Irregular Antibody Screening Using a Microdroplet Platform.

The screening procedure for antibodies is considered the most tedious among the three pretransfusion operations, i.e., ABO and Rhesus (Rh) typing, irregular antibody screening/identification, and crossmatching tests. The commonly used screening method for irregular antibodies in clinics at present is a manual polybrene test (MP). The MP test involves numerous reagent replacement and centrifuge procedures, and the sample volume is expected to be relatively less. Herein, screening red blood cells (RBCs) and serum irregular antibodies are encapsulated in microdroplets with a diameter of ~300 µm for a hemagglutination reaction. Owing to the advantage of spatial limitation in microdroplets, screening RBCs and irregular antibodies can be directly agglutinated, thereby eliminating the need for centrifugation and the addition of reagents to promote agglutination, as required by the MP method. Furthermore, the results for a large number of repeated tests can be concurrently obtained, further simplifying the steps of irregular antibody screening and increasing accuracy. Eight irregular antibodies are screened using the proposed platform, and the results are consistent with the MP method. Moreover, the volume of blood samples and antibodies can be reduced to 10 µL and 5 µL, respectively, which is ten times less than that using the MP method.

Red blood cell alloantibodies in paediatric transfusion in sub-Saharan Africa: A new cohort and literature review.

Blood transfusion support predisposes transfused children to the risk of erythrocyte alloimmunization in Sub-Saharan Africa. A cohort of 100 children receiving one to five blood transfusions were recruited for screening and identification of irregular antibodies using gel filtration technique. The mean age was 8 years and the sex-ratio at 1.2. The retrieved pathologies were: major sickle cell anaemia (46%), severe malaria (20%), haemolytic anaemia (4%), severe acute malnutrition (6%), acute gastroenteritis (5%), chronic infectious syndrome (12%) and congenital heart disease (7%). The children presented with haemoglobin levels ≤6 g/dl, and 16% of them presented positive irregular antibodies directed against the Rhesus (30.76%) and Kell (69.24%) blood group systems. A literature review shows that irregular antibody screenings vary from 17% to 30% of transfused paediatric patients in Sub-Saharan Africa. These alloantibodies are in particular directed against the Rhesus, Kell, Duffy, Kidd and MNS blood group and generally found in sickle cell disease and malaria. This study highlights the urgent need of extended red blood cell phenotyping including typing for C/c, E/e, K/k, and Fya/Fyb, and if possible Jka/Jkb, M/N, and S/s for children before transfusion in Sub-Saharan Africa.

Hemolytic disease of the fetus and newborn caused by irregular antibody: A mortality case report and case series during the past 15 years in NCKUH.

OBJECTIVE: Hemolytic disease of the fetus and newborn (HDFN) caused by irregular antibodies is a rare, but possibly life-threatening condition. We report a case of severe intrauterine hemolysis caused by anti-E alloimmunization, and review 16 cases in the past 15 years of our hospital. CASE REPORT: A woman with gestational age 28 weeks and 5 days, received emergent Cesarean section because of fetal distress. The baby was expired at the next day after delivery and the comprehensive study showed severe anemia and alloimmunization related hemolysis caused by anti-E due to high antibody titer (1: 4096). CONCLUSION: Anti-E antibody is one of the most common non-Rhesus D antibodies in the pathogenesis of HDFN, but rarely leads to severe hemolysis. However, our case has the highest reported anti-E titer in HDFN and is the first case of mortality during the past 15 years in NCKUH.

The processing of blood with irregular antibodies and its clinical application / 中国输血杂志

【Objective】 Toexplore the viability of preparing washed RBCs ordeglycerolized RBCs(referred as frozen RBCs)from blood containing irregular antibodies, so as to provide references for formulating processing procedures of blood containing irregular antibodiestosave blood resources and reduce blood wastage. 【Methods】 Once irregular antibodies were yielded, their type and titerwere determined.The plasma was discarded, and the suspended RBCs were prepared and processed according to the standardized washing scheme.The processing effect of blood with different titers and types of antibodies was observed, and theirfurther clinical application was followed up. 【Results】 From May 2017 to July 2019, a total of 45 blood samples containing irregular antibodies were screened in our center. The overall qualified rate reached 91.1% after processing. 100%(25/25) was qualified in IgM, and 80.0%(16/20)in IgG.4samples, initially noncom for mingdue to IgG-Dwith titerranged8~16, met the requirements after one or two additional washing processes. Among them, 23 cases were issued and appliedin clinicaland noadeverse reactions to blood transfusionoccurred. 【Conclusion】 After appropriate processing, blood containing irregular antibody can be applied to the clinical to save blood resources. When the irregular antibody is IgG-D and the titer is high, the washing times should be increased, and only when there is no residual antibodycan the samples be issued to the clinical.

Effects of cooperative blood transfusion and homologous blood transfusion on the production of red blood cell irregular antibodies in obstetric patients.

Effects of cooperative blood transfusion and homologous blood transfusion on the production of red blood cell irregular antibodies in obstetric patients were investigated. A total of 300 obstetric patients who underwent blood transfusion in the Maternity and Child Health Care of Zaozhuang from February 2016 to February 2018 were enrolled. There were 150 obstetric patients receiving the same type of transfusion who were included in the control group. Due to special circumstances the remaining 150 obstetric patients with ABO and Hr with cooperative blood transfusion were included in the research group. The positive detection rate of blood cell irregular antibody, the effectiveness of blood transfusion and the incidence of adverse transfusion reaction were observed in the two groups after the comparison of blood transfusion of both groups. The total positive detection rate of erythrocyte irregular antibody in the research and control groups was not statistically significant (P>0.05). There were no significant differences in the red blood cell counts, hemoglobin concentration, hematocrit and platelet count between the research and control groups after infusion (P>0.05). Comparing all the groups, the red blood cell counts, hemoglobin concentration, hematocrit and platelet count after infusion in both the research and control groups were significantly higher than before the infusion, and differences were statistically significant (P<0.001). There was no significant difference in the incidence of adverse reactions between the two groups (P>0.05). The effect of blood transfusion and homologous blood transfusion on the positive detection rate of red blood cell irregular antibody in obstetric patients, the efficiency of blood transfusion and the incidence of adverse transfusion reactions are similar, and all have high clinical application value.

Prevalencia de anticuerpos irregulares en donantes en un banco de sangre de Antioquia, 2016-2018 / Prevalence of irregular antibodies in donors of the blood bank in Antioquia, 2016-2018

Resumen Introducción: la aloinmunización se presenta entre 1,0-1,5 % de las personas expuestas a un antígeno externo o durante el embarazo, un trasplante o una transfusión. En los bancos de sangre se realiza la tamización de anticuerpos irregulares, diferentes a los del sistema ABO. Objetivo: estimar la prevalencia de anticuerpos irregulares en donantes de un banco de sangre de Medellín entre 2016 y 2018. Métodos: estudio transversal en 25 391 donantes. Se realizó control de sesgos de selección e información mediante aplicación de técnicas con excelente validez y control de calidad interno y externo, y detección mediante ID-card Liss/coombs en seis microtubos con anti-IgG y anti-C3d. El análisis se basó en medidas de resumen, frecuencias, chi cuadrado y prueba exacta de Fisher. Resultados: la edad promedio fue 34 años. La prevalencia de anticuerpos irregulares fue 0,30 %, siendo mayor anti-D con 0,071 %. No se hallaron diferencias según el sexo y el grupo etario; anti-D fue más frecuente en mujeres y donantes entre 31 y 40 años. Conclusión: se halló una alta prevalencia de anti-D y antiKell, que presentan gran importancia clínica después de los anticuerpos del sistema ABO. Esto evidencia la necesidad de esta prueba para reducir las reacciones post-transfusionales.

Abstract Introduction: Alloimmunization occurs between 1.0-1.5 % of people exposed to an external antigen or during pregnancy, a transplant or transfusion. In the blood banks, the screening of irregular antibodies different from those of the ABO system is performed. Objective: To estimate the prevalence of irregular antibodies in donors of a blood in Medellin 2016-2018. Methods: Cross-sectional study in 25 391 donors. Control of selection and information bias was carried out by applying techniques with excellent validity and internal and external quality control, and detection by ID-card Liss / coombs in six microtubes with anti-IgG and anti-C3d. The analysis was based on measures of summary, frequencies, chi-square and Fisher's exact. Results: The average age was 34 years. The prevalence of irregular antibodies was 0.30%, being higher anti-D with 0.071%. No statistical differences were found according to sex and age group; Anti-D was more frequent in women and donors aged 31-40 years. Conclusion: A high prevalence of Anti-D and Anti-Kell was found, which are of great clinical importance after the antibodies of the ABO system. This demonstrates the need for this test to reduce post-transfusion reactions.

Preliminary investigation and analysis of irregular antibodies of blood group before patients′transfusion / 医学研究生学报

Objective Irregular antibody screening and identification are very important to reduce hemolytic reaction.The dis-tribution of irregular antibodies of blood group was analyzed in patients, to provide evidence for using Micro column gel test to detect and identify irregular antibodies transfusion safety. Methods Micro column gel anti-globulin technique was used to screen the irregular an-tibodies and cross-matching in 29770 patients.If the serum had irregular antibodies, the spectrum cells were used to identify the specific-ity of irregular antibodies. Results Among 29 770 patients, 120 cases had irregular antibodies of blood group.The positive rate was 0.4%.The irregular antibodies include Rh system(n=67),MNS system (n=7), Lewis system(n=5),cases of Kidd system(n=3) and undefined specified antibodies(n=38).Among the 120 antibody-positive patients, 70 were female patients and 50 were male patients. Further study showed that the pregnancy history was to the main factor causing irregular antibodies in women (46 positive cases among 70 female patients) . Conclusion The study showed that some patients had irregular antibodies of blood group, especially female patients with pregnancy history.These results suggested that irregular antibody screening and cross-matching by micro column gel method in pa-tients before transfusion had great significance for ensuring the blood transfusion safety.

High Estradiol Levels During Postmenopause - Pitfalls in Laboratory Analysis.

A 54-year-old woman was admitted with a result of high serum estradiol levels (> 4300 pg/ml) and typical postmenopausal symptoms. She had a history of an adnexectomy (normal histopathology) due to the elevated estradiol levels. After surgery, estradiol levels were as high as before. Analyzing the anti-mullerian hormone (AMH), inhibin B, DHEA-S and estrone, typical postmenopausal levels were found. Serum estradiol levels were controlled several times with rabbit-derived polyclonal as well as monoclonal antibodies to optimize the selectivity of the test system. Secondary, a radioimmunoassay was performed to exclude interferences of the detection system where lower, but still elevated estradiol levels (186 pg/ml) were found. Hypothesizing that our patient underwent a cross reaction with irregular antibodies, a control was done using sheep-derived antibodies, which proved a postmenopausal hormone level (estradiol level < 5 pg/ml). This result was confirmed using a fluorescence enzyme immunoassay (FEIA) revealing high levels of irregular antibodies (> 200 mg/l; reference < 30 mg/l). This case depicts the pitfalls of estradiol measurement detecting false elevated estradiol levels in a postmenopausal woman.

Suspected anemia caused by maternal anti-Jra antibodies: a case report.

Most cases of hemolytic disease of the newborn associated with anti-Jra are mild. However, rare cases of hydrops fetalis and severe anemia have been reported. We treated a neonate with anemia who was born with maternal anti-Jra, which were detected in the umbilical cord plasma. The Jra antigens in the neonate core blood red blood cells (RBCs) exhibited extremely weak reactivity to PEG-IAT, an anti-Jra reagent. However, upon re-examination of Jra antigen using PEG-IAT at 3 months postpartum, positivity was observed. Thereafter, upon performing PCR-SSP analysis of blood relatives targeting ABCG2 at positions 376 and 421, we found that the mother was Jr(a-) with 376 T homozygosity, whereas the father was Jr(a+) with 376 C homozygosity and a carrier of a 421 C > A mutation. The first sibling, like the propositus, was Jr(a+), exhibiting 376 CT heterozygosity. However, the first sibling carried a 421 C > A mutation, whereas the propositus had no mutation at position 421. Setting the normal Jra (a+) type (376 C, 421 C) to 100 %, we identified the amount of Jra in RBC using FCM to be 82 % in the father, 31 % in the first sibling, and 69 % in the propositus. Furthermore, upon comparing peripheral blood and myelograms of the neonate at the time of birth, we found a low myeloid cells/erythroid cells ratio, undifferentiated erythroblasts, and reduced megakaryocytes. On the basis of these findings, we suggest that cell surface antigen is involved in the HDN caused by anti-Jra, and that a cytodifferentiation abnormality is present in the hematopoietic system.

Incidence of clinically significant antibodies in patients and healthy blood donors: a prospective cross-sectional study from a tertiary healthcare center in India.

INTRODUCTION: Since there is scarce data available on incidence and type of irregular antibodies in patients and donors in India, a study was undertaken to find the incidence of irregular antibodies in patients and irregular antibodies and a positive Direct Antiglobulin Test (DAT) in blood donors. MATERIALS AND METHODS: Antibody screening was performed using commercial pooled "O" cells and three-cell panel for donors and patients respectively and an 11-cell panel for identification using Column Agglutination Technology (CAT) with Low-Ionic-Strength Saline-Indirect Antiglobulin Test (LISS-IAT) technique (Ortho Clinical Diagnostics, Johnson & Johnson, USA). The cassettes used were Anti-human Globulin (AHG) type. DAT on donors was also performed using the AHG cassettes. RESULTS: Cumulative incidence of irregular antibodies amongst patients (n=32,560) and donors (n=31,367) were 0.12-0.009%, respectively. In patients, the commonest antibodies were from Rh system with anti-D being the most common antibody type (14/40; 35%) while in donors it was the MNS system with anti M (2/3) being the most common. Incidence of a positive DAT amongst the healthy blood donors was 0.04% (n=13/32,560). DISCUSSION: Incidence of irregular antibodies in patients at 0.12% was slightly lower than published reports and could be because of the fact that the patient population studied comprised largely of surgical patients many of whom have never received blood transfusion. This data could also be more representative since the number of patients studied was much higher as compared to the previous Indian studies (32,560 vs. 531-2026). The report on incidence of irregular antibodies and DAT (0.009-0.04%) in blood donors was first such attempt in India.

Manejo de la embarazada con isoinmunización por anticuerpos irregulares / Pregnant management by isoimmunized irregular antibodies

La isoinmunización eritrocitaria feto-materna se define como la presencia de anticuerpos maternos dirigidos contra antígenos presentes en los glóbulos rojos fetales. Los anticuerpos maternos pueden atravesar la barrera placentaria y provocar hemólisis de los glóbulos rojos fetales produciendo anemia hemolítica e hiperbilirrubinemia, características de la enfermedad hemolítica perinatal (EHP). La principal causa de EHP es la incompatibilidad ABO, seguida de la isoinmunización por RhD; esta última ha disminuido su incidencia dado el amplio uso de inmunoglobulina anti D. Sin embargo, el glóbulo rojo tiene más de 400 antígenos, muchos de ellos (>50) capaces de producir isoinmunización y EHP. En este artículo, revisamos la evidencia y proponemos un algoritmo de manejo y seguimiento de las embarazadas con isoinmunización por anticuerpos irregulares. En la isoinmunización por anticuerpos irregulares, los títulos de anticuerpos maternos no se correlacionan con la gravedad de la enfermedad. La anemia en la EHP por anticuerpos anti-Kell es secundaria a una supresión de la eritroblastosis fetal a diferencia del resto de los sistemas que producen anemia hemolítica. Recomendamos efectuar tamizaje de todas las pacientes en el control prenatal, solicitando grupo sanguíneo, Rh y test de Coombs indirecto. En las pacientes Rh (+) con test de Coombs indirecto positivo es necesario identificar los anticuerpos irregulares. En caso de tener isoinmunización por anticuerpos irregulares con riesgo de EHP, derivar a una unidad de alto riesgo obstétrico para realizar seguimiento de la aparición de anemia fetal midiendo de modo seriado el peak sistólico de la arteria cerebral media. Si se detecta anemia fetal, debemos planificar una cordocentesis para confirmar el diagnóstico y tratar la anemia.

The fetomaternal erythrocyte isoimmunization is defined as the presence of maternal antibodies directed against antigens present in fetal red blood cells. Maternal antibodies can cross the placenta and cause hemolysis of fetal red blood cells causing hyperbilirubinemia and hemolytic anemia, known as perinatal hemolytic disease (PHD). The main cause of PHD is ABO incompatibility, followed by RhD isoimmunization. The latter has decreased its incidence since the widespread use of anti-D immunoglobulin. However, the red cell has more than 400 antigens; many of them (>50) can lead to isoimmunization and PHD. In this article, we review the evidence and propose an algorithm for the management and monitoring of pregnant women with irregular antibodies isoimmunization. In the isoimmunization by irregular antibodies, maternal antibody titers do not correlate with the severity of the disease. Anemia in PHD by anti-Kell is secondary to suppression of fetal erythroblastosis unlike other systems that produce hemolytic anemia. We suggest the screening of all patients in the prenatal control with blood group, Rh and indirect Coombs test. In the Rh (+) patients with positive indirect Coombs test, irregular antibodies should be identified. In case of immunization by irregular antibodies in risk of PHD, the women should be referred to a high-risk obstetrics where the appearance of fetal anemia should be seek by measuring systolic peak of middle cerebral artery. If anemia is detected full confirmation of diagnosis and treatment should be effected by cordocentesis.

Red Cell Alloantibodies in Multiple Transfused Thalassaemia Patients.

BACKGROUND: Thalassaemia major patients require lifelong transfusion support due to which they are prone for alloimmunization to foreign RBCs. Alloimmunization can be prevented by extended phenotype match blood transfusion. The study was conducted to know the extent of problem of alloimmunization and to find important red cell antibodies in thalassaemia patients. METHODS: A cross-sectional study was conducted. A total of 32 thalassaemia patients were enrolled. The specimen was subjected to red cell alloantibody and autoantibody by column gel agglutination technique. R 1 (w) R 1 , R 2 R 2 , rr (papaine and non papain) and 11 cell panel reagent cells were used in screening and identification of alloantibodies respectively. RESULT: Six (18.8 %) subjects were alloimmunized. All alloimmunized subjects were recipient of more than 20 units of transfusion. Total seven clinically significant alloantibodies were identified. Anti E and anti c were commonest antibodies in four (12.5%) patients. CONCLUSION: Red cell alloimmunization is an important risk in thalassaemia patient. 71.4% of alloantibodies were anti E and anti c type. Extended phenotype match blood transfusion for Rh-c and Rh-E antigens or level 2 antigen matching stringency needs to be explored in preventing alloimmunization in thalassaemia patients.

Irregular antibody found during emergency subarachnoid hemorrhage operation : A case report

Irregular or unexpected antibodies are alloantibodies against serum or red blood cells after previous exposure to transfusion. When encountered in critical condition, however, risk of ongoing complication is not entirely predictable. Rapid transfusion of safe blood is thus, crucial not to compromise further procedure. A 78-year-old ASA IV man presented with Hunt-Hess grade IV subarachnoid hemorrhage with huge temporal bleeds. While in operating room, his blood pressure dropped when the dura was opened. Meanwhile, routine screening of blood typing repeatedly denoted Rh+O with irregular antibodies. Soon, compatible cross-matched blood was infused with 37 degrees C normal saline 200 ml at a rate of 4-5 ml/kg/hr. There was no laboratory evidence of hemolytic transfusion reaction. Postoperatively, BUN and creatinine increased slightly, but urination and respiration were unremarkable.

Búsqueda e identificación de anticuerpos irregulares en la población de Antofagasta / Screening and identification of irregular antibodies in population of Antofagasta

In the last years, the medicine transfusional has generated big advances in the area of the conservation and managing of the blood fractions, especially in the detection of incompatibilities between donors and recipients, using monoclonal antibodies powerful and new methods that detect antibodies in very low concentrations. The majority of the blood banks agree to provide compatible blood for the antigens ABO and Rho (D), because opposite to them the antibodies produce the more severe transfusional reactions. Nevertheless, there are many reactions that seemingly slip by for the clinical one in 4 hours later to the transfusion, period in which a narrower alertness is had in the patient. These antibodies (irregular antibodies) involved in many late reactions are capable of haemolyse red cells incompatible after 12, 24 or up to 72 hours of realized the transfusion, causing the death to the patient when the haemolysis is intravascular, without its manages to suspect that the reason was a reaction transfusional. This work had as general aim detect and identify the presence of irregular antibodies in samples tried of recipients and donors of the Bank of Blood of the Regional Hospital of Antofagasta, proving that the major number corresponded to the system Kell, with an incident of 25.42% of the Anti K O positive, 16.95% of the Anti K A positive.

En los últimos años, la medicina transfusional ha generado grandes avances en el área de la conservación y manejo de las fracciones sanguíneas, especialmente en la detección de icompatibidades entre donantes y receptores, utilizando antisueros monoclonales potentes y nuevos métodos que detectan anticuerpo concentraciones muy bajas. La mayoría de bancos de sangre se conforman, con proporcionar sangre compatible para los antígenos ABO y (D), porque frente a ellos los anticuerpos producen las reacciones transfusionales más severas. Sin embargo, hay muchas reacciones que aparentemente pasan inadvertidas para el clínico en las 4 horas posteriores a la transfusión, período en el que se tiene una vigilancia más estrecha en el paciente. Estos anticuerpos (anticuerpos irregulares) implicados en muchas reacciones tardías son capaces de hemolizar eritrocito es incompatibles después de 12, 24 o hasta 72 horas de realizada la transfusión, ocasionando la muerte al paciente cuando la hemólisis es intravascular, sin que se llegue a sospechar que la causa fue una reacción transfusional. Este trabajo tuvo como objetivo general detectar e identificar la presencia de anticuerpos irregulares en muestras procesadas de receptores y donantes del Banco de Sangre del Hospital Regional de Antofagasta, resultando que el mayor número correspondió al sistema Kell, con una incidencia de 25,42% del Anti K O positivo, 16,95% del Anti K A positivo.

Freqüência de anticorpos irregulares em politransfundidos no Hemocentro Regional de Uberaba-MG, de 1997 a 2005 / Frequency of irregular antibodies in multiple-transfused patients at the Regional Blood Bank of Uberaba, from 1997 to 2005

A fenotipagem eritrocitária pré-transfusional é um importante procedimento para aumentar a segurança das transfusões sangüíneas, sendo realizada rotineiramente no Hemocentro Regional de Uberaba-MG (HRU) desde 1996. O presente trabalho tem como objetivo geral avaliar a freqüência de anticorpos antieritrocitários irregulares em politransfundidos, de 1997 a 2005. Através de estudo retrospectivo foram levantados dados no arquivo do HRU de todos os pacientes aloimunizados, realizou-se análise estatística descritiva e comparam-se as proporções pelo teste "Z". Dos 23.220 transfundidos no período, com média de 5,7 transfusões por paciente, observou-se a ocorrência de aloimunização em 173 (0,75 por cento). Os sistemas Rh e Kell juntos tiveram freqüência superior a 70 por cento. A proporção do anti-D foi significativamente maior nas mulheres (p<0,05) e não houve diferença no sistema Rh entre brancos e não-brancos. Quanto à faixa etária, 70 por cento tinham mais de 30 anos. Dos 73 pacientes que tiveram a doença de base registrada, 39,73 por cento eram portadores de anemias agudas, 31,51 por cento de anemias crônicas e 28,77 por cento de doenças oncológicas ou onco-hematológicas. Aproximadamente 70 por cento dos anticorpos foram identificados até a décima transfusão. A baixa ocorrência da aloimunização no HRU reforça a importância da fenotipagem eritrocitária para todos os pacientes dependentes de transfusões crônicas, bem como da sua implantação na rotina de todos os serviços de hemoterapia.

Testing of the pre-transfusional blood phenotype, which has been carried out at the Regional Blood Bank in Uberaba since 1996, is an important procedure to improve safety of blood transfusions. This study aims to describe the frequency of irregular red blood cell antibodies in multiple-transfused patients from 1997 to 2005. In a retrospective study, data from all alloimmunized patients were collected from the blood bank files. Descriptive statistical analysis was performed and a comparison of proportions was made using the Z test. Alloimmunization was observed in 173 (0.75 percent) of the 23,220 transfused patients, with an average of 5.7 transfusions per patient. The frequency of the Rh and Kell systems jointly was over 70 percent. The proportion of anti-D was significantly higher in women (p<0.05) and no difference was noted in the Rh system between Caucasians and non-Caucasians. Seventy percent (70 percent) of the patients were over 30 years of age. Out of the 73 patients with registered diseases, 39.73 percent had acute anemias, 31.51 percent chronic anemias and 28.77 percent oncological or onco-hematologic diseases. Approximately 70 percent of antibodies were discovered before the 10th transfusion. The low frequency of alloimmunization observed at the Regional Blood Bank of Uberaba reinforces the importance of pre-transfusional blood phenotype screening for all multiple-transfused patients as well as its adoption as a common practice in all hemotherapy center.

Irregular Antibody Positivity in Women Blood Donors with History of Parturition / 대한수혈학회지

BACKGROUND: Antibody screening for donated blood is not yet being performed in Korea. Positive rate of irregular antibodies in Korean patients or blood donors has been thought to be much lower than that of foreign contries. We studied to know the actual frequency of irregular antibodies in blood donors with history of parturition using gel card, which was recently introduced in the field of blood banking and considered to be easy to standardize and sensitive to detect irregular antibodies. METHODS: 706 samples were collected from four blood centers in Seoul for 4 months. Antibody screening and identification were done by two kinds of Gel Card (DiaMed-ID corp, DiaMed, Murten, Switzerland) such as Nacl/Enzyme and LISS/Coombs' card. Adsorption- elution test was done in samples of which we could know the antibody specificity. RESULTS: Irregular antibodies were identified in 24 cases among 706 samples, therefore the overall frequency was 3.4% (95% CI: 3.4% +/- 1.3%). Only 4 cases, however, showed positive reaction in both enzyme and Coombs' phase, therefore frequency of clinically significant antibodies was 0.57% (95% CI: 0.57% +/- 0.55%). The identified irregular antibodies were anti-Lea (8 cases), Anti-Rh (3 cases) and Anti-P1 (1 case). Adsorption-elution test showed positive reaction only in 3 cases with anti-Rh antibodies. CONCLUSION: Considering that blood donors with history of parturition comprize just little proportion of total donors in Korea and frequency of irregular antibody is relatively lower than that of foreign countries in same group (0.57% vs 3.8%), it can be concluded that antibody screening be not urgent problem in Korean blood donation program.