis based on the published data is summarized as follows: The indication of plasmapheresis is assigned to Level IV evidence for thrombotic thrombocytopenic purpura/hemolytic uremic syndrome (TTP/HUS); cancer/chemotherapy-associated TTP/HUS is assigned to Level V evidence; and TTP/HUS refractory to standard plasma exchange and post-bone marrow transplantation TTP/HUS are assigned to Experimental indication. For both subsets, protein A immunoadsorption is reportedly successful. The other TMA-associated syndromes, hemolysis elevated liver enzymes low platelets and HUS in early childhood, are no indication of plasmapheresis. Two randomized clinical trials were performed in order to demonstrate the superiority of plasma exchange/fresh frozen plasma (PEX/FFP) over plasma transfusion in the management of TTP/HUS. The results prove the greater clinical success of the latter type of plasma administration. Standard PEX/FFP has reduced the mortality of TTP/HUS from 94.5% to 13%.
Collapse
|