STUDY DESIGN AND METHODS: Antibody testing results between the years 2013 and 2015 with relevant patient demographic data and red blood cell (RBC) transfusion history were retrieved. Cumulative alloimmunization incidence and evanescence to MUT and Mur were estimated by Kaplan-Meier analysis in relation to the number of RBC units transfused and time.
RESULTS: Of 70,543 selected patients, 6186 nonalloimmunized subjects with available antibody testing results posttransfusion were identified. Cumulative alloimmunization incidence for MUT increased from 0.12% (95% confidence interval [CI], 0.03-0.21) to 0.63% (95% CI, 0.25-1.01), while for Mur it increased from 0.04% (95% CI, 0-0.09) to 0.42% (95% CI, 0.05-0.79) when a patient was transfused 2 RBC units as compared to 12. Both antibodies had high evanescence rates and at 1 year, anti-MUT and -Mur will be detected in only 45% (95% CI, 35%-57%) and 27% (95% CI, 17%-43%), respectively, of previously positive patients. MUT and Mur immunogenicity was estimated to be 1.7 and 1.2 times higher than E when their rate of evanescence was taken into account.
CONCLUSION: Antibodies to MUT and Mur develop following multiple RBC exposures. Immunogenicity of MUT/Mur and evanescence rates of the corresponding antibodies is higher compared to anti-E. Appropriate selection of antibody screening cells is needed in view of the high prevalence, immunogenicity, and evanescence of the antibodies.
BACKGROUND AND OBJECTIVES: Blood centres often use the '30 or 60-min rule' for accepting RCC exposed to room temperature (RT) back into inventory. Effective monitoring of these temperature deviations is however lacking.
MATERIALS AND METHODS: A Timestrip PLUS® TP153 10°C (TS + 10) TTI was attached to RCC units after preparation of the unit in the blood bank or on issue to the ward, to track the CET > 10°C during laboratory processing and outside the transfusion laboratory.
RESULTS: The mean CET of 153 RCC tracked within the laboratory was 56 min. Sixty-four (41.8%) and 34 (22.2%) of RCC had core temperature (CT) >10°C for more than 30 and 60 min, respectively. Among the 69 RCC that were returned unused, 27 (39.1%), 17 (24.6%) and 5 (7.2%) RCC units had CT >10°C for more than 30, 60 and 120 min respectively.
CONCLUSION: A large proportion of RCC have CT >10°C exceeding 30 min during handling within the transfusion laboratory, as well as when RCC are returned unused from transfusion locations. Corrective measures should be implemented to better manage the cold chain to avoid undesirable consequences to blood transfusion. A temperature sensitive device that can also indicate CET can be employed to objectively monitor the period that RCC remained at a CT that exceeds 10°C.
MATERIALS AND METHODS: Ten blood collection agencies (BCAs) provided 12 months' data on donors who met eligibility criteria or were deferred, as well as details of their donation practices. Body mass index and blood volumes were calculated and analysed.
RESULTS: Data on 9,599,613 donations and 154,834 deferrals from six national and four regional BCAs revealed varied donation eligibility and collection practices. Seven used haemoglobin (Hb) criteria below the World Health Organization anaemia threshold. Seven accepted donors weighing <50 kg. Data collection on the weight and height of donors and on deferrals was inconsistent, often not routine. Deferred donors appear to weigh less, with corresponding lower estimated blood volume.
CONCLUSION: The diversity in eligibility criteria and donation practices reflects each BCA's strategy for balancing donor health with securing an adequate blood supply. Use of lower Hb criteria substantiate their appropriateness in Asia and indicate the need to define Hb reference intervals relevant to each population. We encourage routine gathering of donor weight and height data to enable blood volume estimation and local optimization of donation volumes. Blood volume estimation formulae specific for the Asian phenotype is needed. Information from this study would be useful for tailoring donation criteria of Asian donors around the world.