An easy and efficient strategy for KEL genotyping in a multiethnic population

BACKGROUND: The Kell blood group system expresses high and low frequency antigens with the most important in relation to transfusion including the antithetic KEL1 and KEL2; KEL3 and KEL4; KEL6 and KEL7 antigens. Kell is a clinically relevant system, as it is highly immunogenic and anti-KEL antibodies are associated with hemolytic transfusion reactions and hemolytic disease of the fetus and newborn. Although required in some situations, Kell antigen phenotyping is restricted due to technical limitations. In these cases, molecular approaches maybe a solution. This study proposes three polymerase chain reaction genotyping protocols to analyze the single nucleotide polymorphisms responsible for six Kell antithetic antigens expressed in a Brazilian population. METHODS: DNA was extracted from 800 blood donor samples and three polymerase chain reaction-restriction fragment length polymorphism protocols were used to genotype the KEL*1/KEL*2, KEL*3/KEL*4 and KEL*6/KEL*7 alleles. KEL*3/KEL*4 and KEL*6/KEL*7 genotyping was standardized using the NlaIII and MnlI restriction enzymes and validated using sequencing. KEL*1/KEL*2 genotyping was performed using a previously reported assay. RESULTS: KEL genotyping was successfully implemented in the service; the following distribution of KEL alleles was obtained for a population from southeastern Brazil: KEL*1 (2.2%), KEL*2 (97.8%), KEL*3 (0.69%), KEL*4 (99.31%), KEL*6 (2.69%) and KEL*7 (97.31%). Additionally, two individuals with rare genotypes, KEL*1/KEL*1 and KEL*3/KEL*3, were identified. CONCLUSION: KEL allele genotyping using these methods proved to be reliable and applicable to predict Kell antigen expressions in a Brazilian cohort. This easy and efficient strategy can be employed to provide safer transfusions and to help in rare donor screening.

Magnetic bead technology for viral RNA extraction from serum in blood bank screening

Nucleic acid amplification testing (NAT) was recently recommended by Brazilian legislation and has been implemented at some blood banks in the city of São Paulo, Brazil, in an attempt to reduce blood-born transmission of human immunodeficiency virus (HIV) and hepatitis C virus. OBJECTIVE: Manual magnetic particle-based extraction methods for HIV and HCV viral nucleic acids were evaluated in combination with detection by reverse transcriptase - polymerase chain reaction (RT-PCR) one-step. METHODS: Blood donor samples were collected from January 2010 to September 2010, and minipools of them were submitted to testing. ELISA was used for the analysis of anti-HCV/HIV antibodies. Detection and amplification of viral RNA was performed using real-time PCR. RESULTS: Out of 20.808 samples screened, 53 samples (29 for HCV and 24 for HIV) were confirmed as positive by serological and NAT methods. CONCLUSION: The manual magnetic bead-based extraction in combination with real-time PCR detection can be used to routinely screen blood donation for viremic donors to further increase the safety of blood products.

Bases moleculares do sistema Rh e suas aplicações em obstetrícia e medicina transfusional / The molecular basis of RH system and its applications in obstetrics and transfusion medicine

O sistema Rh é o mais polimórfico e imunogênico de todos os sistemas de grupos sanguíneos. Atualmente mais de 49 antígenos foram identificados sendo cinco principais os antígenos D, C, c, E, e. O conhecimento das bases moleculares do sistema Rh desde a sua primeira clonagem há 17 anos possibilitou o entendimento tanto do mecanismo do fenótipo Rh negativo quanto das variantes dos antígenos RHD e RHCE. As deleções, rearranjos gênicos e as inserções são as principais mutações encontradas. Nos caucasianos, o mecanismo principal do fenótipo Rh negativo é a completa deleção do gene RHD, enquanto nos afrodescendentes é a presença do pseudogene RHDψ e do gene híbrido RHD-CE (4-7)-D. Os autores analisam a estrutura do complexo Rh nas hemácias, as bases moleculares do Sistema Rh, os mecanismos de negatividade RHD, além da Expressão fraca e parcial de D.

The Rh system is the most polymorphic and immunogenic for all blood group systems. Currently more than 49 antigens were identified with five major antigens D, C, c, E, e. Knowledge of the Rh system's molecular basis, since its first cloning 17 years ago, allowed to understand the mechanism of Rh-negative phenotype and the variants of antigens as RHD and RHCE. Deletions, gene rearrangements and insertions are the main mutations. In Caucasians the primary mechanism of Rh-negative phenotype is the complete RHD gene deletion, while in African descendants it is the presence of pseudogene and gene RHDψ hybrid RHD-CE (4-7)-D. The authors analyze the structure of the Rh complex in red cells, molecular basis of the Rh system, mechanisms of Negativity RHD and weak and incomplete expression of RHD.

Associação de CD23 sérico sCD23 e linfoma não Hodgkin em pacientes com AIDS / Association of CD23 serum (sCD23) and non Hodgkin's lymphoma in patients with AIDS

Há evidências de que níveis elevados de sCD23 poderiam ser um marcador sorológico para linfoma não-Hodgkin (LNH) em pacientes com infecção pelo HIV. Realizamos um estudo transversal para medir os níveis séricos de sCD23 em 5 grupos de pacientes: LNH HIV positivos, pacientes com LNH HIV negativos, com AIDS sem LNH, e doadores de sangue HIV positivos e negativos. O nível sérico médio de sCD23 foi .de 7,178,42 g/L nos patients com AIDS e LNH, 4,18 4,99g/L nos patients com AIDS sem LNH, 7,322,09 g/L nos doadores de sangue HIV positivo, 4,701,75 g/L nos doadores de sangue HIV negativo e 15,0220,96 nos pacientes com LNH HIV negativos (P=0,001) / There are evidences that elevated serum levels of sCD23 could be used as a marker to non-Hodgkin’s Lymphoma (NHL) in patients with HIV infection. In order to verify this hipotheses, we carried out a transversal study to measure levels of sCD23 in 5 groups of patients: HIV positive with NHL, HIV negative with NHL, AIDS without NHL, and HIV positive and negative blood donors. The mean levels of sCD23 were 7.178.42g/L in AIDS with NHL, 4.18 4.99g/L in AIDS without NHL, 7.322.09 g/L in the HIV positive blood donors, 4.701.75 g/L in the HIV negative blood donors, and 15.0220.96 in the HIV negative patients with NHL (P=0.001)...

Estudo morfologico de aspirados de medula ossea em pacientes com sindrome de imunodeficiencia adquirida / Morphological study of bone marrow aspirates in patients with AIDS

Entre junho e novembro de 1992, estudamos 42 aspirados de medula ossea de pacientes com Sindrome de Imunodeficiencia Adquirida (SIDA), grupo IV-C (classificacao CDC,1986), para avaliarmos as alteracoes morfologicas, qualitativas e quantitativas, decorrentes desta sindrome. Os criterios clinicos para a realizacao dessas puncoes foram: febre persistente, anemia, leucopenia, trombocitopenia ou uma combinacao dessas anormalidades. Na medula ossea encontramos predominio de hipocelularidade (71,4 por cento), alteracoes mielodisplasicas em todos os casos, eosinofilia (19,0 por cento), plasmocitose (45,2 por cento), linfopenia (21,4 por cento) e macrofagos em numero aumentado (16,7 por cento). No sangue periferico observamos anemia (81,0 por cento), leucopenia (59,5 por cento), neutropenia (42,9 por cento), linfopenia (88,0 por cento), plaquetopenia (33,3 por cento) e pancitopenia (38,0 por cento). As causas dessas anormalidades sao multiplas: infeccoes oportunistas, medicamentos mielosupressores, mecanismos imunologicos e acao direta do HIV sobre celulas progenitoras da medula ossea e celulas maduras do sangue periferico