Tuberculosis pleural en paciente pediátrico: reporte de un caso y revisión de la literatura / Pleural tuberculosis in a pediatric patient: case report and review

Tuberculosis (TB) is a common cause of pleural effusion in young people from endemic areas. Among the forms of extrapulmonary TB in people with immunodeficiencies, the most frequent localization is the pleura. The use of immunological and molecular biology tests for the diagnosis of TB in pleural fluid and other locations with high sensitivity and specificity is highlighted. We present a clinical case with the objective of giving an overview of the treatment of the patient with suspected pleural tuberculosis

La Tuberculosis (TB) es una causa común de derrame pleural en jóvenes en zonas endémicas. Dentro de las formas de TB extrapulmonar en personas que cursan con inmunodeficiencias, la localización más frecuente es la TB pleural. Se destaca el uso de las pruebas inmunológicas y de biología molecular para el diagnóstico de TB en líquido pleural y de otras localizaciones con una elevada sensibilidad y especificidad. Se presenta un caso clínico con el objetivo de describir una visión general del abordaje del paciente con sospecha de tuberculosis pleural

Pleural effusion adenosine deaminase: a candidate biomarker to discriminate between Gram-negative and Gram-positive bacterial infections of the pleural space

OBJECTIVES: Delay in the treatment of pleural infection may contribute to its high mortality. In this retrospective study, we aimed to evaluate the diagnostic accuracy of pleural adenosine deaminase in discrimination between Gram-negative and Gram-positive bacterial infections of the pleural space prior to selecting antibiotics. METHODS: A total of 76 patients were enrolled and grouped into subgroups according to Gram staining: 1) patients with Gram-negative bacterial infections, aged 53.2±18.6 years old, of whom 44.7% had empyemas and 2) patients with Gram-positive bacterial infections, aged 53.5±21.5 years old, of whom 63.1% had empyemas. The pleural effusion was sampled by thoracocentesis and then sent for adenosine deaminase testing, biochemical testing and microbiological culture. The Mann-Whitney U test was used to examine the differences in adenosine deaminase levels between the groups. Correlations between adenosine deaminase and specified variables were also quantified using Spearman’s correlation coefficient. Moreover, receiver operator characteristic analysis was performed to evaluate the diagnostic accuracy of pleural effusion adenosine deaminase. RESULTS: Mean pleural adenosine deaminase levels differed significantly between Gram-negative and Gram-positive bacterial infections of the pleural space (191.8±32.1 U/L vs 81.0±16.9 U/L, p<0.01). The area under the receiver operator characteristic curve was 0.689 (95% confidence interval: 0.570, 0.792, p<0.01) at the cutoff value of 86 U/L. Additionally, pleural adenosine deaminase had a sensitivity of 63.2% (46.0-78.2%); a specificity of 73.7% (56.9-86.6%); positive and negative likelihood ratios of 2.18 and 0.50, respectively; and positive and negative predictive values of 70.6% and 66.7%, respectively. CONCLUSIONS: Pleural effusion adenosine deaminase is a helpful alternative biomarker for early and quick discrimination of Gram-negative from Gram-positive bacterial infections of the pleural space, which is useful for the selection of antibiotics.

Biomarcadores diagnósticos de tuberculose em pleurologia / Diagnostic biomarkers of tuberculosis in pleurologia

Atualmente o diagnóstico de tuberculose pleural pode ser realizado com a dosagem de biomarcadores diagnósticos no líquido pleural, especificamente com a dosagem da enzima adenosina desaminase. Os quadros clínico, laboratorial, imagem e citopatologia sugestivos sempre devem ser valorizados no conjunto do diagnóstico. Tal abordagem elege somente o procedimento de toracocentese como necessário para início do diagnóstico. Na maioria das apresentações clínicas, procedimentos cirúrgicos mais invasivos (biopsias pleurais), com complicações potencialmente fatais, não precisam ser realizados para exame histopatológico

Currently the diagnosis of pleural tuberculosis can be performed with the dosage of diagnostic biomarkers in pleural fluid, specifically the enzyme adenosine deaminase. The clinical, imaging and cytology suggestive should always be valued in the set of diagnosis together laboratory measurements. This approach selects only a thoracentesis procedure for early diagnosis. In most clinical presentations, more invasive surgical procedures (pleural biopsies) with life-threatening complications for histopathological examination

Validação laboratorial de um método automatizado de dosagem da atividade de adenosina desaminase em líquido pleural e em líquido cefalorraquidiano / Laboratorial validation of an automated assay for the determination of adenosine deaminase activity in pleural fluid and cerebrospinal fluid

OBJETIVO: A incidência global de tuberculose reforça a necessidade de melhores ensaios para o diagnóstico desta doença, principalmente da tuberculose extrapulmonar. O objetivo do trabalho foi validar o desempenho de um método automatizado para a determinação da atividade de adenosina desaminase (ADA) no líquido pleural (LP) e no líquido cefalorraquidiano (LCR), comparando-o com um método convencional (Giusti modificado). MÉTODOS: Selecionaram-se 134 amostras da rotina laboratorial: 94 de LP e 40 de LCR. Foram realizadas as determinações da atividade de ADA através dos dois métodos. Calculou-se a precisão inter- e intra-ensaios, análise de regressão linear, testes de concordância simples e médias das diferenças. RESULTADOS: Os coeficientes de correlação para as amostras de LP e LCR foram, respectivamente, 0,96 e 0,95. A precisão interensaio foi determinada pela média de 21 amostras replicadas em ensaios diferentes para 3 níveis de atividade: baixa, média e alta. Os coeficientes de variação em porcentagem ( por centoCV) foram, respectivamente, 5,9, 8,1 e 5,8 para amostras de LP; e 21,9, 18,6 e 13,8 para amostras de LCR, respectivamente. A precisão intra-ensaio em por centoCV foi, respectivamente, 1,3 e 11,7 por cento para amostras de LP e LCR. A concordância entre os dois métodos em amostras de LP e LCR foi, respectivamente, 96,8 por cento e 100 por cento, considerando-se como valores de referência para o diagnóstico de TB 40 U/L (convencional) e 30 U/L (automatizado) em amostras de LP, e 9 U/L em amostras de LCR para os dois métodos. CONCLUSÕES: Os resultados validaram o método automatizado de determinação da atividade de ADA para o uso em amostras de LP e LCR como alternativa ao método convencional.

OBJECTIVE: The incidence of tuberculosis worldwide has emphasized the need for better assays designed to diagnose the disease, principally the extrapulmonary form. The objective of the present study was to validate the performance of an automated method for the determination of adenosine deaminase (ADA) activity in pleural fluid (PF) and cerebrospinal fluid (CSF), comparing it with a conventional method (the modified Giusti method). METHODS: In total, 134 samples were selected from among those tested in our laboratory: 94 PF samples and 40 CSF samples. The ADA activity was determined using the two methods. Inter- and intra-assay precision was determined, linear regression analysis was performed, simple concordance tests were conducted, and the means of the differences were calculated. RESULTS: The correlation coefficients for PF and CSF samples were, respectively, 0.96 and 0.95. Inter-assay precision was determined using 21 replicates at 3 different activity levels: low, medium and high. The percentage coefficient of variation ( percentCV) was, respectively, 5.9, 8.1 and 5.8 for PF samples, compared with 21.9, 18.6 and 13.8 for CSF samples. Intra-assay precision in percentCV was 1.3 and 11.7, respectively, for PF and CSF samples. The concordance between the methods in PF and CRF samples was, respectively, 96.8 percent and 100 percent, considering the reference values for the diagnosis of TB to be 40 U/L (conventional) and 30 U/L (automated) in PF samples, versus 9 U/L (for both methods) in CSF samples. CONCLUSIONS: The results validate the use of the automated method of determining ADA activity in PF and CSF samples as an alternative to the conventional method.

Diagnostic utility of adenosine deaminase (ADA) activity in pleural fluid and serum of tuberculous and non-tuberculous respiratory disease patients.

Adenosine deaminase activity (ADA) was assayed in pleural fluid and serum of 42 subjects with pleural effusion. Twenty-nine of them had TB pleural effusion and the remaining 13 had pleural effusion due to non-TB respiratory diseases. Serum adenosine deaminase activity were also measured in 32 pulmonary tuberculosis patients without pleural effusion and equal numbers of healthy controls without systemic diseases for comparative analysis. The patients attending the medicine out-patient department (MOPD) of the B. P. Koirala Institute of Health Sciences, Dharan, Nepal were taken as study subjects. Serum and pleural fluid ADA activities were assayed spectrophotometrically by the method of Guisti and Gallanti. The mean serum ADA activity was significantly increased in patients with tubercular pleural effusion (34.53 +/- 10.27 IU/l) compared to pulmonary tuberculosis patients without pleural effusion (26.54 +/- 4.76 IU/l), (p = 0.004), those with non-TB respiratory disease (16.71 +/- 5.16 IU/l), (p = 0.0001) and healthy controls (15.53 +/- 4.4 IU/l) (p = 0.0001). The mean ADA in the pleural fluid of tubercular pleural effusion patients (90.29 +/- 54.80 IU/l) was significantly higher compared to those with non-TB respiratory disease (24.43 +/- 9.28 IU/l) (p = 0.0001). Using the lowest cutoff value for enzyme activity in the serum of patients with TB pleural effusion (25 IU/l), a test sensitivity of 72.41% and specificity of 81.53% were obtained. Using the lowest cutoff value for enzyme activity in pleural fluid of patients with TB pleural effusion (45 IU/l) the sensitivity and specificity for diagnosis were 76.10% and 100%, respectively. Therefore, the measurement of ADA in tubercular pleural effusion has a utility in the diagnosis of tuberculosis when other clinical and laboratory tests are negative.

Predictive model for the diagnosis of tuberculous pleural effusion

This study developed a predictive model to identify pleural tuberculosis. A consecutive cases study of patients investigating the cause of pleural effusion, in an area of high prevalence of tuberculosis (Rio de Janeiro, Brazil). Clinical and laboratory variables were compared among patients with tuberculosis (TB) and without tuberculosis (NTB), individually and using logistic regression. The performance was described as diagnostic accuracy, compared to a gold standard in a masked way. We have studied 104 TB patients, 41 with malignant, 29 transudates, 28 parapneumonic, 13 with miscellaneous diseases. After identification of individual discrimination power aided by clinical, radiological and laboratory variables, the following ones were included in a multivariate analysis: ADA, total leukocytes, percentile of lymphocytes, protein, lactate dehydrogenase, duration of disease, age and gender. A logistic regression model to predict pleural tuberculosis including the five first variables showed the best performance. A receiver operating characteristic curve identified the best cutoff at 0.7, resulting in a sensitivity and specificity of more then 95 percent. The predictive model improved the specificity of ADA alone, keeping its sensitivity. This model seems helpful when a microbiological or histological diagnosis of pleural tuberculosis could not be established. External validation of these results is necessary before recommendation for routine application.

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 80 percent). In this context, we suggest thoracocentesis with fluid biochemical...

OBJETIVO: Avaliar as características clínicas e laboratoriais de derrames pleurais secundários à tuberculose ou câncer. MÉTODOS: Um total de 326 pacientes com derrame pleural por tuberculose (n=182) ou câncer (n=144) foi avaliado. Os seguintes parâmetros foram analisados: sexo e idade dos pacientes e características do líquido pleural (tamanho, localização, aspecto macroscópico, concentração de proteínas, atividade da desidrogenase lática (DHL) e da adenosina deaminase (ADA) e contagem de células nucleadas). RESULTADOS: A tuberculose pleural predominou nos pacientes mais jovens e do sexo masculino. Em ambos os grupos, os derrames pleurais foram de tamanho moderado e unilaterais. Derrames com aspecto amarelo-citrino com níveis mais elevados de proteínas predominaram na tuberculose (5,3 ± 0,8 g/dL), quando comparados aos neoplásicos (4,2 ± 1,0 g/dL), enquanto que níveis mais elevados de DHL foram observados nos derrames neoplásicos (1.177 ± 675 x 1.030 ± 788 UI; p = 0,003). Conforme esperado, a atividade da ADA foi maior na tuberculose que no câncer (107,6 ± 44,2 x 30,6 ± 57,5 U/L; p < 0,001). Ambos os derrames apresentaram alta celularidade, embora mais pronunciada no grupo neoplásico (p < 0,001). Os derrames de etiologia tuberculosa se caracterizaram por apresentar uma maior percentagem de leucócitos e de linfócitos (p < 0,001) e um pequeno número de células mesoteliais (p = 0,005). Linfócitos e macrófagos foram as células nucleadas que predominaram nos derrames pleurais malignos. CONCLUSÃO: Nossos resultados demonstram que em exsudatos pleurais linfocíticos de pacientes com evidências clínicas e radiológicas de tuberculose, os níveis de proteína e de ADA foram os parâmetros que melhor caracterizaram esses derrames. Da mesma maneira, quando a suspeita clínica é câncer, um líquido serohemorrágico e linfocítico deve ser submetido à citologia oncótica, uma vez que este exame laboratorial de fácil...

Diagnostic value of Adenosine deaminase isoenzyme [ADA2] and total ADA in tuberculous pleural effusion

Determination of adenosine deaminase [ADA] activity is one of the most promising markers in diagnosing of tuberculous pleural effusion. ADA has two main isoenzymes: ADA1 and ADA2.The ADA2 is the predominant isoform in tuberculous pleural effusion, suggesting its important role as a diagnostic marker. This study was conducted to determine the diagnostic value of ADA and ADA2 measurement in tuberculous pleural effusion. Total ADA and ADA2 isoenzyme activities were measured in 93 case of pleural effusion, including tuberculosis [26males/5females], malignancy [22males/8females], empyema and para-pneumonic [11males/4females], transudate [6males/4females], rheumatoid arthritis and idiopathic [4males/3females]. ADA levels were determined by Giusti and Galanti methods. ADA2 was measured with a potent inhibitor of ADA1 isoenzyme. Total ADA and ADA2 activities in tuberculous exudates were 96.6 +/- 29.1 and 74.4 +/- 29 U/L, respectively. With diagnostic thresholds of 46 and 42 U/L, the sensitivities of ADA and ADA2 for tuberculous exudates were 100% and 97%; their specificities 82 and 88%; and their efficiencies 88% and 93.5%, respectively. All tuberculous exudates, 2 neoplastic, 8 para- infective [including 4 empyemas] and one rheumatoid arthritis had total ADA levels > 46 U/L; of these, only one lymphoma and one rheumatoid arthritis had ADA2/ADA activity ratio > 50%. Considering simultaneous criteria of total ADA more than 46U/L, ADA2 > 42 U/L and ADA2/ADA more than 50%, we had only two false positive results, rising the specificity up to 96%. 1. ADA2 is a more efficient diagnostic marker for Tuberculous pleural effusion compared with total ADA. 2. Overall, diagnostic value of ADA would be enhanced by the determination of its isoenzymes, especially for distinguishing between the tuberculous and para-infective effusions

Status of lipid peroxidation and antioxidant enzymes in malignant (bronchogenic carcinoma) and non-malignant pleural effusions.

Eighty patients from Chennai Medical College (patients with bronchogenic carcinoma) and from Tambaram Tuberculosis Hospital (patients with non-malignant pulmonary diseases mainly tuberculosis) in whom the etiologic diagnosis of their pleural effusions are confirmed were included in the study. Lipid peroxidation (LPO) and activities of antioxidant enzymes were estimated in pleural exudates of the two groups. Lipid peroxidation was found to be increased and the status of antioxidants were found to be decreased in lung malignant pleural exudates when compared to those of non-malignant effusions. The possible reasons for the observed results discussed.

Importåncia da determinaçåo da enzima adenosina deaminase (ADA) no diagnóstico da tuberculose / The importance of adenosine deaminase (ADA) determination in tuberculosis diagnosis

Os autores enfatizam a importância da utilizaçåo da atividade de adenosina deaminase como um critério útil no diagnóstico do derrame pleural, peritonite e meningite de etiologia tuberculosa. As características destas enzima e os principais estudos evidenciando sua utilidade no diagnóstico das diferentes formas de tuberculose såo também abordados. Os autores ainda apresentam as metodologias disponíveis para sua determinaçåo, ressaltando que a simplicidade de execuçåo técnica é vantajosa na rotinizaçåo laboratorial

Poor diagnostic value of adenosine deaminase in pleural, peritoneal & cerebrospinal fluids in tuberculosis.

Adenosine deaminase (ADA) was estimated in 84 pleural, 140 peritoneal and 136 cerebrospinal fluids to study its diagnostic usefulness as a routine test for tuberculosis. The sensitivity, specificity, positive and negative predictive values for diagnosing tuberculosis in pleural fluids (ADA > 30 U/l) was 67, 92, 78 and 87 per cent respectively, in peritoneal fluids (ADA > 15 U/1) it was 89, 81, 25 and 99 per cent respectively and in cerebrospinal fluids (ADA > 10 U/l) it was 50, 90 21 and 97 per cent respectively. The differences in mean ADA levels between tuberculous (28.0 and 19.5 U/1) and non-tuberculous (9.7 and 4.8 U/1) peritoneal and cerebrospinal fluids although statistically significant (P < 0.001), were of no practical clinical value. A wide scatter in ADA values was seen in both tuberculous and non-tuberculous fluids. ADA estimation in plasma, lymphocytes and cell fractions of fluids was also not diagnostically useful nor did it throw light on the source of elevated ADA in fluids.

Adenosin-deaminasa en líquido pleural / Adenosin-deaminasa in pleural effusion

Se estudiaron en forma prospectiva, 120 pacientes con derrame pleural (excluídos empiemas, derrames paraneumónicos y trasudados), con el fin de establecer la utilidad de la determinación de adenosin-deaminasa (ADA) en liquido pleural y suero, frente a otros métodos en el diagnóstico particularmente de la tuberculosis pleural. 54 (45 por ciento) de ellos egresaron con diagnóstico de tuberculosis (definitivos y probables), 48 (40 por ciento) con cáncer, 3 (2.5 por ciento) con colagenosis, 1 (0.8 por ciento) con linfangioleiomiomatosis y 13 (11 por ciento) sin diagnóstico. La sensibilidad de los cultivos, en el grupo con diagnóstico definitivo de tuberculosis, fue de 60 por ciento (17 de 28) para líquido pleural, 50 por ciento (14 de 28) para la biopsia, 16 por ciento (1 de 6) para el esputo, 14 por ciento (1 de 7) para el lavado gástrico; el ZN de la biopsia representó una sensibilidad del 35 por ciento (10 de 28), resultados similares a los informados en la literatura, excepción hecha del cultivo de la biopsia que fue ligeramente menor y el Zn de la biopsia que fue sensiblemente mayor. El rendimiento de la histología en los que egresaron con diagnóstico de tuberculosis, independiente del número de biopsia fue del 88 por ciento, superior al descrito en la literatura. En los pacientes con tuberculosis definitiva, el bloque celular sugestivo de la misma presentó una sensibilidad de 84 por ciento, especificida de 94 por ciento, valor predictivo positivo de 91 por ciento y negativo del 89 por ciento; en el mismo grupo de pacientes la prueba cutánea de la tuberculina dio una sensibilidad de 31 por ciento, con especificidad de 81 por ciento, valor predictivo positivo de 66.6 por ciento y negativo del 78 por ciento

Relationships between pleural fluid pH, PCO2 to pleural fluid PO2, amylase, protein, glucose and white cells in tuberculous and malignant effusions.

The relationships between pleural fluid pH and PO2 to pleural fluid PO2, amylase, protein, glucose, white cell count were examined in 110 cases of tuberculous and 140 cases of malignant pleural effusions. Pleural fluid amylase concentrations of 200 or more units/ml indicated malignant effusions rather than tuberculous effusions with a specificity of 92.7 per cent and sensitivity of 27.1 per cent. There was evidence which suggested that the increasing pleural fluid amylase concentrations were due to the excessive leakage of serum amylase into the pleural cavity secondary to the break-down of capillaries by tuberculosis and malignancy as well as the production of amylase by tumor cells invading the pleura. The decreasing pleural fluid pH and increasing pleural fluid PCO2 had a significant linear relationship with decreasing fluid PO2, increasing pleural fluid protein and decreasing fluid glucose. These indicated a leakage of serum protein into the pleural cavity and the over-utilization of glucose relative to the transport defect of low pleural fluid glucose concentrations in the acidotic fluid of tuberculous and malignant effusions. No relationship between pleural fluid pH and PCO2 to pleural fluid and white cell count was found in the present study.

Determinación de adenosindeaminasa (ADA) en líquido pleural: utilidad en el diagnóstico de tuberculosis pleural / Determination of adenosine-deaminase (ADA) in pleural fluid: its usefulness in the diagnosis of pleural tuberculosis

Las técnicas utilizadas en el diagnóstico de la tuberculosis pleural tienen un rendimiento limitado (pesquisa de bacilo de Koch 10% y biopsia pleural 60%) La adenosin-deaminasa aumenta significativamente en los derrames pleurales tuberculosos y en los empiemas y, en menor escala, en los derrames de naturaleza neoplásica y en los paraneumónicos. Se determina la concentración de adenosin-deaminasa en el líquido pleural de 62 pacientes con derrames. Se encuentran valores muy elevados en los empiemas y en los derrames tuberculosos, moderados en los neoplásicos paraneumónicos y normales en los transudados. El procedimiento es sospechoso de tuberculosis pleural cuando revela niveles de adenosoin-deaminasa comprencdidos entre 40 y 70 unidades por litro y practicamente seguro cuando sobrepasan de 70 unidades. En el presente trabajo el examen demostró una sensibilidad de 100% y una especificidad de 80%

Análise das fraçöes de desidrogenase lática (DHL) no líquido pleural / Analysis of lactic dehydrogenase fractions in the pleural effusion

Com o objetivo de avaliar a utilidade da determinaçäo da distribuiçäo porcentual das isoenzimas da desidrogenase lática no líquido pleural, foram estudados 26 pacientes com idade de 48 a 83 anos (média 63,5 anos). Seis eram portadores de derrame pleural por insuficiência cardíaca, seis por neoplasia, cinco após revascularizaçäo do miocárdio, dois por empiema, três por tuberculose e quatro idiopáticos. Os líquidos pleurais foram classificados em cinco tipos, de acordo com a classificaçäo de Vergon. Tipo I - samatória das isoenzimas 1,2 e 3 maior que 70%. Tipo II - semelhante ao I com isoenzima 5 maior que 15%. Tipo III - somatória das isoenzimas 4 e 5 maior que 60%. Tipo IV - aumento progressivo das isoenzimas de 1 a 5; Tipo V - distribuiçäo equitativa das isoenzimas. Cinco pacientes com insuficiência cardíaca foram classificados no tipo I e um no tipo V. As neoplasias de distribuíram nos tipos I (2), III (1), IV (1) e V (2). Dois derrames pós-revascularizaçäo encontraram-se no tipo I, e no IV e 1 no V. Os pacientes com empiema foram classificados como tipo IV. Os derrames tuberculosos distribuíram-se nos tipos I)1), IV(1) e V(1). Quanto aos idiopáticos, um caso encontrou-se no tipo III e três no V. A análise isolada do DHL5 revelou estar esta isoenzima elevada nos quatro casos de neoplasia em que o derrame foi hemorrágico. O mesmo achado se encontrou em pós revascularizaçäo e no empiema. Concluímos que a análise das fraçöes da DHL näo foi útil como marcador de neoplasia

Adenosin Deaminasa (ADA) en líquido pleural: valor para la identificacion de la etiologia tuberculosa / Adenosina deaminase (ADA) in pleural fluid: value for the identification of tuberculous etiology

La concentración de adenosin deaminasa (ADA) en el líquido pleural se encuentra elevada en los derrames por tuberculosis, empiema, artritis reumatoidea y enfermedades linfoproliferativas, siendo sus niveles cercanos a los del plasma normal en las neoplasias, derrames para-neumónicos y transudados. Dado que los valores de tuberculosis se superponen con los de las neoplasia en grado diferente en las distintas publicaciones, no existe acuerdo respecto al nivel discrimnatorio entre estas patologías. Con el objeto de valorar este método en nuestro medio y definir un criterio diagnóstico, se determinó la concentración de ADA en el líquido pleural de 107 pacietnes consecutivos con diagnóstico comprobad. Al igual que en la literatura se observó un grupo con ADA promedio elevada (TBC 82.2 U/L ñ 26,3 DS; empiema 85,0 U/L ñ 85; artritis reumatóidea 81,8 U/L), y otro con un nivel bajo (neoplasias 23,5 U/L ñ 17,4; paraneumónicas 15,5 U/L ñ 11,3; insuficiencia cardíaca 9,3 U/L ñ 5,5; uremia 12,9 U/L ñ 3,8 y cirrosis 8,0 U/L 2,4). Los rangos esperables en el universo de las TBC y neoplasias fueron estadísticamente inferidos y de acuerdo a ello se propone como nivel de corte inferior el de 30 U/L, bajo el cual la probabilidad de TBC es sólo 1,6% y comi nivel de corte superior el de 80 U/L, sobre el cual la probabilidad de neoplasia es de 0,6%. Se concluye que la determinación de ADA es un método aplicable en nuestro medio que contribuye al diagnóstico diferencial de los derrames pleurales