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Resumen Los anticuerpos monoclonales marcados con radionucleidos fueron en sus inicios ampliamente empleados para el estudio de diversas enfermedades, fundamentalmente oncológicas mediante la inmunogammagrafía. Estos fueron poco a poco sustituidos por moléculas con mejores prestaciones como los péptidos y la 18F-fluordesoxiglucosa (18F-FDG). No obstante, en el presente siglo, la amplia introducción de la inmunoterapia produjo un cambio de paradigma en cuanto al empleo de los anticuerpos monoclonales radiomarcados para la adecuada selección y seguimiento de los pacientes a ser tratados con inmunoterapia, resurgiendo la inmunotomografía por emisión de fótón único (inmuno-SPECT), la inmunotomografía por emisión de positrones (inmuno-PET) y la imagen corregistrada con la tomografía axial computarizada (TAC), como modalidades de gran valor en el manejo del cáncer. El objetivo del presente trabajo fue brindar una panorámica acerca de la evolución de la imagen nuclear con anticuerpos monoclonales radiomarcados y sus principales aplicaciones en el tiempo, fundamentalmente en el estudio de los pacientes con cáncer.
Abstract In the beginning, radionuclide-labeled monoclonal antibodies were widely employed for the study of various diseases, mainly oncological, by immunoscintigraphy. They were gradually replaced by molecules with better performance such as peptides and 18F-FDG. However, in the present century, the wide introduction of immunotherapy produced a paradigm shift in the use of radiolabeled monoclonal antibodies for the proper selection and follow-up of patients to be treated with immunotherapy, re-emerging of the immune-single photon emission tomography (immuno-SPECT), the immune-positron emission tomography (immuno-PET) and the co-registered image with computed tomography (CT) as imaging modalities of great value in the management of cancer. The aim of the present work was to provide an overview of the evolution of nuclear imaging with radiolabeled monoclonal antibodies and their main applications over the time, mainly in the study of patients with cancer.
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RESUMEN En los marcos de la estrecha colaboración entre la Agencia de Energía Nuclear y Tecnologías de Avanzada y el Ministerio de Salud Pública, a inicios de este siglo se procedió a organizar, en el Centro de Isótopos, un servicio de determinación de hormonas por metodologías nucleares, atendiendo a necesidades de diversas instalaciones hospitalarias. El centro disponía de personal capacitado en técnicas de radioinmunoanálisis y seguridad radiológica, el equipamiento necesario y laboratorios licenciados para el trabajo con sustancias radiactivas. Para ello se hizo necesario incorporar al Sistema de Calidad las regulaciones vigentes para laboratorios clínicos y adecuar la infraestructura para el procesamiento de no menos de 1000 muestras por semana, procedentes de 16 hospitales. Se requería recogida y transportación de las muestras, recepción, inspección y registro, análisis, evaluación y entrega de los resultados. En función de la actividad se diseñó y puso en operación un sistema informático y se normalizaron acciones para asegurar competencia técnica avalada por: trazabilidad; incertidumbre; ejercicios de aptitud y otros requisitos exigidos por la regulación de Buenas Prácticas de Laboratorio Clínico vigentes en el país. A raíz de nuevas regulaciones, el servicio ha introducido de manera paulatina determinadas mejoras. En 15 años de trabajo este laboratorio ha resultado el principal del país en emplear métodos radiactivos para la cuantificación de hormonas, lo que favorece la atención de más de 70 000 pacientes como promedio al año, principalmente de la capital. Esto es parte de nuestra contribución en el 500 aniversario de La Habana.
ABSTRACT Within the framework of the close collaboration between the Agency of Nuclear Energy and Advanced Technologies and the Ministry of Public Health, at the beginning of this century, and considering the need of different hospitals, the Center of Isotopes (CENTIS), began providing service to determine hormones by nuclear methodologies,. CENTIS had qualified personnel in immune radioanalysis RIA/IRMA techniques and radiation safety, in addition to having the required equipment and accredited laboratories to work with radioactive substances. As a result, it was necessary to incorporate to CENTIS Quality System, the regulations in force for clinical laboratories , and to adapt its infrastructure for the processing of no less than 1000 samples per week from 16 hospitals. The Service required collection and transportation of the samples, reception, inspection and registration, test, evaluation and delivery of the test results. In order to fulfil this activity, a computer system was designed and set , and standards for actions were established to guarantee a high technical quality endorsed by traceability, uncertainty; proficiency tests and other requirements demanded by the Good Practices of Clinical Laboratory (BPLC 03 -2009) issued by CECMED. Due to new regulations, several improvements have been introduced. In 15 years, CENTIS laboratory has become the most important in the country using radioactive methods for the quantification of hormones, with an average testing of more than 70 000 patients per year, mainly in the capital. This is part of our contribution in the 500th Anniversary of Havana.
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Objective • To investigate the characteristics and clinical application value of anti-double stranded DNA (dsDNA) antibody detected by enzyme-linked immunosorbent assay (ELISA). Methods • 186 patients with systemic lupus erythematosus, 183 autoimmune disease of non-SLE controls, 78 non-autoimmune disease controls and 50 healthy controls were selected. The serum anti-dsDNA antibody was detected simultaneously by the methods of ELISA and radioimmunoassay (RIA) and their diagnostic efficacies for detection were compared. Results • The sensitivities of anti-dsDNA antibody in SLE by RIA and ELISA were 47.31% and 62.90%, respectively. The specificities were 85.85% and 81.67%, respectively. The positive predictive were 66.67% and 67.24%, respectively. The negative predictive were 73.15% and 78.14%, respectively. The anti-dsDNA antibody levels of SLE patients detected by ELISA and RIA both increased with the increase of SLE disease activity index. Conclusion • The specificity of ELISA is similar with RIA in diagnosing SLE, and the sensitivity is higher than RIA, which can screen the patients with SLE. In addition, the two methods are both suitable for monitoring the condition of SLE.
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Aldosterone is a steroid hormone that acts on the kidneys to maintain the balance of sodium and water. Primary hyperaldosteronism (PA) is the most common disease that causes secretory hypertension. PA is often unrecognized and is associated with a high death rate. The aldosterone/rein rate (ARR) and detection of serum or urinary aldosterone are the most effective method to screen and identify PA. In healthy individuals, aldosterone concentration is present in low quantities in serum and there are numerous compounds that can potentially interfere with analysis making aldosterone a technically challenging analyte quantifying method. At present, the method of aldosterone detection includes radioimmunoassay, enzyme-linked immunosorbent assay, chemiluminescence method and mass spectrometry. These methods have their own advantages and disadvantages, the ARR ratios of different detection methods for the diagnosis of PA are not completely consistent. In this paper, the detection methods and clinical applications of aldosterone are reviewed.
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Objective@#To evaluate the consistency of different methods for detecting aldosterone concentration in blood and to establish a reference interval of serum aldosterone concentration by liquid chromatography-tandem mass spectrometry(LC-MS/MS).@*Methods@#Concentrations of blood aldosterone were measured by LC-MS/MS, chemiluminescent assays (Diasorin, Domestic A and B systems) and radioimmunoassay (RIA) in 138 healthy adults, 67 patients with essential hypertension and 23 patients with primary aldosteronism.@*Results@#Aldosterone concentrations measured by various methods were quiet different(P<0.01). Spearman correlation analysis showed that the correlation coefficient were 0.776(P<0.01) between CLIA (Diasorin) and LC-MS/MS, 0.805(P<0.01) between CLIA (Domestic A) and LC-MS/MS, 0.058(P>0.05) between CLIA(Domestic B) and LC-MS/MS, 0.338(P<0.01) as well as between RIA and LC-MS/MS. Bland-Altman analysis for the measurements showed poor consistency among methods for aldosterone concentrations. The reference interval was 15.2-222.2 pg/ml for serum aldosterone concentrations by LC-MS/MS.@*Conclusions@#There are significant differences of blood aldosterone concentrations determined by different methods. Clinically, a specified reference interval might be needed while using different methods.
ABSTRACT
Aldosterone is a steroid hormone that acts on the kidneys to maintain the balance of sodium and water. Primary hyperaldosteronism (PA) is the most common disease that causes secretory hypertension. PA is often unrecognized and is associated with a high death rate. The aldosterone/rein rate (ARR) and detection of serum or urinary aldosterone are the most effective method to screen and identify PA. In healthy individuals, aldosterone concentration is present in low quantities in serum and there are numerous compounds that can potentially interfere with analysis making aldosterone a technically challenging analyte quantifying method. At present, the method of aldosterone detection includes radioimmunoassay, enzyme-linked immunosorbent assay, chemiluminescence method and mass spectrometry. These methods have their own advantages and disadvantages, the ARR ratios of different detection methods for the diagnosis of PA are not completely consistent. In this paper, the detection methods and clinical applications of aldosterone are reviewed.
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PURPOSE: In radioimmunoassay (RIA), the gamma counter is the important instrument for the accurate measurement. To manage quality assurance of RIA, the counting efficiency of gamma counter is one of the important parameters. The aimof this study was to evaluate the counting efficiency of gamma counters in multiple institutes on the base of traceability by using the certified reference materials (CRMs).METHODS: Twenty-three institutes that perform RIA were enrolled in this study. I-125 CRMs that were certified by National Institute of Standards and Technology (NIST) were used. Each institute was asked to count the activity of I-125 CRMs at most twice on all gamma counters in use. The counting efficiency of each well of counter was calculated on the base of NIST-certified information, corrected for I-125 decay for date of testing.RESULTS: From 23 institutes, 44 gamma counters were evaluated. The average counting efficiency of all wells was 85.9% and the standard deviation was 13.5%. As a mean value of each gamma counter, three gamma counters showed poor counting efficiency (less than 70%). The poorest counting efficiency was 7%. The counting efficiency of seven gamma counters was between 70 and 75%. Eight counters had the counting efficiency between 75 and 90%. More than half of counter (26 gamma counters) showed excellent counting efficiency (more than 90%). The standard deviation variation range of inter-well efficiency was from 0 to 11.2.CONCLUSION: The first survey on the counting efficiency of gamma counter was performed in South Korea. Most of the RIA laboratories have well managed the quality assurance of gamma counter.
Subject(s)
Academies and Institutes , Immunoradiometric Assay , Korea , Quality Control , RadioimmunoassayABSTRACT
Quantitative immunoassay technique is the common method of quantitative detection in clinical laboratory. Several important branches of quantitative immunoassay were formed by changing the tracer or the Antigen-antibody complex separation method, including radioimmunoassay, fluorescent immunoassay, enzyme immunoassay, chemiluminescence, colloidal gold, immuno-turbidimetric analysis and homogeneous immunoassay. Different immunoassay techniques have their own characteristics, also apply to different detecting conditions in clinic. This paper reviewed several common kinds of quantitative immunoassay technology, and discussed both their advantages and disadvantages, which provide reference for the application and development of clinical testing technology.
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In this study, four crab-eating fox females (Cerdocyon thous) maintained at the Federal University of Mato Grosso Zoo, Cuiabá, Brazil, were investigated for 12 months, using feces measurement of estradiol and progesterone concentrations. Fecal collections were performed three times a week for hormone extraction. Two methods of analysis, Elisa (EIA) and Radioimmunoassay (RIA), were used in the measurement of progesterone (P4) and estradiol (E2) metabolites. The aim of this study was to compare and validate two different methods of hormone measurement for C. thous. There were no differences regarding the method used. The Radioimmunoassay technique proved to be more sensitive, however, both showed similar results.(AU)
Neste estudo, quatro fêmeas de cachorros-do-mato (Cerdocyon thous) mantidas no Zoológico da Universidade Federal de Mato Grosso, Cuiabá, MT, Brasil, foram investigadas pelo período de 12 meses, mediante a mensuração de concentrações de estradiol e progesterona em fezes. Coletas de fezes foram realizadas três vezes por semana para posterior extração hormonal. Dois métodos de análise de metabólitos fecais, elisaimunoensaio (EIA) e radioimunoensaio (RIA), foram utilizados na mensuração dos metabólitos de progesterona (P4) e estradiol (E2). O objetivo deste estudo foi comparar e validar dois diferentes métodos de mensuração hormonal para C. thous. Não houve diferença significativa com relação ao método empregado. A técnica de radioimunoensaio demonstrou ser mais sensível, no entanto ambas apresentaram resultados semelhantes.(AU)
Subject(s)
Animals , Canidae , Estradiol/analysis , Feces , Metabolism , Progesterone , Biomarkers/metabolismABSTRACT
BACKGROUND: Thyroglobulin (Tg) is the primary biochemical marker used to monitor patients with differentiated thyroid cancer (DTC) for residual or recurrent disease after total thyroidectomy, as only normal or well-differentiated malignant thyroid cells produce Tg. Here, we evaluated the precision and functional sensitivity (FS) of a recently developed highly sensitive Tg (hsTg) electrochemiluminescent immunoassay (ECLIA) and compared it to that of the radioimmunoassay (RIA) method using pooled human serum with low levels of Tg. METHODS: For the ECLIA method, the Elecsys Tg II kit (Roche Diagnostics, Germany) was used with an E170 analyzer (Roche Diagnostics). For the RIA method, the Tg-plus-RIA kit (BRAHAMS, Germany) was used with a Cobra Quantum gamma counter (Packard Instrument Company, USA). The precision and limit of detection (LOD) were determined according to the Clinical and Laboratory Standards Institute (CLSI) guidelines. FS was determined using a modification of the CLSI guideline. RESULTS: The total precision of the hsTg ECLIA and RIA methods was 9.6% and 48.2%, respectively. The manufacturer-reported LOD was verified by the hsTg ECLIA (0.04 ng/mL), but not by the RIA method (>0.08 ng/mL). The hsTg ECLIA showed better FS (0.04 ng/mL at a coefficient of variation [CV] of 10%) than the RIA method (0.37 ng/mL at a CV of 20%). CONCLUSIONS: Thus, the hsTg ECLIA performed better than the RIA method in terms of FS, which is extremely important for the early detection of residual or recurrent disease in DTC patients after total thyroidectomy. The excellent performance of the hsTg ECLIA could allow for clinical Tg measurement without thyroid-stimulating hormone stimulation, in contrast to the insufficient performance of the RIA method.