RESUMO
BACKGROUND: In the last few decades, various red blood cell (RBC) freezing techniques have been developed and improved to enable the preservation of erythrocytes for future use in pre-transfusion tests in reference immunohaematology laboratories. However, not all these techniques have been sufficiently evaluated for the preservation of blood group antigens. OBJECTIVES: In this study, we evaluated the antigenic pattern of RBCs preserved by droplet freezing in liquid nitrogen in a blood bank context. METHODS: Blood samples were evaluated for the reactivity of blood group antigens after droplet freezing using the non-permeable cryoprotective agent polyvinylpyrrolidone (PVP) and sucrose-dextrose (S + D) solutions. RESULTS: No qualitative changes were observed in RBC reactivity after freezing and thawing for the antigens Fyb , Leb , C, E, Cw , Lua , Lub , Kpa , Kpb and Dia . However, cryopreservation using PVP resulted in a significant increase in reactivity of Fyb antigen on comparing fresh and frozen samples (P < 0·001). CONCLUSION: The establishment of detailed protocols for cryopreservation of RBCs, which take into account the maintenance of antigenic characteristics, is necessary to increase security in pre-transfusion testing using frozen RBCs.
Assuntos
Bancos de Sangue , Antígenos de Grupos Sanguíneos/imunologia , Preservação de Sangue/métodos , Criopreservação/métodos , Crioprotetores/farmacologia , Eritrócitos/imunologia , Antígenos de Grupos Sanguíneos/metabolismo , Eritrócitos/metabolismo , Feminino , Glucose/farmacologia , Humanos , Masculino , Povidona/farmacologia , Sacarose/farmacologiaAssuntos
Antígenos de Grupos Sanguíneos/genética , Transfusão de Sangue , Técnicas de Genotipagem , Reação em Cadeia da Polimerase em Tempo Real/métodos , Adulto , Alelos , Tipagem e Reações Cruzadas Sanguíneas/métodos , Brasil , DNA/sangue , DNA/genética , Primers do DNA , Feminino , Frequência do Gene , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo de Fragmento de Restrição , Padrões de Referência , Sensibilidade e Especificidade , Adulto JovemRESUMO
OBJECTIVE: Evaluation of the antimicrobial effect of skin disinfection techniques is essential to avoid the transmission of infectious agents during blood transfusion. The aim of this study was to examine the effectiveness of two methods of arm skin disinfection used in blood donors at a Hemotherapy Center in Brazil that represents an important centre for distributing haemocomponents to many cities in the country. METHODS: Two skin disinfection techniques in 50 blood donors were evaluated. For the first arm, 10% povidone-iodine/two-stage technique was used. On the opposite arm, 0.5% chlorhexidine digluconate alcohol solution/one-stage technique was used. The swabs were seeded on three culture media: blood agar, mannitol salt agar and Mac Conkey agar. Automated bacterial classification based on biochemical tests/specific substrates was performed. Donor characteristics were collected using the computerised system of the Hemotherapy Center. RESULTS: We found that microbial reduction was significantly higher for 10% povidone-iodine technique (98.57-98.87%) when compared with 0.5% chlorhexidine technique (94.38-95.06%). The species Leuconostoc mesenteroides and Staphylococcus hominis showed resistance to both disinfection techniques. We did not find statistically significant relationships between donor characteristics and microbial reduction. CONCLUSIONS: Arm skin disinfection with 10% povidone-iodine produced better antimicrobial activity. We must acknowledge that 10% povidone-iodine technique has the limitation of being a two-stage method. However, prevention of adverse events due to bacterial contamination and transfusion reactions should be prioritised. Production of hypoallergenic and stronger antiseptics that allowed a safe one-stage disinfection technique should be encouraged in health systems, not only in Brazil but also around the world.