Abstract Coronavirus disease 2019 (COVID-19) is a rapid-spread infectious disease caused by the SARS-CoV-2 virus, which can culminate in the renin-angiotensin-aldosterone (RAAS) and kallikrein-kinin (KKS) systems imbalance, and in serious consequences for infected patients. This scoping review of published research exploring the RAAS and KKS was undertaken in order to trace the history of the discovery of both systems and their multiple interactions, discuss some aspects of the viral-cell interaction, including inflammation and the system imbalance triggered by SARS-CoV-2 infection, and their consequent disorders. Furthermore, we correlate the effects of continued use of the RAAS blockers in chronic diseases therapies with the virulence and physiopathology of COVID-19. We also approach the RAAS and KKS-related proposed potential therapies for treatment of COVID-19. In this way, we reinforce the importance of exploring both systems and the application of their components or their blockers in the treatment of coronavirus disease.

RESUMO Introdução: O risco de óbito após transplante renal está associado à idade do receptor, presença de comorbidades, condição socioeconômica, às características ambientais locais e ao acesso a serviços de atenção à saúde. Objetivo: Investigar as causas e fatores de risco associados ao óbito nos primeiros cinco anos após o transplante renal. Métodos: Este é um estudo unicêntrico retrospectivo com pareamento dos grupos caso e controle. Resultados: Em uma coorte consecutiva de 1.873 receptores de transplante renal atendidos de 1/1/2007 a 31/12/2009 foram registrados 162 óbitos (grupo caso), correspondendo a uma taxa de sobrevida após cinco anos de 91,4%. Dos óbitos registrados, 25% ocorreram nos primeiros três meses após o transplante. A causa de óbito mais prevalente foi infecção (53%), seguida de doença cardiovascular (24%). Os fatores de risco associados a mortalidade foram histórico de diabetes, tipo e tempo em diálise, desemprego, função tardia do enxerto, número de consultas, número de hospitalizações e tempo de internação hospitalar. Após análise multivariada, apenas o tempo em diálise, o número de consultas e dias de internação permaneceram associados a mortalidade. Os pacientes que foram a óbito tiveram um número não significativamente maior de tratamentos de episódios de rejeição aguda (38% vs. 29%; p = 0,078), maior número médio de eventos adversos por paciente (5,1 ± 3,8 vs. 3,8 ± 2,9; p = 0,194) e TFGe média mais baixa aos três meses (50,8 ± 25,1 vs. 56,7 ± 20,7; p = 0,137) e 48 meses (45,9 ± 23,8 vs. 58,5 ± 20,2; p = 0,368). Conclusão: A presente análise confirmou que nessa população, a infecção foi a principal causa de mortalidade nos primeiros cinco anos após transplante renal. Vários fatores de risco demográficos e socioeconômicos foram associados a mortalidade, a maioria não prontamente modificável.

ABSTRACT Introduction: The risk of death after kidney transplant is associated with the age of the recipient, presence of comorbidities, socioeconomic status, local environmental characteristics and access to health care. Objective: To investigate the causes and risk factors associated with death during the first 5 years after kidney transplantation. Methods: This was a single-center, retrospective, matched case-control study. Results: Using a consecutive cohort of 1,873 kidney transplant recipients from January 1st 2007 to December 31st 2009, there were 162 deaths (case group), corresponding to 5-year patient survival of 91.4%. Of these deaths, 25% occurred during the first 3 months after transplant. The most prevalent cause of death was infectious (53%) followed by cardiovascular (24%). Risk factors associated with death were history of diabetes, dialysis type and time, unemployment, delayed graft function, number of visits to center, number of hospitalizations, and duration of hospital stay. After multivariate analysis, only time on dialysis, number of visits to center, and days in hospital were still associated with death. Patients who died had a non-significant higher number of treated acute rejection episodes (38% vs. 29%, p = 0.078), higher mean number of adverse events per patient (5.1 ± 3.8 vs. 3.8 ± 2.9, p = 0.194), and lower mean eGFR at 3 months (50.8 ± 25.1 vs. 56.7 ± 20.7, p = 0.137) and 48 months (45.9 ± 23.8 vs. 58.5 ± 20.2, p = 0.368). Conclusion: This analysis confirmed that in this population, infection is the leading cause of mortality over the first 5 years after kidney transplantation. Several demographic and socioeconomic risk factors were associated with death, most of which are not readily modifiable.

ABSTRACT Background: The identification of the best strategy to manage cytomegalovirus infection is hampered by uncertainties regarding the risk/benefit ratios of universal prophylaxis versus preemptive therapy, the impact of indirect cytomegalovirus effects and the associated costs. This study investigated the efficacy and safety of targeted preemptive therapy according to perceived risk of cytomegalovirus infection after kidney transplantation. Methods: 144 adult kidney transplant recipients were enrolled in this 12-month study. None received cytomegalovirus pharmacological prophylaxis. Only high risk patients (positive donor/negative recipient (D+/R−), use of induction therapy with antithymocyte globulin, treatment of rejection) received preemptive therapy based on the result of pp65 antigenemia test. Low-risk patients with symptoms related to cytomegalovirus were screened for pp65 antigenemia and treatment initiated if confirmed cytomegalovirus disease. Blinded cytomegalovirus DNAemia was collected weekly during the first three months. Results: The incidence of cytomegalovirus infection was 34% and cytomegalovirus disease was 17%. The incidence was 25% in D+/R−, 69% in those receiving induction with rabbit antithymocite globulin (r-ATG), 46% in those treated for acute rejection, and 28% in low risk patients. By week 3 DNAemia was observed in 30% of patients who were not treated for cytomegalovirus infection/disease, and values ≥2.169 UI/mL showed 61% sensitivity and 85% specificity to detect cytomegalovirus disease (AUC = 0.849 ± 0.042, p < 0.001). Using multivariate analysis, only anti-thymocyte globulin induction was associated with cytomegalovirus infection/disease whereas only expanded donor criteria and renal function at 30 days were associated with renal function 12 months after transplantation. Conclusion: Targeted preemptive therapy in patients with perceived higher risk for cytomegalovirus infection/disease was effective in preventing severe clinical presentation, including tissue invasive and late cytomegalovirus infection. This strategy is associated with direct and indirect cost-savings.