Abstract Introduction: Graft-versus-host disease (GVHD) is a serious complication in allogeneic transplantation. The first-line treatment is high doses of corticosteroids. In the absence of response to corticosteroids, several immunosuppressive drugs can be used, but they entail an elevated risk of severe infections. Added to this, there are patients who do not improve on any immunosuppressive treatment, with subsequent deteriorated quality of life and high mortality. Ruxolitinib has been shown to induce responses in refractory patients. In this study we have presented our real-life experience. Methods: A retrospective analysis was performed on patients with severe GVHD refractory to corticosteroids. Demographic, previous treatment, response and mortality data were collected. Results: Since 2014, seventeen patients with GVHD were treated with ruxolitinib due to refractoriness to corticosteroids and immunosuppressants and a few to extracorporeal photopheresis, 8 with acute GVHD (1 pulmonary, 4 cutaneous grade IV and 3 digestive grade IV) and 9 with chronic GHVD (5 cutaneous sclerodermiform, 2 pulmonary and 1 multisystemic). The overall response to ruxolitinib treatment for acute GVHD was 80%, 40% with partial response and 40% with complete remission. Global response in chronic GVHD was 79%. The GVHD mortality was only seen in acute disease and was 40%. Causes of mortality in those patients were severe viral pneumonia, post-transplantation hemophagocytic syndrome and meningeal GVHD refractory to ruxolitinib. Conclusions: In our series, the use of ruxolitinib as a rescue strategy in acute or chronic GVHD was satisfactory. Ruxolitinib treatment in patients with a very poor prognosis showed encouraging results. However, the GVHD mortality remains high in refractory patients, showing that better therapeutic strategies are needed.

Background: In our country, transplantation centers differ in the age limit for allogeneic hematopoietic transplantation (ALOHT). In our program, transplants with age- adjusted conditioning are performed in patients until 70 years old. Currently more than 60% of ALOHT reported to the Center for International Bone Marrow Transplantation Research (CIBMTR) are performed in patients older than 40 years. Aim: To report our experience with ALOHT in acute myelogenous leukemia (AML), analyzing patient age at transplantation in different periods and transplant results in different age groups. Material and Methods: A retrospective analysis of the database of adult hematopoietic transplants in AML patients was performed. Demographic data, disease characteristics, transplant data, survival and relapse times, and mortality were collected. Results: In our program, 1030 transplants were performed in adults and 119 ALOHT were performed in AML patients, between 1990 and 2020. The median age of patients in all periods was 41 years, (range 16-69). The median age was 33 and 45 years, in the periods 1990-2000 and 2000-2020 respectively (p < 0.01). Seventy-eight patients received myeloablative conditioning (median age 44 years) and 41 reduced intensity conditioning (median age 53 years). Five-year overall survival was 44.6% (confidence intervals (CI) 41-48). Non relapse mortality of all periods was 19% (CI 17 - 40%) and relapse rate was 17 % (CI 16-22). No difference in five years overall survival among patients younger than 40, 41 to 50 and over 51 years was observed. Conclusions: Overall Survival, non-relapse mortality and relapse rate were similar in younger and older patients in our program and similar to those previously reported in other centers.

Abstract: Introduction: Screening for Autism Spectrum Disorders (ASD) using the Modified Checklist for Autism in Toddlers, Revised with Follow-up (M-CHAT-R/F) increases early detection, allowing early interventions and improving prognosis. This tool is part of the management in case of suspected ASD in several clinical guidelines. The objective of this article was to conduct the concurrent and discrimi nant validation and the reliability analysis of M-CHAT-R/F in the Chilean population. Patients and Method: This is the second stage of the cross-cultural adaptation of cross-sectional design. M-CHAT- R/F was applied to a sample of 20 children with suspected ASD and 100 randomly selected healthy control children, aged between 16-30 months. Autism Diagnostic Observation Schedule (ADOS-2), considered as reference, was applied to the 20 patients of the clinical sample, to 20 children of the healthy control sample and to those cases of the healthy control sample with M-CHAT-R/F positive. Cronbach alpha was calculated, as well as M-CHAT-R/F and ADOS-2 correlation, sensitivity, and specificity analyses. Results: In the healthy sample, M-CHAT-R/F was positive in two patients, with one of them positive and the other one negative for ASD with ADOS-2 test. In the clinical sample, M- CHAT-R/F was positive in all cases, three of them were negative in the ADOS-2 test. The Alfa relia bility of M-CHART-R/T was 0,889, the discriminant sensitivity and specificity were 100% and 98%, and the concurrent ones were 100% and 87.5% respectively. Conclusions: The Chilean M-CHAT- R/F version was reliable, sensitive and specific, similar to the original test, which opens the possibility for its use in clinical samples and for research. Validating M-CHAT-R/F is an ongoing process which must be further developed.

Resumen: Introducción: El tamizaje de los Trastornos del Espectro Autista (TEA) mediante el Modified Chec klist for Autism in Toddlers - Revised with Follow Up (M-CHAT-R/F) aumenta la detección precoz, posibilitando intervenciones tempranas y mejorando el pronóstico. Este instrumento es parte del algoritmo de manejo ante la sospecha de TEA en diversas guías clínicas. El objetivo fue realizar la validación concurrente, discriminante y el análisis de confiabilidad del M-CHAT-R/F en una pobla ción chilena. Pacientes y Método: Esta es la segunda etapa de la adaptación transcultural, de diseño transversal. Se aplicó M-CHAT-R/F a una muestra de 20 niños con sospecha de TEA y 100 niños de control sano seleccionados al azar, de 16-30 meses de edad. Se aplicó Autism Diagnostic Observation Schedule (ADOS-2), considerado como referencia, a los 20 pacientes de la muestra clínica, a 20 niños de la muestra de control sano y a aquellos casos de la muestra de control sano con M-CHAT-R/F po sitivo. Se calculó alfa de Cronbach, análisis de correlación de M-CHAT-R/F y ADOS-2 y sensibilidad y especificidad. Resultados: En el grupo de control sano, M-CHAT-R/F resultó alterado en 2 pacien tes, siendo uno positivo y otro negativo para TEA con ADOS-2. En muestra clínica el M-CHAT-R/F fue positivo en todos, con test de ADOS-2 negativo en 3 casos. La confiabilidad Alfa del M-CHAT- R/F fue =0,889, la sensibilidad y especificidad discriminante de 100 y 98% y la concurrente 100% y 87,5% respectivamente. Conclusión: M-CHAT-R/F en su versión chilena resultó fiable, sensible y específico de manera similar al original, lo cual abre la posibilidad de su utilización en población clínica y para investigación. La validación es un proceso continuo que se debe profundizar.

Abstract: Introduction: Chronic heart failure (CHF) is a complex condition associated with systemic inflammation and endothelial dysfunction (ED) whose pathogenesis is not well understood. Objective: to evaluate a possible relationship between peripheral ED markers and response to cardiac resynchronization therapy (CRT). Method: 20 patients with CHF, QRS ≥120ms and left ventricular ejection fraction (LVEF) ≤35% were studied before and 6 months post-CRT. Minnesota Living with Heart Failure Questionnaire (MLHFQ); walking test (6min-WT); 2D-echocardiography and gated perfusion SPECT at rest; ultra-sensitive C-reactive protein (us-CRP); brain natriuretic peptide (pro-BNP); circulating endothelial cells (CEC); vascular soluble adhesion (sVCAM) and intercellular adhesion molecules (sICAM); interleukin-6 (IL-6) and von Willebrand Factor (vWF) were measured in all subjects. They were classified as responders or not to CRT, according to pre-established criteria. Results: Basal means: pro-BNP 5,290 pg / ml; us-CRP 1.7 ug/mL; MLHFQ 72; 6min-WT 391 meters. The CEC and IL-6 were above normal limits. Post-CRT, 50% were responders: 11/20 improved ≥1 NYHA class and ≥10% increase in 6min-WT; MLHFQ decreased (p <0.0001); LVEF improved (p = 0.003); final systolic volume decreased (p = 0.008) and also pro-BNP (p= 0.03). In responders CEC decreased, persisting over normal limits. There were correlations between changes of pro-BNP with TM-6min and between us-PCR with MLHFQ and vWF (p≤0.004 in all). Conclusions: In CHF there is evidence of significant ED, expressed by sICAM and CEC, a sensitive peripheral biomarker that decreased 6 months post-CRT although persisting above normal limits. Other functional and inflammatory parameters were correlated in the total group, without differences between responders and non-responders.

Resumen: Introducción: La insuficiencia cardíaca crónica (ICC) es una condición compleja asociada a inflamación sistémica y a disfunción endotelial (DE) cuya patogénesis no es bien comprendida. Objetivo: Evaluar una posible relación entre marcadores de DE periférica con la respuesta a terapia de resincronización ventricular (TRV). Método: 20 pacientes con ICC, QRS ≥120ms y fracción de eyección ventricular izquierda (FEVI) ≤35% se estudiaron pre y 6 meses post-TRV con: Minnesota Living with Heart Failure Questionnaire (MLHFQ); test de marcha (TM-6min); Ecocardiografía-2D y SPECT de perfusión gatillado en reposo; proteína C-reactiva ultra sensible (us-PCR); péptido natriurético cerebral (pro-BNP); células endoteliales circulantes (CEC); moléculas de adhesión soluble vascular (sVCAM) e intercelular (sICAM); interleukina-6 (IL-6) y Factor von Willebrand (FvW). Se clasificaron como respondedores o no a TRV según criterios preestablecidos. Resultados: Promedios basales: pro-BNP 5.290pg/ml; us-PCR 1,7ug/mL; MLHFQ 72; TM-6min 391 metros. Las CEC y sICAM estaban sobre límites normales. Post-TRV, el 50% fue respondedor: 11/20 mejoraron ≥1 clase NYHA y ≥10% del TM-6min; ML-HFQ disminuyó (p<0.0001); FEVI mejoró (p=0.003); volumen final sistólico disminuyó (p=0.008) y también pro-BNP (p=0.03). En los respondedores, las CEC disminuyeron, persistiendo elevadas, sobre lo normal. Existieron correlaciones entre cambios de pro-BNP con TM-6min y entre us-PCR con MLHFQ y FvW (p≤0.004 en todas). Conclusiones: En ICC existe evidencia de significativa DE, expresada por sICAM y CEC, biomarcador periférico sensible. Estas disminuyeron 6 meses post-TRV, persistiendo sobre el límite normal. Otros parámetros funcionales e inflamatorios se correlacionaron en el grupo total, sin diferencias entre grupos respondedores y no respondedores.

RESUMEN Este artículo evalúa la evolución de las Cooperativas de Ahorro y Crédito controladas por la Superintendencia de Economía Popular y Solidaria de Ecuador en el período 2000-2015. En la metodología se calculó un índice basado en los factores clave del negocio (cartera, captaciones y resultados) ajustados por inflación (año base 2007), cuyos resultados fueron aplicados a la teoría Fisher y comparados con la variación porcentual del Producto Interno Bruto. Del análisis se concluye que las Cooperativas de Ahorro y Crédito que forman parte del Sistema Financiero Popular y Solidario crecieron en términos reales el 18,18% lo que las convierte en las Instituciones Financieras de mejor desempeño en el Sistema Financiero Nacional. CLASIFICACIÓN JEL: G21, G29, E44

ASBTRACT This paper assesses the evolution of savings and credit cooperatives controlled by the Superintendence of Popular and Solidarity Economy of Ecuador in the period 2000-2015. In the methodology, an index was calculated based on the key business factors (shares, fund raising, and results) adjusted for inflation (base year 2007), whose results were applied to the Fisher theory and compared with the percentage variation of the Gross Domestic Product. The analysis concludes that the Savings and Credit Cooperatives that form part of the Popular and Solidary Financial System grew by 18.18% in real terms, making them the best performing financial institutions in the National Financial System. JEL CLASSIFICATION: G21, G29, E44

RESUMO Este artigo avalia a evolução das cooperativas de poupança e crédito controladas pela Superintendência de Economia Popular e Solidária do Equador no período 2000-2015. Na metodologia, calculou-se um índice baseado nos fatores-chave do negócio (carteira, captações e resultados) ajustados por inflação (ano-base 2007), cujos resultados foram aplicados à teoria Fisher e comparados com a variação porcentual do Produto Interno Bruto. Da análise, conclui-se que as cooperativas de poupança e crédito que fazem parte do Sistema Financeiro Popular e Solidário cresceram, em termos reais, 18,18%, o que as torna as instituições financeiras de melhor desempenho no Sistema Financeiro Nacional. CLASSIFICAÇÃO JEL: G21, G29, E44

Background: Atrial fibrillation (AF) generates a hypercoagulable state with an increased thrombin generation and raised levels of thrombin-antithrombin complexes, which results in a high risk of stroke and thromboembolism. Aim: To evaluate the anticoagulant effect of rivaroxaban by anti-Xa factor activity and its correlation with thrombin-antithrombin complexes, thrombin generation and prothrombin time in patients newly diagnosed with non-valvular AF. Patients and Methods: Prospective study in patients with indication of anticoagulation. Demographic variables, cardiovascular risk factors, CHA2DS2-VASc and HAS-BLED scores were recorded. Blood samples were taken at baseline, at 3 and 24 hours after the administration of the drug and at 30 days. Rivaroxaban levels, anti-Xa activity, prothrombin time, thrombin generation and plasma levels of thrombin-antithrombin complexes were determined. Results: We studied 20 patients aged 76.3 ± 8.0 years (60% female) with a CHA2DS2-VASc score > 2 points. The anti-Xa factor activity correlated with rivaroxaban plasma levels at 3 hours (r = 0.61, p < 0.01), at 24 hours (r = 0.85, p < 0.01) and at 30 days (r = 0.99, p < 0.01), with prothrombin time at 3 hours (r = -0.86, p = 0.019) and at 30 days (r = -0.63, p = 0.02) and with a sustained decrease in thrombin generation at 30 days of follow-up (r = -0.74, p < 0.01). There was no correlation with thrombin-antithrombin complexes (r = -0.02, p = 0.83). Conclusions: Rivaroxaban consistently inhibited the mild pro-coagulant state found in newly diagnosed non-valvular AF patients through the first 24 hours and this effect was maintained at 30 days. Plasma levels of the drug correlated with anti-Xa factor activity, thrombin generation and prothrombin time

Sézary syndrome (SS) is an unusually aggressive T- cell lymphoma characterized by the triad of erythroderma, the presence of more than 1,000 Sézary cells in peripheral blood and lymphadenopathies. It is accompanied by generalized pruritus and poor quality of life. The management of SS depends on its stage, patient comorbidities, and treatment availability. Extracorporeal photopheresis (ECP) is the first line of treatment for patients with T-cell lymphomas in stage IVA1, IVA2 or SS. This treatment comprises three phases: leukapheresis, photoactivation and subsequent reinfusion of lymphocytes. As it is an immunomodulatory therapy it does not produce generalized immunosuppression. We report a 76 year-old male with SS stage IIIb initially treated with 12 sessions of ultraviolet phototherapy without response. After 10 well-tolerated sessions of ECP, itching and skin lesions eventually disappeared.

Background: Chronic cocaine users develop multiple potentially lethal ischemic vascular complications associated with accelerated atherosclerosis. Aim: To assess biochemical and lipid profiles among cocaine dependent subjects in recent abstinence. Material and Methods: A blood sample to measure blood count, biochemical and lipid profiles was obtained from 78 patients aged 19 to 53 years (78% males) who complied with DSM-IV criteria for cocaine dependency. Laboratory results were compared with a group of normal subjects. Results: All cases had positive urinary cocaine, with a mean consumption lapse of 7.6 years. The frequency of smoking was higher in cases. Dependent males had higher body mass index than controls. Compared to controls, dependent females had significantly higher triglyceride (TG) levels and lower HDL cholesterol. Therefore the relation total/HDL cholesterol was higher (p = 0.0365). Dependent males had higher TG levels than their normal counterparts. Dependent subjects consuming cocaine base-paste had higher TG levels. Total proteins, albumin, urea and blood urea nitrogen were lower in dependent subjects. Among males, serum creatinine was lower and blood urea was positively correlated with the daily amount of cocaine use (p = 0.03). After a month of strict abstinence, lipid profile was repeated in 27 patients and remained unchanged. Conclusions: Chronic cocaine use was associated with higher TG in both genders and lower HDL cholesterol in women when compared with a group of healthy counterparts.

Background: Cocaine abuse is associated with an increased risk of cardiac and cerebrovascular events, such as myocardial infarction, sudden cardiac death, and ischemic stroke. The underlying mechanisms leading to these complications are not fully understood although intravascular thrombus formation and accelerated atherosclerosis are prominent findings. We report a 39-year-old male addicted to cocaine, who presented with three consecutive ischemic events characterized by an acute myocardial infarction and two ischemic strokes complicated by cardiac failure and severe neurological sequelae. The pathophysiology of cocaine-induce vascular damage and the management of the ischemic complications are discussed.

Thromboembolic disease (TED) is the leading cause of morbidity and mortality worldwide. The hallmark of oral long-term anticoagulant therapy has been the use of vitamin K antagonists, whose anticoagulant effect is exerted inhibiting vitamin K epoxide reductase. Warfarin and acenocoumarol are the most commonly used. In the last five years several new drugs for long term anticoagulation have been developed, which can inhibit single clotting factors with the purpose of improving drug therapeutic range and, ideally, minimizing bleeding risks. This review addresses the state of the art on the clinical use of inhibitors of activated factor X and thrombin.

Background: chronic cocaine users have an increased risk of developing myocardial infarction, angina, sudden death and stroke. Although the pathogenesis of this effect is not completely known, premature atheromatosis and intravascular thrombosis appear to be involved. Aim: to provide evidence for the presence of endothelial damage and activation of the haemostatic system in chronic cocaine users. Methods: 23 subjects (19males, overall mean age 32) with DSM-IV criteria for cocaine dependency and exposure to the drug within 72 hours were studied. Endothelial dysfunction was determined by circulating endothelial cell counts (CEC) and sICAM levels. Thrombin-antithrombin complexes (TAT) and thrombin generation were used to characterize haemostatic status. In vitro, platelet activation was studied by NAP-2 and RANTES. EC in culture (HUVEC) were exposed to plasma from cocaine users and controls. Von Willebrand factor was measured in the culture media as well as its expression along with that of tissue factor in EC. Platelet adhesion was evaluated by microscopy. Results: Compared to controls, EC were significantly increased in cocaine users (63±28 vs. 7±5 cells per mL, p<0. 0001). Respective sICAM levels were 360±92 vs. 261 ±34 ng/mL (p<0. 01). Similarly TAT were 2. 7±0. 7 and 0. 7±0. 4µg/L, (p<0. 06). Similar findings were obtained for NAP (129±8. 4 vs. 87. 1 ±8. 6 ng/mL) and RANTES (4. 01 ±2. 12 vs. 2. 12±0. 35 ng/L) (p<0. 01). Plasma from cocaine users induced an increased liberation of vW factor from HUVEC compared to control (5. 64±4. 0 vs. 1. 4±0. 8 UI/dL; p ≤ 0. 001). HUVEC exposed to plasma from cocaine users expressed more FT and vW factor and had a greater capacity to induce platelet adhesion. Conclusion: endothelial dysfunction and activation of the haemostatic system is observed in cocaine users. Along with the observed in vitro effect of plasma from cocaine users upon EC, these results suggest a significant role of athero-thrombosis in the vascular damage associated to cocaine use.

Antecedentes: Usuarios crónicos de cocaína tienen riesgo aumentado de presentar infarto de miocardio, angina, muerte súbita y accidentes cerebrovasculares. Aunque la patogenia del daño vascular es mayormente desconocida, se ha encontrado arterieesclerosis prematura y formación de trombos intravasculares. Objetivo: Demostrar evidencia de daño endotelial y activación del sistema hemostático en usuarios crónicos de cocaína. Métodos: Un grupo de 23 pacientes con criterios de dependencia a cocaína DSM-IV; 19 hombres (edad promedio 32 a), con exposición a la droga dentro de 72 h del estudio. Disfunción endotelial se evaluó por enumeración de las células endoteliales circulantes (CEC) y nivel de sICAM . Para activación del sistema hemostático se incluyó: complejos trombina-antitrombina (TAT) y generación de trombina; NAP-2 y RANTES para activación plaquetaria. In vitro, CE en cultivo (HUVEC), se expusieron a plasma de consumidores o controles. Se midió factor von Willebrand (FVW) en el medio y expresión de FvW y factor tisú lar (FT) sobre las CE. adhesion plaquetaria estática se evaluó por microscopía. Resultados: En usuarios de cocaína, con respecto a controles, las CEC estaban significativamente elevadas (63±28 vs 7±5 células/mL; p<0. 0001), así como los niveles plasmáticos de sICAM (360±92 vs 261 ±34 ng/mL, respectivamente; p<0. 01). TAT en pacientes y controles fueron 2. 7±0. 7 y 0. 7±0. 4µg/L; p<0. 06). NAP-2 (129±8. 4 ng/mL) y RANTES (4. 01 ±2. 12 ng/mL) significativamente aumentados comparados con controles (87. 1 ±8. 6 añd 2. 12±0. 35, respectivamente; p< 0. 01). El plasma de usuarios de cocaína indujo mayor liberación de FVW desde las HUVEC comparado con plasma control (5. 64±4. 0 vs 1. 4±0. 8 UI/dL; p ≤ 0. 001). Las HUVEC expuestas a estos mismos plasmas, mostraron aumento significativo en la expresión de FT, FVW y mayor capacidad de adherir plaquetas. Conclusiones: Consumidores crónicos de cocaína evidencian disfunción endotelial y activación del sistema hemostático. En conjunto con las observaciones in vitro del efecto de los plasmas sobre las CE, estos resultados sugieren que la aterotrombosis puede jugar un papel importante en la patogenia del daño vascular asociado al uso de cocaína.

Background: Plasmapheresis is a therapeutic alternative for diseases in which a "humoral factor" has pathogenetic relevance. However it is not devoid of adverse effects. Aim: To review the indications, number of procedures, morbidity and clinical evolution of plasmapheresis in critical patients. Patients and Methods: A retrospective and descriptive study in four intensive care units of an University hospital. The severity of patients was evaluated with APACHE II and SOFA scores. Results: Twenty patients were studied. The most common indications of plasmapheresis were thrombotic thrombocytopenic purpura (TTP) in 50% of subjects and small vessel vasculitides in 30%. The number of procedures per patient oscillated between 2 and 14 (mean: 7.1±3.3). The registered adverse effects were hypocalcemia in 50% of patients, hypotension in 42.1%, coagulopathy in 35%, hypokalemia in 29%, rash in 20%, procedure related infections in 18% and fever in 10%. There was a significant decrease of 17±28% in prothrombin time, after the procedures. Seventy five percent of patients had a favorable evolution. Global mortality rate was 15%. All deaths occurred in patients with TTP and were attributed to the progression of the disease. No death was attributed to the procedure. The initial APACHE II and SOFA scores were 12.4±8.4 and 5.3±2.9, respectively. Both scores decreased after the procedure. Among other therapeutic measures, 15% of the patients received immunosuppressant treatment, 27% were dialyzed and 32% were mechanically ventilated. Conclusions: The most common indication of plasmapheresis was TTP. Adverse effects were frequent, however there was no procedure related mortality. The global mortality rate was 15% and all deaths occurred in patients with TTP (Rev Méd Chile 2005; 133: 1441-48)

Background: Atrial fibrillation is associated to a high risk of systemic embolism and to hypercoagulability. Aim: To evaluate the activation of the coagulation cascade through determinations of the thrombin-antithrombin complex in patients with atrial fibrillation and to correlate this data with the clinical and echocardiographic risk factors for systemic embolism. Patients and Methods: In 53 patients with atrial fibrillation plasma levels of the thrombin-antithrombin complex were determined on admission to a coronary care unit and 30 days later. Using a univariate and multiple regression analysis, the association basal thrombin-antithrombin with the duration of the arrhythmia, age over 70 years, previous use of antiplatelet agents, history of hypertension, mitral valve disease, diabetes, heart failure, previous systemic embolism, left atrial diameter and the presence of spontaneous contrast echo or thrombus in the left atrial appendage, was studied. Results: Basal thrombin-antithrombin values were 40.1±69 mg/L (Median 8.34 [3.0-47.5]) compared to 2.7±3.3 mg/L in healthy controls (p <0.001). No significant correlation was found between activation of the coagulation cascade and risk factors for systemic embolism. There were no significant differences in thrombin-antithrombin values between patients with chronic or paroxysmal atrial fibrillation (29.5±43 mg/L and 49.4±83 mg/L respectively). Mean thrombin-antithrombin values in patients under antiplatelet agents were lower than in those without treatment (17.3±43 vs 66.8±127 mg/L; p=0.018). Conclusions: The activation of the coagulation cascade in patients with atrial fibrillation was confirmed. However, no association of this activation with well known clinical and echocardiographic risk factors for systemic embolism, was found. Previous antiplatelet treatment prevented a higher activation of the coagulation cascade (Rev Méd Chile 2002; 130: 1087-94)

Large numbers of immigrants from endemic areas for Chagas' disease resided in Maule Region and transmission can occur by blood transfusion.is important evaluated the usefulness of a questionnaire for identifying Trypanosoma cruzi infected blood donors in nonendemic area. In this work participate blood donors of 7 hospitals of the Region. During the 6-month period, 1.581 blood donors were asked and their samples were analysed for T. cruzi antibodies.The effectiveness of the questionnaire was evaluated by comparing donor's answers about their risk for Chagas' disease with the result of testing with an enzyme-linked immunosorbent assay. Positives samples were confirm by: indirect immunofluorescence, and polymerase chain reaction. Only one donor was positive to Chagas' disease. This donors reported no risk factors. Therefore blood donors seropositive for T. cruzi are presente in donors population of nonendemic area without the usual identifiable risk factors

Un número importante de inmigrantes provenientes de áreas endémicas para enfermedad de Chagas viven en la VII Región. Dado que una de las formas de transmisión del Chagas es por transfusión sanguínea, es importante evaluar , en zonas no endémicas, la utilidad de una encuesta de predonación para identificar donantes de sangre infectados con Trypanosoma cruzi. En este trabajo participaron 7 hospitales de la Región, durante un período de 6 meses, 1.581 donantes de sangre fueron encuestados y sus sueros analizados para detectar la presencia de anticuerpos anti-T.cruzi. La efectividad del cuestionario empleado fue evaluada, correlacionando las respuestas a las diferentes preguntas sobre la enfermedad, con el resultado del ensayo inmunoabsorbente ligado a enzima. Las muestras positivas fueron confirmadas por: inmunofluorescencia indirecta y reacción en cadena de la polimerasa. Solamente un donante fue positivo para enfermedad de Chagas. Este dador no reportó factores de riesgo. Por lo que, donantes de sangre seropositivos y parasitémicos para T. cruzi, están presentes en la población de donantes de sangre de zonas no endémicas, sin tener los usuales factores de riesgo.