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. However, levels of these factors were significantly higher in A2O1 donors than in O1O1 donors (VWF:Ag p=0.01; FVIII p=0.04; VWF:RCo p<0.001). Strong correlations were demonstrated between plasma levels of VWF:Ag and FVIII (R=0.77; p=0.001) and between VWF:Ag and VWF:RCo (R=0.75; p=0.001).92236-

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.OBJECTIVE: The aim of this study was to evaluate the efficiency of the flow cytometry platelet immunofluorescence test to screen for immune platelet refractoriness.METHODS: A group of prospective hematologic patients with clinically suspected platelet refractoriness treated in a referral center in Campinas, SP during July 2006 and July 2011 was enrolled in this study. Platelet antibodies were screened using the flow cytometry platelet immunofluorescence test. Anti-human leukocyte antigen antibodies were detected by commercially available methods. The sensitivity, specificity and predictive values of the immunofluorescence test were determined taking into account that the majority of antiplatelet antibodies presented human leukocyte antigen specificity.RESULTS: Seventy-six samples from 32 female and 38 male patients with a median age of 43.5 years (range: 5-84 years) were analyzed. The sensitivity of the test was 86.11% and specificity 75.00% with a positive predictive value of 75.61% and a negative predictive value of 85.71%. The accuracy of the method was 80.26%.CONCLUSION: This study shows that the flow cytometry platelet immunofluorescence test has a high correlation with the anti-human leukocyte antigen antibodies. Despite a few limitations, the method seems to be efficient, fast and feasible as the initial screening for platelet antibody detection and a useful tool to crossmatch platelets for the transfusional support of patients with immune platelet refractoriness.25225

Bartonella Clarridgeiae Bacteremia Detected In An Asymptomatic Blood Donor.

Human exposure to Bartonella clarridgeiae has been reported only on the basis of antibody detection. We report for the first time an asymptomatic human blood donor infected with B. clarridgeiae, as documented by enrichment blood culture, PCR, and DNA sequencing.53352-

Caracterização imunologica eritrocitaria de pacientes portadores de linfomas nao-Hodgkin

Orientador: Carmino Antonio de SouzaDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências MédicasResumo: Estudou-se 77 pacientes adultos portadores de linfoma não Hodgkin (LNH) ao diagnóstico, atendidos no Hospital das Clínicas da Universidade Estadual de Campinas. Classificou-se os LNH histologicamente segundo Kiel. Clinicamente avaliou-se os pacientes através da história e do exame fisico e laboratorialmente pela análise do sangue periférico (hemo grama e contagem de reticulócitos), dosagem de bilirrubinas, urobilinogênio urinário e demais exames necessários ao estadiamento clínico. Estadiou-se os linfomas de acordo com os critérios propostos em Ann Arbor e as leucemias linfocíticas crônicas segundo Rai. Estudou-se os perfis imunohematológicos dos pacientes através dos seguintes testes: determinação de grupo sanguíneo ABO/Rh, teste direto da antiglobulina com soros poliespecífico (anti-IgG, anti-C3b e allti-C3d) e monoespecíficos (anti-IgG, anti-IgM, anti-C3, anti-C3d e anti-C4), pesquisa e identificação de anticorpos séricos pelas técnicas em tubo com polietilenoglicol, meio de baixa força iônica (LISS) e hemácias pré tratadas com enzimas e pela técnica de gel-centrifugação. Os resultados da avaliação imunohematológica dos pacientes portadores de LNH foram: 1. A freqüência de autoanticorpos anti-eritrocitários foi de 29,9% (provável auto anti-I e auto-IgG sem especificidade definida); 2. O quadro de hemólise clínica e laboratorial ocorreu em 1,3% dos pacientes; 3. Houve uma tendência dos linfomas de baixo grau de malignidade serem assocíados à presença de autoanticorpos anti-eritrocitários; 4. Não houve associação entre o tipo imunológico dos LNH (B e T) e do estadiamento clínico dos linfomas com a presença dos autoanticorpos. Conclui-se que a alta incidência de autoanticorpos anti-eritrocitários encontrada em nossa casuística provavelmente esteja relacionada com as alterações imunes próprias dos LNHAbstract: Seventy-seven adult patients with non Hodgkin's lymphoma (NHL) were studied at the time of diagnosis at University Hospital of State University of Campinas from March 1992 to November 1993. Histological subgrouping of NHL was performed according to the Kiel criteria. All patients were characterized by clinical and laboratorial examination, which included cytology of peripheral blood, reticulocyte count, bilirubin, urinary urobilinogen, haptoglobin, exams for staging of lymphoma and immunohematologic evaluation. The patients were staged according to the principIes of the Ann Arbor classification and the cases of chronic lymphocytic leukemia according to Ray clinical staging system. Immunohematology investigation screenings were: determination of blood groups ABO/Rh, direct antiglobulin reaction with polyspecific antiglobulin reagents (anti-IgG, anti-Cb anti-C3d) and monospecific reagents (anti-IgG, anti-IgM, anti-C3, anti-C3d, anti-C4), detection ofblood groups antibodies in serum by indirect antiglobulin test (polyethylene glycol, low ionic strength solution and enzyme-treated ceUs). Whenever an antibody was found on screening, its specificity was determined using a suitable panel of red cells. 1. Our results of the immunohematological evaluation of the patients with NHL showed that: 1-There were 29.87% of the patients 'with autoantibodies against erythrocytes (IgM with probable specificity of auto anti-I and IgG with specificity serologically indlstinguishable), without clinical disorders; 2. The hemolytic anemia occurred in 1.29% of the patients. This value is compatible with the literature; 3. A weak correlation existed between the low grade lymphomas and erythrocyte autoantibodies; 4. No correlation existed between the type immunologic of lymphoma (B e T) and staging of NHL with erythrocyte auto antibodies. We have concluded that probably the high incidence of autoantibodies against erythrocytes would be related to the autoimmune derangements caused by non Hodgkin's lymphomaMestradoMestre em Clinica Medic

Estudo molecular do gene ABO do subgrupo sanguineo A3 e do grupo O de amerindios da tribo Parakanã

Orientador: Sara Teresinha Olalla SaadTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciencias MedicasResumo: O sistema ABO é considerado o mais importante grupo de aloantígenos eritrocitários. Os antígenos A e B são glicoproteínas, cujas estruturas antigênicas dependem da atividade de enzimas, glicosiltransferases, que são produtos do gene ABO. Este gene esta localizado no cromossomo nove e apresenta sete exons, sendo os dois últimos responsáveis pela maior parte da seqüência da proteína codificada. Foram estudados os exons seis e sete de dez doadores do subgrupo Â3 com estudo familiar em três casos e de 71 Ameríndios da tribo Parakanã. Os doadores Â3 foram pré selecionados de acordo com critérios sorológicos e posteriormente foi realizado extração do DNA genômico seguido de amplificação dos dois últimos exons através da reação em cadeia da polimerase. O rastreamento das alterações moleculares nos doadores Â3 foi feito através do polimorfismo de conformação de fita simples de DNA e por seqüenciamento direto. Os índios foram submetidos a amplificação dos exons seis e sete e posterior digestão por enzimas de restrição, com o objetivo de definir a presença .da deleção 261 G e das mutações: G542A, T646A e C771T. Os resultados demonstraram que todos doadores são heterozigotos (A3O) e não , apresentam a mutação G871A previamente descrita. O exon sete é polimórfico em indivíduos A3 e com o estudo familiar foi possível concluir que a deleção 1060C assim como as mutações C467T, T646A e G829A são muito freqüentes neste subgrupo. O grupo sangüíneo O dos índios Parakanãs se caracteriza pela presença da deleção 261 G. O polimorfismo G542A foi demonstrado em 22% dos alelos O e as mutações T646A e C771 T em 65%. Estes resultados são distinto das freqüências descritas em Yanomanis, Araras e Kayapos, o que sugeri provável influencia dos efeitos Gargalo e Fundador neste grupo IndígenaAbstract: The ABO blood group is the most clinically important human alloantigen system in transfusion medicine and includes many variant phenotypes. Phenotypic heterogeneity is due structural differences of the glycosyltransferase gene on chromosome nine, which controls the synthesis of transferase capabie of transferring one immunodominant sugar residue to the substrate H. We have studied the last two coding exons of ABO gene, which occupy 91 % of the soluble form of A1 transferase, from ten unrelated Â3 donors and 71 Parakanã Amerindians. The Â3 subgroup was defined according to immunohematological evaluation. Exons six and seven of the ABO gene were amplified and submitted to single strand conformation polymorphism and direct sequencing. The Amerindians were studied by PCR-RFLP for determination the 261 G deletion, the T646A and C771T mutations described in O 1variant and the G542A substitution. Ali Â3 donors have showed heterozygosity for the 261 G deletion (Â30) and have not presented the G871A mutation, previously described in this blood subgroup. The exon seven were heterogeneous at the molecularl~vel and with family studies were possible to conclude that the 1 D6DC deletionand the C467T, T646A and G829A mutations were frequently in this subgroup Ali Amerindians studied were 01 as described in other Indians group. Otherwise, the Parakanã presented lower frequencies of the G542A (22%), T646A and C771T mutation (65%) than other tribes. We concluded that the G542A and probably the O 1v allele are not distributed homogeneously among ali Amazonian Amerindians. The distinct result found in Parakanã Indians suggests a consequence of random genetic driftDoutoradoDoutor em Clínica Médic

Electrical properties of the red blood cell membrane and immunohematological investigation

Hemagglutination is widely used in transfusion medicine and depends on several factors including antigens, antibodies, electrical properties of red blood cells and the environment of the reaction. Intermolecular forces are involved in agglutination with cell clumping occurring when the aggregation force is greater than the force of repulsion. Repulsive force is generated by negative charges on the red blood cell surface that occur due to the presence of the carboxyl group of sialic acids in the cell membrane; these charges create a repulsive electric zeta potential between cells. In transfusion services, specific solutions are used to improve hemagglutination, including enzymes that reduce the negative charge of red blood cells, LISS which improves the binding of antibodies to antigens and macromolecules that decrease the distance between erythrocytes. The specificity and sensitivity of immunohematological reactions depend directly on the appropriate use of these solutions. Knowledge of the electrical properties of red blood cells and of the action of enhancement solutions can contribute to the immunohematology practice in transfusion services

Electrical Properties Of The Red Blood Cell Membrane And Immunohematological Investigation.

Hemagglutination is widely used in transfusion medicine and depends on several factors including antigens, antibodies, electrical properties of red blood cells and the environment of the reaction. Intermolecular forces are involved in agglutination with cell clumping occurring when the aggregation force is greater than the force of repulsion. Repulsive force is generated by negative charges on the red blood cell surface that occur due to the presence of the carboxyl group of sialic acids in the cell membrane; these charges create a repulsive electric zeta potential between cells. In transfusion services, specific solutions are used to improve hemagglutination, including enzymes that reduce the negative charge of red blood cells, LISS which improves the binding of antibodies to antigens and macromolecules that decrease the distance between erythrocytes. The specificity and sensitivity of immunohematological reactions depend directly on the appropriate use of these solutions. Knowledge of the electrical properties of red blood cells and of the action of enhancement solutions can contribute to the immunohematology practice in transfusion services.33297-30