Pilar Solves

Background and Objective: Transfusion support is a cornerstone of care for patients undergoing allogeneic hematopoietic stem cell transplantation (HSCT), yet many aspects of transfusion practice remain controversial due to limited high-quality evidence. Conditioning regimens induce profound cytopenias, making red blood cell (RBC) and platelet (PLT) transfusions essential. Transfusion requirements vary according to transplant modality, with cord blood and haploidentical transplants associated with higher needs. ABO incompatibility, present in up to 50% of transplantation procedures, is not a contraindication but may lead to immunohematological complications such as passenger lymphocyte syndrome and pure red cell aplasia. The objective of this review is to summarise the current guidelines on transfusion management for HSCT patients focusing on evidence GAPs and unresolved issues. Methods: PubMed database was used to carry out the literature search. Search terms used were: “allogeneic hematopoietic stem cell transplantation, blood transfusion, platelet transfusion, transfusion guidelines”, from 2000 to March, 2026. All articles were reviewed and those references that did not include the term allogeneic stem cell transplantation or hematological patients were discarded. Key Content and Findings: Transfusion strategies in ABO-incompatible HSCT must account for the dynamic transition from recipient to donor blood group, requiring careful selection of RBCs, PLTs, and plasma during different transplant phases. While general recommendations exist, PLT transfusion remains particularly challenging because of limited product availability and weak evidence supporting ABO-based selection. Prophylactic PLT transfusion at a threshold of 10×10⁹/L is currently recommended for stable patients, with higher thresholds for bleeding risk or invasive procedures. Restrictive RBC transfusion strategies (hemoglobin Conclusions: Although blood component transfusion is a critical supportive therapy in HSCT, some transfusion decisions rely on low-quality evidence, resulting in wide variability in clinical practice among centers.

Background: Platelet transfusion can be life-saving in some situations, but, if unnecessary, it puts the patients at risk and increases health system costs. Previous reports of audits performed on platelet transfusion practice in hospitals from different countries show a low adherence of physicians to the current recommendation. The objective of this article is to describe our patient blood management strategy to improve platelet transfusion practice of hematologic inpatients and outpatients, focusing on the impact on platelet transfusion activity and appropriateness rate. Methods: We developed a specific platelet transfusion guideline for hematological patients at our hospital. Platelet transfusion activity was audited after implementing the guide in mid-2024 and mid-2025, and these data were compared to the previous audits performed before the intervention. We also reviewed the platelet transfusion activity and adverse effects related to from 2021 to 2024. Results: Audit 1 reviewed 128 inpatients and 49 outpatients transfused from March 2022 to September 2023. Audit 2 studied 130 inpatients and 45 outpatients requiring platelet transfusion from March 2025 to July 2025. Annual platelet transfusions decreased from 8028 before intervention to 6880 in 2024 (14% decrease). In the hematological area, where the intervention has been made, the reduction in platelet transfusions was of 15.6% in hospitalized patients and 34.5% in outpatients as compared to 2023 (p < 0.001). The platelet supply decreased from 8407 in 2023 to 7138 in 2024. Adverse events related to PLT transfusion occurred in 51 patients in 2023 and 35 patients in 2024. Conclusions: Implementing patient blood management strategies focused on platelets led to a more rational and standardized use of platelet transfusions and decreased transfusion burden. Each organization should establish thresholds for platelet transfusion based on available evidence and guidelines, and also audit adherence to guidelines. In view of the scarce available evidence, research on platelet transfusion practice is mandatory.

Background. Umbilical cord blood donations has increased worldwide, raising concerns about maternal and neonatal safety. This study aims to evaluate its impact on postpartum hemorrhage, transfusion requirements, and duration of delivery, placental retention, and neonatal outcomes. Materials and methods. A prospective observational study was conducted at Hospital Universitario y Politécnico La Fe (Valencia, Spain) between November 2009 and February 2015. Eligible participants were adult women with ≥ 37 weeks´ gestation, low obstetric risk, and single spontaneous labor. Cord blood donation was voluntary. Maternal variables analyzed included blood loss, hemoglobin and hematocrit decline, need for transfusion, length of labor, and placental retention. Neonatal variables included umbilical pH and Apgar test. Results. A total of 144 women were included (73 donors). Donors had a longer interval from delivery to the end of suturing (30.69±16.37 vs. 22.91±12.19 minutes; p<0.001), and of delivery (11.11±10.05 vs. 7.99±5.92 minutes; p=0.10), No significant differences were observed in hemodynamic variables, placental retention, or manual placental extraction. There were no significant differences in blood loss or need for transfusion, although the two transfusions in the donor group were associated with placental retention requiring manual placental extraction and uterine atony. Neonatal outcomes did not differ between groups. Conclusions. Umbilical cord blood donation does not increase maternal risk of transfusion, duration of delivery, or manual retention or removal of the placenta, and it does not adversely affect neonatal outcomes. Fundamento. La donación de sangre de cordón umbilical ha incrementado globalmente, siendo fundamental garantizar la seguridad materna y neonatal. Este estudio evalúa su relación con hemorragia postparto, transfusiones, duración del alumbramiento, retención placentaria y estado neonatal. Material y métodos. Estudio de cohortes prospectivo realizado en el Hospital Universitario y Politécnico La Fe (Valencia, España) entre 2009 y 2015. Se incluyeron gestantes adultas de ≥ 37 semanas, bajo riesgo obstétrico y parto único espontáneo; la donación fue voluntaria. Se analizaron variables maternas (incluyendo pérdida sanguínea, descenso de hemoglobina y hematocrito, transfusiones, duración del alumbramiento, retención placentaria) y neonatales (pH umbilical y test de Apgar). Resultados. Participaron 144 mujeres (73 donantes). La duración desde el parto hasta el final de la sutura (30,69±16,37 vs 22,91±12,19 minutos; p<0,001) y del alumbramiento (11,11±10,05 vs 7,99±5,92 minutos; p=0,10) fue mayor en las donantes. No hubo diferencias significativas en retención placentaria, extracción manual de la placenta, ni mayor pérdida sanguínea ni transfusiones. Las dos transfusiones en el grupo de donantes se asociaron a retención placentaria con extracción manual de la placenta y atonía uterina. No se observaron otras diferencias entre los grupos. Conclusiones. La donación de sangre del cordón umbilical no incrementa la necesidad de transfusiones sanguíneas, la duración del alumbramiento, la retención o extracción manual de la placenta, y no afecta al estado neonatal.

Background/Objectived: Daratumumab is an anti-CD38 monoclonal antibody used in the treatment of multiple myeloma. Its use interferes with the indirect antiglobulin test (IAT). Treatment of reagent red blood cells (RBCs) with dithiothreitol (DTT) is one of the most validated techniques to resolve this interference. The objective of this study is to evaluate the rate of alloimmunization in transfused patients receiving daratumumab and the occurrence of hemolytic transfusion reactions. Materials and Methods: We conducted a single-center, retrospective, descriptive analysis of all patients treated with daratumumab at our institution from October 2016 to April 2024. For daratumumab-treated patients requiring RBC transfusions, an IAT with DTT-pretreated RBCs (DTT-IAT) was performed using the automated Orthovision system. Transfusion was administered only with a previous negative DTT-IAT while respecting Rh and Kell phenotyping. We assessed the transfusion profile of our patient cohort, including their rates of alloimmunization before and after daratumumab initiation, as well as the incidence of hemolytic complications. Additionally, a literature review was performed on reported alloimmunization rates in daratumumab-treated patients. Results: Among all patients, 106 received RBC and/or platelet transfusions after starting daratumumab. Four had known pre-existing alloantibodies. None developed new alloantibodies or experienced hemolytic complications while receiving anti-CD38 therapy. There were four cases of false-positive DTT-IAT due to residual drug interference or technical variability, in which no alloantibodies or adverse transfusion reactions were detected. Conclusions: Patients receiving daratumumab exhibit a low risk of alloimmunization. This may be partly explained by adherence to Rh and Kell phenotyping and daratumumab’s immunosuppressive effects on alloantibody production. These results support the conclusion that an extended red blood cell phenotype or genotype before starting daratumumab could be omitted if a fast and reliable technique for pretransfusion testing (such as automated DTT-IAT) is available 24 h.

This study assessed 552 allogeneic hematopoietic cell transplantation (HCT) recipients with posttransplant cyclophosphamide (PTCy) to evaluate the incidence, characteristics, risk factors, and impact of early posttransplant cytokine release syndrome (CRS) on outcomes. The cohort included 36% matched sibling donors (MSD), 34% matched unrelated donors (MUD), 27% haploidentical donors, and 4% mismatched unrelated donors (MMUD). CRS was observed in 182 patients, with the highest incidence in haploidentical transplants (80%) compared to MMUD (32%), MUD (23%), and MSD (8%). Most CRS cases were mild, with 93% classified as grade 1 and 6% as grade 2, with only one severe case of grade 3. In haploidentical transplants, CRS was linked to a lower risk of severe chronic graft-versus-host disease (GVHD) and non-relapse mortality (NRM), leading to improved overall survival. In contrast, among HLA-matched recipients (MSD and MUD), there were no significant differences in outcomes between those with or without CRS. However, subgroup analysis revealed that CRS in patients with myeloid malignancies, including acute myeloid leukemia, myelodysplastic syndromes, and myeloproliferative neoplasms, was associated with a reduced relapse rate, improving survival outcomes. In conclusion, while CRS is typically mild and short-lived, it significantly impacts survival, particularly in haploidentical transplants and HLA-matched patients with myeloid malignancies.