Coagulation abnormalities and bleeding in pregnancy: an anesthesiologist's perspective

During pregnancy, the procoagulant activity increases (manifested by elevation in factor VII, factor VIII, factor X, and fibrinogen levels), while the anticoagulant activity decreases (characterized by reduction in fibrinolysis and protein S activity), resulting in hypercoagulation. Standard coagulation tests, such as prothrombin time or activated partial thromboplastin time, are still used despite the lack of evidence supporting its accuracy in evaluating the coagulation status of pregnant women. Thromboelastography and rotational thromboelastometry, which are used to assess the function of platelets, soluble coagulation factors, fibrinogen, and fibrinolysis, can replace standard coagulation tests. Platelet count and function and the effect of anticoagulant treatment should be assessed to determine the risk of hematoma associated with regional anesthesia. Moreover, anesthesiologists should monitor patients for postpartum hemorrhage (PPH), and attention should be paid when performing rapid coagulation tests, transfusions, and prohemostatic pharmacotherapy. Transfusion of a high ratio of plasma and platelets to red blood cells (RBCs) showed high hemostasis success and low bleeding-related mortality rates in patients with severe trauma. However, the effects of high ratios of plasma and platelets and the ratio of plasma to RBCs and platelets to RBCs in the treatment of massive PPH were not established. Intravenous tranexamic acid should be administered immediately after the onset of postpartum bleeding. Pre-emptive treatment with fibrinogen for PPH is not effective in reducing bleeding. If fibrinogen levels of less than 2 g/L are identified, 2–4 g of fibrinogen or 5–10 ml/kg cryoprecipitate should be administered.

Terapias anticoagulantes na doença renal crônica / Anticoagulant therapies in chronic renal disease

Os pacientes com doença renal crônica (DRC) têm tendências hemorrágicas e trombóticas e, por isso, a indicação de anticoagulantes é complexa nos indivíduos com fibrilação atrial (FA). A FA é a arritmia mais frequente na DRC, sendo o tromboembolismo e o ictus suas principais complicações. A introdução de novos anticoagulantes orais diretos (DOACs) tem se mostrado superior aos antagonistas da vitamina K, tanto na prevenção de tromboembolismos sistêmicos como no risco de sangramento. Contudo, devem ser prescritos com cautela nesse grupo de pacientes. Para os indivíduos com DRC e clearance renal entre 30 e 50 ml/min, as doses da dabigatrana e da rivaroxabana devem ser reduzidas, no caso de pacientes com elevado risco de sangramento, não havendo necessidade de reduzir as doses de apixabana e edoxabana. Em pacientes com clearance renal entre 15 e 29 ml/min o uso da dabigatrana é contraindicado, a rivaroxabana e a edoxabana não exigem ajuste terapêutico e a dose de apixabana deve ser ajustada. Nenhum dos DOACs é indicado em pacientes com clearance renal < 15 mg/min. Outro problema da terapêutica com os DOACs é o custo do medicamento, muito superior aos dos antagonistas da vitamina K, trazendo algumas implicações clínicas relevantes: suspensão terapêutica por restrições econômicas, que mesmo quando transitória, coloca o paciente em risco de eventos tromboembólicos devido à perda rápida de seus efeitos anticoagulantes e pela possibilidade de hipercoagulabilidade paradoxal. A maior parte da população é tratada em hospitais públicos e recebe os antagonistas de vitamina K. Por isso, enquanto a relação custo-efetividade dos DOACs não for esclarecida, a prevenção e o tratamento de pacientes com DRC e FA com os antagonistas de vitamina K estão consagrados e podem trazer benefícios para esse grupo de pacientes

Patients with chronic renal disease (CRD) have hemorrhagic and thrombotic tendencies, therefore the indication of anticoagulants is complex in individuals with atrial fibrillation (AF). AF is the most frequent arrhythmia in CRD, and thromboembolism and cerebral stroke are its main complications. The introduction of new oral anticoagulants (DOACs) has proven to be superior to vitamin K antagonists in preventing systemic thromboembolisms and bleeding risk. However, they should be prescribed with caution in this group of patients. For individuals with CRD and renal clearance between 30 and 50 ml/min, the doses of dabigatran and rivaroxaban should be reduced, in the case of patients with high risk of bleeding, and it is not necessary to reduce the doses of apixaban and edoxaban. In patients with renal clearance between 15 and 29 ml/min, the use of dabigatran is contraindicated, rivaroxaban and edoxaban do not require therapeutic adjustment, and the dose of apixaban should be adjusted. No DOACs is indicated in patients with renal clearance < 15 mg/min. Another problem with DOACs therapy is the cost of the medication, which is much higher than that of vitamin K antagonists, with some important clinical implications: therapeutic suspension due to economic restrictions, even if temporary, place the patient at risk of thromboembolic events due to the rapid loss of anticoagulant effects and the possibility of paradoxical hypercoagulability. Most of the population is treated in public hospitals, and receives vitamin K antagonists. Therefore, while the cost-effectiveness ratio of DOACs has not been clarified, prevention and treatment of patients with CRD and AF with vitamin K antagonists is consecrated, and can bring benefits for this group of patients

Homozygous missense mutation p.Val298Met of F10 gene causing hereditary coagulation factor X deficiency in a Chinese pedigree / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To identify potential mutation underlying coagulation factor X (FX) deficiency in a consanguineous Chinese pedigree.</p><p><b>METHODS</b>Prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen, FX activity (FX:C) and other coagulant parameters were determined with a one-stage clotting assay. The FX antigen (FX:Ag) was determined with an ELISA assay. All coding exons and exon-intron boundaries of the F10 gene were amplified with PCR and subjected to direct sequencing. Suspected mutation was confirmed by reverse sequencing and analyzed with CLC Genomics Workbench 7.5 software.</p><p><b>RESULTS</b>The PT and APTT in the proband were prolonged to 67.2 s and 102.9 s, respectively. Further study showed that her FX:C and FX:Ag were reduced by 1% and 8%, respectively. The PT of her father, mother, and little brother were slightly prolonged to 14.5 s, 14.4 s and 14.4 s, respectively. The FX:C and FX:Ag in her father, mother and little brother were all slightly reduced. Genetic analysis of the proband has revealed a homozygous G>A change at nucleotide 27881 in exon 8 of the F10 gene, which predicted a p.Val298Met substitution. The proband's father, mother, and little brother were all heterozygous for the p.Val298Met mutation. The proband has inherited the homozygous mutation from her parents by consanguineous marriage. Other family members were all normal. Bioinformatics analysis has indicated that this mutation may result in changes in the secondary structure of the FX protein.</p><p><b>CONCLUSION</b>A homozygous mutation g.27881G>A(p.Val298Met) of the F10 gene has been identified, which probably accounts for the low FX concentrations in this pedigree.</p>

Effect of F10 gene silencing and over-expression on cell cycle of choriocarcinoma cell line JAR and the mechanisms / 南方医科大学学报

<p><b>OBJECTIVE</b>To explore the role of F10 gene in regulating cell cycles of choriocarcinoma cells and the underlying mechanisms.</p><p><b>METHODS</b>Using untreated cells as the control, JAR cells with F10 gene silencing or stable F10 over-expression were examined for cell cycle changes by flow cytometry (FCM) and for expressions of cyclin and cyclin-dependent kinase (CDKs) with Western blotting and immunofluorescence technique.</p><p><b>RESULTS</b>JAR cells over-expressing F10 gene showed reduced duration of cell cycle compared with untreated and with cells after F10 gene silencing. In F10-over-expressing cells, Western blotting revealed significantly up-regulated expressions of cyclin A2, B1, D1, E and CDK2, 6, and 7, but not CDK4, as compared with the control cells and cells with F10 gene silencing (P<0.05), and these results were consistent with those by immunofluorescence assay.</p><p><b>CONCLUSION</b>F10 gene may accelerate cell cycle progression and promote cell proliferation by up-regulating the expressions of cyclin A2, B1, D1, E and CDK 2, 4, 6, 7 in choriocarcinoma cells.</p>

Oral Rivaroxaban Treatment for L-asparaginase-induced Deep Thrombophlebitis in Lower Extremity / 임상소아혈액종양

We are reporting our experience of oral rivaroxaban (Xarelto(R)) treatment for L-asparaginase (L-ASP)-induced deep vein thrombophlebitis in the lower extremity developed during childhood acute lymphoblastic leukemia (ALL) chemotherapy, with a brief review of the literature. A 16-year-old boy was admitted to our institution with right lower leg pain and gait difficulties. He was diagnosed with ALL and started chemotherapy protocol. He had been under a chemotherapy course of delayed intensification (DI)-1. We began antibiotics treatment for possible inflammation including cellulitis of the leg and planned an MRI scan. The MRI scan indicated thrombophlebitis of the right posterior calf deep veins. Subsequent DVT CT and coagulation profiles showed other abnormal findings. Coagulation factor assay were noted with decreased levels of multi factors; Factor II 45%, Factor IX 35.3 %, Factor X 30%, Factor XI 19%, Factor XII 22%, and anti-coagulants levels were decreased also with variant degrees; Protein C Activity 51%, Protein C Ag 54.5%, Protein S Activity 35%, Protein S Antigen, total 27.1%, Protein S Antigen, free 41.7%. Low molecular heparin (LMWH) treatment was initiated and the patient was switched to oral rivaroxaban (Xarelto(R)). After 6 weeks treatment, abnormal coagulation profiles and MRI scan showed improvement. Furthermore, the patient had no other symptoms or recurrence of thrombotic events. There was no significant adverse reaction to rivaroxaban in this patient.

Oral Rivaroxaban Treatment for L-asparaginase-induced Deep Thrombophlebitis in Lower Extremity / 임상소아혈액종양

We are reporting our experience of oral rivaroxaban (Xarelto(R)) treatment for L-asparaginase (L-ASP)-induced deep vein thrombophlebitis in the lower extremity developed during childhood acute lymphoblastic leukemia (ALL) chemotherapy, with a brief review of the literature. A 16-year-old boy was admitted to our institution with right lower leg pain and gait difficulties. He was diagnosed with ALL and started chemotherapy protocol. He had been under a chemotherapy course of delayed intensification (DI)-1. We began antibiotics treatment for possible inflammation including cellulitis of the leg and planned an MRI scan. The MRI scan indicated thrombophlebitis of the right posterior calf deep veins. Subsequent DVT CT and coagulation profiles showed other abnormal findings. Coagulation factor assay were noted with decreased levels of multi factors; Factor II 45%, Factor IX 35.3 %, Factor X 30%, Factor XI 19%, Factor XII 22%, and anti-coagulants levels were decreased also with variant degrees; Protein C Activity 51%, Protein C Ag 54.5%, Protein S Activity 35%, Protein S Antigen, total 27.1%, Protein S Antigen, free 41.7%. Low molecular heparin (LMWH) treatment was initiated and the patient was switched to oral rivaroxaban (Xarelto(R)). After 6 weeks treatment, abnormal coagulation profiles and MRI scan showed improvement. Furthermore, the patient had no other symptoms or recurrence of thrombotic events. There was no significant adverse reaction to rivaroxaban in this patient.

Relationship Between Systemic Thrombogenic or Thrombolytic Indices and Acute Increase of Spontaneous Intracerebral Hemorrhage

OBJECTIVE: The objective of this study was to determine the correlations between changes in thrombogenesis or thrombolysis related factors, and the acute increase of a spontaneous intracerebral hemorrhage (sICH). MATERIALS AND METHODS: From January 2009 to October 2011, 225 patients with sICH were admitted to our hospital within 24 hours of onset. Among them, 111 patients with hypertensive sICH were enrolled in this study. Thrombogenic or thrombolytic factors were checked at admission. The authors checked computed tomography (CT) scans at admission and followed up the next day (between 12-24 hours) or at any time when neurologic signs were aggravated. Cases in which the hematoma was enlarged more than 33% were defined as Group A and the others were defined as Group B. RESULTS: Group A included 30 patients (27%) and group B included 81 patients (73%). Factors including activated partial thromboplastin time, prothrombin time, fibrinogen, and D-dimer showed a greater increase in group A than in group B. Factors including antithrombin III, factor V, and factor X showed a greater increase in group A than in group B. CONCLUSION: Based on the results of this study, it seems that the risk of increase in hematoma size can be predicted by serum thrombogenic or thrombolytic factors at admission.

Leishmania amazonensis exhibits phosphatidylserine-dependent procoagulant activity, a process that is counteracted by sandfly saliva

Leishmania parasites expose phosphatidylserine (PS) on their surface, a process that has been associated with regulation of host's immune responses. In this study we demonstrate that PS exposure by metacyclic promastigotes of Leishmania amazonensis favours blood coagulation. L. amazonensis accelerates in vitro coagulation of human plasma. In addition, L. amazonensis supports the assembly of the prothrombinase complex, thus promoting thrombin formation. This process was reversed by annexin V which blocks PS binding sites. During blood meal, Lutzomyia longipalpis sandfly inject saliva in the bite site, which has a series of pharmacologically active compounds that inhibit blood coagulation. Since saliva and parasites are co-injected in the host during natural transmission, we evaluated the anticoagulant properties of sandfly saliva in counteracting the procoagulant activity of L. amazonensis . Lu. longipalpis saliva reverses plasma clotting promoted by promastigotes. It also inhibits thrombin formation by the prothrombinase complex assembled either in phosphatidylcholine (PC)/PS vesicles or in L. amazonensis . Sandfly saliva inhibits factor X activation by the intrinsic tenase complex assembled on PC/PS vesicles and blocks factor Xa catalytic activity. Altogether our results show that metacyclic promastigotes of L. amazonensis are procoagulant due to PS exposure. Notably, this effect is efficiently counteracted by sandfly saliva.

La importancia de la determinación del factor X activado para la anticoagulación con heparinas de bajo peso molecular: experiencia en el hospital san juan de dios, 2009-2011 (primer reporte) / The importance of the determination of factor X acivated for anticoagulation with low molecularweight heparins experience at the hospital san juan de dios. (first report) 2009-2011

La anticoagulación con heparinas de bajo peso molecular (HBPM) es una herramienta terapéutica fundamental para el tratamiento de la enfermedad tromboembólica. En el presente reporte se evidencia la importancia de cuantificar la actividad del anticuerpo antifactor X activado (Xa) para el monitoreo de la enoxaparina y analizar los grupos de pacientes en riesgo de tener niveles inferiores al terap‚utico. M‚todos: se estudiaron 34 pacientes adultos, anticoagulados con enoxaparina durante el periodo 2009-2011. Asimismo, se realizó un análisis descriptivo de las características demográficas y clínicas de todo los pacientes, en donde se indicaron las causas de la anticoagulación, la comorbilidades y el tipo de anticoagulación. Se midió la actividad anti-Xa 4 horas después de la administración de enoxaparina. Resultados: El promedio de edad de los pacientes fue de 62,3+17,7 años. Un 72,71 por ciento de los pacientes utilizaron enoxaparina como indicación para el síndrome coronario agudo. La comorbilidad más importante fue la combinación con la hipertensión arterial. El aclaramiento renal promedio fue de 62,47 ml/min, solamente tres pacientes tuvieron un aclaramiento menor a 30 ml/min; un 44,1 por ciento de los pacientes eran obesos. El 55,9 por ciento de los pacientes tuvo niveles anti-factor Xa dentro del rango terapéutico y un 35,3 por ciento tuvo valores de anti factor Xa profilácticos. Conclusión: El manejo del paciente adulto que recibe terapia anticoagulación con HBPM presenta una alta complejidad, hecho que se ve reflejado tanto a su perfil demográfico como clínico. También, se considera importante contar con la determinación del factor anti Xa para el monitoreo de HBPM para cierto grupo de pacientes vulnerables y con ello lograr el efecto deseado con esta terapia, debido a que existe un alto porcentaje de pacientes con niveles fuera del rango terapéutico.

Anticoagulation is an important therapeutic tool for patients with thromboembolic disease who receive therapy with lowmolecular weight heparins (LMWH). This report gives evidence about the importance of determining the activity of Anti-Xaactivity for monitoring enoxaparin and for identifying those patients who need this analysis based on some risk factors.Methods: We studied 34 adult patients who received enoxaparin as anticoagulation therapy during the period 2009-2011. We performed a descriptive analysis of demographic and clinical characteristics of all patients, indicating thereasons for anticoagulation, comorbidities and type of anticoagulation. We determined the anti-Xa activity 4 hours afteradministration of enoxaparin.Results: The mean age of patients was 62,3 + 17,7 years, regardless of gender. 72,7% of patients received enoxaparin astherapy for an acute coronary syndrome. The most frequent comorbidity was hypertension. The average of renal clearancewas 62,47 ml/min, only three patients had a renal clearance below 30 ml/min. 44,1% of the patients were obese. 55, 9%of patients were within therapeutic levels of anti-Xa activity and 35,3% of patients had an anti-Xa activity considered asprophylactic.Conclusion: The management of adult patients receiving anticoagulation therapy with LMWH is complex and it isreflected in their demographic and clinical characteristics. It is important to determine Anti-Xa activity to monitor the useof enoxaparin as anticoagulant therapy because of the high variability found in certain groups of patients.

In vitro effects of hemocoagulase atrix and its effective components on blood coagulation of patients with bleeding disorders / 中国实验血液学杂志

This study was aimed to investigate the pro coagulation effects of hemocoagulase atrix and its effective components (batroxobin and factor X activator) on plasma of normal subjects and patients with bleeding disorders and their mechanisms. Activated partial thromboplastin time (APTT) and prothrombin time (PT) were measured. The factor (F)X activation and thrombin generation were analyzed by using chromogenic substrate method. The results showed that the plasma APTT of normal subjects was shortened by hemocoagulase atrix, batroxobin and FX activator, and the effect of FX activator was found to be concentration-dependent (r = 0.889, P < 0.05). The prolonged APTT of plasma from patients with bleeding disorders could be corrected by hemocoagulase atrix, batroxobin and FX activator, but PT showed no great changes resulted from the treatments. FX activator could promote FX activation and thrombin generation, while neither hemocoagulase atrix nor batroxobin showed such abilities. It is concluded that hemocoagulase atrix promotes coagulation process, and corrects coagulation abnormalities in patients with bleeding disorders, its main component batroxobin directly acts on fibrinogen, and FX activator promotes thrombin generation through activating FX.

Humanized monoclonal antibody TNT-3-mediated truncated tissue factor for the treatment of H22 hepatoma-bearing mice / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the inhibitory effects of humanized monoclonal antibody-3 (huTNT-3) mediated truncated tissue factor (tTF) on the H(22) hepatoma-bearing mice, and to explore its mechanisms.</p><p><b>METHODS</b>The coagulation activity of the huTNT-3/tTF fusion protein was detected by clotting assay and clotting factor X (FX) activation test in vitro. Mouse hepatoma cell line H(22) cells were inoculated subcutaneously into mice to establish the mouse models of hepatoma. The mice were randomly divided into two groups to be injected once with huTNT-3/tTF fusion protein or tTF protein labeled with rhodamine B isothiocyanate (RBITC), respectively. The localization of huTNT-3/tTF fusion protein in the mouse hepatoma tissue was analyzed by confocal laser scanning microscopy 24 hour after the injection. Fifteen mice were randomly divided into three groups to be injected with the huTNT-3/tTF fusion protein, tTF protein or phosphate buffered saline (PBS) once, respectively. The tumor size was measured every two days to calculate the tumor volume. Ten days after the injection the mice were sacrificed. Samples of the tumor, heart, livers, spleen, lung, kidney and brains of the mice were taken for histopathological examination.</p><p><b>RESULTS</b>Both the huTNT-3/tTF fusion protein and tTF protein effectively promoted blood coagulation. Under the conditions of Ca(2+), the coagulation time in the 1.5, 3, 6 µmol/L huTNT-3/tTF groups was (12.90 ± 0.60) min, (10.39 ± 0.40) min and(8.15 ± 0.24) min, respectively, and the coagulation time of the 1.5, 3, 6 µmol/L tTF groups was (14.23 ± 0.46) min, (12.10 ± 0.49) min and (9.83 ± 0.52) min, respectively, the difference between the two groups was not significant (F = 0.145, P = 0.705). The huTNT-3/tTF fusion protein was similar to the tTF protein in the ability of activating FX (t = 0.101, P > 0.05). The confocal laser scanning microscopic analysis showed that RBITC-fluorescence labeled huTNT-3/tTF fusion protein was enriched in the hepatoma tissue. The tumor volume of the huTNT-3/tTF fusion protein group was significantly lower than that of the tTF and PBS groups (both P < 0.001), however, there was not significant difference between the tTF and PBS groups (t = -0.616, P > 0.05). The survival time of the huTNT-3/tTF group was (25.5 ± 2.5) d, significantly longer than that of the PBS group (17.3 ± 1.9) d and the tTF group (18.6 ± 1.9) d, (both P < 0.05).</p><p><b>CONCLUSION</b>The huTNT-3/tTF fusion protein retains the coagulation ability and has the capability of targeting to tumor vasculature, and induces thrombosis in the tumor vessels, thus to suppress the growth of hepatoma in the mice.</p>

Acquired Factor X Deficiency in Light Chain Amyloidosis: A Report of 2 Korean Cases / 대한진단검사의학회지

Amyloidosis is a heterogeneous group of diseases in which misfolding of extracellular proteins is the pathogenic factor. Light chain amyloidosis (AL) is the most common form of amyloidosis, and the causative proteins in AL are the immunoglobulin light chains produced by clonal plasma cells. Hemorrhagic events, ranging from mild subcutaneous hemorrhage to life-threatening bleeding, account for a significant proportion of morbidities and mortality in AL patients. Deficiency of factor X from deposition into amyloid fibrils has been reported to be the most common acquired factor deficiency in AL. We herein report 2 patients with acquired factor X deficiency in AL. A 55-yr-old woman with AL had a prolonged prothrombin time (PT) and an activated partial thromboplastin time (aPTT) of 2.51 International Normalized Ratio (INR) and 75.1 sec, respectively, which were corrected on mixing with normal plasma. Factor X activity was markedly decreased at 5%. The other patient was a 67-yr-old man with AL with a PT of 1.63 INR and an aPTT of 50.3 sec, which were corrected on mixing with normal plasma. Factor X activity was decreased at 17%. Neither of the patients had apparent hemorrhagic manifestations. Identification of acquired factor deficiency and timely coagulation tests are needed in the diagnostic workup and management in AL.

Acquired Factor X Deficiency in Light Chain Amyloidosis: A Report of 2 Korean Cases / 대한진단검사의학회지

Amyloidosis is a heterogeneous group of diseases in which misfolding of extracellular proteins is the pathogenic factor. Light chain amyloidosis (AL) is the most common form of amyloidosis, and the causative proteins in AL are the immunoglobulin light chains produced by clonal plasma cells. Hemorrhagic events, ranging from mild subcutaneous hemorrhage to life-threatening bleeding, account for a significant proportion of morbidities and mortality in AL patients. Deficiency of factor X from deposition into amyloid fibrils has been reported to be the most common acquired factor deficiency in AL. We herein report 2 patients with acquired factor X deficiency in AL. A 55-yr-old woman with AL had a prolonged prothrombin time (PT) and an activated partial thromboplastin time (aPTT) of 2.51 International Normalized Ratio (INR) and 75.1 sec, respectively, which were corrected on mixing with normal plasma. Factor X activity was markedly decreased at 5%. The other patient was a 67-yr-old man with AL with a PT of 1.63 INR and an aPTT of 50.3 sec, which were corrected on mixing with normal plasma. Factor X activity was decreased at 17%. Neither of the patients had apparent hemorrhagic manifestations. Identification of acquired factor deficiency and timely coagulation tests are needed in the diagnostic workup and management in AL.

Deficiência congênita de fator X: quando pensar? / Congenital factor X deficiency: when thinking?

Objetivo: Descrever o caso de um lactente portador de deficiência congênita de fator X e discutir o diagnóstico diferencial dessa coagulopatia rara. Relato do caso: Lactente, 54 dias de vida, sexo masculino, foi encaminhado paraavaliação hematológica devido a episódios prévios de hemorragia de etiologia a esclarecer. No segundo dia de vida, apresentou epistaxe e aumento do perímetro cefálico e, na segunda semana de vida, apresentou enterorragia. Foram realizados examesque evidenciaram TP e TTPA prolongados e antecedentes familiares sugestivos de diátese hemorrágica. Em nosso serviço, foram descartadascausas adquiridas que poderiam justificar o prolongamento dos tempos de coagulação (deficiência de vitamina K, infecção, hepatopatias) e também foram descartados sangramentos emoutros locais (sistema nervoso central e abdome). As dosagens dos fatores de coagulação II e V foram normais, sendo detectados níveis de fator X inferioresa 1% (FX < 1%), evidenciando deficiência grave desta proteína. Durante a investigação, o paciente apresentou novo episódio de enterorragia, sem descompensação hemodinâmica e recebeu plasma fresco congelado. Atualmente, está em seguimento ambulatorial, em uso profilático de concentrado de complexo protrombínico, sem manifestaçõeshemorrágicas. Conclusão: As coagulopatias congênitas são doenças hemorrágicas resultantes da deficiência quantitativa ou qualitativa de umaou mais das proteínas plasmáticas da coagulação. Os pacientes acometidos podem apresentar sangramentos de gravidade variável, espontâneosou pós-traumáticos, presentes ao nascimento ou diagnosticados ocasionalmente. Estas coagulopatiassão caracterizadas por herança genética, quadro clínico e laboratorial distintos entre si e, entre elas, as hemofilias e a doença de Von Willebrand são as mais comuns. São consideradas coagulopatias raras as deficiências de fatores I, II, V,...

Objective: To describe the case of an infant with congenital factor X deficiency and to discuss the differential diagnosis of other rare coagulopathies. Case report: Infant, 54-day-old male was referred for hematologic evaluation due to previous episodes of bleeding of unknown etiology. On the second day of life, he had epistaxis and increased head circumference and, in the second week of life, had rectal bleeding. Laboratory assays were performed and showed prolonged PT and APTT and family history suggestive of bleeding disorders. In our department, other acquired causes that could justify the prolongation of clotting time (vitaminK deficiency, infection, liver disease) were excluded and bleeding were also evaluated at other sites (central nervous system and abdomen). The levels of coagulation factors II and V were normal and detected levels of factor X less than 1% (FX<1%),suggesting serious deficiency of this protein. During the investigation, the patient presented a new episode of rectal bleeding, without hemodynamicinstability, and received fresh frozen plasma. He is currently in follow-up, receiving prophylactic prothrombin complex concentrate, without hemorrhagic manifestations. Conclusion: the congenital coagulopathies are bleeding disorders resulting from a quantitative or qualitative deficiency of one or more of the plasma procoagulant protein. The affected patients may have bleeding of varying sev rity, spotaneous or post traumatic, present at birthor diagnosed occasionally. These bleding disorders are characterized by specific genetic inheritance and clinical and laboratory characteristics. Amonginherited bleedingdisorders, the hemophilia and Von Willebrand disease are the most common. The deficienciesof factors I, II, V, VII, X and XIII are considered rare coagulation disorders and the differential diagnosis among these diseases is essential to guideappropriate therapy. In cases of severe deficiency of factor X, as patients may have...

Anti-Xa e antitrombínicos específicos nas síndromes isquêmicas miocárdicas instáveis com e sem supradesnível do segmento ST / Factor Xa inhibitors and selective antithrombin agents in acute coronary syndromes

As síndromes isquêmicas miocárdicas instáveis incluem um amplo espectro de manifestações da doença coronária, variando de angina instável e infarto do miocárdio sem supradesnível do segmento ST até infarto do miocárdio com dupradesnível do seguimento ST. O mecanismo fisiopatológico subjacente envolve a combinação de aterosclerose e um evento trombótico. O tratamento com heparina não fracionada ou de baixo peso molecular tem demonstrado ser eficaz e seguro nesses pacientes. Entretanto, uma limitação inerente a essas medicações é a ausência de efeito na trombina ligada ao coágulo. Novos anticoagulantes foram desenvolvidos, tendo como alvo as duas formas de trombina - livre e aquela aderida ao coágulo (inibidores diretos da trombina) - bem como outros componentes individuais da cascata de coagulação (inibidores diretos ou indiretos do fator Xa). Esses agentes anticoagulantes demonstraram resultados promissores em estudos pré-clínicos e foram avaliados em ensaios de síndromes isquêmicas agudas em grande escala. Esta revisão discute a eficácia e a segurança desses novos agentes quando comparados com os regimes que utilizam heparina como anticoagulantes de escolha.

Acute coronary syndromes include a broad spectrum of coronary artery disease ranging from unstable angina, non-ST-segment elevation myocardial infarction to ST-segment elevation myocardial infarction. The underlying pathophysiological mechanism involves a combination of atherosclerosis and a thrombotic event. Treatment with unfractionated heparin or low-molecular-weight heparin has shown to be effective and safe in these patients. However, a common limitation of these medications is the lack of effect on clot-bound thrombin. Novel anticoagulants targeted for both the free and clot-bound forms of thrombin (direct thrombin inhibitors), or other individual components of the coagulation cascade (direct or indirect factor Xa inhibitors). These anticoagulants have shown promising results in preclinical testing and have been evaluated in large-scale clinical acute coronary syndrome trials. This review discusses the efficacy and safety of these novel agents compared with heparin-based anticoagulants.

A Case Report of Palatoplasty in a Patient with Clotting Factor X Deficiency

PURPOSE: Clotting factor X deficiency is one of the least common coagulation disorders. The authors describe a case of cleft palate in a patient with a congenital clotting factor X deficiency. METHODS: In pediatric patients with a cleft palate, the coagulation problem is more worrisome, because they are more sensitive to blood than adults, and because postoperative bleeding can cause blood ingestion with subsequent vomiting, aspiration, and airway obstruction. To prevent hemorrhagic complications in the described case, fresh frozen plasma (FFP) was administered every 24 hours from the day before surgery to the second postoperative day. RESULTS: Good hemostasis, normal healing, and no complications was shown postoperatively. CONCLUSION: The replacement of fresh frozen plasma was useful in the case of congenital clotting factor deficiency for bleeding prophylaxis in cleft palate operation.

Two characteristics of a recombinant fusion protein composed of staphylokinase and hirudin: high thrombus affinity and thrombus-targeting release ofanticoagulant activity / 生物工程学报

To improve thrombolytic effect, a fusion protein SFH composed of staphylokinase (SAK) and hirudin (HV) with blood coagulation factor Xa (FXa) recognition peptide as a linker, was designed. SFH showed improved thrombolytic effect and low bleeding in vivo. Two thrombus-targeting mechanisms might account for the above features of SFH. This study was designed to study the two thrombus-targeting mechanisms of SFH. ELISA and immunohistochemistry assay were used to study the improved thrombus selectivity of SFH and the results showed that SFH, compared with SAK, displayed higher affinity for thrombin and thrombin-rich thrombus. To verify the thrombus-targeting release of anticoagulant activity of SFH, FH-a derivative of HV with only FXa recognition sequence at N terminus of HV was designed and used in animal tests. In inferior vena cava thrombosis model, FH showed equal antithrombotic effect as HV, indicating that HV could be successfully released from FH by FXa cleavage in vivo. More importantly, no prolongation of plasma TT, APTT and PT were found in FH group, but significant prolongations were discovered in HV group. This revealed that the anticoagulant activity of FH was released in thrombus-targeting way and limited in the vicinity of the thrombus, and this could be extrapolated to SFH. In conclusion, the high thrombus affinity and thrombus-targeting release of anticoagulant activity of SFH assigned low bleeding risk to SFH.

A Case of Primary Amyloidosis with Nephrotic Syndrome and Factor X Deficiency / 대한신장학회지

We report a case of nephrotic syndrome and factor X deficiency secondary to primary amyloidosis. A 58-year-old man was referred to our hospital for evaluation of nephrotic syndrome and bleeding tendency. He was confirmed to have primary amyloidosis by renal biopsy, immunofixation electrophoresis and bone marrow findings. His bleeding tendency was due to prothrombin time prolongation caused by isolated factor X deficiency. If any patient with nephrotic syndrome has bleeding tendency due to coagulation abnormalities, that patient should be considered to have factor X deficiency secondary to primary amyloidosis.

Acción de los anticuerpos antifosfolípidos sobre los mecanismos inhibitorios del factor X activado: Posible mecanismo fisiopatológico del síndrome antifosfolípido / Action by antiphospholipid antibodies on the mechanisms of inhibiting activated factor X: Possible pathophysiological mechanism of antiphospholipid syndrome

El síndrome antifosfolípido es una enfermedad autoinmunológica que se define por la presencia de anticuerpos antifosfolípidos (aFL) en el plasma de pacientes con complicaciones trombóticas tanto en territorio venoso como arterial y/o con morbilidad obstétrica. Los mecanismos patogénicos que ha sido propuestos para los aFL se pueden agrupar en dos categorías: 1) efectos inhibitorios sobre los sistemas antitrombóticos fisiológicos y 2) efectos que conducen a la activación celular. En esta revisión se presentan los datos de la acción de los aFL sobre los mecanismos inhibitorios del factor X activado, especialmente lo relacionado al sistema del inhibidor de la vía del factor tisular y del sistema proteína Z e inhibidor de proteasas dependientes de proteína Z.