Investigation of the protective effect of boric acid against hepatotoxic and nephrotoxic injury induced by acrylamide in rats / Investigación del efecto protector del ácido bórico contra lesiones hepatotóxicas y nefrotóxicas inducidas por acrilamida en ratas

SUMMARY: To investigate if the administration of boric acid (BA) would exert any protective effect against possible nephrotoxicity and hepatotoxicity induced by the exposure to acrylamide (ACR) in rats. In our study, we used a total of 28 rats that were divided into four equal groups. Group 1: the control group which was not treated with any procedure. Group 2: the ACR group that was administered ACR 50 mg/kg/day via intraperitoneal (i.p) route for 14 days. Group 3: the BA group that was administered BA 200 mg/kg/ day via gavage via peroral (p.o) route for 14 days. Group 4: the ACR+BA group that was administered BA simultaneously with ACR. Total antioxidant and oxidant (TAS/TOS) capacities were measured in all groups at the end of the experiment. In addition, the specimens obtained were evaluated with histopathological examination. Studies showed that the ACR and ACr+BA groups were not significantly different in terms of hepatic TAS level while the TOS level was higher in the ACR group than the ACR+BA group. The groups did not show any significant difference regarding renal TAS and TOS levels. In the histopathological examination of the hepatic tissue, the histopathological injury score of the ACR group was significantly higher than those of the other groups whereas it was significantly lower in the ACR+BA group than the ACR group. Our study concluded that Boric acid had a protective effect against acrylamide- induced hepatotoxicity, but not against nephrotoxicity.

El objetivo de este estudio fue investigar si la administración de ácido bórico (BA) ejercería algún efecto protector frente a la posible nefrotoxicidad y hepatotoxicidad inducida por la exposición a acrilamida (ACR) en ratas. En nuestro estudio, utilizamos un total de 28 ratas que se dividieron en cuatro grupos iguales. Grupo 1: grupo control que no fue tratado. Grupo 2: grupo ACR al que se le administró ACR 50 mg/kg/día por vía intraperitoneal (i.p) durante 14 días. Grupo 3: grupo BA al que se le administró BA 200 mg/kg/día por sonda por vía peroral (p.o) durante 14 días. Grupo 4: grupo ACR+BA al que se administró BA simultáneamente con ACR. Las capacidades antioxidantes y oxidantes totales (TAS/TOS) se midieron en todos los grupos al final del experimento. Además, los especímenes obtenidos fueron evaluados con examen histopatológico. Los estudios demostraron que los grupos ACR y ACr+BA no fueron significativamente diferentes en términos del nivel hepático de TAS, mientras que el nivel de TOS fue mayor en el grupo ACR que en el grupo ACR+BA. Los grupos no mostraron ninguna diferencia significativa con respecto a los niveles renales de TAS y TOS. En el examen histopatológico del tejido hepático, la puntuación de lesión histopatológica del grupo ACR fue significativamente mayor que la de los otros grupos, mientras que fue significativamente menor en el grupo ACR+BA que en el grupo ACR. Nuestro estudio concluyó que el ácido bórico tiene un efecto protector contra la hepatotoxicidad inducida por acrilamida, pero no contra la nefrotoxicidad.

Effects of interleukin-17A on liver and kidney injury and prognosis in septic mice / 中华危重病急救医学

OBJECTIVE@#To explore the effect of interleukin-17A (IL-17A) on liver and kidney injury and prognosis in septic mice.@*METHODS@#A total of 84 SPF male C57BL/6 mice were randomly divided into sham operation group (Sham group), cecal ligation and puncture (CLP) induced sepsis model group (CLP group), and IL-17A intervention group. IL-17A intervention group were then divided into five subgroups according to the dose of IL-17A (0.25, 0.5, 1, 2, 4 μg). Mice in the IL-17A intervention group were intraperitoneally injected with the corresponding dose of IL-17A 100 μL immediately after surgery. The other groups were intraperitoneally injected with 100 μL phosphate buffer solution (PBS). The survival rate of mice was observed at 7 days, and peripheral blood and liver, kidney and spleen tissues were collected. According to the 7-day survival, another 18 mice were randomly divided into Sham group, CLP group, and 1 μg IL-17A intervention group. Peripheral blood samples were collected at 12 hours and 24 hours after CLP, and the mice were sacrificed to obtain liver, kidney, and spleen tissues. The behavior and abdominal cavity of each group were observed. The levels of peripheral blood liver and kidney function indexes and inflammatory factors were detected. The histopathological changes of liver and kidney were observed under light microscope. The peripheral blood and spleen tissues were inoculated in the medium, the number of bacterial colonies was calculated, and the bacterial migration of each group was evaluated in vitro.@*RESULTS@#Except for the Sham group, the 7-day survival rate of mice in the 1 μg IL-17A intervention group was the highest (75.0%), so this condition was selected as the intervention condition for the subsequent study. Compared with Sham group, the liver and kidney functions of CLP group were significantly damaged at each time point after operation. Alanine aminotransferase (ALT), aspartate aminotransferase (AST), blood urea nitrogen (BUN) and serum creatinine (SCr) reached the peak at 24 hours after operation, and the liver and kidney pathological scores reached the peak at 7 days after operation, the levels of inflammatory cytokines interleukin (IL-17A, IL-6, IL-10) reached the peak at 12 hours after operation, and tumor necrosis factor-α (TNF-α) reached the peak at 24 hours after operation. In addition, a large number of bacteria proliferated in the peripheral blood and spleen, which reached the peak on day 7. Compared with the CLP group, exogenous administration of 1 μg IL-17A significantly delayed the rising trend of each index in the early stage of sepsis [24-hour ALT (U/L): 166.95±5.20 vs. 271.30±6.11, 24-hour AST (U/L): 599.42±7.25 vs. 1 013.27±3.37, 24-hour BUN (mg/L): 815.4±26.3 vs. 1 191.2±39.4, 24-hour SCr (μmol/L): 29.34±0.87 vs. 60.75±3.83, 7-day liver pathological score: 2.50 (2.00, 3.00) vs. 9.00 (8.50, 9.00), 7-day kidney pathological score: 1.00 (1.00, 2.00) vs. 5.00 (4.50, 5.00), 12-hour IL-17A (ng/L): 105.21±0.31 vs. 111.28±1.37, 12-hour IL-6 (ng/L): 83.22±1.01 vs. 108.88±0.99, 12-hour IL-10 (ng/L): 731.54±3.04 vs. 790.25±2.54, 24-hour TNF-α (μg/L): 454.67±0.66 vs. 576.18±0.76, 7-day peripheral blood colony count (CFU/mL): 600 (400, 600) vs. 4 200 (4 200, 4 300), 7-day spleen tissue colony count (CFU/g): 4 600 (4 400, 4 600) vs. 23 400 (23 200, 23 500), all P < 0.05].@*CONCLUSIONS@#Appropriate dose (1 μg) of exogenous IL-17A can reduce the lethal inflammatory response induced by CLP and improve the ability of bacterial clearance, thereby alleviating liver and kidney injury and improving the 7-day survival rate of septic mice.

Association between Serum Uric Acid and the Early Marker of Kidney Function Decline among Chinese Middle-Aged and Older Population: Evidence from the China Health and Retirement Longitudinal Study / 生物医学与环境科学（英文）

OBJECTIVE@#To evaluate the association between serum uric acid (SUA) and kidney function decline.@*METHODS@#Data was obtained from the China Health and Retirement Longitudinal Study on the Chinese middle-aged and older population for analysis. The kidney function decline was defined as an annual estimated glomerular filtration rate (eGFR) decrease by > 3 mL/min per 1.73 m 2. Multivariable logistic regression was applied to determine the association between SUA and kidney function decline. The shape of the association was investigated by restricted cubic splines.@*RESULTS@#A total of 7,346 participants were included, of which 1,004 individuals (13.67%) developed kidney function decline during the follow-up of 4 years. A significant dose-response relation was recorded between SUA and the kidney function decline ( OR 1.14, 95% CI 1.03-1.27), as the risk of kidney function decline increased by 14% per 1 mg/dL increase in SUA. In the subgroup analyses, such a relation was only recorded among women ( OR 1.22, 95% CI 1.03-1.45), those aged < 60 years ( OR 1.22, 95% CI 1.05-1.42), and those without hypertension and without diabetes ( OR 1.22, 95% CI 1.06-1.41). Although the dose-response relation was not observed in men, the high level of SUA was related to kidney function decline ( OR 1.83, 95% CI 1.05-3.17). The restricted cubic spline analysis indicated that SUA > 5 mg/dL was associated with a significantly higher risk of kidney function decline.@*CONCLUSION@#The SUA level was associated with kidney function decline. An elevation of SUA should therefore be addressed to prevent possible kidney impairment and dysfunction.

Short- and mid- term impact of tobacco smoking on donor renal function following living kidney donation at a tertiary referral hospital

Background: The negative impact of tobacco smoking on renal function has been widely studied. However, there is limited knowledge about the effect of smoking on pre-operative and post-operative renal function in living kidney donors. Objective: The objective of the study was to evaluate the short- and mid-term impact of smoking on donor renal function. Methods: This is a retrospective study of 308 patients who underwent living donor nephrectomy (LDN) at a tertiary referral hospital. We compared baseline characteristics as well as functional outcomes following LDN according to history of tobacco smoking. Estimated glomerular filtration rate (eGFR) was calculated with the modification of diet in renal disease equation in 6 time periods: pre-operative, 1 week, 1 month, 6 months, 12 months, and 24 months after surgery. We performed a Kaplan-Meier analysis for chronic kidney disease (CKD) outcome and binary logistic regression analysis to identify risk factors associated with CKD at 24 months of follow-up. Results: Among donors, 106 (34.4%) reported a smoking history before nephrectomy. Smoking donors had worse pre-operative eGFR than non-smokers (90 ± 26.3 mL/min/1.73m2 vs. 96 ± 27 mL/min/1.73 m2, respectively; p = 0.02) and lower eGFR at 1 week (p = 0.01), 1 month (p ≤ 0.01), 6 months (p = 0.01), and 12 months (p = 0.01) after LDN. Tobacco smoking (OR 3.35, p ≤ 0.01) and age ≥ 40 years at donation (OR 6.59, p ≤ 0.01) were associated with post-operative development of CKD at 24 months after LDN. Conclusions: Living kidney donors with a tobacco smoking history had an increased risk of developing chronic kidney disease following nephrectomy. Smoking-cessation strategies should be implemented.

Use of medicines for covid-19 treatment in patients with loss of kidney function: a narrative review / Medicamentos utilizados no tratamento da covid-19 em pacientes com perda da capacidade funcional renal: uma revisão rápida da literatura

ABSTRACT Covid-19 has been identified as the cause of acute respiratory disease with interstitial and alveolar pneumonia, but it can affect several organs, such as kidneys, heart, blood, nervous system and digestive tract. The disease-causing agent (Sars-CoV-2) has a binding structure to the angiotensin-converting enzyme 2 (ACE2) receptor, enabling entry into cells that express ACE2, such as the pulmonary alveolar epithelial cells. However, studies also indicate the possibility of damage to renal cells, since these cells express high levels of ACE2. Currently, there is no evidence to indicate a specific treatment for covid-19. Several drugs have been used, and some of them may have their excretion process altered in patients with abnormal kidney function. To date, there are no studies that assist health professionals in adjusting the dose of these drugs. Thus, this study aims to review and discuss the topic, taking into account factors associated with kidney injury in covid-19, as well as pharmacokinetic aspects and dose recommendations of the main drugs used for covid-19.

RESUMO A covid-19 foi identificada como a causa de doença respiratória aguda com pneumonia intersticial e alveolar, mas que pode afetar vários órgãos, como rim, coração, sangue, sistema nervoso e trato digestivo. O agente causador da doença (Sars-CoV-2) tem uma estrutura de ligação ao receptor da enzima de conversão da angiotensina 2 (ACE2), permitindo a entrada em células que expressam ACE2, como as células epiteliais alveolares pulmonares. Porém, estudos também indicam a possibilidade de lesão das células renais, uma vez que essas células expressam altos níveis de ACE2. Atualmente, não existem evidências para a indicação de um tratamento específico para a covid-19. Vários medicamentos vêm sendo utilizados, e alguns podem ter o processo de eliminação alterados em pacientes com comprometimento renal. Até o momento, não há estudos que auxiliem os profissionais de saúde no ajuste de dose desses medicamentos. Assim, este estudo tem como objetivo revisar e discutir o tema, levando em consideração os fatores relacionados à lesão renal na covid-19, bem como aspectos farmacocinéticos e recomendações de doses dos principais medicamentos utilizados para covid-19.

COVID-19 and Kidney: a narrative review / COVID-19 e os rins: uma revisão narrativa

Abstract COVID-19 is a pandemic associated with systemic clinical manifestations. In this study, we aimed to present a narrative review on kidney involvement in COVID-19. Kidney involvement could be derived from direct cytopathic effects, immunological mechanisms, indirect effects on renal tissue through other mediators, and dysfunction or injury of other organs. The evolution of COVID-19 may be complicated with acute kidney injury (AKI) in a significant percentage of patients, and renal dysfunction seems to be associated with worse prognosis. Patients with chronic kidney disease (CKD) seem to be more susceptible to the severe forms of COVID-19. Patients with renal replacement therapy (RRT) are also a vulnerable population as consequence of their advanced age, underlying comorbidities, impaired immune response, and clustering in hemodialysis centers, with requirements for frequent contact with healthcare services. Kidney transplant patients may be at high-risk due to long-term immunosuppression and comorbidities, hence, managing immunosuppression is imperative. Lastly, renal replacement therapy may be required during COVID-19, and different modalities are discussed based on clinical findings and laboratorial aspects. Therefore, COVID-19 seems to affect kidney by different mechanisms, which contributes for AKI development and increases the severity of the disease. Also, patients with CKD and kidney transplant recipients are at higher risk for COVID-19 and mortality.

Resumo COVID-19 é uma pandemia associada a manifestações clínicas sistêmicas. Neste estudo, apresenta-se revisão narrativa acerca do envolvimento renal na COVID-19. Envolvimento renal parece ser relacionado a efeitos citopáticos diretos, mecanismos imunológicos, efeitos indiretos de outros mediadores no tecido renal, além de disfunção e lesão de outros órgãos. A evolução da COVID-19 pode ser complicada por lesão renal aguda (LRA) em percentual significativo dos pacientes, e a disfunção renal parece ser associada a pior prognóstico. Pacientes com doença renal crônica (DRC) parecem ser mais suscetíveis a formas severas da COVID-19. Pacientes em terapia de substituição renal (TSR) contínua também constituem população vulnerável em razão de idade avançada, comorbidades subjacentes, resposta imune disfuncional e aglomeração em unidades de diálise, com necessidade de visitas frequentes aos serviços de saúde. Pacientes transplantados renais podem estar em alto risco dadas imunossupressão a longo prazo e comorbidades; assim, o manejo da imunossupressão é mandatório. Finalmente, TSR pode ser necessária durante a COVID-19, e diferentes modalidades são discutidas conforme manifestações clínicas e aspectos laboratoriais. Assim, COVID-19 parece acometer os rins por diferentes mecanismos, os quais contribuem para o desenvolvimento de LRA e aumento da severidade da doença. Ainda, pacientes com DRC e transplantados renais apresentam elevado risco para desenvolvimento de COVID-19 e de mortalidade.

Renal changes in COVID-19 infection

SUMMARY The COVID-19 (SARS-CoV-2) infection started in China, Wuhan City, Hubei Province, in December 2019, and it was declared a pandemic in mid-March 2020, caused by a new coronavirus strain called SARS-CoV-2. The pathogenesis of kidney injury attributed to SARS- CoV-2 is not well defined yet. Observations show that the kidney damage caused by the new virus mutation is mainly tubular, with impairment of glomerular filtration and high levels of urea and creatinine. A study with seriously ill patients with COVID-19 showed that acute kidney injury was present in 29%. In the face of this evidence, based on recent studies, we can see the great renal contribution as an impact factor in the evolution of COVID-19, not just as a complicator of severity, but maybe part of the initial cascade of the process, requiring a deeper analysis using conventional biomarkers of kidney injury and more aggressive clinical intervention in patients at risk, in an attempt to reduce mortality.

RESUMO Infecção pelo COVID-19 (SARS-CoV-2) começou na China, cidade de Wuhan, província de Hubei, em dezembro de 2019, e foi declarada pandemia em meados de março de 2020, causada por uma nova cepa de coronavírus chamada SARS-CoV-2. A patogênese da lesão renal atribuída à SARS-CoV-2 ainda não está bem definida. Observações mostram que o dano renal causado pela nova mutação viral é principalmente tubular, com comprometimento da filtração glomerular e apresentação de altos níveis de uréia e creatinina. Estudo com pacientes gravemente enfermos com COVID-19 mostrou que a lesão renal aguda estava presente em 29%. Diante dessas evidências, com base em estudos recentes, podemos ver a grande contribuição renal como um fator de impacto na evolução do COVID-19, não apenas como um complicador da gravidade, mas talvez como parte da cascata inicial do processo, exigindo uma investigação de análise mais profunda usando biomarcadores convencionais de lesão renal e intervenção clínica mais agressiva em pacientes em risco, na tentativa de reduzir a mortalidade.

Non-recovery of renal function is a strong independent risk factor associated with mortality in AKI patients / A não recuperação da função renal é um forte fator de risco independente associado à mortalidade em pacientes com LRA

ABSTRACT Introduction: Acute kidney injury (AKI) is a recurrent complication in the intensive care unit (ICU) and is associated with negative outcomes. Objective: To investigate factors associated with mortality in critically ill AKI patients in a South Brazilian ICU. Methods: The study was observational retrospective involving AKI patients admitted to the ICU between January 2011 and December 2016 of at least 18 years old upon admission and who remained in the ICU at least 48 hours. Comparisons between selected characteristics of survivor and non-survivor groups were done using univariate analysis; multivariate logistic regression was applied to determine factors associated with patient mortality. Results: Of 838 eligible patients, 613 participated in the study. Men represented the majority (61.2%) of the patients, the median age was 53 years, and the global mortality rate was 39.6% (n= 243). Non-recovery of renal function after AKI (OR= 92.7 [38.43 - 223.62]; p <0.001), major surgery-associated AKI diagnosis (OR= 16.22 [3.49 - 75.38]; p <0.001), and the use of vasoactive drugs during the ICU stay (OR = 11.49 [2.46 - 53.70]; p <0.002) were the main factors independently associated with patient mortality. Conclusion: The mortality rate observed in this study was similar to that verified in other centers. Non-recovery of renal function was the variable most strongly associated with patient mortality, suggesting that the prevention of factors that aggravate or maintain the AKI episode should be actively identified and mitigated, possibly constituting an important strategy to reduce mortality in AKI patients.

RESUMO Introdução: A lesão renal aguda (LRA) é uma complicação recorrente na unidade de terapia intensiva (UTI), e está associada a desfechos desfavoráveis. Objetivo: Investigar fatores associados à mortalidade em pacientes com LRA, criticamente enfermos em uma UTI do Sul do Brasil. Métodos: O estudo foi retrospectivo observacional, envolvendo pacientes com LRA internados na UTI entre janeiro de 2011 e dezembro de 2016, com pelo menos 18 anos de idade na admissão e que permaneceram na UTI por pelo menos 48 horas. Comparações entre características selecionadas de grupos sobreviventes e não sobreviventes foram feitas usando análise univariada; regressão logística multivariada foi aplicada para determinar fatores associados à mortalidade dos pacientes. Resultados: Dos 838 pacientes elegíveis, 613 participaram do estudo. Os homens representaram a maioria (61,2%) dos pacientes, a idade média foi de 53 anos e a taxa de mortalidade global foi de 39,6% (n = 243). Não recuperação da função renal após LRA (OR = 92,7 [38,43 - 223,62]; p <0,001), diagnóstico de LRA associado à cirurgia (OR = 16,22 [3,49 - 75,38]; p <0,001) e uso de drogas vasoativas durante a internação na UTI (OR = 11,49 [2,46 - 53,70]; p <0,002) foram os principais fatores independentemente associados à mortalidade dos pacientes. Conclusão: A taxa de mortalidade observada neste estudo foi semelhante à verificada em outros centros. A não recuperação da função renal foi a variável mais fortemente associada à mortalidade dos pacientes, sugerindo que a prevenção de fatores que agravam ou mantêm o episódio de LRA deve ser ativamente buscada e incentivada, possivelmente constituindo uma estratégia importante para reduzir a mortalidade em pacientes com LRA.

El riñón del niño prematuro: riesgos a largo plazo / The kidney of the premature child: long-term risks

Resumen: El recién nacido prematuro se enfrenta a las condiciones extrauterinas con sistemas aún inmaduros, tanto anatómica como fisiológicamente. El riñón termina de desarrollarse a finales del tercer trimes tre del embarazo, por lo que está especialmente expuesto a alterar su desarrollo normal en caso de nacer en forma prematura. Esta situación puede condicionar, entre otras consecuencias, una menor masa renal funcional y cambios microvasculares que representan un riesgo elevado de hipertensión arterial y daño renal crónico en el largo plazo. En el presente artículo se analiza la evidencia existente actual sobre estos riesgos en los prematuros y se ofrece un esquema de seguimiento de estos niños desde el punto de vista nefrológico.

Abstract: The premature newborn faces extrauterine conditions with some systems still immature, both ana tomically and physiologically. The kidney finishes developing at the end of the third trimester of pregnancy, so it is especially exposed to alter its normal development if preterm birth occurs. This si tuation may condition, among other consequences, a lower functional renal mass and microvascular changes comprising a high risk of chronic kidney disease in the long term and arterial hypertension. This article analyzes the current evidence on these risks in premature infants and offers a nephrology follow-up scheme of these children.

Rare inherited kidney diseases: an evolving field in Nephrology / Doenças renais hereditárias raras: um campo em evolução na Nefrologia

Abstract There are more than 150 different rare genetic kidney diseases. They can be classified according to diagnostic findings as (i) disorders of growth and structure, (ii) glomerular diseases, (iii) tubular, and (iv) metabolic diseases. In recent years, there has been a shift of paradigm in this field. Molecular testing has become more accessible, our understanding of the underlying pathophysiologic mechanisms of these diseases has evolved, and new therapeutic strategies have become more available. Therefore, the role of nephrologists has progressively shifted from a mere spectator to an active player, part of a multidisciplinary team in the diagnosis and treatment of these disorders. This article provides an overview of the recent advances in rare hereditary kidney disorders by discussing the genetic aspects, clinical manifestations, diagnostic, and therapeutic approaches of some of these disorders, named familial focal and segmental glomerulosclerosis, tuberous sclerosis complex, Fabry nephropathy, and MYH-9 related disorder.

Resumo As doenças renais genéticas raras compreendem mais de 150 desordens. Elas podem ser classificadas segundo achados diagnósticos como (i) distúrbios do crescimento e estrutura, (ii) doenças glomerulares, (iii) tubulares e (iv) metabólicas. Nos últimos anos, houve uma mudança de paradigma nesse campo. Os testes moleculares tornaram-se mais acessíveis, nossa compreensão sobre os mecanismos fisiopatológicos subjacentes a essas doenças evoluiu e novas estratégias terapêuticas foram propostas. Portanto, o papel do nefrologista mudou progressivamente de mero espectador a participante ativo, parte de uma equipe multidisciplinar, no diagnóstico e tratamento desses distúrbios. O presente artigo oferece um panorama geral dos recentes avanços a respeito dos distúrbios renais hereditários raros, discutindo aspectos genéticos, manifestações clínicas e abordagens diagnósticas e terapêuticas de alguns desses distúrbios, mais especificamente a glomeruloesclerose segmentar e focal familiar, complexo da esclerose tuberosa, nefropatia de Fabry e doença relacionada ao MYH9.

Cardiometabolic risk factors associated with renal function in apparently healthy young students: a cross-sectional study

ABSTRACT Background: Cardiometabolic risk factors (CMRFs) appear decades before developing chronic kidney disease (CKD) in adulthood. Objective: The objective of the study was to identify the prevalence and association between CMRFs and kidney function in apparently healthy young adults (18-25 years old). Methods: We included 5531 freshman year students. Data collected on CMRFs included central obesity, high body mass index (hBMI >25), blood pressure, glycemia, lipids, uric acid (UA >6.8 mg/dL), and insulin. Glomerular filtration rate (GFR) was estimated by CKD-Epidemiology Collaboration formula. We used logistic regression and a log linear for odds ratio (OR) (95% confidence level) and probabilities. Results: The presence of any CMRF was observed in 78% (4312) of individuals; GFR ≥120/130 mL/min/1.73 m2sc was found in 33%, GFR <90 mL/min/1.73 m2sc in 3%, and proteinuria in 3%. Factors associated with high GFR were hBMI (OR 1.3 [1.14, 1.47]), UA (OR 0.2 [0.15, 0.26]), high-density lipoprotein (HDL) (OR 1.4 [1.2, 1.6]), and insulin resistance (OR 1.3 [1.05, 1.7]). CMRF associated with low GFR was UA (OR 1.8 [1.3, 2.6]), low-density lipoprotein cholesterol (OR 1.66 [1.05, 2.6]), and proteinuria (OR 3.4 [2.07, 5.7]). Proteinuria was associated with high UA (OR 1.59 [1.01, 2.5]) and hypercholesterolemia (OR 1.8 [1.03, 3.18]). The sole presence of hBMI+UA predicted low GFR with p = 0.6 and hBMI+UA+low HDL predicted proteinuria with p = 0.55. Conclusions: CMRFs were highly prevalent among this freshman student population and were associated with proteinuria and GFR abnormalities. Future studies should focus on public health programs to prevent or delay the development of CKD.

Renal sympathetic denervation for resistant hypertension: where do we stand after more than a decade / Denervação simpática renal para hipertensão resistente: situação depois de mais de uma década

Abstract Despite the current availability of safe and efficient drugs for treating hypertension, a substantial number of patients are drug-resistant hypertensives. Aiming this condition, a relatively new approach named catheter-based renal denervation was developed. We have now a clinically relevant time window to review the efficacy of renal denervation for treating this form of hypertension. This short review addresses the physiological contribution of renal sympathetic nerves for blood pressure control and discusses the pros and cons of renal denervation procedure for the treatment of resistant hypertension.

Resumo Em que pese a atual disponibilidade de medicamentos seguros e eficientes para o tratamento da hipertensão, um número significativo de pacientes sofre de hipertensão arterial resistente a tratamento medicamentoso. Em vista dessa condição, foi desenvolvida uma abordagem relativamente nova, denominada denervação renal por cateter. Dispomos atualmente de uma janela de tempo clinicamente relevante para analisar a eficácia da denervação renal no tratamento dessa modalidade de hipertensão. A presente revisão aborda a contribuição fisiológica dos nervos renais simpáticos no controle da pressão arterial e discute os prós e contras do procedimento de denervação renal no tratamento da hipertensão resistente.

Correlation between amyloid deposits affecting renal compartments and glomerular filtration rate during renal biopsy in a renal amyloidosis case series

Amyloidosis comprises a group of disorders that accumulate modified autologous proteins in organs, mainly the kidneys. Few studies have addressed the amyloid compartmental distribution and associated clinical outcomes. The aim of this study was to present a case series of renal amyloidosis correlating histopathological data with glomerular filtration rate (GFR) during kidney biopsy. We studied 53 cases reviewed by nephropathologists from 2000 to 2018 in a single kidney biopsy center in Brazil. GFR was estimated using the CKD-EPI formula. Cases were divided into Group A ≥60 and Group B <60 mL·min−1·(1.73 m2)−1 using the estimated GFR during kidney biopsy. Semiquantitative histopathological study was performed, including extension and distribution of amyloid deposits by compartments (glomeruli, tubulointerstitial tissue, and vessels). Statistical analyses were made to understand associations with lower GFR. No difference was seen for age, gender, proteinuria, hematuria, subtype of amyloid protein, arteriosclerosis, interstitial fibrosis/infiltrate, or glomerular and interstitial amyloid deposits. After a previous P value <0.1 in the descriptive analysis, the following variables were selected: globally sclerotic glomeruli, high blood pressure, and the extension of vascular amyloid deposition. A binary logistic regression model with GFR as the dependent variable showed history of hypertension and vascular amyloid to be robust and independent predictors of Group B <60 mL·min−1·(1.73 m2)−1. Beyond the histopathologic diagnosis of amyloidosis, a semiquantitative approach on renal biopsy could provide new insights. Vascular amyloid is an independent predictor of renal dysfunction in cases of renal amyloidosis.

SGLT-2 inhibitors in diabetes: a focus on renoprotection

SUMMARY Type 2 diabetes mellitus is an important public health problem, with a significant impact on cardiovascular morbidity and mortality and an important risk factor for chronic kidney disease. Various hypoglycemic therapies have proved to be beneficial to clinical outcomes, while others have failed to provide an improvement in cardiovascular and renal failure, only reducing blood glucose levels. Recently, sodium-glucose cotransporter-2 (SGLT2) inhibitors, represented by the empagliflozin, dapagliflozin, and canagliflozin, have been showing satisfactory and strong results in several clinical trials, especially regarding the reduction of cardiovascular mortality, reduction of hospitalization due to heart failure, reduction of albuminuria, and long-term maintenance of the glomerular filtration rate. The benefit from SGLT2 inhibitors stems from its main mechanism of action, which occurs in the proximal tubule of the nephron, causing glycosuria, and a consequent increase in natriuresis. This leads to increased sodium intake by the juxtaglomerular apparatus, activating the tubule glomerular-feedback and, finally, reducing intraglomerular hypertension, a frequent physiopathological condition in kidney disease caused by diabetes. In addition, this class of medication presents an appropriate safety profile, and its most frequently reported complication is an increase in the incidence of genital infections. Thus, these hypoglycemic agents gained space in practical recommendations for the management of type 2 diabetes mellitus and should be part of the initial therapeutic approach to provide, in addition to glycemic control, cardiovascular outcomes, and the renoprotection in the long term.

Mesenchymal stem cell therapy in acute kidney injury (AKI): review and perspectives

SUMMARY INTRODUCTION: Acute kidney injury (AKI) is highly prevalent today. It has a multifactorial aetiology and affects people of all ages, genders and ethnicities. Its treatment is essentially supportive of renal function substitution, so new treatment alternatives such as mesenchymal stem cell therapy (MSCs) should be investigated. METHODS: This review encompasses our understanding of the main mechanisms of action of MSCs in preclinical models of AKI by renal pedicle clamping ischemia-reperfusion, chemotherapy (cisplatin) and kidney transplantation in small and large animals, as well as outcomes in patients with AKI due to ischemia and kidney transplantation. RESULTS: Cellular therapy with MSCs has benefits in preclinical studies of AKI through various mechanisms, such as anti-inflammatory, antiapoptotic, oxidative anti-stress, antifibrotic, immunomodulatory and proangiogenic. In humans, MSC therapy is safe and effective. However, the challenges of MSC cell therapy include investigating protocols about the optimal dose of these cells, the route and frequency of appropriate administration, and the design of further biodistribution studies over a long follow-up period. In addition, a better understanding of molecular signalling and cellular interactions in the microenvironment of each organ and tissue is needed in order to define the best time to administer MSCs. Another challenge would be to mitigate the heterogeneity of the profile of cultured MSCs through preconditioning approaches. CONCLUSIONS: Cellular therapy with MSCs is very promising and should be part of the treatment of AKI patients in combination with other approaches already available, helping to accelerate recovery and/or slow the progression to chronic kidney disease. Randomized, multicentre controlled studies are needed to develop robust protocols that validate population-based cell therapy with MSCs.

Estudo da morfologia e status oxidativo em rim de ratos com nefropatia isquêmica após tratamento com células-tronco mesenquimais de tecido adiposo / Study of morphology and oxidative status in kidney of rats with ischemic nephropathy after treatment with adipose tissue mesenchymal stem cells

A nefropatia isquêmica é uma doença renal crônica provocada pela redução do fluxo sanguíneo renal que pode progredir para a doença renal terminal, cujo tratamentos disponíveis se baseiam em terapias substitutivas da função renal, como diálise ou transplante renal. No entanto, devido ao alto custo dos tratamentos e a carência de órgãos, se faz necessária a busca por novas terapias, como as células-tronco (CT). Apesar do potencial terapêutico das CT em doenças crônicas, não está claro se essas células mantêm seus efeitos benéficos em órgãos lesionados por tempo prolongado. O objetivo desse estudo foi avaliar os efeitos precoces e tardios do tratamento com células-tronco adiposas (CTA) sobre a morfologia e o status oxidativo em rins de ratos com nefropatia isquêmica. A isquemia renal foi induzida pelo modelo 2rins-1clip (2R1C) e, depois de um mês da clipagem da artéria renal, foram injetadas 106 células-tronco na região subscapsular do rim afetado. Após 15 e 30 dias da injeção das CTA, a morfologia renal foi verificada por meio da análise macroscópica, microscópica e ultraestrutural. Além disso, o status oxidativo foi avaliado no tecido renal através da mensuração da atividade das enzimas antioxidantes catalase e glutationa peroxidase; e de marcadores biológicos de dano oxidativo, como proteínas carboniladas, 3-Nitrotirosina e 4-Hidroxinonenal. Por imunoperoxidase foi possível localizar as células-tronco adiposas GFP+ foram rastreadas e encontradas tanto 15 dias, quanto 30 dias após a injeção na região subcapsular. A restauração da arquitetura renal foi evidenciada 15d após o uso das células, onde detectamos redução na deposição de fibras colágenas no parênquima renal, o que não foi observado 30d após o uso das células. Os resultados também foram confirmados através da análise da ultraestrutura renal que mostraram restauração da arquitetura renal no grupo de 15d, não evidenciada no grupo de 30d. Quanto a análise do status oxidativo, somente os animais com nefropatia isquêmica mais prolongada apresentaram estresse oxidativo com redução da atividade da enzima antioxidante catalase no tecido renal. Além disso, foi observado dano proteico e lipídico, sem melhora dessa condição nos animais 30d após o tratamento com as células-tronco. No modelo de nefropatia isquêmica avaliado, o tratamento com CTA mostrou benefícios na morfologia renal a curto prazo, mas não tardiamente, apesar da permanência dessas células no tecido. Acreditamos que o estresse oxidativo, evidenciado somente no tecido renal com isquemia mais prolongada, possa ter dificultado a ação das células-tronco, contribuindo para tais achados. Esses resultados abrem perspectivas para o aprofundamento do estudo quanto à caracterização dos mecanimos de ação das CTA nas respostas anti-fibrogênicas, assim como o estabelecimento do número, frequência, vias de administração e melhor momento para uso dessas células no tratamento de doenças renais crônicas.

Ischemic nephropathy is a chronic kidney disease caused by reduced kidney blood flow that can progress to end stage kidney disease, whose available treatments are based on kidney function replacement therapies, such as dialysis or kidney transplantation. However, due to the high cost of treatments and the lack of organs, it is necessary to search for new therapies, such as stem cells (SC). Despite the therapeutic potential of SC in chronic diseases, it is unclear whether these cells maintain their beneficial effects on injured organs for a long time. The aim of this study was to evaluate the early and late effects of adipose-derived stem cells (ADSC) treatment on the morphology and oxidative status in kidneys of rats with ischemic nephropathy. Renal ischemia was induced by the 2kidneys-1clip (2K1C) model and, after a month of clipping the renal artery, 106 stem cells were injected into the subscapsular region of the affected kidney. After 15 and 30 days of ADSC injection, renal morphology was verified by macroscopic, microscopic, and ultrastructural analysis. In addition, oxidative status was assessed in renal tissue by measuring the activity of the antioxidant enzymes catalase and glutathione peroxidase; and biological markers of oxidative damage, such as carbonylated proteins, 3-nitrotyrosine and 4-hydroxynonenal. By immunoperoxidase, it was possible to locate GFP + adipose-derived stem cells that were tracked and found both 15 days and 30 days after injection in the subcapsular region. The restoration of the renal architecture was evidenced 15d after the use of the cells, where we detected a reduction in the deposition of collagen fibers in the renal parenchyma, which was not observed 30d after the use of the cells. The results were also confirmed by analyzing the renal ultrastructure, which showed restoration of the renal architecture in the 15d group, not evidenced in the 30d group. Regarding the analysis of oxidative status, only animals with more prolonged ischemic nephropathy presented oxidative stress with reduced activity of the antioxidant enzyme catalase in renal tissue. In addition, protein and lipid damage was observed, with no improvement in this condition in the animals 30d after treatment with stem cells. In the evaluated ischemic nephropathy model, treatment with ADSC showed benefits in renal morphology in the short term, but not late, despite the permanence of these cells in the tissue. We believe that oxidative stress, evidenced only in renal tissue with more prolonged ischemia, may have hindered the action of stem cells, contributing to such findings. These results open perspectives for further study on the characterization of ADSC mechanisms of action in anti-fibrogenic responses, as well as the establishment of the number, frequency, routes of administration and the best time to use these cells in the treatment of chronic kidney diseases.

Metabolic and volume status evaluation of hemodialysis patients with and without residual renal function in the long interdialytic interval / Avaliação metabólica e volêmica no maior intervalo interdialítico de pacientes em hemodiálise com e sem função renal residual

Abstract Introduction: It is unclear whether residual renal function (RRF) in dialysis patients can attenuate the metabolic impact of the long 68-hour interdialytic interval, in which water, acid, and electrolyte accumulation occurs. Objective: to evaluate serum electrolyte levels, water balance, and acid-base status in dialytic patients with and without RRF over the long interdialytic interval (LII). Methodology: this was a single-center, cross-sectional, and analytical study that compared patients with and without RRF, defined by diuresis above 200 mL in 24 hours. Patients were weighed and serum samples were collected for biochemical and gasometric analysis at the beginning and at the end of the LII. Results: 27 and 24 patients with and without RRF were evaluated, respectively. Patients without RRF had a higher increase in serum potassium during the LII (2.67 x 1.14 mEq/L, p < 0.001), reaching higher values at the end of the study (6.8 x 5.72 mEq/L, p < 0.001) and lower pH value at the beginning of the interval (7.40 x 7.43, p = 0.018). More patients with serum bicarbonate < 18 mEq/L (50 x 14.8%, p = 0.007) and mixed acid-base disorder (57.7 x 29.2%, p = 0.042), as well as greater interdialytic weight gain (14.67 x 8.87 mL/kg/h, p < 0.001) and lower natremia (137 x 139 mEq/L, p = 0.02) at the end of the interval. Calcemia and phosphatemia were not different between the groups. Conclusion: Patients with RRF had better control of serum potassium, sodium, acid-base status, and volemia throughout the LII.

Resumo Introdução: Não se sabe ao certo se a função renal residual (FRR) de pacientes dialíticos pode atenuar o impacto metabólico do maior intervalo interdialítico (MII) de 68 horas, no qual ocorre acúmulo de volume, ácidos e eletrólitos. Objetivo: Avaliar os níveis séricos de eletrólitos, balanço hídrico e status ácido-básico de pacientes dialíticos com e sem FRR ao longo do MII. Metodologia: Tratou-se de estudo unicêntrico, transversal e analítico, que comparou pacientes com e sem FRR, definida como diurese acima de 200 mL em 24 horas. Para tal, os pacientes foram pesados e submetidos à coleta de amostras séricas para análise bioquímica e gasométrica no início e fim do MII. Resultados: Foram avaliados 27 e 24 pacientes com e sem FRR, respectivamente. Pacientes sem FRR apresentaram maior aumento de potássio sérico durante o MII (2,67 x 1,14 mEq/L, p < 0,001) atingindo valores mais elevados no fim (6,8 x 5,72 mEq/L, p < 0,001); menor valor de pH no início do intervalo (7,40 x 7,43, p = 0,018), maior proporção de pacientes com bicarbonato sérico < 18 mEq/L (50 x 14,8 %, p = 0,007) e distúrbio ácido-básico misto (70,8 x 42,3 %, p = 0,042), além de maior ganho de peso interdialítico (14,67 x 8,87 mL/kg/h, p < 0,001) e menor natremia (137 x 139 mEq/L, p = 0,02) no fim do intervalo. A calcemia e fosfatemia não foram diferentes entre os grupos. Conclusão: Pacientes com FRR apresentaram melhor controle dos níveis séricos de potássio, sódio, status ácido-básico e da volemia ao longo do MII.

Kidney transplantation with donors in severe acute kidney injury. Should we use these organs? Retrospective Case Series / Transplante renal com doadores em lesão renal aguda severa. Devemos utilizar esses órgãos? Série de casos retrospectiva

ABSTRACT Introduction: The number of incident and prevalent patients on dialysis has increased, as well as the number of candidates for renal transplantation in Brazil, without a proportional increase in the number of organ donors. The use of expanded kidneys, as to renal function, may be an alternative to increase the supply of organs. Objective: to discuss the feasibility of using expanded kidneys for renal function, which are in severe acute renal injury. Methods: All cases of renal transplantation of deceased donors performed at the Hospital das Clínicas de Botucatu of UNESP, from January 2010 to June 2018, totaling 732 cases were evaluated. Cases with final donor creatinine greater than 6 mg/dL were selected. Results: four patients were selected, of whom all donors were in severe acute kidney injury (AKI). These donors presented rhabdomyolysis as a probable cause of severe AKI, were young, with no comorbidities and had decreased urinary volume in the last 24 hours. The clinical evolution of all the recipients was satisfactory, with a glomerular filtration rate after transplantation ranging from 48 to 98 mL/min/1.73 m2. Conclusion: this series of cases shows the possibility of using renal donors in severe AKI, provided the following are respected: donor age, rhabdomyolysis as the cause of AKI, and implantation-favorable biopsy findings. Additional studies with better designs, larger numbers of patients and longer follow-up times are needed.

RESUMO Introdução: O número de pacientes incidentes e prevalentes em diálise tem aumentado, assim como o número de candidatos ao transplante renal no Brasil, sem um aumento proporcional do número de doadores de órgãos. O uso de rins expandidos, quanto à função renal, pode ser uma alternativa para aumentar a oferta de órgãos. Objetivo: discutir a viabilidade do uso de rins expandidos quanto à função renal, que estejam em lesão renal aguda severa. Métodos: foram avaliados todos os casos de transplante renal de doador falecido realizados no Hospital das Clínicas de Botucatu da UNESP, de janeiro de 2010 a junho de 2018, totalizando 732 casos. Selecionou-se os casos com creatinina final do doador maior do que 6 mg/dL. Resultados: quatro pacientes foram selecionados, dos quais todos os doadores estavam em lesão renal aguda (LRA) severa. Esses doadores apresentavam rabdomiólise como provável causa de LRA severa, eram jovens, sem comorbidades e apresentavam diminuição de volume urinário nas últimas 24 horas. A evolução clínica de todos os receptores foi satisfatória, com taxa de filtração glomerular após o transplante variando entre 48 a 98 mL/min/1,73m2. Conclusão: essa série de casos mostra a possibilidade de utilização de doadores renais em LRA severa, desde que respeitadas as condições seguintes: idade do doador, rabdomiólise como causa de LRA e achados de biópsia favoráveis à implantação. Estudos adicionais com melhores desenhos, maior número de pacientes e maiores tempos de seguimento são necessários.

Antioxidant effect of endothelin-1 receptor antagonist protects the rat kidney against chronic injury induced by hypertension and hyperglycemia / Efeito antioxidante de antagonista dos receptores de endotelina-1 protege ratos contra lesão renal crônica induzida por hipertensão e hiperglicemia

ABSTRACT Hypertension and Diabetes mellitus are the two main causes of chronic kidney disease that culminate in the final stage of kidney disease. Since these two risk factors are common and can overlap, new approaches to prevent or treat them are needed. Macitentan (MAC) is a new non-selective antagonist of the endothelin-1 (ET-1) receptor. This study aimed to evaluate the effect of chronic blockade of ET-1 receptor with MAC on the alteration of renal function observed in hypertensive and hyperglycemic animals. Genetically hypertensive rats were divided into control hypertensive (HT-CTL) group, hypertensive and hyperglycemic (HT+DIAB) group, and hypertensive and hyperglycemic group that received 25 mg/kg macitentan (HT-DIAB+MAC25) via gavage for 60 days. Kidney function and parameters associated with oxidative and nitrosative stress were evaluated. Immunohistochemistry for neutrophil gelatinase-associated lipocalin (NGAL), ET-1, and catalase in the renal cortex was performed. The HT+DIAB group showed a decrease in kidney function and an increase in NGAL expression in the renal cortex, as well as an increase in oxidative stress. MAC treatment was associated with attenuated ET-1 and NGAL production and increases in antioxidant defense (catalase expression) and nitric oxide production. In addition, MAC prevented an increase in oxidant injury (as measured by urinary hydroperoxide and lipid peroxidation), thus improving renal function. Our results suggest that the antioxidant effect of the ET-1 receptor antagonist MAC is involved in the improvement of kidney function observed in hypertensive and hyperglycemic rats.

RESUMO Hipertensão e Diabetes Mellitus figuram como as duas principais causas de doença renal crônica que culmina em doença renal terminal. Uma vez que os dois fatores de risco são comuns e podem se sobrepor, novas abordagens preventivas e terapêuticas se fazem necessárias. O macitentan (MAC) é um novo antagonista não-seletivo dos receptores da endotelina-1 (ET-1). O presente estudo teve como objetivo avaliar os efeitos do bloqueio crônico dos receptores da ET-1 com MAC sobre a alteração da função renal em animais hipertensos e hiperglicêmicos. Ratos geneticamente hipertensos foram divididos em grupos com animais hipertensos de controle (HT-CTL), hipertensos e hiperglicêmicos (HT+DIAB) e hipertensos e hiperglicêmicos tratados com 25 mg/kg de macitentan (HT-DIAB+MAC25) via gavagem por 60 dias. Foram avaliados função renal e parâmetros associados ao estresse oxidativo e nitrosativo. Exames de imunoistoquímica foram realizados para lipocalina associada à gelatinase neutrofílica (NGAL), ET-1 e catalase no córtex renal. O grupo HT+DIAB exibiu diminuição da função renal e aumento na expressão de NGAL no córtex renal, bem como estresse oxidativo aumentado. O tratamento com MAC foi associado a atenuação da produção de ET-1 e NGAL e maior ativação das defesas antioxidantes (expressão de catalase) e elevação da produção de óxido nítrico. Além disso, o MAC evitou exacerbação da lesão oxidante (medida por hidroperóxidos urinários e peroxidação lipídica), melhorando assim a função renal. Nossos resultados sugerem que o efeito antioxidante do antagonista dos receptores da ET-1 MAC esteja imbricado no aprimoramento da função renal observada em ratos hipertensos e hiperglicêmicos.