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Wightman A, Filler G, Díaz-González de Ferris ME. The urgent need for conducting clinical trials in pediatric nephrology globally. Pediatr Nephrol 2023; 38:2499-2506. [PMID: 36738331 DOI: 10.1007/s00467-023-05877-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 12/27/2022] [Accepted: 01/02/2023] [Indexed: 02/05/2023]
Affiliation(s)
- Aaron Wightman
- Department of Pediatrics, Divisions of Nephrology, Bioethics and Palliative Care, University of Washington School of Medicine, Seattle, WA, USA
| | - Guido Filler
- Department of Pediatrics, Schulich School of Medicine & Dentistry, Western University, London, ON, N6A 5W9, Canada
- Department of Pathology and Laboratory Medicine, Schulich School of Medicine & Dentistry, Western University, London, ON, N5A 5A5, Canada
- Department of Medicine, Schulich School of Medicine & Dentistry, Western University, London, ON, N6A 5W9, Canada
- The Lilibeth Caberto Kidney Clinical Research Unit, London Health Sciences Centre, London, ON, Canada
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2
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Hanna RM, Henriksen K, Kalantar-Zadeh K, Ferrey A, Burwick R, Jhaveri KD. Thrombotic Microangiopathy Syndromes-Common Ground and Distinct Frontiers. Adv Chronic Kidney Dis 2022; 29:149-160.e1. [PMID: 35817522 DOI: 10.1053/j.ackd.2021.11.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 11/02/2021] [Accepted: 11/18/2021] [Indexed: 11/11/2022]
Abstract
Thrombotic microangiopathies (TMAs) have in common a terminal phenotype of microangiopathic hemolytic anemia with end-organ dysfunction. Thrombotic thrombocytopenic purpura results from von Willebrand factor multimerization, Shiga toxin-mediated hemolytic uremic syndrome causes toxin-induced endothelial dysfunction, while atypical hemolytic uremic syndrome results from complement system dysregulation. Drug-induced TMA, rheumatological disease-induced TMA, and renal-limited TMA exist in an intermediate space that represents secondary complement activation and may overlap with atypical hemolytic uremic syndrome clinically. The existence of TMA without microangiopathic hemolytic features, renal-limited TMA, represents an undiscovered syndrome that responds incompletely and inconsistently to complement blockade. Hematopoietic stem cell transplant-TMA represents another more resistant form of TMA with different therapeutic needs and clinical course. It has become apparent that TMA syndromes are an emerging field in nephrology, rheumatology, and hematology. Much work remains in genetics, molecular biology, and therapeutics to unravel the puzzle of the relationships and distinctions apparent between the different subclasses of TMA syndromes.
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Affiliation(s)
- Ramy M Hanna
- UCI Medical Center Department of Medicine, Division of Nephrology, University of California Irvine, Orange, CA.
| | - Kammi Henriksen
- Department of Pathology, University of Chicago Medical Center, Chicago, IL
| | - Kamyar Kalantar-Zadeh
- UCI Medical Center Department of Medicine, Division of Nephrology, University of California Irvine, Orange, CA
| | - Antoney Ferrey
- UCI Medical Center Department of Medicine, Division of Nephrology, University of California Irvine, Orange, CA
| | - Richard Burwick
- Department of Obstetrics and Gynecology, Maternal-Fetal Medicine, Cedars Sinai Medical Center, Los Angeles, CA
| | - Kenar D Jhaveri
- Glomerular Disease Center at Northwell Health, Division of Kidney Diseases and Hypertension, Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Great Neck, NY
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Monet-Didailler C, Chevallier A, Godron-Dubrasquet A, Allard L, Delmas Y, Contin-Bordes C, Brissaud O, Llanas B, Harambat J. Outcome of children with Shiga toxin-associated haemolytic uraemic syndrome treated with eculizumab: a matched cohort study. Nephrol Dial Transplant 2021; 35:2147-2153. [PMID: 31411695 DOI: 10.1093/ndt/gfz158] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Accepted: 06/27/2019] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Treatment with eculizumab in Shiga toxin-associated haemolytic and uraemic syndrome (STEC-HUS) remains controversial despite its increasing utilization. The aim of our study was to evaluate the outcomes of children treated with eculizumab for STEC-HUS in a single-centre matched cohort study. METHODS Data were retrospectively collected from medical records of children diagnosed with STEC-HUS. The outcomes of patients treated with eculizumab for STEC-HUS were compared with those of a control group of untreated patients matched for age, sex and severity of acute kidney injury with a 1:2 matching scheme. RESULTS Eighteen children (median age 40.6 months) with STEC-HUS treated with eculizumab were compared with 36 matched control patients (median age 36.4 months) who did not receive eculizumab. All patients survived in the two groups. Within 1 month of HUS onset, the evolution of haematological and renal parameters did not differ between the two groups. At 12 months of follow-up, renal outcome was not significantly different between the two groups. At the last follow-up, the prevalence of decreased glomerular filtration rate in the eculizumab group (27%) was not statistically different from that in controls (38%), as was the prevalence of proteinuria and high blood pressure. Children who received eculizumab more often had extrarenal sequelae during follow-up. Eculizumab treatment appeared to be safe in children with STEC-HUS. CONCLUSION The benefit of eculizumab on renal and extrarenal outcomes in STEC-HUS could not be established based on our findings. However, efficacy and safety are not best assessed by the observational design and small sample size of our study. Randomized controlled trials are thus required to determine the efficacy of eculizumab in this indication.
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Affiliation(s)
- Catherine Monet-Didailler
- Service de Pédiatrie, Unité de Néphrologie, Centre de référence Maladies Rénales Rares du Sud-ouest, Centre Hospitalier Universitaire de Bordeaux, Bordeaux, France
| | - Audrey Chevallier
- Service de Pédiatrie, Unité de Néphrologie, Centre de référence Maladies Rénales Rares du Sud-ouest, Centre Hospitalier Universitaire de Bordeaux, Bordeaux, France
| | - Astrid Godron-Dubrasquet
- Service de Pédiatrie, Unité de Néphrologie, Centre de référence Maladies Rénales Rares du Sud-ouest, Centre Hospitalier Universitaire de Bordeaux, Bordeaux, France
| | - Lise Allard
- Service de Pédiatrie, Unité de Néphrologie, Centre de référence Maladies Rénales Rares du Sud-ouest, Centre Hospitalier Universitaire de Bordeaux, Bordeaux, France
| | - Yahsou Delmas
- Service de Néphrologie, Centre de référence Maladies Rénales Rares du Sud-ouest, Centre Hospitalier Universitaire de Bordeaux, Bordeaux, France
| | - Cécile Contin-Bordes
- Laboratoire d'Immunologie et Immunogénétique, Centre Hospitalier Universitaire de Bordeaux, Bordeaux, France
| | - Olivier Brissaud
- Service de Réanimation Pédiatrique, Centre Hospitalier Universitaire de Bordeaux, Bordeaux, France
| | - Brigitte Llanas
- Service de Pédiatrie, Unité de Néphrologie, Centre de référence Maladies Rénales Rares du Sud-ouest, Centre Hospitalier Universitaire de Bordeaux, Bordeaux, France
| | - Jérôme Harambat
- Service de Pédiatrie, Unité de Néphrologie, Centre de référence Maladies Rénales Rares du Sud-ouest, Centre Hospitalier Universitaire de Bordeaux, Bordeaux, France.,Université de Bordeaux, Inserm, Bordeaux Population Health Research Center, UMR 1219, Bordeaux, France
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Yesilbas O, Yozgat CY, Akinci N, Sonmez S, Tekin E, Talebazadeh F, Jafarov U, Temur HO, Yozgat Y. Acute Myocarditis and Eculizumab Caused Severe Cholestasis in a 17-Month-Old Child Who Has Hemolytic Uremic Syndrome Associated with Shiga Toxin-Producing Escherichia coli. J Pediatr Intensive Care 2020; 10:216-220. [PMID: 34395040 DOI: 10.1055/s-0040-1713111] [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: 02/14/2020] [Accepted: 05/02/2020] [Indexed: 10/23/2022] Open
Abstract
Cardiovascular involvement is uncommon in pediatric patients with hemolytic uremic syndrome associated with Shiga toxin-producing Escherichia coli (STEC-HUS). In this case report we presented a case of 17-month-old toddler who had a sporadic type of STEC-HUS complicated by acute myocarditis. The patient was successfully treated by a single dose of eculizumab after six doses of therapeutic plasma exchange (TPE) were inefficient to prevent the cardiac complication. Hepatotoxicity was observed after a single dose of eculizumab. Hepatic and cholestatic enzyme levels slowly returned to normal within 6 months. To the best of our knowledge, this is the first case of myocarditis/cardiomyopathy treated with eculizumab in STEC-HUS. This case illustrates the need for vigilance regarding myocardial involvement and eculizumab-induced hepatotoxicity in STEC-HUS.
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Affiliation(s)
- Osman Yesilbas
- Department of Pediatric Critical Care Medicine, Bezmialem Vakif University, Istanbul, Turkey
| | | | - Nurver Akinci
- Department of Pediatric Nephrology, Bezmialem Vakif University, Istanbul, Turkey
| | - Sirin Sonmez
- Department of Pediatrics, Bezmialem Vakif University, Istanbul, Turkey
| | - Eser Tekin
- Department of Pediatrics, Bezmialem Vakif University, Istanbul, Turkey
| | - Faraz Talebazadeh
- Department of Pediatrics, Bezmialem Vakif University, Istanbul, Turkey
| | - Uzeyir Jafarov
- Department of Pediatrics, Bezmialem Vakif University, Istanbul, Turkey
| | - Hafize Otcu Temur
- Department of Radiology, Bezmialem Vakif University, Istanbul, Turkey
| | - Yilmaz Yozgat
- Department of Pediatric Cardiology, Bezmialem Vakif University, Istanbul, Turkey
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Valid Presumption of Shiga Toxin-Mediated Damage of Developing Erythrocytes in EHEC-Associated Hemolytic Uremic Syndrome. Toxins (Basel) 2020; 12:toxins12060373. [PMID: 32512916 PMCID: PMC7354503 DOI: 10.3390/toxins12060373] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 06/02/2020] [Accepted: 06/03/2020] [Indexed: 02/06/2023] Open
Abstract
The global emergence of clinical diseases caused by enterohemorrhagic Escherichia coli (EHEC) is an issue of great concern. EHEC release Shiga toxins (Stxs) as their key virulence factors, and investigations on the cell-damaging mechanisms toward target cells are inevitable for the development of novel mitigation strategies. Stx-mediated hemolytic uremic syndrome (HUS), characterized by the triad of microangiopathic hemolytic anemia, thrombocytopenia, and acute renal injury, is the most severe outcome of an EHEC infection. Hemolytic anemia during HUS is defined as the loss of erythrocytes by mechanical disruption when passing through narrowed microvessels. The formation of thrombi in the microvasculature is considered an indirect effect of Stx-mediated injury mainly of the renal microvascular endothelial cells, resulting in obstructions of vessels. In this review, we summarize and discuss recent data providing evidence that HUS-associated hemolytic anemia may arise not only from intravascular rupture of erythrocytes, but also from the extravascular impairment of erythropoiesis, the development of red blood cells in the bone marrow, via direct Stx-mediated damage of maturing erythrocytes, leading to “non-hemolytic” anemia.
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Çelakil ME, Yücel BB, Bek K. CFH and CFB mutations in Shiga toxin-associated haemolytic uraemic syndrome in a 6-year-old boy. Paediatr Int Child Health 2020; 40:129-131. [PMID: 31242818 DOI: 10.1080/20469047.2019.1616458] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Haemolytic uraemic syndrome (HUS) is most commonly associated with Shiga toxin-producing Escherichia coli (STEC) while the recurrent hereditary atypical (aHUS) form secondary to complement system control protein mutations is relatively rare. A 6-year-old boy with complement factor H (CFH) and factor B (CFB) mutations and a history of bloody diarrhoea and PCR positivity for Shiga toxin was initially diagnosed as STEC+HUS. Acute kidney injury resolved with Eculizumab but he remains with chronic renal failure. Although the exact role of STEC in the pathogenesis of aHUS in this patient is not certain, there seems to be a relationship. However, several issues remain to be explained including the effect of genetic and environmental factors in modifying susceptibility to develop aHUS in some patients following STEC infection.Abbreviations: aHUS: atypical haemolytic uraemic syndrome; ANA: anti-nuclear antibody; ANCA: anti-neutrophil cytoplasmic antibody; ASO: anti-streptolysin O; BUN: blood urea nitrogen; CFB: complement factor B; CFH: complement factor H; EHEC: enterohaemorrhagic Escherichia coli; MCP: membrane co-factor protein; PD: peritoneal dialysis; STEC: Shiga toxin-producing Escherichia coli; STX 1-2: Shiga toxins 1-2.
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Affiliation(s)
- Mehtap Ezel Çelakil
- Department of Pediatric Nephrology, Kocaeli University Faculty of Medicine, Kocaeli, Turkey
| | - Burcu Bozkaya Yücel
- Department of Pediatric Nephrology, Kocaeli University Faculty of Medicine, Kocaeli, Turkey
| | - Kenan Bek
- Department of Pediatric Nephrology, Kocaeli University Faculty of Medicine, Kocaeli, Turkey
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Yesilbas O, Yozgat CY, Akinci N, Talebazadeh F, Jafarov U, Guney AZ, Temur HO, Yozgat Y. Sudden Cardiac Arrest and Malignant Ventricular Tachycardia in an 8-Year-Old Pediatric Patient Who Has Hemolytic Uremic Syndrome Associated with Shiga Toxin-Producing Escherichia coli. J Pediatr Intensive Care 2020; 9:290-294. [PMID: 33133747 DOI: 10.1055/s-0040-1708553] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2019] [Accepted: 02/16/2020] [Indexed: 10/24/2022] Open
Abstract
Gastrointestinal, neurological, pancreatic, hepatic, and cardiac dysfunction are extrarenal manifestations of hemolytic uremic syndrome associated with Shiga toxin-producing Escherichia coli (STEC-HUS). The most frequent cause of death for STEC-HUS is related to the central nervous system and cardiovascular system. Cardiac-origin deaths are predominantly related to thrombotic microangiopathy-induced ischemia and the immediate development of circulatory collapse. STEC-HUS cardiac related deaths in children are rare with only sporadic cases reported. In our literature search, we did not come across any pediatric case report about STEC-HUS causing sudden cardiac arrest and malignant ventricular tachycardia (VT). Herein, we report the case of an 8-year-old female child with a typical clinical manifestation of STEC-HUS. On the seventh day of pediatric intensive care unit admission, the patient had a sudden cardiac arrest, requiring resuscitation for 10 minutes. The patient had return of spontaneous circulation with severe monomorphic pulsed malignant VT. Intravenous treatment with lidocaine, amiodarone and magnesium sulfate were promptly initiated, and we administered multiple synchronized cardioversions, but VT persisted. Furthermore, we were not able to ameliorate her refractory circulation insufficiency by advanced cardiopulmonary resuscitation. Thus, inevitably, the patient lost her life. This case illustrates the need for aggressive management and the dilemma that pediatric critical care specialists, cardiologists, and nephrologists have to face when dealing with STEC-HUS that is worsened by a sudden cardiac arrest accompanied with VT.
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Affiliation(s)
- Osman Yesilbas
- Department of Pediatric Critical Care Medicine, Bezmialem Vakif University, Istanbul, Turkey
| | | | - Nurver Akinci
- Department of Pediatric Nephrology, Bezmialem Vakif University, Istanbul, Turkey
| | - Faraz Talebazadeh
- Department of Pediatrics, Bezmialem Vakif University, Istanbul, Turkey
| | - Uzeyir Jafarov
- Department of Pediatrics, Bezmialem Vakif University, Istanbul, Turkey
| | | | - Hafize Otcu Temur
- Department of Radiology, Bezmialem Vakif University, Istanbul, Turkey
| | - Yilmaz Yozgat
- Department of Pediatric Cardiology, Bezmialem Vakif University, Istanbul, Turkey
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Aldridge M, Burke J. Follow-up of children with infection-associated haemolytic uraemic syndrome 1979-1995: Would eculizumab have improved prognosis? J Paediatr Child Health 2020; 56:577-580. [PMID: 31705764 DOI: 10.1111/jpc.14685] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 10/10/2019] [Accepted: 10/21/2019] [Indexed: 12/25/2022]
Abstract
The late outcome in 55 children with infection-mediated haemolytic uremic syndrome (Shiga Toxin E Coli (STEC)-HUS and pneumococcal HUS) observed in 1979-1995 was followed up 23 years after disease onset. Of these, two were later confirmed to have atypical HUS (aHUS). Furthermore, of this population, five children had impaired kidney function at 3-months follow-up, which continued to deteriorate. These children had significant oliguria/anuria and hypertension during their illness requiring early dialysis and antihypertensive therapy. At 23 years post-disease onset, all five (100%) of these children have developed end-stage kidney disease or chronic kidney disease. Eculizumab is a monoclonal antibody that binds with high affinity to the C5 protein of the complement pathway, a major component of the pathophysiology of infection-mediated HUS. There are no long-term randomised controlled trials in the literature to support its use in such cases. Our 23-year follow-up of a population of severely affected children with infection-mediated HUS demonstrates a high percentage of chronic kidney disease and end-stage kidney disease (19%). Randomised controlled trials with eculizumab are now being conducted in this affected cohort.
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Affiliation(s)
- Melanie Aldridge
- Department of Nephrology, Queensland Children's Hospital, Brisbane, Queensland, Australia.,Faculty of Medicine, The University of Queensland, Brisbane, Queensland, Australia
| | - John Burke
- Department of Nephrology, Queensland Children's Hospital, Brisbane, Queensland, Australia
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Lingwood C. Verotoxin Receptor-Based Pathology and Therapies. Front Cell Infect Microbiol 2020; 10:123. [PMID: 32296648 PMCID: PMC7136409 DOI: 10.3389/fcimb.2020.00123] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Accepted: 03/05/2020] [Indexed: 12/22/2022] Open
Abstract
Verotoxin, VT (aka Shiga toxin,Stx) is produced by enterohemorrhagic E. coli (EHEC) and is the key pathogenic factor in EHEC-induced hemolytic uremic syndrome (eHUS-hemolytic anemia/thrombocytopenia/glomerular infarct) which can follow gastrointestinal EHEC infection, particularly in children. This AB5 subunit toxin family bind target cell globotriaosyl ceramide (Gb3), a glycosphingolipid (GSL) (aka CD77, pk blood group antigen) of the globoseries of neutral GSLs, initiating lipid raft-dependent plasma membrane Gb3 clustering, membrane curvature, invagination, scission, endosomal trafficking, and retrograde traffic via the TGN to the Golgi, and ER. In the ER, A/B subunits separate and the A subunit hijacks the ER reverse translocon (dislocon-used to eliminate misfolded proteins-ER associated degradation-ERAD) for cytosolic access. This property has been used to devise toxoid-based therapy to temporarily block ERAD and rescue the mutant phenotype of several genetic protein misfolding diseases. The A subunit avoids cytosolic proteosomal degradation, to block protein synthesis via its RNA glycanase activity. In humans, Gb3 is primarily expressed in the kidney, particularly in the glomerular endothelial cells. Here, Gb3 is in lipid rafts (more ordered membrane domains which accumulate GSLs/cholesterol) whereas renal tubular Gb3 is in the non-raft membrane fraction, explaining the basic pathology of eHUS (glomerular endothelial infarct). Females are more susceptible and this correlates with higher renal Gb3 expression. HUS can be associated with encephalopathy, more commonly following verotoxin 2 exposure. Gb3 is expressed in the microvasculature of the brain. All members of the VT family bind Gb3, but with varying affinity. VT2e (pig edema toxin) binds Gb4 preferentially. Verotoxin-specific therapeutics based on chemical analogs of Gb3, though effective in vitro, have failed in vivo. While some analogs are effective in animal models, there are no good rodent models of eHUS since Gb3 is not expressed in rodent glomeruli. However, the mouse mimics the neurological symptoms more closely and provides an excellent tool to assess therapeutics. In addition to direct cytotoxicity, other factors including VT–induced cytokine release and aberrant complement cascade, are now appreciated as important in eHUS. Based on atypical HUS therapy, treatment of eHUS patients with anticomplement antibodies has proven effective in some cases. A recent switch using stem cells to try to reverse, rather than prevent VT induced pathology may prove a more effective methodology.
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Affiliation(s)
- Clifford Lingwood
- Molecular Medicine, Research Institute, Hospital for Sick Children, Toronto, ON, Canada
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Atypical hemolytic uremic syndrome and complement blockade: established and emerging uses of complement inhibition. Curr Opin Nephrol Hypertens 2020; 28:278-287. [PMID: 30865166 DOI: 10.1097/mnh.0000000000000499] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
PURPOSE OF REVIEW Atypical hemolytic uremic syndrome (aHUS) is a diagnosis that has captured the interest of specialists across multiple fields. The hallmark features of aHUS are microangiopathic hemolysis and thrombocytopenia, which creates a diagnostic dilemma because of the occurrence of these findings in a wide variety of clinical disorders. RECENT FINDINGS In most of the instances, aHUS is a diagnosis of exclusion after ruling out causes such as Shigella toxin, acquired or genetic a disintegrin and metalloproteinase thrombospondin motif 13 deficiency (thrombotic thrombocytopenic purpura), and vitamin B12 deficiency. In the purest sense, aHUS is a genetic condition that is activated (or unmasked) by an environmental exposure. However, it is now evident that complement activation is a feature of many diseases. Variants in complement regulatory genes predispose to microangiopathic hemolysis in many rheumatologic, oncologic, and drug-induced vascular, obstetric, peritransplant, and infectious syndromes. SUMMARY Many 'hemolysis syndromes' overlap clinically with aHUS, and we review the literature on the treatment of these conditions with complement inhibition. New reports on the treatment of C3 glomerulopathy, Shiga toxin-related classic hemolytic uremic syndrome, and medication-related thrombotic microangiopathy will be reviewed as well.
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Abstract
The kidney harbours different types of endothelia, each with specific structural and functional characteristics. The glomerular endothelium, which is highly fenestrated and covered by a rich glycocalyx, participates in the sieving properties of the glomerular filtration barrier and in the maintenance of podocyte structure. The microvascular endothelium in peritubular capillaries, which is also fenestrated, transports reabsorbed components and participates in epithelial cell function. The endothelium of large and small vessels supports the renal vasculature. These renal endothelia are protected by regulators of thrombosis, inflammation and complement, but endothelial injury (for example, induced by toxins, antibodies, immune cells or inflammatory cytokines) or defects in factors that provide endothelial protection (for example, regulators of complement or angiogenesis) can lead to acute or chronic renal injury. Moreover, renal endothelial cells can transition towards a mesenchymal phenotype, favouring renal fibrosis and the development of chronic kidney disease. Thus, the renal endothelium is both a target and a driver of kidney and systemic cardiovascular complications. Emerging therapeutic strategies that target the renal endothelium may lead to improved outcomes for both rare and common renal diseases.
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El Qaidi S, Zhu C, McDonald P, Roy A, Maity PK, Rane D, Perera C, Hardwidge PR. High-Throughput Screening for Bacterial Glycosyltransferase Inhibitors. Front Cell Infect Microbiol 2018; 8:435. [PMID: 30619781 PMCID: PMC6305410 DOI: 10.3389/fcimb.2018.00435] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Accepted: 12/05/2018] [Indexed: 11/25/2022] Open
Abstract
The enteropathogenic and enterohemorrhagic Escherichia coli NleB proteins as well as the Salmonella enterica SseK proteins are type III secretion system effectors that function as glycosyltransferase enzymes to post-translationally modify host substrates on arginine residues. This modification is unusual because it occurs on the guanidinium groups of arginines, which are poor nucleophiles, and is distinct from the activity of the mammalian O-linked N-acetylglucosaminyltransferase. We conducted high-throughput screening assays to identify small molecules that inhibit NleB/SseK activity. Two compounds, 100066N and 102644N, both significantly inhibited NleB1, SseK1, and SseK2 activities. Addition of these compounds to cultured mammalian cells was sufficient to inhibit NleB1 glycosylation of the tumor necrosis factor receptor type 1-associated DEATH domain protein. These compounds were also capable of inhibiting Salmonella enterica strain ATCC 14028 replication in mouse macrophage-like cells. Neither inhibitor was significantly toxic to mammalian cells, nor showed in vitro cross-reactivity with the mammalian O-linked N-acetylglucosaminyltransferase. These compounds or derivatives generated from medicinal chemistry refinements may have utility as a potential alternative therapeutic strategy to antibiotics or as reagents to further the study of bacterial glycosyltransferases.
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Affiliation(s)
- Samir El Qaidi
- College of Veterinary Medicine, Kansas State University, Manhattan, KS, United States
| | - Congrui Zhu
- College of Veterinary Medicine, Kansas State University, Manhattan, KS, United States
| | - Peter McDonald
- High Throughput Screening Laboratory, University of Kansas, Lawrence, KS, United States
| | - Anuradha Roy
- High Throughput Screening Laboratory, University of Kansas, Lawrence, KS, United States
| | - Pradip Kumar Maity
- Synthetic Chemical Biology Core Laboratory, University of Kansas, Lawrence, KS, United States
| | - Digamber Rane
- Synthetic Chemical Biology Core Laboratory, University of Kansas, Lawrence, KS, United States
| | - Chamani Perera
- Synthetic Chemical Biology Core Laboratory, University of Kansas, Lawrence, KS, United States
| | - Philip R Hardwidge
- College of Veterinary Medicine, Kansas State University, Manhattan, KS, United States
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