A comprehensive model for assessing and classifying patients with thrombotic microangiopathy: the TMA-INSIGHT score.

BACKGROUND: Thrombotic Microangiopathy (TMA) is a syndrome characterized by the presence of anemia, thrombocytopenia and organ damage and has multiple etiologies. The primary aim is to develop an algorithm to classify TMA (TMA-INSIGHT score). METHODS: This was a single-center retrospective cohort study including hospitalized patients with TMA at a single center. We included all consecutive patients diagnosed with TMA between 2012 and 2021. TMA was defined based on the presence of anemia (hemoglobin level < 10 g/dL) and thrombocytopenia (platelet count < 150,000/µL), signs of hemolysis, and organ damage. We classified patients in eight categories: infections; Malignant Hypertension; Transplant; Malignancy; Pregnancy; Thrombotic Thrombocytopenic Purpura (TTP); Shiga toxin-mediated hemolytic uremic syndrome (STEC-SHU) and Complement Mediated TMA (aHUS). We fitted a model to classify patients using clinical characteristics, biochemical exams, and mean arterial pressure at presentation. RESULTS: We retrospectively retrieved TMA phenotypes using automatic strategies in electronic health records in almost 10 years (n = 2407). Secondary TMA was found in 97.5% of the patients. Primary TMA was found in 2.47% of the patients (TTP and aHUS). The best model was LightGBM with accuracy of 0.979, and multiclass ROC-AUC of 0.966. The predictions had higher accuracy in most TMA classes, although the confidence was lower in aHUS and STEC-HUS cases. CONCLUSION: Secondary conditions were the most common etiologies of TMA. We retrieved comorbidities, associated conditions, and mean arterial pressure to fit a model to predict TMA and define TMA phenotypic characteristics. This is the first multiclass model to predict TMA including primary and secondary conditions.

The challenges of the pandemic and the vaccination against covid-19 in pediatric patients with kidney disease / Os desafios da pandemia e a vacinação covid-19 na população pediátrica com doenças renais

ABSTRACT The covid-19 vaccine confers direct protection and reduces transmission rates of the virus and new variants. Vaccines from Pfizer/BioNTech and CoronaVac have been cleared for children in Brazil. They are safe, effective, and immunogenic. There are no known complications associated with the use of steroids or vaccines in pediatric patients with covid-19 and nephrotic syndrome. With or without immunosuppression, these patients are not at increased risk of severe covid-19, and steroids are safe for them. A milder form of covid-19 occurs in patients with chronic kidney disease without the need for hospitalization. The vaccine response may be reduced and/or the duration of antibodies after vaccination may be shorter than in the general population. However, considering risk of exposure, vaccination against covid-19 is recommended. It is believed that patients with hemolytic-uremic syndrome are at higher risk of severe covid-19. Vaccination is recommended, although specific data on the safety and efficacy of the covid-19 vaccine are limited. There is agreement that the benefits of induced immunity outweigh the risks of immunization. Vaccination against covid-19 is recommended for children and adolescents needing kidney transplantation or who have undergone transplantation. These patients present decreased immune response after vaccination, but immunization is recommended because the benefits outweigh the risks of vaccination. Current recommendations in Brazil stipulate the use of the messenger RNA vaccine. This paper aims to provide pediatric nephrologists with the latest knowledge about vaccination against covid-19 for children with kidney disease.

Resumo A vacina covid-19 confere proteção direta, reduz as taxas de transmissão do vírus e de novas variantes. No Brasil, estão liberadas para a população pediátrica as vacinas Pfizer/BioNTech e a CoronaVac, ambas seguras, eficazes e imunogênicas. Pacientes pediátricos com síndrome nefrótica e covid-19 têm curso clínico regular sem complicações relacionadas ao uso de esteroides ou vacinas. Esses pacientes, com ou sem imunossupressão, não apresentam maior risco de covid-19 grave e o tratamento com esteroides é seguro. Os pacientes com doença renal crônica têm covid-19 mais leve, sem necessidade de hospitalização. A resposta vacinal pode ser reduzida e/ou a duração dos anticorpos pós-vacinação pode ser menor do que na população geral. Entretanto, a vacina covid-19 está recomendada, considerando o risco de exposição. Acredita-se que pacientes com síndrome hemolítico-urêmica teriam maior risco de covid-19 grave. A vacina é recomendada, embora dados específicos sobre segurança e eficácia da vacina covid-19 sejam limitados. Há concordância que os benefícios da imunidade induzida superam quaisquer riscos da imunização. A vacina covid-19 é recomendada para crianças e adolescentes candidatos ao transplante renal ou já transplantados. Esses pacientes têm resposta imunológica reduzida após a vacina, entretanto ela é recomendada porque os benefícios superam qualquer risco dessa vacinação. A recomendação atual no Brasil é a vacina de tecnologia RNA mensageiro. O objetivo deste documento é levar aos nefrologistas pediátricos os conhecimentos mais recentes sobre a vacinação contra contra-19 em crianças com doenças renais.

The challenges of the pandemic and the vaccination against covid-19 in pediatric patients with kidney disease.

The covid-19 vaccine confers direct protection and reduces transmission rates of the virus and new variants. Vaccines from Pfizer/BioNTech and CoronaVac have been cleared for children in Brazil. They are safe, effective, and immunogenic. There are no known complications associated with the use of steroids or vaccines in pediatric patients with covid-19 and nephrotic syndrome. With or without immunosuppression, these patients are not at increased risk of severe covid-19, and steroids are safe for them. A milder form of covid-19 occurs in patients with chronic kidney disease without the need for hospitalization. The vaccine response may be reduced and/or the duration of antibodies after vaccination may be shorter than in the general population. However, considering risk of exposure, vaccination against covid-19 is recommended. It is believed that patients with hemolytic-uremic syndrome are at higher risk of severe covid-19. Vaccination is recommended, although specific data on the safety and efficacy of the covid-19 vaccine are limited. There is agreement that the benefits of induced immunity outweigh the risks of immunization. Vaccination against covid-19 is recommended for children and adolescents needing kidney transplantation or who have undergone transplantation. These patients present decreased immune response after vaccination, but immunization is recommended because the benefits outweigh the risks of vaccination. Current recommendations in Brazil stipulate the use of the messenger RNA vaccine. This paper aims to provide pediatric nephrologists with the latest knowledge about vaccination against covid-19 for children with kidney disease.

Pediatric peritoneal dialysis in Brazil: a discussion about sustainability. A document by the Brazilian Society of Nephrology, the Brazilian Society of Pediatrics, the Brazilian Association of Organ Transplantation, and the Brazilian Association of Dialysis and Transplant Centers / Diálise peritoneal pediátrica no Brasil: momento de discutir a sustentabilidade. Um documento da Sociedade Brasileira de Nefrologia, Sociedade Brasileira de Pediatria, Associação Brasileira de Transplante de Órgãos e Associação Brasileira de Centros de Diálise e Transplante

Abstract Introdução: A diálise peritoneal (DP) é importante para a pediatria. Este estudo mostrou dados de centros brasileiros que utilizam DP pediátrica. Método: Estudo transversal, observacional, descritivo com questionário eletrônico. Incluiu-se pacientes de 0-18 anos em DP cadastrados nos bancos de dados dos diversos centros. Questionário preenchido anonimamente, sem dados de identificação. Foi adotada metodologia quantitativa. Resultados: 212 pacientes estão em DP no Brasil (agosto, 2021). 80% têm menos de 12 anos de idade. A maioria realiza DP automatizada e 74% são dependentes do Sistema Único de Saúde. Em 25% dos centros faltou material de DP e em 51% os pacientes pediátricos foram convertidos de DP para HD. Conclusão: A maioria dos pacientes tinha menos de 12 anos e era dependente do SUS. A escassez de insumos aconteceu em 25% dos centros. Esses dados apontam para o problema da sustentabilidade de DP, única alternativa de TRS em crianças muito pequenas.

Resumo Introdução: A diálise peritoneal (DP) é importante para a pediatria. Este estudo mostrou dados de centros brasileiros que utilizam DP pediátrica. Método: Estudo transversal, observacional, descritivo com questionário eletrônico. Incluiu-se pacientes de 0-18 anos em DP cadastrados nos bancos de dados dos diversos centros. Questionário preenchido anonimamente, sem dados de identificação. Foi adotada metodologia quantitativa. Resultados: 212 pacientes estão em DP no Brasil (agosto, 2021). 80% têm menos de 12 anos de idade. A maioria realiza DP automatizada e 74% são dependentes do Sistema Único de Saúde. Em 25% dos centros faltou material de DP e em 51% os pacientes pediátricos foram convertidos de DP para HD. Conclusão: A maioria dos pacientes tinha menos de 12 anos e era dependente do SUS. A escassez de insumos aconteceu em 25% dos centros. Esses dados apontam para o problema da sustentabilidade de DP, única alternativa de TRS em crianças muito pequenas.

Baseline characteristics and evolution of Brazilian patients with atypical hemolytic uremic syndrome: first report of the Brazilian aHUS Registry.

Background: Atypical hemolytic uremic syndrome (aHUS) is an ultra-rare disease. Therefore, studies involving large samples are scarce, making registries powerful tools to evaluate cases. We present herein the first analysis of the Brazilian aHUS Registry (BRaHUS). Methods: Analysis of clinical, laboratory, genetic and treatment data from patients inserted in the BRaHUS, from 2017 to 2020, as an initiative of the Rare Diseases Committee of the Brazilian Society of Nephrology. Results: The cohort consisted of 75 patients (40 adults and 35 pediatric). There was a predominance of women (56%), median age at diagnosis of 20.7 years and a positive family history in 8% of cases. Renal involvement was observed in all cases and 37% had low C3 levels. In the <2 years of age group, males were predominant. Children presented lower levels of hemoglobin (P = .01) and platelets (P = .003), and higher levels of lactate dehydrogenase (LDH) (P = .004) than adults. Genetic analysis performed in 44% of patients revealed pathogenic variants in 66.6% of them, mainly in CFH and the CFHR1-3 deletion. Plasmapheresis was performed more often in adults (P = .005) and 97.3% of patients were treated with eculizumab and its earlier administration was associated with dialysis-free after 3 months (P = .08). Conclusions: The cohort of BRaHUS was predominantly composed of female young adults, with renal involvement in all cases. Pediatric patients had lower hemoglobin and platelet levels and higher LDH levels than adults, and the most common genetic variants were identified in CFH and the CFHR1-3 deletion with no preference of age, a peculiar pattern of Brazilian patients.

Eculizumab in low-middle income countries: how much does a life cost?

Atypical hemolytic uremic syndrome (aHUS) is an ultra-rare disease and eculizumab was approved as first line therapy in 2011 by the Food and Drug Administration. Access to eculizumab in low-middle income countries is challenging. We discuss access to eculizumab in Brazil that was made possible by judicialization or compassionate use. We showed a nationwide cohort of unplanned eculizumab interruptions resulted in higher rates of aHUS relapse. Similar to the French cohort, the use of eculizumab after transplantation showed superior graft survival compared to conventional treatment. We speculate a possible solution to the higher cost of eculizumab in which the government negotiates with the manufacturers. In this process, the government should compromise to ensure validated protocols of drug use, and the pharmaceutical companies, on the other hand, should reduce prices, especially in low-income countries. We also suggest a price adjustment based on gross domestic product.

Pediatric peritoneal dialysis in Brazil: a discussion about sustainability. A document by the Brazilian Society of Nephrology, the Brazilian Society of Pediatrics, the Brazilian Association of Organ Transplantation, and the Brazilian Association of Dialysis and Transplant Centers.

INTRODUçÃO: A diálise peritoneal (DP) é importante para a pediatria. Este estudo mostrou dados de centros brasileiros que utilizam DP pediátrica. MÉTODO: Estudo transversal, observacional, descritivo com questionário eletrônico. Incluiu-se pacientes de 0-18 anos em DP cadastrados nos bancos de dados dos diversos centros. Questionário preenchido anonimamente, sem dados de identificação. Foi adotada metodologia quantitativa. RESULTADOS: 212 pacientes estão em DP no Brasil (agosto, 2021). 80% têm menos de 12 anos de idade. A maioria realiza DP automatizada e 74% são dependentes do Sistema Único de Saúde. Em 25% dos centros faltou material de DP e em 51% os pacientes pediátricos foram convertidos de DP para HD. CONCLUSÃO: A maioria dos pacientes tinha menos de 12 anos e era dependente do SUS. A escassez de insumos aconteceu em 25% dos centros. Esses dados apontam para o problema da sustentabilidade de DP, única alternativa de TRS em crianças muito pequenas.

Thrombotic microangiopathy after kidney transplantation: Analysis of the Brazilian Atypical Hemolytic Uremic Syndrome cohort.

BACKGROUND: Atypical Hemolytic Uremic Syndrome (aHUS) is an ultra-rare disease that potentially leads to kidney graft failure due to ongoing Thrombotic Microangiopathy (TMA). The aim was evaluating the frequency of TMA after kidney transplantation in patients with aHUS in a Brazilian cohort stratified by the use of the specific complement-inhibitor eculizumab. METHODS: This was a multicenter retrospective cohort study including kidney transplant patients diagnosed with aHUS. We collected data from 118 transplant centers in Brazil concerning aHUS transplanted patients between 01/01/2007 and 12/31/2019. Patients were stratified into three groups: no use of eculizumab (No Eculizumab Group), use of eculizumab for treatment of after transplantation TMA (Therapeutic Group), and use of eculizumab for prophylaxis of aHUS recurrence (Prophylactic Group). RESULTS: Thirty-eight patients with aHUS who received kidney transplantation were enrolled in the study. Patients' mean age was 30 years (24-40), and the majority of participants was women (63% of cases). In the No Eculizumab Group (n = 11), there was a 91% graft loss due to the TMA. The hazard ratio of TMA graft loss was 0.07 [0.01-0.55], p = 0.012 in the eculizumab Prophylactic Group and 0.04 [0.00-0.28], p = 0.002 in the eculizumab Therapeutic Group. CONCLUSION: The TMA graft loss in the absence of a specific complement-inhibitor was higher among the Brazilian cohort of kidney transplant patients. This finding reinforces the need of eculizumab use for treatment of aHUS kidney transplant patients. Cost optimization analysis and the early access to C5 inhibitors are suggested, especially in low-medium income countries.

Atypical hemolytic uremic syndrome in Brazil: clinical presentation, genetic findings and outcomes of a case series in adults and children treated with eculizumab.

BACKGROUND: Atypical hemolytic uremic syndrome (aHUS) is characterized by microangiopathic hemolytic anemia, thrombocytopenia and kidney injury caused by a dysregulation of the alternative complement pathway. METHODS: We conducted a multicenter nonregistry study aimed at collecting clinical, laboratory and genetic information of patients with aHUS in Brazil. Demographic data, genetic findings, treatments and outcomes are presented. RESULTS: Thirty-four patients were included, 62% were female and 67% were Caucasian. Half of the patients had the first manifestation of aHUS before the age of 18 years (pediatric group). Among the 17 patients who had the first manifestation after the age of 18 years (adult group), 6 were kidney transplant patients. Overall, 22 patients (65%) received plasma exchange/plasma infusion (PE/PI) and 31 patients (91%) received eculizumab. Eculizumab was started later in the adult group compared with the pediatric group. Two patients stopped dialysis after PE/PI and 19 patients stopped dialysis after eculizumab despite a late start. A pathogenic/likely pathogenic variant was found in 24.3% of patients. A coexisting condition or trigger was present in 59% of patients (infections, pregnancy, hypertension, autoimmune disease and transplant), especially in the adult group. There was a 30% relapse rate after stopping eculizumab, irrespective of genetic status. CONCLUSION: This is the largest case series of aHUS in Brazil involving a wide range of patients for which eculizumab was the main treatment. Although eculizumab was started later than advised in the guidelines, most patients were able to stop dialysis at variable intervals. Discontinuation of eculizumab was associated with a 30% relapse of aHUS.

APOL1 in an ethnically diverse pediatric population with nephrotic syndrome: implications in focal segmental glomerulosclerosis and other diagnoses.

BACKGROUND: APOL1 high-risk genotypes (HRG) are associated with increased risk of kidney disease in individuals of African ancestry. We analyzed the effects of APOL1 risk variants on an ethnically diverse Brazilian pediatric nephrotic syndrome (NS) cohort. METHODS: Multicenter study including 318 NS patients, categorized as progressors to advanced CKD [estimated glomerular filtration rate (eGFR)] < 30 mL/min/1.73 m2] and slow/non-progressors (eGFR > 30 mL/min/1.73 m2 through the study). We employed Cox regression with progression time as the outcome and APOL1 genotype as the independent variable. We tested this association in the entire cohort and three subgroups; (1) focal segmental glomerulosclerosis (FSGS), (2) steroid-resistant NS (SRNS), and (3) those who underwent kidney biopsy. RESULTS: Nineteen patients (6%) had an HRG. Of these, 47% were self-reported White. Patients with HRG manifested NS at older ages and presented higher frequencies of FSGS and SRNS. HRG patients progressed to advanced CKD more often than low-risk-genotype (LRG) children in the whole NS cohort (p = 0.001) and the three subgroups. In SRNS and biopsied patients, a single risk variant was associated with trends of higher CKD progression risk. CONCLUSIONS: Novel discoveries include a substantial prevalence of HRG among patients self-reported White, worse kidney outcomes in HRG versus LRG children in the FSGS subgroup, and a trend of higher CKD progression risk associated with a single risk variant in the SRNS cohort. These findings suggest APOL1-associated NS extends beyond patients self-reported non-White, the HRG effect is independent of FSGS, and a single risk variant may have a detrimental impact in children with NS.

Eculizumab interruption in atypical hemolytic uremic syndrome due to shortage: analysis of a Brazilian cohort.

BACKGROUND: The risk of eculizumab therapy discontinuation in patients with atypical hemolytic uremic syndrome (aHUS) is unclear. The main objective of this study was to analyze the risk of aHUS relapse after eculizumab interruption due to drug shortage in Brazil. METHODS: We screened all the registered dialysis centers in Brazil (n = 800), willing to participate in the aHUS Brazilian shortage cohort, through electronic mail and formal invitation by the Brazilian Society of Nephrology. We included patients with aHUS whose eculizumab therapy underwent unplanned discontinuation for at least 30 days between January 1st, 2016 and December 31st, 2019 during the maintenance phase of treatment. Relapse was defined by the development of thrombocytopenia, hemolytic anemia, acute kidney injury or thrombotic microangiopathy (TMA) in a kidney biopsy. RESULTS: We analyzed 25 episodes of exposure to risk of relapse, from 24 patients. Median age was 33 (6-53) years, 18 (72%) were female, 9 (36%) had a functioning renal graft, 5 (20%) were undergoing dialysis. CFH variant was found in 8 (32%) episodes. There were 11 relapses. The risk of relapse was 34%, 44.5% and 58% at 114, 150 and 397 days, respectively. No baseline variable was related to relapse in Cox multivariate analysis, including CFH variant. CONCLUSIONS: In this study, the cumulative incidence of aHUS relapse at 397 days was 58% after eculizumab interruption. The presence of complement variant does not seem to be associated with a higher relapse rate. The eculizumab interruption was deemed not safe, considering that the rate of relapse was high.

Complement in Secondary Thrombotic Microangiopathy.

Thrombotic microangiopathy (TMA) is a condition characterized by thrombocytopenia and microangiopathic hemolytic anemia (MAHA) with varying degrees of organ damage in the setting of normal international normalized ratio and activated partial thromboplastin time. Complement has been implicated in the etiology of TMA, which are classified as primary TMA when genetic and acquired defects in complement proteins are the primary drivers of TMA (complement-mediated TMA or atypical hemolytic uremic syndrome, aHUS) or secondary TMA, when complement activation occurs in the context of other disease processes, such as infection, malignant hypertension, autoimmune disease, malignancy, transplantation, pregnancy, and drugs. It is important to recognize that this classification is not absolute because genetic variants in complement genes have been identified in patients with secondary TMA, and distinguishing complement/genetic-mediated TMA from secondary causes of TMA can be challenging and lead to potentially harmful delays in treatment. In this review, we focus on data supporting the involvement of complement in aHUS and in secondary forms of TMA associated with malignant hypertension, drugs, autoimmune diseases, pregnancy, and infections. In aHUS, genetic variants in complement genes are found in up to 60% of patients, whereas in the secondary forms, the finding of genetic defects is variable, ranging from almost 60% in TMA associated with malignant hypertension to less than 10% in drug-induced TMA. On the basis of these findings, a new approach to management of TMA is proposed.

Recommendations from the Brazilian Society of Nephrology regarding the use of cloth face coverings, by chronic kidney patients in dialysis, during the new coronavirus pandemic (Covid-19).

These recommendations were created after the publication of informative note 3/2020- CGGAP/DESF/SAPS/MS, of April 4, 2020, in which the Brazilian Ministry of Health recommended the use of a cloth mask by the population, in public places. Taking into account the necessary prioritization of the provision of Personal Protective Equipment (PPE) for patients with suspected or confirmed disease, as well as for healthcare professionals, the SBN is favorable concerning the wear of cloth masks by chronic kidney patients in dialysis, in public settings, except in the dialysis setting. The present recommendations have eleven items, related to this rationale, the procedures, indications, contraindications, as well as appropriate fabrics for the mask, and hygiene care to be adopted. These recommendations may change, at any time, in the light of new evidence.

Recommendations Of The Brazilian Society Of Nephrology Regarding Pediatric Patients On Renal Replacement Therapy During The Covid-19 Pandemic.

INTRODUCTION: The impact of the new coronavirus (SARS-COV-2) and its worldwide clinical manifestations (COVID-19) imposed specific regional recommendations for populations in need of specialized care, such as children and adolescents with kidney diseases, particularly in renal replacement therapies (RRT). We present the recommendations of the Brazilian Society of Nephrology regarding the treatment of pediatric patients with kidney diseases during the COVID-19 pandemic. METHODS: Articles and documents from medical societies and government agencies on specific recommendations for children on RRT in relation to COVID-19 as well as those focused on epidemiological aspects of this condition in Brazil Were evaluated and analyzed. RESULTS: We present recommendations on outpatient care, transportation to dialysis centers, peritoneal dialysis, hemodialysis, and kidney transplantation in children and adolescents during the COVID-19 pandemic in Brazil. DISCUSSION: Despite initial observations of higher mortality rates in specific age groups (the elderly) and with comorbidities (obese, diabetics, and those with cardiovascular diseases), patients with chronic kidney disease (CKD) on RRT are particularly prone to develop COVID-19. Specific measures must be taken to reduce the risk of contracting SARS-CoV-2 and developing COVID-19, especially during transport to dialysis facilities, as well as on arrival and in contact with other patients.