Scielo RSS <![CDATA[Revista médica de Chile]]> http://www.scielo.cl/rss.php?pid=0034-988720090002&lang=es vol. 137 num. 2 lang. es <![CDATA[SciELO Logo]]> http://www.scielo.cl/img/en/fbpelogp.gif http://www.scielo.cl <![CDATA[<b>Polimorfismo del gen de la tiopurina S-metiltransferasa en donantes de sangre de un hospital universitario</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872009000200001&lng=es&nrm=iso&tlng=es Background: Thiopurine S-methyltransferase (TPMT) is a cytosolic enzyme that catalyzes the S-methylation of 6-mercaptopurine and azathioprine. Low-activity phenotypes are correlated with polymorphism in the TPMT gene. Patients with low or undetectable TMPT activity could develop severe myelosuppression when they are treated with standard doses of thiopurine drugs. Since ethnic differences in the TPMT gen polymorphism have been demonstrated worldwide, its assessment in the Chilean population is worthwhile. Aim: To investigate the TMPT gene polymorphism in a Chilean blood donor individuals. Subjects and Methods: The frequency of four allelic variants of the TPMT gene, *2 (G238C), *3A (G460A andA719G), *3B (G460A) and *3C (A719G) were analyzedin 210 Chilean blood donors, using polymerase chain reaction (PCR), restriction fragment length polymorphism (RFLP) and allele-specific PCR-based assays. Results: TPMT variants associated to low enzymatic activity, were detected in 16 subjects (8%), who had a heterozygous genotype (*3A in 12; *3C in three and *2 in one subject). No TPMT*3B allelic variant was found. The normal allele (wild-type) was found in 92% ofstudied individuals. Conclusions: The allele TPMT*3A, is the most prevalent in this group of Chilean blood donors, as in Caucasian populations. <![CDATA[<b>Características clínicas y metabólicas de los estados de intolerancia a la glucosa y glicemia de ayuno alteradas</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872009000200002&lng=es&nrm=iso&tlng=es Background: Subjects with glucose intolerance or high fasting glucose levels have a higher cardiovascular rísk and frequently become diabetic. Aim: To assess clinical and metabolic characteristics of patients with glucose intolerance or high fasting glucose levels. Material and methods: Fasting and post glucose load serum glucose and insulin levels were measured in 1404 people, aged 42,0 ± 14,2 years (81% women) with high diabetic rísk. We categorízed subjects in different alterations of blood glucose, according to 2006 Amerícan Diabetes Association categoríes. Insulin resistance (RI), insulin secretion (B %) and insulin disposition (ID), were calculated using fasting blood glucose and insulin levels, using the homeostasis model assessment (HOMA I and II). Results: Sixty percent of studied subjects had first grade relatives with diabetes mellitus and 1097 (78%) were categorízed as normal (N), 45 (3%) as Diabetes Mellitus (DM), 161 (11%) as high fasting glucose levels (GAA) and 103 (7%) as glucose intolerant (ITG). Fifty three of the 106 subjects with GAA (50%), were also glucose intolerant. Subjects with GAA had similar insulin sensitivity and lower B cell function than N (insulin disposition 58 ± 12 and 111 ± 32%, respectively p <0.01). ITG had less insulin sensitivity than N (HOMA-IR 2.6 ± 1.50 ± and 2.0 ± 1.30, respectively) and only a mild decrease in B cell function (insulin disposition 96 ± 26 and 111 ± 32% respectively, p < 0.01). Patients GAA plus ITG had similar alterations than those with DM (HOMA-IR 3.8 ± 2.2 and 4.4 ± 3.7respectively; insulin disposition 57 ± 10 and 56.0 ± 26% respectively. Conclusions: Patients with higher fasting glucose levels behave differently from those with glucose intolerance. High fasting glucose levels are highly prevalent in subjects with high rísk of DM and must be considered as rísk indicator in preventive programs for diabetes mellitus. <![CDATA[<b>Evaluación de la calidad de vida en pacientes en hemodiálisis crónica mediante el cuestionario <i>"Kidney Disease Quality of Life (KDQOL-36)"</i></b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872009000200003&lng=es&nrm=iso&tlng=es Background: Health-related quality of life (HRQOL) among patients on chronic hemodialysis (CHD), is associated with mortality, complications and compliance to treatment. Aim: To assess HRQOL in a group of patients on CHD. Patients and methods: A cross-sectional multicenter study was carried out, involving 224 patients from five CHD units (3 prívate and 2 public) in Bio Bio Región, using the Kidney Disease Quality of Life -36 items (KDQOL-36) questionnaire and Karnofsky scale. Scores range from 0 to 100, with higher values representing a better HRQOL. Results: Physical and Mental scales and subscales of symptoms, effect and the burden of kidney disease subscales rendered scores below 50 (the referential valué), in 80%, 61%, 8%, 43% and 80% of evaluations, respectively. The lower scores were observed in patients with diabetes, coronary artery disease, hypoalbuminemia, serum creatinine below 9.4 mg/dL, age >55years and in those with a low economic and educational level (p <0.05). Conclusions: HRQOL in patients on hemodialysis had valúes below the referential score in subjects with diabetes and coronary artery disease, poor nutritional status and a low educational and socioeconomic level. The incorporation of support professionals, such as social workers, psychologists, dieticians, covering psychosocial factors, could improve the patients quality of life. <![CDATA[<b>Isla de patogenicidad de <i>Vibrio parahaemolyticus </i>en cepas chilenas clínicas y ambientales</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872009000200004&lng=es&nrm=iso&tlng=es Background: Most clinical isolates of Vibrio parahaemolyticus produce a major virulence factor known as the thermostable direct hemolysin (TDH). TDH is encoded by the tdh gene which is located in a genomic pathogenicity island (PAI). Most environmental isolates are described as tdh negative. Aim: To assess if environmental strains lack the full pathogenicity island or if only the tdh gene is deleted. Material and methods: Thirty eight clinical and 66 environmental strains of Vibrio parahaemolyticus were studied. PAI was characterized by polymerase chain reaction (PCR). The presence of tdhA and tdhS genes, was determined by Southern blot. Results: Fifty three environmental strains (80%) lacked a full PAI when compared with clinical strains. In environmental strains, Southern blot and sequence analysis showed that a genetic región of 80 kilobase pairs including genes from VPA1310 to VPA1396 was missing. Conclusions: These results highlight the genetic dynamism of Vibrio parahaemolyticus pathogenecity island región and suggest that new pathogenic strains could appear by horizontal transfer of the island between toxigenic and non-toxigenic strains. <![CDATA[<b>Influencia del nivel socioeconómico (NSE) en el asma bronquial y cambios en su prevalencia en población escolar en un periodo de 6 años</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872009000200005&lng=es&nrm=iso&tlng=es Background: Asthma prevalence is increasing worldwide, especially in developing countries. Aim: To determine the prevalence of asthma diagnosis and related symptoms in children, its changes during a 6-year period and the iníluence exerted by socioeconomic status. Materials and methods: Cross-sectional study conducted among school children of Santiago. A sample of 4,561 children aged 6-7 and 13-14 years attending public schools (central district, medium-low and low socioeconomic status) and prívate schools (eastern distrícts, high socioecomic status) were surveyed. Dependent variables were asthma diagnosis (AD), wheezing duríng the last 12 months (WHE12) and frequency of episodes of wheezing (FEW). Prevalence odds ratios were calculated using regression models, adjusted for several confounding variables. Results: AD prevalence for the group as a whole was higher in boys than in girls (13.2% and 10.8%, respectively p =0.016). Prevalence rate of AD was also higher for children aged 13-14 than 6-7 years (13.8% and 10.1%, respectively p <0.01). An inverse association was found between SES and WHE12. Higher maternal education level was associated with lower prevalence of WHE12 in both age groups and with lower prevalence of FEW in 6-7 year-old children. Paternal education level was positively associated with AD among younger children. At the central district, increasing trends of WHE12 and FEW prevalence were observed during 1994-2000 among 6-7years children. Conclusions: A significant association was observed between socioeconomic status, asthma diagnosis and symptoms in school children living in Santiago. Data support an increasing trend of asthma prevalence and severíty among 6-7 year-old children during the period 1994-2000. <![CDATA[<b>Factores de riesgo familiares asociados a la conducta suicida en adolescentes con trastorno depresivo</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872009000200006&lng=es&nrm=iso&tlng=es Background: Suicide is the second or third cause of death among Chilean teenagers aged 15 to 19 years. Aim: To evaluate familial risk factors associated to suicidal attempt in adolescents with a depressive disorder. Material and methods: Thirty two teenagers with depression, aged between 13 and 18 years, receiving psychological treatment in six public Mental Health Centers in Santiago and 32 fathers, mothers or tutors were evaluated. Beck's Depression Inventory and the Family Adaptability and Cohesión Evaluation Scale (FACES III, family versión) were applied to adolescents. Aduits were evaluated by the Goldberg's General Health Questionnaire and the FACES III parents versión. Results: No meaningful statistical association between adolescents suicidal attempt and family risk factors (family order, presence of family stressors and parent's mental health), was observed. However, there was a significant association between suicidal ideation of teenagers, their familiar adaptability and suicidal ideation of close relatives. Conclusions: Suicidal attempt in this group of teenagers was associated with familial adaptability and suicidal ideation by close relatives. Therefore close relatives must be integrated to the prevention programs for adolescents' suicide. <![CDATA[<b>Cirugía pulmonar en tuberculosis</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872009000200007&lng=es&nrm=iso&tlng=es Background: Surgical treatment for pulmonary tuberculosis is mainly ¡imited to the management of sequelae such as bronchiectasis, hemoptysis and brochopleural fistulae. Aim: To review the data of patients who underwent surgical treatment for pulmonary tuberculosis. Material and methods: Retrospective review of 33 patients aged 18 to 73 years (24 males) who underwent lung resection surgery for the management of pulmonary tuberculosis. Follow-up data were obtained from outpatient visit records and registries of the national tuberculosis program. Results: The reasons to perform surgery were the following: fifteen for hemoptysis, nine for lung destruction and nine for an active and multiresistant disease. No patient died in the postoperative period. The morbidity observed included empyema (n =5), pneumothorax (n =2), bronchopleural fístula (n =2) and hemothorax (n =2). At six months offollow up, six of the nine patients with active tuberculosis had negative acid-fast bacilli on sputum smear. Two of these patients died, one due to respiratory failure and another by an unrelated cause. Both dead patients had negative acid-fast bacilli on sputum smear. Conclusions: Surgery in pulmonary tuberculosis has a high rate of complications butmay be usefulin selectedpatients. <![CDATA[<b>Evaluación experimental de la eficiencia de una pintura repelente para arañas del género <i>Loxosceles</i></b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872009000200008&lng=es&nrm=iso&tlng=es Background: Loxoscelism is a severe reaction to the bite of the spider Loxosceles laeta. In recent years, a paint with repellent properties has been promoted in the commerce. However, there are no reports of experiments evaluating its effectiveness. Aim: To evaluate experimentally the repellent properties of a paint against Loxosceles laeta. Material and methods: Males, females and nymphs of L laeta were deposited in cockpits that allow the free displacement of the spider. Half of the cockpit was covered with repellent paint. Daily observations during one week, determined how frequently the spiders occupied the space covered with repellent paint. The experiments were run in triplícate. Results: No statistical differences in the occupancy ofspaces covered with repellent paint or not covered with it were observed for nymphs (87% and 67%, respectively), males (72% and 77%, respectively) or females (91% and 84%, respectively). Conclusions: The tested paint does not have a repellent action against the spider Loxosceles laeta. <![CDATA[<b>Aprendizaje basado en problemas multiprofesional: Estudio cualitativo desde la perspectiva de los tutores</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872009000200009&lng=es&nrm=iso&tlng=es Background: Problem based learning is a student centered learning technique that develops deductive, constructive and reasoning capacities among the students. Teachers must adapt to this paradigm of constructing rather than transmitting knowledge. Aim: To interpret the importance of tutors in problem based learning during a module of Health research and management given to medical, nursing, physical therapy, midwifery, technology and nutrition students. Material and methods: Eight teachers that participated in a module using problem based learning accepted to particípate in an in depth interview. The qualitative analysis of the textual information recorded, was performed using the ATLAS software. Results: We identiñed 662 meaning units, grouped in 29 descriptive categories, with eight emerging meta categories. The sequential and cross-generated qualitative analysis generated four domains: competence among students, competence of teachers, student-centered learning and evaluation process. Conclusions: Multiprofessional problem based learning contríbutes to the development of generic competences among future health professionals, such as multidisciplinary work, critical capacity and social skills. Teachers must shelter the students in the context of their problems and social situation. <![CDATA[<b>Alto subdiagnóstico del síndrome de piernas inquietas en la consulta ambulatoria neurológica y psiquiátrica</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872009000200010&lng=es&nrm=iso&tlng=es Background: Restless legs syndrome (RLS) is a neurological condition that is characterized by the irresistible urge to move the legs and is very common. In the last decade, much attention has been focused on RLS, given its high occurrence, underdiagnosis, and impact on quality of Ufe. Aim: To determine the frequency of RLS in a neurologic-psychiatric outpatient clinic. Patients and Methods: We interviewed patients attending a prívate neurological outpatient clinic, using a standardized validated questionnaire, and an additional phone interview to confirm diagnosis. Results: Of approximately 800 people attending the clinic, the questionnaire was answered by 238 subjects (168 females). Fifteen percent of respondents were affected by RLS and none had been diagnosed before. Most patients had a severe form that probably required treatment. Conclusions: A low awareness of RLS exists in Chile, even among specialized physicians. <![CDATA[<b>Primer trasplante de intestino en Chile</b>: <b>Caso clínico</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872009000200011&lng=es&nrm=iso&tlng=es Small bowel transplantation is associated with a patient survival at one and five years, of 80% and 63%, respectively. We repon a 36 year-old female with short bowel syndrome, subjected to the first small bowel transplantation performed in Chile. A cadaveric gran was used. Immunosuppression was achieved by means of alemtuzumab, tacrolimus, sirolimus, micofenolate mofetil and steroids. Serial endoscopies and biopsies were performed during seven months after transplantation. The most important ¡ate complications were a drug induced renal failure, infections caused by opportunistic agents and a gastrointestinal bleedingprobably induced by drugs. After 29 months of follow up, the patient is ambulatory, on oral diet only and with no evidence of graft rejection. <![CDATA[<b><i>Obesidad mórbida en una adolescente con síndrome de Prader-Willi</i></b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872009000200012&lng=es&nrm=iso&tlng=es Prader- Willi syndrome is an uncommon multisystem genetic disorder caused by defects of chromosome 15 (15qll-ql3), often due to deletions or uniparental disomy The syndrome is characterized by neonatal hypotonia, dysmorphic facial features, short stature, motor and mental disabilities, behavioral changes, hyperphagia, precocious obesity and hypogonadotropic hypogonadism. We present a 17year-old woman, with a previous genetic diagnosis of Prader-Willi syndrome and BMI of 74 Kg/m², that was admitted in anasarca, with marked cyanosis, dyspnea and oliguria. She presented high levels ofblood urea, creatinine and aminotransferases, in addition to hyperkalemia and hyperuricemia. She had been in regular use of fluoxetine during the last six months, and evolved with severe high bloodpressure and respiratory failure, which needed intensive care support. Moreover, sequéis and clear signs of recent selfinjuries were observed in her trunk, forearms and hands. The findings of morbid obesity, anasarca, self-injury, hyperuricemia and hypoxemia in Prader- Willi syndrome are emphasized.<hr/>El síndrome de Prader-Willi es un desorden multisistémico infrecuente causado por defectos genéticos del cromosoma 15 (15qll-ql3), debido a deleciones o disomía uniparental. Se caracteriza por hipotonía neonatal, dismorfias faciales, baja estatura, incapacidades motoras y mentales, problemas conductuales, hiperfagia, obesidad precoz e hipogonadismo hipogonadotrófico. Presentamos una mujer de 17 años, con IMC de 74 Kg/m² con diagnóstico genético previo del síndrome que ingresó con anasarca, intensa cianosis, disnea y oliguria. Presentaba elevación plasmática de urea, creatinina y aminotransferasas, asociadas con hiperkalemia e hiperuricemia. Había utilizado regularmente ñuoxetina durante los seis meses precedentes y evolucionó con hipertensión arterial severa e insuficiencia respiratoria, que requirieron de cuidados intensivos. Además, se constataron cicatrices y claras señales de automutilación reciente en su tronco, antebrazos y manos. Se destacan los hallazgos de obesidad mórbida, anasarca, automutilación, hiperuricemia e hipoxemia en el síndrome de Prader-Willi. <![CDATA[<b>Sarcoma histiocítico de intestino delgado</b>: <b>Reporte de un caso y revisión de la literatura</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872009000200013&lng=es&nrm=iso&tlng=es Histiocytic sarcoma (HS) is a rare malignant neoplasm of the lymphohematopoietic system, that occurs in lymph nodes, skin and at extranodal sites, particularly the gastrointestinal tract. Although it shows characteristics histoiogical and immunohistochemical features, it may be misdiagnosed. We report a 67 year-old female patient presenting with colicky abdominal pain and vomiting. A CT sean of the abdomen revealed a tumor in the ileum, that was surgically removed. On pathology, the neoplastic cells displayed large abundant eosinophilic cytoplasm, with bizarre-shaped nuclei, that expressed CD 45, CD 68 and ¡isozyme. The diagnosis of HS requires the use of a panel of immunohistochemical markers and may be supported by ultrastructural findings . <![CDATA[<b>Osteonecrosis maxilar secundaria al uso de bisfosfonatos por vía oral</b>: <b>Exposición de tres casos clínicos relacionados con alendronato</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872009000200014&lng=es&nrm=iso&tlng=es Osteonecrosis of the jaw associated to biphosphonate use is more common in cancer patients with bone metastases, that are using intravenous diphosphonates. When these drugs are used orally the risk of the complication is lower. We report 3 diabetic women aged 69, 76 and 82 years, receiving alendronate 70 mg every one week. The unveiling event was the extraction of several teeth without the use of antibiotics. All had bone pain, purulent discharge, loss of bone and halitosis. All improved five months after discontinuing alendronate. <![CDATA[<b>Nuevos tratamientos para la infección por virus de hepatitis C y el proceso de fibrosis hepática</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872009000200015&lng=es&nrm=iso&tlng=es Hepatitis C virus (HCV) infection represents a global health problem due to its evolution to hepatic cirrhosis and hepatocellular carcinoma. The viral pathogenesis and infectious processes are not yet fully understood. The development of natural viral resistance towards the host immune system represents a mayor challenge for the design of alternative therapeutic interventions and development of viral vaccines. The molecular mechanisms of hepatic fibrosis are well described. New alternatives for the treatment of patients with HCV infection and hepatic cirrhosis are under intensive research. New drugs such as viral protease inhibitors and assembly inhibitors, as well as immune modulators have been studied in clinical trials. Additional alternatives include antifibrotic drugs, which reverse the hepatic cellular damage caused by HCV infection. This review makes reference to viral infective mechanisms, molecular pathways of liver fibrosis and overviews conventional and new treatments for HCV infection and liver fibrosis. <![CDATA[<b>Perspectivas en la prevención y tratamiento farmacológico de la enfermedad de Alzheimer</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872009000200016&lng=es&nrm=iso&tlng=es The pharmacological interventions for Alzheimer disease should be based in its pathogenic mechanisms such as amyloidogenesis, tau hyperphosphorilation, disturbances in neurotransmission and changes in neuronal trophism. Other therapies derive from epidemiological observations, such as antioxidants and anti-inflammatory drugs, estrogens, statins and anti hypertensive drugs. Some life style interventions, such as changes in diet, exercise and brain stimulation could also be beneficial for the prevention of Alzheimer disease. Ongoing research on pathogenic mechanisms promises the discovery of more effective therapies. Healthy life style should always be recommended due to its benefit and lack of untoward effects. <![CDATA[<b>Biología del envejecimiento</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872009000200017&lng=es&nrm=iso&tlng=es The study of biological aging has seen a spectacularly fast progress in the last decade. Besides a better understanding and comprehension of physiological aspects, an important advance has been the identification of at least a hundred different genes which control the process of aging. Their mechanism of action falls within the expectations from a handful of theories  which attempt to provide a global explanation of the phenomenon of aging, including free radicals, cell senescence and loss of regenerative capacity through the activation of stem cells. In this review we will concentrate in these biological aspects, with a special emphasis on animal models used to study both the genetics and physiology of aging as well as experimental approaches to test the aforementioned theories. It should be emphasized that, while the emphasis is in purely biological aspects of the process, the fast pace of aging of the world's population, including Chile, needs a rapid advance also in our understanding o fits social and economic implications. <![CDATA[<b>Revisiones sistemáticas de estudios de tests diagnósticos</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872009000200018&lng=es&nrm=iso&tlng=es The study of biological aging has seen a spectacularly fast progress in the last decade. Besides a better understanding and comprehension of physiological aspects, an important advance has been the identification of at least a hundred different genes which control the process of aging. Their mechanism of action falls within the expectations from a handful of theories  which attempt to provide a global explanation of the phenomenon of aging, including free radicals, cell senescence and loss of regenerative capacity through the activation of stem cells. In this review we will concentrate in these biological aspects, with a special emphasis on animal models used to study both the genetics and physiology of aging as well as experimental approaches to test the aforementioned theories. It should be emphasized that, while the emphasis is in purely biological aspects of the process, the fast pace of aging of the world's population, including Chile, needs a rapid advance also in our understanding o fits social and economic implications. <![CDATA[<b>Análisis crítico de un artículo</b>: <b>¿Es confiable la medición de adenosin deaminasa (ADA) para el diagnóstico de derrame pleural tuberculoso?</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872009000200019&lng=es&nrm=iso&tlng=es Background: Conventional tests are not always helpful in making a diagnosis of tuberculous pleurisy. Many studies have investigated the usefulness of adenosine deaminase (ADA) in pleural fluid for the early diagnosis of tuberculous pleuresy. We conducted a metaanalysis to determine the accuracy of ADA measurements in the diagnosis of tuberculous pleurisy. Methods: After a systematic review of English ¡anguage studies, sensitivity, speciñcity and other measures of accuracy of ADA concentration in the diagnosis of pleural effusion were pooled using random effects models. Summary receiver operating characteristic curves were used to summarize overall test performance. Results: Sixty-three studies met our inclusión criteria. The summary estimates for ADA in the diagnosis of tuberculous pleurisy in the studies included were sensitivity 0.92 (95% confidence interval 0.90-0.93), speciñcity 0.90 (95% confidence interval 0.89-0.91), positive likelihood ratio 9.03 (95% confidence interval 7.19-11.35), negative likelihood ratio 0.10 (95% confidence interval 0.07-0.14), and diagnostic odds ratio 110.08 (95% confidence interval 69.96-173.20). Conclusions: ADA determination is a relative sensitive and speciñc test for the diagnosis of tuberculous pleurisy. Measurement of ADA in pleural effusion is thus likely to be a useful diagnostic tool for tuberculous plerisy. The results of ADA assays should be interpreted in parallel with clinical findings and the results of conventional tests <![CDATA[<b>Análisis de la citación latinoamericana de la <i>Revista Médica</i><i> de Chile</i></b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872009000200020&lng=es&nrm=iso&tlng=es Background: Conventional tests are not always helpful in making a diagnosis of tuberculous pleurisy. Many studies have investigated the usefulness of adenosine deaminase (ADA) in pleural fluid for the early diagnosis of tuberculous pleuresy. We conducted a metaanalysis to determine the accuracy of ADA measurements in the diagnosis of tuberculous pleurisy. Methods: After a systematic review of English ¡anguage studies, sensitivity, speciñcity and other measures of accuracy of ADA concentration in the diagnosis of pleural effusion were pooled using random effects models. Summary receiver operating characteristic curves were used to summarize overall test performance. Results: Sixty-three studies met our inclusión criteria. The summary estimates for ADA in the diagnosis of tuberculous pleurisy in the studies included were sensitivity 0.92 (95% confidence interval 0.90-0.93), speciñcity 0.90 (95% confidence interval 0.89-0.91), positive likelihood ratio 9.03 (95% confidence interval 7.19-11.35), negative likelihood ratio 0.10 (95% confidence interval 0.07-0.14), and diagnostic odds ratio 110.08 (95% confidence interval 69.96-173.20). Conclusions: ADA determination is a relative sensitive and speciñc test for the diagnosis of tuberculous pleurisy. Measurement of ADA in pleural effusion is thus likely to be a useful diagnostic tool for tuberculous plerisy. The results of ADA assays should be interpreted in parallel with clinical findings and the results of conventional tests