RESUMO
Atypical haemolytic uremic syndrome (aHUS) is a rare disorder characterised by complement-mediated thrombotic microangiopathy (TMA). Despite clinical guidelines, the diagnosis and treatment of aHUS in its early stages remains challenging. This study examined the annual trends in aHUS clinical practices in Japan and explored factors influencing early diagnosis and treatment. Using data from the 2011-2020 Diagnosis Procedure Combination database, 3096 cases with the HUS disease code were identified, of which 217 were confirmed as aHUS and treated with eculizumab or plasma exchange. Early initiation, defined as starting eculizumab or plasma exchange within 7 days of admission, was the focus of the study. Our study revealed no significant changes over time in the number of aHUS diagnoses, cases treated with eculizumab, or early initiation cases. Early initiation cases underwent haemodialysis earlier and had ADAMTS13 activity measured earlier, shorter hospital stays, and lower hospitalisation costs than late initiation cases. In conclusion, we found no increase in the number of newly diagnosed aHUS cases or early treatment initiation over time. Early recognition of TMA and differentiation of the causative disease are crucial for identifying potential aHUS cases, which may lead to better patient prognoses.
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Anticorpos Monoclonais Humanizados , Síndrome Hemolítico-Urêmica Atípica , Diagnóstico Precoce , Troca Plasmática , Humanos , Síndrome Hemolítico-Urêmica Atípica/diagnóstico , Síndrome Hemolítico-Urêmica Atípica/terapia , Síndrome Hemolítico-Urêmica Atípica/epidemiologia , Japão/epidemiologia , Feminino , Estudos Retrospectivos , Masculino , Adulto , Anticorpos Monoclonais Humanizados/uso terapêutico , Pessoa de Meia-Idade , Adolescente , Proteína ADAMTS13 , Adulto Jovem , Idoso , Criança , Pré-Escolar , Diálise RenalRESUMO
INTRODUCTION: Comprehensive information about atypical hemolytic uremic syndrome (aHUS) is relatively scarce outside of Europe and North America. This narrative review assembles available published data about the clinical presentation and management of aHUS in Latin America. AREAS COVERED: A search conducted in February 2023 of the MEDLINE (from inception), Embase (from inception), and LILACS/IBECS (1950 to 2023) databases using search terms 'atypical hemolytic uremic syndrome' and 'Latin America' and their variations retrieved 51 records (full papers and conference abstracts) published in English, Spanish, or Portuguese. After de-duplication, manual screening of titles/abstracts and addition of author-known articles, 25 articles were included of which 17 (68%) are full papers. All articles were published during the years 2013-2022. Articles include cohort studies, a registry analysis, and case reports from Argentina, Brazil, Chile and Columbia. Overall, Latin American patients with aHUS present the classic epidemiological, clinical, and genetic characteristics associated with this condition as described in other world regions. Depending on the country and time of reporting, aHUS in Latin America was treated mainly with plasma therapy and/or eculizumab. Where reported, eculizumab substantially improved aHUS-related outcomes in almost all adult and pediatric patients. EXPERT OPINION: Eculizumab has dramatically altered the natural course of aHUS, improving prognosis and patient outcomes. Addressing economic challenges and investing in healthcare infrastructure will be essential to implement strategies for timely detection and early treatment of aHUS in Latin America.
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Síndrome Hemolítico-Urêmica Atípica , Gerenciamento Clínico , Humanos , América Latina/epidemiologia , Síndrome Hemolítico-Urêmica Atípica/terapia , Síndrome Hemolítico-Urêmica Atípica/diagnóstico , Síndrome Hemolítico-Urêmica Atípica/epidemiologia , Anticorpos Monoclonais Humanizados/uso terapêuticoRESUMO
INTRODUCTION: Atypical haemolytic uremic syndrome (aHUS) is a rare form of thrombotic microangiopathy (TMA) associated with complement dysregulation; aHUS may be associated with other 'triggers' or 'clinical conditions'. This study aimed to characterize this patient population using data from the Global aHUS Registry, the largest collection of real-world data on patients with aHUS. METHODS: Patients enrolled in the Global aHUS Registry between April 2012 and June 2021 and with recorded aHUS-associated triggers or clinical conditions prior/up to aHUS onset were analysed. aHUS was diagnosed by the treating physician. Data were classified by age at onset of aHUS (< or ≥18 years) and additionally by the presence/absence of identified pathogenic complement genetic variant(s) and/or anti-complement factor H (CFH) antibodies. Genetically/immunologically untested patients were excluded. RESULTS: 1947 patients were enrolled in the Global aHUS Registry by June 2021, and 349 (17.9%) met inclusion criteria. 307/349 patients (88.0%) had a single associated trigger or clinical condition and were included in the primary analysis. Malignancy was most common (58/307, 18.9%), followed by pregnancy and acute infections (both 53/307, 17.3%). Patients with an associated trigger or clinical condition were generally more likely to be adults at aHUS onset. CONCLUSION: Our analysis suggests that aHUS-associated triggers or clinical conditions may be organized into clinically relevant categories, and their presence does not exclude the concurrent presence of pathogenic complement genetic variants and/or anti-CFH antibodies. Considering a diagnosis of aHUS with associated triggers or clinical conditions in patients presenting with TMA may allow faster and more appropriate treatment.
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Síndrome Hemolítico-Urêmica Atípica , Sistema de Registros , Humanos , Síndrome Hemolítico-Urêmica Atípica/genética , Síndrome Hemolítico-Urêmica Atípica/epidemiologia , Síndrome Hemolítico-Urêmica Atípica/diagnóstico , Síndrome Hemolítico-Urêmica Atípica/imunologia , Feminino , Masculino , Adulto , Pessoa de Meia-Idade , Adulto Jovem , Adolescente , Gravidez , Fator H do Complemento/genética , Fator H do Complemento/imunologia , Criança , Neoplasias/epidemiologia , Idade de Início , Pré-Escolar , Fatores de Risco , IdosoRESUMO
Thrombotic microangiopathies (TMA) are usually associated with hematological features (RH-TMA). The epidemiology of TMA limited to kidneys (RL-TMA) is unclear Therefore, patients with TMA and native kidney biopsies were identified during 2009-2022 in 20 French hospitals and results evaluated. RL-TMA was present in 341/757 (45%) patients and associated with lower creatinine levels (median 184 vs 346 µmol/L) than RH-TMA. RL-TMA resulted from virtually all identified causes, more frequently from anti-VEGF treatment and hematological malignancies but less frequently from shigatoxin-associated hemolytic uremic syndrome (HUS), systemic sclerosis, gemcitabine and bacterial infection, and even less frequently when three or more causes/triggers were combined (RL-TMA: 5%; RH-TMA: 12%). RL-TMA was associated with significantly lower major cardiovascular events (10% vs 20%), kidney replacement therapy (23% vs 43%) and death (12% vs 20%) than RH-TMA during follow-up (median 28 months). Atypical HUS (aHUS) was found in 326 patients (RL-TMA: 43%, RH-TMA: 44%). Among the 69 patients with proven complement-mediated aHUS, eculizumab (anti-C5 therapy) was used in 43 (62%) (RL-TMA: 35%; RH-TMA: 71%). Among the 257 other patients with aHUS, including 51% with RL-TMA, eculizumab was used in 29 but with unclear effects of this treatment. Thus, RL-TMA represents a very high proportion of patients with TMA and results from virtually all known causes of TMA and includes 25% of patients with complement-mediated aHUS. Adverse outcomes of RL-TMA are lower compared to RH-TMA but remain significant. Anti-C5 therapy was rarely used in RL-TMA, even in proven complement-mediated aHUS, and its effects remain to be assessed.
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Síndrome Hemolítico-Urêmica Atípica , Microangiopatias Trombóticas , Adulto , Humanos , Rim/patologia , Microangiopatias Trombóticas/epidemiologia , Microangiopatias Trombóticas/terapia , Microangiopatias Trombóticas/patologia , Síndrome Hemolítico-Urêmica Atípica/tratamento farmacológico , Síndrome Hemolítico-Urêmica Atípica/epidemiologia , Proteínas do Sistema Complemento , Testes de Função RenalRESUMO
RATIONALE & OBJECTIVE: Hemolytic uremic syndrome (HUS), a thrombotic microangiopathy (TMA) with kidney involvement, is a rare condition in patients with monoclonal gammopathy. In the absence of known causes of TMA, the role of complement activation in endothelial injury in patients with monoclonal gammopathy remains unknown and was the focus of this investigation. STUDY DESIGN: Case series. SETTING & PARTICIPANTS: We studied the 24 patients in the French national registry of HUS between 2000 and 2020 who had monoclonal gammopathy without other causes of secondary TMA. We provide the clinical histories and complement studies of these patients. FINDINGS: Monoclonal gammopathy-associated TMA with kidney involvement is estimated to be 10 times less frequent than adult atypical HUS (aHUS) in the French national registry. It is characterized by severe clinical features, with 17 of 24 patients requiring dialysis at disease onset, and with median renal survival of only 20 months. TMA-mediated extrarenal manifestations, particularly cutaneous and neurological involvement, were common and associated with poor overall prognosis. Complement studies identified low C3, normal C4, and high soluble C5b-9 levels in 33%, 100%, and 77% of tested patients, respectively, indicating a contribution of the alternative and terminal complement pathways in the pathophysiology of the disease. Genetic abnormalities in complement genes known to be associated with aHUS were found in only 3 of 17 (17%) who were tested. LIMITATIONS: Retrospective study without comparison group; limited number of patients, limited available blood samples. CONCLUSIONS: Within the spectrum of TMA, TMA associated with monoclonal gammopathy represents a distinct subset. Our findings suggest that HUS associated with monoclonal immunoglobulin is a complement-mediated disease akin to aHUS.
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Síndrome Hemolítico-Urêmica Atípica , Paraproteinemias , Microangiopatias Trombóticas , Adulto , Anticorpos Monoclonais Humanizados , Síndrome Hemolítico-Urêmica Atípica/epidemiologia , Síndrome Hemolítico-Urêmica Atípica/genética , Ativação do Complemento , Proteínas do Sistema Complemento , Humanos , Paraproteinemias/complicações , Paraproteinemias/epidemiologia , Estudos Retrospectivos , Microangiopatias Trombóticas/epidemiologia , Microangiopatias Trombóticas/etiologiaRESUMO
INTRODUCTION: Atypical hemolytic uremic syndrome (aHUS) is a rare and genetically mediated systemic disease most often caused by uncontrolled and chronic complement activation that leads to systemic thrombotic microangiopathy, renal and extra-renal damage. MATERIALS AND METHODS: This is descriptive, retrospective and multicenter study, which reports demographic, clinical, laboratory, and genetic characteristics, as well as their treatment response and outcome of 20 aHUS patients diagnosed between 2014 and 2018. RESULTS: Most patients were female adults (75%) and 30% were associated to pregnancy/postpartum, 15% to autoimmune disease, and 65% to infections. Gastrointestinal involvement (75%) was the most frequent extra-renal organ damage. Antenatal mortality and mortality rate were 5% and 10%, respectively. 25% of the patients progressed to end-stage renal disease. In 4/8 of patients treated within 1 week of presentation, eculizumab treatment restored multi-organ function after 4 weeks of treatment. CFH (37%) and CFI (25%) mutations were the most frequent. CONCLUSION: This is the first series of aHUS cases of Colombian Caribbean region which reports the clinical and epidemiological characteristics of this condition in this region.
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Síndrome Hemolítico-Urêmica Atípica , Microangiopatias Trombóticas , Adulto , Síndrome Hemolítico-Urêmica Atípica/epidemiologia , Síndrome Hemolítico-Urêmica Atípica/genética , Síndrome Hemolítico-Urêmica Atípica/terapia , Colômbia/epidemiologia , Ativação do Complemento , Feminino , Humanos , Masculino , Gravidez , Estudos Retrospectivos , Microangiopatias Trombóticas/complicações , Microangiopatias Trombóticas/diagnóstico , Microangiopatias Trombóticas/tratamento farmacológicoRESUMO
Introduction: Atypical hemolytic uremic syndrome (aHUS) is a rare disease that manifests with microangiopathic hemolytic anemia, thrombocytopenia, and acute renal failure, and is associated with dysregulation of the alternative complement pathway. The chromosomal region including CFH and CFHR1-5 is rich in repeated sequences, favoring genomic rearrangements that have been reported in several patients with aHUS. However, there are limited data on the prevalence of uncommon CFH-CFHR genomic rearrangements in aHUS and their impact on disease onset and outcomes. Methods: In this study, we report the results of CFH-CFHR Copy Number Variation (CNV) analysis and the characterization of resulting structural variants (SVs) in a large cohort of patients, including 258 patients with primary aHUS and 92 with secondary forms. Results: We found uncommon SVs in 8% of patients with primary aHUS: 70% carried rearrangements involving CFH alone or CFH and CFHR (group A; n=14), while 30% exhibited rearrangements including only CFHRs (group B; n=6). In group A, 6 patients presented CFH::CFHR1 hybrid genes, 7 patients carried duplications in the CFH-CFHR region that resulted either in the substitution of the last CFHR1 exon(s) with those of CFH (CFHR1::CFH reverse hybrid gene) or in an internal CFH duplication. In group A, the large majority of aHUS acute episodes not treated with eculizumab (12/13) resulted in chronic ESRD; in contrast, anti-complement therapy induced remission in 4/4 acute episodes. aHUS relapse occurred in 6/7 grafts without eculizumab prophylaxis and in 0/3 grafts with eculizumab prophylaxis. In group B, 5 subjects had the CFHR31-5::CFHR410 hybrid gene and one had 4 copies of CFHR1 and CFHR4. Compared with group A, patients in group B exhibited a higher prevalence of additional complement abnormalities and earlier disease onset. However, 4/6 patients in this group underwent complete remission without eculizumab treatment. In secondary forms we identified uncommon SVs in 2 out of 92 patients: the CFHR31-5::CFHR410 hybrid and a new internal duplication of CFH. Discussion: In conclusion, these data highlight that uncommon CFH-CFHR SVs are frequent in primary aHUS and quite rare in secondary forms. Notably, genomic rearrangements involving the CFH are associated with a poor prognosis but carriers respond to anti-complement therapy.
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Síndrome Hemolítico-Urêmica Atípica , Humanos , Síndrome Hemolítico-Urêmica Atípica/epidemiologia , Síndrome Hemolítico-Urêmica Atípica/genética , Síndrome Hemolítico-Urêmica Atípica/tratamento farmacológico , Fator H do Complemento/genética , Prevalência , Variações do Número de Cópias de DNA , Recidiva Local de Neoplasia , GenômicaAssuntos
Anticorpos Monoclonais Humanizados/uso terapêutico , Síndrome Hemolítico-Urêmica Atípica/tratamento farmacológico , COVID-19/epidemiologia , Pandemias , SARS-CoV-2 , Adulto , Síndrome Hemolítico-Urêmica Atípica/epidemiologia , Inativadores do Complemento/uso terapêutico , Feminino , Humanos , RecidivaRESUMO
BACKGROUND: Atypical hemolytic uremic syndrome (aHUS) is a rare disease in which uncontrolled terminal complement activation leads to systemic thrombotic microangiopathy (TMA). Pregnancy can trigger aHUS and, without complement inhibition, many women with pregnancy-triggered aHUS (p-aHUS) progress to end-stage renal disease (ESRD) with a high risk of morbidity. Owing to relatively small patient numbers, published characterizations of p-aHUS have been limited, thus the Global aHUS Registry (NCT01522183, April 2012) provides a unique opportunity to analyze data from a large single cohort of women with p-aHUS. METHODS: The demographics and clinical characteristics of women with p-aHUS (n = 51) were compared with those of women of childbearing age with aHUS and no identified trigger (non-p-aHUS, n = 397). Outcome evaluations, including renal survival according to time to ESRD, were compared for patients with and without eculizumab treatment (a complement C5 inhibitor) in both aHUS groups. RESULTS: Baseline demographics and clinical characteristics were broadly similar in both groups. The proportion of women with p-aHUS and non-p-aHUS with pathogenic variant(s) in complement genes and/or anti-complement factor H antibodies was similar (45% and 43%, respectively), as was the proportion with a family history of aHUS (12% and 13%, respectively). Eculizumab treatment led to significantly improved renal outcomes in women with aHUS, regardless of whether aHUS was triggered by pregnancy or not: adjusted hazard ratio for time to ESRD was 0.06 (p = 0.006) in the p-aHUS group and 0.20 (p < 0.0001) in the non-p-aHUS group. CONCLUSION: Findings from this study support the characterization of p-aHUS as a complement-mediated TMA.
Assuntos
Síndrome Hemolítico-Urêmica Atípica , Microangiopatias Trombóticas , Síndrome Hemolítico-Urêmica Atípica/diagnóstico , Síndrome Hemolítico-Urêmica Atípica/epidemiologia , Síndrome Hemolítico-Urêmica Atípica/genética , Inativadores do Complemento/uso terapêutico , Proteínas do Sistema Complemento , Feminino , Humanos , Gravidez , Sistema de Registros , Microangiopatias Trombóticas/diagnóstico , Microangiopatias Trombóticas/epidemiologiaRESUMO
AIMS: To describe the baseline characteristics and treatment of Australian patients diagnosed with atypical haemolytic uraemic syndrome (aHUS) reported to the Global aHUS Registry. METHODS: Descriptive analysis of the Australian cohort with aHUS (n = 106) was undertaken for demographics, disease characteristics and prior treatment with eculizumab; comparing with the global cohort (n = 1688) for certain pre-specified disease characteristics. RESULTS: In Australia, almost two-thirds of patients diagnosed with aHUS were female and over 80% of patients were Caucasians, with similar proportions reported in the global cohort. Less than 6% of patients in the Australia and global cohorts were reported to have a history of autoimmune disease (4% vs 2%, respectively; P = .21) or cancer (5% vs 5%, respectively; P = .93), conditions that have been associated with secondary HUS. In the Australian cohort, 26% had received a kidney transplant and 68% of patients had received eculizumab. Kidneys were the most common organ involvement, followed by gastrointestinal tract (26%) and cardiovascular system (19%), with 35% of patients reported to have had at least two organs involved within 6 months prior to baseline visit or entry into the registry. Complement factor H was the most common pathogenic complement gene variant in the Australian patients. CONCLUSION: Data from the aHUS registry confirms and defines region-specific disease characteristics among a selected group of Australian children and adults with aHUS reported to the registry. Ongoing and more inclusive data will provide further information about temporal trends and treatment outcomes, representing a unique opportunity for clinicians and researchers to further develop knowledge surrounding this rare disease.
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Anticorpos Monoclonais Humanizados/uso terapêutico , Síndrome Hemolítico-Urêmica Atípica , Rim/patologia , Adulto , Síndrome Hemolítico-Urêmica Atípica/epidemiologia , Síndrome Hemolítico-Urêmica Atípica/genética , Síndrome Hemolítico-Urêmica Atípica/fisiopatologia , Síndrome Hemolítico-Urêmica Atípica/terapia , Austrália/epidemiologia , Criança , Fator H do Complemento/genética , Inativadores do Complemento/uso terapêutico , Demografia , Feminino , Trato Gastrointestinal/patologia , Humanos , Transplante de Rim/estatística & dados numéricos , Masculino , Mutação , Sistema de Registros/estatística & dados numéricosRESUMO
Recessive mutations in diacylglycerol kinase epsilon (DGKE) display genetic pleiotropy, with pathological features reported as either thrombotic microangiopathy or membranoproliferative glomerulonephritis (MPGN), and clinical features of atypical hemolytic uremic syndrome (aHUS), nephrotic syndrome or both. Pathophysiological mechanisms and optimal management strategies have not yet been defined. In prospective and retrospective studies of aHUS referred to the United Kingdom National aHUS service and prospective studies of MPGN referred to the National Registry of Rare Kidney Diseases for MPGN we defined the incidence of DGKE aHUS as 0.009/million/year and so-called DGKE MPGN as 0.006/million/year, giving a combined incidence of 0.015/million/year. Here, we describe a cohort of sixteen individuals with DGKE nephropathy. One presented with isolated nephrotic syndrome. Analysis of pathological features reveals that DGKE mutations give an MPGN-like appearance to different extents, with but more often without changes in arterioles or arteries. In 15 patients presenting with aHUS, ten had concurrent substantial proteinuria. Identified triggering events were rare but coexistent developmental disorders were seen in six. Nine with aHUS experienced at least one relapse, although in only one did a relapse of aHUS occur after age five years. Persistent proteinuria was seen in the majority of cases. Only two individuals have reached end stage renal disease, 20 years after the initial presentation, and in one, renal transplantation was successfully undertaken without relapse. Six individuals received eculizumab. Relapses on treatment occurred in one individual. In four individuals eculizumab was withdrawn, with one spontaneously resolving aHUS relapse occurring. Thus we suggest that DGKE-mediated aHUS is eculizumab non-responsive and that in individuals who currently receive eculizumab therapy it can be safely withdrawn. This has important patient safety and economic implications.
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Síndrome Hemolítico-Urêmica Atípica , Diacilglicerol Quinase , Síndrome Hemolítico-Urêmica Atípica/tratamento farmacológico , Síndrome Hemolítico-Urêmica Atípica/epidemiologia , Síndrome Hemolítico-Urêmica Atípica/genética , Pré-Escolar , Diacilglicerol Quinase/genética , Humanos , Estudos Prospectivos , Estudos Retrospectivos , Reino UnidoRESUMO
Atypical haemolytic uraemic syndrome is an ultra-rare, life-threatening disease. Causative variants in genes that encode complement factors can be identified in 40-70% of cases. We performed genetic analysis of 21 Czech children with atypical haemolytic uraemic syndrome. Genetic or acquired predisposition to the disease was identified in the majority of our patients: CFHR1 and CFHR3 deletions in 14/21 (67%; 13 of them were positive for anti-complement factor H antibodies), variants in complement genes or DGKE in 13/21 (62%). Multiple genetic findings were identified in eight patients (38%). The incidence of atypical haemolytic uraemic syndrome in the Czech paediatric population was estimated to be 0.092 (CI 0.053-0.131) cases per million inhabitants and 0.92 (CI 0.53-1.32) cases per 100,000 births for the entire reporting period. Ten patients were initially treated with plasma exchange and eight with eculizumab or with a combination of eculizumab and plasma exchange. At the last follow-up, 20 patients were alive and one patient had end-stage renal disease.Conclusion: The incidence of atypical haemolytic uraemic syndrome in the Czech paediatric population corresponds to the reported incidence in Europe. We detected the unusually high rate of CFHR1/CFHR3 deletions associated with anti-complement factor H antibodies in Czech paediatric patients. Treatment by eculizumab led to superior outcomes and prevention of the disease relapses compared with plasma exchange therapy. Our results may help to understand the polygenic nature of atypical haemolytic uraemic syndrome as a disease that results from a combination of various risk factors. What is Known: ⢠Atypical haemolytic uraemic syndrome (aHUS) is considered a polygenic and multifactorial disease. Genetic predisposition to aHUS is identified in 40-70% of children. ⢠Anti-complement factor H antibodies are usually found in 6-25% of affected children. What is New: ⢠Potentially causative genetic or acquired factors were confirmed in the majority of patients. The prevailing finding was the unusually high rate of CFHR1/CFHR3 deletions associated with anti-complement factor H antibodies (62% of patients). ⢠The incidence of aHUS in Czech children is 0.092 (CI 0.053-0.131) cases per million inhabitants and 0.92 (CI 0.53-1.32) cases per 100,000 births for the entire reporting period.
Assuntos
Síndrome Hemolítico-Urêmica Atípica , Síndrome Hemolítico-Urêmica Atípica/epidemiologia , Síndrome Hemolítico-Urêmica Atípica/genética , Síndrome Hemolítico-Urêmica Atípica/terapia , Criança , República Tcheca/epidemiologia , Europa (Continente) , Humanos , Troca Plasmática , Fatores de RiscoRESUMO
Pregnancy has been linked to various microangiopathies, including primary atypical haemolytic uraemic syndrome (aHUS). Complement dysregulation, often linked to rare variants in complement genes, is key for primary aHUS to manifest and may play a role in pregnancy complications of the mother and fetus. The burden of such complications is unknown, making counselling of women with primary aHUS and asymptomatic relatives difficult. We analyzed the maternal and fetal outcomes of 39 pregnancies from 17 women with primary aHUS and two asymptomatic relatives. Seven out of 39 pregnancies were complicated by pregnancy-associated aHUS. Five out of 32 pregnancies not linked to pregnancy-associated aHUS were complicated by pre-eclampsia or HELLP. Rare genetic variants were identified in 10 women (asymptomatic relatives, n = 2) who had a total of 14 pregnancies, including 10 uncomplicated pregnancies. Thirty-five out of 39 pregnancies resulted in live birth. Eight out of 19 women had progressed to end-stage kidney disease, with an incidence of 2·95 (95% confidence interval, 1·37-5·61) per 100 person-years after the first pregnancy. Thus, we emphasized the frequency of successful pregnancies in women with primary aHUS and asymptomatic relatives. Pregnancies should be monitored closely. Rare genetic variants cannot predict the risk of a given pregnancy.
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Síndrome Hemolítico-Urêmica Atípica/epidemiologia , Polimorfismo de Nucleotídeo Único , Complicações na Gravidez/epidemiologia , Aborto Espontâneo/epidemiologia , Alelos , Doenças Assintomáticas , Síndrome Hemolítico-Urêmica Atípica/genética , Família , Feminino , Frequência do Gene , Idade Gestacional , Síndrome HELLP/epidemiologia , Humanos , Recém-Nascido , Nascido Vivo , Reação em Cadeia da Polimerase Multiplex , Pré-Eclâmpsia/epidemiologia , Gravidez , Complicações na Gravidez/genética , Resultado da GravidezRESUMO
Factor H (FH), a member of the regulators-of-complement-activation (RCA) family of proteins, circulates in human plasma at concentrations of 180-420 mg/L where it controls the alternative pathway (AP) of complement in the fluid phase and on cell surfaces. When the regulatory function of FH is impaired, complement-mediated tissue injury and inflammation occur, leading to diseases such as atypical hemolytic uremic syndrome (a thrombotic microangiopathy or TMA), C3 glomerulopathy (C3G) and monoclonal gammopathy of renal significance (MGRS). A pathophysiological cause of compromised FH function is the development of autoantibodies to various domains of the FH protein. FH autoantibodies (FHAAs) are identified in 10.9% of patients with aHUS, 3.2% of patients with C3G, and rarely in patients with MGRS. The phenotypic variability of FHAA-mediated disease reflects both the complexity of FH and the epitope specificity of FHAA for select regions of the native protein. In this paper, we have characterized FHAA epitopes in a large cohort of patients diagnosed with TMA, C3G or MGRS. We explore the epitopes recognized by FHAAs in these diseases and the association of FHAAs with the genetic deletion of both copies of the CFHR1 gene to show how these disease phenotypes are associated with this diverse spectrum of autoantibodies.
Assuntos
Síndrome Hemolítico-Urêmica Atípica/imunologia , Autoanticorpos/sangue , Glomerulonefrite/imunologia , Paraproteinemias/imunologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Síndrome Hemolítico-Urêmica Atípica/sangue , Síndrome Hemolítico-Urêmica Atípica/epidemiologia , Síndrome Hemolítico-Urêmica Atípica/genética , Biomarcadores/sangue , Criança , Pré-Escolar , Proteínas Inativadoras do Complemento C3b/genética , Fator H do Complemento/imunologia , Epitopos , Feminino , Deleção de Genes , Predisposição Genética para Doença , Glomerulonefrite/sangue , Glomerulonefrite/epidemiologia , Glomerulonefrite/genética , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Paraproteinemias/sangue , Paraproteinemias/epidemiologia , Paraproteinemias/genética , Fenótipo , Prevalência , Estudos Retrospectivos , Estados Unidos/epidemiologia , Adulto JovemRESUMO
AIM: Atypical hemolytic uremic syndrome (aHUS), characterized by thrombotic microangiopathy (TMA), is a genetic, life-threatening disease which needs many differential diagnoses. This study aimed to reveal coagulation and fibrinolysis profiles in aHUS and secondary TMA patients. Furthermore, we investigated whether aHUS patients progress to, and meet, disseminated intravascular coagulation (DIC) criteria. METHODS: The acute phase samples were available in 15 aHUS and 20 secondary TMA patients. We measured PT-ratio, activated partial thromboplastin time (APTT), fibrinogen, fibrin degradation product (FDP), fibrin monomer complex (FMC), antithrombin (AT), plasmin-α2 plasmin inhibitor complex (PIC), and von Willebrand factor antigen (VWF:Ag). We examined and compared these tests among aHUS, secondary TMA patients, and healthy volunteer (HV), and evaluated whether patients with aHUS and secondary TMA met DIC criteria. RESULTS: PT-ratio, APTT, FDP, FMC and PIC in patients with aHUS and secondary TMA were higher than those in HV. Fibrinogen and AT showed no significant difference among three groups. VWF:Ag was higher in only aHUS patients. No tests showed significant difference between aHUS and secondary TMA patients. Three aHUS patients out of 15 met DIC criteria. CONCLUSION: We revealed the profiles and distributions of coagulation and fibrinolysis tests of aHUS and secondary TMA patients. All tests were enhanced compared to HV; however, our results showed the no specificities in distinguishing aHUS from secondary TMA patients. We also clarified that some aHUS patients fulfilled DIC diagnostic criteria, indicating that DIC itself cannot be an exclusion criterion of aHUS.
Assuntos
Síndrome Hemolítico-Urêmica Atípica/diagnóstico , Biomarcadores/sangue , Coagulação Sanguínea , Fibrinólise , Microangiopatias Trombóticas/diagnóstico , Adolescente , Adulto , Idoso , Síndrome Hemolítico-Urêmica Atípica/sangue , Síndrome Hemolítico-Urêmica Atípica/epidemiologia , Testes de Coagulação Sanguínea , Criança , Pré-Escolar , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Microangiopatias Trombóticas/sangue , Microangiopatias Trombóticas/epidemiologia , Adulto JovemRESUMO
BACKGROUND: Atypical hemolytic uremic syndrome (HUS) is associated with high recurrence rates after kidney transplant, with devastating outcomes. In late 2011, experts in France recommended the use of highly individualized complement blockade-based prophylaxis with eculizumab to prevent post-transplant atypical HUS recurrence throughout the country. METHODS: To evaluate this strategy's effect on kidney transplant prognosis, we conducted a retrospective multicenter study from a large French nationwide registry, enrolling all adult patients with atypical HUS who had undergone complement analysis and a kidney transplant since January 1, 2007. To assess how atypical HUS epidemiology in France in the eculizumab era evolved, we undertook a population-based cohort study that included all adult patients with atypical HUS (n=397) between 2007 and 2016. RESULTS: The first study included 126 kidney transplants performed in 116 patients, 58.7% and 34.1% of which were considered to be at a high and moderate risk of atypical HUS recurrence, respectively. Eculizumab prophylaxis was used in 52 kidney transplants, including 39 at high risk of recurrence. Atypical HUS recurred after 43 (34.1%) of the transplants; in four cases, patients had received eculizumab prophylaxis and in 39 cases they did not. Use of prophylactic eculizumab was independently associated with a significantly reduced risk of recurrence and with significantly longer graft survival. In the second, population-based cohort study, the proportion of transplant recipients among patients with ESKD and atypical HUS sharply increased between 2012 and 2016, from 46.2% to 72.3%, and showed a close correlation with increasing eculizumab use among the transplant recipients. CONCLUSIONS: Results from this observational study are consistent with benefit from eculizumab prophylaxis based on pretransplant risk stratification and support the need for a rigorous randomized trial.
Assuntos
Anticorpos Monoclonais Humanizados/uso terapêutico , Síndrome Hemolítico-Urêmica Atípica/tratamento farmacológico , Inativadores do Complemento/uso terapêutico , Transplante de Rim , Adulto , Síndrome Hemolítico-Urêmica Atípica/epidemiologia , Síndrome Hemolítico-Urêmica Atípica/genética , Síndrome Hemolítico-Urêmica Atípica/cirurgia , Proteínas Inativadoras do Complemento C3b/genética , Proteínas do Sistema Complemento/análise , Feminino , França , Sobrevivência de Enxerto/efeitos dos fármacos , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Proteínas Mutantes Quiméricas/genética , Cuidados Pré-Operatórios , Modelos de Riscos Proporcionais , Recidiva , Sistema de Registros , Estudos Retrospectivos , Prevenção SecundáriaRESUMO
BACKGROUND: There are limited long-term outcome data in eculizumab-treated patients with atypical hemolytic uremic syndrome (aHUS). We report final results from the largest prospective, observational, multicenter study of patients with aHUS treated with eculizumab. METHODS: Patients with aHUS who participated in any of five parent eculizumab trials and received at least one eculizumab infusion were eligible for enrollment in a long-term follow-up study. Rates of thrombotic microangiopathy (TMA) manifestations off versus on eculizumab were evaluated. Additional endpoints included change from baseline estimated glomerular filtration rate (eGFR), long-term renal outcomes, and serious targeted treatment-emergent adverse events. RESULTS: Among 93 patients (0-80 years of age), 51 (55%) remained on eculizumab and 42 (45%) discontinued; for those who discontinued, 21 (50%) reinitiated therapy. Patients who reinitiated eculizumab had similar baseline clinical characteristics to patients who remained on eculizumab, with higher likelihood of genetic/autoimmune complement abnormalities, more prior TMAs, and longer disease course versus those who did not reinitiate. Mean eGFR improved rapidly and remained stable for up to 6 years on eculizumab. In patients who discontinued, there was a trend toward decreasing renal function over time from discontinuation. Additionally, off-treatment TMA manifestation rates were higher in those aged < 18 years at diagnosis, with identified genetic/autoimmune complement abnormalities, or history of multiple TMAs prior to eculizumab initiation. The safety profile was consistent with previous studies. Three definite and one possible meningococcal infections related to eculizumab were reported and resolved with treatment. Three deaths unrelated to eculizumab were reported. CONCLUSIONS: The current study confirms the efficacy and safety of eculizumab in aHUS, particularly with regard to long-term renal function and TMA events. Pediatric age at disease onset and presence of genetic or autoimmune complement abnormalities are risk factors for TMA events off treatment. Overall, patients who discontinue eculizumab may be at risk for additional TMA manifestations and renal function decreases. Discontinuation of eculizumab, with careful monitoring, is an option in select patients with consideration of patient preference, organ function normalization, and risk factors for relapse, including mutational analysis, age of onset, and history of multiple TMA episodes. TRIAL REGISTRATION: ClinicalTrials.gov NCT01522170 , January 31, 2012.
Assuntos
Anticorpos Monoclonais Humanizados , Síndrome Hemolítico-Urêmica Atípica/tratamento farmacológico , Efeitos Adversos de Longa Duração , Microangiopatias Trombóticas , Adolescente , Adulto , Anticorpos Monoclonais Humanizados/administração & dosagem , Anticorpos Monoclonais Humanizados/efeitos adversos , Síndrome Hemolítico-Urêmica Atípica/complicações , Síndrome Hemolítico-Urêmica Atípica/diagnóstico , Síndrome Hemolítico-Urêmica Atípica/epidemiologia , Criança , Inativadores do Complemento/administração & dosagem , Inativadores do Complemento/efeitos adversos , Feminino , Seguimentos , Taxa de Filtração Glomerular , Humanos , Cooperação Internacional , Efeitos Adversos de Longa Duração/diagnóstico , Efeitos Adversos de Longa Duração/epidemiologia , Efeitos Adversos de Longa Duração/etiologia , Masculino , Conduta do Tratamento Medicamentoso , Avaliação de Processos e Resultados em Cuidados de Saúde , Microangiopatias Trombóticas/diagnóstico , Microangiopatias Trombóticas/epidemiologia , Microangiopatias Trombóticas/etiologiaRESUMO
AIM: The aim of the present study was to characterize the molecular basis of complement factor I deficiency in Tunisian atypical haemolytic and uremic syndrome patients with low factor I levels. METHODS: Six adults and seven children were enrolled in this study. Complement factor I levels were assessed by a homemade sandwich ELISA and ranged between 12.5% and 60%. Genomic DNA was amplified by way of a polymerase chain reaction using intronic primers flanking the 13 coding exons. Sequencing of amplified products was carried out by the dye terminator sequencing method. Molecular study was performed on parental samples for three dead paediatric patients. The control group consisted of 100 healthy Tunisian donors. RESULTS: We identified a total of 13 substitutions and one insertion: seven in introns, four in exons and three in UTR. The new mutations were c.-132G > C, c.71 + 181 T > A in 5'UTR and intron 1, respectively. Three intronic polymorphisms were predicted to have impact on splicing events: c.482 + 6C > T, c.884-42_884-41insTTAAA (rs34422850) and c.1429 + 33 A > G (rs9998151). They were three missense mutations leading to a p.Ile 357Met, p.Ile416Leu and p.GLu548Gln. p.Ile 357Met was found in two patients and one relative. Half of the patients had associated mutation and/or polymorphisms. CONCLUSION: This is the first genetic study in Tunisian and Maghrebin atypical haemolytic and uraemic syndrome patients. The high occurrence of Ile357Met mutation may reflect a founding effect. Functional impact of the two new mutations c.-132G > C and c.71 + 181A > T have to be studied. Association of simultaneous genetic abnormalities may explain the variability of atypical haemolytic and uraemic syndrome, penetrance and disease phenotype.
Assuntos
Síndrome Hemolítico-Urêmica Atípica , Complemento C3/deficiência , Fator I do Complemento , Doenças Genéticas Inatas , Adulto , Síndrome Hemolítico-Urêmica Atípica/diagnóstico , Síndrome Hemolítico-Urêmica Atípica/epidemiologia , Síndrome Hemolítico-Urêmica Atípica/genética , Criança , Pré-Escolar , Estudos de Coortes , Complemento C3/genética , Fator I do Complemento/análise , Fator I do Complemento/genética , Feminino , Doenças Genéticas Inatas/sangue , Doenças Genéticas Inatas/epidemiologia , Doenças Genéticas Inatas/genética , Doenças da Deficiência Hereditária de Complemento , Humanos , Lactente , Masculino , Mutação , Polimorfismo Genético , Tunísia/epidemiologiaRESUMO
BACKGROUND Atypical hemolytic uremic syndrome (aHUS), a rare thrombotic microangiopathy, is characterized by hemolytic anemia, thrombocytopenia, and acute renal failure. Caused by genetic mutations in the alternative complement cascade, aHUS often will culminate in end-stage renal disease and occasionally death. Renal transplantation in aHUS patients has been contraindicated in the past due to the recurrence risk, with certain immunosuppressive regimens being commonly attributed. In this study, we analyzed the association between aHUS and immunosuppressive agents so as to offer evidence for the use of certain immunosuppressive regimens in renal transplant recipients. MATERIAL AND METHODS Our study is a retrospective analysis using data from the United States Renal Data System from 2004 to 2012. A cohort of renal transplantation patients diagnosed with aHUS were identified to include in the study. The primary endpoint was the determination of aHUS incidence in renal transplant recipients due to various immunosuppressive agents. The secondary endpoints were to check the relationship between the drug type as well as the demographic variables that increase the risk for aHUS. RESULTS It was found that there was a higher usage of sirolimus (P=0.015) and corticosteroids (P=0.030) in the aHUS patients compared to patients in other diagnoses group. CONCLUSIONS There was a higher usage of sirolimus and corticosteroids in renal transplantation patients diagnosed with aHUS. Unfortunately, due to the rarity of this disease, the sample size was small (n=14). Despite the small sample size, this data analysis throws light on the relationship between aHUS and immunosuppressive agents in renal transplant recipients, although we still have much to learn.
Assuntos
Síndrome Hemolítico-Urêmica Atípica/epidemiologia , Imunossupressores/efeitos adversos , Falência Renal Crônica/cirurgia , Transplante de Rim/efeitos adversos , Complicações Pós-Operatórias/epidemiologia , Corticosteroides/efeitos adversos , Adulto , Síndrome Hemolítico-Urêmica Atípica/etiologia , Feminino , Humanos , Terapia de Imunossupressão/efeitos adversos , Incidência , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/etiologia , Estudos Retrospectivos , Sirolimo/efeitos adversos , TransplantadosRESUMO
The gain-of-function variation p.I1157T in C3 was previously identified in 8 patients with atypical hemolytic uremic syndrome (aHUS) at Mie University Hospital. In the present study, we identified another 11 patients with aHUS with this variation, including 10 pediatric patients (onset age: 1-16 years). The variation seems to be geographically concentrated around Mie Prefecture in Japan. Fifteen of the 19 patients with aHUS experienced infection as probable triggering events. All 19 patients had renal dysfunction. Seven patients, including 2 from the previous study and 5 from the present study, were treated with eculizumab, with all showing a good response with hematological normalization. Among the 5 eculizumab-treated patients in the present study, 3 had an ambiguous diagnosis of aHUS due to low-grade hemolysis even with elevated levels of lactate dehydrogenase and bilirubin. In those cases, in-house targeted DNA sequencing identified the C3 p.I1157T variation carriers, which enabled the early initiation of treatment with eculizumab. The present study supports the early introduction of eculizumab in patients with aHUS, especially pediatric patients.