Post-thaw CD34+ cell recovery likely degraded under extreme graft platelet concentrations.

Impaired post-thaw CD34 cell (postCD34) viability in autologous haematopoietic stem cell transplant (ASCT) could indicate delayed engraftment where multiple factors might complicate the relationship. Despite of a couple of unconfirmed reports of a negative correlation of platelet concentration with postCD34 viability, how platelets might be involved in the relationship is largely unknown. Therefore, this question was addressed in this retrospective study of 82 ASCT patients with a total of 150 collections of peripheral blood stem cells in New Zealand. A significant negative correction between platelet concentration and postCD34 recovery (r = -0.18, p = 0.028) was observed overall, but upon further analysis only confirmed in the subset with graft platelets 1500-2000 ×109/L. Importantly, the postCD34 recovery was clearly reduced in the subgroups with either the lowest or the highest platelet concentration. The lowest subgroup was enriched with collections from patients with Hodgkin or non-Hodgkin lymphoma, whereas the highest subgroup from patients with multiple myeloma, both with clearly male preponderance. We hypothesized that graft platelet concentrations probably indicated CD34 cell state (e.g. cell cycle and cell adhesion highly related to platelet functions) that sustained when platelet concentrations were within a niche range but went out of kilter otherwise.

Novel risk patterns of vasovagal reactions in NZ blood donations complicated by COVID-19 restrictions.

Introduction: Vasovagal reactions (VVRs) are common but complex donor adverse reactions (DAEs) in blood donations. VVRs have been extensively studied with a multitude of risk factors identified including young age, female gender and first-time donor status. How they may interplay remains obscure. Methods: A total of 1,984,116 blood donations and 27,952 immediate VVRs (iVVRs) and 1,365 delayed VVRs (dVVRs) reported between 2011 and 2021 in NZ were used in multivariate logistic regression analyses each concerning donations with iVVRs as cases and those free of DAEs as controls. For each analysis stepwise selection was used to identify the best model and risk factors carrying significant main effects and/or interactions. Identified interactions informed further in-depth regression analyses to dissect iVVR risk patterns. Results: Over 95% of VVRs were iVVRs that had lower female preponderance and deferrals than dVVRs. iVVRs had a school seasonal pattern in whole blood donations driven by first-time donors from schools/colleges, and interactions between gender and age group differentiating the first-time from repeat donations. Subsequent regression analyses identified the known and novel risk factors of year and mobile collection sites and their interactions. iVVR rates were roundly elevated in 2020 and 2021 probably because of COVID-19 restrictions like facemask wearing. Exclusion of the 2020 and 2021 data removed the interactions with year, but confirmed interactions of gender with mobile collection sites (p = 6.2e-07) in first-time donations only and with age group in repeat donations only (p < 2.2e-16), together indicating young female donors at the highest risk of iVVRs. Our results also revealed that donation policy changes contributed to the year effects; donors had a lower iVVR risk at mobile sites than well-medicalized donation centers probably because of under-reporting. Conclusion: Modeling statistical interactions is valuable in identifying odds and revealing novel iVVR risk patterns and insights into blood donations.

The granulocytes in neutropenia 1 (GIN 1) study: a safety study of granulocytes collected from whole blood and stored in additive solution and plasma.

OBJECTIVE/AIM: To evaluate the safety of transfusing pooled, whole blood-derived granulocytes in additive solution and plasma (GASP) in 30 recipients. BACKGROUND: Demand for granulocytes in England has increased five-fold. With the advantages of reduced red cell, plasma and overall volume, GASP maintains function in vitro. METHODS AND MATERIALS: Observations were recorded prior to and post transfusion. Increments were recorded at 1 h and the following morning. Leucocyte antibody screening was undertaken prior to and at 1-6 months following transfusion. RESULTS: Thirty patients aged between 8 months and 68 years received 221 GASP in 148 transfusion episodes. GASP contained an average of 1.0 × 10(10) granulocytes in 207 mL. Adults usually received two packs and children 10-20 mL kg(-1). Children and adults received a median [interquartile range (IQR)] dose of 12.5 (9.1-25.3) and 19.7 (12.0-25.8) × 10(9) granulocytes per transfusion, respectively. There was one episode of transfusion-associated circulatory overload (TACO) in a patient with chronic cardiac failure following 600 mL of unpooled granulocytes, other fluids and one GASP. New leucocyte alloimmunisation occurred in 3/30 recipients 10%. No other significant reactions were reported. Median peripheral blood neutrophil increments at 1 h post transfusion were 0.06 (IQR, 0.01-0.17) in children and (0.03) (IQR, 0-0.16) in adults. CONCLUSION: GASP has a similar safety profile to other sources of granulocytes for patients with refractory infection or in need of secondary prophylactic transfusion. Further studies are required to clarify the role of GASP in the treatment of neutropenic patients.