Comparative Analysis of Clinical Samples Showing Weak Serum Reaction on AutoVue System Causing ABO Blood Typing Discrepancies

BACKGROUND: ABO blood typing in pre-transfusion testing is a major component of the high workload in blood banks that therefore requires automation. We often experienced discrepant results from an automated system, especially weak serum reactions. We evaluated the discrepant results by the reference manual method to confirm ABO blood typing. METHODS: In total, 13,113 blood samples were tested with the AutoVue system; all samples were run in parallel with the reference manual method according to the laboratory protocol. RESULTS: The AutoVue system confirmed ABO blood typing of 12,816 samples (97.7%), and these results were concordant with those of the manual method. The remaining 297 samples (2.3%) showed discrepant results in the AutoVue system and were confirmed by the manual method. The discrepant results involved weak serum reactions (<2+ reaction grade), extra serum reactions, samples from patients who had received stem cell transplants, ABO subgroups, and specific system error messages. Among the 98 samples showing ≤1+ reaction grade in the AutoVue system, 70 samples (71.4%) showed a normal serum reaction (≥2+ reaction grade) with the manual method, and 28 samples (28.6%) showed weak serum reaction in both methods. CONCLUSIONS: ABO blood tying of 97.7% samples could be confirmed by the AutoVue system and a small proportion (2.3%) needed to be re-evaluated by the manual method. Samples with a 2+ reaction grade in serum typing do not need to be evaluated manually, while those with ≤1+ reaction grade do.

ABO-incompatible living-donor pediatric kidney transplantation in Japan

The Japanese ABO-Incompatible Transplantation Committee officially collected and analyzed data on pediatric ABO-incompatible living-donor kidney transplantation in July 2012. The age of a child was defined as <16 years, and 89 children who had undergone ABO-incompatible living-donor kidney transplantation from 1989 to 2011 were entered in a registry. These data were presented as the Japanese registry of pediatric ABO-incompatible living-donor kidney transplantation at the regional meetings of the International Pediatric Transplantation Association (IPTA) in Nagoya in September 2012 and in Sao Paulo in November 2012.

Economic and Workflow Analysis of a Blood Bank Automated System

BACKGROUND: This study compared the estimated costs and times required for ABO/Rh(D) typing and unexpected antibody screening using an automated system and manual methods. METHODS: The total cost included direct and labor costs. Labor costs were calculated on the basis of the average operator salaries and unit values (minutes), which was the hands-on time required to test one sample. To estimate unit values, workflows were recorded on video, and the time required for each process was analyzed separately. RESULTS: The unit values of ABO/Rh(D) typing using the manual method were 5.65 and 8.1 min during regular and unsocial working hours, respectively. The unit value was less than 3.5 min when several samples were tested simultaneously. The unit value for unexpected antibody screening was 2.6 min. The unit values using the automated method for ABO/Rh(D) typing, unexpected antibody screening, and both simultaneously were all 1.5 min. The total cost of ABO/Rh(D) typing of only one sample using the automated analyzer was lower than that of testing only one sample using the manual technique but higher than that of testing several samples simultaneously. The total cost of unexpected antibody screening using an automated analyzer was less than that using the manual method. CONCLUSIONS: ABO/Rh(D) typing using an automated analyzer incurs a lower unit value and cost than that using the manual technique when only one sample is tested at a time. Unexpected antibody screening using an automated analyzer always incurs a lower unit value and cost than that using the manual technique.

Murine monoclonal anti-H as typing reagent.

BACKGROUND & OBJECTIVE: The antigen H present on the surface of red cells in varying concentration, is maximum in O group red cells, but absent in Bombay phenotype individuals. This differentiation is generally detected by seed extracts of Ulex europaeus. The titre of such an extract is usually low and is subjected to batch variation. Hence, we carried out this study to raise potent murine monoclonal antibody against H antigen. METHODS: Spleen cells of female BALB/c mice immunized with O group red cells were fused in presence of polyethylene glycol (PEG) 1500 with a mouse myeloma cell line Sp2/0 Ag14 in hypoxanthine aminopterine thymidine (HAT) selective medium and incubated at 37 degrees, 5 per cent CO(2) and 95 per cent humidity for a week. RESULTS: The culture supernatants showing anti-H activity, were further subcloned and two clones 3E8A10 and 3E8A11 generated which showed a good potency, avidity and specificity. INTERPRETATION & CONCLUSION: The anti-H clones thus produced indigenously provided a potent reagent in distinguishing normal O group from Bombay phenotype individuals. The unlimited availability makes this reagent cost-effective to ensure a constant supply of hybrid clones with the similar specificities.

Evaluation of Two Automated Instruments for Pre-transfusion Testing: AutoVue Innova and Techno TwinStation / 대한진단검사의학회지

BACKGROUND: Despite the advances in total laboratory automation, a considerable amount of work in blood banks is still done using outdated manual methods. Some automated pre-transfusion testing instruments have recently been developed. Of these, we evaluated and compared the AutoVue Innova (Ortho, USA) and the Techno TwinStation (DiaMed AG, Switzerland). METHODS: Forward and reverse ABO/Rh typing and unexpected antibody screening and identification tests were performed on 4,628 samples using the manual method and the two automated instruments. Two different anticoagulants (EDTA and citrate) were compared in ABO/Rh typing and unexpected antibody screening tests. Titrating studies were conducted on the following 7 dilutions using 5 samples of irregular antibodies with anti-E, anti-E & -c, anti-D, and anti-Le(a) with anti-Fy(a): 1:2, 1:4, 1:8, 1:16, 1:32, 1:64, and 1:128. The test throughput per hour, the time required to perform 1 and 100 tests, and a simulation test for total events occurring in 1 day were also measured. RESULTS: No erroneous results were reported between the two instruments and the manual method. Discrepancies observed in 10 cases (0.4%) of ABO/Rh typing were of higher intensity with AutoVue Innova than with the manual method. AutoVue Innova exhibited the highest sensitivity in the titrating study and throughput performance compared with the manual method and the Techno TwinStation. Especially in the throughput and time required to complete 100 antibody screening tests, AutoVue Innova had a 3.3- and 3.5-fold higher performance, respectively, than Techno TwinStation. CONCLUSIONS: Because both of the two fully automated instruments (AutoVue Innova and Techno TwinStation) had high levels of accuracy and performance, it is expected that use of fully automated instruments will reduce human labor, turnaround time, and operator error in the blood bank.

Freqüência de hemolisinas anti-A e anti-B em doadores de sangue do Hemocentro de Botucatu / Anti-A and anti-B hemolysin frequencies in blood donors from the Hemotherapy Center of Unesp, Botucatu

O Sistema ABO foi descoberto em 1900 e permanece até hoje como sendo o sistema mais importante dentro da prática transfusional. A transfusão ABO incorreta pode resultar na morte do paciente, com uma reação hemolítica intravascular, seguida de alterações imunológicas e bioquímicas. Os anticorpos ABO estão presentes nos soros dos indivíduos, dirigidos contra os antígenos A e/ou B ausentes nas hemácias. Embora as transfusões com pequenas quantias de plasmas incompatíveis sejam geralmente consideradas uma prática segura, alguns casos de reações hemolíticas por plasma incompatível são encontrados na literatura. Tendo em vista a pequena quantidade de estudos sobre as hemolisinas anti-A e anti-B e a importância desses anticorpos na prática transfusional, objetivamos neste trabalho verificar a freqüência dessas hemolisinas em doadores de sangue do Hemocentro da Unesp de Botucatu. Foram analisadas 600 amostras de soros de doadores do grupo "O" para presença ou ausência das hemolisinas anti-A e anti-B. Desses doadores, 77 (12,8 por cento) foram classificados como perigosos por apresentarem em seu soro altos títulos de hemolisinas e 523 (87,2 por cento) como não perigosos por apresentarem baixos títulos. No grupo dos doadores perigosos, 45 (58,4 por cento) foram reativos para hemolisina anti-A, 11 (14,2 por cento) reativos para hemolisina anti-B e 21 (27,2 por cento) reativos para ambas. O título de aglutininas superior a 1/100 já considera o doador "O" como perigoso. Assim, o teste realizado em nossa rotina é suficiente para detecção de altos títulos fazendo com que os pacientes dos outros grupos sangüíneos não corram o risco de reação transfusional se necessitarem de transfusão sangüínea não-isogrupo.

El primer hallazgo de un subgrupo débil de B(Bm) en Costa Rica / The first feeble subgroup of B(Bm) in Costa Rica

En un análisis de rutina, efectuado en el Banco de Sangre del Instituto Materno Infantil Dr. Adolfo Carit Eva, se encotró un caso de un subgrupo débil de B en una paciente costarricense de 48 años de edad. Las pruebas realizadas en su eritrocitos, suero y saliva nos indican la ausencia del antígeno B en sus eritrocitos, la ausencia del anticuerpo homólogo en su suero y la presencia de sustancia B y H en su saliva, lo que nos permite clasificar a este subrupo con un Bm

Incidencia de la deficiencia de sustancia H en los eritrocitos de los grupos A y AB / Incidence of H deficiency in erythrocytes of A and AB groups

Se investigó la deficiencia de sustancia precursora H de los grupos sanguíneos A y AB, en 547 donantes de sangre (397 blancos y 150 negros). Se estimó el rango de puntuación de la aglutinación de un grupo control de 40 donantes, correspondientes a los grupos sanguíneos A1, A2, A1B y A2B. En el suero de los donantes deficientes de H se determinó la presencia de anticuerpos eritrocitarios. En los donantes blancos el grupo A, predominó sobre el A2, de forma contraria ocurrió en los negros. En los 2 grupos raciales estudiados, tanto para el grupo A como el AB, se encontraron variantes deficientes de H codificadas por los genes A1 y A2. En toda la muestra se halló una mayor frecuencia de variantes deficientes A2B, especialmente en los negros. No se observaron anticuerpos anti-H en el suero de las variantes

Niveles de factor VIII coagulante en donantes de sangre según el tipo sanguíneo ABO / Level of factor VIII coagulant in blood donors according to ABO blood type

Se estudió la actividad del factor VIII coagulante en individuos sanos clasificados según los grupos sanguíneos, con el fin de obtener valores normales para contribuir a un mejor diagnóstico de laboratorio en pacientes con problemas hemorragíparos. Se estudiaron 128 dadores de sangre, cuyas edades variaron entre 18 y 59 años, seleccionados según las normas de los Bancos de Sangre. Se determinó el Factor VIII coagulante (FVIII:C), usando la técnica de Biggs y col. en una etapa y el grupo sanguíneo ABO por métodos convencionales. Los valores de referencia del FVIII:C fueron de 35 por ciento para los individuos tipo O y de 50 por ciento para los sujetos tipo A, B y AB. estos valores permitirán mejorar el diagnóstico de laboratorio y el tratamiento con crioprecipitados en pacientes con enfermedades hemorragíparas, como hemofilia clásica y la enfermedad de Von Willebrand

Diagnóstico de la incompatibilidad ABO con base en estudio inmunohematológico / Diagnostic of the incompatibility ABO with base in inmunohematologi study

Se estudiaron 492 casos de niños con incompatibilidad inmunológica materno infantil por el sistema ABO. A todas las muestras se les efectuó la prueba directa e indirecta de Coombs; así como un eluido. En ambos grupos, los resultados positivos más altos fueron para los eluidos, con 319 casos en comparación con 194 casos de Coombs indirectos y 63 de Coombs directos. Consecuentemente los resultados negativos más frecuentes fueron para los Coombs directos con 429 casos a diferencia de 173 casos en eluidos y 298 en suero. Los estudios en los eluidos demostraron que el anticuerpo más frecuente fue el A,B, y 21 de anti B; así como 24 casos en los que el anticuerpo presente no correspondió a la incompatibilidad que existía entre la madre y el niño. Se concluye que es necesario hacer el eluido cuando el estudio en suero es negativo y hay sospecha de enfermedad hemolítica por ABO.

Frecuencia de los grupos sanguíneos ABO y factor Rho(D) en la población de origen aymara de la primera región / Frequency of ABO and Rhഠ D blood groups in the aymara stock population in the first region

La frecuencia de los grupos sanguíneos ABO y el factor Rhഠ presentan una gran variabilidad en los grupos étnicos a nivel mundial. Se estudiaron mil nueve individuos de ambos sexos procedentes del altiplano de la Primera Región, de los cuales, seiscientos noventa y seis son de padres aymara y trescientos trece mestizos, con uno de los progenitores de origen aymara. Se tomó una muestra de sangre a cada individuo, por punción venosa y para la determinación de antígenos ABO y factor Rhഠ, se utilizaron el método en tubo y sueros clasificadores, además para el sistema ABO, se usó el método inverso. Los resultados obtenidos en el grupo aymara fueron: Grupo 0 Rhഠ + :95 por ciento. Grupo 0 Rhഠ (-) Du (-): 0,1 por ciento. Grupo A Rhഠ + 3,6 por ciento y Grupo B Rhഠ + : 1,3 por ciento. En el grupo mestizo, en estudio, los resultados fueron: Grupo 0 Rhഠ + :68 por ciento. Grupo A Rhഠ + :20,1 por ciento. Grupo B Rhഠ + : 11 por ciento, Grupo AB Rhഠ + : 0,6 por ciento y Grupo AB Rhഠ (-) Du (-): 0,3 por ciento. De los resultados obtenidos se concluye que en la población aymara el grupo 0 Rhഠ + presenta una elevada frecuencia.