Optimal transfusion practices after allogeneic hematopoietic cell transplantation: a systematic scoping review of evidence from randomized controlled trials

From Unit to Dose: A Machine Learning Approach for Precise Prediction of Hemoglobin and Iron Content in Individual Packed Red Blood Cell Units

Transfusion of packed red blood cells (pRBCs) saves lives, but iron overload limits survival of chronically transfused patients. Quality control methods, which involve entering pRBC units and removing them from the blood supply, reveal that hemoglobin (38.5-79.9 g) and heme iron (133.42-276.89 mg) vary substantially between pRBCs. Yet, neither hemoglobin nor iron content can be quantified for individual clinically used pRBCs leading to rules of thumb for pRBC transfusions. Keeping their integrity, the authors seek to predict hemoglobin/iron content of any given pRBC unit applying eight machine learning models on 6,058 pRBCs. Based on thirteen features routinely collected during blood donation, production and quality control testing, the model with best trade-off between performance and complexity in hemoglobin/iron content prediction is identified. Validation of this model in an independent cohort of 2637 pRBCs confirms an adjusted R2 > 0.9 corresponding to a mean absolute prediction error of ≤1.43 g hemoglobin/4.96 mg iron (associated standard deviation: ≤1.13 g hemoglobin/3.92 mg iron). Such unprecedented precise prediction enables reliable pRBC dosing per pharmaceutically active agent, and monitoring iron uptake in patients and individual iron loss in donors. The model is implemented in a free open source web application to facilitate clinical application.

Optimizing Utilization of Blood Products in the Hematologic Malignancy Clinic: Less Is More

PURPOSE

There are no universal guidelines for blood product transfusions in patients with hematologic malignancies (HMs). Excess utilization of platelet and RBC transfusion in patients with HM increases the cost of care and likelihood of adverse events. We aim to decrease the total number of transfused units and multiunit orders of platelets and RBCs in the HM clinic by 25% from March 2020 to December 2020.

METHODS

A multidisciplinary, interprofessional team was formed. Baseline rates of blood product utilization were determined using Qlik Analytic software. Strategies to improve utilization were developed, and three interventions were initiated. Data were collected on monthly intervals. Data for total number of platelet and RBC units ordered, total multiunit orders, average number of units ordered per encounter, and pretransfusion hemoglobin thresholds were collected from May 2019 to December 2020.

RESULTS

Through our Plan-Do-Study-Act cycles from March 2020 to December 2020, the total number of platelet transfusion orders per month decreased from 164 to 98, multiunit platelet orders decreased from 63 to 2, and the average number of platelet transfusions per encounter decreased from 1.62 to 1.03. The total number of RBC transfusion orders decreased from 172 to 141, multiunit RBC orders decreased from 25 to 16, and the average number of RBC transfusions per encounter decreased from 1.21 to 1.18.

CONCLUSION

Implementation of our multidisciplinary interventions led to more appropriate use of blood products in the outpatient setting. Ongoing efforts are underway to continue to improve utilization in the inpatient and outpatient setting.

Extracorporeal membrane oxygenation in children receiving haematopoietic cell transplantation and immune effector cell therapy: an international and multidisciplinary consensus statement

Use of extracorporeal membrane oxygenation (ECMO) in children receiving haematopoietic cell transplantation (HCT) and immune effector cell therapy is controversial and evidence-based guidelines have not been established. Remarkable advancements in HCT and immune effector cell therapies have changed expectations around reversibility of organ dysfunction and survival for affected patients. Herein, members of the Extracorporeal Life Support Organization (ELSO), Pediatric Acute Lung Injury and Sepsis Investigators (PALISI) Network (HCT and cancer immunotherapy subgroup), the Pediatric Diseases Working Party of the European Society for Blood and Marrow Transplantation (EBMT), the supportive care committee of the Pediatric Transplantation and Cellular Therapy Consortium (PTCTC), and the Pediatric Intensive Care Oncology Kids in Europe Research (POKER) group of the European Society of Pediatric and Neonatal Intensive Care (ESPNIC) provide consensus recommendations on the use of ECMO in children receiving HCT and immune effector cell therapy. These are the first international, multidisciplinary consensus-based recommendations on the use of ECMO in this patient population. This Review provides a clinical decision support tool for paediatric haematologists, oncologists, and critical care physicians during the difficult decision-making process of ECMO candidacy and management. These recommendations can represent a base for future research studies focused on ECMO selection criteria and bedside management.

Selective ABO immunoadsorption in hematopoietic stem cell transplantation with major ABO incompatibility

OBJECTIVE

ABO mismatch between donor and recipient occurs in 40% of allogeneic hematopoietic stem cell transplantations (HCT). Different strategies have been described to reduce isohemagglutinins (IHA) before HCT. We describe the effect of selective ABO immunoadsorption (ABO IA) on erythrocyte transfusion rate and the development of post-transplant pure red cell aplasia (ptPRCA).

METHODS

63 patients with major ABO incompatibility were retrospectively analyzed. Nine patients with major ABO incompatibility and high-IHA titer were treated by ABO IA before HCT. We analyzed the need for transfusion and the occurrence of ptPRCA. We compared the outcome with patients treated by other methods to reduce IHA.

RESULTS

In all nine patients treated by ABO IA, IHA decreased in a median four times. PtPRCA occurred in one patient. The median number of transfusions was 8 (range: 0-36) between d0 and d100. In 25 patients with high-IHA titer without treatment or treated by other methods to reduce IHA, the need for transfusions was comparable. No difference in the incidence of ptPRCA was observed.

CONCLUSIONS

Selective ABO IA is a feasible, safe, and effective method to reduce IHA before HCT in major ABO incompatibility. No effect on transfusion rate or ptPRCA compared to other strategies could be observed.

Liberal Versus Restrictive Red Blood Cell Transfusion Thresholds in Hematopoietic Cell Transplantation: A Randomized, Open Label, Phase III, Noninferiority Trial

PURPOSE

Evidence regarding red blood cell (RBC) transfusion practices and their impact on hematopoietic cell transplantation (HCT) outcomes are poorly understood.

PATIENTS AND METHODS

We performed a noninferiority randomized controlled trial in four different centers that evaluated patients with hematologic malignancies requiring HCT who were randomly assigned to either a restrictive (hemoglobin [Hb] threshold < 70 g/L) or liberal (Hb threshold < 90 g/L) RBC transfusion strategy between day 0 and day 100. The noninferiority margin corresponds to a 12% absolute difference between groups in Functional Assessment of Cancer Therapy-Bone Marrow Transplant (FACT-BMT) score relative to baseline. The primary outcome was health-related quality of life (HRQOL) measured by FACT-BMT score at day 100. Additional end points were collected: HRQOL by FACT-BMT score at baseline and at days 7, 14, 28, 60, and 100; transplantation-related mortality; length of hospital stay; intensive care unit admissions; acute graft-versus-host disease; Bearman toxicity score; sinusoidal obstruction syndrome; serious infections; WHO Bleeding Scale; transfusion requirements; and reactions to therapy.

RESULTS

A total of 300 patients were randomly assigned to either restrictive-strategy or liberal-strategy treatment groups between 2011 and 2016 at four Canadian adult HCT centers. After HCT, mean pre-transfusion Hb levels were 70.9 g/L in the restrictive-strategy group and 84.6 g/L in the liberal-strategy group (P < .0001). The number of RBC units transfused was lower in the restrictive-strategy group than in the liberal-strategy group (mean, 2.73 units [standard deviation, 4.81 units] v 5.02 units [standard deviation, 6.13 units]; P = .0004). After adjusting for transfusion type and baseline FACT-BMT score, the restrictive-strategy group had a higher FACT-BMT score at day 100 (difference of 1.6 points; 95% CI, -2.5 to 5.6 points), which was noninferior compared with that of the liberal-strategy group. There were no significant differences in clinical outcomes between the transfusion strategies.

CONCLUSION

In patients undergoing HCT, the use of a restrictive RBC transfusion strategy threshold of 70 g/L was as effective as a threshold of 90 g/L and resulted in similar HRQOL and HCT outcomes with fewer transfusions.

Transfusion support for matched sibling allogeneic hematopoietic stem cell transplantation (1993-2010): factors that predict intensity and time to transfusion independence

BACKGROUND

Patients undergoing allogeneic hematopoietic stem cell transplant require variable, often extensive transfusion support. Identification of factors that predict urgent, intensive, or special needs should improve management of these patients.

STUDY DESIGN AND METHODS

This is a retrospective study of red blood cell (RBC) and platelet transfusion support provided for sequential matched sibling donor allogeneic transplants conducted at the Clinical Center, National Institutes of Health, from 1993 through 2010. Factors potentially important for predicting quantity of RBC and platelet transfusions, and time to transfusion independence through Day 200 following hematopoietic stem cell transplantation were evaluated.

RESULTS

Subjects (n = 800) received 10,591 RBC and 10,199 platelet transfusions. Multivariable analysis demonstrated that the need for RBC pretransplant, CD34+ dose, transplant year, diagnostic category, and ABO match were significantly independently associated with quantity of RBC transfusions during Days 0 through 30. Only pretransplant need for RBCs, CD34+ dose, and transplant year had significance during Days 0 through 100. Similar analyses for quantity of platelet transfusions demonstrated that for both Days 0 through 30 and 0 through 100 significant factors were need for platelet support before transplant, CD34+ dose, transplant year, and transplant regimen. Of note, long term, during Days 101 through 200, only CD34+ dose remained significant for quantity of RBC and platelet transfusions. Analysis of time to transfusion independence demonstrated that patients with ABO major mismatches required longer to achieve freedom from RBC transfusion support compared to identical matches or those with minor mismatches.

CONCLUSION

Patient-specific factors including CD34+ dose and ABO match of the graft should be given particular consideration by transfusion services when planning support of patients receiving allogeneic hematopoietic stem cell transplant.

Platelet Transfusion Refractoriness in Single-Unit Cord Blood Transplantation for Adults: Risk Factors and Clinical Outcomes

Platelet transfusion refractoriness (PTR) is frequently observed after allogeneic hematopoietic cell transplantation (HCT). However, the incidence of and risk factors for PTR, and impact of PTR on transplant outcomes after cord blood transplantation (CBT) have not been fully investigated. We retrospectively analyzed 185 adult patients who received single-unit CBT in our institute. The mean 16-hour corrected count increment (CCI) for the 5840 platelet transfusions was 3.68 × 10⁹/L. Among them, 3196 transfusions (54.7%) were associated with a PTR with 16-hour-CCI <4.5 × 10⁹/L. Results of multivariate analysis indicated that the following factors were significantly associated with decreased platelet transfusion responses: female sex with pregnancy history, male sex, the presence of HLA class I antibody, lower cord blood total nucleated cell dose, lower cord blood CD34⁺ cell dose, 3 locus HLA disparities, body temperature ≥38°C, C-reactive protein ≥10 mg/dL, cytomegalovirus reactivation, use of foscarnet, and use of liposomal amphotericin B. By contrast, graft-versus-host disease prophylaxis including methotrexate, ABO minor mismatch, use of ganciclovir, and use of linezolid were significantly associated with better platelet transfusion responses. PTR had a significant effect on poor neutrophil and platelet recovery, and overall mortality after CBT. These data suggest that early phase PTR may be predictive of engraftment and mortality after single-unit CBT for adults.