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1.
Comput Biol Med ; 172: 108167, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38461699

RESUMEN

In recent decades, many studies have been published on the use of automatic smear microscopy for diagnosing pulmonary tuberculosis (TB). Most of them deal with a preliminary step of the diagnosis, the bacilli detection, whereas sputum smear microscopy for diagnosis of pulmonary TB comprises detecting and reporting the number of bacilli found in at least 100 microscopic fields, according to the 5 grading scales (negative, scanty, 1+, 2+ and 3+) endorsed by the World Health Organization (WHO). Pulmonary TB diagnosis in bright-field smear microscopy, however, depends upon the attention of a trained and motivated technician, while the automated TB diagnosis requires little or no interpretation by a technician. As far as we know, this work proposes the first automatic method for pulmonary TB diagnosis in bright-field smear microscopy, according to the WHO recommendations. The proposed method comprises a semantic segmentation step, using a deep neural network, followed by a filtering step aiming to reduce the number of false positives (false bacilli): color and shape filtering. In semantic segmentation, different configurations of encoders are evaluated, using depth-wise separable convolution layers and channel attention mechanism. The proposed method was evaluated with a large, robust, and annotated image dataset designed for this purpose, consisting of 250 testing sets, 50 sets for each of the 5 TB diagnostic classes. The following performance metrics were obtained for automatic pulmonary TB diagnosis by smear microscopy: mean precision of 0.894, mean recall of 0.896, and mean F1-score of 0.895.


Asunto(s)
Mycobacterium tuberculosis , Tuberculosis Pulmonar , Humanos , Microscopía/métodos , Tuberculosis Pulmonar/diagnóstico por imagen , Redes Neurales de la Computación , Sensibilidad y Especificidad
2.
J Pathol ; 262(3): 271-288, 2024 03.
Artículo en Inglés | MEDLINE | ID: mdl-38230434

RESUMEN

Recent advances in the field of immuno-oncology have brought transformative changes in the management of cancer patients. The immune profile of tumours has been found to have key value in predicting disease prognosis and treatment response in various cancers. Multiplex immunohistochemistry and immunofluorescence have emerged as potent tools for the simultaneous detection of multiple protein biomarkers in a single tissue section, thereby expanding opportunities for molecular and immune profiling while preserving tissue samples. By establishing the phenotype of individual tumour cells when distributed within a mixed cell population, the identification of clinically relevant biomarkers with high-throughput multiplex immunophenotyping of tumour samples has great potential to guide appropriate treatment choices. Moreover, the emergence of novel multi-marker imaging approaches can now provide unprecedented insights into the tumour microenvironment, including the potential interplay between various cell types. However, there are significant challenges to widespread integration of these technologies in daily research and clinical practice. This review addresses the challenges and potential solutions within a structured framework of action from a regulatory and clinical trial perspective. New developments within the field of immunophenotyping using multiplexed tissue imaging platforms and associated digital pathology are also described, with a specific focus on translational implications across different subtypes of cancer. © 2024 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.


Asunto(s)
Neoplasias de la Mama , Humanos , Femenino , Biomarcadores de Tumor/genética , Pronóstico , Fenotipo , Reino Unido , Microambiente Tumoral
3.
J Pathol ; 260(5): 514-532, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37608771

RESUMEN

Modern histologic imaging platforms coupled with machine learning methods have provided new opportunities to map the spatial distribution of immune cells in the tumor microenvironment. However, there exists no standardized method for describing or analyzing spatial immune cell data, and most reported spatial analyses are rudimentary. In this review, we provide an overview of two approaches for reporting and analyzing spatial data (raster versus vector-based). We then provide a compendium of spatial immune cell metrics that have been reported in the literature, summarizing prognostic associations in the context of a variety of cancers. We conclude by discussing two well-described clinical biomarkers, the breast cancer stromal tumor infiltrating lymphocytes score and the colon cancer Immunoscore, and describe investigative opportunities to improve clinical utility of these spatial biomarkers. © 2023 The Pathological Society of Great Britain and Ireland.


Asunto(s)
Neoplasias del Colon , Humanos , Biomarcadores , Benchmarking , Linfocitos Infiltrantes de Tumor , Análisis Espacial , Microambiente Tumoral
4.
J Pathol ; 260(5): 498-513, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37608772

RESUMEN

The clinical significance of the tumor-immune interaction in breast cancer is now established, and tumor-infiltrating lymphocytes (TILs) have emerged as predictive and prognostic biomarkers for patients with triple-negative (estrogen receptor, progesterone receptor, and HER2-negative) breast cancer and HER2-positive breast cancer. How computational assessments of TILs might complement manual TIL assessment in trial and daily practices is currently debated. Recent efforts to use machine learning (ML) to automatically evaluate TILs have shown promising results. We review state-of-the-art approaches and identify pitfalls and challenges of automated TIL evaluation by studying the root cause of ML discordances in comparison to manual TIL quantification. We categorize our findings into four main topics: (1) technical slide issues, (2) ML and image analysis aspects, (3) data challenges, and (4) validation issues. The main reason for discordant assessments is the inclusion of false-positive areas or cells identified by performance on certain tissue patterns or design choices in the computational implementation. To aid the adoption of ML for TIL assessment, we provide an in-depth discussion of ML and image analysis, including validation issues that need to be considered before reliable computational reporting of TILs can be incorporated into the trial and routine clinical management of patients with triple-negative breast cancer. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.


Asunto(s)
Neoplasias Mamarias Animales , Neoplasias de la Mama Triple Negativas , Humanos , Animales , Linfocitos Infiltrantes de Tumor , Biomarcadores , Aprendizaje Automático
5.
NPJ Breast Cancer ; 7(1): 150, 2021 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-34853355

RESUMEN

The advent of immune-checkpoint inhibitors (ICI) in modern oncology has significantly improved survival in several cancer settings. A subgroup of women with breast cancer (BC) has immunogenic infiltration of lymphocytes with expression of programmed death-ligand 1 (PD-L1). These patients may potentially benefit from ICI targeting the programmed death 1 (PD-1)/PD-L1 signaling axis. The use of tumor-infiltrating lymphocytes (TILs) as predictive and prognostic biomarkers has been under intense examination. Emerging data suggest that TILs are associated with response to both cytotoxic treatments and immunotherapy, particularly for patients with triple-negative BC. In this review from The International Immuno-Oncology Biomarker Working Group, we discuss (a) the biological understanding of TILs, (b) their analytical and clinical validity and efforts toward the clinical utility in BC, and (c) the current status of PD-L1 and TIL testing across different continents, including experiences from low-to-middle-income countries, incorporating also the view of a patient advocate. This information will help set the stage for future approaches to optimize the understanding and clinical utilization of TIL analysis in patients with BC.

8.
Artículo en Portugués | LILACS | ID: biblio-1359461

RESUMEN

RESUMO: A resposta inflamatória sistêmica e o déficit nutricional são características frequentes nos pacientes com câncer e o escore prognóstico de Glasgow tem se mostrado excelente valor prognóstico no câncer gastresofágico e ferramenta validada na avaliação clínica de pacientes com câncer. Assim, o presente estudo teve como objetivo analisar a associação do escore prognóstico de Glasgow com sobrevida de pacientes portadores de carcinoma gástrico, através de revisão sistemática e meta-análise. Foi seguida a metodologia Preferred Reporting Items for Systematic Reviews and Meta-Analyses-PRISMA, com pesquisa nas plataformas Medline, Web of Science e SCOPUS, utilizando descritores apropriados. Foram incluídos estudos clínicos e observacionais, publicados antes de 30.09.2017 e sem restrição de linguagem. Os critérios de inclusão foram a utilização do escore prognóstico de Glasgow como fator prognóstico em pacientes portadores de diagnóstico histológico de carcinoma gástrico; com idade superior a 18 anos; submetidos à quimioterapia, radioterapia ou cirurgia; com dosagem de Proteína C Reativa e albumina no pré-tratamento; e com dados referentes à sobrevida durante o estudo. A qualidade dos estudos foi avaliada com a Escala de Newcastle-Ottawa e o risco de viés com ferramenta da Cochrane Collaboration. Hazard-Ratio e Intervalo de Confiança de 95% foram extraídos dos estudos, e a significância estatística definida como p<0,05. Foram identificados 255 artigos, e por fim, analisados 15 estudos. A análise apresentou o escore prognóstico de Glasgow como fator de risco relacionado à sobrevida e considerado marcador prognóstico independente quando relacionado à sobrevida global dos pacientes com câncer gástrico que realizaram cirurgia e quimioterapia. (AU)


ABSTRACT: The systemic inflammatory response and nutritional deficit are frequent features in cancer patients, and the Glasgow prognostic score has shown to be an excellent prognostic value in gastroesophageal cancer and a validated tool in the clinical evaluation of cancer patients. Thus, the present study aimed to analyze the association of Glasgow's prognostic score with the survival of patients with gastric carcinoma through systematic review and meta-analysis. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses-PRISMA methodology was considered, with research on the Medline, Web of Science, and SCOPUS platforms, using appropriate descriptors. Clinical and observational studies published before September 30, 2017, and without language restriction were included. Inclusion criteria were the use of Glasgow prognostic score as a prognostic factor in patients with histological diagnosis of gastric carcinoma; over the age of 18; undergoing chemotherapy, radiation or surgery; with dosages of Reactive Protein C and albumin in the pre-treatment; and with data regarding survival during the study. The quality of the studies was assessed using the Newcastle-Ottawa Scale and the risk of bias using the Cochrane Collaboration tool. Hazard-Ratio and 95% Confidence Interval were extracted from the studies, with statistical significance defined as p <0.05. Two hundred fifty-five articles were identified, and finally, 15 studies were analyzed. The analysis presented Glasgow prognostic score as a risk factor related with survival and considered an independent prognostic marker when related to the overall survival of patients with gastric cancer who underwent surgery and chemotherapy. (AU)


Asunto(s)
Humanos , Complicaciones Posoperatorias , Pronóstico , Neoplasias Gástricas , Sobrevida , Metaanálisis , Escala de Consecuencias de Glasgow
9.
Rev Lat Am Enfermagem ; 242016 06 07.
Artículo en Inglés, Portugués, Español | MEDLINE | ID: mdl-27276015

RESUMEN

OBJECTIVE: to evaluate the quality of the sputum sample before and after the Nursing guidance to patients. METHODS: this is a quasi-experimental research design, single group type, before and after, non-randomized study. The study enrolled patients with suspected pulmonary tuberculosis, respiratory symptomatic patients for over three weeks, aged over 18 years, of both genders and without tuberculosis history in the last two years. The educational intervention consisted of individualized guidance on the collection of sputum sample, which was based on the guidelines of the Ministry of Health of Brazil and on the explanatory folder delivery. RESULTS: in this study participated 138 patients with suspected pulmonary tuberculosis. The results showed significant increase of the samples with purulent particles, volume greater than 5 mL and increased rate of patients diagnosed with tuberculosis, after the educational intervention. CONCLUSION: it was shown that after the educational intervention, it was observed sputum samples with better quality, with satisfactory aspect and volume for the effectiveness of the bacilloscopic examination.


Asunto(s)
Manejo de Especímenes , Esputo , Tuberculosis Pulmonar/diagnóstico , Educación en Enfermería , Femenino , Humanos , Masculino , Persona de Mediana Edad , Ensayos Clínicos Controlados no Aleatorios como Asunto , Guías de Práctica Clínica como Asunto
10.
Rev. latinoam. enferm. (Online) ; 24: e2703, 2016. tab
Artículo en Inglés | LILACS, BDENF - Enfermería | ID: biblio-960929

RESUMEN

Abstract Objective: to evaluate the quality of the sputum sample before and after the Nursing guidance to patients. Methods: this is a quasi-experimental research design, single group type, before and after, non-randomized study. The study enrolled patients with suspected pulmonary tuberculosis, respiratory symptomatic patients for over three weeks, aged over 18 years, of both genders and without tuberculosis history in the last two years. The educational intervention consisted of individualized guidance on the collection of sputum sample, which was based on the guidelines of the Ministry of Health of Brazil and on the explanatory folder delivery. Results: in this study participated 138 patients with suspected pulmonary tuberculosis. The results showed significant increase of the samples with purulent particles, volume greater than 5 mL and increased rate of patients diagnosed with tuberculosis, after the educational intervention. Conclusion: it was shown that after the educational intervention, it was observed sputum samples with better quality, with satisfactory aspect and volume for the effectiveness of the bacilloscopic examination.


Resumo Objetivo: avaliar a qualidade da amostra de escarro antes e após as orientações de Enfermagem ao paciente. Métodos: estudo com delineamento de pesquisa quase experimental, do tipo grupo único, antes e depois, não randomizado. Participaram do estudo pacientes com suspeita de tuberculose pulmonar, sintomáticos respiratórios por mais de três semanas, maiores de 18 anos, de ambos os sexos e sem antecedente de tuberculose nos últimos dois anos. A intervenção educativa consistiu em orientações individualizadas sobre a coleta da amostra de escarro, fundamentadas nas diretrizes do Ministério da Saúde do Brasil e na entrega de folder explicativo. Resultados: participaram 138 pacientes com suspeita de tuberculose pulmonar. Os resultados evidenciaram importante acréscimo das amostras com partículas purulentas, volume maior que 5mL e aumento na taxa de pacientes diagnosticados com tuberculose, após a intervenção educativa. Conclusão: comprovou-se que, após a intervenção educativa, obtiveram-se amostras de escarro com maior qualidade, com aspecto e volume satisfatórios para efetividade do exame baciloscópico.


Resumen Objetivo: evaluar la calidad de la muestra de esputo antes y después de las orientaciones de Enfermería al paciente. Métodos: de estudio con diseño de investigación casi experimental, del tipo grupo único, antes y después, no aleatorio. Participaron del estudio pacientes con sospecha de tuberculosis pulmonar, sintomáticos respiratorios por más de 3 semanas, mayores de 18 años, de los dos sexos y sin antecedente de tuberculosis en los últimos dos años. La intervención educativa consistió en orientaciones individualizadas sobre la recolección de la muestra de esputo, fundamentadas en las directrices del Ministerio de la Salud de Brasil y en la entrega de folder explicativo. Resultados: participaron 138 pacientes con sospecha de tuberculosis pulmonar. Los resultados evidenciaron un importante aumento de las muestras con partículas purulentas, volumen mayor que 5mL y aumento en la tasa de pacientes diagnosticados con tuberculosis, después de la intervención educativa. Conclusión: se comprobó que, después de la intervención educativa, se obtuvieron muestras de esputo con mejor calidad, con aspecto y volumen satisfactorios para efectividad del examen de baciloscopía.


Asunto(s)
Humanos , Masculino , Femenino , Persona de Mediana Edad , Manejo de Especímenes , Esputo , Tuberculosis Pulmonar/diagnóstico , Guías de Práctica Clínica como Asunto , Educación en Enfermería , Ensayos Clínicos Controlados no Aleatorios como Asunto
11.
Res. Biomed. Eng. (Online) ; 31(1): 33-43, Jan-Mar/2015. tab, graf
Artículo en Inglés | LILACS | ID: biblio-829412

RESUMEN

Introduction According to the Global TB control report of 2013, “Tuberculosis (TB) remains a major global health problem. In 2012, an estimated 8.6 million people developed TB and 1.3 million died from the disease. Two main sputum smear microscopy techniques are used for TB diagnosis: Fluorescence microscopy and conventional microscopy. Fluorescence microscopy is a more expensive diagnostic method because of the high costs of the microscopy unit and its maintenance. Therefore, conventional microscopy is more appropriate for use in developing countries. Methods This paper presents a new method for detecting tuberculosis bacillus in conventional sputum smear microscopy. The method consists of two main steps, bacillus segmentation and post-processing. In the first step, the scalar selection technique was used to select input variables for the segmentation classifiers from four color spaces. Thirty features were used, including the subtractions of the color components of different color spaces. In the post-processing step, three filters were used to separate bacilli from artifact: a size filter, a geometric filter and a Rule-based filter that uses the components of the RGB color space. Results In bacillus identification, an overall sensitivity of 96.80% and an error rate of 3.38% were obtained. An image database with 120-sputum-smear microscopy slices of 12 patients with objects marked as bacillus, agglomerated bacillus and artifact was generated and is now available online. Conclusions The best results were obtained with a support vector machine in bacillus segmentation associated with the application of the three post-processing filters.

12.
J. bras. patol. med. lab ; 49(5): 342-346, Oct. 2013. ilus
Artículo en Inglés | LILACS | ID: lil-697109

RESUMEN

Dermoid cysts or mature cystic teratomas are mesenchymal neoplasms most commonly found in the ovaries, but which may occur in any location along the pathways of ectodermal cell migration. They are rarely seen in the pancreas, where they show a slight preference for the pancreatic head. We report a case of dermoid cyst of the pancreas in a 69-year-old male patient, discussing the epidemiology, clinical presentation, diagnosis and treatment of this neoplasm. Since preoperative diagnosis is difficult, given its rarity in this site, it is usually diagnosed by histopathology of the specimen.


Cistos dermoides ou teratomas císticos maduros são neoplasias mesenquimais comumente encontradas nos ovários, mas que podem ocorrer em qualquer via de migração das células ectodérmicas. No pâncreas, a ocorrência é rara, sendo mais comum na cabeça pancreática. Relata-se caso de cisto dermoide do pâncreas em paciente masculino de 69 anos, discutindo-se epidemiologia, clínica, diagnóstico e tratamento dessa neoplasia, pouco suspeitada no pré-operatório devido à sua raridade nessa topografia; geralmente, é diagnosticada apenas pelo exame histopatológico da peça cirúrgica.

13.
Artículo en Inglés | MEDLINE | ID: mdl-23367361

RESUMEN

This paper presents a new method for segmentation of tuberculosis bacillus in conventional sputum smear microscopy. The method comprises three main steps. In the first step, a scalar selection are made for characteristics from the following color spaces: RGB, HSI, YCbCr and Lab. The features used for pixel classification in the segmentation step were the components and subtraction of components of these color spaces. In the second step, a feedforward neural network pixel classifier, using selected characteristics as inputs, is applied to segment pixels that belong to bacilli from the background. In third step geometric characteristics, especially the eccentricity, and a new proposed color characteristic, the color ratio, are used to noise filtering. The best sensitivity achieved in bacilli detection was 91.5%.


Asunto(s)
Microscopía/métodos , Mycobacterium tuberculosis/aislamiento & purificación , Humanos , Mycobacterium tuberculosis/clasificación , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Esputo/microbiología
14.
Artículo en Inglés | MEDLINE | ID: mdl-21095730

RESUMEN

This article presents a systematic analysis of focus functions in conventional sputum smear microscopy for tuberculosis. This is the first step in the development of automatic microscopy. Nine autofocus functions are analyzed in a set of 1200 images with varying degrees of content density. These functions were evaluated using quantitative procedures. The main accomplishment of this work was to show that an autofocus function based on variance measures produced the best results for tuberculosis images.


Asunto(s)
Interpretación de Imagen Asistida por Computador/instrumentación , Interpretación de Imagen Asistida por Computador/métodos , Microscopía/métodos , Esputo/metabolismo , Tuberculosis/diagnóstico , Tuberculosis/metabolismo , Algoritmos , Diseño de Equipo , Reacciones Falso Positivas , Humanos , Procesamiento de Imagen Asistido por Computador/métodos , Modelos Estadísticos , Reproducibilidad de los Resultados , Robótica/instrumentación , Robótica/métodos , Esputo/microbiología , Tuberculosis/microbiología
15.
Ann Surg Oncol ; 15(5): 1470-5, 2008 May.
Artículo en Inglés | MEDLINE | ID: mdl-18299937

RESUMEN

BACKGROUND: Renal graft recipients are one of the population groups known to be at high risk of developing anal cancer. This study investigated the presence of subclinical anal squamous intraepithelial lesions and the diagnostic ability of high-resolution anoscopy in detecting these lesions in renal graft recipients followed-up in Manaus. METHODS: In a cross-sectional study, 50 renal graft recipients were interviewed and submitted to high-resolution anoscopy with biopsies of acetowhite lesions or of the anal transition zone mucosa when acetowhitening was absent. Considering the histopathological reports of the examined anal specimens as the gold standard, the diagnostic validation and precision measures of high-resolution anoscopy were calculated as well as the prevalence of anal squamous intraepithelial lesions in the studied population. RESULTS: In 42 renal graft recipients with satisfactory histopathological readings, prevalence of anal squamous intraepithelial lesions or condyloma acuminatum (ASIL-ACU) was 23.81%. Sensitivity of high-resolution anoscopy was 100%; specificity, 65.63%; positive predictive value, 47.62%; negative predictive value, 100%; and kappa coefficient, 0.48. CONCLUSIONS: With a prevalence of 23.81% of subclinical ASIL-ACU lesions, the studied renal graft recipients had all these lesions detected by high-resolution anoscopy, notwithstanding most anal transition zone acetowhitened biopsied areas did not reveal histopathological aspects of anal cancer precursor lesions or condyloma acuminatum. Therefore, greater experience with the diagnostic tool was felt necessary to enhance its positive predictive value, specificity and diagnostic precision.


Asunto(s)
Canal Anal/patología , Neoplasias del Ano/diagnóstico , Carcinoma in Situ/diagnóstico , Carcinoma de Células Escamosas/diagnóstico , Trasplante de Riñón , Adulto , Neoplasias del Ano/epidemiología , Neoplasias del Ano/prevención & control , Carcinoma in Situ/epidemiología , Carcinoma in Situ/prevención & control , Carcinoma de Células Escamosas/epidemiología , Carcinoma de Células Escamosas/prevención & control , Estudios Transversales , Humanos , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias , Prevalencia , Pronóstico , Sensibilidad y Especificidad , Sigmoidoscopía
16.
J. bras. patol. med. lab ; 43(3): 195-201, maio-jun. 2007. tab
Artículo en Portugués | LILACS | ID: lil-460971

RESUMEN

INTRODUÇÃO: A tuberculose cutaneoganglionar (TbCG) corresponde a 25,4 por cento dos casos de tuberculose (Tb) extrapulmonar no estado do Amazonas. Os métodos tradicionais, bacteriológicos e histopatológicos envolvem algumas dificuldades diagnósticas, e a reação em cadeia da polimerase (PCR) surge como método alternativo, podendo propiciar resultados específicos e em menor tempo. Nesse sentido, verificou-se a acurácia do protocolo PCR4 de Marchetti et al. no diagnóstico da TbCG comparativamente aos métodos bacteriológicos e histopatológicos. MATERIAIS E MÉTODOS: Realizou-se o nested-PCR com oligonucleotídeos para a IS6110 do complexo do M. tuberculosis em 83 amostras parafinizadas, sendo 52 cutâneas e 31 ganglionares, de pacientes clinicamente suspeitos de TbCG. Todos os casos foram avaliados pelos métodos bacteriológicos e histopatológicos. Foi realizada análise da acurácia entre os resultados obtidos na PCR em relação ao cultivo e à histopatologia. RESULTADOS E DISCUSSÃO: A positividade da PCR em todos os casos estudados foi de 50,6 por cento (42/83), sendo de 59,6 por cento (31/52) em amostras cutâneas e de 35,5 por cento (11/31) nas ganglionares. Em ambos os grupos foram observados resultados falso-positivos e falso-negativos. Algumas hipóteses que podem justificar estes resultados estão relacionadas à presença da IS6110 em micobactérias ambientais da região amazônica e à não-padronização da amostra de DNA amplificado. CONCLUSÃO: O protocolo em avaliação apresentou positividade em percentual semelhante a diferentes protocolos existentes na literatura. Sugere-se o uso da PCR em tecidos parafinizados associada com o cultivo ou com a histopatologia para o diagnóstico definitivo de Tb ganglionar. Para as lesões cutâneas continua sendo necessária a busca de protocolo que amplie a acurácia do método.


BACKGROUND: Cutaneous lymph node tuberculosis (CLTb) represents 25.4 percent of all cases of extra-pulmonary Tb in the state of Amazonas. The current methods of diagnose including bacteriological and histopathological assays involve some technical difficulties, and the polymerase chain reaction - PCR arise as an alternative method allowing specific results faster than the others. In this context the accuracy of PCR4 Marchetti et al. protocol was compared with traditional methods. MATERIAL AND METHOD: Nested-PCR for IS6110 (123 pb) were applied on 83 CLTb suspicious formalin fixed and paraffin embedded samples of tissues (52 cutaneous and 31 lymph node), obtained from 1997 to 2002. All cases were evaluated by bacteriological and histopathological methods. Accuracy analyses were carried out between the PCR amplification results and those related on bacteriological and histopathological methods. RESULTS AND DISCUSSIONS: Positive results of PCR4 were about 50.6 percent (59.6 percent in cutaneous samples and of 35.5 percent in lymph nodes samples). In both groups were observed false-negative and false-positive results. Some hypotheses that explain those results are related to the presence of IS6110 in environmental mycobacterias in the Amazon region and the absence of standardized DNA concentration to amplification assays. CONCLUSIONS: The proposed protocol was as positive as others ones available in the literature. Definitive Tb diagnostic can be obtained on lymph node paraffin embedded PCR in association with bacteriological or histopathological method. A better accuracy of an amplification assay applied to cutaneous Tb suspicious lesions has to be still under research.


Asunto(s)
Humanos , Mycobacterium tuberculosis/aislamiento & purificación , Reacción en Cadena de la Polimerasa/métodos , Tuberculosis Cutánea/diagnóstico , Tuberculosis Ganglionar/diagnóstico , Adhesión en Parafina/métodos
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