Effect of Plasma Unit Weight and Donor Sex on Post-Donation Citrate Level: An Experimental Study on Plasmapheresis Donors.

Introduction: Plasmapheresis donation is considered safe and well tolerated, although long-term effects need to be clarified. The volumes of anticoagulant (ACD-A) used are variable and depend primarily on hematocrit (HCT), total blood processed, amount of plasma collected, and donor characteristics. To elucidate the effect of the plasma unit weight setting on plasmapheresis efficiency and ACD-A distribution, we enrolled male donors undergoing a controlled apheresis process donating 700 g and 720 g in two different sessions. In parallel, we investigated a possible effect of sex, recruiting women donating 700 g of plasma. Methods: The study was conducted on men donating 720 g and (12 months later) 700 g of plasma, and on women donating 700 g of plasma. The main outcomes were pre-/post-donation delta (Δ) citrate concentration in donor plasma and ACD-A reinfused to the donor. Information concerning the annual check-up and the procedure was also collected. Intergroup comparisons (men donating 720 g vs. men donating 700 g and men vs. women both donating 700 g) and intragroup associations with donor and procedural characteristics were reported. Results: With the procedure set at 720 g, the machine processed around 44 mL more whole blood to collect 20 g more plasma, and 720 g donors received around 12 mL more anticoagulant than 700 g donors. Accordingly, Δ citrate concentration was 1.5 times higher (12 µm), with a greater variability observed for 720 g donations. Citrate concentration in the plasma unit was lower in the 720 g group, although not significantly. Comparing outcomes between women and men donating 700 g, we observed higher (and highly variable) Δ citrate and reinfused ACD-A in women, accompanied by lower anticoagulant levels in the unit. Increased Δ citrate is inversely associated with HCT and age in men and with HCT and triglycerides in women. Reinfused ACD-A correlates with HCT in women but not in men. Conclusion: Unit weight setting and sex influence an ACD-A shift from the estimated values toward an increased reinfusion to donor. In parallel, we observed an impact of age and sex on post-donation citrate metabolism. Altogether, these elements should be taken into account for the development of tailored approaches aimed at maintaining similar safety profiles for all donors using different plasmapheresis settings.

Cryopreservation affects platelet macromolecular composition over time after thawing and differently impacts on cancer cells behavior in vitro.

Cryopreservation affects platelets' function, questioning their use for cancer patients. We aimed to investigate the biochemical events that occur over time after thawing to optimize transfusion timing and evaluate the effect of platelet supernatants on tumor cell behavior in vitro. We compared fresh (Fresh-PLT) with Cryopreserved platelets (Cryo-PLT) at 1 h, 3 h and 6 h after thawing. MCF-7 and HL-60 cells were cultured with Fresh- or 1 h Cryo-PLT supernatants to investigate cell proliferation, migration, and PLT-cell adhesion. We noticed a significant impairment of hemostatic activity accompanied by a post-thaw decrease of CD42b+ , which identifies the CD62P--population. FTIR spectroscopy revealed a decrease in the total protein content together with changes in their conformational structure, which identified two sub-groups: 1) Fresh and 1 h Cryo-PLT; 2) 3 h and 6 h cryo-PLT. Extracellular vesicle shedding and phosphatidylserine externalization (PS) increased after thawing. Cryo-PLT supernatants inhibited cell proliferation, impaired MCF-7 cell migration, and reduced ability to adhere to tumor cells. Within the first 3 hours after thawing, irreversible alterations of biomolecular structure occur in Cryo-PLT. Nevertheless, Cryo-PLT should be considered safe for the transfusion of cancer patients because of their insufficient capability to promote cancer cell proliferation, adhesion, or migration.

What is the context? Transfusion of Fresh platelets (Fresh-PLT) with prophylaxis purposes is common in onco-hematological patients.Cryopreservation is an alternative storage method that allows to extend platelet component shelf life and build supplies usable in case of emergency.It is well established that cryopreservation affects platelet function questioning their use in onco-hematological patients.It is still unknown how platelet impairment, induced by cryopreservation, occurs over time after thawing, nor how the by-products of PLT deterioration may impact on cancer cell behavior.What is new? In this study, we deeply characterized the functional and morphological changes induced by cryopreservation on platelets by comparing Fresh-PLT with Cryo-PLT at 1 h, 3 h and 6 h after thawing. Afterwards, we evaluated the effect of PLT supernatants on cancer cell behavior in vitro.The data presented show that within 3 hours after thawing Cryo-PLT undergo to irreversible macromolecular changes accompanied by increase of peroxidation processes and protein misfolding.After thawing the clot formation is reduced but still supported at all-time points measured, combined with unchanged phosphatidylserine expression and extracellular vesicles release over time.Cryo-PLT supernatants do not sustain proliferation and migration of cancer cells.WHAT is the impact? Cryo-PLT may be considered a precious back-up product to be used during periods of Fresh-PLT shortage to prevent bleeding in non-hemorrhagic patients.It is desirable to make it logistically feasible to transfuse cryopreserved platelets within 1 hour of thawing to maintain the platelets in their best performing condition.

A cohort study on the biochemical and haematological parameters of Italian blood donors as possible risk factors of COVID-19 infection and severe disease in the pre- and post-Omicron period.

To investigate the association between biochemical and blood parameters collected before the pandemic in a large cohort of Italian blood donors with the risk of infection and severe disease. We also focused on the differences between the pre- and post-Omicron spread in Italy (i.e., pre- and post-January 01, 2022) on the observed associations. We conducted an observational cohort study on 13750 blood donors was conducted using data archived up to 5 years before the pandemic. A t-test or chi-squared test was used to compare differences between groups. Hazard ratios with 95% confidence intervals for SARS-CoV-2 infection and severe disease were estimated using Cox proportional hazards models. Subgroup analyses stratified by sex, age and epidemic phase of first infection (pre- and post-Omicron spread) were examined. We confirmed a protective effect of groups B and O, while groups A and AB had a higher likelihood of infection and severe disease. However, these associations were only significant in the pre-Omicron period. We found an opposite behavior after Omicron spread, with the O phenotype having a higher probability of infection. When stratified by variant, A antigen appeared to protect against Omicron infection, whereas it was associated with an increased risk of infection by earlier variants. We were able to stratify for the SARS CoV-2 dominant variant, which revealed a causal association between blood group and probability of infection, as evidenced by the strong effect modification observed between the pre- and post-Omicron spread. The mechanism by which group A acts on the probability of infection should consider this strong effect modification.

Reduction of EpCAM-Positive Cells from a Cell Salvage Product Is Achieved by Leucocyte Depletion Filters Alone.

Intraoperative cell salvage reduces the need for allogeneic blood transfusion in complex cancer surgery, but concerns about the possibility of it re-infusing cancer cells have hindered its application in oncology. We monitored the presence of cancer cells on patient-salvaged blood by means of flow cytometry; next, we simulated cell salvage, followed by leucodepletion and irradiation on blood contaminated with a known amount of EpCAM-expressing cancer cells, assessing also residual cancer cell proliferation as well as the quality of salvaged red blood cell concentrates (RBCs). We observed a significant reduction of EpCAM-positive cells in both cancer patients and contaminated blood, which was comparable to the negative control after leucodepletion. The washing, leucodepletion and leucodepletion plus irradiation steps of cell salvage were shown to preserve the quality of RBCs in terms of haemolysis, membrane integrity and osmotic resistance. Finally, cancer cells isolated from salvaged blood lose their ability to proliferate. Our results confirm that cell salvage does not concentrate proliferating cancer cells, and that leucodepletion allows for the reduction of residual nucleated cells, making irradiation unnecessary. Our study gathers pieces of evidence on the feasibility of this procedure in complex cancer surgery. Nevertheless, it highlights the necessity of finding a definitive consensus through prospective trials.

Mother-newborn ABO group discrepancy caused by a rare BW.17 variant.

Several ABO gene mutations are known to determine rare subgroups: these ABO variants are often responsible for weak or null phenotypes and may cause an incorrect determination of the serotype. Here we describe for the first time the phenotypic discrepancy of a rare B allele within the same Caucasian family that depends on the co-inheritance with A or H antigen. Blood samples from newborns, mothers, and grandmothers were analysed through routine serotype and genotype testing. Blood compatibility test was performed for red blood cells or serum of the grandmother. ABO exons were investigated through PCR and sanger sequencing. According to serology, the phenotype of the mother was AB, while it was O for the newborn. Genotype analysis confirmed that the mother was AB, while the newborn was found to be B. Sanger sequencing revealed the presence of a rare mutation in both individuals (784 G>A, D262N), corresponding to the ABO*BW.17 allele. The grandmother was found to have the same genotype/serotype of the newborn. Crossmatch testing suggested that subjects with this genotype/serotype might be considered O donors and recipients.

Platelet-rich Plasma Lysate for Treatment of Eye Surface Diseases.

Various ocular surface diseases are treated with blood-derived eye drops. Their use has been introduced in clinical practice because of their metabolite and growth factor content, which promotes eye surface regeneration. Blood-based eye drops can be prepared from different sources (i.e., whole blood or platelet apheresis donation), as well as with different protocols (e.g., different dilutions and freeze/thaw cycles). This variability hampers the standardization of clinical protocols and, consequently, the evaluation of their clinical efficacy. Detailing and sharing the methodological procedures may contribute to defining common guidelines. Over the last years, allogenic products have been diffusing as an alternative to the autologous treatments since they guarantee higher efficacy standards; among them, the platelet-rich plasma lysate (PRP-L) eye drops are prepared with simple manufacturing procedures. In the transfusion medicine unit at AUSL-IRCCS di Reggio Emilia, Italy, PRP-L is obtained from platelet-apheresis donation. This product is initially diluted to 0.3 x 109 platelets/mL (starting from an average concentration of 1 x 109 platelets/mL) in 0.9% NaCl. Diluted platelets are frozen/thawed and, subsequently, centrifuged to eliminate debris. The final volume is split into 1.45 mL aliquots and stored at -80 °C. Before being dispensed to patients, eye drops are tested for sterility. Patients may store platelet lysates at -15 °C for up to 1 month. The growth factor composition is also assessed from randomly selected aliquots, and the mean values are reported here.