RESUMO
Severe anaphylactic or allergic reactions may occur during blood transfusion to patients who are IgA-deficient and have anti-IgA in their blood, particularly those with class-specific antibodies. These patients are a particular challenge to the hospital transfusion service when large volumes of blood components are required for transfusion support, as in liver transplantation. We have successfully provided blood components for 3 such patients undergoing liver transplantation. Red cells were washed manually or by automated technique. Platelets were washed manually. All plasma was from IgA-deficient donors. One patient's entire plasma requirements were supplied by autologous plasmapheresis. Serial determinations of IgA levels and anti-IgA titers in 1 patient demonstrated an abrupt fall in anti-IgA with the appearance of barely detectable amounts of IgA during the surgery. IgA-containing plasma cells were demonstrated in the biopsies of liver homografts of 2 patients following transplantation. IgA deficiency with anti-IgA can be successfully managed during liver transplantation with advance planning.
Assuntos
Transfusão de Sangue , Deficiência de IgA/terapia , Transplante de Fígado , Adolescente , Adulto , Autoanticorpos , Transfusão de Sangue/métodos , Eritrócitos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Plasmaferese , Reação TransfusionalRESUMO
A compulsory programme of proficiency testing in immunohaematology has been conducted for the last 4 years. The collection, processing and analysis of testing data reported by participating laboratories depends on a computer-based system, which allows the generation of reports for participants and working documents essential to the functioning of a committee which supervises the operation of the programme. The options open to the committee in coping with laboratories with poor performance are summarized.
Assuntos
Antígenos de Grupos Sanguíneos , Laboratórios/normas , Padrões de Referência , Sistema ABO de Grupos Sanguíneos , Anticorpos , Computadores , Teste de Coombs , Coleta de Dados , Erros de Diagnóstico , Humanos , Sistema do Grupo Sanguíneo Rh-HrRESUMO
An analysis of the results of a compulsory proficiency testing programme in immunohaematology is presented. Error rates have been calculated for the determination of ABO and Rh(D) groups, the direct antiglobulin test and antibody detection according to defined criteria. The introduction of proficiency testing has been associated with alterations in error rates for some determinations. An educational programme introduced for laboratories with poor performance has proved effective in improving their results in the proficiency testing programme.
Assuntos
Antígenos de Grupos Sanguíneos , Laboratórios/normas , Padrões de Referência , Sistema ABO de Grupos Sanguíneos , Anticorpos , Tipagem e Reações Cruzadas Sanguíneas , Coleta de Dados , Humanos , Sistema do Grupo Sanguíneo Rh-HrRESUMO
Since April 1975 the proficiency of laboratories in Ontario that perform immunohematology tests has been assessed. While the majority of test samples have required only ABO and Rh(D) typing, others have posed problems. The error rate in uncomplicated ABO typing was 1.3/1,000 in 17,479 tests and that in straightforward Rh(D) grouping, 6.6/1,000 in 17,757 tests. False-negative (36/1,000) and false-positive (1.4/1,000) direct antiglobulin tests occurred. Errors in detection of strong alloantibodies (e.g., anti-D) were 19.7, 10.2 and 5.1/1,000 in three test samples. A2B or A2 cells with anti-A1 in serum were sent out in two surveys; error rates in ABO interpretation were 189 and 52/1,000, respectively. Laboratories also experienced difficulty in interpreting the Rh(D) type of cells with positive antiglobulin tests. These surveys have had several effects: (1) laboratories with poor performance have been identified, (2) patterns of practice have been influenced, (3) areas of ignorance have been identified, and (4) a stimulus has been provided for continuing education in immunohematology.
Assuntos
Técnicas Imunológicas/normas , Laboratórios/normas , Sistema ABO de Grupos Sanguíneos , Tipagem e Reações Cruzadas Sanguíneas , Teste de Coombs , Reações Falso-Negativas , Reações Falso-Positivas , Humanos , Isoanticorpos/análise , Ontário , Sistema do Grupo Sanguíneo Rh-HrRESUMO
Investigation of the serum of three patients with positive antibody detection tests demonstrated the cause in each to be an antibody against chloramphenicol, a bacteriostatic agent used in commercial red blood cell reagents. Washing of these red cells prior to use prevented agglutination. All three examples of anti-chloramphenicol antibody were IgM and were in low titer when tested at room temperature and 37 C in saline. Two of the antibodies bound complement. The possibility of an antibody to an ingredient of the commercial preservative solution should be considered if problems are encountered in tests with unwashed commercial red blood cell reagents.
