Anticuerpos anti-estreptavidina: Confusión diagnóstica por interferencia bioquímica / Anti-estreptavidin antibodies. Diagnostic confusion by biochemical interference

Se presenta el caso de una paciente que, durante los estudios por búsqueda de fertilidad y posterior embarazo, mostraba un perfil tiroideo alterado con niveles elevados de T4 libre y TSH normal. Luego de descartar un adenoma tirotropo y ante la ausencia de sintomatología clínica de hipertiroidismo, se investigó la posibilidad de interferencias analíticas en los inmunoensayos utilizados para la medición de las hormonas. Se han descrito interferencias causadas por anticuerpos heterófilos, macro TSH, anticuerpos anti-tiroideos, biotina, y en menor medida anticuerpos anti-estreptavidina y anti-rutenio. Los análisis de la paciente se realizaron en autoanalizador cuya plataforma emplea el sistema estreptavidina-biotina que es muy susceptible a varios interferentes. Un algoritmo propuesto incluye una serie de pruebas simples de realizar e interpretar que permiten detectar o descartar la presencia de interferentes. De acuerdo al mismo, se efectuó la comparación con una plataforma analítica diferente (que no utiliza el sistema estreptavidina-biotina), diluciones seriadas, precipitación con polietilenglicol 6000 y tratamiento con micropartículas recubiertas con estreptavidina. Los resultados obtenidos confirmaron la presencia de anticuerpos anti-estreptavidina en el suero de la paciente. Ante discordancias entre las manifestaciones clínicas y los resultados de laboratorio, se debe investigar la posibilidad de interferencias metodológicas para evitar el riesgo iatrogénico potencial que implica una interpretación bioquímica errónea.

We present the case of a patient who, during studies for fertility and subsequent pregnancy, showed an altered thyroid profile with elevated levels of free T4 and normal TSH. After ruling out a thyrotropic adenoma and in the absence of clinical symptoms of hyperthyroidism, the possibility of analytical interference in the immunoassays used to measure hormones was investigated. Interferences caused by heterophile antibodies, macro TSH, anti-thyroid antibodies, biotin, and to a lesser extent anti-streptavidin and anti-ruthenium antibodies have been described. The analysis of the patient was carried out in a self-analyzer whose platform uses the streptavidin-biotin system that is very susceptible to several interferents. A proposed algorithm includes a series of simple tests to perform and interpret that allow detecting or ruling out the presence of interferents. Accordingly, a comparison was made with a different analytical platform (which does not use the streptavidin-biotin system), serial dilutions, precipitation with polyethylene glycol 6000 and treatment with microparticles coated with streptavidin. Results obtained confirmed the presence of anti-streptavidin antibodies in the patient's serum. In the case of disagreements between clinical manifestations and laboratory results, the possibility of methodological interferences should be investigated in order to avoid the potential iatrogenic risk involved in an erroneous biochemical interpretation.

Inmunoexpresión p53, sangre oculta en heces de pacientes colecistectomizados y colelitiasis con adenomas colónicos / P53 Immunoexpression, Faecal Occult Blood from Cholecystectomized Patients and Cholelithiasis with Colonic Adenomas

Introducción: la secuencia adenoma- adenocarcinoma, es resultado de fallos genéticos en las células intestinales heredados o adquiridos. Objetivo: determinar la posible relación entre la inmunoexpresión de la p53 y la positividad de la sangre oculta en heces en los adenomas de colon con alto grado de displasia diagnosticados en pacientes colecistectomizados o con colelitiasis. Métodos: se realizó un estudio descriptivo, de corte transversal, en el Instituto de Gastroenterología, en el período de mayo de 2013 hasta junio de 2015. Se realizaron pruebas estadísticas descriptiva y de chi Cuadrado y probabilidad exacta de Fisher. Resultados: la proporción de adenomas con alto grado de displasia fue similar en pacientes colecistectomizados y con colelitiasis (50 por ciento) respectivamente. Una alta proporción se diagnosticó en colecistectomizados femeninas (35 por ciento), con 60 y más años de edad (53 por ciento) y 11 y más años de colecistectomizados (60 por ciento), mientras que en las colelitiasis fueron masculinos (30 por ciento). Conclusiones: una alta proporción de adenomas con alto grado de displasia presentan inmunoexpresión de la p53 y sangre en heces positiva en pacientes colecistectomizados y con colelitiasis, que se reporta por vez primera(AU)

Introduction: The adenoma - adenocarcinoma sequence is a result of inherited or acquired genetic failures in the intestinal cells. Objective: To determine the immunohistochemical expression of p53 and the positivity of the fecal occult blood test in colon adenomas with high degree of diagnosed dysplasia in cholecystectomized patients or with cholelithiasis. Methods: Descriptive, cross-sectional study conducted in the Institute of Gastroenterology in the period of May, 2013 to June, 2015. Statistical tests were statistics testing, exact Chi Square and Fisher's probability tests. Results: The proportion of adenomas with high degree of dysplasia was similar in cholecystectomized patientsand with cholelithiasis (50 percent) respectively. A high proportion diagnosed in colecistectomizados women (35 percent), 60 and more years of age (53 percent) and 11 and more years of performed cholecystectomy (60 percent), whereas cholelithiasis prevailed in males (30 percent). Conclusions: High proportion of adenomas with high degree of dysplasia present p 53 immunoexpression and positive fecal occult blood test in cholecystectomized patients and patients with cholelithiasis that is reported for the first time(AU)

Estudo imunoistoquímico de componentes da Via Sonic Hedgehog, Stat3 e Mcm3 em tumores de glândula salivar / Immunohistochemical study components of Via Sonic Hedgehog, Stat3 and MCM3 in salivary gland tumors

O adenoma pleomórfico (AP), o carcinoma mucoepidermóide (CME) e o carcinoma adenóide cístico (CAC) representam tumores frequentes em glândula salivar. A via de sinalização Sonic Hedgehog (Hh) e o Transdutor de sinal e ativador da transcrição 3 (STAT3) desempenham funções importantes na proliferação celular, favorecendo o desenvolvimento tumoral e a proteína MCM3 tem sido considerada uma nova classe de marcadores de proliferação celular. Portanto, o presente trabalho propõe-se a estudar componentes da via Hh, bem como o STAT3 e o MCM3 em neoplasias de glândula salivar, na tentativa de adicionar informações sobre as características biológicas dessas neoplasias. Foram utilizados 9 casos de AP, 17 casos de CAC e 20 casos de CME e, por meio da técnica imunoistoquímica, realizou-se a detecção das seguintes proteínas: SHH, GLI1, SUFU, HHIP, STAT3 e MCM3. No AP, observou-se alta expressão citoplasmática de SHH e SUFU, e baixa expressão de STAT3 e MCM3. No CAC, observou-se alta expressão de GLI1, HHIP e STAT3 e baixa expressão de SHH, SUFU e MCM3. No CME, observou-se alta expressão de SHH, GLI1, SUFU e HHIP e baixa expressão de STAT3 e MCM3. Quando comparado entre os tipos tumorais, observou-se diferença estatisticamente significante para expressão de SHH (p=0.0064), STAT3 (p=0.0003) e MCM3 (p=0.0257)...

The pleomorphic adenoma (PA), mucoepidermoid carcinoma (MEC) and the adenoid cystic carcinoma (ACC) are common tumors arising from salivary glands. The Sonic Hedgehog signaling pathway (Hh) and signal transducer and activator of transcription 3 (STAT3) play important roles in cell proliferation, favoring tumor growth. The MCM3 protein has been considered as a novel class of cell proliferation markers. The aim of this investigation was to study components of the Hh pathway, as well as STAT3 and MCM3 in salivary gland neoplasms in an attempt to add information about the biological characteristics of these neoplasms. We used 9 cases of PA, 17 cases of ACC and 20 cases of MEC. Using immunohistochemistry, were investigated: SHH, GLI1, Sufu, HHIP, STAT3 and MCM3. In PA, there was high expression of cytoplasmic SHH and Sufu, and low expression of STAT3 and MCM3. In the ACC, there was high expression of GLI1, HHIP and STAT3 and low expression of SHH, SUFU and MCM3. In the MEC, we observed high expression of SHH, GLI1, SUFU and HHIP and low expression of STAT3 and MCM3. There was a statistically significant difference between SHH (p=0.0064), STAT3 (p=0.0003) and MCM3 (p=0.0257) when all tumors were compared...

Plurihormonal secretion in pituitary adenomas: immunohistological study of 100 cases

Background and Pituitary adenomas show wide variability in morphology and function. The aim of this study is to find out the hormonal secretion in these adenomas, as plurihormonality might have a relationship with tumor development. Material and Histopathological and immunohistological studies were done on 100 consecutive pituitary adenomas removed by transsphenoidal resection in the university hospitals of Damascus University, to reveal the secretion of five pituitary hormones: PRL, GH, LH ACTH, and TSH, over a period of 27 months, between 2000-2002. Adenomas had equal incidence in males and females [50M, aged 6-60y and 50 females, aged 10-64y]. The mostly observed adenomas were PRL-secreting adenoma in males [15 cases=30% of adenomas in males], and GH-PRL-secreting adenoma in females [16 cases=32% of adenomas in females]. There was monohormonal secretion in 37% of adenomas, bihormonal secretion in 43% of adenomas, and plurihormonal secretion in 18% of adenomas. Traces of hormonal secretion were found in 92% of the nonsecreting adenomas. In 2% of adenomas, no secretion could be detected. The study showed that plurihormonality is common in pituitary adenomas. As most of these pituitary adenomas were benign, it suggests that there is no relationship between plurihormonality and aggressiveness

Expresión inmunohistoquímica de la oncoproteína p53 en adenomas y adenocarcinomas del intestino grueso / Immunohistochemical expression of p53 oncoprotein in large bowel adenomas ans carcinomas

Material and methods: A random sample of 28 large bowel adenomas and 44 carcinomas was studied. Determination of p53 protein was made with an immunohistochemical method using monoclonal antibodies. Patients were followed for a mean of 36 months (range 1 to 100 months). Results: p53 immunostaining was obtained in one adenoma (3.5 percent) and in 18 carcinomas (41 percent, p = 0.01). There were no differences in survival during follow up, between cancer patients that expressed or did not express p53 protein. Conclusions: About half of colorectal tumors have immunohistochemical expression of p53 protein, as published abroad. We did not find a prognostic value for this protein in our sample

Macroadenomas näo-funcionantes da hipófise: estudo imuno-histoquímico / Functionless pituitary macroadenomas: immunohistochemical study

Cinqüenta e nove adenomas hipofisários, do tipo nao-funcionante, foram analisados pelo método imuno-histoquímico. Os tumores foram estudados através da técnica da peroxidase - avidina - biotina (ABC) e pesquisados os seguintes hormônios, com anticorpos primários específicos: prolactina (PRL), hormônio do crescimento (HS), corticotrofina (ACTH), gonadotrofinas (HCG) e tireotrofina (TSH). Trinta e oito tumores nao reagiram a nenhum anticorpo, 8 tumores apresentaram imunorreaçao positiva à prolactina, 5 tumores eram imunorreativos ao HS, 6 eram imunorreativos ao ACTH, e 10 tumores eram imunorreativos às gonadrotofinas, sendo que 5 ao LH e 5 ao FSH. Dos tumores que apresentaram imunorreatividade ao hormônio do crescimento e à prolactina houve manifestaçao clínica em apenas um, cujo paciente evoluiu com altas taxas de prolactina sangüínea.

Prognostic significance of proliferating cell nuclear antigen-positive growth fraction in gastric adenomas

The proliferative activity of gastric adenomas from 18 patients (42 endoscopic procedures) was compared with follow-up results. These cases were gastric adenomas proven by follow-up with repeated endoscopic procedures for more than 2 years, or were confirmed as gastric adenocarcinoma thereafter by histopathologic examination. Among the eighteen cases, nine showed carcinoma in the subsequent biopsies (group 1) and the remaining nine did not result in carcinoma (group 2). The proliferating cell nuclear antigen (PCNA) positivity rates of the two groups were significantly different (P < 0.01). The average PCNA positivity in group 1 was 33.1%, while it was 10.0% in group 2. The risk of developing carcinoma increased as the PCNA positivity increased: 0% in the low PCNA positivity group, 41% in the mid-positivity group and 89% in the high positivity group. We concluded that growth fraction could be taken into account as one of the most important prognostic factors for gastric adenoma, and accordingly repeated endoscopic biopsies with close follow-up should be carried out especially in the high PCNA positivity group.

Imuno-histoquímica hipofisária: metodologia e aplicaçäo / Immunohistochemistry of the pituitary gland: methodology and use

Os autores estudaram a aplicaçäo do método da peroxidase-antiperoxidase para detectar hormônio de crescimento (GH), prolactina (PRL) e corticotrofina (ACTH) em cortes de tecidos normais e de pituitária adenomatosa utilizando anticorpos de radioimunoensaio (RIA). Quatro glândulas pituitárias normais obtidas em autópsia e 21 adenomas pituitárias normais obtidos durante cirurgia de pacientes com acromegalia (16), hiperprolactinemia (2) e doença de Cushing (3) foram estudados. Anti-soros obtidos de carneiros imunizados com preparaçöes altamente purificadas de GH humano, prolactina ovina e ACTH porcino. Reatividades cruzadas de anti-GH com PRL, anti-PRL com GH e anti-ACTH 1-39 com ACTH 1-24 e ACTH 18-39 no RIA foram: 0,6%, 0,03%, 3,1% e 5,7% respectivamente. Detecçäo de cada hormônio foi bem sucedida em todos os cortes estudados de tecido pituitário normal. Melhores colaboraçöes foram obtidas usando diluiçöes primárias do anti-soro mais baixas que aquela rotineiramente empregadas em RIA. Anti-GH mostrou näo ter reatividade cruzada significante com PRL em cortes de tecido pituitário. Anti-PRL, contudo, mostrou alguma reatividade cruzada com GH, mas isto pôde ser evitado por absorçäo prévia do anti-soro com GH. Nenhuma diferença na coloraçäo pôde ser detectada fosse usado ou näo o anti-ACTH depois da imuno-absorçäo com ACTH 1-24. Todos os adenomas pituitários de pacientes acromegálicos mostraram células imunorreativas para GH, porém poucos adenomas tiveram todas ou mesmo a maioria das células positivas para GH. Todos os adenomas obtidos de pacientes com hiperprolactinemia e doença de Cushing coraram-se com anti-soro contra PRL e ACTH, respectivamente. Estes resultados validam o uso dos anti-soros mencionados na imuno-histoquímica da pituitária

Estudios inmunohistoquímicos en lesiones foliculares tiroideas: demostración de tiroglobulina y tiroxina / Immunohistochemical studies of thy roid follicular lesions: thyroxine and thyroglobulin localization demonstration

Se ha estudiado con el método de peroxidasa-antiperoxidasa la presencia y distribución de tiroglobulina y tiroxina en una serie de 38 muestras de lesiones tiroideas y extratiroideas. Las muestras tiroideas estudiadas correspondían a glandulas normales, lesiones no tumorales, adenomas y carcinomas. Con tiroglobulina fueron positivos el 93% de las lesiones de origen tiroideo incluyendo todas las tiroides normales y lesiones no tumorales, 3 de los 4 adenomas, los 8 carcinomas foliculares y 9 de los 10 carcinomas papilares. Los 6 carcinomas papilares no tiroideos y una metástasis tiroidea de origen mamario fueron negativos. Con tiroxina la tinción fue menos constante e intensa. Sólo se tiñeron el 53% de las lesiones tiroideas incluyendo 1 de 3 tiroides normales, 3 de 4 lesiones no tomorales, 1 de 4 adenomas foliculares, los 3 carcinomas foliculares y 1 de 3 carcinomas papilares. Esta serie y otros trabajos en la literatura demuestran que la tiroglobulina es un excelente marcador de lesiones foliculares tiroideas siendo de utilidad diagnóstica en carcinomas pobremente diferenciados y lesiones metastásicas de posible origen tiroideo. La demonstración de tiroxina si bien es útil como la anterior para determinar el estado funcional de la célula tiroidea es de evidente menor valor diagnóstico