Red blood cell transfusion in surgical cancer patients: Targets, risks, mechanistic understanding and further therapeutic opportunities

N6-methyl-2'-deoxyadenosine promotes self-renewal of BFU-E progenitor in erythropoiesis

Red blood cells supply the oxygen required for all human cells and are in demand for emerging blood-loss therapy. Here we identified N6-methyl-2'-deoxyadenosine (6mdA) as an agonist that promotes the hyperproliferation of burst-forming unit erythroid (BFU-E) progenitor cells. In addition, 6mdA represses the apoptosis of erythroid progenitor cells (EPCs). Combined use of with SCF and EPO enabled cultures of isolated BFU-E to be expanded up to 5,000-fold. Transcriptome analysis showed that 6mdA upregulates the expression of the EPC-associated factors c-Kit, Myb, and Gata2 and downregulates that of the erythroid maturation-related transcription factors Gata1, Spi1, and Klf1. Mechanistic studies suggested that 6mdA enhances and prolongs the activation of erythropoiesis-associated master gene c-Kit and its downstream signaling, leading to expansion and accumulation of EPCs. Collectively, we demonstrate that 6mdA can efficiently stimulate the EPC hyperproliferation and provide a new regenerative medicine recipe to improve ex vivo generation of red blood cells.

How do I reduce variation in red blood cell transfusion practices in a large integrated health care system?

BACKGROUND

Reducing variation in transfusion practices can prevent unwarranted transfusions, an outcome that improves quality of care and patient safety, while lowering costs and eliminating waste of blood. We developed and assessed a system-wide initiative to reduce variation in red blood cell (RBC) transfusion in terms of both transfusion utilization and the number of units transfused.

INTERVENTION DESIGN AND METHODS

Our initiative combined a single-unit default order for RBC transfusion in hemodynamically stable, non-bleeding patients with a "Why Give 2 When 1 Will Do?" Choosing Wisely campaign, while also promoting a restrictive hemoglobin threshold (Hb <7 g/dl). This multimodal intervention was implemented across an academic medical center (AMC) with over 950 beds and 10 community hospitals.

RESULTS

Between our baseline (CY 2020) and intervention period (CY 2021), single-unit orders increased from 57% to 70% of all RBC transfusion orders (p < .001). The greatest change in ordering practices was at community hospitals, where single-unit orders increased from 46% to 65% (p < .001). Over the same time period, the system-wide mean (SD) Hb result prior to transfusion fell from 7.3 (0.05) to 7.2 g/dl (0.04) (p < .05). We estimate this effort saved over 4000 units of blood and over $4 million in direct and indirect costs in its first year.

DISCUSSION

By combining a single-unit default setting in the RBC order with a restrictive hemoglobin threshold, we significantly reduced variation in ordering practices. This effort demonstrates the value of single-unit policies and "nudges" in system-wide patient blood management initiatives.

Perioperative Blood Transfusion Is Dose-Dependently Associated with Cancer Recurrence and Mortality after Head and Neck Cancer Surgery

BACKGROUND

The association between perioperative blood transfusion and cancer prognosis in patients with head and neck cancer (HNC) receiving surgery remains controversial.

METHODS

We designed a retrospective observational study of patients with HNC undergoing tumor resection surgery from 2014 to 2017 and followed them up until June 2020. An inverse probability of treatment weighting (IPTW) was applied to balance baseline patient characteristics in the exposed and unexposed groups. COX regression was used for the evaluation of tumor recurrence and overall survival.

RESULTS

A total of 683 patients were included; 192 of them (28.1%) received perioperative packed RBC transfusion. Perioperative blood transfusion was significantly associated with HNC recurrence (IPTW adjusted HR: 1.37, 95% CI: 1.1-1.7, p = 0.006) and all-cause mortality (IPTW adjusted HR: 1.37, 95% CI: 1.07-1.74, p = 0.011). Otherwise, there was an increased association with cancer recurrence in a dose-dependent manner.

CONCLUSION

Perioperative transfusion was associated with cancer recurrence and mortality after HNC tumor surgery.

Intraoperative autologous transfusion and oncologic outcomes in liver transplantation for hepatocellular carcinoma: a propensity matched analysis

BACKGROUND

Intraoperative autologous transfusion (IAT) of salvaged blood is a common method of resuscitation during liver transplantation (LT), however concern for recurrence in recipients with hepatocellular carcinoma (HCC) has limited widespread adoption.

METHODS

A review of patients undergoing LT for HCC between 2008 and 2018 was performed. Clinicopathologic and intraoperative characteristics associated with inferior recurrence-free (RFS) and overall survival (OS) were identified using Kaplan-Meier analysis and uni-/multi-variable Cox proportional hazards modeling. Propensity matching was utilized to derive clinicopathologically similar groups for subgroup analysis.

RESULTS

One-hundred-eighty-six patients were identified with a median follow up of 65 months. Transplant recipients receiving IAT (n = 131, 70%) also had higher allogenic transfusions (median 5 versus 0 units, P < 0.001). There were 14 recurrences and 46 deaths, yielding an estimated 10-year RFS and OS of 89% and 67%, respectively. IAT was not associated with RFS (HR 0.89/liter, P = 0.60), or OS (HR 0.98/liter, P = 0.83) pre-matching, or with RFS (HR 0.97/liter, P = 0.92) or OS (HR 1.04/liter, P = 0.77) in the matched cohort (n = 49 per group).

CONCLUSION

IAT during LT for HCC is not associated with adverse oncologic outcomes. Use of IAT should be encouraged to minimize the volume of allogenic transfusion in patients undergoing LT for HCC.

Updates on enhanced recovery after surgery for radical cystectomy

Enhanced Recovery after Surgery (ERAS) is a multimodal pathway that provides evidence-based guidance for improving perioperative care and outcomes in patients undergoing surgery. In 2013, the ERAS society released its original guidelines for radical cystectomy (RC) for bladder cancer (BC), adopting much of its supporting data from colorectal literature. In the last decade, growing interest in ERAS has increased RC-specific ERAS research, including prospective randomized controlled trials (RCTs). Collective data suggest ERAS contributes to improved complication rates, decreased hospital length-of-stay, and/or time to bowel recovery. Various institutions have adopted modified versions of the ERAS pathway, yet there remains a lack of consensus on the efficacy of specific ERAS items and standardization of the protocol. In this review, we summarize updated evidence and practice patterns of ERAS pathways for RC since the introduction of the original 2013 guidelines. Novel target interventions, including use of immunonutrition, prehabilitation, alvimopan, and methods of local analgesia are reviewed. Finally, we discuss barriers to implementing and future steps in advancing the ERAS movement.

Transfusion‑related immunomodulation in patients with cancer: Focus on the impact of extracellular vesicles from stored red blood cells (Review)

Red blood cell (RBC) transfusions may have a negative impact on the prognosis of patients with cancer, where transfusion‑related immunomodulation (TRIM) may be a significant contributing factor. A number of components have been indicated to be associated with TRIM. Among these, the impact of extracellular vesicles (EVs) has been garnering increasing attention from researchers. EVs are defined as nano‑scale, cell‑derived vesicles that carry a variety of bioactive molecules, including proteins, nucleic acids and lipids, to mediate cell‑to‑cell communication and exert immunoregulatory functions. RBCs in storage constitutively secrete EVs, which serve an important role in TRIM in patients with cancer receiving a blood transfusion. Therefore, the present review aimed to first summarize the available information on the biogenesis and characterization of EVs. Subsequently, the possible mechanisms of TRIM in patients with cancer and the impact of EVs on TRIM were discussed, aiming to provide an outlook for future studies, specifically for formulating recommendations for managing patients with cancer receiving RBC transfusions.

Leukoreduction makes a difference: A pair proteomics study of extracellular vesicles in red blood cell units

Prestorage filtration of blood to remove contaminating donor leukocytes and platelets has substantially increased the safety level of transfusion therapy. We have previously shown that leukoreduction has a mitigating effect on the storage lesion profile by lowering the extent of hemolysis and of RBC aging and removal phenotypes, including surface signaling and microvesiculation. Even though protein composition may determine the fate of EVs in the recipient, the probable effect of leukoreduction on the EV proteome has been scarcely investigated. In the present paired study, we characterized the proteome of EVs released in prestorage leukoreduced (L) and nonleukoreduced (N) RBC units prepared from the same donors, by immunoblotting and qualitative proteomics analyses at two storage intervals. Apart from common proteofrms typically associated with the established EV biogenesis mechanisms, the comparative proteomics analyses revealed that both leukoreduction and storage duration affect the complexity of the EV proteome. Membrane and cytoskeleton-related proteins and regulators, metabolic enzymes and plasma proteins exhibited storage duration dependent variation in L- and N-EVs. Specific proteoforms prevailed in each EV group, such as transferrin in L-units or platelet glycoproteins, leukocyte surface molecules, MHC HLA, histones and tetraspanin CD9 in N-units. Of note, several unique proteins have been associated with immunomodulatory, vasoregulatory, coagulatory and anti-bacterial activities or cell adhesion events. The substantial differences between EV composition under the two RBC preparation methods shed light in the underlying EV biogenesis mechanisms and stimuli and may lead to different EV interactions and effects to target cells post transfusion.

Assessment of transient changes in oxygen diffusion of single red blood cells using a microfluidic analytical platform

Red blood cells (RBCs) capability to deliver oxygen (O₂) has been routinely measured by P50. Although this defines the ability of RBCs to carry O₂ under equilibrium states, it cannot determine the efficacy of O₂ delivery in dynamic blood flow. Here, we developed a microfluidic analytical platform (MAP) that isolates single RBCs for assessing transient changes in their O₂ release rate. We found that in vivo (biological) and in vitro (blood storage) aging of RBC could lead to an increase in the O₂ release rate, despite a decrease in P50. Rejuvenation of stored RBCs (Day 42), though increased the P50, failed to restore the O₂ release rate to basal level (Day 0). The temporal dimension provided at the single-cell level by MAP could shed new insights into the dynamics of O₂ delivery in both physiological and pathological conditions.

The opposing roles of the mTOR signaling pathway in different phases of human umbilical cord blood-derived CD34+ cell erythropoiesis

As an indispensable, even lifesaving practice, red blood cell (RBC) transfusion is challenging due to several issues, including supply shortage, immune incompatibility, and blood-borne infections since donated blood is the only source of RBCs. Although large-scale in vitro production of functional RBCs from human stem cells is a promising alternative, so far, no such system has been reported to produce clinically transfusable RBCs due to the poor understanding of mechanisms of human erythropoiesis, which is essential for the optimization of in vitro erythrocyte generation system. We previously reported that inhibition of mammalian target of rapamycin (mTOR) signaling significantly decreased the percentage of erythroid progenitor cells in the bone marrow of wild-type mice. In contrast, rapamycin treatment remarkably improved terminal maturation of erythroblasts and anemia in a mouse model of β-thalassemia. In the present study, we investigated the effect of mTOR inhibition with rapamycin from different time points on human umbilical cord blood-derived CD34⁺ cell erythropoiesis in vitro and the underlying mechanisms. Our data showed that rapamycin treatment significantly suppressed erythroid colony formation in the commitment/proliferation phase of erythropoiesis through inhibition of cell-cycle progression and proliferation. In contrast, during the maturation phase of erythropoiesis, mTOR inhibition dramatically promoted enucleation and mitochondrial clearance by enhancing autophagy. Collectively, our results suggest contrasting roles for mTOR in regulating different phases of human erythropoiesis.

The secrets of human stem cell-derived transfusable RBC for targeted large-scale production and clinical applications: A fresh look into what we need most and lessons to be learned

Blood transfusion, using the safest conventional blood bioproducts, is an irreplaceable part of substitution therapy. It is considered the most essential supportive clinical intervention aimed to restore the health of patients in need. Nevertheless, numerous unresolved problems are still associated with current blood substitution therapy. To alleviate our dependency on blood donors, many investigators have been focusing on the quest for stem cell-derived blood cells in line with major developments in the field of regenerative medicine. The main objective is to provide a safe and highly standardized universal cultured red cell concentrate [CRBC] for all clinical applications, regardless of blood groups. Currently, we are close to overcoming some of the main obstacles in culturing cells. This concise report is a prelude to the immortalized cell lines that are ready for in vivo clinical trials. It is only through the sharing of experimental ideas and knowledge-based strategies that we will be able to achieve such an enormous task and better understand ‘’the one for all concept’’ of CRBCs and their universal usage in all clinical settings.

Iron in the Tumor Microenvironment-Connecting the Dots

Iron metabolism and tumor biology are intimately linked. Iron facilitates the production of oxygen radicals, which may either result in iron-induced cell death, ferroptosis, or contribute to mutagenicity and malignant transformation. Once transformed, malignant cells require high amounts of iron for proliferation. In addition, iron has multiple regulatory effects on the immune system, thus affecting tumor surveillance by immune cells. For these reasons, inconsiderate iron supplementation in cancer patients has the potential of worsening disease course and outcome. On the other hand, chronic immune activation in the setting of malignancy alters systemic iron homeostasis and directs iron fluxes into myeloid cells. While this response aims at withdrawing iron from tumor cells, it may impair the effector functions of tumor-associated macrophages and will result in iron-restricted erythropoiesis and the development of anemia, subsequently. This review summarizes our current knowledge of the interconnections of iron homeostasis with cancer biology, discusses current clinical controversies in the treatment of anemia of cancer and focuses on the potential roles of iron in the solid tumor microenvironment, also speculating on yet unknown molecular mechanisms.

Hepcidin Therapeutics

Hepcidin is a key hormonal regulator of systemic iron homeostasis and its expression is induced by iron or inflammatory stimuli. Genetic defects in iron signaling to hepcidin lead to “hepcidinopathies” ranging from hereditary hemochromatosis to iron-refractory iron deficiency anemia, which are disorders caused by hepcidin deficiency or excess, respectively. Moreover, dysregulation of hepcidin is a pathogenic cofactor in iron-loading anemias with ineffective erythropoiesis and in anemia of inflammation. Experiments with preclinical animal models provided evidence that restoration of appropriate hepcidin levels can be used for the treatment of these conditions. This fueled the rapidly growing field of hepcidin therapeutics. Several hepcidin agonists and antagonists, as well as inducers and inhibitors of hepcidin expression have been identified to date. Some of them were further developed and are currently being evaluated in clinical trials. This review summarizes the state of the art.

Effect of allogeneic blood transfusion on levels of IL-6 and sIL-R2 in peripheral blood of children with acute lymphocytic leukemia

Effect of allogeneic blood transfusion on the expression of interleukin-6 (IL-6) and soluble interleukin-2 receptor (sIL-2R) in peripheral blood of children with acute lymphoblastic leukemia (ALL) was investigated. A total of 91 ALL children admitted to Nanfang Hospital from June 2014 to January 2017 were selected as the study group. Patients were randomly divided into allogeneic blood transfusion group (n=38) and non-transfusion group (n=53). In addition, a total of 64 healthy children were also selected from June 2014 to January 2017 as the control group. Patients in allogeneic blood transfusion group were transfused with red blood cell suspension and machine-collected platelets, while patients in non-transfusion group were not treated with blood transfusion. Peripheral venous blood was collected before and at 4, 8 and 12 weeks after blood transfusion to prepare serum. Serum IL-6 and sIL-2R levels were measured by enzyme-linked immunosorbent assay (ELISA). Before transfusion, serum levels of IL-6 and sIL-2R were significantly lower in the study group than those in control group (p<0.05), and no significant differences in serum levels of IL-6 and sIL-2R were found between the allogeneic blood transfusion and non-transfusion group. After transfusion, serum levels of IL-6 and sIL-2R were stable for 12 weeks in the non-transfusion group, while IL-6 and sIL-2R levels were significantly increased in the allogeneic blood transfusion group. The results showed that serum level of IL-6 and sIL-2R was increased in ALL patients with allogeneic blood transfusion, which resulted in reduced antibody production and decreased cellular immunity. The patients had low immunity, and attention should be paid on the pathogen infection prevention.

Effect of perioperative blood transfusion on prognosis of patients with gastric cancer: a retrospective analysis of a single center database

Background

The association between perioperative blood transfusion and the prognosis of patients with gastric cancer is still unclear.

Methods

A total of 1581 patients with gastric cancer who underwent curative gastrectomy from 2000 to 2008 were evaluated. Perioperative blood transfusion was defined as the transfusion of packed red blood cells within seven days before surgery, during surgery, or within the postoperative hospitalization period. The association between perioperative blood transfusion and prognosis was evaluated using univariate and multivariate Cox regression analyses.

Results

Of 1581 patients, 298 patients (19%) received perioperative blood transfusion. Perioperative blood transfusion correlated with older age (P < 0.001); larger tumor size (P < 0.001); and more advanced stage (P < 0.001). Five-year survival rate was 40% in patients who had perioperative blood transfusion and 55% patients who did not have perioperative blood transfusion, and the difference was statistically significant (P < 0.001). Multivariate analysis showed that perioperative blood transfusion was defined as independent prognostic factor. Perioperative blood transfusion was associated with worse outcomes in patients with stage III (P < 0.001).

Conclusions

Perioperative blood transfusion independently correlated with poorer prognosis in patients with gastric cancer.