The Type of Trypanosoma Cruzi Strain (Native or Non-Native) Used as Substrate for Immunoassays Influences the Ability of Screening Asymptomatic Blood Donors.

BACKGROUND: The origin (native or non-native) of Trypanosoma cruzi strains used as substrate for immunoassays may influence their performance. OBJECTIVE: To assess the performance of an immunoassay based on a native T. cruzi strain compared to another based on non-native T. cruzi strains, in asymptomatic blood donors from Mexico. METHODS: Serum samples from a tertiary referral center were tested by both ELISA-INC9 (native) and Chagatest (non-native) assays. All reactive serum samples were further analyzed by indirect immunofluorescence. RESULTS: Sera from 1,098 asymptomatic blood donors were tested. A 4.3 and 0.7% serum reactivity prevalence was observed using ELISA-INC9 and Chagatest, respectively (kappa = 0.13; -0.11 to 0.38). Subsequently, indirect immunofluorescence analyses showed higher positivity in serum samples reactive by ELISA-INC9 compared to those reactive by Chagatest (79 vs. 62.5%; p < 0.001). Furthermore, out of the 47 positive samples by both ELISA-INC9 and indirect immunofluorescence, only four (8.5%) were reactive in Chagatest assay. Meanwhile, four (80%) out of the five positive samples by both Chagatest and indirect immunofluorescence were reactive using ELISA-INC9. CONCLUSION: Immunoassays based on a native T. cruzi strain perform better than those based on non-native strains, highlighting the need to develop and validate screening assays in accordance to endemic T. cruzi strains.

[National guidelines of diagnosis and treatment of the non-Hodgkin lymphoma]. / Guías nacionales de diagnóstico y tratamiento de linfoma no Hodgkin.

Non-Hodgkin lymphoma comprises a heterogeneous group of haematological malignancies, classified according to their clinic, anatomic-pathological features and, lately, to their molecular biomarkers. Despite the therapeutic advances, nearly half of the patients will die because of this disease. The new diagnostic tools have been the cornerstone to design recent therapy targets, which must be included in the current treatment guidelines of this sort of neoplasms by means of clinical trials and evidence-based medicine. In the face of poor diagnoses devices in most of the Mexican hospitals, we recommend the present diagnose stratification, and treatment guidelines for non-Hodgkin lymphoma, based on evidence. They include the latest and most innovative therapeutic approaches, as well as specific recommendations for hospitals with limited framework and therapy resources.

Starch and albumin mixture as replacement fluid in therapeutic plasma exchange is safe and effective.

UNLABELLED: Therapeutic plasma exchange (TPE) is an effective treatment in Myasthenia gravis (MG) and Guillain-Barré syndrome (GBS) and 5% human albumin is the replacement fluid of choice; however, it is expensive. More recently, it has been suggested that starch is a safe and cheaper choice to human albumin. OBJECTIVE: To evaluate our 5-year experience using 3% hydroxyethyl starch (HES) and 5% human albumin mixture, as replacement fluid in TPE for these diseases. MATERIALS AND METHODS: Retrospective study carried out from January 2001 through September 2006. We included those patients with MG and GBS undergoing TPE. We analyzed clinical outcome (CO) and adverse events (AE) and our results were compared with a previous study which included similar patients undergoing TPE using just 5% human albumin. RESULTS: Thirty-one procedures were carried out in 26 patients, a total of 147 TPE sessions. In the group of MG we had 57% complete responses (CR) and 86% overall response (OR) while in the group of GBS we had 40% CR and 60% OR. When we analyzed our CO with the previous study no statistical differences were found. Mean processed plasma volume (PPV) was 4.2 in MG and 5.5 in GBS. Twenty patients had AE, being hypotension and catheter dysfunction the most frequent ones, while tachycardia, hypertension and paresthesias were statistically more frequent in the HES/albumin group. CONCLUSIONS: TPE with a mixture of 3% HES and 5% human albumin is as effective and safe as 5% human albumin alone for patients with these diseases.

[Retrospective transfusional audit at the Centro Nacional de la Transfusión Sanguínea]. / Auditoría transfusional retrospectiva en el Centro Nacional de la Transfusión Sanguínea.

BACKGROUND: Prior to a blood transfusion, we should consider the risk benefit ratio. The literature shows that 18 to 57% of red blood cells, up to 96% of fresh frozen plasma and 26% of platelet concentrates are unnecessarily transfused. The goal of the present work is to know the appropriateness of transfusion at public and private health institutions supported by the Centro Nacional de la Transfusión Sanguínea. MATERIAL AND METHODS: An observational, retrospective, transverse and descriptive study was carried out by analyzing the requirements of blood products considering the patient's diagnosis, requested blood components, complete blood count, prothrombin and activated partial thromboplastin time. The therapeutic indication was considered either adequate or inadequate according to the guidelines for the transfusion therapy of blood products. Descriptive statistics for the analysis of the data were used. RESULTS: We analyzed 1,573 request forms received in year 2001. In 849 cases (55%) the indication was adequate, whereas in 724 (45%) the indication of the blood products was inadequate. CONCLUSIONS: Our results show that overtransfusion is a common practice. We propose to follow the guidelines already established for the transfusion of blood components in order to avoid iatrogenia due to overtransfusion.

Detection of West Nile virus in the Mexican blood supply.

BACKGROUND: West Nile virus (WNV) is the etiologic agent of an emerging disease in the Western Hemisphere that can be transmitted to humans by blood transfusion. WNV first appeared in the United States in 1999, in Canada in 2001, and in Mexico in 2002. The aim of this nationwide study was to determine the prevalence of WNV in blood donors in Mexico as a first step in preventing its transfusion-associated transmission. STUDY DESIGN AND METHODS: In July and August 2004, a total of 3856 fresh plasma specimens collected from each state's center for blood transfusion in 29 of 31 Mexican states were screened with an investigational WNV assay (Procleix,(R) Gen-Probe Inc. and Chiron Corp.), a nucleic acid test based on transcription-mediated amplification (TMA). Reactive specimens were confirmed with a second TMA-based test, the alternative WNV assay (Gen-Probe), and with WNV capture enzyme-linked immunosorbent assays (ELISAs) for detection of immunoglobulin M (IgM) and IgG antibodies. In addition, 3714 frozen plasma samples collected in 2002 and 2003 were similarly tested. RESULTS: One of 3856 fresh samples from an asymptomatic donor from Chihuahua was reactive by both TMA-based tests and IgM ELISA, suggesting a recently acquired infection. The observed percentage of viremic donors blood donors was 0.03 percent. Results from frozen samples were not included in the prevalence calculation and none were TMA-reactive for WNV. CONCLUSIONS: WNV is present in the Mexican blood supply and measures should be taken to reduce the risk of transfusion transmission.

Therapeutic plasma exchange in Mexico: experience from a single institution.

Information about therapeutic plasma exchange (TPE) in developing countries is lacking. We report our experience with TPE performed for different indications during a 7-year period. We reviewed all TPE procedures performed in our institution during a 7-year period. Patients were divided in four groups according to the following indications: thrombotic microangiopathies (TM), myasthenia gravis (MG), polyneuropathies (PNP), and miscellaneous indications (MI). Clinical outcome (CO) and complications were evaluated. Eighty-seven procedures were carried out in 81 patients, for a total of 376 TPE sessions. Eighty-two procedures were analyzed for CO. In the group of TM we had 65% overall response rate (ORR): 35% complete response (CR) and 30% partial response (PR). Six (28.6%) patients died in this group. In the MG group we had 90% ORR: 69% CR and 21% PR. In the PNP group we had 78% ORR: 56% CR and 22% PR. In the MI group we had 92% ORR: 59% CR and 33% PR. We observed 47 adverse reactions in 40 (46%) procedures performed in 38 (47%) patients. This represented 12.5% of sessions. We had seven major complications leading to TPE discontinuation; this represented 8% of the procedures and 1.8% of sessions. One patient (0.2%) died during TPE. Our overall results are acceptable. In the TM group our results are somewhat lower than in other published reports, but in MG and PNP our results are similar to other published reports. Our complication rate is similar to that reported by others. Careful selection of patients and protocols is crucial to achieve maximum benefit from TPE programs in countries where plasmapheresis facilities are not widely available.

Serum hyperviscosity syndrome responding to therapeutic plasmapheresis in a patient with primary Sjögren's syndrome.

Hyperviscosity syndrome is a disorder first described in patients with Waldenström's macroglobulinemia and is not commonly seen in rheumatic diseases. Its association with Sjögren's syndrome is very rare and it has been reported in very few patients. We report the case of a patient with primary Sjögren's syndrome presenting as hyperviscosity syndrome who was successfully treated with therapeutic plasma exchange.

Auditoría transfusional retrospectiva en el Centro Nacional de la Transfusión Sanguínea / Retrospective transfusional audit at the Centro Nacional de la Transfusión Sanguínea

Background. Prior to a blood transfusion, we should consider the risk benefit ratio. The literature shows that 18 to 57% of red blood cells, up to 96% of fresh frozen plasma and 26% of platelet concentrates are unnecessarily transfused. The goal of the present work is to know the appropriateness of transfusion at public and private health institutions supported by the Centro Nacional de la Transfusión Sanguínea . Material and methods. An observational, retrospective, transverse and descriptive study was carried out by analyzing the requirements of blood products considering the patient's diagnosis, requested blood components, complete blood count, prothrombin and activated partial thromboplastin time. The therapeutic indication was considered either adequate or inadequate according to the guidelines for the transfusion therapy of blood products. Descriptive statistics for the analysis of the data were used. Results. We analyzed 1,573 request forms received in year 2001. In 849 cases (55%) the indication was adequate, whereas in 724 (45%) the indication of the blood products was inadequate. Conclusions. Our results show that overtransfusion is a common practice. We propose to follow the guidelines already established for the transfusion of blood components in order to avoid iatrogenia due to overtransfusion.

Introducción. Para indicar un componente sanguíneo debe valorarse el riesgo-beneficio, pues la literatura demuestra que de 18 a 57% de las transfusiones de concentrados eritrocitarios, hasta 96% del plasma fresco congelado y 26% de los concentrados plaquetarios llegan a ser innecesarios. El objetivo del presente trabajo es conocer el apego de la transfusión a las recomendaciones, en instituciones de salud pública y privadas que son apoyadas por el Centro Nacional de la Transfusión SanguíneaMaterial y mètodos.Se realizó un estudio observacional, retrospectivo, transversal y descriptivo en el Departamento de Fraccionamiento de la Sangre del Centro Nacional de la Transfusión Sanguínea analizando las solicitudes enviadas por las instituciones de salud. Los parámetros valorados fueron: diagnóstico clínico, componentes sanguíneos solicitados, hemoglobina, hematócrito, cuenta plaquetaria, tiempos de protrombina y tromboplastina parcial activado. La indicación terapèutica se consideró adecuada o inadecuada según las recomendaciones para la terapia transfusional de sangre y sus componentes. Se utilizó estadística descriptiva para el análisis de los datos.Resultados.Se analizó una muestra de 1,573 solicitudes del 2001. En 849 (55%) fue adecuada la indicación, mientras que en 724 (45%) la indicación de los productos sanguíneos fue inadecuada.Conclusión.Los resultados obtenidos en este trabajo muestran una tendencia importante a la sobretransfusión. Se propone seguir los lineamientos establecidos para la transfusión de componentes sanguíneos y así evitar la iatrogenia asociada.

El banco de sangre como servicio de interconsulta / The blood bank as a consultation service

El presente es un trabajo prospectivo de seis meses de duración en el cual se evalúa la importancia que puede tener el banco de sangre al participar como un servicio de interconsulta en el manejo del paciente hospitalizado. Del 31 de enero al 31 de julio de 1994 se realizaron 108 interconsultas que involucraron a todos los servicios del Instituto Nacional de la Nutrición Salvador Zubirán. Estas interconsultas fueron encaminadas a auxiliar al médico a cargo de los pacientes en el abordaje diagnóstico y terapéutico de los problemas relacionados con la medicina transfusional. Las principales causas de inteconculta correspondieron a pacientes con coagulopatía, con sospecha de refractariedad a plaquetas de banco y con anticuerpos irregulares a antígenos eritrocitarios. Los padecimientos de base fueron principalmente hematológicos, quirúrgicos, hepatopatías, nefropatías y padecimientos reumáticos. Concluimos que esta actividad del banco de sangre ayuda a mejorar la calidad en el manejo transfunsional de los pacientes

Enfermedad del criador de palomas: presentación de cinco casos / Pigeon breeder's disease: report of 5 patients

En este trabajo se describen las manifestaciones clínicas y de laboratorio de cinco pacientes con la Enfermedad del Criador de Palomas, los cuales fueron diagnosticados y atendidos en nuestro Hospital en los últimos dos años. Se hace énfasis en las diferentes formas de presentación clínica, así como la importancia que tiene el estudio serológico para el diagnóstico, al demostrarse la presencia de anticuerpos precipitantes en el suelo de estos pacientes en contra de antígenos presentes en el suero y en las excretas de las palomas. En uno de los casos, tuvimos la oportunidad además de estudiar a varios de sus familiares. Clínicamente nuestros pacientes tuvieron una evolución crónica (promedio 27.4 meses) lo que sugiere exposición prolongada a los antígenos aviarios y la falta de diagnóstico oportuno. Serológicamente, en los cinco pacientes detectamos la presencia de anticuerpos precipitantes en contra de antígenos de paloma. En los familiares del caso estudiado, aunque clínicamente estaban asintomáticos, en tres de los nueve encontramos los mismos anticuerpos precipitantes, por lo que consideramos la posibilidad de que algunos factores genéticos pueden ser importantes en la expresión de la respuesta inmune humoral a los antígenos aviarios, que ocurre en esta forma de neumonitis por hipersensibilidad