Transfusion最新文献

Background: IgG against alloantigens on transfused RBC can lead to antibody-mediated immune enhancement (AMIE). AMIE has properties not found in other forms of alloimmunization, including rapid clearance of RBCs, a requirement for Fc-gamma receptors on dendritic cells, and no dependence on IFNAR. A spleen is required for alloimmunization to transfused RBCs under normal conditions but its role in AMIE has not been assessed.

Study design and methods: Mice with surgical splenectomy or sham surgery were infused with monoclonal IgG against model antigens (HOD or KEL) followed by a transfusion of respective transgenic RBCs. Antibody binding to transfused RBCs, antigen-modulation, and RBC clearance were assessed by flow cytometry. IgM and IgG to the HOD and KEL alloantigens were quantified by flow cytometry-based crossmatch.

Results: IgG to either HOD or KEL caused brisk clearance of RBCs with almost complete antigen modulation at 24 h and a strong enhancement of both IgM and IgG in sham-operated animals. In splenectomized animals, AMIE was eliminated; antigen-modulation occurred but with decreased kinetics and magnitude; and RBC clearance was the same as in sham animals.

Conclusions: The current study extends the role of spleen as a general requirement for all known pathways of RBC alloimmunization studied thus far. However, the dissociation of clearance and antigen-modulation from AMIE shown in the current study raises the possibility that antigen-modulation and AMIE are correlated due to a confounding common cause (i.e., IgG binding RBCs).

Background: We investigated whether frequent apheresis donors have altered risk of bone fractures, and prescription of osteoporosis medicine//s due to their repeated exposure to citrate anticoagulant.

Methods: We used the Sax Institute's 45 and Up Study data linked with blood donation and other health-related datasets. We used a "5-year qualification period" method to identify active donors who donated at least one (any type) donation in the first and fifth year of the "qualification period." We categorized donors into 0, 1-29, and 30+ donation groups based on the number of apheresis donations made during the qualification period. We then compared the risk of bone fractures, and initiation of osteoporosis medicine/s in the years following the "qualification period" between the groups, using Cox proportional-hazards models including several potential confounders.

Results: A total of 7369 donors met the qualification criteria, of which 2033 (27.6%) made at least one apheresis donation. Of those donating by apheresis, 381 (18.7%) also made platelet as well as plasma donation, and rest donated plasma only. The median follow-up time for overall bone fractures was 5.49 years/per-donor (Q1-Q3, 5.27-5.95). In the fully adjusted models, compared to donors not making any apheresis donation, the hazard ratio for all-cause bone fractures, osteoporotic bone fractures, and initiation of osteoporosis medicine/s in donors donating 30+ apheresis donations was 0.96 (95% CI: 0.58-1.60), 0.73 (95% CI: 0.29-1.82), and 1.09 (95% CI: 0.66-1.81), respectively.

Conclusions: We did not observe a statistically significant change in risk of bone fractures, and initiation of osteoporosis medicine/s in frequent apheresis donors predominantly consisting of plasmapheresis donors.

Background: Donors on testosterone replacement therapy (TRT) may require frequent whole blood donation due to erythrocytosis, but FDA guidelines prevent the transfusion of plasma-based products from these donors. This study surveyed TRT donor testosterone levels in whole blood components and evaluated a possible mitigation strategy with a pathogen reduction technology using UVA light and compound adsorption device (CAD) steps.

Study design and methods: Whole blood from male TRT donors and controls were processed into red blood cells and plasma components. Free and total testosterone were measured in 78 TRT donors and 48 controls by high-performance liquid chromatography-tandem mass spectrometry. Pathogen reduction (INTERCEPT Blood System) on pooled plasma components (n = 10) with supraphysiologic testosterone were sampled: before treatment, after UVA illumination, and after CAD incubation.

Results: TRT donors had 3.8 and 3.9 times more free testosterone in plasma and red blood cell supernatant, respectively, and 2.3 times more total testosterone in both components than controls (p < .0001). Two controls and 33 TRT donors had supraphysiologic testosterone. The CAD incubation reduced the mean free and total testosterone by 88% (571.72-73.8 pg/mL) and 84% (1498.61-240.59 ng/mL), respectively (p = .0065), but UVA light had no effect (p > .9999).

Discussion: TRT donors had significantly higher testosterone levels than controls. The CAD step in the pathogen reduction process abrogated supraphysiologic testosterone in plasma at or below the reference range. Studies validating testosterone removal from plasma can support the transfusion of pathogen-reduced plasma and platelets from TRT donors.

Background: Cold agglutinin disease (CAD) or syndrome (CAS) can be particularly challenging when autologous stem cell transplant (ASCT) is needed. Standard peripheral blood stem cell (PBSC) collection and manipulation involve ex vivo blood manipulations at lower than body temperature, predisposing to agglutination during graft collection, handling, processing, and infusion.

Study design and methods: We describe the first case of ASCT for relapsing lymphoma in a patient with high-titer CAD requiring anti-complement therapy and chronic transfusion. To prevent agglutination, five therapeutic plasma exchange sessions were performed prior to PBSC collection. Optimal thermal conditions were maintained using various approaches to increase the temperature of the room, venous return lines, and the apheresis device. Ex vivo graft manipulation was conducted under similar conditions. An infusion test was performed with a fraction of the graft a month prior to ASCT to confirm tolerability.

Results: The infusion test was performed without complications. A month later, the patient was admitted for ASCT. The aplasia phase was particularly challenging, as the patient experienced a rapid drop in hemoglobin levels due to hemolysis without compensatory reticulocytosis. Twelve months after ASCT, chronic hemolysis persists, but the patient is now transfusion-free, and the lymphoma remains in remission.

Discussion: Performing ASCT in patients with clinically significant CAS or CAD is challenging but can be done safely. Strong coordination between the apheresis team, cell therapy laboratory, and clinical unit is paramount to the success of this procedure. The experience gained from this case may also be applicable to other cell therapy procedures.

Background: US blood donors are tested for syphilis because the bacterial agent is transfusion transmissible. Here we describe trends over an 11-year period of donations positive for recent and past syphilis infections, and donations classified as syphilis false positive (FP).

Methods: Data from January 1, 2013, to December 31, 2023 (11 years) were compiled for all American Red Cross blood donations to evaluate demographics/characteristics and longitudinal trends in donors testing syphilis reactive/positive. The prevalence of recent, past, and total (combination of recent/past) infections were evaluated, along with syphilis FP donations. Classification was based on known serological methods using treponemal and non-treponemal tests.

Results: Approximately 53 million donations were included with 10,365 total syphilis infections (3463 recent and 6902 past; 0.02% total) and 48,719 FP (0.09%). Donor demographics, characteristics, and HBV/HCV/HIV nucleic acid testing reactivity differed among syphilis-positive and FP compared with nonreactive donations. Donors with a FP donation had high rates of subsequent donations testing syphilis positive (0.3%) and FP (7.7%). Median time from first FP to subsequent FP was observed to be 3.6 months. Recent infections increased over the 11 years, with past infections peaking in 2014 followed by increases in 2021-2023 paralleling recent infections. Repeating cycles of seasonal FP spikes occurred in the fall of 2013 and from 2017 to 2022 corresponding with vaccine administrations.

Conclusions: Syphilis infections in blood donors are trending upward, paralleling US population trends. Syphilis FP donors had high rates of subsequent FP and unexplained syphilis-positive donations. Seasonal syphilis FP spikes occurred for most years but are trending downwards.

Background: The Association for the Advancement of Blood and Biotherapies (AABB) conducted a global survey of patient blood management (PBM) practices. It determined changes in PBM practices since the last survey.

Study design and methods: A working group of AABB's PBM Subsection and AABB staff designed the survey using the Qualtrics™ platform. The survey collected data from January 1, 2021, through December 31, 2021, and data analysis was conducted.

Results: Responses were received from 274 facilities across five World Health Organization (WHO) regions, from which 205 (74.8%) were from North America (NA), and 25.2% (69/274) were from outside of NA or the rest of the world (RoW). Of all respondents, 46.0% (126/274) had a PBM program. NA at 50.2% (103/205) was significantly higher than RoW at 33.3% (23/69) (p = .0049). In NA AABB transfusion guidelines, 36.8% (179/486) were the most followed versus RoW, with the Ministry of Health at 23.2% (29/125). The hemoglobin transfusion threshold of ≤7.0 g/dL (inpatients and outpatients) and platelet transfusion threshold of 5000/μL -10,000/μL (prophylaxis for inpatients and outpatients) were most commonly followed. Areas of improvement since the last AABB 2013 survey included providing PBM training increased to 61.7% (103/167) from 36.5% (219/600) and evaluation of patients undergoing elective surgical procedures for factors predictive of anemia to 46.0% (125/272) from 28% (144/507).

Conclusions: While gains have been made in certain areas of PBM, there remains room for improvement, as more than half of respondents did not have a PBM program.

Background: Red blood cell (RBC) utilization in patients with sickle cell disease (SCD) in Canada is poorly defined. This study describes RBC utilization in an SCD cohort at a single Canadian center.

Study design and methods: All adults with SCD who received care at the Ottawa Hospital between January 2006 and May 2019 were included, and followed until December 2021. Data on hospital encounters and RBC transfusions were obtained from hospital databases.

Results: Overall, 273 patients were included (median age: 25 years; 53.8% female; median follow-up: 8.1 years). During the study period, there were 23,127 hospital encounters (median: 45 [interquartile range (IQR) 18, 100] per patient), with 165 patients (60.4% of cohort) receiving 22,538 RBC units. Most RBC units (86.5%) were transfused in the outpatient setting. Although only 2.9% of patients had O-negative blood type, O-negative RBC units accounted for 29.1% of units transfused. One hundred forty-seven patients received 2205 RBC units (9.8% of total) as simple transfusions (median: 5 [IQR 3, 13] per patient), and 88 patients received 20,333 RBC units (90.2% of total) during 2702 red cell exchange (RCE) sessions (median: 14.5 (IQR 1, 47.5) RCE per transfused patient). A median of 7 RBC units (IQR 6, 9) were transfused per RCE session, with a median of 30 days (IQR 28, 40) between sessions.

Discussion: Patients with SCD at our center frequently received O-negative units, and large RBC volumes were used for RCE. These results provide a utilization baseline for future education and quality improvement initiatives to optimize RBC stewardship.

Background: The Association for the Advancement of Blood and Biotherapies guidelines recommend the use of high-titer COVID-19 convalescent plasma (CCP) for patients with SARS-CoV-2 at high risk of disease progression, including those who are immunocompromised. We hypothesized that conventional plasma units have comparable neutralizing antibody levels to CCP.

Study design and methods: Conventional plasma and CCP units were obtained from blood suppliers. Quantitatively measured antibodies to SARS-CoV-2 were assessed using the MesoScale Discovery multiplex electrochemiluminescence immunoassay. Binding antibody distributions were compared with Wilcoxon rank-sum tests. SARS-CoV-2 neutralizing antibodies were analyzed using the GeneScript ELISA-based neutralization assay. The proportion of conventional and CCP units with a percent signal inhibition of ≥80% (as defined by the United States Food and Drug Administration for CCP in 2021) and exact binomial confidence intervals (CIs) were calculated.

Results: Among 218 conventional plasma units and 74 CCP units collected between September 2023 and July 2024, the distribution of total antibody binding levels largely overlapped between conventional plasma and CCP, though statistically significant differences in median nucleocapsid and spike Omicron variant concentrations were observed. Median percent signal neutralization was 97.5% (range 3.4%-98.6%) among conventional plasma units and 97.7% (range 95.4%-98.6%) among CCP units. For conventional plasma, 95.0% (95% CI = 91.2%-97.5%) met the neutralization antibody threshold for high-titer CCP. For CCP, 100% (95% CI = 95.1%-100.0%) met the neutralization threshold for high-titer CCP.

Conclusion: Conventional plasma units demonstrate similar median antibody concentration to CCP units. In countries or regions where licensed CCP is unavailable and titers are unknown, transfusion of multiple conventional plasma units may be of clinical utility.