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SARS-CoV-2 infection (COVID-19) has become a pandemic with a high case fatality rate that mainly affects adults. Most severely ill adult patients develop a coagulopathy that was not described until recently, and which is currently considered a main cause of death. Everything indicates that a similar phenomenon also occurs in children with COVID-19. Anticoagulant treatment has become one of the therapeutic foundations for this infection; however, its implementation in children can be difficult since, until recently, it was not considered in the pediatric population. Evidence regarding the use of anticoagulants in COVID-19 is rapidly generated, changes constantly, it is often difficult to interpret, and can be contradictory. After an extensive review of the published literature, a proposal was generated that offers suggestions for anticoagulant treatment, considering available resources in Mexico.La infección por SARS-CoV-2 (COVID-19) se ha constituido en una pandemia con alto índice de letalidad que afecta principalmente a los adultos. La mayor parte de los pacientes adultos graves desarrolla una coagulopatía que no estaba descrita, la cual actualmente se considera la principal causa de muerte. Todo indica que un fenómeno parecido ocurre también en el niño con COVID-19. El tratamiento anticoagulante se ha convertido en uno de los fundamentos terapéuticos de esta infección; sin embargo, su establecimiento en el niño puede ser difícil ya que, hasta hace poco, no estaba considerado en la población pediátrica. La evidencia respecto al uso de anticoagulantes en COVID-19 se genera con rapidez, cambia constantemente, con frecuencia es difícil de interpretar y puede ser contradictoria. Después de una extensa revisión de la literatura publicada, se generó una propuesta que ofrece sugerencias para el tratamiento anticoagulante en la que se consideran los recursos disponibles en México.

Endothelial cells (ECs) are an important component of the blood coagulation system because it maintains blood fluid. Because in patients with venous thromboembolic disease (VTD) a thrombophilic condition is not found sometimes, we investigated if endothelial colony-forming cells (ECFCs) from these patients have biological and functional abnormalities.Human mononuclear cells (MNCs) were obtained from peripheral blood from patients with VTD and controls to obtain ECFCs. These cells were assayed for their immunophenotype and electron microscopy characteristics and their ability to form capillary-like structures and to produce pro-inflammatory and pro-angiogenic cytokines and reactive oxygen species (ROS).ECFCs appeared at 7 and 21 days of culture in VTD patients and controls, respectively. ECFCs increased 8-fold in patients and emerged 1 week earlier. No differences in the size of the colonies of ECFCs were found. Numbers and time of appearance of ECFCs was different between groups. ECFC-derived ECs (ECFC-ECs) of both groups expressed CD31, CD34, CD146, and CD-309 but none expressed CD45, CD14, or CD90. Interest CD34 was highly expressed in ECFC-ECs from patients. In both groups, ECFC-ECs showed similar capacity to form capillary-like structures but ECFC-ECs from patients had significant abnormalities in the mitochondrial membrane. We found a significant increase in ROS production in ECFC-ECs from patients. There were significant differences in cytokine profiles between VTD patients and controls.We found a dysfunctional state in ECFC from VTD patients resembling some characteristics of dysfunctional ECs. These findings may help to understand some pathophysiological aspects of VTD.

Objectives: To review the current knowledge regarding the mechanisms of action and the clinical indications of Sulodexide, a glycosaminoglycan with established efcacy for the prevention of recurrent venous thromboembolism, with reduced bleeding risk. A critical review of the Methods: literature regarding Sulodexide in several data sources between 1975 and 2020. A total of 481 articles were found and analyzed but only 21 articles were considered for this review. Antithrombotic effects of Sulodexide include vas Results: cular endothelial protection, diminished platelet aggregation in response to several stimuli, inhibition of plasma coagulation factors Xa and thrombin, enhancement of brinolysis secondary to reducing PAI-1 and increasing of tPA, and decreased blood viscosity. Compared with other extended treatments, Sulodexide decreases mortality and bleeding episodes. Due to its broad range of pleiotropic effects and mainly a Conclusions: ntithrombotic, Sulodexide has emerged as a therapeutic option for the prevention of recurrent venous thromboembolism in subjects with high risk of bleeding, including elderly patients.

Endothelial colony-forming cells (ECFCs) contribute to postnatal vasculogenesis. In venous thromboembolic disease (VTD), they are functionally abnormal and produce high concentrations of TNF-α.To analyze the TNF-α signaling pathway and its relationship with the expression of cell-cycle regulators.Mononuclear cells (MNCs) were collected from the peripheral blood of 20 healthy human volunteers (controls) and 30 patients with VTD matched by age (20-50 years) and sex to obtain ECFCs. We analyzed the relative quantification of the gene transcripts of TNF, NFkB1, PLAU, HMOX1, GSS, eNOS, CDKN1A, and CDKN1B through quantitative RT-PCR (qRT-PCR assays). Identification of NF-κB and activated targets of each pathway: NF-κB (Ser536); IκBα (Ser32/Ser36); p38 (Thr180/Tyr182) JNK (Thr183/Tyr185), p53 and cell-cycle regulators: p16, p18, p21, p27, p57, Cyclin D, Cyclin E, Cyclin A, Cyclin B, CDK2, CDK4; cell-cycle status was determined by KI-67 and 7-AAD. Cells were analyzed with flow cytometry and the FlowJo vX software.In ECFCs from VTD patients, TNF-α receptor and NFkB were overexpressed and hyper-phosphorylated; eNOS and HMOX1 were down-regulated; cell-cycle regulators (p53, p18, p21) were elevated. In addition, the cell cycle was locked in the G2 phase.Our results strongly suggest that these molecular alterations in the pathway of TNF-α and cell cycle regulation induce endothelial dysfunction, reduced proliferation potential and vascular regeneration, and consequently, the occurrence of new thrombotic events.

RationaleHereditary angioedema (HAE) is a potentially life-threatening illness most commonly due to deficiency or dysfunction of C1-esterase inhibitor (C1-INH). While specific treatments are available to thwart acute exacerbations, they are extremely costly and some can be associated with rare but serious side effects. The heparins are long known to augment C1-INH activity and case reports / series have documented their efficacy in treating HAE.Objectiveto determine if unfractionated heparin and two low-molecular weight heparins (enoxaparin and nadroparin) can augment C1-INH activityex vivoin the sera of patients with HAE and in anin vitrobiochemical assay.MethodsC1-INH activity in the absence or presence of the heparin formulations were analyzed by two different methods. To measure C1-INH activityex vivo, a commercially available assay was utilized with patient sera, excess amounts of C1s, and a substrate of C1s which, upon cleavage by C1s, produces a chromogenic product. To determine biochemically the C1-INH activityin vitro, a pharmacologic grade C1-INH, recombinant C1s (C1s-CCP12SP), and a peptide substrate of C1s were employed. Microscale thermophoresis was used to determine whether C1-INH binds to heparin.Main resultsin patient sera, nadroparin was superior to enoxaparin and unfractionated heparin in augmenting C1-INH activity, followed by enoxaparin and then unfractionated heparin. In thein vitrobiochemical assay, all three heparins augmented C1-INH-C1s binding linearly in a dose-dependent fashion. Microscale thermophoresis assay demonstrated that nadroparin binds to C1-INH, providing a mechanism by which heparin facilitates the interaction between C1-INH and the proteases known to produce bradykinin, the mediator of HAE.Conclusionlow-molecular weight heparin augments C1-INH activity and should be studied as a potential treatment for acute HAE.

Introduction Postpartum haemorrhage (PPH) is the main cause of maternal morbidity and mortality globally, but it is far more important in non-developed countries. PPH represents 25% of all maternal deaths worldwide. Women with von Willebrand disease (VWD) and other inherited haemorrhagic disorders are at increased risk of PPH. Our aim was to establish a probable association of severe PPH in women with a history of haemostatic abnormalities. Methods An observational, controlled study of adult women with a one or more episodes of severe PPH requiring treatment in an intensive care unit or >10 units of blood products during the 24-hour period after diagnosis and their controls. The tests performed were blood cell count, blood group, renal, viral, liver function and haemostatic tests, fibrinogen, activity of the plasma factors and specific test to diagnose and classify VWD. Results We included 124 women with 133 PPH events and their controls. The median age at the first event was 25.5 years old. Results were significantly different between the groups in terms of fibrinogen concentration, VWF:Ag, VWF:RCo and FVIII. A specific diagnosis was established in 69 (55.6) and 4 (3.2%) patients in the PPH group and controls, respectively. Of 61 patients with VWD, 57 had type 1, two had type 2A, and another two had type 2B. Conclusion Our results show a relationship between PPH and inherited haemostatic disorders. VWD was the most frequent diagnosis. Appropriate and opportune diagnosis before pregnancy of inherited haemostatic disorders may be important to effectively prevent and treat PPH.

Background. The treatment of rheumatoid arthritis (RA) has significantly improved since the introduction of biologics like rituximab. Rituximab achieves selective B lymphocyte depletion and, thereby, reduce inflammation. It has adverse reactions related to the immunogenic response. Objective. The aim of this study was to evaluate the frequency and severity of rituximab adverse reactions in Mexican patients with RA. Methods. A prospective, observational, descriptive, open-labeled, multicenter cohort study of intensive pharmacovigilance was conducted during 17 months in 10 hospitals. We included 335 adult patients with RA, 26 male an 309 female. They received two doses of rituximab (1000 mg) on days 1 and 15 in combination with methotrexate. Adverse reactions were graded according to the National Cancer Institute (NCI) scale and causality was established with the Naranjo algorithm. Infusions were classified as fast (0 to 180 minutes) and slow (> 181 minutes). The first and second infusions were compared. Results. The total number of infusion episodes recorded was 631 and 36 adverse reactions were informed in 24 patients (7.1 %). There were no differences between the variances of the first and second infusions. All the adverse reactions were considered mild to moderate (NCI Scale). According to Naranjo algorithm, the adverse reactions to rituximab were possible or probable. The infusion speed did not have an influence on the adverse reactions; whereas the incident rate was lower than that reported by other authors. Conclusions. Rituximab has a favorable safety profile in Mexican patients.

Multiple myeloma (MM) is a disease characterized by antitumoral immune dysfunction. The objective of the present study was to determine lymphocyte subsets (B, T, NK, NKT, iNKT, dendritic cells, and regulatory T cells) in 68 newly diagnosed patients and 113 healthy donors. Lymphocyte subsets were studied in the same patients 6 months after treatment. Pre-treatment values of CD4+ T cells, NK cells, type 2 dendritic cells, and B cells in MM patients were lower than in healthy donors. Forty patients (59%) received MPT treatment and 28 (41%) thal-dex. Patients with no response to treatment, exhibited a decrease in CD4+ T cells and NK cells, as well as an increase in Treg cell numbers. Median DFS and OS was lower in patients not achieving response, in patients having low numbers of NK cells, and higher values of LDH. The number of CD4 T cells, NK, DC2, and B cells at diagnosis is lower in patients with MM. Non-responder patients had lower CD4 and NK, but higher Treg cell values. Patients in which response is not achieved, and those holding lower values of NK cells and higher levels of LDH, have poor DFS and OS.

SARS-CoV-2 contains certain molecules that are related to the presence of immunothrombosis. Here, we review the pathogen and damage-associated molecular patterns. We also study the imbalance of different molecules participating in immunothrombosis, such as tissue factor, factors of the contact system, histones, and the role of cells, such as endothelial cells, platelets, and neutrophil extracellular traps. Regarding the pathogenetic mechanism, we discuss clinical trials, case-control studies, comparative and translational studies, and observational studies of regulatory or inhibitory molecules, more specifically, extracellular DNA and RNA, histones, sensors for RNA and DNA, as well as heparin and heparinoids. Overall, it appears that a network of cells and molecules identified in this axis is simultaneously but differentially affecting patients at different stages of COVID-19, and this is characterized by endothelial damage, microthrombosis, and inflammation.

End-stage renal disease (ESRD) patients have an elevated risk of cardiovascular (CV) complications including acute myocardial infarction (AMI); endothelial dysfunction and accumulation of uremic toxins have been associated with such CV-events. To explore which molecular pathways are involved in this CV-complication and the effects of the uremic serum on gene expression, an endothelial dysfunction model was studied through microarrays and pathway analysis. mRNA was isolated of human coronary arterial endothelial cells (HCAEC) primary cultures supplemented with 20% uremic serum from two groups of patients, USI: ESRD-patients; UCI: ESRD-AMI-patients. Affymetrix GeneChip® microarray and the LIMMA-package (Linear Models for Microarray Data) of the Bioconductor sofware17 was implemented to identify relevant DEGs between the two groups of uremic patients. Protein-protein interaction networks and pathway analysis were made to analyze the interaction and expression tendency of differentially expressed genes. 100 differentially expressed genes were identified from two data sets triggered by uremic state using bioinformatics, from 16,607. After in a new cohort, 30 genes were overexpressed in UCI group, which we identified 500 ontological genetic terms and one KEGG-pathway with p < 0.05. The metabolic pathway significantly represented was the MAPK signaling pathway. Network analysis showed six genes (PTGS2, SELE, ICAM1, HMOX1, EGR1, and TLR2) that represent potential markers for ESRD with AMI, as an approximation to their underlying mechanisms. The results obtained suggest that uremic toxins in patients with ESRD can alter HCAEC and modify the gene expression profile, which could have an impact on the development of cardiovascular complications in these patients.

Vitamin K antagonists (VKA) are a therapeutic alternative in patients with venous thromboembolic disease; however, numerous factors affect their pharmacology.To evaluate the quality of VKA anticoagulation at three different time periods in Mexico.Prospective study, nested in patient cohorts at three different clinical scenarios between 2013 and 2019. Outpatients with indication for treatment with VKAs for at least 12 months were included. Patients were managed according to the criteria of the treating physician.Patient general characteristics were similar between groups, except for the VKA indication. The results of 4,148 patients and 38,548 INR assessments were analyzed. The times in therapeutic range during the three phases of the study and pooled data were significantly higher for the anticoagulation clinic. Only the number of patient visits was significantly associated with the results, unlike age, gender, and type of VKA.VKAs are widely used, but it is difficult for therapeutic goals to be achieved, especially in non-specialized clinical services. Creation of anticoagulation clinics is an urgent need for the Mexican health system.Los antagonista de la vitamina K (AVK) son una alternativa terapéutica en los pacientes con enfermedad tromboembólica venosa; sin embargo, numerosos factores afectan su farmacología.Evaluar la calidad de la anticoagulación AVK durante tres diferentes periodos en México.Estudio prospectivo, anidado en cohortes de pacientes en tres escenarios clínicos entre los años 2013-2019. Se incluyeron pacientes no hospitalizados con indicación para recibir AVK por al menos 12 meses, quienes fueron manejados de acuerdo con el criterio del médico tratante.Las características generales de los pacientes fueron similares entre los grupos, excepto por la indicación para usar los AVK. Se analizaron los resultados de 4148 pacientes y 38 548 evaluaciones de INR. Los tiempos en rango terapéutico durante las tres fases del estudio y los datos acumulados fueron significativamente mayores en la clínica de anticoagulación. Solo el número de visitas de control de los pacientes se asoció significativamente con los resultados, a diferencia de la edad, el sexo y el tipo de AVK.Los AVK se utilizan ampliamente, pero es difícil alcanzar la meta terapéutica, sobre todo en servicios clínicos no especializados. La creación de clínicas de anticoagulación es una necesidad urgente en el sistema mexicano de salud.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is the cause of the coronavirus disease 2019 (COVID-19) pandemic, which has a high case fatality rate. Most severely ill patients develop a special type of coagulopathy that had not been described before and that is now considered the main cause of death. For this reason, anticoagulant treatment has become one of the cornerstones of the treatment of this infection. However, the rate at which the evidence regarding the use of anticoagulants is generated is quite fast, and sometimes it is difficult to interpret and conflicting. After having performed an extensive review of the published literature, this proposal for the use of anticoagulant treatment is made, taking into account available resources in Mexico.La infección por coronavirus 2 del síndrome respiratorio agudo grave (SARS-CoV-2) es la causante de la pandemia de enfermedad por coronavirus 2019 (COVID-19), con un índice de letalidad alto. La mayoría de los pacientes graves desarrollan un tipo especial de coagulopatía no descrito hasta ahora y la cual se considera ahora la principal causa de muerte. Por esta razón, el tratamiento anticoagulante se ha convertido en una de las piedras angulares del tratamiento de esta infección. Sin embargo, la velocidad con la que se genera la evidencia respecto al uso de anticoagulantes es muy rápida y, en ocasiones difícil de interpretar y contradictoria. Luego de hacer una revisión extensa de la literatura publicada, se hace esta propuesta para el uso del tratamiento anticoagulante tomando en cuenta los recursos disponibles en México.

Previous studies demonstrated that the majority of Hodgkin lymphoma (HL) patients achieve response after treatment, while 5% become refractory. Studies analyzing the role of lymphocyte subsets in peripheral blood are limited. This investigation sought to evaluate peripheral blood lymphocyte subsets and soluble MHC class I chain-related proteins A and B (sMIC-A/B) and their correlation with survival in patients with newly diagnosed HL. The study recruited 36 patients and 72 healthy donors. HL patients showed a decrease in CD4, B, monocytes, NK, and NKT cells; and an increase in γ-δ T cells and soluble MIC-A serum levels. Higher values of s-MIC

Hereditary hemophilias are X-linked inherited bleeding disorders defined as deficiencies of the coagulation factors VIII or IX. They are characterized by easy to provoke or spontaneous bleeding. HIV infection in hemophilic patients is a risk factor for the reduction of CD4+ T cells. There is no information regarding the cellular immune function in HIV-negative patients with hemophilia. To evaluate the number of lymphocyte subsets in adult patients with hemophilia A or B as compared with healthy donors. 39 Adult hemophilics and 27 healthy donors were included. Lymphocyte subsets [CD4 and CD8 T cells, natural killer cells, natural killer T (NKT) cells, invariant NKT (iNKT) cells, gamma-delta T (γδT) cells, type 1 and 2 dendritic cells, CD14 monocytes, CD4 and CD8 regulatory T cells (Tregs), and B cells], were analyzed by flow cytometry. A significant decrease of CD4+ T lymphocytes, γδT cells, iNKT cells, CD4+ and CD8+ Tregs was observed in patients with hemophilia. Those patients having factor VIII inhibitor had the lowest CD4+ Treg and CD8+ Treg counts. CD14 monocytes were increased, as well as iNKT and type 2 dendritic cells in obese-overweight hemophilics. CD4+ lymphocytes, iNKT, γδT cells, and Tregs (CD4+ and CD8+), are significantly decreased in patients with hemophilia. Depletion of Tregs is more important in patients with factor VIII inhibitor. Physicians caring for hemophilia patients should realize that, even when they are not suffering infections frequently, may have early evidence of cellular immunodeficiency.

SARS-CoV-2 infection (COVID-19) has become a pandemic with a high case fatality rate that mainly affects adults. Most severely ill adult patients develop a coagulopathy that was not described until recently, and which is currently considered a main cause of death. Everything indicates that a similar phenomenon also occurs in children with COVID-19. Anticoagulant treatment has become one of the therapeutic foundations for this infection; however, its implementation in children can be difficult since, until recently, it was not considered in the pediatric population. Evidence regarding the use of anticoagulants in COVID-19 is rapidly generated, changes constantly, it is often difficult to interpret, and can be contradictory. After an extensive review of the published literature, a proposal was generated that offers suggestions for anticoagulant treatment, considering available resources in Mexico.

Context The majority of Hodgkin lymphoma (HL) patients achieve response after treatment, but 5%–10% of them become refractory. It is very important in this fraction of patients to understand the mechanisms used by malignant cells to avoid the anti-tumoral immune response and, consequently, the development of resistance to any treatment modality. Studies trying to analyze the number and function of lymphocyte subsets in peripheral blood are limited. Objective Evaluate the number of peripheral blood lymphocyte subsets, and soluble (s)MIC-A/B, in patients with newly diagnosed HL. Design Peripheral blood (SP) in EDTA from patients diagnosed with HL was taken prior to the start of treatment. Healthy donors (SD) were included as controls. Setting By flow cytometry, using monoclonal antibodies, lymphocyte subpopulations were determined, and, by ELISA, the levels of sMICA and sMICB were determined. Statistical analysis was performed using SPSS software. Patients or Other Participants Thirty-six patients with de novo HL (N=36) and 72 donors were included. Patients were of both genders, over 18 years old, with informed consent, never treated with chemotherapy, and without contaminating viral disease. Interventions There were no interventions, only samples taken as described above. Results CD4 T lymphocytes, B-cells, monocytes, NK, and NKT cells were decreased in patients; γ-δ T cells and soluble MIC-A serum levels were increased. Overall survival (OS) was better in patients with sMIC-A values Conclusions Peripheral blood CD4 T lymphocytes, B cells, monocytes, NK, and NKT cells were decreased in patients with HL; s-MIC-A and γ-δ T cells were increased. s-MIC-A and peripheral blood NKT cells had clinical relevance for OS. These findings may contribute to explain, at least in part, the many different mechanisms of tumor escape from immune surveillance in this disease.

There are classical risk factors associated with arterial thrombosis (AT) or venous thromboembolic disease (VTD). However, less is known about these risk factors and AT or VTD episodes in patients with antiphospholipid syndrome (APS). Our aim was to elucidate whether APS-related thrombotic episodes are associated with the same risk factors as the non-APS population. We gathered demographics, medical history, complications, and causes of death associated with the risk factors for AT or VTD in patients with APS. We analyzed 677 thrombotic events in 386 patients. Type 2 diabetes mellitus and grade 3 obesity were associated with VTD instead of AT. There were no significant differences between the groups for almost all laboratory tests analyzed, although lupus anticoagulant was significantly higher in the VTD group. We suggest that thrombosis in APS is due to the APS itself and that the risks factors for AT or VTD do not have a main role. Our findings may have an ethnical background. Therefore, it may be difficult to elaborate predictive thrombotic clinical scores applicable to patients with different ethnical background.

Acquired hemophilia (AH) is an autoimmune hemostatic disorder mediated by autoantibodies directed against factor VIII: C. In 52% of cases, the cause is unknown or is not associated with other pathological entities; in the rest, there are concomitant factors: lupus, rheumatoid arthritis, cancer, pregnancy, and medications. In Mexico, there is not a registry of AH, and awareness of the disease among health personnel is low. The groups with the highest incidence are women of childbearing age and individuals older than 70 years. It is characterized by severe bleeding, especially after trauma and normal childbirth or cesarean delivery, and large ecchymoses in the trunk and extremities. The suspicion is simple, it just takes for sudden, severe hemorrhage and a prolonged activated partial thromboplastin time that is not corrected with plasma to concur in an individual. Treatment involves achieving hemostasis and eradicating the antibody. The former is achieved with recombinant activated factor VII or activated prothrombin complex concentrate. Cyclophosphamide, prednisone or rituximab are used to eradicate the antibody. Most cases of AH are not diagnosed, which translates into a high mortality rate. Given that awareness about the disease among physicians is low, it is not suspected, neither diagnosed, and nor is it treated. This document reviews the most recent data on AH and expands on its diagnosis and treatment.La hemofilia adquirida (HA) es un trastorno hemostático autoinmune ocasionado por autoanticuerpos dirigidos contra el factor VIII: C. En 52 % de los casos, la causa se desconoce o no se asocia con otra entidad patológica; en el resto, existen factores concomitantes: lupus, artritis reumatoide, cáncer, embarazo y medicamentos. En México no existe registro ni conciencia de la enfermedad entre el personal de salud. Los grupos de mayor incidencia son las mujeres en edad reproductiva y los individuos mayores de 70 años. Se caracteriza por hemorragia grave, sobre todo posterior a traumatismos y parto o cesárea, y equimosis grandes en tronco y extremidades. La sospecha es simple, basta que concurran hemorragia súbita, grave y un TTPa prolongado que no se corrige con plasma. El tratamiento consiste en lograr la hemostasia y erradicar el anticuerpo; lo primero se logra con el factor VII activado recombinante o concentrado del complejo de protrombínico activado. La ciclofosfamida, prednisona o rituximab sirven para erradicar el anticuerpo. La mayoría de los casos no son diagnosticados y la mortalidad es alta. Ya que los médicos desconocen el problema, no se sospecha, no se diagnostica y no se trata. Este documento revisa los datos más recientes de la HA y abunda en el diagnóstico y tratamiento.

Rivaroxaban is a direct oral anti-factor Xa anticoagulant. It has recently been suggested that rivaroxaban may affect platelet function in vitro; however, little is known about the clinical impact of this likely antiplatelet effect and whether this probable phenomenon is dose-dependent. Our aim was to determine whether rivaroxaban at 4 different doses inhibits direct platelet aggregation. We included adult patients of both sexes and who were allocated to one of the following groups depending on the prescribed daily dose of rivaroxaban: 5, 10, 15, and 20 mg. In 80 patients (20 patients/group), the percentage of platelet aggregation was determined by means of platelet aggregometry tests before and after rivaroxaban use. Basal samples were obtained before starting rivaroxaban and 1 month after treatment, both 2 and 24 hours after the last dose of the drug (12 hours after in the case of rivaroxaban 5 mg). We used 5 platelet agonists: adenosine diphosphate, epinephrine, arachidonic acid, collagen, and thrombin. There were no significant changes in the percentage of platelet aggregation before and after rivaroxaban use independently of the dose administered and the agonist used. Our results have clearly shown that rivaroxaban, even at a high dose, does not directly affect platelet aggregation.

Atherothrombosis is the cornerstone of cardiovascular diseases and the primary cause of death worldwide. Genetic contribution to disturbances in lipid metabolism, coagulation, inflammation and oxidative stress increase the susceptibility to its development and progression. Given its multifactorial nature, the multiloci studies have been proposed as potential predictors of susceptibility. A cross-sectional study was conducted to explore the contribution of nine genes involved in oxidative stress, inflammatory and thrombotic processes in 204 subjects with atherothrombosis matched by age and gender with a healthy group (n= 204). To evaluate the possibility of spurious associations owing to the Mexican population genetic heterogeneity as well as its ancestral origins, 300 unrelated mestizo individuals and 329 Native Americans were also included.ALOX5,LPA,MMP9andTPOgene polymorphisms, as well as their multiallelic combinations, were twice to four times more frequent in those individuals with clinical manifestations of atherothrombosis than in the healthy group. Once adjusting for population stratification was done, these differences remained. Our results add further evidence on the contribution ofALOX5,LPA,MMP9andTPOpolymorphisms to atherothrombosis development in the middle-aged group, emphasizing the multiethnic studies in search of gene risk polymorphisms.

Background: Numerous polymorphisms in candidate genes coding for haemostatic system proteins have been proposed as risk factors for thrombosis. Methods: We performed a case-control study of consecutive ischaemic stroke survivors aged ≤45 years, treated at our neurology department from 2006 to 2014. Polymerase chain reaction–restriction fragment length polymorphism identified the following polymorphisms: Thr325Ile and Ala147Thr in TAFI, 4 G/5 G in PAI-1, PLA1/A2 in platelet glycoprotein IIb/IIIa, Glu298Asp in eNOS, and C677 T in 5,10-MTHFR. A multivariate logistic regression analysis was performed to evaluate the independent risk of stroke. Results: 204 cases and 204 age- and sex-matched controls were included in the study. Clinical and genetic variables associated with ischaemic stroke were hypertension (P = .03), tobacco use (P = .02), and the polymorphisms Glu298Asp (genotype: P = .001, allele frequency: P = .001) and C677 T (genotype: P = .01); the Ala147Thr, Thr325IIe, 4 G/5 G, and PLA1/A2 mutations were not associated with ischaemic stroke. The 298Asp (P = .03) and T (P = .01) alleles, hypertension (P = .03), tobacco use (P = .01) and family history of stroke (P = .04) were identified as independent risk factors. Conclusion: The polymorphisms Glu298Asp and C677T, affecting the eNOS and 5,10-MTHFR enzymes, respectively, and smoking, hypertension, and family history of stroke were associated with ischaemic stroke in young Mexican patients; this was not the case for the Thr325Ile, Ala147Thr, 4 G/5 G, and PLA1/A2 polymorphisms of the genes coding for fibrinolytic proteins and platelet receptors. Resumen: Introducción: Diversos polimorfismos en genes candidatos que codifican proteínas del sistema hemostático se han propuesto como factores de riesgo para el desarrollo de trombosis. Métodos: Casos y controles, sobrevivientes de enfermedad vascular cerebral (EVC) isquémico idiopático ≤ 45 años de edad del servicio de Neurología incluidos de manera consecutiva del 2006 al 2014. Por PCR-RFLP se identificaron los polimorfismos: Thr325Ile y Ala147Thr del gen de TAFI, 4 G/5 G del gen de PAI-1, PLA1/A2 del gen de la glicoproteína plaquetaria IIb/IIIa, Glu298Asp del gen de eNOS, y C677 T del gen de la 5,10 MTHFR. Se realizó un análisis multivariado de regresión logística para calcular el riesgo independiente de EVC. Resultados: 204 casos y 204 controles pareados por edad y sexo. Se asoció al polimorfismo Glu298Asp (genotipo p=0.001 y frecuencia alélica p=0.001), C677 T (genotipo p=0.01), hipertensión (p=0.03) y tabaquismo (p=0.02) con la presencia de EVC isquémico, no así para los polimorfismos Ala147Thr, Thr325IIe, 4 G/5 G, y PLA1/A2. Se identificó como factor de riesgo independiente al alelo 298Asp (p = 0.03), T (p = 0.01), hipertensión (p = 0.03), tabaquismo (p = 0.01) y AHFEAT (p = 0.04). Conclusiones: Los polimorfismos Glu298Asp y C677 T de los genes que codifican a la enzima eNOS y 5,10 MTHFR, tabaquismo, hipertensión y AHFEAT, se asociaron a la presencia de EVC isquémico en jóvenes mexicanos, no así el Thr325Ile, Ala147Thr, 4 G/5 G, PLA1/A2 en genes que codifican proteínas del sistema de fibrinólisis y receptores plaquetarios.

Background. Metabolic and genetic factors induce plasminogen activator inhibitor type-1 (PAI-1) overexpression; higher PAI-1 levels decrease fibrinolysis and promote atherothrombosis.Aim. To assess PAI-1 antigen levels among subjects with type 2 diabetes mellitus (T2DM) plus Metabolic Syndrome (MetS) before clinical manifestations of atherothrombosis and the contribution of metabolic factors and 4G/5G polymorphism of PAI-1 gene on the variability of PAI-1.Methods. We conducted an observational, cross-sectional assay in a hospital in Mexico City from May 2010 to September 2011. MetS was defined by the International Diabetes Federation criteria. PAI-1 levels and 4G/5G polymorphism were determined by ELISA and PCR-RFLP analysis.Results. We enrolled 215 subjects with T2DM plus MetS and 307 controls. Subjects with T2DM plus MetS had higher PAI-1 levels than the reference group (58.4 ± 21 versus 49.9 ± 16 ng/mL,p=0.026). A model with components of MetS explained only 12% of variability on PAI-1 levels (R2= 0.12;p=0.001), withβ=0.18(p=0.03) for hypertension,β=-0.16(p=0.05) for NL HDL-c, andβ=0.15(p=0.05) for NL triglycerides.Conclusion. Subjects with T2DM plus MetS have elevated PAI-1 levels before clinical manifestations of atherothrombotic disease. Metabolic factors have a more important contribution than 4G/5G polymorphism on PAI-1 plasma variability.

Background: STRs are powerful tools intensively used in forensic and kinship studies. Aim: In order to assess the effectiveness of non-CODIS genetic markers in forensic and paternity tests, the genetic composition of six mini short tandem repeats—mini-STRs—(D1S1656, D2S441, D6S1043, D10S1248, D12S391, D22S1045) and the microsatellite SE33 in Mestizo and Amerindian populations from Mexico were studied. Subjects and methods: Using multiplex polymerase chain reactions and capillary electrophoresis, this study genotyped all loci from 870 chromosomes and evaluated the statistical genetic parameters. Results: All mini-STRs studied were in agreement with HW and linkage equilibrium; however, an important HW departure for SE33 was found in the Mestizo population (p ≤ 0.0001). Regarding paternity and forensic statistical parameters, high values of combined power discrimination and mean power of exclusion were found using these seven markers. The principal co-ordinate analysis based on allele frequencies of three mini-STRs showed the complex genetic architecture of the Mestizo population. Conclusion: The results indicate that this set of loci is suitable to genetically identify individuals in the Mexican population, supporting its effectiveness in human identification casework. In addition, these findings add new statistical values and emphasise the importance of the use of non-CODIS markers in complex populations in order to avoid erroneous assumptions.

Background: Postpartum haemorrhage (PPH), is the main cause of maternal morbidity and mortality globally but it is far more important in non-developed countries. PPH represents 25% of all maternal deaths worldwide. von Willebrand disease (VWD) is a disease caused by quantitative or qualitative deficiency of the von Willebrand factor (VWF) and women with VWD are at increased risk of PPH. Our aim was to establish a probable association of severe PPH in women with a history of haemostatic abnormalities. Methods: An observational, controlled study of adult women with a history of one or more episodes of life-threatening severe PPH requiring treatment in an intensive care unit or >10 units of blood products during the 24-hour period after diagnosis and their controls. The following tests were performed: blood cell count, blood group, renal, viral, liver function and haemostatic tests, fibrinogen, activity of the plasma factors and specific test to diagnose and classify VWD. Findings: We included 124 women with PPH and their controls. A total of 133 PPH events were recorded. The median age at the first event was 25.5 years old. Results were significantly different between the groups in terms of fibrinogen concentration, VWF:Ag, VWF:RCo, and FVIII. A specific diagnosis was established in 69 (55.6) and 4 (3.2%) patients in the PPH group and controls, respectively. Of 61 patients with VWD, 57 had type 1, two had type 2A, and another two had type 2B. Other non-significant haemostatic deficiencies were found between the groups. Interpretation: Our results show a relationship between PPH and inherited haemostatic disorders. VWD was the most frequent diagnosis but it was unknown at the time of delivery in all patients. Appropriate and opportune diagnosis before pregnancy of inherited haemostatic disorders, particularly VWD, may be important to effectively prevent and treat PPH. Funding: None. Declaration of Interest: Karim Majluf-Cruz: no conflict of interest to declare. Liliana Anguiano-Robledo: no conflict of interest to declare. Claudia C. Calzada-Mendoza: no conflict of interest to declare. Jesus Hernandez-Juarez: no conflict of interest to declare. Manuel Moreno-Hernandez: no conflict of interest to declare. Victor Manuel Dominguez-Reyes: no conflict of interest to declare. Anahi Guadalupe Figueroa-Torres: no conflict of interest to declare. Patricia Gomez-Rosas: no conflict of interest to declare. Rodrigo Arreola-Diaz: no conflict of interest to declare. Maria Teresa Garcia-Lee: no conflict of interest to declare. Maria Tania Ricardo-Moreno: no conflict of interest to declare. Rosa Elena Sosa-Camas: no conflict of interest to declare. Jaime Garcia-Chavez: no conflict of interest to declare. Irma Isordia-Salas: no conflict of interest to declare. Abraham Majluf-Cruz: no conflict of interest to declare. Ethical Approval: The study protocol was approved by the Human Ethics Committees and the Medical Research Councils of our institutions. Informed written consent was obtained from all patients before enrollment in the study. All women received complete information about the aim of the study and explained that their participation was voluntary. Data obtained was made anonymous immediately after blood drawing.

Background and Purpose. The thrombin-activatable fibrinolysis inhibitor (TAFI) is an important inhibitor of fibrinolysis and plays a critical role in the pathogenesis of arterial thrombosis; genetic polymorphisms of the TAFI gene affect its activity and increase the risk of thrombosis. Moreover, studies in young patients are still scarce. The aim was to examine the contribution of the Thr325Ile and Ala147Thr polymorphisms with ST acute myocardial infarction (STEMI) or idiopathic ischemic stroke (IIS) in the young Mexican population. Methods. A total of 244 patients with STEMI ≤45 years of age and 244 controls. In a second study, 250 patients with IIS ≤45 years of age were recruited, including 250 controls. In both studies, cases and controls were matched by age and sex. The polymorphisms were determined in all participants by PCR-RFLP. Results. There was significant difference in the Thr325Ile genotype distribution (P=0.001) and allele frequency (P=0.001) between STEMI and control groups, but no difference in the Ala147Thr genotype distribution (P=0.24) and allele frequency (P=0.46), neither in the Thr325Ile genotype distribution (P=0.25) nor in the Ala147Thr genotype distribution (P=0.46) or their allele frequencies; there was significant difference between IIS and the control group. There were independent factors for STEMI: the Ile allele (P=0.01), type 2 diabetes mellitus (P=0.001), hypertension (P=0.001), smoking (P=0.001), dyslipidemia (P=0.001), and family history of atherothrombotic disease (P=0.001). The independent factors for IIS were hypertension (P=0.001), smoking (P<0.01), and family history of atherothrombotic disease (P<0.01). Conclusions. The Thr325Ile polymorphism, but no Ala147Thr polymorphism, represents an independent risk factor for STEMI in the young Mexican population.

espanolObjetivo: Examinar la contribucion de los polimorfismos G20210A, G1691A y G10976A en los factores de coagulacion FII, FV y FVII respectivamente; Glu298Asp y C677T en la oxido nitrico sintasa endotelial y 5,10 metilentetrahidrofolato reductasa, en poblacion joven mexicana con infarto cerebral (IC). Metodo: Se incluyeron 224 pacientes ≤ 45 anos de edad con diag- nostico de IC y 224 controles pareados por edad y sexo, de 2006 a 2014. Los polimorfismos fueron determinados por la tecnica de reaccion en cadena de la polimerasa-polimorfismos de longitud de fragmentos de restriccion. Resultados: Identi- ficamos una diferencia significativa en la distribucion genotipica de los polimorfismos Glu298Asp (p = 0.001) y C677T (p = 0.01) entre el grupo de pacientes con IC y el control. La distribucion genotipica de los polimorfismos FII G20210A, FV G1691A y FVII G10976A fue similar entre ambos grupos. Se identificaron como factores independientes de IC los polimorfismos Glu298Asp y C677T, el tabaquismo, la hipertension y el antecedente de familiar de enfermedad trombotica. Conclusiones: Los po- limorfismos Glu298Asp y C677T, pero no FII G20210A, FV G1691A y FVII G10976A, se asociaron con IC. Nuestros resulta- dos sugieren que la disfuncion endotelial en interaccion sinergica con otros factores de riesgo, como tabaquismo e hipertension, contribuye al IC en individuos jovenes. EnglishObjective: To examine the contribution the polymorphisms G20210A, G1691A and G10976A in the coagulation factors FII, FV, FVII, respectively; Glu298Asp and C677T in eNOS and 5,10 MTHFR in young Mexican population with cerebral infarction (CI). Methods: 224 patients ≤ 45 years of age with CI and 224 controls matched by age and gender were recruited from 2006 and 2014. The polymorphisms were determined by polymerase chain reaction-restriction fragment length polymorphism. Results: We identified a significant difference in the genotype distribution of Glu298Asp (p = 0.001) and C677T (p = 0.01) polymorphisms between CI patients and control groups. The genotype distribution in the FII G20210A, FV G1691A and FVII G10976A poly- morphisms were similar. There were independent factors for ischemic stroke: Glu298Asp and C677T polymorphisms, smoking; hypertension, and familial history of thrombotic disease. Conclusions: The Glu298Asp and C677T, but not FII G20210A, FV G1691A and FVII G10976A polymorphisms were associated with CI. Our results suggest that endothelial dysfunction and the synergist interaction with other factors such as smoking and hypertension contribute to CI in young individuals.

Objective The renin-angiotensin system (RAS) is a hormonal signaling mechanism implicated in the atherosclerosis and regulation of blood pressure. Angiotensin-converting enzyme (ACE) a key enzyme in the RAS, plays important roles in vascular remodeling atherosclerosis, and ischemic stroke. The aim of this study was to examine the possible contribution of the I/D in the ACE gene, M235T and T174M in the angiotensinogen (AGT) gene polymorphisms with ischemic stroke in young Mexican population. Materials and methods A total of 224 patients with diagnosis of idiopathic ischemic stroke ≤45 years of age, and 224 controls matched by age and gender, were recruited from 2006 and 2016. The I/D, M235T and T174M polymorphisms were determined in all participants by PCR-RFLP. Results There was a significant difference in the M235T genotype distribution (p = 0.01) and allele frequency between two groups (p = 0.01). Also, we found a significant difference in the T174M genotype distribution (p = 0.01) and the allele frequency between groups; (p = 0.02). In contrast, in I/D polymorphism, there was a similar genotype distribution; (p = 0.20) and allele distribution (p = 0.20). There were independent factors for ischemic stroke: M235T and T174M polymorphisms, smoking, hypertension, and familial history of atherothrombotic disease. The AGT levels were increased in the group of patients with stroke compared with the control group, but the AGT levels were not influenced by the allele or genotype in each polymorphism. Conclusions The M235T and T174M polymorphisms represented an increased risk for stroke in young Mexican individuals. In contrast, the I/D was not associated with in the same group of patients. The AGT levels were higher in the acute phase of stroke, but it was not determined by the polymorphisms.

Introduction Endothelial cells (ECs) are an important component of the blood coagulation system because it maintains blood fluid. Because in patients with venous thromboembolic disease (VTD) a thrombophilic condition is not found sometimes, we investigated if endothelial colony-forming cells (ECFCs) from these patients have biological and functional abnormalities. Patients and methods Human mononuclear cells (MNCs) were obtained from peripheral blood from patients with VTD and controls to obtain ECFCs. These cells were assayed for their immunophenotype and electron microscopy characteristics and their ability to form capillary-like structures and to produce pro-inflammatory and pro-angiogenic cytokines and reactive oxygen species (ROS). Results ECFCs appeared at 7 and 21 days of culture in VTD patients and controls, respectively. ECFCs increased 8-fold in patients and emerged 1 week earlier. No differences in the size of the colonies of ECFCs were found. Numbers and time of appearance of ECFCs was different between groups. ECFC-derived ECs (ECFC-ECs) of both groups expressed CD31, CD34, CD146, and CD-309 but none expressed CD45, CD14, or CD90. Interest CD34 was highly expressed in ECFC-ECs from patients. In both groups, ECFC-ECs showed similar capacity to form capillary-like structures but ECFC-ECs from patients had significant abnormalities in the mitochondrial membrane. We found a significant increase in ROS production in ECFC-ECs from patients. There were significant differences in cytokine profiles between VTD patients and controls. Conclusions We found a dysfunctional state in ECFC from VTD patients resembling some characteristics of dysfunctional ECs. These findings may help to understand some pathophysiological aspects of VTD.