A focus on the roles of histones in health and diseases.

Over time, the knowledge on the role of histones has significantly changed. Initially, histones were only known as DNA packaging proteins but later, it was discovered that they act extracellularly as powerful antimicrobial agents and also as potentially self-detrimental agents. Indeed, histones were found to be the most abundant proteins within neutrophil extracellular traps what ultimately highlighted their microbicidal function. In addition, extracellular histones proved to be involved in triggering exacerbated inflammatory and coagulation responses, depending on the cell type affected. Consequently, several investigations were conducted towards studying the potential of histones and their derivatives as either biomarkers or therapeutic target candidates in different diseases in which inflammation and thrombosis have a key pathophysiological role, such as sepsis, thrombosis and different types of cancer. The main objective of this review is to summarize and discuss the current state of the art with regard to both beneficial and harmful roles of histones and also their possible use as biomarkers and therapeutic targets.

Consenso argentino en gestión efectiva de clínicas de anticoagulación para uso de antagonistas de la vitamina K / Argentine consensus in effective management of anticoagulation clinics for the use of vitamin K antagonists

Resumen El tratamiento de un paciente anticoagulado con antagonistas de la vitamina K (AVK) sigue siendo un desafío, especialmente en regiones donde, por el costo, los dicumarínicos son todavía la alternativa más buscada a la hora de elegir un anticoagulante oral. Las clínicas de anticoagulación han demostrado ser la forma más eficiente y segura de evitar complicaciones trombóticas y hemorrágicas y de mantener al paciente en rango óptimo de tratamiento. Sin embargo, requieren de una adecuada infraestructura y personal capacitado para que funcionen eficientemente. En este consenso argentino se propone una serie de parámetros para la gestión efectiva de una clínica de anticoagulación. El objetivo es lograr una elevada calidad desde el punto de vista clínico-asistencial a través de un laboratorio de hemostasia de excelencia. Los criterios desarrollados en el documento fueron consensuados por un amplio grupo de expertos especialistas en hematología y en bioquímica de todo el país. Estos criterios deben adaptarse a la irregular disponibilidad de recursos de cada centro, pero siempre se los debe tener en cuenta a la hora de indicar el tratamiento anticoagulante con estas drogas. Tener en consideración estas premisas nos permitirá optimizar la atención del enfermo anticoagulado con AVK y de esta forma minimizar las intercurrencias trombóticas y hemorrágicas a las que está expuesto, para así honrar nuestra promesa de no dañar al paciente.

Abstract Treating an anticoagulated patient with vitamin K antagonists (VKA) remains a challenge, especially in areas where dicoumarins are still the first drug of choice due to the cost of other oral anticoagulants. Anticoagulation clinics have proven to be the most efficient and safe way to avoid thrombotic and hemorrhagic complications and to keep patients in optimal treatment range. However, they require adequate infrastructure and trained personnel to work properly. In this Argentine consensus we propose a series of guidelines for the effective management of the anticoagulation clinics. The goal is to achieve the excellence in both the clinical healthcare and the hemostasis laboratory for the anticoagulated patient. The criteria developed in the document were agreed upon by a large group of expert specialists in hematology and biochemistry from all over the country. The criteria presented here must always be considered when indicating VKA although they had to be adapted to the unequal reality of each center. Taking these premises into consideration will allow us to optimize the management of the anticoagulated patient with VKA and thus minimize thrombotic and hemorrhagic intercurrences, in order to honor our promise not to harm the patient.

The -308 G/A polymorphism in the tumor necrosis factor-α gene is not associated with development and progression of rheumatoid arthritis in Argentinean patients.

AIM: A polymorphism in the tumor necrosis factor-alpha (TNF-α) promoter region has been associated with disease susceptibility and progression in rheumatoid arthritis (RA). The presence of an adenosine (TNF2 allele) instead of a guanine (TNF1 allele) at position -308 may be responsible for a general increase in the transcriptional activity of the TNF-α gene. Our aim was to evaluate the association of the TNF2 allele with the risk of disease development and/or progression of RA in an Argentine population cohort. METHODS: Two hundred and twenty-three consecutive patients with RA according to the 1987 criteria of the American College of Rheumatology were included in the study. Clinical variables, Disease Activity Score 28, Health Assessment Questionnaire and Rheumatoid Arthritis Quality of Life were recorded. The radiographic erosions were determined by the method of Sharp/van der Heijde. A group of 111 healthy subjects matched by sex and age was used as a control. All samples were genotyped for the -308 G/A TNF-α polymorphism. RESULTS: No significant differences were observed either in the frequency of the TNF2 allele or in the genotypic distributions of the -308 G/A TNF-α polymorphism (P > 0.05) between the control group and the RA patients. No association was found between the TNF2 allele and the variables related to the course and outcome of the disease (P > 0.05). CONCLUSION: In this cohort of Argentinean patients with RA, the TNF2 allele was neither associated with susceptibility to the disease nor was it associated with the variables related to the course and outcome of the disease.

4G/5G plasminogen activator inhibitor-1 and -308 A/G tumor necrosis factor-α promoter gene polymorphisms in Argentinean lupus patients: focus on lupus nephritis.

We investigated the relationship between the 4G/5G plasminogen activator inhibitor (PAI-1) and -308 A/G tumor necrosis factor-α (TNF-α) polymorphisms and the clinical and biochemical features of systemic lupus erythematosus (SLE) in an Argentinean patient cohort. A total of 402 patients were studied, including 179 SLE patients and 223 healthy individuals. PCR-RLFP was used to determine the genotypes of the 4G/5G PAI-1 and -308 A/G TNF-α polymorphisms. SLE patients with lupus nephritis (LN) (n = 86) were compared with patients without LN (n = 93). Additionally, LN patients were divided into proliferative LN and non-proliferative LN groups according to the results of the renal biopsies. No significant differences were noted in the genotype distributions or allele frequencies of these TNF-α and PAI-1 polymorphisms between SLE patients and controls. There were higher numbers of criteria for SLE, more lupus flares and higher damage scores in LN patients, but there were similar frequencies of anti-phospholipid antibody (APA) positivity and anti-phospholipid syndrome. No significant difference was noted for any studied variable between the proliferative LN and non-proliferative LN groups except for the presence of APA. We found no significant differences in the TNF-α and PAI-1 genotype distributions or allele frequencies between groups. We found that the -308 A/G TNF-α and 4G/5G PAI-1 polymorphisms are not associated with susceptibility to SLE in an Argentinean population. We also did not find any association between the presence of any specific allele or genotype and the development of LN in SLE patients. Finally, no association was noted between either of the two polymorphisms and the severity of renal disease.

Anexinas y pérdidas recurrentes de embarazo / Annexins and recurrent pregnancy loss

Las pérdidas de embarazo recurrentes (PER), afectan a la salud pública y comprometen en forma directa la calidad de vida de cientos de mujeres, con detrimento de su salud física y psíquica. Aproximadamente un 50% de las PER no se asocian a alguna de las etiologías conocidas, y por lo tanto se consideran idiopáticas. Recientemente se ha demostrado que la expresión de la anexina 5 (ANXA5), una proteína ubicada en la superficie trofoblástica, juega un papel fundamental en el mantenimiento del embarazo ya que cumple un rol como inmunomodulador y anticoagulante a nivel de la placenta. Algunos haplotipos genéticos de la ANXA5 se asocian a alteraciones en la expresión de este gen, como el haplotipo M2 que se vincula a una reducción en la expresión de la ANXA5. La presencia de dicho haplotipo se relaciona con los siguientes eventos del embarazo: PER, restricción del crecimiento fetal intrauterino, bajo peso al nacer, preclampsia y tromboembolismo pulmonar materno. Esta revisión describe la estructura, función y expresión genética de la ANXA5, así como también su posible implicancia en la PER.

Recurrent Pregnancy Loss (RPL) affects public health and directly compromises the quality of life of hundreds of women, with a detrimental effect on their physical and mental health. Approximately 50% of RPL are not associated to any of the currently known etiology and will be considered idiopathic. Recently, it has been demonstrated that the expression of annexin 5 (ANXA5), a protein found on the trophoblastic surface, plays a fundamental role in the development of pregnancy due to its immunomodulator and anticoagulant function at the placentary level. Some genetic haplotypes of ANXA5 are associated to alterations in the expression of this gene, such as haplotype M2 which is associated to a decrease in the expression of ANXA5. The presence of this haplotype is related to the following conditions occurring during pregnancy: RPL, foetal intrauterine growth restriction, low child weight at birth, preeclampsia and maternal pulmonary thromboembolism. This review describes the structure, function and genetic expression of ANXA5, as well as its possible implication in RPL.

Biomarkers in sepsis at time zero: intensive care unit scores, plasma measurements and polymorphisms in Argentina.

INTRODUCTION: A patient's response to sepsis is influenced by their genetic background. Our objective was to use plasma markers, such as protein C (PC), D-dimer, Plasminogen Activator Inhibitor-1 (PAI-1) levels, and the PAI-1 rs1799889 4G/5G and  Tumor Necrosis Factor-α rs1800629 G/A  polymorphisms to improve classical intensive care unit (ICU) scores. METHODOLOGY: We studied 380 subjects, 166 with sepsis. We performed coagulation tests: plasma PAI-1 and PC levels were evaluated by chromogenic methods; and D-dimer was evaluated by immunoturbidimetric assay. Polymorphisms were performed using for polymerase chain reactions followed by digest with specific restriction enzyme. We acquired the APACHE and SOFA scores (time zero), sex, age, body mass index, associated co-morbidities, length of ICU stay (days), the severity of sepsis (sepsis, severe sepsis or septic shock), the HIV status and the ICU outcome (survival or death). RESULTS: We found significant differences between patients who died (n=80) and those who survived (n=86) in terms of the ICU length of stay (6 vs. 10 days), septic shock (64 versus 24%), age (51 versus 38 years old), HIV+ condition (34 versus 16%), SOFA (7 versus 4), APACHE (19 versus 13), D-dimer (4.32 versus 2.88 mg/ml), PC (46.0 versus 63.5 %) and PAI-1 (33.0 versus 16.5 UA/l). When we used a regression analysis with dichotomized variables, only the SOFA4, PAI-116, HIV status and the PAI-1 4G allele proved to be predictors of death at time zero. CONCLUSIONS: In the future, ICU scores may be further improved by adding certain genomic or plasma data. 

Role of -675 4G/5G in the plasminogen activator inhibitor-1 gene and -308G/A tumor necrosis factor-α gene polymorphisms in obese Argentinean patients.

AIM: Plasminogen activator inhibitor-1 (PAI-1) and tumor necrosis factor-α (TNF-α) are increased in the circulation of obese persons. Because a direct link between PAI-1 and TNF-α in obesity has been observed, they are candidate genes for the development of obesity. We sought to evaluate the relation between the genotypic and allelic frequencies of the -675 4G/5G PAI-1 and -308 G/A TNF-α polymorphisms and their association with the risk for obesity in an Argentinean population. METHODS: A group of 110 consecutive obese persons and a group of 111 lean controls were recruited. Polymerase chain reaction was used to determine the frequency of PAI-1 and TNF-α polymorphisms; serum fasting glucose, insulin, and lipid levels were measured by standard methods. Insulin sensitivity was evaluated by using homeostasis model assessment. RESULTS: The -308 TNF-α and -675 4G/5G PAI-1 genotype distribution did not significantly differ between the groups (p=0.544 and p=0.327, respectively). Homeostasis model assessment was the only positive independent determinant of body mass index (R(2)=0.493; p<0.001). CONCLUSION: The -675 4G/5G PAI-1 and the -308 TNF-α polymorphism variants tested in this study, individually or combined, were not associated with obesity in an Argentinean population.

[Insulin-like growth factor-binding protein-1: a new biochemical marker of nonalcoholic fatty liver disease?]. / La proteína transportadora del factor de crecimiento insulínico tipo 1: un nuevo marcador para la enfermedad hepática grasa no alcohólica?

AIM: to assess the presence of nonalcoholic fatty liver disease in patients with risk factors for this pathology (obesity, dyslipidemia, metabolic syndrome and diabetes type 2) and to determine the role of insulin, HOMA index, insulin-like growth factor-binding protein-1, sex hormone-binding globulin and plasminogen activator inhibitor type 1, as biochemical markers. METHODS: Ninety-one patients with risk factors for nonalcoholic fatty liver disease were evaluated. Serum transaminases, insulin, sex hormone-binding globulin, insulin-like growth factor-binding protein-1 and plasminogen activator inhibitor type 1 were measured. The diagnosis of fatty liver was performed by ultrasonography and liver biopsies were performed to 31 subjects who had steatosis by ultrasonography and high alanine aminotransferase. RESULTS: Nonalcoholic fatty liver disease was present in 65 out of 91 patients (71,4%). Liver biopsy performed to 31 subjects confirmed nonalcoholic steatohepatitis. Twenty-five patients had different degrees of fibrosis. Those individuals with fatty liver had higher waist circumference, serum levels of triglycerides, insulin and HOMA index, and lower serum insulin-like growth factor-binding protein-1 concentration. The degree ofhepatic steatosis by ultrasonography was positively correlated to waist circumference, triglycerides, insulin and HOMA index (p<0,003; p<0,003; p<0,002 and p<0,001, respectively), and was negatively correlated to HDL-cholesterol and insulin-like growth factor-binding protein-1 (p<0,025 and p<0,018, respectively). CONCLUSIONS: We found a high prevalence of NAFLD in patients with risk factors, most of them overweight or obese. Although SHBG and PAI-1 have a closely relationship to insulin resistance, they did not show to be markers of NAFLD. Regardless of low IGFBP-1 levels associated with NAFLD, serum IGFBP-1 measure is less accessible than insulin and triglycerides levels, HOMA index and waist circumference. Moreover, it is not a better marker for NAFLD than the above mentioned.

Plasma plasminogen activator inhibitor-1 levels and nonalcoholic fatty liver in individuals with features of metabolic syndrome.

Fatty liver represents the liver component of metabolic syndrome and may be involved in plasminogen activator inhibitor-1 (PAI-1) synthesis. We studied plasma PAI-1 levels and relationships with risk factors for metabolic syndrome, including fatty liver, in 170 patients. Liver ultrasound scan was performed on all patients, and a liver biopsy was performed on those patients with chronically elevated transaminase levels. Plasma PAI-1 levels correlated significantly (P < .05) with body mass index, degree of steatosis, insulin resistance, insulin level, waist circumference, triglycerides, and high-density lipoprotein (HDL) -cholesterol. However, only body mass index (beta = .455) and HDL-cholesterol (beta = .293) remained predictors of PAI-1 levels. Liver biopsy revealed a significant correlation (P < .05) between insulin resistance (r = 0.381) or insulin level (r = 0.519) and liver fibrosis. In patients presenting features of metabolic syndrome, plasma PAI-1 levels were mainly conditioned by the whole-body fat content.

[Plasma homocysteine in human immunodeficiency virus infected patient]. / Homocisteína plasmatica en infectados con el virus de la inmunodeficiencia humana.

UNLABELLED: Weak hyperhomocysteinemia is a risk factor for the development of atherothrombotic vascular complication. Their plasma levels are affected by nutritional and pharmacologic factors, tobacco, certain metabolic state and gender. In HIV+ patients, the wasting syndrome or chronic diarrheas could affect the levels of homocysteine (Hcy), as well as some adverse effects of the new antiretroviral therapies (lipodystrophy syndrome: insulin resistance and/or dislypemia). The levels of Hcy were evaluated in 53 HIV+ patients without any treatment and in 75 HIV+ under treatment with and without metabolic disturbances (n = 43; n = 32, respectively). CONTROL GROUP: 32 HIV negative individuals. We looked for association with folic acid, vitamin B12, lipids, insulin resistance status, activation platelets (soluble P-selectin) and endothelial injury (soluble trombomodulin) markers; and also their relation with tobacco, disease status and kind of treatment. There were no statistically significant differences in the mean levels of vitamin B12, Hcy, P-selectin and insulin resistance status between the control group and the HIV+; 16.4% of the 128 HIV+ patients had Hcy > or = 15 mumol/L and the control group had 12.9% (p = 0.617). The levels of Hcy correlated with the levels of folic acid (Rho = -0.314, p < 0.01) and age (Rho = 0.277, p < 0.01) among HIV+. There were no statistically significant differences in the levels of Hcy neither between smokers and non smokers (p = 0.452) nor between HIV+ AIDS or HIV+ no AIDS (p = 0.774) nor with the use of certain antiretrovirals (p = 0.801). The hyperhomocysteinemia (a well known atherothrombotic risk factor) is not frequently associated with HIV infected patients. The levels of Hcy would not seem to be influenced either by the HIV condition or by the antiretroviral treatments or their adverse effects.

Viral load and disease progression as responsible for endothelial activation and/or injury in human immunodeficiency virus-1-infected patients.

The endothelium participates in haemostasis, inflammation, blood pressure regulation and other physiological systems. Consequently, endothelial dysfunction has been related to hypertension, thrombosis and atherosclerosis. Both von Willebrand factor (vWF) and tissue-type plasminogen activator (t-PA) are synthesized by the endothelium and their plasma levels increased during endothelium activation or injury. So far, they are well-known markers of endothelial cell function. Many circumstances activate or damage the endothelium, such as viruses, bacterium and inflammation. Circulating vWF and t-PA were studied in 92 unselected human immunodeficiency virus-1 (HIV-1)-infected patients [27 patients with and 65 patients without acquired immunodeficiency syndrome (AIDS)] and correlated with plasma levels of pro-inflammatory cytokines (tumour necrosis factor-alpha, interleukin-6), viral load, CD4 T-cell count and infectious status. HIV-1-infected patients had significantly higher plasma levels of vWF (152 versus 90%), tumour necrosis factor-alpha (31.3 versus 9.0 pg/ml) and interleukin-6 (3.5 versus 1.9 pg/ml) but not t-PA (5.9 versus 4.2 ng/ml) than the control group. These two endothelial markers correlated significantly with viral load and interleukin-6 levels in HIV-1-infected patients. The highest levels of vWF and t-PA were found in patients with AIDS. In conclusion, endothelial cell perturbation is present in HIV infection and may be a consequence of different mechanisms such as viral load, cytokines and advanced diseases.

Baja prevalencia de anticuerpos antifosfolípidos autoinmunes en enfermedades hepáticas / Low prevalence of autoimmune antiphospholipid antibodies in hepatic diseases

Antiphospholipid antibodies (aPL) have been associated with different diseases. They are defined as a large family of immunoglobulins (Ig) of either alloantibodies or autoantibodies. The autoimmune antibodies are associated with venous and/or arterial thrombosis, thrombocytopenia and recurrent fetal loss in the so-called antiphospholipid syndrome or in systemic lupus erythematosus. These antibodies are directed against proteins or phospholipid-protein complexes. On the contrary, antiphospholipid antibodies (alloantibodies) which are found in infectious diseases sera (syphilis, HIV, and other viral diseases), disappear with illness remission and are directed to phospholipids alone (particularly cardiolipin) and are not associated with thrombosis or recurrent fetal loss. However, the role and type of aPL found during hepatic diseases is still unclear. To investigate the prevalence of autoimmune aPL (IgG and IgM) during different hepatic diseases, we have studied 128 patients with hepatitis C virus, hepatitis B virus and hepatic autoimmune diseases without treatment as well as 40 healthy control subjects. We have used a specific ELISA kit, that uses a mixture of phospholipid instead of cardiolipin alone, and allows a better detection of aPL of the autoimmune type. Our results show that autoimmune aPL are not significantly increased in viral hepatic diseases (2%) or autoimmune diseases of the liver (3%) when compared to the control group (0%).