Seasonal increase in syphilis screening reactivity rates in whole blood donors, United States, 2011-2023.

BACKGROUND: In December 2021, the U.S. Food and Drug Administration published a letter to clinical laboratory staff and healthcare providers detailing a risk of false Rapid Plasma Reagin (RPR) when using the Bio-Rad Laboratories BioPlex 2200 Syphilis Total & RPR kit in people who had received COVID-19 vaccination; Treponema pallidum particle agglutination assays did not appear to be impacted by this issue. We evaluated reactivity rates of syphilis screening with negative confirmatory testing at our institution by year and seasonality. METHODS: We performed a retrospective study of routine syphilis testing of whole blood (WB) collections at an academic hospital-based donor center in the eastern United States. All WB donations from 2011 to 2023 which demonstrated reactive syphilis screening (Beckman Coulter PK TP Microhemagglutination) with negative confirmatory testing (CAPTIA Syphilis (T. pallidum)-G) were evaluated. Reactivity rates by year and season of donation were compared using unpaired t-tests. RESULTS: A total of 109 WB donations from 86 unique donors who donated from 2011 to 2023 screened reactive for syphilis with negative confirmatory testing. The unconfirmed syphilis reactivity rate increased from 2018 to 2023 (mean: 0.360%) compared to 2011-2017 (mean: 0.071%, p < .05). An autumnal peak in unconfirmed reactives was observed. CONCLUSION: The unconfirmed syphilis reactivity rate among WB donors at our institution increased markedly since 2017 compared to the 7 years prior and doubled from 2020 to 2021. No testing assay changes explain these results. The autumnal peak in unconfirmed reactives suggests a possible environmental trigger such as viral infection or vaccination.

CD34+ cell yield among healthy donors: Large-scale model development and validation.

BACKGROUND: Successful engraftment in hematopoietic stem cell transplantation necessitates the collection of an adequate dose of CD34+ cells. Thus, the precise estimation of CD34+ cells harvested via apheresis is critical. Current CD34+ cell yield prediction models have limited reproducibility. This study aims to develop a more reliable and universally applicable model by utilizing a large dataset, enhancing yield predictions, optimizing the collection process, and improving clinical outcomes. MATERIALS AND METHODS: A secondary analysis was conducted using the Center for International Blood and Marrow Transplant Research database, involving data from over 17 000 healthy donors who underwent filgrastim-mobilized hematopoietic progenitor cell apheresis. Linear regression, gradient boosting regressor, and logistic regression classification models were employed to predict CD34+ cell yield. RESULTS: Key predictors identified include pre-apheresis CD34+ cell count, weight, age, sex, and blood volume processed. The linear regression model achieved a coefficient of determination (R2) value of 0.66 and a correlation coefficient (r) of 0.81. The gradient boosting regressor model demonstrated marginally improved results with an R2 value of 0.67 and an r value of 0.82. The logistic regression classification model achieved a predictive accuracy of 96% at the 200 × 106 CD34+ cell count threshold. At thresholds of 400, 600, 800, and 1000 × 106 CD34+ cell count, the accuracies were 88%, 83%, 83%, and 88%, respectively. The model demonstrated a high area under the receiver operator curve scores ranging from 0.90 to 0.93. CONCLUSION: This study introduces advanced predictive models for estimating CD34+ cell yield, with the logistic regression classification model demonstrating remarkable accuracy and practical utility.

Consideration for alpha-gal syndrome in two critically ill persons with group O blood who received group B plasma.

BACKGROUND: The U.S. Centers for Disease Control and Prevention (CDC) has reported increasing rates of alpha-gal syndrome, an allergic response after meat ingestion (AGS). AGS has been associated with prior exposure to tick bites or other biologics characterized by a life-threatening immunoglobulin E (IgE)-mediated hypersensitivity to galactose-alpha-1,3-galactose (alpha-gal) an oligosaccharide structurally similar to the group B antigen on red blood cells (RBC) found in most non-primate mammalian meat and products derived from these mammals. In 2023, Transfusion reported 3 group O recipients of group B plasma in the Washington, D.C. metropolitan area with no history of meat allergy who had anaphylactic transfusion reactions compatible with AGS. AIMS: We investigated allergic reactions in 2 additional patients who received ABO minor-incompatible blood products at 2 hospitals in the D.C. area during fall 2023. METHODS: For both patients, a medical chart review was performed and IgE levels to alpha-gal were measured. RESULTS: The first patient, a 64-year-old, O-positive patient status post heart transplant with no known allergies, was admitted with acute COVID-19 induced antibody-mediated transplant rejection and placed on extracorporeal membrane oxygenation (ECMO). While undergoing plasma exchange (PLEX) (50% albumin/50% fresh frozen plasma (FFP)), the patient tolerated 2 units of group O FFP and 1 unit of group A FFP before becoming hemodynamically unstable during transfusion of 1 unit of B-positive FFP. PLEX was stopped. The patient later died of sepsis from underlying causes. The second patient, a 57-year-old O-positive man with a history of melanoma and neuro fibromatosis type 1, was undergoing an abdominal resection including transfusion of 3 units of O-positive RBC when he suffered hypotension and ventricular tachycardia requiring intraoperative code after receiving 2 units of group B FFP. Hiveswere noted after resuscitation. The patient had a history of tick bites but no known allergies. He is alive 5 months after the possible allergic event. Both patients had full transfusion reaction evaluations and immunology testing results above the positive cutoff for anti-alpha-gal IgE. DISCUSSION AND CONCLUSION: Two patients with O-positive blood and no known allergies experience danaphyl axis after transfusion with group B FFP. The symptoms cannot definitively be imputed to an allergic transfusion reaction, but the presence of IgE against alpha-gal supports an association. Medicating patients with antihistamines and IV steroids pre-transfusion may prevent allergic reactions. Restricting group B plasma-containing products (plasma, platelets, cryoprecipitate) for patients who experience AGS-like symptoms may be considered.

Granulocyte transfusions in severe aplastic anemia.

Patients with severe aplastic anemia (SAA) are at high risk for morbidity and mortality due to severe infections. We aimed to characterize the role of granulocyte transfusion (GT) in SAA. Primary outcomes were survival from first GT, including overall survival (OS) at last follow up, survival to discharge, and receipt of HSCT. Secondary outcomes included evaluation of clinical response at 7 and 30 days after GT initiation based on a clinical scoring system incorporating microbiological and radiographic response. Twenty-eight SAA patients underwent 30 GT courses with a per-dose median of 1.28 x 109 granulocyte cells/kilogram (range 0.45-4.52 x 109). OS from initial GT to median last follow up (551 days) was 50%, with 39% (11/28) alive at last follow up. Sixty-four percent (18/28) of all patients survived to hospital discharge. Patients with complete, partial, or stable response at 30 days had significantly improved OS compared to non-responders (p=0.0004). Eighty-six percent (18/21) of patients awaiting HSCT during GT underwent transplant and 62% (13/21) survived to post-HSCT discharge. Sex, type of infection, or percentage of days with absolute neutrophil count > 0.2x109/L during GT course were not predictive of survival (p=0.52, p=0.7, p=0.28). Nine of 28 (32%) patients developed new or increased human leukocyte antigen (HLA) alloimmunization during their GT course. GTs in SAA may impact survival in those with improvement or stabilization of their underlying infection. Alloimmunization can occur and OS in this population remains poor, but GTs may be a useful tool to bridge patients to curative treatment with HSCT.

Advancing Understandings of Blood Donation Motivation and Behavior.

In this review, we provide critical analysis of social science research into blood donation motivation and behavior. We first share an understanding of the existing literature and recommendations for future research collectively developed by members of the Working Group on Blood Donors and the Supply: Diversifying while Maintaining the Donor Pool, Donor Selection, and Optimizing Blood Availability and Safety, as part of the National Heart, Lung, and Blood Institute's 2022 State of the Science in Transfusion Medicine symposium. Then, rather than aim for a comprehensive treatment, we review 4 newer manuscripts that exemplify aspects of the group's recommendations and report results from countries where the blood supply is based on voluntary, nonremunerated donations. From the substantial existing literature, we selected: (1) a study that employed motivational interviewing techniques, thematic analysis, and surveys to link donation motivations and barriers reported by diverse young donors in the United States to actual donation behavior over a year of subsequent eligibility; (2) a survey regarding donation motivations and barriers and monetary amounts associated with willingness to participate in whole blood, plasma, or platelet collection; (3) a survey-based assessment of various emotional states reported by donors at 2 time points during donation and the relationship between emotional experience and subsequent vasovagal reactions; and (4) an interpretive discourse analysis of blood collection agency messaging to donors and the public in the beginning of the COVID-19 pandemic. We close by noting several challenges posed by the structure of the United States blood system and the current funding environment to conducting rigorous research and translating findings into practice.

Increased serum pro-B-type natriuretic peptide in hematopoietic progenitor cell donors stimulated with G-CSF.

Hematopoietic stem cells (HPCs) donors mobilized by granulocyte-colony-stimulating factor (G-CSF) can develop various signs and symptoms. proBNP (pro-B-type natriuretic peptide) is a serum marker of heart failure. A donor who developed severe adverse reactions after G-CSF mobilization was found to have high serum proBNP levels. We followed additional donors who received identical mobilization regimen to investigate the prevalence of this phenomenon. Eighteen healthy donors underwent a mobilization regimen of 10 µg/Kg G-CSF daily for 5 days prior to allogeneic HPC collection using Spectra Optia between January 2016 and February 2017 were included in this study. Serum proBNP levels were measured before and after G-CSF stimulation and immediately after apheresis. Apheresis collection parameters and other laboratory results were also reviewed. The majority of donors (86.7%) had post-G-CSF elevation of serum proBNP. Seven of those had elevated proBNP above upper normal range (124 pg/ml). The subgroup of donors with normal proBNP is younger (median age of 37 vs 42 years), with majority being male (90.9% vs 28.6%) and with smaller processed blood volume (2.2 vs 3 × total blood volume). This case series demonstrates an increase of serum proBNP can be common in HPC donors stimulated with 5 days of 10 mcg/kg G-CSF. This is an adverse reaction that has not been described before. The temporary elevation of proBNP in these donors is not associated with ventricular dysfunction of the heart. The risk factors for marked elevation of proBNP post-G-CSF should be further investigated.