Association of the immature platelet fraction with sepsis diagnosis and severity.

Management of Sepsis would greatly benefit from the incorporation of simple and informative new biomarkers in clinical practice. Ideally, a sepsis biomarker should segregate infected from non-infected patients, provide information about prognosis and organ-specific damage, and be accessible to most healthcare services. The immature platelet fraction (IPF) and immature reticulocyte fraction (IRF) are new analytical parameters of the complete blood count, that have been studied as biomarkers of several inflammatory conditions.

Platelet antibody detection by flow cytometry: an effective method to evaluate and give transfusional support in platelet refractoriness.

Background: Immune platelet refractoriness is mainly caused by human leukocyte antigen antibodies (80-90% of cases) and, to a lesser extent, by human platelet antigen antibodies. Refractoriness can be diagnosed by laboratory tests and patients should receive compatible platelet transfusions. A fast, effective and low cost antibody-screening method which detects platelet human leukocyte/platelet antigen antibodies is essential in the management of immune platelet refractoriness.

Reduced thrombin formation and excessive fibrinolysis are associated with bleeding complications in patients with dengue fever: a case-control study comparing dengue fever patients with and without bleeding manifestations.

Background: Dengue cases have been classified according to disease severity into dengue fever (DF) and dengue hemorrhagic fever (DHF). Although DF is considered a non-severe manifestation of dengue, it has been recently demonstrated that DF represents a heterogeneous group of patients with varied clinical complications and grades of severity. Particularly, bleeding complications, commonly associated to DHF, can be detected in half of the patients with DF.

Measuring red blood cell aggregation forces using double optical tweezers.

Classic immunohematology approaches, based on agglutination techniques, have been used in manual and automated immunohematology laboratory routines. Red blood cell (RBC) agglutination depends on intermolecular attractive forces (hydrophobic bonds, Van der Walls, electrostatic forces and hydrogen bonds) and repulsive interactions (zeta potential). The aim of this study was to measure the force involved in RBC aggregation using double optical tweezers, in normal serum, in the presence of erythrocyte antibodies and associated to agglutination potentiator solutions (Dextran, low ionic strength solution [LISS] and enzymes).

The new noninvasive occlusion spectroscopy hemoglobin measurement method: a reliable and easy anemia screening test for blood donors.

Background: The tests used for anemia screening in blood donors are based on fingerstick samples, leading to discomfort and complaints. The aim of this study was to analyze the feasibility of occlusion spectroscopy method in blood banks and to compare the method with fingerstick hemoglobinometer and hemoglobin (Hb) determination on an automatic blood analyzer.

Study Design And Methods: The study enrolled 205 consecutive volunteer blood donors.

Platelet associated IgG may be related with thrombocytopenia in patients with myelodysplastic syndromes.

Thrombocytopenia is common in patients with myelodysplastic syndromes (MDS) and immune destruction of platelets could be an important factor for its occurrence. We prospectively analyzed platelet-associated IgG (PAIgG) through platelet immunofluorescence test (PIFT), mean platelet volume (MPV), platelet size deviation width (PDW) and glycocalicin index (GCI) of 54 patients with MDS, classified according to the International Prognostic Scoring System (IPSS). Thrombocytopenia (platelet count<100×10(9)/L) was correlated with a higher amount of PAIgG, significantly higher MPV and increased GCI.

Diagnosis of Scott syndrome in patient with bleeding disorder of unknown cause.

Scott syndrome is a rare bleeding disorder due to an impaired exposure of phosphatidilserine on the platelet membrane, compromising the platelet procoagulant activity, thrombin generation and, thus, the clot formation. We report a case of a 17-year-old female adolescent with bleeding episodes of unknown cause. She had normal coagulation, but altered platelet aggregation under arteriolar flow, indicating platelet dysfunction.

Identification of platelet refractoriness in oncohematologic patients.

Objectives: To identify the occurrence and the causes of platelet refractoriness in oncohematologic patients.

Introduction: Platelet refractoriness (unsatisfactory post-transfusion platelet increment) is a severe problem that impairs the treatment of oncohematologic patients and is not routinely investigated in most Brazilian services.

Methods: Forty-four episodes of platelet concentrate transfusion were evaluated in 16 patients according to the following parameters: corrected count increment, clinical conditions and detection of anti-platelet antibodies by the platelet immunofluorescence test (PIFT) and panel reactive antibodies against human leukocyte antigen class I (PRA-HLA).

Fetal genotyping for platelets antigens: a precise tool for alloimmune thrombocytopenia: case report and literature review.

Introduction: Maternal-fetal alloimmune thrombocytopenia complicates about 0.1% of all pregnancies and is associated with major fetal and neonatal morbidity and mortality, especially spontaneous central nervous system bleeding leading to death and neurological handicaps. Successful prevention and treatment depend on the identification of at-risk possible carriers of anti-platelet antibodies.

A novel association of acquired ADAMTS13 inhibitor and acute dengue virus infection.

Background: Dengue is a mosquito-borne viral disease with an increasing incidence worldwide. Thrombocytopenia is a common finding in dengue virus (DV) infection; however, the underlying mechanisms remain unknown.

Case Report: Here we provide the first evidence of a case of antibody formation against ADAMTS13 (ADAMTS13 inhibitor) in the course of a severe acute DV infection resulting in thrombotic microangiopathy (TMA).

The relationship between ABO groups and subgroups, factor VIII and von Willebrand factor.

The aim of this study was to correlate ABO groups with plasma levels of factor VIII (FVIII), von Willebrand factor (VWF:Ag), and ristocetin cofactor (VWF:RCo). Serological and molecular tests defined blood groups from 114 donors (10 AA, 10 BB, 10 AB, 10 AO1, 10 BO1,16 O1O1, 20 A2O1, 20 A2B, 4 A3O1, 3 AxO1, and 1 BelO1). The levels of VWF:Ag, FVIII and VWF:RCo observed in rare subgroups (A3O1, AxO1, BelO1) were similar to the values found in the O1O1 group.

A prospective study on the prevalence and risk factors for neonatal thrombocytopenia and platelet alloimmunization among 9332 unselected Brazilian newborns.

Background: Neonatal thrombocytopenia (NT) occurs in 0.5 to 0.9% of unselected Caucasian newborns.

Pancytopenia in untreated patients with Graves' disease.

Severe pancytopenia is a rare but severe complication of thyrotoxicosis. In this report, we describe four patients with Graves' disease who presented with pancytopenia at diagnosis. Methimazole (30-40 mg/d) or propylthiouracil (400 mg/d) restored normal hematopoiesis in three of the patients.

Investigation of red blood cell antigens with highly fluorescent and stable semiconductor quantum dots.

We report a new methodology for red blood cell antigen expression determination by a simple labeling procedure employing luminescent semiconductor quantum dots. Highly luminescent and stable core shell cadmium sulfide/cadmium hydroxide colloidal particles are obtained, with a predominant size of 9 nm. The core-shell quantum dots are functionalized with glutaraldehyde and conjugated to a monoclonal anti-A antibody to target antigen-A in red blood cell membranes.

Genetic variability of platelet glycoprotein Ibalpha gene.

Platelet membrane glycoprotein (GP) Ibalpha is a critical component of platelet adhesion complex to subendothelium structures following tissue injury or pathological surfaces, such as atherosclerotic plaques. Polymorphisms of the GPIbalpha gene have been associated with a high risk for occlusive vascular disease, and its distribution varies considerably among distinct populations. These polymorphisms comprise the human platelet antigen (HPA)-2 system, the -5C/T dimorphism of the Kozak sequence, and the variable number of tandem 39-bp repeats (VNTR).

The Gly972Arg polymorphism in insulin receptor substrate-1 is associated with decreased birth weight in a population-based sample of Brazilian newborns.

Objective: We studied the association between the Gly972Arg polymorphism in insulin receptor substrate-1 (IRS-1) and birth weight in a population-based sample of Brazilian newborns.

Research Design And Methods: We studied 194 newborn children with adequate gestational age to identify the association between the Gly972Arg polymorphism and birth weight using PCR-restriction fragment length polymorphism analysis.

Results: The data showed that the birth weight was lower in the newborns with the Gly972Arg polymorphism in IRS-1 compared with control subjects (3,141 +/- 31.