Evaluation of 2-column agglutination versus conventional tube technique for antibody screening

The study aimed to determine the specificity and sensitivity of the Ortho BioVue two-column agglutination system for the detection of low concentrations of clinically significant antibodies in serum. The BioVue system was compared with the conventional tube technique [LISS-Coombs indirect antiglobulin test], and the two-stage Papenzyme test was used to resolve discrepancies between the two methods. We tested 3000 serum samples from randomly selected patients at King Hussein Medical Centre. Both the antibody screening and identification gave negative results in 2952 patients and positive results in 48 patients. We found the BioVue system to be the more sensitive technique. However, if papain enzyme-treated cells were included in the conventional tube technique when applied to antibody screening and identification, both methods would be of comparable sensitivity

The utility of ‘home-made’ reagent red blood cells for antibody screening during pre-transfusion compatibility testing in Uganda

Background: The WHO recommends that pre-transfusion testing should include ABO/RhD grouping followed by screen- ing for red blood cell (RBC) alloantibodies using the indirect antiglobulin test (IAT). However, in Uganda, current practice does not include RBC alloantibody screening. Objective: To assess the utility of ‘home-made’ reagent RBCs in alloantibody screening. Materials and methods: In a laboratory-based study, group O RhD positive volunteer donors were recruited and their extended phenotype performed for C, c, E, e, K, Fya, Fyb Jkb, S and s antigens. These ‘home-made’ reagent RBCs were preserved using Alsever’s solution and alloantibody detection tests performed. For quality assurance, repeat alloantibody screening of patients’ samples was done at Bloodworks Northwest Laboratory in Seattle, United States. Results: A total of 36 group O RhD positive individuals were recruited as reagent RBC donors (median age, 25 years; range, 21 – 58 years; male-to-female ratio, 1.6:1). Out of the 311 IATs performed, 32 (10.3%) were positive. Confirmatory IAT testing in the United States was in agreement with the findings in Uganda. Conclusion: Use of ‘home-made’ reagent RBCs during pre-transfusion testing in Uganda is feasible. We recommend the introduction of pre-transfusion IAT alloantibody screening in Uganda using ‘home-made’ reagent RBCs to improve trans- fusion safety. Keywords: Blood transfusion; ‘Home-made’ reagent RBCs; Pre-transfusion testing; RBC alloantibody screening; Uganda.

A case study of a patient with anti-Yta alloantibodies against the high-prevalence antigen of red blood cells qualified for heart transplantation

The Yta antigen from the Cartwright blood group system is a high-prevalence antigen found in 99.8% of the population. The literature data shows that antibodies anti-Yta demonstrate the variable clinical significance and are rarely the cause of a hemolytic post-transfusion reaction. The study aims to present the difficulties related to the selection and sustainable supply of blood for transfusion for the patient of the Silesian Centre for Heart Diseases with anti-Yta alloantibodies, qualified for a heart transplant. If Yt(a-) blood is not available Institute of Hematology and Transfusion Medicine in Warsaw, referring to reports in the publications, allowed transfusion of the least incompatible red blood cells in indirect antiglobulin test. One hour after transfusion of leucocyte-depleted concentrate of red blood cells (RBCs), issued in accordance with the above recommendations by Regional Blood Donation Center in Katowice as the least incompatible, the patient was observed to experience symptoms of an adverse post-transfusion reaction. For subsequent transfusions, RBCs from Yt(a-) donors were selected, of which only eight were registered in Poland at that time. Medical decisions on RBCs transfusion in patients for whom no compatible blood can be selected is very difficult, and the benefits of incompatible transfusion should be weighed against the risk of possible complications. To avoid this, it should be remembered that the early identification of antibodies increases the chance of finding serologically compatible blood and in many cases allows to supply blood for a patient with autologous donations.

Rho(D) Immune Globulin (anti-D) Concentration-Time Curve After Antenatal Immunoprophylaxis in RhD-Negative Pregnant Women

Objectives: To assess anti-D concentration through maternal indirect antiglobulin test (IAT) titers and scores after RhD-negative pregnant women receive antenatal anti-D until delivery. Methods: Cross-sectional study. Twenty-seven RhD-negative pregnant women were evaluated after receiving a prenatal anti-D dose around 28th week of pregnancy. Serial blood samples were collected at 3, 7, 21, 42, 63 and 84 days after anti-D administration. We performed IAT by conventional tube test (CTT) and gel microcolumn assay (GMA) to assess anti-D scores and titers. Statistical analyzes were performed using IBM SPSS Statistics software. Results: Anti-D had maximum scores values ​around 7 days after its administration, and scores were higher in GMA than CTT for all patients. Anti-D was detected at delivery in 59% of the participants by IAT performed in GMA. Overweight and obese pregnant women may present lower concentrations of anti-D. No correlation was found between maximum scores when comparing them with these variables: newborn RhD blood type; maternal-fetal ABO incompatibility and the number of pregnancies. Conclusions: Administering 300 μg of anti-D in 28th week of pregnancy should be compared in studies analyzing perinatal outcomes, since anti-D was not detectable in 41% of patients, suggesting a significant period without prophylaxis.

Droplet-based blood group antibody screening with laser incubation

Complete indirect antiglobulin test (IAT) in a single diagnostic incorporating a laser-incubated droplet on a hydrophobic surface with read-out provided by a paper strip.

PREVALENCE OF BOMBAY BLOOD GROUP AMONGST THE HEALTHY BLOOD DONORS AT A TERTIARY CARE CENTRE IN WESTERN RAJASTHAN, INDIA

Introduction: The prevalence of Bombay (Oh Phenotype) is not precisely known in Rajasthan state. Because of the fact that Bombay blood group is clinically significant, we decided to conduct a study at our centre to determine the prevalence of Bombay blood group among blood donor population in Western Rajasthan. Methodology: This blood bank based prospective study was carried out amongst the blood donors over a period of 11 months, i.e., from February 2019 to December 2019. Total 30,000 donor samples were screened for ABO-RhD blood grouping and antibody screening. Auto control, indirect antiglobulin test (IAT) and Bombay blood group (Anti-H lectin) tests were run on all the O blood group samples showing agglutination with O reagent cells (in reverse grouping). Donors negative on Anti-H testing were tested for saliva A, B and H antigens and interpreted. Results: Out of the total 30,000 donors, the maximum number of donors had blood group B+ (32.76%), followed by O+ (29.9%), A+ (20.41%), AB+ (8.06%), B- (3.11), O- (3.02%), A- (1.93%) and AB- (0.8%). Prevalence of Bombay blood group among study population was calculated to be 0.003%. Conclusion: Bombay phenotype is a rare blood group but not uncommon. If serum grouping is not performed, it is misdiagnosed as blood group O. Therefore both forward and reverse blood grouping should be done on 100% samples. Keywords: Bombay, Anti-H lectin, Serum grouping, Blood donors.