Hemofilia adquirida A en embarazo. Caso clínico de medicina crítica en obstetricia por morbilidad extrema y su abordaje transdisciplinario perioperatorio / Acquired hemophilia A in pregnancy. Clinical case of critical medicine in obstetrics due to extreme morbidity and its perioperative transdisciplinary approach

Resumen: La identificación de múltiples factores de riesgo que predisponen a la hemorragia durante el evento obstétrico, como la hemofilia adquirida que es un trastorno que se desarrolla por la generación de autoanticuerpos inhibidores de factores de la coagulación, la interpretación objetiva de las pruebas de laboratorio rutinarias, el desarrollo de un pensamiento sistematizado en la integración diagnóstico-terapéutica por parte del personal de salud, y la disposición de los recursos farmacológicos hospitalarios, es lo que determina frecuentemente el pronóstico en pacientes obstétricas con morbilidad extrema que requieren atención multidisciplinaria en las diferentes unidades hospitalarias del sector salud de nuestro país. El objetivo es presentar un caso clínico de morbilidad extrema por hemofilia adquirida, su presentación clínica, evolución y desenlace fatal. Se presenta un caso referido de otra unidad del Sector Salud ISEM (Instituto de Salud del Estado de México), atendido en la Unidad de Cuidados Intensivos Obstétricos del Hospital «Mónica Pretelini Sáenz¼, resaltando la importancia en la integración diagnóstico-terapéutica y la interacción multifactorial de variables relacionadas con su desenlace fatal. Conclusiones: Desconocimiento de la patología, retraso en el diagnóstico, múltiples procedimientos condicionantes de hemorragia iatrógena y la limitación en recursos terapéuticos son factores que contribuyen a un desenlace fatal.

Abstract: The identification of multiple risk factors that predispose to bleeding during the obstetric event, such as acquired hemophilia, which is a disorder that develops due to the generation of autoantibodies that inhibit coagulation factors, the objective interpretation of routine laboratory tests , the development of systematized thinking in diagnostic-therapeutic integration by health personnel, and the provision of hospital pharmacological resources, is what frequently determines the prognosis in obstetric patients with extreme morbidity who require multidisciplinary care in the different hospital units of the health sector of our country. The objective is to present a clinical case of extreme morbidity due to acquired hemophilia, its clinical presentation, evolution and fatal outcome. A case referred from another unit of the ISEM (Instituto de Salud del Estado de México) Health Sector, treated at the Obstetric Intensive Care Unit of the «Mónica Pretelini Sáenz¼ Hospital, is presented, highlighting the importance of diagnostic-therapeutic integration, and the multifactorial interaction of variables related to its fatal outcome. Conclusions: Ignorance of the pathology, delay in diagnosis, multiple conditioning procedures of iatrogenic hemorrhage and the limitation in therapeutic resources are factors that contribute to a fatal outcome.

Manifestaciones clínicas de la deficiencia de factor XII en un lactante

RESUMEN Introducción: El factor XII o factor de Hageman pertenece al sistema de contacto al ser iniciador de la vía intrínseca de la coagulación. Concentraciones bajas de este factor se asocian a tiempo de tromboplastina parcial activado prolongado, sin embargo, no se producen manifestaciones hemorrágicas como ocurre en la deficiencia de otros factores. Objetivo: Describir las manifestaciones clínicas de un lactante con diagnóstico de deficiencia de factor XII de la coagulación. Presentación del caso: Se presenta un lactante de 10 meses que tuvo aparición espontánea de equimosis y se diagnosticó un déficit de factor XII. Conclusiones: Aunque no es común, la deficiencia del factor XII puede estar asociada a manifestaciones hemorrágicas como equimosis tal como se describe en el presente caso.

ABSTRACT Introduction: Factor XII or Hageman factor belongs to the contact system as it is the initiator of the intrinsic coagulation pathway. Low concentrations of this factor are associated with prolonged activated partial thromboplastin time, however, hemorrhagic manifestations do not occur as occurs in the deficiency of other factors. Objective: Describe the clinical manifestations of an infant diagnosed with coagulation factor XII deficiency. Case presentation: A 10-month-old infant who had spontaneous onset of ecchymosis and a factor XII deficiency was diagnosed. Conclusions: Although not common, factor XII deficiency may be associated with hemorrhagic manifestations such as ecchymosis, as described in the present case.

Actividad anticoagulante in vitro del extracto etanólico de las hojas de dos especies de la familia Euphorbiaceae / In vitro anticoagulant activity of the ethanolic extract of the leaves of two species of the family Euphorbiaceae

RESUMEN Las enfermedades cardiovasculares (ECV) son un conjunto de trastornos del corazón y de los vasos sanguíneos, que constituyen la principal causa de mortalidad en el mundo. En la búsqueda de alternativas para esta problemática, plantas medicinales de la familia Euphorbiaceae, han sido empeladas con fines terapéuticos, para prevenir, atenuar o curar los efectos generados por estas enfermedades. El objetivo de este trabajo fue conocer el perfil fitoquímico y evaluar la actividad anticoagulante in vitro de los extractos etanólicos de las hojas de Croton malambo y Acalypha hispida sobre plasma humano. Para ello, se obtuvo el extracto de las hojas y se le realizó el tamizaje fitoquímico, la evaluación del Tiempo de Tromboplastina Parcial activada (TTPa) y del Tiempo de Protombina (TP). En el perfil fitoquímico, se confirmó la presencia de alcaloides, taninos, flavonoides, leucoantocianidinas, fenoles, sesquiterpenlactonas, glucósidos cardiotónicos y terpenos. En la actividad anticoagulante, se evidenció la inhibición de la coagulación en la vía intrínseca, obteniendo resultados significativos para el TTPa, a diferencia que el test TP, donde los resultados obtenidos se encontraron similares al control. Esta investigación demuestra la acción anticoagulante de las plantas, ya que induce, significativamente, a una mayor prolongación del tiempo de coagulación; ambas especies presentaron una mayor actividad, a 200 mg/mL.

ABSTRACT Cardiovascular diseases (CVD) are a group of disorders of the heart and blood vessels, which correspond to the principal causes of death in the world. In the search for alternatives to this problem, medicinal plants of the Euphorbiaceae family have been investigated for therapeutic purposes to prevent, attenuate or cure the effects generated for these illnesses. The objective of this work was to know the phytochemical profile and evaluate the anticoagulant activity in vitro of the ethanolic extracts of the leaves of Croton malambo and Acalypha hispida on human plasma. For this, extract of their leaves was obtained, and phytochemical screening was performed, as well as the evaluation of the Activated Partial Thromboplastin Time (aPTT) and the Prothrombin Time (TP). The phytochemical profile confirmed the presence of alkaloids, tannins, flavonoids, leucoanthocyanidins, phenols, sesquiterpene lactones, cardiotonic glycosides, and terpenes. In the anticoagulant activity, the inhibition of coagulation in the intrinsic pathway was evidenced, obtaining significant results for aPTT, unlike the TP test where the results obtained were like the control. This research demonstrates the effectiveness of the plant with anticoagulant action since they significantly induce a longer prolongation of the clotting time, both species showed higher activity at 200 mg/mL.

Marcadores hematológicos y bioquímicos para el diagnóstico precoz de bacteriemiascausadas por Enterobacteriaceae resistentes a los carbapenémicos / Haematological and biochemical markers for the early diagnosis of bacteremias caused bycarbapenem-resistant Enterobacteriaceae

INTRODUCCIÓN. Las bacteriemias causadas por Enterobacteriaceae resistentes a carbapenémicos se asocian con altas tasas de mortalidad a diferencia de las bacteriemias causadas por Enterobacteriaceae sensibles a carbapenémicos. Los hallazgos clínicos y de laboratorio son importantes para determinar los esquemas terapéuticos y su pronóstico; su diagnóstico precoz resulta esencial para un manejo adecuado. OBJETIVO. Relacionar valores de marcadores sanguíneos y bioquímicos en bacteriemias causadas por Enterobacteriaceae resistentes a carbapenémicos. MATERIALES Y MÉTODOS. Estudio analítico transversal. Población de 427 y muestra de 224 datos de hemocultivos positivos para Enterobacteriaceae de pacientes atendidos en el Hospital de Especialidades Carlos Andrade Marín en el periodo mayo 2016 a julio 2018. Criterios de inclusión: i) al menos un hemocultivo positivo; ii) recuperación del aislado de CRE o CSE y iii) recolección simultanea de muestras de sangre y pruebas de laboratorio. Criterios de exclusión: i) bacteriemias polimicrobianas; ii) valores fuera de rango y iii) reportes sin valores numéricos. El análisis de datos se realizó mediante el programa estadístico International Business Machines Statistical Package for the Social Sciences versión 24.0. RESULTADOS. Se demostró que el recuento de leucocitos [OR 1,21 (95% IC: 1,03-1,43)], el recuento de plaquetas [OR 1,65 (95% IC: 1,37-1,98)] y el tiempo parcial de tromboplastina [OR 1,29 (95% IC: 1,04-1,60)] fueron buenas variables predictoras independientes, mediante análisis de regresión logística multivariante. CONCLUSIÓN. La trombocitopenia y el tiempo parcial de tromboplastina prolongado se asociaron con bacteremia causada por Enterobacteriaceae resistentes a carbapenémicos.

INTRODUCTION. Bacteremias caused by carbapenem-resistant Enterobacteriaceae are associated with high mortality rates in contrast to bacteremias caused by carbapenem-sensitive Enterobacteriaceae. Clinical and laboratory findings are important in determining therapeutic regimens and prognosis; early diagnosis is essential for appropriate management. OBJECTIVE. To relate blood and biochemical marker values in bacteremia caused by carbapenem-resistant Enterobacteriaceae. MATERIALS AND METHODS. Cross-sectional analytical study. Population of 427 and sample of 224 blood culture data positive for Enterobacteriaceae from patients attended at the Carlos Andrade Marín Specialties Hospital in the period May 2016 to July 2018. Inclusion criteria: i) at least one positive blood culture; ii) recovery of CRE or CSE isolate and iii) simultaneous collection of blood samples and laboratory tests. Exclusion criteria: i) polymicrobial bacteremia; ii) out-of-range values and iii) reports without numerical values. Data analysis was performed using the statistical program International Business Machines Statistical Package for the Social Sciences version 24.0. RESULTS. Leukocyte count [OR 1.21 (95% CI: 1.03-1.43)], platelet count [OR 1.65 (95% CI: 1.37- 1.98)] and partial thromboplastin time [OR 1.29 (95% CI: 1.04-1.60)] were shown to be good independent predictor variables, by multivariate logistic regression analysis. CONCLUSION. Thrombocytopenia and prolonged partial thromboplastin time were associated with bacteremia caused by carbapenem-resistant Enterobacteriaceae.

Hemofilia A: una enfermedad huérfana / Hemophilia A: a rare disease

La hemofilia A es una enfermedad hereditaria ligada al cromosoma X, causada por mutaciones en el gen F8 del factor VIII de la coagulación. Se considera una enfermedad huérfana, ya que su prevalencia es baja, de 26,6 por cada 100.000 nacidos vivos de sexo masculino. Los pacientes con hemofilia A tienen fases de inicio y amplificación de la coagulación relativamente normales y son capaces de formar el tapón plaquetario inicial en el lugar de la hemorragia, pero debido a la deficiencia del factor VIII, son incapaces de generar una cantidad de trombina en la superficie de las plaquetas, que sea suficiente para estabilizar el coágulo de fibrina. En un paciente masculino con hemorragias inusuales debe descartarse un trastorno de coagulación tipo hemofilia A, y se debe solicitar un recuento de plaquetas y un tiempo de protrombina (TP), los cuales usualmente son normales, y un tiempo de tromboplastina parcial activado (TPT) que se presenta prolongado. Para el diagnóstico diferencial con otras coagulopatías se realiza la medición de factores de coagulación, y pruebas de corrección cuando existe la sospecha de un inhibidor o de una hemofilia adquirida. Los pacientes afectados pueden presentar formas leves, moderadas o severas de la enfermedad, según el nivel plasmático del factor. En Colombia y en el mundo, la hemofilia fue reconocida como una enfermedad huérfana que representa un problema de salud pública, debido a su proceso de atención altamente especializado, que incrementa los costos asociados con la asistencia sanitaria, y afecta la calidad de vida de los pacientes y de aquellos que los rodean, además de que representa un reto diagnóstico que requiere constante actualización, para que pueda ser tratada de manera efectiva

Hemophilia A is an X-linked inherited disease caused by mutations in the coagulation factor VIII F8 gene. It is considered a rare disease, as its prevalence is 26.6 per 100,000 live male births. Patients with hemophilia A have a relatively normal coagulation onset and amplification phases, and are able to form the initial platelet plug at the site of hemorrhage; but due to factor VIII deficiency, they are unable to generate a sufficient amount of thrombin on the platelet surface to stabilize the fibrin clot. In a male patient with unusual bleeding, a hemophilia A-type coagulation disorder should be ruled out, and blood tests such as a platelet count and prothrombin time (PT), which are usually normal, and an activated partial thromboplastin time (APTT), which is prolonged, should be requested immediately. For differential diagnosis with other coagulopathies, measurement of coagulation factors and correction tests are performed when there is suspicion of an inhibitor or acquired hemophilia. Affected patients may present mild, moderate or severe forms of the disease, depending on the plasma level of the factor. In Colombia and worldwide, hemophilia was recognized as a rare disease that represents a public health problem due to its highly specialized care, which increases the costs associated with health care, and affects the quality of life of patients and those around them, as well as representing a diagnostic challenge that requires constant updating, so that it can be treated effectively

Hemofilia B o enfermedad de Christmas / Hemophilia B or Christmas disease

La hemofilia B o enfermedad de Christmas se diferenció por primera vez de la hemofilia A en 1947. Su forma clásica consiste en un trastorno hereditario de la coagulación causado por mutaciones en el gen F9, que codifica para el factor IX de la coagulación. Su herencia está ligada al cromosoma X; las mujeres son portadoras, pero se manifiesta clínicamente en hombres, aunque se han descrito casos de mujeres portadoras sintomáticas. El factor IX activado es una proteína dependiente de vitamina K, sintetizada en el hígado, que forma parte del complejo tenasa, cuya función es formar la mayor cantidad de trombina en el nuevo modelo de la coagulación basado en células. De acuerdo a la actividad del factor IX, su deficiencia se puede clasificar en leve (5% a 40%), moderada (1% a 5%), o severa (<1%). Su diagnóstico se realiza con la presencia de un TPT alargado que corrige con plasma normal y con la determinación del nivel funcional del factor IX, y se confirma con el estudio molecular que demuestra la mutación en el gen F9. Su diagnóstico diferencial incluye otras patologías como la hemofilia A. El tratamiento con factor IX recombinante es el más utilizado en la actualidad, pero se vienen desarrollando nuevas terapias con virus adeno-asociados recombinantes que prometen mejorar la calidad de vida para algunos pacientes afectados. La profilaxis juega un papel fundamental, en particular en los casos de enfermedad moderada y severa.

Hemophilia B or Christmas disease was first differentiated from hemophilia A in 1947. Its classic form consists of an inherited bleeding disorder caused by mutations in the F9 gene, which codes for coagulation factor IX. Its inheritance is linked to the X chromosome; women are carriers, but it manifests clinically in men, although cases of symptomatic women carriers have been described. Factor IX activates a vitamin K-dependent protein, synthesized in the liver, which is part of the tenase complex whose function is to form the largest amount of thrombin (factor IIa) in the new model of cell-based coagulation. According to factor IX activity, its deficiency can be classified as mild (5% to 40%), moderate (1% to 5%), and severe (<1%). The diagnosis is made when there is a prolonged TPT that corrects with normal plasma, and by assessing the functional level of factor IX. The diagnosis is confirmed by molecular analysis that demonstrates the F9 gene mutation. Its differential diagnosis includes disorders such as hemophilia A. Treatment with recombinant factor IX is widely used, but also new therapies are being developed with recombinant adeno-associated viruses that promise to improve the quality of life for some of these patients. Prophylaxis plays an important role in cases of moderate and severe disease

Anti-Factor Xa-Based Monitoring of Unfractionated Heparin: Clinical Outcomes in a Pediatric Cohort.

OBJECTIVES: To assess clinical outcomes in children treated with unfractionated heparin and monitored using an anti-factor Xa (Anti-FXa)-based nomogram. We also sought to assess the correlation between activated partial thromboplastin time (APTT) and Anti-FXa. STUDY DESIGN: This was a single-center, observational cohort study conducted over a 20-month period that included all pediatric patients (<21 years) who received therapeutic unfractionated heparin and were monitored using an anti-FXa-based nomogram. RESULTS: In total, 95 patients met prespecified inclusion criteria, and 1098 pairs of APTT and Anti-FXa measurements were performed. The median unfractionated heparin dose required to reach therapeutic Anti-FXa goal was significantly greater in infants compared with older children (P <.0001). The median time to achieve therapeutic Anti-FXa was 10 hours (range 2-96 hours) and was significantly shorter in patients who received a bolus compared with those who did not (P = .03). Five (5.3%) major bleeding events were noted. Age, peak Anti-FXa, peak APTT, lowest platelet count, and fibrinogen were not predictive of major and clinically relevant nonmajor bleeds. Moderate correlation between the APTT and Anti-FXa (r = 0.75; 95% CI 0.72-0.77) assays was appreciated. CONCLUSIONS: Using an anti-FXa-based nomogram to monitor unfractionated heparin in children is feasible. Although moderate correlation was observed between the APTT and Anti-FXa assays, the APTT frequently overestimated heparin activity. Safety and efficacy of an Anti-FXa nomogram needs further validation.

Secondary hemostasis studies of crude venom and isolated proteins from the snake Crotalus durissus terrificus.

Among the activities triggered by Crotalus durissus terrificus snake venom, coagulation is intriguing and contradictory since the venom contains both coagulant and anticoagulant precursor proteins. This work describes the in vitro effects of crude venom and purified proteins from snake Crotalus durissus terrificus as they affect coagulation factors of clotting pathways. Coagulant and/or anticoagulant activities of crude venom, and purified proteins were all analyzed directly in human plasma. Clots formed by crude venom and Gyroxin presented as flexible hyaline masses in punctiform distribution. Clot formation time evaluation of isolated proteins with PT and APTT assays made it possible to infer that these proteins interfere in all coagulation pathways. However, regarding ophidism by C. d. terrificus, Gyroxin acts directly, breaking down fibrinogen to fibrin and increasing the amount plasminogen activator, which results in the formation of thrombi. Crotoxin complex, Crotoxin A and Crotoxin B proteins can act in prothrombinase complex formation; Crotoxin B can inhibit prothrombinase complex formation by direct interaction with Factor Xa. Crotamine interacts with negatively charged regions of differing coagulation factors in all coagulation pathways, and possesses a whole set of activities causing dysfunction, activation and/or inhibition of natural anticoagulants and disturbing hemostasis.

Hemostatic profile in patients with and without postpartum hemorrhage / Perfil hemostático en pacientes con y sin hemorragia obstétrica posparto

Background: The association between coagulation profile and postpartum hemorrhage (PH) is still debated. Objective: To determine the association between hemostatic profile and PH in women with cesarean operation (CO). Methods: We included 92 patients with PH (cases) and 184 without (controls), patients were attended during 2014, at one hospital of the Instituto Mexicano del Seguro Social in Mérida, Yucatán. Demographic, clinical and laboratory data including prothrombin time (PT), activated partial thromboplastin time (aPTT), platelet count (PLC), and fibrinogen concentration were compared among cases and controls using a binary logistic regression model (LRM), from which odd ratios (OR), and 95% confidence intervals (95% CI), were obtained. Results: According to the bivariate comparison, in the LRM categorical data such as parity, any type of hypertensive comorbidity, type of anesthesia, and categorized aPTT (< 38 vs. ≥ 38 seconds), and one continuous variable (gestational age) were included. Having some hypertensive comorbidity (OR 3.55, 95% CI: 1.95-6.47), type of anesthesia (regional anesthesia, OR 0.27, 95% CI: 0.13-0.55) and aPTT (< 38 seconds, OR 0.26, 95% CI: 0.10-0.66) were all statistically significant. Categorized PT, platelet count and fibrinogen concentration, were not statistically significant. Conclusions: In this sample, having some hypertensive comorbidity increased risk of PH more than three times, while regional anesthesia and aPTT < 38 seconds reduced risk in 73% and 74%, respectively. Neither platelet count, nor fibrinogen concentration, or the PT categories modified risk of PH.

Introducción: la asociación entre el perfil hemostático y la hemorragia obstétrica posparto (HO) es controversial. Objetivo: determinar la asociación entre el perfil hemostático y la HO en pacientes con operación cesárea (OC). Métodos: se incluyeron 92 pacientes con HO (casos) y 184 sin HO (controles), atendidas durante 2014 en un hospital del Instituto Mexicano del Seguro Social de Mérida, Yucatán. Diversas variables, incluyendo la cuenta plaquetaria, el tiempo de protrombina (TP), el tiempo de tromboplastina parcial activado (TTPa) y el fibrinógeno plasmático, fueron comparadas entre casos y controles, mediante un modelo de regresión logística del que se obtuvieron razones de momios (RM) e intervalos de confianza de 95% (IC 95%). Resultados: con base en el análisis univariado se incluyeron en el modelo la paridad, comorbilidad hipertensiva (hipertensión crónica, preeclampsia, eclampsia), tipo de anestesia y el TTPa categorizado (< 38 frente a ≥ 38 segundos) y la edad gestacional (como dato continuo), resultando significativamente diferentes la presencia de comorbilidad hipertensiva (RM 3.55, IC 95%: 1.95-6.47), el tipo de anestesia (regional, RM 0.27, IC 95%: 0.13-0.55) y el TTPa (< 38 segundos, RM 0.26, IC 95%: 0.10-0.66). Conclusiones: en esta muestra, tener comorbilidad hipertensiva incrementó más de tres veces el riesgo de HO, la anestesia regional lo redujo en 73% y el TTPa < 38 segundos lo redujo en 74%. Ni el TP, ni la cuenta plaquetaria modificaron el riesgo.

Routine Coagulation Tests in Patients With Nonvalvular Atrial Fibrillation Under Dabigatran and Rivaroxaban Therapy: An Affordable and Reliable Strategy?

Dabigatran and rivaroxaban, direct oral anticoagulants (DOACs), affect coagulation tests, and knowledge of their effects is important for therapeutic monitoring. Our aim was to examine the association between DOAC levels and routine coagulation tests in patients with nonvalvular atrial fibrillation. Samples from patients receiving dabigatran (150 mg) and patients receiving rivaroxaban (20 mg) were collected 2 hours after drug intake. Direct oral anticoagulant concentrations were determined using direct Hemoclot thrombin inhibitor (HTI) assay (HTI test) and a direct Xa inhibitor (Anti Xa-Riva). The routine coagulation measured included activated partial thromboplastin time (aPTT) and prothrombin time (PT). The median plasmatic dabigatran was 128.3 ng/mL (95% confidence interval [CI]: 93.7-222.6 ng/mL). The HTI exhibited a good correlation with aPTT ( R2 = 0.74; P < .0001). The median plasmatic rivaroxaban was 223.9 ng/mL (95% CI: 212.3-238.9 ng/mL). Anti-Xa-Riva correlated with PT ( R2 = 0.69, P< .0001) and aPTT (R2 = 0.36, P < .001), but prolonged PT results were obtained, even below the rivaroxaban therapeutic range (20%). The routine coagulation tests were able to identify out of therapeutic range concentrations for dabigatran and rivaroxaban. We suggest the use of these screening tests to better understand and monitor the subtherapeutic concentrations of these DOACs.

Influência do tempo de centrifugação em testes de coagulação: tempo de protrombina e tempo de tromboplastina parcial / Influence of the centrifuge time in coagulation tests: prothrombin time and partial thromboplastin time

Objetivo: Analisar os testes de coagulação: tempo de protrombina (TP) e tempo de tromboplastina parcial (TTP) em diferentes tempos de centrifugação da amostra da biológica, com relação ao protocolo padrão do Clinical Laboratory Standards Institute (CLSI). Métodos: As amostras foram divididas em cinco alíquotas de 1 mL. Foi realizada a centrifugação em 15, 10, 5, 2 e 1 minuto, com velocidade de 1500 g. O TP e TTP foram imediatamente analisados em aparelho automatizado. Os plasmas foram analisados para presença de elementos residuais: eritrócitos, leucócitos e plaquetas. Resultados: Observou-se alteração dos valores do TP nos tempos de centrifugação 10, 5, 2 e 1 minuto e do TTP em 5, 2 e 1 minuto, com relação ao protocolo padrão. Na interpretação de Bland Altman, observou-se um viés significativo do limite clínico aceitável para o TP e para o TTP em todos os tempos de centrifugação, com relação ao protocolo padrão. Apenas no tempo de centrifugação de 15 minutos não foram encontradas células residuais nas amostras analisadas. Conclusão: O tempo de centrifugação de 15 minutos é o ideal para remoção completa das células sanguíneas residuais e para garantia da confiabilidade dos resultados dos testes de coagulação TP e TTP.

Objective: To analyze the coagulation tests: prothrombin test (PT) and partial thromboplastin time (PTT) in different centrifugation times of the sample, in relation to the standard protocol of the Clinical Laboratory Standards Institute (CLSI). Methods: The selected samples were splitted up into five aliquots of 1 mL. Centrifugation of these aliquots was carried out at 15, 10, 5, 2 and 1 minute at 1500 g. The PT and PTT were analyzed in an automated apparatus. The plasmas were analyzed for presence of residual elements: erythrocytes, leukocytes and platelets. Results: The results showed a change in the values of PT at the 10, 5, 2 and 1 minute centrifugation times and the PTT at 5, 2 and 1 minutes, relative to the standard protocol. In the interpretation of Bland Altman, a significant bias of the acceptable clinical limit for TP and TTP at all centrifugation times was observed, relative to the standard protocol. Only in the 15 minute centrifugation time no residual cells were found in the analyzed samples. Conclusion: The present study demonstrated that the 15-minute centrifugation time is ideal for complete removal of residual blood cells and to ensure the reliability of the results of the PT and PTT coagulation

Determination of reference ranges for coagulation tests in Mexican-mestizo population / Determinación de límites de referencia de pruebas de coagulación en población mestizo-mexicana

Background: It is necessary to establish biological parameters for each population. Objective: To establish reference values for prothrombin time (PT), activated partial thromboplastin time (PTT) and fibrinogen in healthy population and to determine intra- and inter-assay concordance. Methods: Cross-sectional study that included 204 women and 202 men from the Blood Donor service. Coagulation tests were carried out in order to obtain reference ranges. All procedures were made according to the Clinical & Laboratory Standards Institute guidelines. Results: Mean PT, PTT and fibrinogen were 14.1 s, 28.8 s and 381 mg/dL in men, and 15.1 s, 29.0 s and 381 mg/dL in women. The proposed PT, PTT and fibrinogen reference ranges for men were 12.7 to 16.3 s, 24.2 to 36.3 s and 239 to 276 mg/dL, respectively; for women, 12.7 to 16.6 s, 23.5 to 35.4 s and 276 to 598 mg/dL. The latter was statistically significant (p ≤ 0.001). Conclusions: Reference values for blood coagulation tests were determined. This is of great importance for fast medical diagnosis and treatment. The results from this study can be adopted by other clinic laboratories after appropriate validation procedures.

Introducción: Es necesario establecer valores de referencia biológicos para cada población. Objetivo: Establecer los límites de referencia de tiempo de protrombina (TP), tiempo parcial de tromboplastina (TTP) y fibrinógeno en población mestizo-mexicana sana, así como la correlación y la concordancia en la determinación de estas pruebas con los dos equipos utilizados. Métodos: Estudio transversal en 204 mujeres y 202 hombres que acudieron al servicio de donadores y se les determinó TP, TTP y fibrinógeno para obtener los límites de referencia. Los procedimientos se realizaron de acuerdo con las guías del Instituto de Estándares de Laboratorio y Clínicos (CLSI C28-A3). Resultados: La media de TP, TTP y fibrinógeno en hombres fue de 14.1 s, 28.8 s y 381 mg/dL, y en mujeres de 15.1 s, 29.0 s y 381 mg/dL, respectivamente. Los límites de referencia para hombres en TP, TTP y fibrinógeno fueron de 12.7 a 16.3 s, de 24.2 a 36.3 s y de 239 a 276 mg/dL; para mujeres de 12.7 a 16.6 s, de 23.5 a 35.4 s y de 276 a 598 mg/dL, respectivamente. Este último fue estadísticamente significativo (p ≤ 0.001). Conclusiones: Se determinaron los límites de referencia para las pruebas de coagulación. Los resultados obtenidos en este estudio pueden ser adoptados por otros laboratorios clínicos, después de su apropiada validación.

A 2-year-old boy with circulatory failure owing to streptococcal toxic shock syndrome: case report.

A 2-year-old boy presented with severe hypotension and acute kidney injury after a prodrome of non-bloody diarrhoea and fever in the preceding 3 days. He had a mild Ebstein cardiac anomaly but otherwise a normal past history and growth. On examination, he looked ill, his temperature was 37.5 °C, circulation was poor, and there were several purpuric lesions on the face, hands and scrotum. Haemoglobin was 7.8 g/dL (11-14), total white cell count 27 × 109/L, platelets 62 × 109/L, blood urea nitrogen 20.7 mmol/L (4.2-17.1), serum creatinine 95.4 µmol/L (21.2-36.2), CRP 154 mg/L (<5), AST 296 U/L (11-50), ALT 909 U/L (7-40) and C3 component of complement 0.8 g/L (0.9-1.8). Activated partial thromboplastin time (APTT) and prothrombin time (PT) were prolonged and fibrinogen level was 1.0 g/L (2-4). He received immediate fluid resuscitation (IV 0.9% saline solution, 2 × 10 ml/kg boluses, followed by glucose 5/0.45% sodium chloride solution, 2 × 10 ml/kg) and antibiotics (ciprofloxacin and amikacin) but circulation continued to deteriorate with development of decreased consciousness. He was placed on mechanical ventilation and vasopressor agents were added. Despite improved circulation over the next 2 days, he developed oliguria, progressive fluid overload, generalised oedema and a right-sided pleural effusion. Dialysis was commenced on day 3 of admission. Differential diagnosis included sepsis, atypical haemolytic uraemic syndrome and lupus nephritis. Blood and urine cultures remained negative but an anti-streptolysin O titre of 1318 (<200) IU/mL led to the diagnosis of streptococcal toxic shock syndrome which is rare in early childhood and associated with high mortality. Haemodialysis was commenced and continued for 10 days with successful treatment of fluid overload and subsequent extubation. Renal function was completely restored over the following 6 weeks and he was discharged in good clinical condition about 2 months after intial admission. The clinical course and outcome are discussed, and the importance of timely initiation of dialysis when there is fluid overload is emphasised.

Comprometimento hemostático em pacientes com icterícia obstrutiva / Haemostatic impairment in patients with obstructive jaundice

A doença hepática é associada à alterações hemostáticas devido à diminuição na síntese dos fatores de coagulação. Neste sentido, objetivou-se avaliar o comprometimento da hemostasia em pacientes com icterícia obstrutiva. Os pacientes foram analisados por gênero, idade, etiologia da doença, tempo de protrombina (TP) e tempo de tromboplastina parcial (TTP) antes e após a cirurgia. A icterícia obstrutiva ocorreu com maior frequência entre as mulheres (60,0%), sendo a coledocolitíase a causa mais comum da doença (80,0%). Os valores pré-cirúrgicos do TTP estavam dentro da faixa normal. No entanto, todos os pacientes apresentaram um TP prolongado na avaliação pré-operatória. Uma redução significativa (p<0,001) foi verificada na análise pós-operatória do TP, atingindo a faixa normal em 66,7% dos pacientes estudados. Verificou-se uma correlação positiva (r = 0,813 p<0,001) entre os valores pré-operatórios do TP e a idade dos pacientes. Além disso, os valores pré-operatórios e pós-operatórios do TP foram significativamente mais elevados (p<0,05) entre pacientes com icterícia obstrutiva de etiologia tumoral. Os resultados deste estudo demonstraram uma forte correlação entre a idade dos pacientes e a atividade dos fatores de coagulação vitamina K dependentes, além de uma diminuição significativa na atividade destes fatores em pacientes com icterícia obstrutiva de etiologia tumoral.

Liver disease is associated with haemostatic abnormalities due to the decreased synthesis of the clotting factors. Therefore, this study aimed to evaluate the impairment of haemostasis in patients with obstructive jaundice. Patients were analyzed by gender, age, cause of jaundice, prothrombin time (PT) and partial thromboplastin time (PTT) before and after surgery. Obstructive jaundice occurred more commonly amongst the females (60.0%), and choledocholithiasis was the most frequent cause of the disease (80.0%). Presurgical PTT values were within the normal range, whereas all the patients showed increased PT in the preoperative evaluation. A significant decrease (p<0.001) was found in the postoperative PT measurement, reaching the normal range in 66.7% of the studied patients. A positive correlation was found between the preoperative PT values and the age of the patients (r = 0.813 p<0.001). In addition, preoperative and postoperative PT values were significantly higher (p<0.05) among the patients with obstructive jaundice of tumoral etiology. Results from this study have shown that activity of vitamin K-dependent clotting factors in obstructive jaundice was strongly correlated with subject's age and was significantly decreased in patients with tumoral etiology.

Variabilidade na sensibilidade à heparina de reagentes do TTPA em plasmas heparinizado in vitro e de pacientes heparinizados / Variability in heparin sensitivity of TTPA reagents in heparinized plasma in vitro and patients receiving heparin

Introdução: No final da década de 80 e início dos anos 90 vários estudos demonstraram a falta de padronização e a variabilidade nos resultados do TTPA devido a diferentes sensibilidades à heparina dos reagentes empregados para sua determinação. Objetivo: Avaliar a sensibilidade à heparina de reagentes utilizados para a determinação do TTPA em amostras de plasmas heparinizadas in vitro e de pacientes em uso de heparina não fracionada (HNF). Material e Métodos: Para este estudo foi utilizado um pool de plasma heparinizado, com concentrações de 0,1 até 1,0 unidade de heparina/mL, 29 pacientes em uso de HNF e 8 kits de reagentes para a determinação do TTPA. Resultados e Discussão: Com os plasmas heparinizados in vitro os resultados com o reagente da Actin® foram estatísticamente diferente dos da Labtest®, da Human® e da Clot®. O melhor coeficiente de correlação, resultado do TTPA versus concentração de HNF, foi observado com o reagente da Stago® (R=0,9919). Quando-se empregou os plasmas de pacientes em uso de HNF os resultados do Actin® e do Actin FSL® foram estatisticamente diferentes dos da Clot®. Conclusão: Diferenças estatisticamente significativas, nos valores de TTPA, ainda são observadas, tanto em plasmas de pacientes em uso de HNF como em plasmas heparinizados in vitro de acordo com o reagente utilizado.

Introduction: At the end of the 1980s and at the beginning of the 1990s, several studies showed lack of standardization and variability in APPT results due to the different sensibilities to heparin in reagents used for its determination. Objective: To evaluate the sensibility to heparin in the different reagents used to determine APPT in samples of heparinized plasma in vitro and in patients using non-fractioned heparin (NFH). Material and Methods: This study was performed with a pool of heparinized plasma with concentrations from 0.1 to 1.0 unit heparin/mL, 29 patients using NFH and 8 reagent kits for TTPA determination. Results and Discussion: Using heparinized plasma in vitro, there was a statistically significant difference with Actin® reagent in relation to Labtest®, Human® and Clot® reagents. The best correlation coefficient, a result of the APTT versus UFH concentration was observed with reagent from Stago® (R = 0.9919). When we used the plasma from patients using UFH, the results of Actin ® and Actin FSL® were statistically different from the Clot®.

Valores de Referência para tempos de coagulação em uma população de cães de Porto Alegre, RS, Brasil / Reference values for coagulation time of dogs in Porto Alegre, RS, Brazil

Background: Prothrombin time (PT) and activated partial thromboplastin time (PTT) are screening tests for coagulopathies in dogs. Both tests measure the clotting ability by the activation of different parts of the coagulation cascade. These tests vary widely in terms of reference parameters, mainly due the considerable diversity of reagents and analyzers available. In addition, there are many variations inherent to different populations, and little has been published about coagulation reference parameters for the local dog population. The main objective of the present study was to determine a clotting time reference range of a dog population in Porto Alegre, Rio Grande do Sul, Brazil.Materials, Methods & Results: Hemostatic reference range was determined from citrated plasma of 268 clinically heathy dogs of both genders. The animals did not present bleeding diathesis or thrombocytopenia history. All dogs were previously submitted to clinical examination (cardiopulmonary auscultation, abdominal palpation, and rectal temperature) and laboratory screening (complete blood count, creatinine, albumin, and alanine aminotransferase). PT and PTT of 71 and 258 samples were measured, respectively. Blood samples were collected into 2.7 mL 3.2 % sodium citrate tubes (9 parts blood : 1 part citrate) by vacuum. Blood samples were centrifuged; the plasma was harvested and stored at -30 °C upon analyses. All analyses were performed using the viscosity detection method in semi-automatic coagulometer according to manufacturers guidelines. The reference ranges were determined in accordance with the American Society for Veterinary Clinical Pathology. The PT and PTT reference ranges were between 6.06 to 9.32 s and between 15.25 to 24.57 s, respectively.Discussion: The increased activity of the extrinsic pathway clotting factor generates narrow values in the PT assay, in comparison to PTT results.[...](AU)

Valores de Referência para tempos de coagulação em uma população de cães de Porto Alegre, RS, Brasil / Reference values for coagulation time of dogs in Porto Alegre, RS, Brazil

Background: Prothrombin time (PT) and activated partial thromboplastin time (PTT) are screening tests for coagulopathies in dogs. Both tests measure the clotting ability by the activation of different parts of the coagulation cascade. These tests vary widely in terms of reference parameters, mainly due the considerable diversity of reagents and analyzers available. In addition, there are many variations inherent to different populations, and little has been published about coagulation reference parameters for the local dog population. The main objective of the present study was to determine a clotting time reference range of a dog population in Porto Alegre, Rio Grande do Sul, Brazil.Materials, Methods & Results: Hemostatic reference range was determined from citrated plasma of 268 clinically heathy dogs of both genders. The animals did not present bleeding diathesis or thrombocytopenia history. All dogs were previously submitted to clinical examination (cardiopulmonary auscultation, abdominal palpation, and rectal temperature) and laboratory screening (complete blood count, creatinine, albumin, and alanine aminotransferase). PT and PTT of 71 and 258 samples were measured, respectively. Blood samples were collected into 2.7 mL 3.2 % sodium citrate tubes (9 parts blood : 1 part citrate) by vacuum. Blood samples were centrifuged; the plasma was harvested and stored at -30 °C upon analyses. All analyses were performed using the viscosity detection method in semi-automatic coagulometer according to manufacturer’s guidelines. The reference ranges were determined in accordance with the American Society for Veterinary Clinical Pathology. The PT and PTT reference ranges were between 6.06 to 9.32 s and between 15.25 to 24.57 s, respectively.Discussion: The increased activity of the extrinsic pathway clotting factor generates narrow values in the PT assay, in comparison to PTT results.[...]

Correlación de valores de TTPa con anti factor Xa para establecer rango terapéutico en tratamiento anticoagulante con heparina sódica / Correlation between aPTT and antifactor Xa to determine therapeutic ranges for unfractionated heparin

Background: The therapeutic range (TR) of activated partial thromboplastin time (aPTT) for unfractionated heparin (UFH) dosing was established in the 1970 decade. Since then aPTT determination has changed. Current TR may be sub or supra-therapeutic depending on the reagents of the test, and therefore, responsible for complications of therapy. Aim: To establish the TR for UFH dosing in our institution using antifactor Xa analysis as reference standard. Material and Methods: After obtaining an informed consent, 43 blood samples were obtained for aPTT determination and antifactor Xa assay in 23 patients treated with intravenous UFH. Samples were processed at Emergency and Hemostasis Labs. We excluded patients receiving other anticoagulants, with thrombophilia, pregnancy or liver disease. Results: Mean aPTT values in the Hemostasis and Emergency labs ​​were 57.1 ± 18.9 and 56.6 ± 18.3 seconds, respectively (p = 0.77). The squared correlation coefficients between aPTT and antifactor Xa at hemostasis and emergency labs were R2 0.5 and 0.45 respectively, p < 0.001. Using a linear regression analysis, therapeutic aPTT range values ​​in our laboratory were established between 50 and 80 seconds, corresponding to antifactor Xa values of 0.3 to 0.7 IU/mL. Conclusions: According to current recommendations, validation of aPTT determination with reference techniques should be done in every institution.

Transmission of lupus anticoagulant by allogeneic stem cell transplantation.

Passive transmission of autoimmune diseases by allogeneic stem cell transplantation is rare and is ascribed to passive transfer of memory B-cells from donor to recipient. We hereby report a case of transmission of an asymptomatic lupus anticoagulant from a sibling donor to a recipient of transplantation for secondary acute myeloid leukemia. On pre-harvest evaluation, the sibling donor with no history of bleeding or thrombosis was found to have a lupus anticoagulant. After engraftment, the recipient was found to have a new prolonged activated partial thromboplastin time and was subsequently shown to have a lupus anticoagulant on Day +73 after stem cell transplantation. The recipient remained well with no evidence of bleeding, thrombosis, or graft-versus-host disease and was on a stable dose of tacrolimus at the time the lupus anticoagulant was detected. There was no other identifiable trigger for the appearance of a lupus anticoagulant.