Márcia Seiscento

Imagem em tuberculose pulmonar

Tuberculosis is a disease of high incidence and prevalence in Brazil. Imaging methods can reveal signs suggestive of tuberculosis activity or sequelae. Chest radiographs can reveal active lung tuberculosis through consolidations, cavitations, interstitial patterns (nodular and reticulo-nodular), mediastinal or hilar lymphadenopathy and pleural effusions. Images compatible with the active disease, such as centrilobular nodules segmentarily distributed, thick-walled cavities, thickened bronchial or bronchiolar walls, bronchiectasis and lymphadenopathy can be observed by computerized tomography. Thin-walled cavities, traction bronchiectasis, parenchymal bands, emphysema and mosaic pattern are signs suggestive of inactive disease. Gallium-67 citrate scyntigraphy is a complementary method useful in the detection of infectious diseases, including tuberculosis, especially in immunocompromised patients. Inhalation / perfusion analyses are used in the pre-operative assessment of patients carrying tuberculosis sequelaes and multiresistant tuberculosis. Positron emission tomography with fluorine-18 labeled deoxyglucose allows the detection of the inflammatory process that takes place during the active stage of tuberculosis and may persist, not so intense, after specific treatment is over. Imaging methods are valuable tools to be used in the diagnosis and follow up of pulmonary tuberculosis.

Tuberculose e silicose: epidemiologia, diagnóstico e quimioprofilaxia

Silicosis, the most prevalent of the pneumoconioses, is caused by inhalation of crystalline silica particles. Silica-exposed workers, with or without silicosis, are at increased risk for tuberculosis and nontuberculous mycobacteria-related diseases. The risk of a patient with silicosis developing tuberculosis is higher (2.8 to 39 times higher, depending on the severity of the silicosis) than that found for healthy controls. Various regimens for tuberculosis chemoprophylaxis in patients with silicosis have been studied, all of which present similar efficacy and overall risk reduction to about one half of that obtained with placebo. Long-term regimens have potential side effects (particularly hepatotoxicity). In addition, the use of such regimens can jeopardize adherence to treatment. The current guidelines recommend that tuberculin skin tests be performed, and, if positive, that chemoprophylaxis be instituted. There are several possible regimens, varying in terms of the drugs prescribed, as well as in terms of treatment duration. We recommend the use of isoniazid at 300 mg/day (or 10 mg/kg/day) for six months for patients with silicosis, as well as for healthy patients with periods of exposure to silica longer than 10 years and strongly positive tuberculin skin test results (induration > 10 mm). Nevertheless, further studies are necessary so that indications, drugs, doses and duration of chemoprophylaxis regimens can be more properly defined.

Predictive models for diagnosis of pleural effusions secondary to tuberculosis or cancer

Background and objective:  Tuberculosis (TB) and cancer are two of the main causes of pleural effusions which frequently share similar clinical features and pleural fluid profiles. This study aimed to identify diagnostic models based on clinical and laboratory variables to differentiate tuberculous from malignant pleural effusions.

Clinical and laboratory parameters in the differential diagnosis of pleural effusion secondary to tuberculosis or cancer

PURPOSE To evaluate the clinical and laboratory characteristics of pleural effusions secondary to tuberculosis (TB) or cancer (CA). METHODS A total of 326 patients with pleural effusion due to TB (n=182) or CA (n=144) were studied. The following parameters were analyzed: patient gender, age and pleural effusion characteristics (size, location, macroscopic fluid aspect, protein concentration, lactate dehydrogenase (DHL) and adenosine deaminase activity (ADA) and nucleated cell counts). RESULTS Young male patients predominated in the tuberculosis group. The effusions were generally moderate in size and unilateral in both groups. Yellow-citrine fluid with higher protein (p < 0.001) levels predominated in effusions from the tuberculosis group (5.3 + 0.8 g/dL) when compared to the CA group (4.2 +/- 1.0 g/dL), whereas DHL levels were more elevated in CA (1,177 +/- 675 x 1,030 +/- 788 IU; p = 0.003) than in TB. As expected, ADA activity was higher in the TB group (107.6 +/- 44.2 x 30.6 +/- 57.5 U/L; p < 0.001). Both types of effusions presented with high nucleated cell counts, which were more pronounced in the malignant group (p < 0.001). TB effusion was characterized by a larger percentage of leukocytes and lymphocytes (p < 0.001) and a smaller number of mesothelial cells (p = 0.005). Lymphocytes and macrophages were the predominant nucleated cell in neoplastic effusions. CONCLUSION Our results demonstrate that in lymphocytic pleural exudate obtained from patients with clinical and radiological evidence of tuberculosis, protein and ADA were the parameters that better characterize these effusions. In the same way, when the clinical suspicion is malignancy, serous-hemorrhagic lymphocytic fluid should be submitted to oncotic cytology once this easy and inexpensive exam reaches a high diagnostic performance (approximately equal 80%). In this context, we suggest thoracocentesis with fluid biochemical and cytological examination as the first diagnostic approach for these patients.

Aspectos epidemiológicos da tuberculose pleural no estado de São Paulo (1998-2005)

OBJECTIVE To analyze the epidemiological characteristics of and trends regarding the incidence of pleural TB. METHODS This was a retrospective descriptive study of TB cases reported between 1998 and 2005 and compiled from the Epidemiological Surveillance Tuberculosis System (Epi-TB database). RESULTS A total of 144,347 new cases of TB were reported during the period studied. Pulmonary TB was the predominant form (118,575 cases; 82.2%). Among the extrapulmonary forms (25,773 cases; 17.8%), pleural TB was the form most often reported (12,545 cases; 48.7%). For all forms, the incidence (per 100,000 population) decreased (from 49.7 in 1998 to 44.6 in 2005; R(2) = 0.898; p < 0.001), whereas the incidence of pleural TB remained stable (4.1 in 1998 and 3.8 in 2005; R(2) = 0.433; p = 0.076). The highest incidence of pleural TB was found among males (2:1) aged from 30 to 59 years. Of the 12,545 patients with pleural TB, 4,018 (32.0%) presented comorbidities: alcoholism (9.5%); HIV (8.0%); diabetes (3.3%); and mental illness (1.2%). The diagnosis was based on bacteriological (14.2%) and histological (30.2%) methods, as well as on unspecified methods (55.6%). CONCLUSIONS Pleural TB was the predominant extrapulmonary form of TB in the state of São Paulo, with a stable incidence between 1998 and 2005, although there was a trend toward a decrease in the incidence of the pulmonary forms. The diagnosis of pleural TB was confirmed through histology and bacteriology in 44.4% of the cases.

Transforming growth factor β-1 as a predictor of fibrosis in tuberculous pleurisy

Background and objective:  To clarify the influence of transforming growth factor β‐1 (TGF‐β1) in the development of pleural thickening in tuberculosis (TB), the levels of TGF‐β1 in pleural fluid and in serum of patients with pleural TB and transudative effusions were determined.

Pulmonary tuberculosis: tomographic evaluation in the active and post-treatment phases

CONTEXT Adequate knowledge of images consistent with tuberculosis activity is an important resource for tuberculosis diagnosis and treatment. OBJECTIVE To evaluate the structural alterations caused by tuberculosis in the pulmonary parenchyma, both during the active phase of the disease and after the end of the treatment, through computerized tomography of the thorax. TYPE OF STUDY Prospective study. SETTING Pulmonary Division, Hospital das Clínicas, Faculdade de Medicina da Universidade de São Paulo. PARTICIPANTS 20 patients, carriers of pulmonary tuberculosis, confirmed by Mycobacterium tuberculosis culture. PROCEDURES Conventional tomography scans of the patients were obtained at two times: upon diagnosis and after the end of the treatment. The following were considered suggestive signs of tuberculosis activity: centrilobular nodules with segmented distribution, confluent micronodules, consolidations, thick-walled cavities, nodules, masses, thickening of the bronchial walls, tree-in-bud appearance and cylindrical bronchiectasis. MAIN MEASUREMENTS The presence of suggestive signs of tuberculosis activity was compared between the start and the end of treatment by means of the signs test (z). RESULTS All patients (20/20) presented suggestive signs of tuberculosis activity at the start of treatment. After the end of treatment, 13 patients (13/20) still presented some suggestive signs consistent with activity. A reduction in the extent of lung attack was seen post-treatment, in relation to its start (z = 10.10). This change was statistically significant (p < 0.001). CONCLUSION Signs suggestive of tuberculosis activity are present in the active disease and are seen via computed tomography. The extent of parenchymal attack significantly decreases following treatment. Such signs may be useful in the diagnosis of pulmonary tuberculosis.

Pulmonary involvement in pleural tuberculosis: How often does it mean disease activity?

OBJECTIVE To evaluate in chest X-rays and high-resolution computed tomographies of patients with pleural tuberculosis, the incidence of parenchymal and mediastinal lung lesions suggestive of active disease. METHODS Prospective study (2008-2009) evaluating the radiographic and tomographic abnormalities of 88 HIV-negative patients with pleural tuberculosis (unilateral effusion). The images were reviewed by 3 independent specialists, and the observed changes were classified according to previously established criteria: presence or absence of signs suggestive of disease activity, and nonspecific findings. RESULTS Abnormal changes were observed in chest X-rays of 22 (25%) patients and in the computed tomography of 55 (63%). Images compatible with active pulmonary tuberculosis were detected by radiography in 9 (10%) patients and by tomography in 38 (43%). Only 4 (4.5%) patients had tomography images suggestive of residual disease. CONCLUSION The present study demonstrates that pulmonary involvement is quite common in pleural tuberculosis. This finding is mainly observed in high-resolution computed tomography and has important epidemiological implications, since patients with pleural tuberculosis are significant sources of infection and disease dissemination.

Tuberculous pleural effusions

Tuberculous pleural effusion is a common manifestation of the primary form of the disease or consequence of the reactivation of a latent infection due to the M. tuberculosis. Advances in the laboratory methods have contributed to better diagnose and understand the pathophysiology of the effusion secondary to tuberculosis. However, although a predominant lymphocytic pleural effusion is suspicious of tuberculosis, a diagnostic routine shall be instituted to orient treatment and prevent undesirable sequels.

Pleural tuberculosis: is radiological evidence of pulmonary-associated disease related to the exacerbation of the inflammatory response?

OBJECTIVE: Pleural tuberculosis is the most frequently occurring form of extra pulmonary disease in adults. In up to 40% of cases, the lung parenchyma is concomitantly involved, which can have an epidemiological impact. This study aims to evaluate the pleural and systemic inflammatory response of patients with pleural or pleuropulmonary tuberculosis. METHODS: A prospective study of 39 patients with confirmed pleural tuberculosis. After thoracentesis, a high resolution chest tomography was performed to evaluate the pulmonary involvement. Of the 39 patients, 20 exhibited only pleural effusion, and high resolution chest tomography revealed active associated-pulmonary disease in 19 patients. The total protein, lactic dehydrogenase, adenosine deaminase, vascular endothelial growth factor, interleukin-8, tumor necrosis factor-α, and transforming growth factor-β1 levels were quantified in the patient serum and pleural fluid. RESULTS: All of the effusions were exudates with high levels of adenosine deaminase. The levels of vascular endothelial growth factor and transforming growth factor-β1 were increased in the blood and pleural fluid of all of the patients with pleural tuberculosis, with no differences between the two forms of tuberculosis. The tumor necrosis factor-α levels were significantly higher in the pleural fluid of the patients with the pleuropulmonary form of tuberculosis. The interleukin-8 levels were high in the pleural fluid of all of the patients, without any differences between the forms of tuberculosis. CONCLUSION: Tumor necrosis factor-α was the single cytokine that significantly increased in the pleural fluid of the patients with pulmonary involvement. However, an overlap in the results does not permit us to suggest that cytokine is a biological marker of concomitant parenchymal involvement. Although high resolution chest tomography can be useful in identifying these patients, the investigation of fast acid bacilli and cultures for M. tuberculosis in the sputum is recommended for all patients who are diagnosed with pleural tuberculosis.