Cohn, Claudia S.

AbstractBackgroundThe SARS‐CoV‐2 pandemic disrupted hospital operations, affected the blood supply, and challenged the health care system to develop new therapeutic options, including convalescent plasma (CCP). The aim of this study is to describe and analyze blood supply fluctuations and the use of convalescent plasma in 2020.MethodsAABB distributed a weekly and biweekly questionnaire through email to hospital‐based members (HBM).ResultsThe survey was sent to 887 HBM with 479 unique respondents, most of the hospitals served pediatric and adult patients, and all states of the country participated, except Idaho and Vermont. Fifty four percent of HBM reported increased wastage in the early phase of the pandemic (May), which decreased to 4% by the end of June and throughout the rest of the year. The majority of HBM reported receiving alerts from their blood suppliers reporting blood shortages throughout the year. During March and April, only 12% of HBM were performing elective surgical procedures. The top reasons to delay procedures were: bed availability (28%); COVID‐19 caseload (23%; and blood availability (19%). By mid‐April, 42% HBM had transfused CCP and reported >24 h delay in getting the units; the vast majority obtained CCP using the Expanded Access Protocol, and later, the Emergency Use Authorization. HBM consistently prioritized the most severe patients to receive CCP, but the proportion of severely ill recipients fell from 52% to 37% between May and October, with an increase from 5% to 21% of HBM providing CCP transfusion early in the course of the disease.DiscussionBlood utilization and availability fluctuated during the pandemic. The fluctuations appeared to be related to the number of COVID‐19 in the community. The use and regulatory landscape of CCP rapidly evolved over the first 8 months of the pandemic.

BACKGROUNDSingle antigen bead (SAB) assays are used to identify human leukocyte antigen (HLA) antibodies in patients with platelet refractoriness due to HLA Class I alloimmunization. Some laboratories use serum pretreatment regimens to eliminate interference from immunoglobulin M antibodies and complement. These modifications may contribute to interlaboratory variability, which is a recognized problem with the SAB assay.STUDY DESIGN AND METHODSFive patientsʼ sera were overnight shipped to 12 laboratories in the United States and internationally. Recipients used their labʼs SAB procedure to identify HLA Class I antibodies. The resultant mean fluorescence intensity (MFI) data were compared by instrumentation, bead lot, and pretreatment regimens. Laboratory‐specific cutoffs for positive antibodies were applied to the results.RESULTSInterlaboratory variability for MFI values appears to be associated with different pretreatment regimens. The coefficient of variation (CV) of MFI from samples pretreated with ethylenediaminetetraacetic acid, dithiothreitol, or heat inactivation (EDHI) were similar, ranging from 14% to 56% (mean, 22%). For samples with no pretreatment, the CVs were significantly higher than EDHI‐treated samples, ranging from 25% to 74% (mean, 39%; 95% confidence interval, 12.10‐21.90; p < 0.0001). An intralaboratory comparison of pretreatment regimens confirmed these findings. Some positive antibody specificities present in EDHI‐treated samples were negative in corresponding samples with no pretreatment when laboratory‐specific cutoffs for positive antibodies were applied.CONCLUSIONOur results show that greater interlaboratory precision can be achieved when samples are pretreated with EDHI as opposed to no pretreatment, likely because these pretreatments eliminate interference from inhibitors. Inhibitors may mask antibodies, leading to missed (or uncalled) specificities when no pretreatment is used.

BACKGROUNDABO‐incompatible platelet transfusions are common, and transfusions with ABO‐incompatible plasma are increasing with the use of group A plasma and group O whole blood (WB) in emergencies. Many centers screen blood products for anti‐A and/or anti‐B titers to help prevent hemolysis from ABO‐incompatible transfusions, yet titer methods and definition of high titers are not standardized.STUDY DESIGN AND METHODSThis international multicenter study collected data on anti‐A and anti‐B titer practices for plasma, apheresis platelet (AP), and WB units from January 2015 through December 2017 to determine the prevalence of high‐titer units using local definitions.RESULTSA total of 87,701 plasma, AP and WB units were screened for high‐titer anti‐A and/or anti‐B. High‐titer detection rates for group A plasma ranged 0%–13.6%; group A AP 2.7%–9.3%; group O AP 2.3%–65.7%; and group O WB 6.4%–20.7%. At the one center that collected group B AP, the high‐titer rate was 10.9%. High‐titer rates varied from month to month, as well as between years for a given month. There was no clear pattern of when high‐titer units were donated.CONCLUSIONThe prevalence of high‐titer plasma, AP, and WB units varies by titer method and local definition of high titer. Even at the lowest titer threshold of 50, a significant proportion of units had a high‐titer antibody, although the clinical relevance of this finding needs further investigation.

BackgroundPlasma constituents have been implicated in some types of platelet (PLT) transfusion reactions. Leukoreduced apheresis PLTs stored in InterSol have 65% less plasma than apheresis PLTs stored in 100% plasma (PPs). This study compared transfusion reaction rates in InterSol PLTs (PLT additive solution [PAS] C) versus PPs.Study Design and MethodsThe study design was an open‐label, nonrandomized retrospective review. Statistical methods were applied to substantiate noninferiority and superiority of PAS C compared to PP in terms of transfusion reaction rates. Adverse reactions (ARs) were categorized using the Biovigilance Component of the National Healthcare Safety Network. Active surveillance was used to monitor all transfusions, both with ARs and without ARs.ResultsA total of 14,005 transfusions from six study sites were included, with 9845 PP transfusions given to 2202 patients and 4160 PAS C to 1444 patients. A total of 165 ARs were reported. Percentages of transfusions with ARs were 1.37% for PPs, 0.55% for PAS C, and 1.13% overall. The relative risk (RR) for PAS C versus PPs was calculated as 0.403 with an upper confidence limit (UCL) of 0.663. Overall, ARs with the highest incidence were allergic transfusion reactions (ATRs) and febrile nonhemolytic transfusion reactions (FNHTRs), at 0.66 and 0.40% of total transfusions reported, respectively. The relative risks (UCLs) for ATRs and FNHTRs, respectively, were 0.350 (0.686) and 0.336 (0.827).ConclusionsPAS C PLTs were statistically superior and noninferior to PPs with respect to the transfusion‐related AR rate. PAS C noninferiority and superiority were also demonstrated for ATRs and FNHTRs, separately.