ABSTRACT
The detection of the most significant erythrocyte antigens present in each one of the individuals is fundamental when carrying out a transfusion or a transplant. Detection to date is performed by conventional serological methods through the antigen-antibody reaction. But several drawbacks may arise depending on the pathology under study, limiting the availability of blood components. Molecular methods such as genotyping is a tool that complements sensitivity and specificity and has come to revolutionize immunohematology in the blood bank, allowing not only the detection of erythrocyte antigens but also platelet antigens. These methodologies are applicable in patients and in large-scale donors, starting from the allelic variants present in each of the genes that code for the antigens of clinical interest, using microarray systems or systems based on particles labeled with specific probes or their variants that allow an analysis from the immunohematological point of view.
La detección de los antígenos eritrocitarios más significativos presentes en cada uno de los individuos es fundamental cuando se lleva a cabo una transfusión o un trasplante. La detección a la fecha se realiza mediante métodos serológicos convencionales a través de la reacción de antígeno-anticuerpo. Pero se pueden presentar varios inconvenientes dependiendo de la patología en estudio, lo cual limita la disponibilidad de los hemocomponentes. Los métodos moleculares, como la genotipificación, son una herramienta que complementa la sensibilidad y especificidad y que han venido a revolucionar la inmunohematología en el banco de sangre, lo cual permite no solo la detención de antígenos eritrocitarios sino también la de antígenos plaquetarios. Estas metodologías son aplicables en pacientes y en donantes a gran escala, partiendo de las variantes alélicas presentes en cada uno de los genes que codifican para los antígenos de interés clínico, utilizando los sistemas de microarreglos o los sistemas basados en partículas marcadas con sondas específicas o sus variantes que permiten un análisis desde el punto de vista inmunohematológico.
Subject(s)
Antigens, Human Platelet , Humans , Genotype , Antigens, Human Platelet/analysis , Antigens, Human Platelet/genetics , Blood Banks , Blood Transfusion , Genotyping Techniques/methodsABSTRACT
Studies have suggested that hepatitis C virus (HCV) may infect not only hepatocytes but may also be carried by platelets. Platelets express more than 20 polymorphic antigenic determinants on their surface, which are called human platelet antigens (HPA). To determine the allele frequency of the HPA-1 to -5 in patients infected with HCV, blood samples were collected from 257 blood donors for the control group and from 191 patients infected with HCV. DNA was isolated and amplified for genes HPA-1 to -4 using PCR Sequence Specific Primers (PCR-SSP) and HPA-5 using PCR-Restriction Fragment Length Polymorphism (PCR-RFLP). The allelic and genotypic frequency of HPA-5a in patients infected with HCV was found to be significantly lower (P < 0.05) than in the controls, and HPA-5b from patients infected with HCV was significantly higher (P < 0.05) than in controls. The increase in HPA-5b allelic frequency in HCV infection may indicate a possible association between HCV infection and HPAs.
Subject(s)
Alleles , Antigens, Human Platelet/genetics , Blood Platelets/immunology , Gene Frequency , Hepacivirus , Hepatitis C , Antigens, Human Platelet/analysis , Blood Donors , Hepatitis C/blood , Hepatitis C/genetics , Hepatitis C/immunology , Hepatitis C/virology , HumansSubject(s)
Humans , Female , Pregnancy , Histocompatibility, Maternal-Fetal/genetics , Thrombocytopenia, Neonatal Alloimmune/diagnosis , Thrombocytopenia, Neonatal Alloimmune/prevention & control , Thrombocytopenia, Neonatal Alloimmune/therapy , Antigens, Human Platelet/analysis , Antigens, Human Platelet/immunology , Pregnancy Complications, Hematologic , Immunoglobulin G/therapeutic use , Isoantibodies/immunology , Neonatal Screening/methods , Platelet TransfusionABSTRACT
Aplication of flow cytofluorometry to blood transfusion: flow citofluorometry has been applied to transfusion medicine for nearly twenty years now. Many of these applications have been for purposes, but several have been suggested for more routine uses. In this summary it is expected to reach of aplication the description of more intervention in the transfusion medicine: detection and quantitation of protein bound to blood cells; detection and quantitation of minor cell population; detection and quantitation of cellular antigens; detection of platelet and WBC antibodies; demostration of platelet activation; demos-tration and quantitation of mocyte interaction with IgG-sensitized RBCs
Subject(s)
Humans , Flow Cytometry/methods , In Vitro Techniques , Immunohistochemistry/standards , Antigens, Human Platelet/analysis , Cell Survival , Erythroid Precursor Cells/classification , Chimera , Flow Cytometry , Erythrocytes/immunology , Fluorescent Dyes , Immunoglobulin G/blood , MosaicismABSTRACT
Aplication of flow cytofluorometry to blood transfusion: flow citofluorometry has been applied to transfusion medicine for nearly twenty years now. Many of these applications have been for purposes, but several have been suggested for more routine uses. In this summary it is expected to reach of aplication the description of more intervention in the transfusion medicine: detection and quantitation of protein bound to blood cells; detection and quantitation of minor cell population; detection and quantitation of cellular antigens; detection of platelet and WBC antibodies; demostration of platelet activation; demos-tration and quantitation of mocyte interaction with IgG-sensitized RBCs (AU)
Subject(s)
Humans , In Vitro Techniques , Flow Cytometry/methods , Immunohistochemistry/standards , Flow Cytometry/statistics & numerical data , Erythrocytes/immunology , Immunoglobulin G/blood , Chimera , Mosaicism , Cell Survival , Fluorescent Dyes/diagnosis , Antigens, Human Platelet/analysis , Erythroid Precursor Cells/classificationABSTRACT
BACKGROUND: Neonatal alloimmune thrombocytopenia (NAIT) is a result of fetomaternal incompatibility. Platelet destruction is caused by a maternal antibody directed against a fetal platelet antigen inherited from the father and lacking on the mother's platelets. The incidence and features of transplacental alloimmunization depend on the frequency of expression of platelet specific antigens; which are highly variable among different populations. AIM: To determine the prevalence and characteristics of transplacental alloimmunization in a large group of pregnant women in Chile. MATERIAL AND METHODS: We studied 3,041 samples obtained during the third trimester of gestation. In all samples, anti platelet antibodies were screened by ELISA with platelet membranes fixed to a microtiter plate. Positive samples were further studied for antigenic specificity with the monoclonal antibody specific immobilization of platelet antigens (MAIPA) test. RESULTS: Anti platelet antibodies were found in 261 samples (8.5%). The MAIPA test identified 6 samples with antibodies directed against major platelet membrane glycoproteins, 2 anti GPIb, 2 anti GPIIb/IIIa and 2 anti GPIa/IIa. In four cases, anti HLA antibodies coexisted. Two cases corresponded to well defined platelet antigen systems: one anti HPA-1a and one anti HPA-5b. No clinical evidence of thrombocytopenia of the newborn was detected in all these cases with anti GP antibodies. CONCLUSIONS: A prevalence of platelet specific antibodies of 0.2% with only one anti HPA-1a was detected. These findings are in contrast with those of other populations but in accordance with the low frequency of the HPA-1 b/b phenotype in the Chilean population. The very low incidence of platelet specific antibodies and the lack of association with clinical thrombocytopenia in the newborn, do not support the recommendation of routine antenatal screening to all women in Chile.