Immunohematology

The aim of this research was verify the frequency of erythrocyte antigen K1 in the population of donors who had their blood phenotyped at Regional Blood Center of Passo Fundo (RS). This descriptive study of documental approach was conduct through retrospective evaluation of record spreadsheets for all donors phenotyped during the period of July 2010 to June 2015. An absolute verification was done, comparing the number of donors without the expressed antigen KELL and the number of donors who had this antigen on the erythrocyte membrane. From 1,163 phenotyped donors, 80 (7%) showed antigen expression in the erythrocyte membrane, being lower number than reported in the literature. Despite the percentage found for the K1 expression be lower than is described by other authors, the antigen must be identified because its immunogenicity has great clinical relevance and may result in transfusion complications. RESUMO: O objetivo desta pesquisa foi verificar a frequência do antígeno eritrocitário K1 na população de doadores que tiveram seu sangue fenotipado no Hemocentro Regional de Passo Fundo (RS). Este estudo descritivo de abordagem documental foi realizado por meio de avaliação retrospectiva de planilhas de registro de todos doadores fenotipados durante o período de julho de 2010 a junho de 2015. Na análise, foi realizada uma verificação absoluta comparando o número de doadores sem o antígeno expressado KELL e o número de doadores que apresentavam esse antígeno na membrana eritrocitária. Dos 1.163 doadores fenotipados, 80 (7%) apresentaram expressão antigênica na membrana eritrocitária, sendo menor que o relatado na lite-ratura. Apesar da porcentagem encontrada para a expressão de K1 ser menor do que a descrita por outros autores, o antígeno deve ser identificado porque sua imunogenicidade tem grande relevância clínica e pode resultar em complicações transfusionais. Palavras-chave: antígenos de grupos sanguíneos; sistema do grupo sanguíneo de Kell; reação transfusio-nal; transfusão de sangue.

Objective: To determines the prevalence of red cell antibodies in incompatible cross match cases. Study design: It was a cross-section descriptive study. Method: ABO (forward and reverse) and Rh D grouping of donor and recipient's and serological cross matches are performed using Indirect Antiglobulin test. All incompatible cross match cases are further evaluated in immunohematology. The samples of recipient of incompatible cross match cases are subjected to DAT. Auto control red cell antibody screening and red cell antibody identification panels as required to save the discrepancies in individual cases. Result: Total 37 incompatible cross matches cases performed during the study period. ABO discrepancy was the cause of incompatible cross match in 6 of these cases. The cause of incompatible was autoantibodies in 8, compatible after fresh sample were 9, auto immune hemolytic anemia were 8, and alloantibodies in 14 cases. Conclusion: The IAT cross match is an essential part of compatibility testing before blood transfusion. Antibody screening is not routinely performed on donors or recipients. The cross match incompatible is usually the first indicator of presence of allo/auto antibodies in the recipient serum. The prevalence of 0.105 % of incompatible cross match cases in this study stress the need of IAT cross match before red cell transfusion to avoid the life threating complications. It also signifies the importance of further evaluation of cross match incompatible cases to rule out the presence of significant antibodies.