The performance of an in-house nested-PCR technique for pleural tuberculosis diagnoses

Introduction This study evaluated the performance of an in-house nested-PCR system for the detection of the Mycobacterium tuberculosis complex in pleural fluid, blood and urine samples from pleural effusion tuberculosis patients by health services physicians in Pernambuco, Brazil. Methods A prospective double-blind study with 37 hospitalized patients of both sexes, aged over 15, was used to investigate the diagnosis of pleural effusion. The criteria used to define the cases included the demonstration of bacillus in biological samples by smear or culture or by a granulomatous finding in the histopathological examination, associated with an evident response to specific treatments to each clinical situation. Pleural fluid, blood and urine samples were collected and subjected to routine tests and the nested PCR technique to assess for M. tuberculosis amplification. Results In total, 37 pleural effusion patients took part in the study, of whom 19 (51.3%) had tubercular etiologies and 18 (48.7%) had etiologies from other causes. When the pleural fluid, blood and/or urine sample in-house nested-PCR sensitivities were evaluated simultaneously, the results were positive regardless of the biological specimen (the sensitivity was 84.2%); however, when the blood and/or urine samples were analyzed together, the sensitivity was 72.2%. When the pleural fluid samples were evaluated alone, the sensitivity was only 33.3%. Conclusions The performance of the diagnostic pleural tuberculosis nested-PCR was directly related to the diversity of the samples collected from the same patient. Additionally, this study may identify a need to prioritize non-invasive blood and urine collection for this diagnosis. .

Morphological analyses of caseous necrosis correlated to CD68+ and CD8+ cells in biopsies of tuberculous pleurisy / Análisis morfológico de la necrosis caseosa y su correlación con células CD68+ y CD8+ en biopsias de pleuritis tuberculosa

Tuberculosis is the most prevalent infectious disease in the world. Granuloma formation and caseous necrosis are hallmarks of M. tuberculosis infection and they represent the protective and inflammatory reactions in the infected tissues. The molecular mechanisms that mediate granuloma necrosis are still not well understood. Objectives: To immunolocalize and correlate the amounts of CD68+ macrophages and CD8+ lymphocytes to caseous necrosis extension in granulomas of tuberculous pleurisy. Methods: The study is a retrospective analysis of 30 pleural biopsies with histopathological diagnosis of chronic granulomatous pleurisy with caseous necrosis. These biopsies were classified according to necrosis intensity as minimal (N1), moderate (N2) and intense (N3). The number of granulomas was also observed and categorized as G1 (1 to 4 granulomas per section), G2 (5 to 8 granulomas per section), and G3 (more than 8 granulomas per section). Results: The means of CD68+ cells counts per mm² in N1, N2 and N3 categories of necrosis were 1,287 +/- 254, 1086 +/- 181 and 930 +/- 115 respectively. The means for CD8+ cells were 483.7 +/- 396, 366.3 +/- 43 and 558 +/- 53 cells per mm² in N1, N2 and N3 respectively. Conclusions: There were no significant statistical correlations between necrosis extension and cell counts. In analyzed biopsies, the number of CD68+ cells was significantly higher than the number of CD8+ cells.

La tuberculosis es una de las enfermedades más prevalentes en el mundo. La formación del granuloma junto con la necrosis caseosa son características propias de la infección por M. tuberculosis y representan reacciones inflamatorias y protectoras en los tejidos infectados. No se conocen bien los mecanismos moleculares que median la necrosis en el granuloma. Los objetivos fueron inmunolocalizar y correlacionar la cantidad de macrófagos CD68+ y linfocitos CD8+ con la extensión de la necrosis caseosa, en los granulomas de tuberculosis pleural. Análisis retrospectivo que incluyeron 30 biópsias con diagnóstico histopatológico de tuberculosis pleural granulomatosa crónica con necrosis caseosa. Estas biópsias fueron clasificadas según la intensidad de necrosis como mínima (N1), moderada (N2) e intensa (N3). También se determinó el número de granulomas, que fueron clasificados como G1 (1 a4 granulomas por sección), G2 (5 a 8 granulomas por sección), y G3 (más de 8 granulomas por sección). La cuantificación de células CD68+ por mm² en las categorías N1, N2 y N3 de necrosis fue de 1,287 +/- 254; 1086 +/-181 y 930 +/- 115, respectivamente. La cuantificación de las células CD68+ fue de 483,7 +/- 396; 366,3 +/- 43 y 558 +/- 53 células por mm² para N1, N2 y N3, respectivamente. No hubo correlación estadísticamente significativa entre la extensión de la necrosis y la cuantificación celular. El número de células CD68+ fue significativamente mayor que el número de células CD8+ en las biópsias analizadas.

Leptin response in patients with tuberculous pleuritis.

BACKGROUND & OBJECTIVES: Tuberculous pleuritis is used as a model to understand the protective immune response in tuberculosis. It is predominated by Th1 response at the site of infection, where a possible role for the leptin, a known enhancer of Th1 response, could be speculated. Hence, we investigated leptin levels in pleural effusions in patients with both tuberculous (TP) and non-tuberculous (NTP) pleural effusion. METHODS: Leptin and cytokine levels were assessed in serum and pleural fluid of TP and NTP patients (N = 20 each) by ELISA. Multivariate regression analysis were performed to find the possible determinants of leptin taking leptin as the dependent and body mass index (BMI), gender, source of leptin [i.e., serum or pleural fluid (PF)], age and disease status as independent variables. RESULTS: PF leptin levels were significantly higher than serum leptin levels in both the groups however the PF leptin levels were significantly lower in TP subjects compared to NTP. The results showed that the leptin was found to be dependent on BMI but not on the other parameters. However, regression analysis based on the source of leptin showed males to be a better predictor of leptin. No correlation was observed between leptin and measured immune parameters. INTERPRETATION & CONCLUSION: Our findings demonstrated that the decreased leptin levels were associated with reduction in BMI but not with the disease status in tuberculous pleuritis.

Malignant and tuberculous pleural effusions: immunophenotypic cellular characterization

INTRODUCTION AND OBJECTIVES: Tuberculosis and cancer are the main causes of pleural effusion. Pleural involvement is associated with migration of immune cells to the pleural cavity. We sought to characterize the immunophenotype of leukocytes in the pleural effusion and peripheral blood of patients with tuberculosis or malignancy. METHODS: Thirty patients with tuberculosis (14) or malignancy (16) were studied. A control group included 20 healthy blood donors. RESULTS: Malignant phycoerythrin pleural effusions showed higher percentages of CD3, CD4, CD3CD45RO, and CD20CD25 lymphocytes and lower percentages of CD3CD25 and CD20HLA-DR when compared to PB lymphocytes. Compared to PB, tuberculous effusions had a higher percentage of lymphocytes that co-expressed CD3, CD4, CD3CD45RO, CD3TCRáâ, CD3CD28, and CD20 and a lower percentage of CD14, CD8 and CD3TCRãä-positive lymphocytes. Malignant effusions presented higher expression of CD14 whereas tuberculous effusions had higher expression of CD3 and CD3CD95L. Peripheral blood cells from tuberculosis patients showed higher expression of CD14, CD20CD25 and CD3CD95L. Compared with the control cells, tuberculosis and cancer peripheral blood cells presented a lower percentage of CD3CD4 and CD3CD28-positive cells as well as a higher percentage of CD3CD8, CD3CD25 and CD3CD80-positive cells. CONCLUSIONS: Tuberculous and malignant peripheral blood is enriched with lymphocytes with a helper/inducer T cell phenotype, which are mainly of memory cells. CD14-positive cells were more frequently found in malignant effusions, while CD3-positive cells expressing Fas ligand were more frequently found in tuberculous effusions.