Exacerbation of oxidative stress during sickle vaso-occlusive crisis is associated with decreased anti-band 3 autoantibodies rate and increased red blood cell-derived microparticle level: a prospective study.

Painful vaso-occlusive crisis, a hallmark of sickle cell anaemia, results from complex, incompletely understood mechanisms. Red blood cell (RBC) damage caused by continuous endogenous and exogenous oxidative stress may precipitate the occurrence of vaso-occlusive crises. In order to gain insight into the relevance of oxidative stress in vaso-occlusive crisis occurrence, we prospectively compared the expression levels of various oxidative markers in 32 adults with sickle cell anaemia during vaso-occlusive crisis and steady-state conditions. Compared to steady-state condition, plasma levels of free haem, advanced oxidation protein products and myeloperoxidase, RBC caspase-3 activity, as well as the concentrations of total, neutrophil- and RBC-derived microparticles were increased during vaso-occlusive crises, whereas the reduced glutathione content was decreased in RBCs. In addition, natural anti-band 3 autoantibodies levels decreased during crisis and were negatively correlated with the rise in plasma advanced oxidation protein products and RBC caspase-3 activity. These data showed an exacerbation of the oxidative stress during vaso-occlusive crises in sickle cell anaemia patients and strongly suggest that the higher concentration of harmful circulating RBC-derived microparticles and the reduced anti-band 3 autoantibodies levels may be both related to the recruitment of oxidized band 3 into membrane aggregates.

CAREST--Multilingual Regional Integration for Health Promotion and Research on Sickle Cell Disease and Thalassemia.

Sickle cell disease (SCD) is a significant problem in the Caribbean, where many individuals have African and Asian forebears. However, reliable prevalence data and specific health care programs for SCD are often missing in this region. Closer collaboration between Caribbean territories initiated in 2006 to set up strategies to promote better equity in the health care system for SCD patients led to the formation of CAREST: the Caribbean Network of Researchers on Sickle Cell Disease and Thalassemia. We present the effectiveness of collaborations established by CAREST to promote SCD newborn screening programs and early childhood care, to facilitate health worker training and approaches for prevention and treatment of SCD complications, and to carry out inter-Caribbean research studies.

Hepatitis C virus antibodies and other markers of blood-transfusion-transmitted infection in multi-transfused Cuban patients.

BACKGROUND: HCV was initially identified in 1989 when it was found to be the primary causative agent of non-A, non-B hepatitis,a condition associated with high rates of progressive and end-stage liver disease, cirrhosis, and hepatocellular carcinoma. Since then, appreciation of the significant worldwide health impact of HCV infection has grown. HCV infection was identified as a public health problem in Cuba in the 1990s. Despite universal blood donor screening, which was achieved in 1995 using the Cuban immunoassay system UMELISA HCV, the infection is still found in multi-transfused patients. OBJECTIVES: To determine the magnitude of HCV, HBV and HIV-1&2 infections among Cuban blood recipients and to assess the role of potential risk factors. STUDY DESIGN: Cross-sectional study of 318 patients from Havana City, Pinar del Río and Villa Clara, who had been previously treated with 10 or more units of allogenic blood or blood components in at least two different occasions. The patients were evaluated for HCV Ab, HBsAg, anti-HBc Ab, and HIV-1&2 Ab. Data management and statistical analysis were performed using EpiInfo and SSPS software. RESULTS: Prevalence rates were 51.6% for HCV Ab; 5.3% for HBsAg; 45.0% for anti-HBc and 0% for HIV-1&2 Ab. Ten (3.1%) patients were co-infected with HCV and HBV Blood transfusion was not identified as the main risk factor for HCV transmission. The number of blood units received by the patients was not statistically associated with the HCV Ab prevalence. CONCLUSIONS: Infection with HCV was identified more frequently than HBV and HIV among our study population. Patients undergoing hemodialysis were at the highest risk of becoming infected. Medical procedures including surgery, transplantation, invasive odontology, and sharing or reuse of needles and syringes, are associated with higher HCV Ab seroprevalences compared with blood transfusion alone.

[Endothelial adhesion molecules ICAM-1, VCAM-1 and E-selectin in patients with acute coronary syndrome]. / Moléculas de adhesión endoteliales ICAM-1, VCAM-1 y E-selectin en pacientes con síndrome coronario agudo.

INTRODUCTION AND OBJECTIVES: The acute inflammatory response is an important phenomenon in the pathogenesis of myocardial damage during acute coronary syndrome. Endothelial dysfunction has been found in unstable angina and acute myocardial infarction, although the results are controversial. The purpose of this study was to determine the levels of the soluble endothelial adhesion molecules ICAM-1, VCAM-1 and E-selectin, in patients with unstable angina and acute myocardial infarction, compare the results in both groups, and analyze their relation with the degree of myocardial injury. METHODS: Serum concentrations of ICAM-1, VCAM-1, and E-selectin were measured in 37 control subjects and 43 patients (32 with acute myocardial infarction and 11 with unstable angina). Measurements were made at the time of admission and ten days later using commercial enzyme-linked immunoabsorbent assay (ELISA) kits (R&D Systems, UK). RESULTS: There was a significant increase in E-selectin (p < 0.05) in patients with unstable angina at admission and ten days later. In contrast, patients with acute myocardial infarction showed no significant differences in E-selectin compared with the control group at admission or ten days later. A significant increase in VCAM-1 levels was demonstrated in both groups of patients and ICAM-1 levels in acute myocardial infarction, but the concentrations of VCAM-1 and ICAM-1 in both groups of patients at admission and ten days later did not differ significantly. There was no relation between soluble endothelial adhesion molecule levels and the severity of myocardial damage estimated by cardiac enzymes or electrocardiographic changes. CONCLUSION: This study indicates that serum levels of E-selectin, measured at time of admission and ten days later, could be a marker for unstable angina and might be useful in the differential diagnosis with myocardial infarction.

Natural antiband 3 antibodies in patients with sickle cell disease.

Band 3 oligomers, precociously formed in the membrane of sickle red blood cells (SS RBC) as a result of oxidative damage, induce two significant changes: (1) contribution to the adhesive nature of these cells to endothelial cells; (2) production of recognition sites for natural antiband 3 antibodies (antiband 3 Nabs). The inhibition of the adhesion of SS RBC to endothelial cells by band 3 peptides suggests a participation of antiband 3 Nabs in the etiology and prevention of vaso-occlusive crises (VOC). To address this question, we measured the levels of antiband 3 Nabs in sickle cell anaemia (SCA) patients (45 in steady state, 35 in VOC) and in controls (27 sickle trait, 30 normal AA subjects). A significant decreased of antiband 3 Nabs in the VOC group was demonstrated as compared with the steady state group, the sickle trait and healthy controls. This study provides data suggesting that Antiband 3 Nabs are likely to play a role in the SCA VOC.

Activación del sistema complemento e inmunocomplejos circulantes en la anemia drepanocítica / Activation of complement system and circulating immune complexes in sickle cell anemia

Se estudió la actividad del sistema complemento así como la presencia de inmunocomplejos circulantes (ICC) en 61 pacientes con anemia drepanocítica (AD) distribuidos en 4 grupos según sus manifestaciones clínicas: condiciones basales, crisis vasooclusivas, crisis hepáticas y crisis aplástica. Se encintraron diferencias significativas entre la actividad hemolítica de la vía alternativa y el factor B en todos los enfermos en relación con los sujetos sanos; se correlacionaron estos parámetros con niveles bajos de C3. Se demostraron ICC en los grupos en crisis, no asociados con la actividad de la vía clásica, excepto en el grupo de crisis aplástica. En este último, la actividad de la vía clásica se correlacionó significativamente con las concentraciones de C3 y C4. Se discuten las posibles causas de las alteraciones observadas en el sistema complemento, así como la participación de los ICC en los diferentes estadios estudiados en la AD

Uso de la exanguinotransfusión y la plasmaferesis en las crisis hepáticas de la anemia drepanocítica / Use of exsanguination transfusión and plasmapheresis in the hepatic crisis of sickle cell anemia

En 4 pacientes con anemia drepanocítica en crisis hepática se demostró la presencia de inmunocomplejos circulantes. En 2 pacientes se empleó la exanguinotransfusión, en otro plasmaféresis y en el cuarto se utilizaron ambos procedimientos terapéuticos. En todos los casos se obtuvo una evolución favorable de la función hepática