Transfusion最新文献

Background: The Rh blood group system (ISBT004) is encoded by two homologous genes, RHD and RHCE. Polymorphism in these two genes gives rise to 56 antigens, which are highly immunogenic and clinically significant. This study extended previous work on the establishment of RHD allele specific reference sequences using next generation sequencing (NGS) with the Ion Personal Genome Machine (Ion PGM) to sequence the complete RHCE gene.

Study design and methods: Genomic DNA (gDNA) samples (n = 87) from blood donors of different serologically predicted genotypes including R₁R₁ (DCe/DCe), R₂R₂ (DcE/DcE), R₁R₂ (DCe/DcE), R₂R_Z (DcE/DCE), R₁r (DCe/dce), R₂r (DcE/dce), R₀r (Dce/dce), rr (dce/dce), r'r (dCe/dce), and r″r (dcE/dce) were used in this study. The RHCE gene was amplified through overlapping long range-polymerase chain reaction (LR-PCR) amplicons and then sequenced with the Ion PGM. Data were analyzed against the human genome reference sequence build hg38 and variants were called.

Results: Referen variant allel VS. In addition to the RHCE reference alleles, different exonic single nucleotide variants (SNVs) were detected that encode known RHCE variant alleles including RHCE*Ce.09, RHCE*ceAR, and RHCE*ceVS.03. Numerous intronic SNVs were detected and compared from samples with different Rh genotypes, to determine their link to a specific Rh haplotype. Based on the exonic and intronic changes detected in different RHCE alleles, three RHCE reference sequences were established and submitted to Genbank (one for the RHCE*Ce allele, one for the RHCE*cE allele, and one for the RHCE*ce allele).

Conclusion: Intronic SNVs may represent a novel alternative diagnostic approach to investigate known and novel variants of the RH genes and the prediction of Rh haplotype.

Background: Reports of cases of bacterial infection due to transfusion of red blood cell (RBC) components (RBC-TTBI) are relatively rare. Hence, the possibility of undetectable bacterial contamination in RBCs, especially by psychrotrophic bacteria, must be clarified.

Study design and methods: We assessed nine psychrotrophic bacterial species, including those implicated in bacteremia or RBC-TTBIs. They were cultured on plates from 4 to 37°C to determine their optimal growth temperatures. We also assessed the detection capabilities of the automated culture/alarm system BACT/ALERT VIRTUO (VIRTUO) using BPA (aerobic) and BPN (anaerobic) bottles. In addition, bacteria-inoculated RBCs were incubated at 4°C for 42 days, with samples assessed weekly for bacterial growth using plate culture, VIRTUO, visual inspection, and endotoxin production.

Results: Two Psychrobacter species exhibited weak or no proliferation at temperatures ≥30°C in plate cultures. Three Pseudomonas species, one Psychrobacter species, and one psychrotrophic lactic acid bacteria proliferated in RBCs at 4°C, reaching 10⁴-10⁸ colony-forming units/mL (growth count) and 15-39,230 pg/mL (endotoxin production) by day 14. VIRTUO, operating at 36°C, failed to consistently yield reliable results for any of the tested bacterial species. Notably, visual changes in bag appearance were observed from day 21 in four species that proliferated in RBCs.

Discussion: Each psychrotrophic bacteria demonstrated a specific temperature preference for optimal proliferation. Standard culture tests, typically conducted at 35-37°C, often fail to detect the growth of such bacteria, suggesting they may be overlooked in the cultural analysis of suspected RBC-TTBI cases.

Background: Extracorporeal photopheresis (ECP) product characteristics are not well established. The aim of this study was to compare mononuclear cells (MNCs) collection using the new Amicus blue (AB) In-line ECP system to our standard Off-line ECP system using the Optia apheresis device and the MacoGenic G2 inactivation system (OM).

Study design and methods: We assessed the ECP products and procedure parameters, patient characteristics, and adverse events for both AB and OM systems in paired patients. Comparisons were made with t-test for paired samples.

Results: Thirteen patients underwent 15 double, paired procedures using both ECP protocols and processing the same blood volume of 4000 mL. Total MNC collected in the product were 51.6 × 10⁸ (95% CI 30.0-73.1) and 42.2 × 10⁸ (95% CI 22.4-62.0) for the AB and OM, respectively (not significant). Both products were also similar regarding volume, MNC concentration, purity, and hematocrit. However, total platelet count (×10¹¹) was significantly lower in the AB products: 0.25 (95% CI 0.15-0.36) versus 1.2 (95% CI 0.9-1.5). The new AB system reduced significantly also the time invested and anticoagulant used per procedure compared with OM, albeit with similar collection efficiency and percentage of MNC captured per procedure. Hypocalcemia was the commonest adverse event with both systems, but it was not severe.

Conclusions: The new AB system collected MNC products comparable to our current experience with OM, although in a significantly shorter time, with a reduced use of anticoagulant and lower contamination with platelets, which are all valuable advantages of the new system.

Background: Red cell exchange (RCE) is an important treatment for sickle cell disease (SCD). It is a resource-intensive intervention requiring large volumes of red blood cells (RBC), which are frequently antigen-matched. Efforts to reduce the volume of units transfused, while maintaining treatment efficacy is an important need. This study evaluates the impact of a change to isovolemic hemodilution (IHD)-RCE on RBC utilization in SCD patients at a Canadian center.

Study design and methods: Adult SCD patients receiving chronic automated RCE at the Ottawa Hospital were approached for study inclusion. To safely attain a meaningful reduction in transfused RBCs, RCE parameters were individualized for each patient. IHD-RCE was performed only if an estimated reduction in RBC volume of at least 200 mL was expected, with hematocrit not allowed to decrease below 20%. Data were compared in the 6-months before and after the protocol change.

Results: Twenty-two adult patients met the criteria for inclusion. There was a net reduction of 107 RBC units after the transition from standard RCE to IHD-RCE (1035 vs. 928 units; -10.3%). The mean number of RBC units transfused per patient decreased by 4.8 (47.0 vs. 42.2 units; p = .01). No difference in target post-RCE hemoglobin S levels was observed.

Discussion: In this study IHD-RCE reduced RBC utilization without impacting efficacy or safety, conserving 107 RBC units (an annualized savings of $95,444 CAD). No adverse events due to saline replacement were observed. Increased awareness of the benefits of IHD-RCE through knowledge translation could promote greater uptake.

Background: We reviewed trauma blood use at our US regional trauma center 2011-2022-including PROPPR trial participation 2012-2014 and initiation of whole blood availability in 2019-to assess the implementation of early coagulation support in acute trauma care.

Study design/methods: We identified all acute trauma patients recorded by our Trauma Registry as arriving at our large US regional Level 1 trauma center from April 6, 2011 (Blood Bank opening) through December 2022. Patient cohort data were then linked directly to Blood Bank final-product-issue date/time data to identify patients receiving any blood product in the first 24 h of care and then, specifically, at least one unit of Red Blood Cells (RBC), Plasma, or Whole Blood (WB). Results were binned as: "RBC first," "Plasma first," "Both at the same time," or "WB first."

Results: Over the study period, 73,634 acute trauma patients received care, and 12,927 received at least one unit of a blood product. The proportion receiving plasma or a combination of plasma and RBCs as the initial transfusion increased after 2015 from 33% to 66%, while the proportion receiving packed RBCs alone decreased from 57% to about 18%. Since its introduction in 2019, the use of WB as the first product has grown to 20%.

Conclusions: This retrospective cohort study documents the increasing use of plasma and now WB as initial products issued in trauma resuscitation, reflecting acceptance of coagulation support as the standard of care and the use of hemostatic resuscitation protocols.