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1.
Pediatr Transplant ; 28(4): e14776, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38778714

RESUMO

BACKGROUND: It is essential to have an accurate assessment of the renal function of patients with chronic kidney disease to monitor, treat, and predict further development of the condition. Measurement of renal function in terms of glomerular filtration rate (GFR) requires either urine or blood sampling, but especially in children, more simple methods of measurement are preferable. The main objective of this study was to examine if the estimated GFR (eGFR) calculated with different cystatin-C-based equations was comparable to the GFR measured by a radiotracer (mGFR) in pediatric patients. METHODS: In this retrospective study, 28 pediatric patients contributed with 73 pairs of measurements collected within 5 years. Bland-Altman Limits of Agreement were used to evaluate the performance and accuracy of two different cystatin-C-based estimates, the CKiDCrea-CysC and the CKiDU25 respectively, compared to an mGFR based on plasma clearance of technetium-99m-diethylenetriaminepentaacetic acid or chromium-51-ethylenediaminetetraacetic acid. RESULTS: Using the CKiDCrea-CysC equation, 58.9% of the datasets were within P10 and 87.7% were within P30. The mean difference was 4.8 mL/min/1.73m2 (standard deviation: 8.5 mL/min/1.73m2) and tended to overestimate GFR and thereby overrate the kidney function within the entire GFR range. Using the CKiDU25 equation, 53.4% were within P10 and 93.2% within P30. The mean difference was -2.9 mL/min/1.73m2 (standard deviation: 8.4 mL/min/1.73m2), but the difference varied with the GFR value. CONCLUSIONS: A cystatin-C-based eGFR provides a viable substitute for monitoring renal function in pediatric patients with chronic kidney disease. However, it has a lower accuracy than mGFR and can therefore not replace mGFR in clinical use.


Assuntos
Cistatina C , Taxa de Filtração Glomerular , Insuficiência Renal Crônica , Humanos , Cistatina C/sangue , Criança , Feminino , Masculino , Estudos Retrospectivos , Insuficiência Renal Crônica/fisiopatologia , Adolescente , Pré-Escolar , Testes de Função Renal , Pentetato de Tecnécio Tc 99m , Compostos Radiofarmacêuticos , Radioisótopos de Cromo , Lactente
2.
J Nephrol ; 36(9): 2457-2465, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37093492

RESUMO

BACKGROUND: In late 2018, the production of 51Chromium-labelled ethylenediamine tetra-acetic acid (51Cr-EDTA), a validated and widely used radio-isotopic tracer for measuring glomerular filtration rate, was halted. Technetium-99m-diethylenetriaminepentaacetic acid (99mTc-DTPA) has been validated for GFR measurement with a single bolus injection, a procedure not suitable in patients with extracellular compartment hyperhydration. In such cases, a bolus followed by continuous infusion of the tracer is required. The aim of this study was to evaluate whether 99mTc-DTPA with the infusion protocol can replace 51Cr-EDTA for GFR measurement. METHODS: We conducted a prospective single centre study during February and March 2019. All patients referred for GFR measurement received both radiotracers simultaneously: 51Cr-EDTA and 99mTc-DTPA bolus and continuous infusion were administered concomitantly through the same intravenous route. Over four and a half hours, plasma and urine samples were collected to calculate urinary and plasma clearance. RESULTS: Twenty-two patients were included (mean age 63.4 ± 17.5 years; 68% men). Mean urinary clearance of 51Cr-EDTA and 99mTc-DTPA was 52.4 ± 22.5 mL/min and 52.8 ± 22.6 mL/min, respectively (p = 0.47), with a mean bias of 0.39 ± 2.50 mL/min, an accuracy within 10% of 100% (95% CI 100; 100) and a Pearson correlation coefficient of 0.994. Mean plasma clearance of 51Cr-EDTA and 99mTc-DTPA was 54.8 ± 20.9 mL/min and 54.4 ± 20.9 mL/min, respectively (p = 0.61), with a mean bias of - 0.43 ± 3.89 mL/min, an accuracy within 10% of 77% (95% CI 59; 91) and a Pearson correlation coefficient of 0.983. CONCLUSIONS: Urinary and plasma clearance of 99mTc-DTPA can be used with the infusion protocol to measure GFR.


Assuntos
Nefropatias , Pentetato de Tecnécio Tc 99m , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Radioisótopos de Cromo , Ácido Edético , Taxa de Filtração Glomerular , Ácido Pentético , Estudos Prospectivos , Tecnécio
3.
Medicine (Baltimore) ; 101(3): e28608, 2022 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-35060531

RESUMO

ABSTRACT: Plasma disappearance curves using multiple blood samples are a recognized reference method for measuring glomerular filtration rate (GFR). However, there is no consensus on the protocol for this type of measurement. A two-compartment model is generally considered acceptable for the mathematical description of the concentration-time decay curve. The impact of the fitting procedure on the reported GFR has not been questioned.We defined 8 different fitting procedures to calculate the area under the curve, and from this area under the curve, the GFR. We applied the 8 fitting methods (all considering a full concentration-time curve) on the multiple sample data (8 samples) of 20 children diagnosed with Duchenne muscular dystrophy. We evaluated the effect (variability) on the reported GFR from the different fitting methods and compared these results with GFR-values calculated from late samples only (samples after 120 minutes) and from one-sample methods.In 6 out of 20 cases, the fitting methods on the full concentration-time curve resulted in very different reported GFR-values, mainly because some methods were not able to fit the data, or methods resulted in GFR-values ranging from 0 to 120 mL/min. The reported GFR-result therefore strongly depends on the fitting method, making the full concentration-time method less robust than expected. Compared with a consensus reference GFR, the late sample models did not show fitting issues and may therefore be considered as more robust. Also the one-sample methods showed acceptable accuracy.The late sample methods (using 3 time-points) provide robust and reliable methods to determine GFR.


Assuntos
Radioisótopos de Cromo/sangue , Ácido Edético/sangue , Taxa de Filtração Glomerular/fisiologia , Rim/metabolismo , Adolescente , Biomarcadores/análise , Criança , Pré-Escolar , Feminino , Humanos , Testes de Função Renal/métodos , Masculino , Taxa de Depuração Metabólica , Adulto Jovem
4.
PLoS One ; 16(8): e0256234, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34398928

RESUMO

BACKGROUND: Bariatric surgery (BS) might be a nephroprotective treatment in obese patients with chronic kidney disease (CKD), and the non-linear relation between body surface area (BSA) and extracellular fluid volume (ECFV) in obese people raises the question of the most relevant way to scale glomerular filtration rate (GFR) for assessing renal function changes after BS. METHODS: We screened 1774 BS candidates and analysed 10 consecutive participants with CKD stage 3. True GFR (mGFR), measured by the renal clearance of 51Cr-ethylenediaminetetraacetic acid (EDTA), was scaled either to BSA (mGFRBSA) or to ECFV measured by 51Cr-EDTA distribution volume (mGFRECFV) before and one year after BS. RESULTS: The 10 candidates for BS had a mean body mass index of 43.3 ± 3.6 kg/m2 and a mean GFR of 48 ± 8 mL/min/1.73 m2. Six participants had a sleeve gastrectomy and four had a Roux-en-Y gastric bypass. One year after BS, ECFV decreased (23.2 ± 6.2 to 17.9 ± 4.3 L, p = 0.001), absolute mGFR was not significantly modified (74 ± 23 versus 68 ±19 mL/min), mGFRBSA did not change significantly (53 ± 18 versus 56 ± 17 mL/min/1.73 m2) whereas mGFRECFV significantly increased (42 ± 13 versus 50 ± 14 mL/min/12.9 L, p = 0.037). The relation between mGFRECFV and mGFRBSA was different from the identity line before (p = 0.014) but not after BS (p = 0.09). CONCLUSION: There is a difference between mGFRBSA and mGFRECFV following BS and the latter might better reflect the adequacy between renal function and corpulence.


Assuntos
Cirurgia Bariátrica/métodos , Líquido Extracelular/metabolismo , Taxa de Filtração Glomerular , Obesidade Mórbida/fisiopatologia , Insuficiência Renal Crônica/fisiopatologia , Idoso , Biomarcadores/análise , Superfície Corporal , Radioisótopos de Cromo/farmacocinética , Ácido Edético/farmacocinética , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Obesidade Mórbida/diagnóstico , Obesidade Mórbida/metabolismo , Obesidade Mórbida/cirurgia , Insuficiência Renal Crônica/diagnóstico , Insuficiência Renal Crônica/metabolismo , Insuficiência Renal Crônica/cirurgia , Resultado do Tratamento
5.
Methods Mol Biol ; 2255: 159-169, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34033102

RESUMO

Cytotoxic T cell-induced cell death is well documented. Cytotoxic T cell releases various cytolytic proteins. The cytolytic proteins induce target cell death. T cell-induced cell death can be measured by the lytic assay. One of the well-known lytic assays uses radioactive tracer, Chromium-51 (51Cr), and detects the amount of 51Cr released from target cells. This assay can detect cell death and the efficiency of the T cell-induced cell death by coculture effector cells (T cells) and target cells. This assay can determine the kinetics of the cell lysis. The issue of this approach is the use of radioactive material. This chapter describes measuring T cell-induced cell death by determining the epigenetic remodeling and the release of cytolytic proteins. Determine the efficiency of T cell-induced cell death by using a flow cytometry-based detection method.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Radioisótopos de Cromo/análise , Neoplasias do Colo/patologia , Testes Imunológicos de Citotoxicidade/métodos , Citometria de Fluxo/métodos , Linfoma de Células B/patologia , Linfócitos T Citotóxicos/imunologia , Adenocarcinoma/imunologia , Adenocarcinoma/metabolismo , Adenocarcinoma/patologia , Animais , Morte Celular , Neoplasias do Colo/imunologia , Neoplasias do Colo/metabolismo , Linfoma de Células B/imunologia , Linfoma de Células B/metabolismo , Camundongos , Células Tumorais Cultivadas
6.
Hemodial Int ; 25(2): 198-204, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33274575

RESUMO

INTRODUCTION: A reduced erythrocyte lifespan potentially explains the low hemoglobin A1c values found in hemodialysis patients. However, data supporting this notion in patients with type 2 diabetes is unclear. We evaluated the erythrocyte lifespan in patients with type 2 diabetes undergoing long-term hemodialysis and investigated potential predictors of erythrocyte lifespan. METHODS: Long-term hemodialysis patients with type 2 diabetes and type 2 diabetes patients without nephropathy (estimated glomerular filtration rate > 60 mL/min/1.73 m2 ) were included. The erythrocyte lifespan was measured using chromium-51 (51 Cr)-labeled erythrocytes. Blood radiotracer activity was measured six to nine times over a period of 3-5 weeks to determine the erythrocyte lifespan of each patient. Biochemical markers were obtained five times over 16 weeks and associated with the erythrocyte lifespan. FINDINGS: Type 2 diabetes patients undergoing hemodialysis (N = 13) had a significantly shorter median erythrocyte lifespan of 49.7 (interquartile range [IQR] = 44.1-58.6) days compared with 64.2 (IQR = 62.6-83.5) days in the control group (N = 10) (P ˂ 0.001) with a difference between medians of 14.5 (95% confidence interval = 8.1-38.8) days. In the hemodialysis group, no association could be detected between the erythrocyte lifespan and markers of hemolysis, level of inflammation, or urea. DISCUSSION: A reduced erythrocyte lifespan was detected in type 2 diabetes patients undergoing long-term hemodialysis. This may contribute to the reduced hemoglobin A1c values observed in the type 2 diabetic hemodialysis population. An association could not be detected between the erythrocyte lifespan and biochemical markers of hemolysis or inflammation.


Assuntos
Diabetes Mellitus , Longevidade , Radioisótopos de Cromo , Eritrócitos , Humanos , Diálise Renal/efeitos adversos
7.
Am J Kidney Dis ; 77(5): 673-683.e1, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33301877

RESUMO

RATIONALE AND OBJECTIVE: Glomerular filtration rate (GFR) estimation based on creatinine and cystatin C (eGFRcr-cys) is more accurate than estimated GFR (eGFR) based on creatinine or cystatin C alone (eGFRcr or eGFRcys, respectively), but the inclusion of creatinine in eGFRcr-cys requires specification of a person's race. ß2-Microglobulin (B2M) and ß-trace protein (BTP) are alternative filtration markers that appear to be less influenced by race than creatinine is. STUDY DESIGN: Study of diagnostic test accuracy. SETTING AND PARTICIPANTS: Development in a pooled population of 7 studies with 5,017 participants with and without chronic kidney disease. External validation in a pooled population of 7 other studies with 2,245 participants. TESTS COMPARED: Panel eGFR using B2M and BTP in addition to cystatin C (3-marker panel) or creatinine and cystatin C (4-marker panel) with and without age and sex or race. OUTCOMES: GFR measured as the urinary clearance of iothalamate, plasma clearance of iohexol, or plasma clearance of [51Cr]EDTA. RESULTS: Mean measured GFRs were 58.1 and 83.2 mL/min/1.73 m2, and the proportions of Black participants were 38.6% and 24.0%, in the development and validation populations, respectively. In development, addition of age and sex improved the performance of all equations compared with equations without age and sex, but addition of race did not further improve the performance. In validation, the 4-marker panels were more accurate than the 3-marker panels (P < 0.001). The 3-marker panel without race was more accurate than eGFRcys (percentage of estimates greater than 30% different from measured GFR [1 - P30] of 15.6% vs 17.4%; P = 0.01), and the 4-marker panel without race was as accurate as eGFRcr-cys (1 - P30 of 8.6% vs 9.4%; P = 0.2). Results were generally consistent across subgroups. LIMITATIONS: No representation of participants with severe comorbid illness and from geographic areas outside of North America and Europe. CONCLUSIONS: The 4-marker panel eGFR is as accurate as eGFRcr-cys without requiring specification of race. A more accurate race-free eGFR could be an important advance.


Assuntos
Negro ou Afro-Americano , Creatinina/metabolismo , Cistatina C/metabolismo , Taxa de Filtração Glomerular , Oxirredutases Intramoleculares/metabolismo , Lipocalinas/metabolismo , Insuficiência Renal Crônica/diagnóstico , População Branca , Microglobulina beta-2/metabolismo , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , População Negra , Estudos de Casos e Controles , Radioisótopos de Cromo , Ácido Edético , Feminino , Humanos , Iohexol , Ácido Iotalâmico , Masculino , Pessoa de Meia-Idade , Insuficiência Renal Crônica/etnologia , Insuficiência Renal Crônica/metabolismo , Reprodutibilidade dos Testes , Índice de Gravidade de Doença , Adulto Jovem
8.
Transfusion ; 61(2): 393-403, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33166412

RESUMO

BACKGROUND: The purpose of our studies was to determine if fecal blood loss can provide a quantitative measure of bleeding at platelet counts of 20 000/µL or less in patients with hypoproliferative thrombocytopenia and to document the effects of different prophylactic platelet transfusion triggers on fecal blood loss. METHODS AND MATERIALS: Patients had an aliquot of their autologous red blood cells (RBCs) labeled with 51 Cr. Following reinjection of their radiolabeled RBCs, all feces and a daily blood sample were collected to determine fecal blood loss per day. Three different studies were performed in patients with thrombocytopenia: The first was in patients with thrombocytopenia with aplastic anemia who were not receiving platelet transfusions, and the other two trials involved thrombocytopenic patients with cancer who were receiving prophylactic platelet transfusions at platelet transfusion triggers of 5000/µL, 10 000/µL, or 20 000/µL. RESULTS: In patients with thrombocytopenia not receiving platelet transfusions, fecal blood loss does not increase substantially until platelet counts are 5000/µL or less. When platelet transfusions are given prophylactically to patients with cancer with chemotherapy-induced thrombocytopenia at platelet counts of 5000/µL or less, fecal blood loss and red cell transfusion requirements are the same as those for patients transfused prophylactically at higher transfusion triggers of 10 000 platelets/µL or 20 000 platelets/µL. However, the total number of platelet transfusions needed increases significantly, and the duration of the patient's thrombocytopenia tends to be longer at the higher platelet transfusion thresholds. CONCLUSION: A prophylactic platelet transfusion threshold of 5000/µL or greater is sufficient to maintain hemostasis in patients with thrombocytopenia.


Assuntos
Hemorragia Gastrointestinal/diagnóstico , Hemostasia , Sangue Oculto , Transfusão de Plaquetas , Trombocitopenia/terapia , Anemia Aplástica/sangue , Anemia Aplástica/complicações , Radioisótopos de Cromo , Contagem de Eritrócitos , Hemorragia Gastrointestinal/etiologia , Hemorragia Gastrointestinal/prevenção & controle , Hemorragia/etiologia , Hemorragia/terapia , Humanos , Neoplasias/complicações , Projetos Piloto , Contagem de Plaquetas , Transfusão de Plaquetas/estatística & dados numéricos , Estudos Prospectivos , Ensaios Clínicos Controlados Aleatórios como Assunto/estatística & dados numéricos , Risco , Trombocitopenia/sangue , Trombocitopenia/complicações
10.
J Clin Pharm Ther ; 45(5): 1114-1119, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32519358

RESUMO

WHAT IS KNOWN AND OBJECTIVES: In Europe, the pharmaceutical supply of chromium-51 has been stopped. However, this isotope is necessary for the evaluation of glomerular filtration rates. It is possible to replace it with technetium-99m, but the validation of this change in the measurement method must be carried out. METHODS: A retrospective analysis of chromium-51 data from January 2018 to January 2019 was performed, followed by a study from January 2019 to January 2020 using the technetium tracer. The patients were different in the both study groups, and none had an eGFR below 50 mL min-1 . A cost analysis was performed. Patient exposure to ionizing radiation was studied for both methods. RESULTS AND DISCUSSION: Seventy-eight patients were included in the study. In total, 42 EDTA-51 Cr and 36 DTPA-99m Tc examinations were conducted and compared. There were no significant differences between the methods used to assess renal function (P = .351). The results of cost analysis and patient radiation exposure were in favour of DTPA-99m Tc examinations. WHAT IS NEW AND CONCLUSION: Within the limitations of a retrospective study of two patient cohorts, there was no significant difference between the results obtained with chromium-51 and technetium-99m tracers. In addition, with the use of DTPA-99m Tc, operating costs and patient exposure to ionizing radiation were reduced, and clinical activity was maintained for the patients' benefit. Radiopharmacists are able to react quickly to supply contingencies, reduce operating costs and maintain the quality of medical examinations.


Assuntos
Taxa de Filtração Glomerular/fisiologia , Rim/diagnóstico por imagem , Farmacêuticos/organização & administração , Serviço de Farmácia Hospitalar/organização & administração , Radioisótopos de Cromo/farmacocinética , Feminino , Humanos , Testes de Função Renal/métodos , Transplante de Rim/métodos , Doadores Vivos , Masculino , Pessoa de Meia-Idade , Papel Profissional , Compostos Radiofarmacêuticos/farmacocinética , Estudos Retrospectivos , Pentetato de Tecnécio Tc 99m/farmacocinética
11.
Ann Biol Clin (Paris) ; 78(3): 319-322, 2020 06 01.
Artigo em Francês | MEDLINE | ID: mdl-32540818

RESUMO

The purpose of this work was to compare the measured red-cell volume (RCV) using sodium pertechnétate [RCV-99mTc] compared to the reference technique using sodium radiochromate [RCV-51Cr] and to assess the influence of technetium-99 elution on the RCV-99mTc value. Ten patients had simultaneous measurements of RCV-99mTc and RCV-51Cr. Elution of Tc-99m from red blood cells was 2.9% and led to an average overestimation of RCV-99mTc of 3.7%. The introduction of individual tracer elution rates in the RCV-99mTc calculation corrects this overestimation.


Assuntos
Radioisótopos de Cromo/farmacologia , Volume de Eritrócitos/efeitos dos fármacos , Eritrócitos/citologia , Eritrócitos/efeitos dos fármacos , Marcação por Isótopo/métodos , Tecnécio/farmacologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Relação Dose-Resposta a Droga , Contagem de Eritrócitos/métodos , Feminino , Hematócrito/métodos , Humanos , Marcação por Isótopo/efeitos adversos , Masculino , Pessoa de Meia-Idade , Técnica de Diluição de Radioisótopos
12.
Scand J Clin Lab Invest ; 80(5): 408-411, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32362172

RESUMO

The issue of whether 99mTc-DTPA can replace 51Cr-EDTA for measurement of plasma clearance as a surrogate for glomerular filtration rate (GFR) is of great relevance to daily clinical practice. Prompted by the shortage of 51Cr-EDTA we conducted a head-to-head comparison in patients attending our department for GFR determination. The two tracers (3.7 MBq of 51Cr-EDTA and 8 MBq of 99mTc-DTPA) were administered intravenously immediately after each other, and the standard number of blood samples were drawn. Fifty-four patients were enrolled. In 51 of these, single-sample measurement was performed with the following results: GFREDTA was 84.6 ± 23.3 mL/min, GFRDTPA was 84.2 ± 24.7 mL/min. The mean difference was 0.4 ± 2.8 mL/min, p = 0.32, and results based on the two tracers were highly correlated (r = 0.995). GFRDTPA exceeded GFREDTA at high GFR values (difference < 0 at GFREDTA >91.4 mL/min) and vice versa (difference > 0 at GFREDTA < 91.4 mL/min). However, differences fell within few GFR units that most often will have no clinical consequence. We therefore conclude that 99mTc-DTPA can replace 51Cr-EDTA for single-sample determination of GFR in a clinical setting.


Assuntos
Ácido Edético/farmacocinética , Taxa de Filtração Glomerular/fisiologia , Renografia por Radioisótopo/métodos , Compostos Radiofarmacêuticos/farmacocinética , Pentetato de Tecnécio Tc 99m/farmacocinética , Administração Intravenosa , Idoso , Radioisótopos de Cromo , Feminino , Humanos , Rim/fisiologia , Masculino , Pessoa de Meia-Idade , Renografia por Radioisótopo/normas
13.
Ann Pharm Fr ; 78(4): 335-342, 2020 Jul.
Artigo em Francês | MEDLINE | ID: mdl-32439129

RESUMO

OBJECTIVES: Last October, the nuclear medicine departments were informed of the closure of the chromium-51 production line for clinical use. This radionuclide has different diagnostic indications in nephrology and hematology. It was therefore essential to set up alternative exploration protocols to overcome this production stoppage. METHODS: Chromium-51 EDTA has been replaced by technetium-99m DTPA for the determination of glomerular filtration rates. Sodium chromate was substituted by sodium pertechnetate for the determination of globular volumes. A retrospective analysis of the chromium-51 data was performed followed by a prospective study, from January to December 2019 for technetium tracers. RESULTS: One hundred and forty-four patients were included in the study. Forty-two EDTA-51Cr and 30 DTPA-99mTc exams were conducted and compared. There were no significant differences between the methods used to assess renal function (P=0.355). For the determination of blood cell and plasma volumes, 47 tests with 51Cr and 125I and 25 tests with 99mTc and 125I were performed and compared. There were no significant differences in the determination of total (P=0.325) and globular (P=0.148) volumes. CONCLUSIONS: The study carried out shows that there is no significant difference between the results obtained with chromium-51 and technetium tracers. As a result, clinical activity was maintained in good conditions.


Assuntos
Radioisótopos de Cromo/efeitos adversos , Medicina Nuclear/métodos , Compostos Radiofarmacêuticos/efeitos adversos , Adulto , Volume Sanguíneo , Taxa de Filtração Glomerular , Humanos , Testes de Função Renal , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Reprodutibilidade dos Testes , Pentetato de Tecnécio Tc 99m
14.
Nucl Med Commun ; 41(6): 589-596, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32282637

RESUMO

The withdrawal of Cr-chromate has meant that the technique commonly used for direct measurement of red cell volume has had to be replaced. Most centres moved to a Tc erythrocyte label, however, Tc is known to dissociate over time. We have investigated an alternative technique using an In-chloride and tropolone solution and tested this both in vitro and in vivo. Initial in-vitro and in-vivo work, which included a check of the stability of the radio-labelled product at one hour, demonstrated this label to be stable over this time period. To date, 20 patients have undergone this technique and results show that this technique is a viable alternative to Cr-chromate particularly for patients with splenomegaly who require late sampling. This procedure is now in routine use in our institution.


Assuntos
Radioisótopos de Cromo/metabolismo , Volume de Eritrócitos , Radioisótopos de Índio/metabolismo , Marcação por Isótopo/métodos , Humanos
15.
J Endourol ; 34(3): 394-399, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31973616

RESUMO

Objectives: To analyze the preoperative variables associated to the postoperative glomerular filtration rate (GFR) outcomes after nephrectomy for benign and malignant conditions, measured by the reference isotopic technique 51Cr-ethylene diamine tetra-acetic (51Cr-EDTA) and to create a model to predict the short-term postoperative GFR. Secondary aim was to evaluate which of the common equations for GFR estimation (Cockcroft-Gault, Modification of Diet in Renal Disease [MDRD] or Chronic Kidney Disease Epidemiology Collaboration [CKD-EPI]) has the best correlation with the 51Cr-EDTA. Methods: Patients undergoing unilateral nephrectomy from 2014 to 2018 were selected. Pre- and postoperative variables were prospectively collected. Univariate and multivariate analyses were done to identify independent risk factors associated with renal function outcomes and to create a model to predict the postoperative GFR. Correlation analyses were performed to evaluate the performance of various serum creatinine-based equations for GFR estimation compared with 51Cr-EDTA. Results: In total, 107 patients were evaluated. After univariate and multivariate analyses, older age (p = 0.008), higher split function of the operated kidney on dimercaptosuccinic acid (DMSA) scintigraphy (p < 0.001), and lower preoperative 51Cr-EDTA (p < 0.001) were independent risk factors for higher GFR decline. Correlation analyses showed that GFR estimated by CKD-EPI equation had the best concordance to GFR measured by 51Cr-EDTA. Conclusions: Based on our findings age, DMSA and lower preoperative 51Cr-EDTA are predictors of postoperative renal function after unilateral nephrectomy. For the assessment of estimated GFR, CKD-EPI equation appears to have the best concordance with 51Cr-EDTA.


Assuntos
Radioisótopos de Cromo/farmacocinética , Ácido Edético/farmacocinética , Nefrotomia , Insuficiência Renal Crônica/etiologia , Feminino , Taxa de Filtração Glomerular , Humanos , Testes de Função Renal , Masculino , Pessoa de Meia-Idade , Modelos Biológicos , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/fisiopatologia , Insuficiência Renal Crônica/fisiopatologia , Fatores de Risco
16.
Methods Enzymol ; 631: 497-512, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31948566

RESUMO

Natural killer (NK) cells are cytotoxic lymphocytes that belong to the innate lymphoid cells. They have the ability to attack tumor cells that lack ligands of inhibitory NK receptors and/or express ligands of activating NK receptors. The most important ligands of inhibitory NK receptors are major histocompatibility complex (MHC) class I molecules, which are down regulated on many tumor cells. Several ligands of activating NK receptors, in contrast, are up regulated on tumor cells due to cellular and genotoxic stress. Due to these features, NK cells constitute an important element of the tumor immunosurveillance and are explored as a cellular tool for tumor immunotherapy. Therefore, it is important to be able to monitor the cytotoxic activity of NK cells reliably in preclinical animal models as well as in patients. It is also of interest to determine the susceptibility of tumor cells toward NK cell-mediated cellular cytotoxicity. The 51Cr-release assay monitors the lysis of target cells by NK cells and is suitable to address both questions. We describe here the experimental set-up of this classic cytotoxicity assay in detail.


Assuntos
Radioisótopos de Cromo , Testes Imunológicos de Citotoxicidade/métodos , Células Matadoras Naturais/imunologia , Neoplasias/imunologia , Animais , Linhagem Celular Tumoral , Citotoxicidade Imunológica , Humanos , Imunoterapia , Neoplasias/terapia
17.
Nephrol Dial Transplant ; 35(3): 519-526, 2020 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-30649437

RESUMO

BACKGROUND: Renal dysfunction is a serious late complication after liver transplantation (LTX), but there are no studies addressing the early changes associated with this complication. METHODS: We prospectively studied glomerular filtration rate (GFR) before and at 1, 3 and 12 weeks after LTX using 51Cr-labelled ethylenediaminetetraacetic acid clearance in 37 adult consecutive patients who underwent non-acute first LTX. RESULTS: The mean (±SD) age was 49.5 ± 9.5 years, and the male:female sex ratio was 21:16. Diagnoses were autoimmune liver diseases (17), alcoholic cirrhosis (10) and other diseases (10). Immunosuppressive treatment consisted predominantly of triple-drug therapy. A total of 27 of the 37 patients were eligible for GFR analysis at all times. The mean (±SD) GFR was 86 ± 26 mL/min/1.73 m2 before LTX, and 77 ± 30 mL/min/1.73 m2 at 1 week, 64 ± 27 mL/min/1.73 m2 at 3 weeks and 64 ± 23 mL/min/1.73 m2 at 12 weeks after LTX, comparable to a reduction in mean GFR compared with baseline values of 10% (P = 0.1907), 25% (P = 0.0010) and 26% (P = 0.0007). Age and number of blood transfusions during surgery were identified as risk factors for this decline as well as gender, but not pre-transplant diagnosis, model of end-stage liver disease score, cold ischaemia time or post-transplant area under the curve tacrolimus during Days 0-14. CONCLUSIONS: Using measured rather than estimated GFR, our results show that severe renal impairment occurs during the first week after LTX. These results emphasize the need for more studies addressing renoprotective treatment strategies.


Assuntos
Injúria Renal Aguda/diagnóstico , Biomarcadores/metabolismo , Radioisótopos de Cromo/metabolismo , Ácido Edético/metabolismo , Transplante de Fígado/efeitos adversos , Injúria Renal Aguda/etiologia , Injúria Renal Aguda/metabolismo , Feminino , Taxa de Filtração Glomerular , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Risco
18.
Nucl Med Commun ; 40(12): 1224-1229, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31633648

RESUMO

AIM: The study aimed to investigate whether a systematic difference exists between Cr EDTA and Tc DTPA for measurement of glomerular filtration rate (GFR). METHODS: The distribution of GFR results from candidates attending the Royal Free Hospital for assessment of suitability for kidney donation was compared before and after the change from Cr EDTA to Tc DTPA using three-sample slope-intercept GFR calculation with samples at 2, 3, and 4 hours. A second cohort of oncology patients attending Leeds Teaching Hospitals NHS Trust underwent simultaneous GFR measurement with both tracers by full characterisation of the plasma clearance curve with nine samples between 5 minutes and 8 hours post-injection. Three-sample slope-intercept GFR was also calculated for comparison with cohort 1. RESULTS: From the first cohort, a statistically significant (P = 0.008) systematic difference of 5.8% (95% confidence interval: 1.5%-10.1%) was found in the three-sample slope-intercept GFR, with Tc DTPA giving the higher result. From the second cohort, a statistically significant (P = 0.00001) systematic difference of 2.9% (95% confidence interval: 1.8%-3.9%) was found in three-sample slope-intercept GFR, with Tc DTPA giving the higher result. There was no statistically significant difference between the tracers when GFR was calculated by full characterisation of the plasma clearance curve. CONCLUSION: There is a small systematic difference between GFR measured with Tc DTPA and Cr EDTA using abbreviated techniques, which is removed when GFR is calculated by full characterisation of the plasma clearance curve. The difference is not clinically significant in the context of intra-patient variability of GFR measurement.


Assuntos
Radioisótopos de Cromo , Ácido Edético , Taxa de Filtração Glomerular , Testes de Função Renal/métodos , Pentetato de Tecnécio Tc 99m , Adulto , Idoso , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
19.
Scand J Clin Lab Invest ; 79(7): 463-467, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31502901

RESUMO

Both 99mTc-DTPA and 51Cr-EDTA are widely used to determine glomerular filtration rate (GFR), but few direct comparative studies exist. The shortage of 51Cr-EDTA makes a direct comparison highly relevant. The aim of the study was to investigate if there is any clinically relevant difference between plasma clearance of 99mTc-DTPA and 51Cr-EDTA. Patients ≥18 years of age referred for routine GFR measurement by 51Cr-EDTA were prospectively enrolled. The two tracers (10 MBq 99mTc-DTPA (CaNa3-DTPA) and 2.5 MBq 51Cr-EDTA) were intravenously injected at time zero. A standard 4-sample technique was applied with samples collected at 180, 200, 220 and 240 min, if the estimated GFR (eGFR) was ≥30 mL/min. A comparison of single-sample GFR based on the 200 min sample was also conducted. Fifty-six patients were enrolled in the study. All patients had an estimated GFR >30 mL/min/1.73 m2. No patients suffered from ascites or significant oedema. The mean 51Cr-EDTA plasma clearance was 82 mL/min (range 16-226). The plasma clearances determined by the two methods were highly correlated (r = 0.993). The plasma clearance was significantly higher when measured by 99mTc-DTPA than by 51Cr-EDTA (p = 0.01), but the numerical difference was minimal (mean difference 1.4 mL/min; 95% limits of agreement (LOA) -6.6 to 9.4). The difference between the two methods was independent of the level of renal function. Similar results were found for one-sample GFR. No clinically relevant differences were found between the plasma clearance of 99mTc-DTPA and that of 51Cr-EDTA. Therefore, 99mTc-DTPA can replace 51Cr-EDTA when needed.


Assuntos
Radioisótopos de Cromo/sangue , Ácido Edético/sangue , Renografia por Radioisótopo/métodos , Compostos Radiofarmacêuticos/sangue , Pentetato de Tecnécio Tc 99m/sangue , Adulto , Idoso , Idoso de 80 Anos ou mais , Radioisótopos de Cromo/farmacocinética , Feminino , Taxa de Filtração Glomerular , Humanos , Masculino , Pessoa de Meia-Idade , Renografia por Radioisótopo/normas , Compostos Radiofarmacêuticos/farmacocinética , Pentetato de Tecnécio Tc 99m/farmacocinética , Adulto Jovem
20.
Eur J Radiol ; 117: 209-215, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31221527

RESUMO

OBJECTIVES: To evaluate the performance of dynamic contrast-enhanced MRI measurement of glomerular filtration rate (GFR) compared with the reference standard technique of urinary clearance of 51Cr-EDTA. PATIENTS AND METHODS: All kidney transplant recipients (KTRs) with an indication for non-urgent contrast-enhanced MRI at our institution were prospectively included between 2008 and 2012. Renographies were acquired by low-dose dynamic contrast-enhanced MRI (DCE-MRI) then fitted with a two-compartment pharmacokinetic model. MR-GFR was compared with reference isotopic measurements using Bland-Altman diagrams, intraclass correlation coefficient (ICC) and concordance rates. RESULTS: Forty-two KTRs (mean age 51.5 years, 26-74) were analyzed. Mean estimated GFR was 48.5 ± 27 mL/min/1.73m2 (24-178 mL/min). The mean bias was +13.2 mL/min (6.4-20.0, +36.9%) ranging from -31.0 mL/min (-41.7%) to +101.4 mL/min (+89.2%) with a large variability (standard-deviation: 22.3 mL/min; limits of agreement: [-30.6 (-43.3--18.9); +57.0 (45.3-68.7)]). The ICC was 0.32 (0.02-0.56) and the concordance rate was 28.6% (14.9-42.2). CONCLUSIONS: The large variability of MR-GFR compared with the reference technique precludes its use in KTRs, whose anatomical peculiarities make standardization of arterial input function (AIF) difficult.


Assuntos
Radioisótopos de Cromo/farmacocinética , Ácido Edético/farmacocinética , Transplante de Rim , Imageamento por Ressonância Magnética , Transplantados , Adulto , Idoso , Feminino , Taxa de Filtração Glomerular , Humanos , Testes de Função Renal/métodos , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
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