Estimated glomerular filtration rate in clinical practice: Consensus positioning of the Brazilian Society of Nephrology (SBN) and Brazilian Society of Clinical Pathology and Laboratory Medicine (SBPC/ML) / Estimativa da taxa de filtração glomerular na prática clínica: posicionamento consensual da Sociedade Brasileira de Nefrologia (SBN) e Sociedade Brasileira de Patologia Clínica e Medicina Laboratorial (SBPC/ML)

ABSTRACT Chronic kidney disease (CKD) represents one of today's main public health problems. Serum creatinine measurement and estimation of the glomerular filtration rate (GFR) are the main tools for evaluating renal function. There are several equations to estimate GFR, and CKD-EPI equation (Chronic Kidney Disease - Epidemiology) is the most recommended one. There are still some controversies regarding serum creatinine measurement and GFR estimation, since several factors can interfere in this process. An important recent change was the removal of the correction for race from the equations for estimating GFR, which overestimated kidney function, and consequently delayed the implementation of treatments such as dialysis and kidney transplantation. In this consensus document from the Brazilian Societies of Nephrology and Clinical Pathology and Laboratory Medicine, the main concepts related to the assessment of renal function are reviewed, as well as possible existing controversies and recommendations for estimating GFR in clinical practice.

RESUMO A doença renal crônica (DRC) representa um dos principais problemas de saúde pública da atualidade. A dosagem da creatinina sérica e a estimativa da taxa de filtração glomerular (TFG) são as principais ferramentas para avaliação da função renal. Para a estimativa da TFG, existem diversas equações, sendo a mais recomendada a CKD-EPI (Chronic Kidney Disease - Epidemiology). Existem ainda algumas controvérsias com relação à dosagem da creatinina sérica e da estimativa da TFG, uma vez que vários fatores podem interferir nesse processo. Uma importante mudança recente foi a retirada da correção por raça das equações para estimativa da TFG, que superestimavam a função renal, e consequentemente retardavam a implementação de tratamentos como diálise e transplante renal. Neste documento de consenso da Sociedade Brasileira de Nefrologia e Sociedade Brasileira de Patologia Clínica e Medicina Laboratorial são revisados os principais conceitos relacionados à avaliação da função renal, possíveis controvérsias existentes e recomendações para a estimativa da TFG na prática clínica.

Understanding of the role of serum creatinine in a subset of the Brazilian population / Conhecimento de uma amostragem da população brasileira sobre a função da creatinina sérica

Abstract Introduction: Chronic kidney disease is usually asymptomatic, and its diagnosis depends on laboratory tests, with emphasis on serum creatinine and proteinuria. Objective: To assess knowledge on the role of serum creatinine as a biomarker of kidney function in a sample of the Brazilian population. Method: Cross-sectional observational study conducted in São Paulo (SP, Brazil), in which a random adult population was interviewed. Results: A total of 1138 subjects were interviewed, with a median age of 36 years old (27-52); 55.1% were female. Regarding the "creatinine" biomarker, 40.6% stated they had never performed such a test. When asked about their knowledge on the usefulness of this exam, only 19.6% knew its function. The other responses were "I don't know" (71.6%), evaluating heart function (0.9%) and liver function (7.8%). Of those who reported they had already taken a creatinine test, only 29.4% correctly identified the role of creatinine. When dividing the groups into "knows" and "does not know" the function of creatinine, a statistically significant difference (p < 0.05) was observed regarding level of education, female sex, being a healthcare student/worker, having ever measured creatinine, knowing someone with kidney disease and older age. In the multivariate analysis, the main variable related to knowing the creatinine role was having previously taken the test (OR 5.16; 95% CI 3.16-8.43, p < 0.001). Conclusion: There is a significant lack of knowledge about creatinine and its use in checkups. The results indicate that greater efforts are needed from healthcare professionals to raise awareness on the role of serum creatinine.

Resumo Introdução: A doença renal crônica costuma ser assintomática e seu diagnóstico depende da realização de exames laboratoriais, com destaque para a creatinina sérica e pesquisa de proteinúria. Objetivo: Avaliar em uma amostra da população brasileira o conhecimento sobre o papel da creatinina sérica como marcador de função renal. Método: Estudo observacional transversal realizado na cidade de São Paulo (SP, Brasil), em que foi entrevistada uma população adulta aleatória. Resultados: Foram entrevistados 1138 indivíduos, com idade mediana de 36 anos (27-52); 55,1% do sexo feminino. Com relação ao marcador "creatinina", 40,6% afirmaram que nunca realizaram tal dosagem. Quando questionados quanto ao conhecimento sobre a utilidade desse exame, somente 19,6% sabiam a sua função. As outras respostas foram "não sei" (71,6%), avaliar o funcionamento do coração (0,9%) e fígado (7,8%). Dos que afirmaram já terem realizado o exame de creatinina, somente 29,4% acertaram a função da creatinina. Ao dividir os grupos em "sabe" e "não sabe" a função da creatinina, percebeu-se diferença estatisticamente significante (p < 0,05) em relação ao grau de escolaridade, sexo feminino, ser aluno/trabalhador da saúde, ter dosado creatinina alguma vez, conhecer alguém com doença renal e maior idade. Na análise multivariada, a principal variável relacionada com conhecer a função da creatinina foi ter realizado o exame anteriormente (OR 5,16; IC 95% 3,16-8,43, p < 0,001). Conclusão: Há grande desconhecimento sobre a creatinina e seu uso em check-ups. Os resultados indicam que é necessário maior esforço por parte dos profissionais de saúde para divulgar o papel da creatinina sérica.

Experiencia de un programa de estandarización de creatinina en una región de ingresos bajos de Latinoamérica / Experience of a creatinine standardisation programme in a low-income region of Latin America / Experiência de um programa de padronização de creatinina em uma região de baixa renda da América Latina

Resumen Los programas de estandarización de creatinina mantienen su vigencia. El objetivo es describir la experiencia adquirida durante el desarrollo de un programa de estandarización de creatinina en una provincia de bajos recursos y mostrar los aspectos que se deben considerar para su escalabilidad en un contexto semejante. El programa se desarrolló en etapas: en la primera (2010) se realizó el relevamiento de 49 laboratorios clínicos (LC) distribuidos en toda la provincia del Chaco, Argentina. En la segunda (2012) se ajustó el error aleatorio (EA) aplicando protocolos internacionales (CLSI EP-5A). En la tercera etapa (2014-2015) se procesaron paneles de sueros con concentraciones asignadas por un método trazable al de referencia y al estándar internacional (CG-IDMS). Se aplicaron protocolos internacionales para evaluar el error total (ET) de la determinación en cada laboratorio (CLSI EP-10A). En 2016, aplicando herramientas de calidad, se evaluaron las barreras en el proceso. Se observó en el EA: para un nivel de 1,00 mg/dL, ningún LC alcanzó los niveles deseables; para un nivel de 2,5 mg/dL solo 9 (23%) los alcanzaron. Concluida la segunda y tercera etapa, solo 18 laboratorios (48,7%) lograron ajustar el EA y/o ET, pero resultó dificultoso sostenerlo en el tiempo. Los reactivos, calibradores y controles son producidos por la industria y depende del estado el control de los mismos. La homogeneidad del equipamiento depende de la accesibilidad económica y del volumen de trabajo. El medio ambiente, la temperatura y la calidad del agua siguen siendo una dificultad para la escalabilidad.

Abstract Creatinine standardisation programmes remain valid. The objective of this work is to describe the experience acquired during the development of a creatinine standardisation programme in a low-resource province and show the aspects that should be considered for its scalability in a similar context. The programme was developed in stages. The first one was carried out in 2010. It consists of a structured survey completed by 49 clinical laboratories (CL) distributed throughout the province. In the second stage (2012) the random error (RE) was adjusted by applying international protocols (CLSI EP-5A). In the third stage (2014-2015), panels of sera were processed with concentrations assigned by a method traceable to the reference and the international standard (CG-IDMS). International protocols were applied to evaluate the total error (TE) of the determination in each laboratory (CLSI EP-10A). In 2016, applying quality tools, the barriers in the process were evaluated. In the RE, it was observed: for a level of 1.00 mg/dL, no CL reached the desirable levels; for a level of 2.5 mg/dL only 9 (23%) CL achieved them. Once the second and third stages were completed, only 18 laboratories (48.7%) managed to adjust the RE and/or TE, but it was difficult to sustain it over time. With respect to materials, reagents, calibrators, and controls, they are produced by the industry depending on the state of their control. The homogeneity of the equipment depends on economic accessibility and volume of work. The environment, temperature, and water quality are a barrier to scalability.

Resumo Os programas de padronização da creatinina permanecem válidos. O objetivo é descrever a experiência adquirida durante o desenvolvimento de um programa de padronização de creatinina em uma província com poucos recursos e mostrar os aspectos que devem ser levados em consideração para sua escalabilidade em um contexto semelhante. O programa foi desenvolvido em etapas: Na primeira (2010), foi realizado um levantamento de 49 laboratórios clínicos (LC) distribuídos em toda a provincia do Chaco, na Argentina. Na segunda etapa (2012) o erro aleatório (EA) foi ajustado através da aplicação de protocolos internacionais (CLSI EP-5A). Na terceira etapa (2014-2015), foram processados paineis de soros com concentrações atribuídas por método rastreável à referência e ao padrão internacional (CG-IDMS). Protocolos internacionais foram aplicados para avaliar o erro total (ET) da determinação em cada laboratório (CLSI EP-10A). Em 2016, aplicando ferramentas de qualidade, foram avaliadas as barreiras no processo. Observou-se na EA: para o nível de 1,00 mg/dL nenhuma LC atingiu os níveis desejáveis; para um nível de 2,5 mg/dL, apenas 9 (23%) os atingiram. Concluídas a segunda e terceira etapas, apenas 18 laboratórios (48,7%) conseguiram ajustar o EA e/ou o ET, mas foi difícil sustentá-lo ao longo do tempo. No que diz respeito aos reagentes, calibradores e controles, eles são produzidos pela indústria. dependendo do estado o seu controle. A homogeneidade do equipamento depende da acessibilidade econômica e do volume de trabalho. O meio ambiente, a temperatura e a qualidade da água continuam sendo uma dificuldade para a escalabilidade.

Renal deficit and associated factors in children born with low birth weight / Déficit renal e fatores associados em crianças nascidas com baixo peso

ABSTRACT Introduction: Kidney problems may be due to low birth weight alone or may occur in association with other conditions. The objective this study was to evaluate the association between maternal and birth characteristics, anthropometric measurements, and kidney function deficit in low birth weight infants. Methods: Cross-sectional study with children who were born weighing < 2500 grams and were under outpatient follow-up. Maternal factors investigated were prenatal care and presence of hypertension, diabetes, and infection during pregnancy. The children's variables were sex, gestational age, birth weight, Apgar score, use of nephrotoxic medications, age, body weight at the time of evaluation, height, and serum creatinine and cystatin C dosages. The glomerular filtration rate (GFR) was estimated with the combined Zapittelli equation. Multivariate logistic regression model was used for identification of associated factors, with renal function deficit (GFR < 60 mL/min/1.73 m2) as the dependent variable. Results: Of the 154 children evaluated, 34.42% had kidney function deficit. Most of them had a gestational age > 32 weeks (56.6%), a mean birth weight of 1439.7 grams, and mean estimated GFR of 46.9 ± 9.3 mL/min/1.73 m2. There was a significant association of GFR < 60 mL/min/1.73 m2 with children's current weight and use of nephrotoxic drugs. Discussion: Children born with low birth weight had a high prevalence of kidney function deficit and current normal weight was a protective factor while the use of nephrotoxic drugs during perinatal period increased the chance of kidney deficit. These findings reinforce the need to evaluate the kidney function in these children, especially those who use nephrotoxic drugs.

RESUMO Introdução: Problemas renais podem ser devido apenas ao baixo peso ao nascer ou podem ocorrer em associação com outras condições. O objetivo deste estudo foi avaliar a associação entre características maternas e de nascimento, medidas antropométricas e déficit da função renal em bebês de baixo peso ao nascer. Métodos: Estudo transversal com crianças que nasceram com peso < 2500 gramas e estavam sob acompanhamento ambulatorial. Os fatores maternos investigados foram cuidados pré-natal e presença de hipertensão, diabetes e infecção durante a gravidez. As variáveis das crianças foram sexo, idade gestacional, peso ao nascer, índice Apgar, uso de medicamentos nefrotóxicos, idade, peso corporal no momento da avaliação, altura e dosagens séricas de creatinina e cistatina C. A taxa de filtração glomerular (TFG) foi estimada com a equação combinada de Zapittelli. Utilizou-se um modelo de regressão logística multivariada para identificação de fatores associados, com déficit da função renal (TFG < 60 mL/min/1,73 m2) como variável dependente. Resultados: Das 154 crianças avaliadas, 34,42% apresentaram déficit da função renal. A maioria tinha idade gestacional > 32 semanas (56,6%), peso médio ao nascer de 1439,7 gramas, e TFG média estimada de 46,9 ± 9,3 mL/min/1,73 m2. Houve uma associação significativa da TFG < 60 mL/min/1,73 m2 com o peso atual das crianças e o uso de medicamentos nefrotóxicos. Discussão: Crianças nascidas com baixo peso apresentaram alta prevalência de déficit da função renal e o peso atual normal foi um fator de proteção, enquanto o uso de medicamentos nefrotóxicos durante o período perinatal aumentou a chance de déficit renal. Estes achados reforçam a necessidade de avaliar a função renal destas crianças, especialmente aquelas que usam medicamentos nefrotóxicos.

Value of serum creatinine-to-cystatin C ratio in assessing the prognosis of hepatitis B virus-related acute-on-chronic liver failure / 临床肝胆病杂志

ObjectiveTo investigate the clinical value of serum creatinine-to-cystatin C ratio （CCR） in evaluating the prognosis of hepatitis B virus-related acute-on-chronic liver failure （HBV-ACLF）. MethodsA retrospective analysis was performed for the clinical data of 130 patients with HBV-ACLF （treatment group） who were hospitalized in Department of Infectious Diseases， The First Affiliated Hospital of Soochow University， from January 2021 to November 2022. According to the treatment outcome， they were divided into survival group with 87 patients and death group with 43 patients； according to the presence or absence of infection， they were divided into infection group with 37 patients and non-infection group with 93 patients. A total of 30 individuals who underwent physical examination during the same period of time were enrolled as control group. Routine blood test results were collected on the day of admission， including white blood cell count， platelet count， neutrophil count， and lymphocyte count； serum creatinine， cystatin C， serum albumin （Alb）， and prothrombin time （PT） were observed on the day of admission and on days 5， 10， and 15 of hospitalization， and related indicators were calculated， including CCR， neutrophil-to-lymphocyte ratio （NLR）， platelet-to-lymphocyte ratio （PLR）， prognostic nutritional index （PNI）， CCR5 （CCR on day 5 after admission）， ΔCCR5 （CCR on day 5 after admission minus CCR on the day of admission）， CCR10 （CCR on day 10 after admission）， ΔCCR10 （CCR on day 10 after admission minus CCR on day 5 after admission）， CCR15 （CCR on day 15 after admission）， and ΔCCR15 （CCR on day 15 after admission minus CCR on day 10 after admission）. The above indicators were compared between the survival group and the death group and between the infection group and the non-infection group. The Mann-Whitney U test was used for comparison of continuous data between two groups， and the Kruskal-Wallis H test was used for comparison between multiple groups. The univariate and multivariate logistic regression analyses were used to investigate the influencing factors for disease prognosis； the receiver operating characteristic （ROC） curve was used to assess the value of CCR in predicting HBV-ACLF death events， and the DeLong test was used for comparison of the area under the ROC curve （AUC）. ResultsThere were significant differences in CCR， NLR， PNI， PT， and Alb at baseline between the treatment group and the healthy control group （all P<0.001）， and there were significant differences in CCR， NLR， and PT between the survival group and the death group on the day of admission （all P<0.05）. Among the 130 patients with HBV-ACLF， there were 25 in the precancerous stage， 48 in the early stage， 32 in the intermediate stage， and 25 in the advanced stage， and there were significant differences in baseline CCR， PLR， and PT between the patients in different stages of HBV-ACLF （all P<0.05）. There were significant differences in ΔCCR5 and NLR between the infection group and the non-infection group （P<0.05）， and there were significant differences in ΔCCR5， CCR10， and CCR15 between the survival group and the death group （all P<0.05）. The multivariate logistic regression analysis showed that ΔCCR5 （odds ratio ［OR］=1.175， 95% confidence interval ［CI］： 1.098‍ — ‍1.256， P<0.001）， NLR （OR=0.921， 95%CI： 0.880‍ — ‍0.964， P<0.001）， and PT （OR=0.921， 95%CI： 0.873‍ — ‍0.973， P=0.003） were independent influencing factors for the prognosis of HBV-ACLF patients. ΔCCR5 had an AUC of 0.774， a sensitivity of 0.687， and a specificity of 0.757， and the AUC of ΔCCR5+PT+NLR was 0.824， which was significantly higher than the AUC of ΔCCR5， NLR， or PT alone （all P<0.05）. ConclusionΔCCR5， NLR， and PT can reflect the condition and prognosis of patients with HBV-ACLF and are independent predictive indicators for death events in patients with HBV-ACLF. The combination ofΔCCR5， PT， and NLR has the best predictive efficiency.

A spurious elevation of serum creatinine level in a patient with Crohn's disease without histologic kidney damage: a case report and review of the literature / Elevação espúria do nível de creatinina sérica em ­paciente com doença de Crohn sem lesão renal histológica: relato de caso e revisão da literatura

ABSTRACT Patients with inflammatory bowel disease (IBD) are prone to develop kidney injury. Renal involvement in IBD patients is usually diagnosed by the measurement of serum creatinine and the estimation of the glomerular filtration rate. We describe a patient with IBD who presented with large fluctuations in his serum creatinine level (~3.0-fold) without significant histologic abnormalities and with a normal cystatin C level. This appears to be related to a high-protein diet and intermittent fasting. Even though the impact of a high-protein diet on mild elevations of the serum creatinine level has been described, large fluctuations in serum creatinine from diet alone, as seen in this case, have never been reported, raising the question about the potential contribution of inflamed bowel on gut absorption or metabolism of creatinine. This case highlights the importance of a detailed history, including the dietary habits, when encountering a patient with increased serum creatinine level, and careful interpretation of serum creatinine in a patient with a creatinine high-protein diet or underlying IBD.

RESUMO Pacientes com doença inflamatória intestinal (DII) são propensos a desenvolver lesão renal. O envolvimento renal em pacientes com DII é geralmente diagnosticado pela medição da creatinina sérica e pela estimativa da taxa de filtração glomerular. Descrevemos um paciente com DII que apresentou grandes flutuações em seu nível de creatinina sérica (~3,0 vezes) sem anormalidades histológicas significativas e com nível normal de cistatina C. Isso parece estar relacionado a uma dieta rica em proteínas e jejum intermitente. Ainda que o impacto de uma dieta rica em proteínas em elevações leves do nível de creatinina sérica tenha sido descrito, nunca foram relatadas grandes flutuações na creatinina sérica apenas devido à dieta, como observado neste caso, o que levanta a questão sobre a possível contribuição do intestino inflamado na absorção intestinal ou no metabolismo da creatinina. Esse caso destaca a importância de um histórico detalhado, incluindo os hábitos alimentares, ao se deparar com um paciente com nível de creatinina sérica aumentado, e a interpretação cuidadosa da creatinina sérica em um paciente com dieta rica em proteínas ou DII subjacente.

Caracterización clínica de la Nefropatía por Poliomavirus BK en pacientes trasplantados renales / Clinical characterization of Polyomavirus BK nephropathy in kidney transplanted patients

INTRODUCCIÓN. La nefropatía por poliomavirus BK resulta un problema emergente en el trasplante renal, pues contribuye a la pérdida temprana de los injertos renales. OBJETIVO. Caracterizar clínicamente a los pacientes trasplantados renales con nefropatía por poliomavirus BK. MATERIALES Y MÉTODOS. Estudio observacional, descriptivo, realizado en el Hospital de Especialidades Carlos Andrade Marín en el período 2013-2022, se obtuvo una base de datos anonimizada, 479 pacientes trasplantados renales, de estos se identificaron 37 pacientes que corresponde a un 7,7% con nefropatía por poliomavirus BK, se realizó un análisis con el programa estadístico SPSS v26®. RESULTADOS. La población estuvo caracterizada por pacientes del sexo masculino (56,8%), con una edad media de 48,2 años, el donante cadavérico fue el más frecuente (94,5%), la mayor parte del tratamiento de la nefropatía por poliomavirus BK consistió en cambio de micofenolato sódico a everolimus y se mantuvo con 50% de Tacrolimus y Prednisona (40,5%); al valorar el cambio de los valores de creatinina, los niveles más elevados fueros a los 12 meses cuando la pérdida renal fue temprana (p: 0,042), y de la misma manera a los 12 meses, fueron más elevados los niveles de creatinina cuando el diagnóstico histopatológico fue Nefropatía por Poliomavirus Clase 3 (p: 0,01). DISCUSIÓN. La prevalencia de la nefropatía se mantuvo por debajo del 10% reportado a nivel global, la creatinina empeoró en pacientes con pérdida temprana del injerto renal y con una clase patológica avanzada, hecho reportado en la fisiopatología de la enfermedad. CONCLUSIÓN. La pérdida del injerto renal temprano presentó una creatinina más alta que la tardía. Es recomendable un tamizaje adecuado para la detección temprana del virus BK siendo crucial para prevenir el deterioro de la función renal y limitar la posterior pérdida del injerto.

INTRODUCTION: BK polyomavirus nephropathy is emerging as a significant concern in kidney transplantation, as it contributes to the early loss of renal grafts. OBJECTIVE: The aim of this study was to clinically characterize renal transplant recipients with BK polyomavirus nephropathy. MATERIALS AND METHODS: An observational and descriptive study was conducted at Carlos Andrade Marín Specialties Hospital during the period of 2013 to 2022. An anonymized database comprising 479 renal transplant patients was utilized. Among these, 37 patients, constituting 7.7%, were identified with BK polyomavirus nephropathy. Data analysis was performed using the statistical program SPSS v26®. RESULTS: The study population was predominantly composed of male patients (56.8%) with a mean age of 48.2 years. Deceased donors accounted for the majority (94.5%) of cases. The primary approach for managing BK polyomavirus nephropathy involved transitioning from mycophenolate sodium to everolimus, alongside maintaining a regimen of 50% tacrolimus and 40.5% prednisone. When assessing changes in creatinine values, the highest levels were observed at 12 months, coinciding with early renal loss (p: 0.042). Similarly, at the 12-month mark, elevated creatinine levels were associated with a histopathological diagnosis of Polyomavirus nephropathy Class 3 (p: 0.01). DISCUSSION: The prevalence of nephropathy remained below the globally reported threshold of 10%. Creatinine levels worsened in patients experiencing early graft loss and an advanced pathological classification, aligning with established disease pathophysiology. CONCLUSION: Early renal graft loss was associated with higher creatinine levels compared to delayed loss. Adequate screening for early detection of BK virus is recommended, as it plays a crucial role in preventing renal function deterioration and limiting subsequent graft loss.

Comparison of GFR measurement with a two-blood sample technique using [99mTc]Tc-DTPA vs. creatinine-based equations in potential kidney donors / Comparação da medição da TFG com uma técnica com duas amostras de sangue usando [99mTc]Tc-DTPA vs. equações baseadas em creatinina em potenciais doadores de rim

ABSTRACT Introduction: Accurate determination of glomerular filtration rate (GFR) is crucial for selection of kidney donors. Nuclear medicine methods are considered accurate in measuring GFR but are not always easily available. The four-variable Modification of Diet in Renal Disease (MDRD4), Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI), and Full Age Spectrum (FAS) formulas are common equations for estimating GFR and are recommended for initial assessment of kidney donors. The aim of this study was to evaluate the performance of these GFR estimation equations compared with technetium-99m diethylenetriaminepentaacetic acid ([99mTc]Tc-DTPA) clearance. Methods: We compared GFR estimation by [99mTc]Tc-DTPA clearance using a two-blood sample method with estimation by MDRD4, CKD-EPI, and FAS creatinine-based equations in a population of healthy potential kidney donors. Results: A total of 195 potential kidney donors (68.2% female; mean age 49 years, range 21-75 years) were included in this study. Mean [99mTc]Tc-DTPA measured GFR (mGFR) was 101.5 ± 19.1 mL/min/1.73 m2. All three equations underestimated the GFR value measured by [99mTc]Tc-DTPA (MDRD4: -11.5 ± 18.8 mL/min/1.73 m2; CKD-EPI: -5.0 ± 17.4 mL/min/1.73 m2; FAS: -8.3 ± 17.4 mL/min/1.73 m2). Accuracy within 30% and 10% of the measured GFR value was highest for CKD-EPI. Conclusion: The CKD-EPI equation showed better performance in estimating GFR in healthy potential kidney donors, proving to be a more accurate tool in the initial assessment of kidney donors. However, creatinine-based equations tended to underestimate kidney function. Therefore, GFR should be confirmed by another method in potential kidney donors.

RESUMO Introdução: Determinar precisamente a taxa de filtração glomerular (TFG) é crucial para seleção de doadores de rim. Métodos de medicina nuclear são considerados precisos na medição da TFG, mas nem sempre estão facilmente disponíveis. As fórmulas Modification of Diet in Renal Disease de 4 variáveis (MDRD4), Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI), e Full Age Spectrum (FAS) são equações comuns para estimar a TFG, sendo recomendadas para avaliação inicial dos doadores. Este estudo visou avaliar o desempenho destas equações de estimativa da TFG em comparação com o clearance do tecnécio-99m-ácido dietilenotriaminopentacético ([99mTc]Tc-DTPA). Métodos: Comparamos a TFG por clearance de [99mTc]Tc-DTPA usando um método com duas amostras de sangue com estimativa da TFG pelas equações MDRD4, CKD-EPI e FAS baseadas em creatinina em uma população de potenciais doadores saudáveis. Resultados: Incluiu-se 195 potenciais doadores de rim (68,2% mulheres; idade média de 49 anos, intervalo 21-75 anos). A TFG média medida por [99mTc]Tc-DTPA foi 101,5 ± 19,1 mL/min/1,73m2. As três equações subestimaram o valor da TFG medida por [99mTc]Tc-DTPA (MDRD4: -11,5 ± 18,8 mL/min/1,73 m2; CKD-EPI: -5,0 ± 17,4 mL/min/1,73 m2; FAS: -8,3 ± 17,4 mL/min/1,73 m2). A precisão dentro de 30% e 10% do valor da TFG medida foi maior para CKD-EPI. Conclusão: A equação CKD-EPI mostrou melhor desempenho na estimativa da TFG em potenciais doadores de rim saudáveis, revelando-se uma ferramenta mais precisa na avaliação inicial dos doadores. Entretanto, equações baseadas em creatinina tendem a subestimar a função renal. Portanto, a TFG deve ser confirmada por outro método em potenciais doadores.

Effect of Hayani Date (Phoenix dactylifera L) Peels on Blood Sugar, Blood Lipids, Liver and Kidney Functions, and Inflammation in Diabetic Rats

This study aimed to investigate the effect of Hayani date peel powder and its methanolic extract on glycemia and lipidemia in streptozotocin-induced diabetic rats as well as their effects on kidney and liver functions in addition to their anti-inflammatory activity. Twenty-four rats were used in this study, six of them served as normal control (group 1) which continued feeding on the basal diet, while the remaining 18 rats were injected with streptozotocin (50mg/kg) to induce diabetes. The diabetic rats were divided into three groups (6 rats each), one of them feeding on the basal diet only which acted as diabetic control (group 2), another group fed on the basal diet and treated orally with the peel extract in a concentration of 250 mg/kg body weight (group 3), while the third group was treated with peel powder merged in the basal diet with a concentration of 5% w/w (group 4). The results showed that the extract and the powder of the peels significantly decreased the blood glucose, glycated hemoglobin (HbAlc), total cholesterol (TC), total triglycerides (TG), low density lipoprotein cholesterol (LDL-c), very low density lipoprotein cholesterol (VLDL-c), alanine transaminase (ALT), aspartate transaminase (AST), creatinine, and uric acid as well as cyclooxygenase-2 (COX-2), prostaglandin 2 (PGE2), tumor necrosis factor alpha (TNF-?), interleukin 1B (IL-1?), and inducible nitric oxide synthase (iNOS) levels. In contrast, significant increases in serum insulin, high density lipoprotein cholesterol (HDL-c), and albumin were noticed in comparison to diabetic control. Generally, the peel extract was more effective than the peel powder. It is recommended by eating the whole fruit of date without peeling.

Assessment of serum magnesium and correlation with glycemic control and complication in type 2 diabetes mellitus – A cross-sectional study in a tertiary care hospital in eastern zone of India

Background: Diabetes mellitus (DM) is an expanding global health problem. Type 2 DM (T2DM) patients account about 90% of total DM patients. Magnesium is important for different physiological mechanism. Hypomagnesemia is common in T2DM patient. Magnitude of hypomagnesemia is related with glycemic control and is associated with complications of T2DM. Aims and Objectives: Our aim of the study was to assess the prevalence of hypomagnesemia in patients of T2DM patients and to find their correlation with glycemic control and complications of T2DM patients in rural population of eastern zone of India. Materials and Methods: The hospital-based cross-sectional study includes 99 male and female DM patients between 15 and 60 years age. Fasting blood sugar, postprandial blood sugar, HbA1c, serum total magnesium, and urine albumin creatinine ratio were measured. Data were entered into Microsoft Excel spreadsheet and then analyzed by SPSS (version 25.0; SPSS Inc.) and GraphPad Prism (version 5.0). P < 0.05 was considered statistically significant. Results: From our study, we observed that hypomagnesemia is common in T2DM patients. The magnitude of hypomagnesemia is correlated with glycemic control (P < 0.0001). Moreover, hypomagnesemia is associated with diabetic kidney diseases (P < 0.05). Conclusion: It can be concluded that serum magnesium should be monitored in all T2DM patients and should be managed appropriately because hypomagnesemia may induce complications in T2DM patients.

Primeras recomendaciones de consenso SLANH - COLABIOCLI / Primeiras Recomendações de Consenso SLANH - COLABIOCLI / (Sociedad Latinoamericana de Nefrología e Hipertensión - Confederación Latinoamericana de Bioquímica Clínica) / Informe de la tasa de filtración glomerular estimada junto a la determinación de la creatininemia en población adulta / First SLANH-COLABIOCLI Consensus Recommendations

Resumen La enfermedad renal crónica (ERC) es de alta prevalencia en América Latina y en todo el mundo. Se estima que entre 10 y 20% de la población adulta es portadora de ERC y su prevalencia va en aumento. La ERC progresa en forma silenciosa. Su diagnóstico temprano y oportuno permite iniciar un tratamiento efectivo, en la mayoría de los casos, para detener la enfermedad. Desde hace mucho tiempo, el análisis de la creatininemia es la principal prueba utilizada para valorar la función renal, pero su confiabilidad es limitada. De acuerdo con las recomendaciones de las GUIAS KDOQI del año 2002 la tasa de filtración glomerular estimada (TFGe) obtenida a través de fórmulas, se estableció como una de las herramientas principales para detectar la enfermedad renal de manera precoz, ya que alerta de forma precisa al médico y al equipo de salud sobre el nivel de función renal del paciente. La detección de una TFGe disminuida (menor de 60 mL/min/1,73 m2) es clínicamente relevante, ya que permite establecer el diagnóstico de enfermedad renal en adultos. En el año 2022, en una encuesta realizada por SLANH y COLABIOCLI dirigida a los laboratorios de análisis clínicos de América Latina (n: 237), el 49% de los mismos no informaban la TFGe rutinariamente. En base a esta realidad SLANH y COLABIOCLI elaboraron estas recomendaciones de consenso en referencia al uso de la TFGe.

Abstract Chronic kidney disease (CKD) has a high prevalence worldwide and in Latin America (10 to 20% of the adult population) and is increasing. CKD progresses silently. Opportune diagnosis and treatment are effective in most cases to improve outcomes. Serum creatinine was the main test to assess kidney function, but its reliability is limited. Through the KDOQI Guidelines 2002, the estimated glomerular filtration rate (eGFR) obtained from equations was established as one of the main tools for the early detection of kidney disease in clinical practice. The detection of a decreased eGFR (less than 60 mL/min/1.73 m2) is clinically relevant. This cut-off level establishes the diagnosis of kidney disease in adults. In 2022 SLANH and COLABIOCLI conducted a survey among the clinical laboratories from Latin America. The survey included 237 laboratories, 49% of which did not routinely report the eGFR. Based on this situation, SLANH and COLABIOCLI have elaborated the following consensus recommendations regarding the use of eGFR.

Resumo A doença renal crônica (DRC) é altamente prevalente na América Latina e em todo o mundo. Estima-se que entre 10 e 20% da população adulta seja portadora de DRC e sua prevalência esteja aumentando. A DRC progride silenciosamente. Seu diagnóstico precoce e oportuno permite iniciar um tratamento eficaz, na maioria dos casos, para estancar a doença. Faz muito tempo, a análise da creatinina tem sido o principal teste usado para avaliar a função renal mas sua confiabilidade é limitada. De acordo com as recomendações dos GUIAS KDOQI do ano de 2002, a estimativa da taxa de filtração glomerular (eGFR), obtida por meio de fórmulas, consolidou-se como uma das principais ferramentas para a detecção precoce da doença renal, visto que alerta com precisão ao médico e ao equipe de saúde sobre o nível de função renal do paciente. A detecção de uma eGFR diminuída (inferior a 60 mL/min/1,73 m2) é clinicamente relevante, pois permite estabelecer o diagnóstico de doença renal em adultos. No ano de 2022, em pesquisa realizada pela SLANH e COLABIOCLI dirigida a laboratórios de análises clínicas da América Latina (n: 237), 49% deles não relataram rotineiramente eGFR. Com base nessa realidade, SLANH e COLABIOCLI prepararam essas recomendações de consenso sobre o uso de eGFR.

Self-Measured Blood Pressure and Target Organ Damage in Newly Detected Hypertension in South Gujarat, India

Introduction: Blood pressure transient spikes have been considered to be noise and only a hindrance to a proper assessment of typical blood pressure, which is defined as the actual underlying average blood pres-sure over a long period of time. The current study aimed to see if the highest Self measured Systolic blood Pressure could be utilized to forecast the occurrence of Target organ damage and evaluate the independent association between the maximum Self measured Systolic blood Pressure and Target organ damage in indi-viduals with untreated hypertension. Method: We evaluated the urine albumin/creatinine ratio (UACR) and carotid intima-media thickness (IMT) using ultrasonography in 462 hypertensive individuals who had never taken treatment for their hypertension. Residential blood pressure was recorded. Result: The maximal Self measured Systolic blood Pressure had considerably higher association coefficients with left ventricular mass index (LVMI) and carotid intima-media thickness than the mean Self measured Sys-tolic blood Pressure. Irrespective of the mean Self measured Blood pressure level, multivariate regression studies showed that the maximal Self measured Systolic blood Pressure was independently related with left ventricular mass index and carotid intima-media thickness. Conclusion: Transiently high blood pressure measurements recorded at Self measured shouldn't be dis-missed as noise but rather taken seriously as significant warning signs of hypertensive Target organ damage in the heart and arteries.

Correlation of serum creatinine, blood urea nitrogen and uric acid levels in patients with nephrotic syndrome / 公共卫生与预防医学

Objective To explore the correlation between serum creatinine, blood urea nitrogen content and uric acid level in adult nephrotie syndrome (AS) patients of different ages, in order to provide a theoretical basis for the prevention and control of uric acid metabolism. Methods Individuals of different ages who were diagnosed with nephrotic syndrome from March 2018 to August 2020 in the outpatient department of our hospital were selected as research subjects by stratified random sampling,healthy individuals who underwent physical examination during the same period were selected as controls .The age range of the subjects was 18-55 years old. The biochemical test results of serum creatinine, blood urea nitrogen and uric acid were retrospectively collected from patients of different ages. Pearson correlation analysis of adult serum creatinine, blood urea nitrogen and uric acid levels. Results The levels of creatinine and blood urea nitrogen in healthy adults showed an upward trend at the age of 18-40, and reached a plateau at the age of 40; while the level of uric acid showed an upward trend with age. The levels of serum creatinine, blood urea nitrogen and uric acid in AS patients at different ages were higher than those in healthy controls, and the increase was most pronounced between the ages of 45 and 55. The t-test results showed that the serum creatinine, blood urea nitrogen and uric acid contents of healthy controls were different from those of AS patients except for the 18-22 age group. The main performance was that AS patients had higher measured values than healthy controls. Pearson correlation was used to analyze the correlation between serum creatinine and blood urea nitrogen levels and uric acid in AS patients of different ages. The results showed that the 41-45-year-old patients had the strongest correlation with uric acid, r was 0.584; The patients' blood urea nitrogen level had the strongest correlation with uric acid, with r of 0.373. The age groups with the correlation between serum creatinine, blood urea nitrogen and uric acid content in AS patients were stratified according to gender. There was a significant positive correlation (r>0.45, P0.30, P<0.05). Conclusion The expression level of serum creatinine in 34-45 years old patients with nephrotic syndrome can effectively predict the level of uric acid, and the predictive value of women is higher than that of men.

Risk factors and predictive analysis of hyperkalemia after heart transplantation / 器官移植

Objective To analyze clinical prognosis, risk factors and predictive indexes of hyperkalemia in recipients after heart transplantation. Methods Clinical data of 158 recipients were retrospectively analyzed. According to the serum potassium levels within postoperative 1-year follow-up, all recipients were divided into the normal serum potassium level group (n=83), hyperkalemia group (n=43) and severe hyperkalemia group (n=32). The incidence and prognosis of hyperkalemia after heart transplantation were summarized. The risk factors and predictive indexes of hyperkalemia after heart transplantation were identified. Results The incidence of hyperkalemia and severe hyperkalemia within postoperative 1 year was 47.5%(75/158) and 20.3%(32/158), respectively. In the severe hyperkalemia group, the fatality was 16%(5/32), higher than 8%(7/83) in the normal serum potassium level group and 7%(3/43) in the hyperkalemia group. The mean serum creatinine (Scr) within 6 months before heart transplantation, the final total bilirubin level before heart transplantation, postoperative hemodialysis time, the Scr level and N-terminal pro-brain natriuretic peptide level at postoperative 1 d were the independent risk factors for hyperkalemia following heart transplantation (all P < 0.05). The mean Scr level within 6 months before heart transplantation, postoperative hemodialysis time, and Scr levels at postoperative 1 and 7 d could be used to predict postoperative severe hyperkalemia. Conclusions The recipients with severe hyperkalemia after heart transplantation obtain poor prognosis. The mean Scr level within 6 months before heart transplantation, the final total bilirubin level before heart transplantation, postoperative hemodialysis time, and the Scr level and N-terminal pro-brain natriuretic peptide level at postoperative 1 d are the independent risk factors for hyperkalemia after heart transplantation. Perioperative Scr level and postoperative hemodialysis time may be used to predict the incidence of severe hyperkalemia within 1 year after heart transplantation.

A retrospective study and value analysis of erythropoietin in improving postoperative anemia in renal transplant patients / 现代泌尿外科杂志

【Objective】 To explore the effects of early application of erythropoietin (EPO) in patients with anemia after renal transplantation. 【Methods】 Patients who underwent renal transplantation in the First Affiliated Hospital of Soochow University were retrospectively analyzed. According to whether EPO was applied after operation, the patients were divided into EPO group and routine group. Patients with delayed renal function recovery were excluded, and the remaining patients were further analyzed. The general, laboratory and follow-up data of the two groups were compared, and adverse drug reactions were observed. 【Results】 The hemoglobin (P=0.026), red blood cell count (P=0.038) and hematocrit (P=0.011) in EPO group were higher than those in the routine group 2 weeks after operation, while the postoperative serum creatinine level was lower (P=0.001). Since the first week after operation, the reticulocyte count in EPO group was significantly higher than that in routine group (P<0.01). There was a negative correlation between hemoglobin and serum creatinine in EPO group at week 1 (r=-0.375, P=0.010) and week 2 (r=-0.386, P=0.008). During the treatment, 6 patients showed transient elevation of serum potassium, which returned to normal after symptomatic treatment, and no obvious adverse drug reactions were observed. 【Conclusion】 Continuous application of erythropoietin in the early stage after renal transplantation can significantly improve anemia in renal transplant patients and promote the recovery of renal function.

Association between residual cholesterol and the risk of subclinical renal damage / 西安交通大学学报(医学版)

【Objective】 Dyslipidemia has shown to be associated with cardiovascular, metabolic and renal diseases. This study aimed to investigate the association between residual cholesterol and the risk of subclinical renal damage (SRD). 【Methods】 A total of 2 342 participants were recruited from the previously established Hanzhong Adolescent Hypertension Study cohort. According to estimated glomerular filtration rate(eGFR) and urinary albumin-to-creatine ratio(uACR), the subjects were divided into SRD group and non-SRD group. The associations of residual cholesterol with eGFR, uACR, and the risk of SRD were analyzed by multiple linear and Logistic regression analyses. 【Results】 Residual cholesterol was positively correlated with uACR(r=0.081, P<0.001) but negatively correlated with eGFR (r=-0.091, P<0.001). Multiple linear regression analysis revealed that residual cholesterol was an influencing factor of uACR (β=0.075, P<0.001) and eGFR (β=-0.027, P<0.001) after adjustment for gender, age, smoke, alcohol, exercise, BMI, hypertension, diabetes and serum uric acid. In addition, Logistic regression analysis revealed that residual cholesterol was significantly associated with the risk of SRD independently of potential confounders [OR(95% CI)=1.387 (1.113-1.728), P<0.001]. Further subgroup analysis showed that residual cholesterol was significantly associated with the risk of SRD in women but not in men. 【Conclusion】 Residual cholesterol is a contributing factor in the risk of subclinical renal damage with gender-specific association.

Development of national secondary reference materials of urea and creatinine in frozen human serum / 中华检验医学杂志

Objective:To develop a national secondary reference material of Urea and Creatinine in frozen human serum as a standard for metrological traceability.Methods:According to JJF1343-2012 "General and Statistical Principles for Characterization of Reference Materials" and JJF 1006-1994 " Technical Norm of Primary Reference Material ", the homogeneity, stability, and commutability were evaluated;Using the JCTLM recommended methods, the value of the reference materials was assigned through collaboration with 6 accredited reference laboratories from Guangdong Provincial Hospital of Chinese Medicine, Beijing Aerospace General Hospital, Shenzhen Mindray Bio-Medical Electronics, Maccura Biotechnology, Beijing Leadman Biochemistry, and Zhejiang MedicalSystem Biotechnology. Uncertainty components including inhomogeneity, stability and value assignment were evaluated.Results:The results of one-way analysis of variance of homogeneity for the reference materials showed P>0.05, and the stability evaluation was less than the critical value of the t-test. The measured values were in the 95% confidence interval in the four conventional detection systems for commutability, and the certified values and expanded uncertainties were urea:(14.7±0.3) mmol/L ( k=2),Cr:(313.9±14.5) μmol/L ( k=2). Conclusion:The prepared secondary reference materials of urea and creatinine had promising homogeneity, stability, and commutable, the values of urea and creatinine concentration in reference materials were accurate and reliable.

Prevalence of albuminuria and its association with cardiovascular diseases in Chinese residents aged over 35 years / 中华内科杂志

Objective:To investigate the prevalence of albuminuria in Chinese residents aged >35 years and its potential association with cardiovascular disease (CVD).Methods:A total of 34 647 Chinese subjects aged ≥35 years were selected by stratified multi-stage random sampling from 2012 to 2015. Data were collected through questionnaires, physical examinations, and laboratory tests. Albuminuria was categorized into 3 types according to urinary albumin-to- creatinine ratio: normal (<30 mg/g), microalbuminuria (MAU, 30-300 mg/g), and macroalbuminuria (≥300 mg/g). Measurement data were expressed as xˉ±s, and t-tests were used for comparisons between indicators. Qualitative data were expressed as rate or constituent ratio, and the χ2 test or Kruskal-Wallis test was used to examine differences. Logistic regression was used for multivariate analyses. SAS 9.4 software was used for statistical analyses, and P<0.05 was considered statistically significant. Results:The prevalence of abnormal albuminuria was 19.1%; the prevalence was 17.2% for MAU and lower in males (13.8%) than females (20.1%, P<0.01). The risk of CVD was higher among subjects with MAU ( OR=1.23, 95% CI 1.12-1.35) and macroalbuminuria ( OR=1.86, 95% CI 1.50-2.32). When MAU was complicated by hypertension and diabetes mellitus, the CVD risk was 1.76 times higher. Conclusions:The prevalence of MAU is high among Chinese subjects aged 35 years and over. Those with MAU have higher CVD risk, especially those with hypertension and diabetes mellitus.

Cross-sectional associations between reproductive lifespan duration and urinary albumin-creatinine ratio / 中华内科杂志

Objective:To investigate the association between reproductive lifespan duration (RLD) and urinary albumin-creatinine ratio (UACR) in a Chinese postmenopausal population.Methods:This cross-sectional study included 11 055 naturally postmenopausal women from seven regions of China from May to December 2011. RLD was divided into four groups. Propensity score matching was performed to reduce bias, and logistic regressions and stratifications were conducted to investigate the association between RLD and increased UACR (≥30 mg/g). Mediation effect analysis was performed to quantify the effect of RLD on cardiovascular disease (CVD) induced by elevated UACR.Results:There were 2 373 participants with a RLD of 18-31 years, 2 888 participants with a RLD of 32-34 years, 2 472 participants with a RLD of 35-36 years, and 3 322 participants with a RLD of 37-50 years. The shortest RLD (18-31 years) group was characterized with older age ( P<0.001), a higher incidence of CVD ( P=0.025), and the highest level of UACR ( P<0.001). After adjusting for confounders, women with a longer RLD (37-50 years group) exhibited a lower risk of UACR elevation compared with those with the shortest RLD (18-31 years group) ( OR=0.72, 95% CI 0.64-0.82, P<0.001). Every 1-year extension in RLD was linked to a 2% reduction in the risk of UACR elevation ( OR=0.98, 95% CI 0.97-0.99, P<0.001). Stratified analysis revealed a more significant association between RLD and UACR in women who were a normal weight ( P=0.003) or overweight ( P=0.001), in those without CVD history ( P=0.001), and in those with impaired estimated glomerular filtration rate ( P=0.004). The mediation casual analysis showed that 3.0% of proteinuria inducing CVD events was mediated by RLD ( P=0.048). Conclusion:A longer RLD (37-50 years) is associated with a lower UACR in Chinese postmenopausal women.

Clinical characteristics and severe risk factors of tsutsugamushi disease / 中国热带医学

@#Abstract: Objective To investigate the clinical features and risk factors for severe tsutsugamushi disease, so as to provide reference for diagnosis and differentiation of severe tsutsugamushi disease as soon as possible. Methods The clinical data of 178 cases of inpatients with tsutsugamushi disease admitted to the Guangzhou Eighth People's Hospital, Guangzhou Medical University from January 2016 to September 2021 were collected and analyzed according to their gender, age, underlying diseases, clinical characteristics at admission, laboratory examination results within 24 hours of admission and epidemiological history. The patients were divided into the severe group and the non-severe group according to the diagnostic criteria. The data of clinical characteristics, laboratory examination and prognosis of the two groups were compared. Multivariate logistic regression analysis was performed on the variables with statistical significance and the receiver operating characteristic curve (ROC) was drawn. Results A total of 178 patients were included in this study, with 37 in the severe group and 141 in the non-severe group. Compared with the non-severe group, the age of the severe group was older, the underlying diseases were more, the incidence of dyspnea and the levels of white blood cell, total bilirubin, aspartate aminotransferase, lactate dehydrogenase, cystatin C, uric acid and serum creatinine were significantly increased, the levels of platelet and albumin were significantly decreased (all P<0.05). The dyspnea [odds ratio (OR value)=8.93, 95% confidence interval (CI): 1.200-66.424; P=0.032], total bilirubin (OR=1.091, 95%CI: 1.028-1.159; P=0.004) and serum creatinine (OR=1.052, 95%CI: 1.004-1.102; P=0.033) were independent risk factors for severe tsutsugamushi disease. The area under ROC curve of total bilirubin and serum creatinine were 0.777 and 0.764, respectively (both P<0.01), indicating high predictive value for severe tsutsugamushi disease. The optimal cut-off value for total bilirubin was 23.01 µmol/L, with a sensitivity of 54.10% and a specificity of 90.60%; the optimal cut-off value for creatinine was 126.45 µmol/L, with a sensitivity of 43.20% and a specificity of 100.00%. The case fatality rate of severe tsutsugamushi disease was 2.70%. Conclusions The patients with severe tsutsugamushi disease are older, and have more underlying diseases. Dyspnea, increased total bilirubin and elevated serum creatinine are independent risk factors for severe tsutsugamushi disease, which can help in the early identification of severe tsutsugamushi disease early.