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Despite the large number of serologically identified red cell antigens to date, it is reassuring to note that in the common clinical scenario, the transfusion laboratory would only likely deal with a narrow range of clinically significant antibodies to specific antigens of blood group systems. Accurate ABO and RhD typing still remains the most crucial step in pretransfusion testing followed by the antibody screen. The correct identification of single antibodies or multiple antibodies and whether they are alloantibodies or autoantibodies is necessary so that corresponding antigen-negative red cells can be supplied. Clinically insignificant antibodies or what some would denote as 'nuisance' antibodies would need to be differentiated from clinically significant antibodies. When discrepancies occur between forward and reverse ABO typing, it is crucial that laboratories resolve the discrepancy before a specific ABO blood group is assigned. The inclusion of O cells in reverse grouping, anti-H and anti-A1 lectins in the forward, performing the typing on a range of temperatures using washed red cells and careful interpretation of agglutination patterns, would usually provide an answer. On occasions, a saliva test may be necessary and rarely molecular typing. With regard to RhD typing, test systems should identify RhD-negative and D-variant individuals so that D-negative units can be issued to them. Testing with antisera from different clones, the use of adsorption-elution techniques and RhD.CcEe typing aids in coming to a conclusion, before molecular testing becomes necessary. Extended red cell phenotyping is indicated if the patient is at risk for developing a red cell antibody. [ABSTRACT FROM AUTHOR]

The article discusses the implications of genetic polymorphisms of human platelet antigens (HPA) in Asian population in the establisment of blood platelet donor registries. It states that HPA antigen causes the development of HPA alloantibodies implicated in platelet immune disorders including fetal and neonatal alloimmune thrombocytopenia, post-transfusion purpura, and multiple platelet transfusion refractoriness. The importance of HPA genotyping in developing platelet donor register is noted.

Background and Objectives Appropriate screening for irregular red-cell antibodies is essential for ensuring transfusion compatibility and for antenatal management of mothers at risk of haemolytic disease of the foetus and newborn. Screening for all relevant antibodies is, however, limited by screening cells that do not express antigens present in the patient and donor population. Technology to artificially incorporate antigens into red cells is currently available and may be an option for customizing screening cells. Materials and Methods We sought to identify retrospectively the changing patterns of alloantibody prevalence in our multiethnic population on change of screening cells. Antibody screening records of 143 501 patients tested from 2004 to 2010 were retrieved and divided into two groups: period-1 (2004-2008) and period-2 (2009-2010). During period-1, standard screening cells were used while in period-2, MUT+Mur+ KODE™ transformed red cells (kodecytes) were used. Results Four per cent of samples tested during period-2 were positive on antibody screening compared to 3·2% in period-1. Specific antibodies, excluding anti-D, were identified in 1·66% and 1·52% of patients in period-2 and -1, respectively. When confined to antibodies of clinical significance only, period-2 showed higher alloantibody prevalence of 1·16% as compared to 0·66% in period-1. Antibodies to glycophorin variants of MNS (vMNS) were more commonly detected while antibodies to Lewis antigens declined during period-2. Conclusion Antibodies to vMNS antigens are common in South and East Asian populations and are often missed when using standard screening cells. Use of specifically engineered screening cells to express red-cell antigens artificially is beneficial in detecting the diverse alloantibodies present in our population. [ABSTRACT FROM AUTHOR]

Individuals with α-thalassaemia (ATT), β-thalassaemia (BTT) and HbE trait (HET) are often initially identified based on haematological parameters. However, the values of these parameters usually overlap with iron deficiency anaemia (IDA) and anaemia of chronic disease (ACD). We evaluated the use of RBC-Y in 156 normal individuals and 332 patients; ATT ( n = 37), BTT ( n = 61), HET ( n = 25), HbH disease ( n = 5), ACD ( n = 67), IDA ( n = 83) and ACD with IDA ( n = 54). Diagnostic efficiency was analysed by receiver operating characteristics (ROC). MCH was better compared with RBC-Y in discriminating normal from abnormal with sensitivity and specificity of 94% at a cut-off of 26 pg. The Green and King (G&K) index performed the best in discriminating carriers from IDA and ACD with area under the ROC curve (AUCROC) of 0.81. However, if ACD was excluded, RBC-Y/MCV was a good discriminator for carriers from IDA with AUCROC = 0.845. In general screening of populations with ATT, BTT and HET, we propose that hypochromic individuals be first identified by MCH <26 pg and carriers distinguished within these hypochromic individuals from IDA by using RBC-Y/MCV. However, if the prevalence of ACD were high within the screening population, G&K index would be a more suitable discriminator. [ABSTRACT FROM AUTHOR]

Altitude training is sometimes employed by elite endurance athletes to improve their sea level performance. This improvement results from the increased red cell mass consequent upon the boost in erythropoietin (EPO) level that occurs as a response to the relatively hypoxic environment at high altitudes. We measured serum EPO levels together with various red cell and reticulocyte parameters including immature reticulocyte fraction (IRF) in eight national track-endurance cyclists, resident at sea-level, prior to and upon return from an altitude of approximately 1905 m. Reticulocytes and soluble transferrin receptor (sTfR) were significantly increased with reduction in ferritin levels immediately on return from high altitude indicating increased erythropoietic activity. IRF in particular showed a significant peak immediately on return but decline to sub-baseline levels by day 9, and recovery to baseline by day 16. Our results indicate that IRF is a sensitive marker of erythropoietic status in athletes undergoing altitude training and subsequent loss of EPO stimuli on return to sea level. [ABSTRACT FROM AUTHOR]

The co-occurrence of JAK2 V617F mutation with BCR-ABL reciprocal translocation is uncommon. We report a 60-year-old man who initially presented with phenotype of polycythemia vera (PV), which evolved into chronic myeloid leukemia and back to PV once treatment with imatinib was commenced. JAK2 V617F mutation and BCR-ABL fusion transcripts were detected in the initial sample. However, JAK2 V617F alleles diminished when BCR-ABL mRNA burden increased and reappeared once the patient was commenced on imatinib. The dynamic interaction between JAK2 V617F and BCR-ABL implies that two independent clones exist with the JAK2 V617F clone only achieving clonal dominance when BCR-ABL positive clones are suppressed by imatinib. [ABSTRACT FROM AUTHOR]