Post-transfusion purpura is a rare bleeding disorder characterized by severe and sudden thrombocytopenia within 3-12 days after blood transfusion. Typically, preformed antibodies directed against human platelet antigens, especially HPA-1a, are associated with the clinical symptoms. A 46-year-old female presenting to the hospital with acute progressive kidney insufficiency and anaemia received t...

The objective of this study was to compare the sensitivity and specificity of lymphocytotoxicity test (LCT), solid phase red cell adherence assay (SPRCA) and flow cytometry in detecting platelet reactive antibodies against human leukocyte antigens (HLA) class I and human platelet antigens (HPA). Sera from 38 thrombocytopenic patients and 5 mothers of thrombocytopenic newborns were screened for ...

BACKGROUND Alloimmunization against human platelet antigens (HPAs) during pregnancy is rare but can lead to severe bleeding disorders, such as fetal and neonatal alloimmune thrombocytopenia. STUDY DESIGN AND METHODS In a cohort of 241 uncomplicated pregnancies, we investigated the immunogenicity of HPA mismatches and correlated HLA sensitization with HPA antibody formation. HPA antibodies wer...

Haematologica vol. 85(4):April 2000 3. Simsek S, Faber NM, Bleeker PM, et al. Determination of human platelet antigen frequencies in the Dutch population by immunophenotyping and DNA (allele-specific restriction enzyme) analysis. Blood 1993; 81:835-40. 4. Tazzari PL, Cirillo D, Bontadini A, Ricci F, Masi R, Conte R. Flow cytometry immunophenotyping and polymerase chain reaction-site-specific pr...

The pathogenesis and tissue damage that accompanies destruction of platelets in immune thrombocytopenias (IT) is still not understood very well and in addition to platelets, other cells (e.g. endothelial cells, CD34+ hematopoietic stem/progenitors) may also become affected. Based on our previous work that platelet antigens (e.g., CD41) may be transferred by platelet-derived microvesicles (PMV) ...

Over the last decades the progressive increase in platelet use has coincided with increasingly aggressive myelosuppressive therapy for malignancies or allogeneic hematopoietic stem cell transplantation. The US National Marrow Donor Program predicts a doubling in allogeneic transplants between 2010 and 2015 (1). More than three million Brazilian donors were registered in the Bone Marrow Donors W...

In this paper, the satellite intermodulation is evaluated in frequency domain, for N-carrier input. Fourier transform is applied to avoid large equations where the number of carriers is quite low. The algorithm is probed with well-known series for particular cases with two input carriers. Additionally, it is also possible to evaluate AM-AM conversion in a large set of input carriers. Key-Words:...

A single nucleotide polymorphism in the integrin α2 gene ITGA2 (rs1801106; G1600A) creates the non-conservative amino acid substitution E534K, the basis of the human platelet alloantigen system HPA-5. Yet HPA-5 alleles do not influence binding of α2β1 to its primary ligand collagen I, and the effect of HPA-5 on platelet function has not been determined. We used a direct platelet adhesion assay ...

Fetal/neonatal alloimmune thrombocytopenia (F/NAIT) is the most frequent cause of haemorrhagic morbidity and mortality in otherwise healthy term infants and occurs in 1 in 1000 to 1 in 2000 pregnancies [1]. Maternal HPA-1a alloimmunization is responsible for the majority of NAIT [1], and only a few cases of NAIT caused by anti-HPA-3a have been published [2–4]. However, based on gene frequencies...