Acta Clinica Belgica International Journal of Clinical and Laboratory Medicine ISSN: 1784-3286 (Print) 2295-3337 (Online) Journal homepage: http://www.tandfonline.com/loi/yacb20 Belgian consensus statement on the diagnosis and management of patients with atypical hemolytic uremic syndrome Kathleen J Claes, Annick Massart, Laure Collard, Laurent Weekers, Eric Goffin, Jean-Michel Pochet, Karin Dahan, Johann Morelle, Brigitte Adams, Nilufer Broeders, Patrick Stordeur, Daniel Abramowicz, Jean-Louis Bosmans, Koen Van Hoeck, Peter Janssens, Lissa Pipeleers, Patrick Peeters, Steven Van Laecke, Elena Levtchenko, Ben Sprangers, Lambertus van den Heuvel, Nathalie Godefroid & Johan Van de Walle To cite this article: Kathleen J Claes, Annick Massart, Laure Collard, Laurent Weekers, Eric Goffin, Jean-Michel Pochet, Karin Dahan, Johann Morelle, Brigitte Adams, Nilufer Broeders, Patrick Stordeur, Daniel Abramowicz, Jean-Louis Bosmans, Koen Van Hoeck, Peter Janssens, Lissa Pipeleers, Patrick Peeters, Steven Van Laecke, Elena Levtchenko, Ben Sprangers, Lambertus van den Heuvel, Nathalie Godefroid & Johan Van de Walle (2017): Belgian consensus statement on the diagnosis and management of patients with atypical hemolytic uremic syndrome, Acta Clinica Belgica, DOI: 10.1080/17843286.2017.1345185 To link to this article: http://dx.doi.org/10.1080/17843286.2017.1345185 Published online: 23 Oct 2017. Submit your article to this journal Article views: 13 View related articles View Crossmark data Full Terms & Conditions of access and use can be found at http://www.tandfonline.com/action/journalInformation?journalCode=yacb20 Download by: [UAE University] Date: 25 October 2017, At: 08:47 Acta Clinica Belgica, 2017 https://doi.org/10.1080/17843286.2017.1345185 REVIEW Belgian consensus statement on the diagnosis and management of patients with atypical hemolytic uremic syndrome Kathleen J Claesa,b , Annick Massartc , Laure Collardd , Laurent Weekerse , Eric Goffinf , Jean-Michel Pochetf , Karin Dahanf,g , Johann Morellef , Brigitte Adamsh , Nilufer Broedersc , Patrick Stordeuri , Daniel Abramowiczj, Jean-Louis Bosmansj , Koen Van Hoeckk, Peter Janssensl , Lissa Pipeleersl, Patrick Peetersm , Steven Van Laeckem , Elena Levtchenkon,o , Ben Sprangersa,b , Lambertus van den Heuvelo , Nathalie Godefroidp and Johan Van de Walleq Downloaded by [UAE University] at 08:47 25 October 2017 a Department of Nephrology and Renal Transplantation, University Hospitals Leuven, Leuven, Belgium; bLaboratory of Nephrology, Department of Microbiology and Immunology, KU Leuven, University of Leuven, Leuven, Belgium; cDepartment of Nephrology, Erasme University Hospital, Université Libre de Bruxelles, Brussels, Belgium; dDepartment of Pediatrics, CHU Liège, Liège, Belgium; eDepartment of Internal Medicine, Division of Nephrology, ULg, CHU Liège, Liège, Belgium; fDepartment of Nephrology, Cliniques Universitaires Saint-Luc, Université Catholique de Louvain, Brussels, Belgium; gInstitut de Génétique et de Pathologie, IPG, Gosselies, Belgium; hQueen Fabiola Children’s University Hospital, Brussels, Belgium; iImmunobiology Clinic, Erasme University Hospital, Université Libre de Bruxelles, Brussels, Belgium; jDepartment of Nephrology, University Hospital Antwerp, Antwerp, Belgium; kDepartment of Pediatrics, University Hospital Antwerp, Antwerp, Belgium; lDepartment of Nephrology and Hypertension, Universitair Ziekenhuis Brussels, Brussels, Belgium; m Department of Nephrology, University Hospital Ghent, Ghent, Belgium; nDepartment of Pediatric Nephrology, University Hospitals Leuven, Leuven, Belgium; oDepartment of Development and Regeneration, KU Leuven, Leuven, Belgium; pPediatric Department, Cliniques Universitaires Saint-Luc, Université Catholique de Louvain, Brussels, Belgium; qDepartment of Pediatric Nephrology, University Hospital Ghent, Ghent, Belgium KEYWORDS aHUS; diagnosis; management Introduction In the last decade, significant progress has been made in the understanding and the treatment of patients with atypical Hemolytic Uremic Syndrome (aHUS). aHUS has emerged as a disease largely caused by complement dysregulation. This facilitated the development of targeted therapy with the approval of a recombinant humanized IgG2/IgG4 monoclonal anti-C5 antibody (eculizumab) as major breakthrough. Until recently, treatment consisted of plasma exchange with variable and disappointing results. In prospective studies, the use of eculizumab has shown a fast and sustained control of the thrombotic microangiopathy (TMA) process. In January 2017, a protocol with recommendations for the diagnosis and treatment of patients with a (possible) diagnosis of atypical Hemolytic Uremic Syndrome was proposed. This protocol was developed by a Belgian working group consisting of clinicians, both adult and pediatric nephrologists, biologists and a geneticist working in university hospitals, with a particular interest and expertise in diagnosis and treatment of aHUS. The recent breakthroughs in diagnosis and treatment of aHUS urged us to address some highly relevant questions in the diagnostic and therapeutic field of aHUS. Therefore, the following text is a general consensus document on the diagnosis and the therapeutic approach of this disease. Since aHUS is an ultra-rare condition and randomized controlled trials are absent, evidence-based guidelines CONTACT Kathleen J Claes © Acta Clinica Belgica 2017 firstname.lastname@example.org cannot be provided. Consensus was reached on diagnostic approach, treatment duration in native aHUS and the use and duration of eculizumab as a preventive treatment in renal transplantation. The working group will have a meeting at least every year in order to update the diagnostic and treatment recommendations based on the last available scientific evidence and clinical experience. Definition and classification Atypical hemolytic uremic syndrome (aHUS) is an ultra-rare disease classified in the group of thrombotic microangiopathies (TMA). aHUS has an estimated prevalence of 2/106 adults and 3.3/106 children [1–3]. These conditions are characterized by the triad: Coombsnegative microangiopathic hemolytic anemia, thrombocytopenia and organ damage . The pathological features of the different forms of TMAs are identical: uncontrolled thrombosis at the arterioles and capillaries with consumption of thrombocytes, mechanical damage of erythrocytes and tissue ischemia . However, the underlying mechanisms starting this cascade differ. In the working group, we agreed to use the etiology-based classification of the various forms of TMA and to focus on diagnosis and treatment of aHUS. In this document, the following definition of aHUS is used: TMA caused by a dysregulation of the alternative pathway of the complement system. This definition is based on a Downloaded by [UAE University] at 08:47 25 October 2017 2 K. J. CLAES ET AL. Figure 1. Diagnostic and therapeutic approach of TMA (adapted from Campistol JM, Arias M et al) . recent consensus approach of atypical hemolytic uremic syndrome in children . HUS, triggered by underlying conditions, thrombotic thrombocytopenic purpura (TTP), and Shiga-like toxin producing Escherichia coli (STEC)-HUS are briefly discussed in the diagnosis and therapy section. Diagnosis of aHUS Clinical presentation Even though there is an increase in availability of diagnostic tests, aHUS remains mainly a clinical diagnosis because of our current inability to diagnose all patients either biochemically or by genetic testing. Therefore, the diagnosis is based on the combination of clinical judgment and biochemical testing. Furthermore, results of genetic testing are not immediately available. Despite the aforementioned difficulties in diagnosis, our understanding of the clinical characteristics has increased over the last decades. We are currently aware that aHUS can present in different ways. However, this further complicates the diagnostic process. The classical presentation with laboratory evidence of the classical triad of (Coombs-negative) hemolysis (decreased hemoglobin, elevated LDH, decreased haptoglobin, schistocytes on blood smear), thrombocytopenia and acute kidney injury is present in the overwhelming majority of patients. However, a subacute presentation can occur with proteinuria, acute kidney injury, arterial hypertension with signs of TMA on renal biopsy with or without thrombocytopenia and hemolysis. Therefore, in every patient presenting with renal insufficiency and lowgrade hemolysis the differential diagnosis with TMA needs to be considered. Furthermore, in more than 20% of patients extra-renal symptoms are present [5,7–9]. Neurological symptoms are the most common , but also cardiac (acute myocardial infarction, cardiomyopathy, heart failure), pulmonary, and gastrointestinal (diarrhea, colitis, abdominal pain, pancreatitis) involvement has been reported [10–14]. Figure 1 summarizes the diagnostic work-up. These diagnostic criteria are similar to the criteria defined in the UK by the aHUS rare disease group [7,15,16]. Firstly, thrombotic thrombocytopenic purpura (TTP) needs to be ruled out. TTP results from a severe deficiency in the metalloproteinase activity of the A Desintegrin and Downloaded by [UAE University] at 08:47 25 October 2017 ACTA CLINICA BELGICA Metalloproteinase with ThromboSpondin type 1 motif, member 13 (ADAMTS13). This can be either genetically or antibody-mediated. The genetic form is rare, constituting less than 5% of all TTP cases. Most adults present with the acquired form [17,18]. However, among certain groups such as newborn infants and young children, hereditary TTP may be more common than acquired TTP and during pregnancy, hereditary TTP may represent up to one-fourth of TTP cases [19,20]. The ADAMTS13 activity needs to be assessed. An ADAMTS 13 activity <10% confirms the diagnosis of TTP . Secondly, the majority of HUS cases in children are caused by a shigatoxin producing Escherichia Coli (STEC) enteric infection. STEC-HUS must be ruled out by stool culture, PCR for virulence genes and serologic studies . Finally, we need to look for environmental triggers causing TMA or aHUS as they might require specific management [3,22–29]. A non-exhaustive list of these conditions are described in the following remarks on Figure 1. Remarks on Figure 1: (1) ADAMTS 13 < 10%: TTP. If ADAMTS-13 < 10% the diagnosis of thrombotic thrombocytopenic purpura (TTP) is the most likely and further analyses are necessary to distinguish between genetically (rare) or antibody-mediated disease (e.g. primary or secondary, drug-induced forms for instance after clopidogrel/ticlopidine intake). (2) Shigatoxin-associated HUS: STEC/HUS: (a) Stool culture (rectal swab in the absence of stools) (b) PCR for STEC virulence genes in stool (c) Detection of E. Coli endotoxin serum antibodies (3) Underlying conditions triggering aHUS or causing TMA: a. Drug-induced TMA (DITMA): cisplatin; gemcitabine; mitomycin; clopidogrel; quinine; interferon α, β; anti-vascular endothelial growth factor therapy; alemtuzumab; calcineurin inhibitors; ciprofloxacin; mTOR inhibitors; oestrogens, Illicit drugs [e.g. cocaine, heroin, ecstasy, intravenous oxycodone]. www.ouhsc.edu/ platelets/DITMA.htm demonstrates a list with all published reports on DITMA. b. Transplantation: bone marrow transplantation and solid organ transplantation (may be promoted by drugs: Calcineurin inhibitor, mTOR inhibitors), antibody mediated rejection, infection (Cytomegalo virus infection) c. HELLP syndrome and pregnancy 3 d. Systemic diseases: systemic lupus erythematosus, antiphospholipid syndrome, scleroderma, vasculitis, malignancies e. Cobalamin C deficiency f. DGKE (diacylglycerol kinase epsilon) mutation g. Malignant hypertension h. Infection: HIV, streptococcus pneumoniae, influenza,.. . In case of pneumococcus infection, Coombs test is generally positive due to the action of a bacterial neuraminidase on the erythrocyte membrane. This neuraminidase exposes the erythrocyte Thomsen–Friedenreich antigen (T antigen, CD176) to natural antibodies that in turn activate the classical pathway of the complement. i. Rare causes: glomerulonephritis (IgA nephropathy, C3 glomerulopathy, glomerulopathies associated with monoclonal gammopathies of uncertain significance, …) As indicated above, many conditions can cause TMA. However, we need to be aware that these conditions might be the triggering event for aHUS as well. In women, pregnancy, especially the post-partum period is a triggering factor for aHUS, as is the use of oral contraceptive agents. aHUS during pregnancy needs to be differentiated from HELLP syndrome which is a different condition. In case of insufficient response to treatment of the underlying condition or removal of the trigger, the diagnosis of aHUS and treatment with eculizumab needs to be reconsidered. Diagnosis of aHUS is challenging and is made by exclusion. Results of genetic testing are not immediately available and the absence of a mutation does not preclude the diagnosis of aHUS. However, the finding of a mutation or complement abnormalities are supportive. Biochemical and genetic analysis. Currently, complement gene mutations or factor H antibodies are identified in up to 70% of aHUS patients. Around 60% of patients are carriers of mutations in complement-regulating genes (CFH, MCP/ CD46, CFI, thrombomodulin) or in the components of C3-convertase, factor B and C3. Around 5–10% of patients develop anti-CFH antibodies targeted to the C-terminal region, mimicking the effect of factor H mutations. Anti-CFH antibodies are more prevalent in children. For an overview of the pathophysiology of the complement system in aHUS, we refer to the thorough review of Nester in Clinical Immunology . Table 1 summarizes the diagnostic tests recommended for the diagnosis of TMA, including specific tests for the various etiologies of TMA. Laboratories with recommendations for sample collection, can be found 4 K. J. CLAES ET AL. Table 1. Diagnostic tests. Downloaded by [UAE University] at 08:47 25 October 2017 Biochemical evaluation Confirm TMA Hemoglobin, thrombocytes, reticulocytes LDH-haptoglobin Blood smear: schistocytes Indirect Coombs/direct Coombs PT/aPTT/fibrinogen Detect shigatoxine producing e Coli (STEC) Culture of stool or rectal swab PCR for STEC virulence genes in stool Serology: serum (E Coli) en Yersinia antibodies (anti-LPS antibodies for prevalent serotypes) Detect ADAMTS-13 deficiency Von Willebrand protease activity Test underlying causes/triggers depending of the clinical presentation (1) Plasma homocystein (↑↑), vitamin B12 ± methionine (↓); organic acid urine (urine methyl malonic acid). Positive result: detect MMACHC mutation: congenital cobalamin C deficiency (2) HIV serology, pulmonary cultures, influenza (3) ANF (ANA)/anti dsDNA (Farr)/anti-centromere Ab /antiphospholipid antibodies (anticardiolopin IgG and IgM, anti B/lupus anticoagulant (4) Hemocultures (5) Pregnancy testing (6) Chest X-ray Complement testing All patients Antibodies factor H; Factor H; Factor I CH50 MAC (C5b-9) C3, C4; index C3d/C3 CD46 expression on leucocytes (poly- or mononuclear leucocytes using a FACS test) Spare samples for freezing (cfr infra) for further diagnostics (−80°C) On indication Factor B, factor Bb, C3 convertase, Factor H activity, antibodies factor I,other complement factors, AP50 Extra sampling Eculizumab dosing and C5-eculizumab binding Genetic testing Complement factor H (CFH) Complement factor I (CFI) Membrane cofactor protein (MCP) Complement factor B (CFB) Complement C3 Complement Factor H related proteins (CFHR) CFH-CFHR hybrid gen DGKE mutation: if indicated Thrombomodulin (THBD) ADAMTS13-gen: if indicated MMACHC gen: if indicated to exclude defect in cobalamin deficiency Other complement genes: if indicated in Table 2 and on the website of the Belgian Society of Nephrology (www.bvn-sbn.be). Firstly, ADAMTS13 activity needs to be assessed given the therapeutic implications. An ADAMTS 13 activity < 10% confirms the diagnosis of TTP. Secondly, to exclude STEC-HUS, stool culture, PCR for virulence genes and antibody detection will be performed. The laboratory result that must be available before the onset of treatment with eculizumab is ADAMTS13 activity. However, blood samples not collected before the onset of plasmatherapy compromise further test interpretation. Because of lack of reimbursement at this time for all of the complement testing, we suggest to start with a limited number of complement testing which can be expanded to specific complement testing depending on the clinical presentation and the results of the first analyses. Testing of the complement system, both biochemically as genetically, is important because of its role in the evaluation of the prognosis (see therapeutic section). Treatment of aHUS Before the introduction of eculizumab, patients with aHUS were treated with plasma exchange with variable outcomes. As stated before, the prognosis is dependent on the genetic mutation found. The complement abnormality determines the prognosis for both end stage renal disease (ESRD) and recurrence of the disease after transplantation. The most important recent advance in the care of patients with aHUS was the regulatory approval in 2011 of a ‘first-in-class’ anti-complement therapeutic named eculizumab (Soliris). Eculizumab is a recombinant humanized monoclonal antibody directed against C5 that impedes its cleavage into C5a and C5b . The current treatment scheme consists of an induction and maintenance phase. The initial phase consists of four weekly doses and the maintenance phase of one dose every two weeks. This dose is depending on body weight (<40 kg) in children and fixed in patients weighing more than 40 kg. Treatment with eculizumab is efficient. However, many questions around the use, dosage, and duration of therapy with eculizumab remain unresolved and the cost is very high Data concerning long-term follow-up, pharmacokinetic variability, individualized treatment regimens, as well as the possibility to stop treatment (and in which subtypes) are limited. The recommendations for treatment proposed in this article are based on current literature (up to date till December 2016). Therapeutic approach TTP and other causes Figure 1 briefly describes the therapeutic approaches suggested for the diagnosis of TTP and underlying causes of aHUS. When ADAMTS13 activity is lower than 10% the diagnosis of TTP can be made and continuation of plasma exchange is mandatory with the rapid initiation of corticosteroids in acquired TTP . In refractory cases, second-line treatment with immunosuppressive therapy (intensification of plasma exchange, higher doses of glucocorticosteroids, rituximab, and bortezomib) or in the future dedicated monoclonal antibodies can be considered [32–34]. Further treatment depends on both the etiology and the response to treatment with plasma exchange and is beyond the scope of these guidelines. For the indication for plasma exchange in treatment of HUS triggered by drugs, we refer to the recommendation text from the American Society of apheresis . In STEC-HUS, early aggressive hydration has a renal protective role and the benefit of plasma exchange is uncertain [36,37]. Antibiotic treatment in STEC infections is not recommended since it increases the risk for ACTA CLINICA BELGICA 5 Downloaded by [UAE University] at 08:47 25 October 2017 Table 2. Sample collection and laboratories. TEST Classical pathway (CH 50) Alternative pathway (AP 50) Factor H concentration Factor H function Anti-factor H antibodya Factor I concentration C3Nef C3 C3d C4 C5 Factor B Factor Bb SC5b-9 complex (MAC) Paid by the patient or INAMI/RIZIV INAMI/RIZIV Not reimbursed INAMI/RIZIV Not reimbursed Not reimbursed INAMI/RIZIV Not reimbursed INAMI/RIZIV INAMI/RIZIV INAMI/RIZIV Not reimbursed Not reimbursed Not reimbursed Not reimbursed CD46 (MCP) INAMI/RIZIV ADAMTS 13 Not reimbursed Blood sample Serum: 5 ml whole blood From Monday to Friday, send at room temperature in the four hours that follow blood withdrawal, and in a such way that the samples arrive in the lab at the latest at 4 pm 5–10 ml EDTA whole blood or: centrifuge, collect and keep EDTA plasma, citrated plasma, and/or serum, each in three aliquots, at −20 °C for a few days, 5ml citrated whole blood or at −80 °C for a longer period, and send while keeping frozen 5 ml EDTA whole blood send and keep as such at room temperature 5 ml citrated whole blood As LPS antigen E.coli Enterohemorragis E.coli pcrHUS (faeces) INAMI/RIZIV INAMI/RIZIV 5 ml serum whole blood Faeces Genetic testing (gene/panel) INAMI/RIZIV 5–10 ml EDTA or extracted DNA Eculizumab c5-eculizumab complex Eculizumab inhibiting capacity Not reimbursed Not reimbursed Not reimbursed serum (5 ml whole blood) Laboratory and contact details LHUB-ULB Site Anderlecht (Hopital Erasme); Dr P Stordeur; Laboratoire d'Immunologie, 6ème étage; 808 route de Lennik, 1070 Bruxelles; Tel 02 555 3787/3862 ; e-mail: email@example.com. ac.be Available at several laboratories UZ Brussel; Prof. Dr. D. Piérard; Microbiologie en Ziekenhuishygiëne; Laarbeeklaan 101, 1090 Jette. Tel 02/47750000 IPG, prof. Dr. K Dahan; avenue Georges Lemaître 25, 6041 Gosselies. Tel 071/473047 centrifuge (2000 g, 10 min at Radboud UMC; Prof dr 4 °C) and freeze at −80 °C Wevers;Laboratoriumgeneeskunde 830 TML, Geert Groteplein zuid 10, 6525 GA Nijmegen; Tel 0031243614567; e-mail: secretariaat-TML.labgk@ radboudumc.nl a Anti-Factor H antibody: if requested alone, can be sent at room temperature, and kept for a week at 4 °C, or after separation, serum can be kept at −20 °C for a longer period. development of HUS . HUS associated with systemic disease and infections relies on the treatment of the underlying infection or disease. In malignant hypertension, aggressive antihypertensive treatment is in order and this usually leads to the rapid resolution of the TMA with partial or complete recovery of renal function . We recommend treatment with folinic acid, hydroxycobalamin, betain, and multidisciplinary follow-up by nephrologist, neurologist, and a metabolic expert for patients with cobalamin C deficiency. In non-renal transplant recipients, blood pressure control and adjustment of immunosuppressive treatment is recommended. In renal transplant recipients, antibody-mediated rejection and infection (CMV) need to be excluded and if present treated first. As indicated above, many of these conditions cause TMA. However, we need to be aware that these conditions might be the triggering events for aHUS. In case of insufficient response to treatment of the underlying condition or removal of the trigger, the diagnosis of aHUS needs to be reconsidered. Therapeutic approach for the first flare of aHUS Figure 1 demonstrates the consensus on treatment approach for the first flare of aHUS in adult patients. For children, earlier start of and first-line treatment with eculizumab might be indicated, because of the unacceptable high complication rate of plasmapheresis in a HUS children [6,40]. (1) Collection of blood samples immediately before plasma exchange. (2) Start with plasmapheresis 1–1.5 times plasma volume with substitution of FFP only or Octaplas® (3) Start request procedure for Soliris® (4) Plasma exchange frequency depending on treatment response (start 1 week daily, decrease in frequency in case of and depending on the treatment response). (5) Start Soliris®, after vaccination following the recommendations below a. in case of absence of treatment response after five consecutive days of plasma exchange. Absence of treatment response is defined as either the absence of normalization of platelet count or absence of signs of renal recovery , in patients without severe chronic damage on biopsy or renal imaging b. in case of hypersensitivity reactions to plasma despite pre-treatment with corticosteroids or Octaplas® use 6 K. J. CLAES ET AL. Table 3. Risk categories. Underlying abnormalities MCP/CD46 mutation Previously positive anti-CFH antibodies DGKE mutation Intermediate No high-risk mutation No mutation found or auto-antibodies Variant of unknown functional significance CFI mutation Detectable anti-CFH auto-antibodies High CFH mutation or gene re-arrangements involving factor H and factor H related proteins C3 mutation CFB mutation High risk due to recurrence in previous allograft Downloaded by [UAE University] at 08:47 25 October 2017 Risk classification Low c. in case of relapse in situation of reducing plasmapheresis frequency or in case of relapse after stopping plasmapheresis (6) Treatment monitoring: tests are summarized in Table 1. (7) After start of Soliris®: re-evaluation after six months will be done: if no disease activity is present in adult patients with normalization of hematological parameters and normalization/ stabilization of renal function, eculizumab will be stopped with close follow-up. The suggested follow-up frequency will be discussed in the following section. In case of treatment of aHUS in a patient with a MCP/CD46 mutation and complete recovery of renal function, treatment will be stopped at time of confirmation of this diagnosis. (8) In patients in need of renal replacement therapy at time of presentation, treatment with eculizumab can be started based on duration of ESRD and/or biopsy results. In case of no signs of recovery of renal function and/ or severe chronic signs on renal biopsy after four months : treatment with eculizumab will be stopped. (9) Treatment of aHUS caused by antibodies against factor H. In this case, there is need for immunosuppressive therapy. Eculizumab can be considered for this indication at the acute phase of TMA, as well in case of treatment resistance. We refer to the review of Blanc et al. on this item . Treatment for recurrent aHUS Treatment modalities of recurrent aHUS after withdrawal of eculizumab will be decided on a case by case basis. The decision needs to be based on the complement abnormalities and clinical response to treatment in the previous disease episodes. Prophylactic eculizumab No 3 months 6 months Duration decision case by case. Long-term treatment might be possible with yearly revision by the reimbursement college. Renal transplantation After transplantation, the risk of recurrence ranges from 20 to 70% depending on the mutation of the complement pathway. Furthermore, after transplantation, environmental factors such as ischemia/reperfusion injury, acute rejection, infection, and immunosuppressive drugs may act as a trigger for disease recurrence. In order to decrease these triggering factors, the working group proposes the following general recommendations: (1) Donor criteria: a. No DCD donor or donor with high risk of I/R injury. Cold ischemia time as short as possible b. Living-related donor: i. The mutation is known and definitively pathogenic and is not present in the donor: donation possible ii. No mutation is found or there is a variant with unknown functionality: contraindication for donation (2) Recipient management : a. Induction b. Avoid toxic levels of calcineurin inhibitors (CNI), avoid mTOR inhibitors c. Other immunosuppressive scheme: at center’s discretion d. Consider statin (protection of the endothelium) e. Avoid high blood pressure levels f. CMV prophylaxis in all risk groups (not if donor negative/receptor negative) g. Vaccination has to be completed before listing h. No ABO-incompatible renal transplantation and avoidance of donor-specific antibodies. The recent reimbursement criteria for prophylactic treatment of aHUS before renal transplantation allows the listing of patients with aHUS and high risk for disease recurrence. We will use a standardized protocol to Downloaded by [UAE University] at 08:47 25 October 2017 ACTA CLINICA BELGICA 7 define the indication and the duration of eculizumab as prophylactic treatment to prevent recurrence after transplantation. The risk of recurrence is dependent on the defect responsible for aHUS. For patients with no identifiable mutation, the recurrence risk is more difficult to assess. In these recommendations, we stratified the risk of recurrence in three levels, (based on data by Zuber and co-workers and the UK guidelines) [15,45]. The risk stratification is based on genetic screening, presence of auto-antibodies, and previous transplant history. Recurrence risk is the highest in the immediate post-transplant period and in the first year after transplantation. This recurrence risk decreases significantly after the second year . Therefore, we propose to withdraw treatment in patients and chose to limit the duration of the therapy with close monitoring of the patients after withdrawal of treatment. In low risk patients, no prophylaxis will be given, whereas in intermediate and in high-risk patients, prophylactic treatment will be given for, respectively, 3 and 6 months. In case of recurrence in previous allograft with graft loss due to the recurrence, duration of treatment will be decided based on a case by case basis. Long-term treatment is possible with yearly revision in the reimbursement college (Table 3). Nimenrix® or Menveo® (ideally, at least two weeks before treatment and before activation on the transplant waiting list). Booster after 8–12 w. Booster after three years and subsequent doses every five years. Bexsero®: a vaccine against serotype B is currently available in Belgium but not reimbursed. A second vaccine (Trumenba®) is in clinical development and registration at EMA is introduced. Pneumococcal vaccination: In children >5 years old and in adults: Prevenar® 13, 2 months later Pneumo 23®. Pneumo 23® booster after 5 years. Hemophilus influenzae: children and adults: 1 dose act-HIB Antibiotic prophylaxis during treatment in adult patients: Antibiotic prophylaxis during treatment in adult patients: We recommend prophylactic treatment with azithromycine until 60 days after stop eculizumab in all patients. We chose treatment with azithromycine over quinolones because of its narrower spectrum and the risk of tendon lesions with quinolones in this patient population. In children, antibiotic prophylaxis is recommended as well with antibiotic choice and duration at centers discretion. Liver and kidney transplantation Eculizumab dose The current treatment scheme consists of an induction and maintenance phase with doses based on body weight for children (<40 kg). The initial phase consists of four weekly doses and the maintenance phase of one dose every two weeks. This dose is depending on body weight (<40 kg) in children, in the patients weighing more than 40 kg the dose is fixed to 900 mg in weekly doses for 4 weeks. A dose of 1200 mg is administered one week after the final dose of 900 mg and every two weeks thereafter. In the future combined liver and kidney transplantation with prophylactic eculizumab probably will represent a curative option in selected cases. In this setting, duration of therapy will be determined by recovery of function of the liver allograft. Treatment of patients with eculizumab Preparation of patients before treatment All patients should get a vaccination against meningococcal infection given the risk inherent to the treatment with eculizumab. However, the current vaccination scheme does not protect against all meningococcal serotypes and therefore we recommend to give prophylactic antibiotic treatment. Patients should be informed of the risk and signs of the meningococcal infection and that they must contact the treating center in any case of suspicion. The information brochure on meningococcal infection, patient safety card, and the contact details of the treating physician should be handed over. With regard to vaccination of the household close contacts: vaccination with tetravalent conjugated meningococcal vaccination needs to be considered since it interferes with carriership and transmission. The working group recommends the following scheme: Vaccination: Meningococcal vaccination with conjugated tetravalent meningococcal vaccine: Prophylactic treatment in the setting of renal transplantation  Adult patients should receive a single dose of 900 mg eculizumab which is completed prior to the start of surgery. The dose and dosing schedule should be adjusted for body weight in children as per pediatric dosing schedule. Adult patients should receive three further doses of 900 mg eculizumab at weekly intervals. A dose of 1200 mg is administered one week after the final dose of 900 mg and every two weeks thereafter. The dose and dosing schedule should be adjusted for body weight in children as per pediatric dosing schedule. Patient monitoring during treatment and after discontinuation of eculizumab treatment During the treatment, the monitoring consists of regular monitoring of CH50. In the future, it might be possible to monitor treatment by measuring specific complement activity, eculizumab levels, and binding [47,48]. Table 4 8 K. J. CLAES ET AL. Table 4. Monitoring after treatment cessation. Time since last Eculizumab dose Week 0 Monitoring Baseline: Hb, thrombocytes, LDH, urea, creatinine and electrolytes, bilirubin, haptoglobin Week 2–6 X2/wk Hb, thrombocytes, LDH, urea, creatinine and electrolytes, Weekly: schistocytes, bilirubin, haptoglobin Week 6–10 Weekly Hb, thrombocytes, LDH, urea, creatinine and electrolytes, schistocytes, bilirubin, haptoglobin After week 10 Every 14 days: Hb, thrombocytes, LDH, urea, creatinine and electrolytes, schistocytes, bilirubin, haptoglobin Home monitoring and every patient visit Proteinuria urine: dipstick Home monitoring and every patient visit Intensive blood pressure control In case of trigger (infection, high blood pressure, diarrhea and other intercurrent events) refer patient for monitoring and renal function recommends the monitoring schedule during and after stop of treatment, based on the UK guidelines . Downloaded by [UAE University] at 08:47 25 October 2017 Family counseling Patients should be informed about the possible heritability of the condition and offered genetic counseling by a geneticist. In case of a known pathogenic mutation, we do recommend routine familial screening in case of living-related donation. The screening is possible if the mutation is known pathogenic. If the potential living donor is not a carrier of the mutation, donation is possible. Contraception and pregnancy Women should be informed about the risk of recurrence after a pregnancy or following initiation of contraception containing estrogen. We recommend the use of contraception with prostagens only. This needs to be discussed with the treating gynecologist. As noted above, pregnancy is a triggering event for recurrence of aHUS. Currently, there are limited data on the safety of the use of eculizumab during pregnancy in patients with aHUS  but there is growing evidence of the safety of eculizumab in patients with paroxysmal nocturnal hemoglobinuria . We recommend that the patient is referred to a specialized center for counseling and pregnancy follow-up. We recommend that prophylactic treatment with eculizumab to be considered on a case by case base. Conclusion This text is a general consensus document. aHUS is an ultra-rare condition and the absence of randomized controlled trials makes it impossible to establish evidence-based guidelines. This implies that these advices are dynamic as well. Yearly or sooner in the case of new evidence, the working group will review the consensus document. Furthermore, each member of the group has the right to summon the working group in case he/she sees a binding reason. Disclosure statement Some of the members of the working group have received fees and support from Alexion Pharmaceuticals (KC, JVDW, AM, NB, JM, EL, PS, EG, PJ) or OMEROS (AM) either directly or through their respective employer. ORCID Kathleen J Claes http://orcid.org/0000-0001-8510-2345 Annick Massart http://orcid.org/0000-0002-6196-8555 Laure Collard http://orcid.org/0000-0003-3073-8201 Laurent Weekers http://orcid.org/0000-0002-3151-4640 Eric Goffin http://orcid.org/0000-0001-9242-7148 Jean-Michel Pochet http://orcid.org/0000-0001-6564-6740 Karin Dahan http://orcid.org/0000-0003-3036-7981 Johann Morelle http://orcid.org/0000-0002-6925-1989 Brigitte Adams http://orcid.org/0000-0001-9693-2205 Nilufer Broeders http://orcid.org/0000-0001-5377-9335 Patrick Stordeur http://orcid.org/0000-0001-5398-0709 Jean-Louis Bosmans http://orcid.org/0000-0001-7928-5675 Peter Janssens http://orcid.org/0000-0002-0981-8621 Patrick Peeters http://orcid.org/0000-0002-8046-300X Steven Van Laecke http://orcid.org/0000-0001-9700-5358 Elena Levtchenko http://orcid.org/0000-0002-8352-7312 Ben Sprangers http://orcid.org/0000-0003-1314-9675 Lambertus van den Heuvel http://orcid.org/0000-00033917-6727 Johan Van de Walle http://orcid.org/0000-0001-9700-5358 References  Taylor CM, Machin S, Wigmore SJ, et al. Clinical practice guidelines for the management of atypical haemolytic uraemic syndrome in the United Kingdom. Br J Haematol. 2010;148(1):37–47.  Zimmerhackl LB, Besbas N, Jungraithmayr T, et al. Epidemiology, clinical presentation, and pathophysiology of atypical and recurrent hemolytic uremic syndrome. Semin Thromb Hemost. 2006;32(2):113–120.  Noris M, Remuzzi G. Atypical hemolytic-uremic syndrome. N Engl J Med. 2009;361(17):1676–1687.  George JN, Nester CM. Syndromes of thrombotic microangiopathy. N Engl J Med. 2014;371(7):654–666.  Noris M, Bresin E, Mele C, et al. Atypical hemolyticuremic syndrome. In: Pagon RA, Adam MP, Ardinger HH, Wallace SE, Amemiya A, Bean LJH, Bird TD, Ledbetter N, Mefford HC, Smith RJH, Stephens Downloaded by [UAE University] at 08:47 25 October 2017 ACTA CLINICA BELGICA K, editors. GeneReviews® [Internet]. Seattle (WA): University of Washington; 1993–2017.  Loirat C, Fakhouri F, Ariceta G, et al. An international consensus approach to the management of atypical hemolytic uremic syndrome in children. Pediatr Nephrol. 2016;31(1):15–39.  Nester CM, Barbour T, de Cordoba SR, et al. Atypical aHUS: state of the art. Mol Immunol. 2015;67(1):31–42.  Ardissino G, Possenti I, Tel F, et al. Time to change the definition of hemolytic uremic syndrome. Eur J Intern Med. 2014;25(2):e29.  Sallee M, Ismail K, Fakhouri F, et al. Thrombocytopenia is not mandatory to diagnose haemolytic and uremic syndrome. BMC Nephrol. 2013;14:1126.  Fremeaux-Bacchi V, Fakhouri F, Garnier A, et al. Genetics and outcome of atypical hemolytic uremic syndrome: a nationwide french series comparing children and adults. Clin J Am Soc Nephrol. 2013;8(4):554–562.  Hu H, Nagra A, Haq MR, et al. Eculizumab in atypical haemolytic uraemic syndrome with severe cardiac and neurological involvement. Pediatr Nephrol. 2014;29(6):1103–1106.  Robitaille P, Gonthier M, Grignon A, et al. Pancreatic injury in the hemolytic-uremic syndrome. Pediatr Nephrol. 1997;11(5):631–632.  Oshima T, Ikutomi M, Shinohara H, et al. Acute myocardial infarction caused by thrombotic microangiopathy complicated with myelodysplastic syndrome. Int Heart J. 2016 Sep 13.  Patschan D, Witzke O, Duhrsen U, et al. Acute myocardial infarction in thrombotic microangiopathies–clinical characteristics, risk factors and outcome. Nephrol Dial Transplant. 2006;21(6):1549–1554.  Kavanagh D. The aHUS rare disease group. 2016. Available from: https://rarerenal.org  Goodship TH, Cook HT, Fakhouri F, et al. Atypical hemolytic uremic syndrome and C3 glomerulopathy: conclusions from a ‘Kidney Disease: Improving Global Outcomes’ (KDIGO) controversies conference. Kidney Int. 2016 Dec 15.  Furlan M, Robles R, Galbusera M, et al. von Willebrand Factor-cleaving protease in thrombotic thrombocytopenic purpura and the hemolytic-uremic syndrome. N Engl J Med. 1998;339(22):1578–1584.  Tsai HM, Lian EC. Antibodies to von Willebrand factorcleaving protease in acute thrombotic thrombocytopenic purpura. N Engl J Med. 1998;339(22):1585–1594.  Vieira-Martins P, El SC, Bordereau P, et al. Defining the genetics of thrombotic microangiopathies. Transfus Apher Sci. 2016;54(2):212–219.  Moatti-Cohen M, Garrec C, Wolf M, et al. Unexpected frequency of Upshaw-Schulman syndrome in pregnancy-onset thrombotic thrombocytopenic purpura. Blood. 2012;119(24):5888–5897.  Shah N, Rutherford C, Matevosyan K, et al. Role of ADAMTS13 in the management of thrombotic microangiopathies including thrombotic thrombocytopenic purpura (TTP). Br J Haematol. 2013;163(4):514–519.  Le QM, Lionet A, Kamar N, et al. Complement mutationassociated de novo thrombotic microangiopathy following kidney transplantation. Am J Transplant. 2008 Aug;8(8):1694–1701.  Zarifian A, Meleg-Smith S, O’donovan R, et al. Cyclosporine-associated thrombotic microangiopathy in renal allografts. Kidney Int. 1999;55(6):2457–2466. 9  Zeigler ZR, Shadduck RK, Nemunaitis J, et al. Bone marrow transplant-associated thrombotic microangiopathy: a case series. Bone Marrow Transplant. 1995 Feb;15(2):247–253.  Fakhouri F, Roumenina L, Provot F, et al. Pregnancyassociated hemolytic uremic syndrome revisited in the era of complement gene mutations. J Am Soc Nephrol. 2010;21(5):859–867.  Izzedine H, Perazella MA. Thrombotic microangiopathy, cancer, and cancer drugs. Am J Kidney Dis. 2015;66(5):857–868.  Nataatmadja M, Divi D. Relapsing thrombotic microangiopathy and intravenous sustained-release oxycodone. Clin Kidney J. 2016;9(4):580–582.  Loupiac A, Elayan A, Cailliez M, et al. Diagnosis of Streptococcus pneumoniae-associated hemolytic uremic syndrome. Pediatr Infect Dis J. 2013;32(10):1045–1049.  Available from: www.ouhsc.edu/platelets/DITMA.htm. 2016.  Legendre CM, Licht C, Muus P, et al. Terminal complement inhibitor eculizumab in atypical hemolyticuremic syndrome. N Engl J Med. 2013;368(23):2169– 2181.  Sayani FA, Abrams CS. How i treat refractory thrombotic thrombocytopenic purpura. Blood. 2015;125(25):3860–3867.  Patriquin CJ, Thomas MR, Dutt T, et al. Bortezomib in the treatment of refractory thrombotic thrombocytopenic purpura. Br J Haematol. 2016 Mar 24.  Scully M, McDonald V, Cavenagh J, et al. A phase 2 study of the safety and efficacy of rituximab with plasma exchange in acute acquired thrombotic thrombocytopenic purpura. Blood. 2011;118(7):1746– 1753.  Rock GA, Shumak KH, Buskard NA, et al. Comparison of plasma exchange with plasma infusion in the treatment of thrombotic thrombocytopenic purpura. Canadian Apheresis Study Group. N Engl J Med. 1991;325(6):393–397.  Schwartz J, Winters JL, Padmanabhan A, et al. Guidelines on the use of therapeutic apheresis in clinical practiceevidence-based approach from the writing committee of the American society for apheresis: the sixth special issue. J Clin Apher. 2013;28(3):145–284.  Ardissino G, Tel F, Possenti I, et al. Early volume expansion and outcomes of hemolytic uremic syndrome. Pediatrics. 2016 Jan;137(1):1–9.  Tarr PI, Gordon CA, Chandler WL. Shiga-toxinproducing Escherichia coli and haemolytic uraemic syndrome. Lancet. 2005 Mar 19;365(9464):1073–1086.  Freedman SB, Xie J, Neufeld MS, et al. Shiga toxinproducing escherichia coli infection, antibiotics, and risk of developing hemolytic uremic syndrome: a metaanalysis. Clin Infect Dis. 2016 May 15;62(10):1251–1258.  Asif A, Nayer A, Haas CS. Atypical hemolytic uremic syndrome in the setting of complement-amplifying conditions: case reports and a review of the evidence for treatment with eculizumab. J Nephrol. 2016 Nov;15:1–16.  Johnson S, Stojanovic J, Ariceta G, et al. An audit analysis of a guideline for the investigation and initial therapy of diarrhea negative (atypical) hemolytic uremic syndrome. Pediatr Nephrol. 2014 Oct;29(10):1967–1978.  Zuber J, Fakhouri F, Roumenina LT, et al. Use of eculizumab for atypical haemolytic uraemic syndrome and C3 glomerulopathies. Nat Rev Nephrol. 2012 Nov;8(11):643–657. 10 K. J. CLAES ET AL. Downloaded by [UAE University] at 08:47 25 October 2017  Povey H, Vundru R, Junglee N, et al. Renal recovery with eculizumab in atypical hemolytic uremic syndrome following prolonged dialysis. Clin Nephrol. 2014;82(11):326–331.  Blanc C, Togarsimalemath SK, Chauvet S, et al. Antifactor H autoantibodies in C3 glomerulopathies and in atypical hemolytic uremic syndrome: one target, two diseases. J Immunol. 2015;194(11):5129–5138.  Verhave JC, Westra D, van Hamersvelt HW, et al. Living kidney transplantation in adult patients with atypical haemolytic uraemic syndrome. Neth J Med 2013 Sep;71(7):342–347.  Zuber J, Le QM, Morris H, et al. Targeted strategies in the prevention and management of atypical HUS recurrence after kidney transplantation. Transplant Rev (Orlando). 2013;27(4):117–125.  Le QM, Zuber J, Moulin B, et al. Complement genes strongly predict recurrence and graft outcome in adult renal transplant recipients with atypical hemolytic and uremic syndrome. Am J Transplant. 2013 Mar;13(3):663–675.  Volokhina EB, Westra D, van der Velden TJ, et al. Complement activation patterns in atypical hemolytic uremic syndrome during acute phase and in remission. Clin Exp Immunol. 2014 Jul 31.  Volokhina EB, van de Kar NC, Bergseth G, et al. Sensitive, reliable and easy-performed laboratory monitoring of eculizumab therapy in atypical hemolytic uremic syndrome. Clin Immunol. 2015;160(2):237– 243.  Servais A, Devillard N, Fremeaux-Bacchi V, et al. Atypical haemolytic uraemic syndrome and pregnancy: outcome with ongoing eculizumab. Nephrol Dial Transplant. 2016;31(12):2122–2130.  Kelly RJ, Hochsmann B, Szer J, et al. Atypical haemolytic uraemic syndrome and pregnancy: outcome with ongoing eculizumab. Nephrol Dial Transplant. 2015;373(11):1032–1039.  Campistol JM, Arias M, Ariceta G, et al. Actualizacion en sindrome hemolitico uremico atipico: diagnostico y tratamiento. Documento de consenso. Nefrologia. 2015;35:421–447.