Mechanisms and new approaches for the allogeneic blood transfusion-induced immunomodulatory effects

Differential expression of exosomal microRNAs in fresh and senescent apheresis platelet concentrates

Patients have a high risk of suffering adverse reactions after receiving platelet products stored for 5 days. Bioactive exosomes in platelet products can be accumulated during storage, which is associated with adverse reactions. MicroRNAs are one of the critical cargoes in exosomes, which participate in cell differentiation, metabolism, and immunomodulation. This study intends to elucidate and analyze the differential expression of exosomal microRNAs in apheresis platelet concentrates during storage and predict the potential functions of target genes. Apheresis platelet concentrates were used to isolate exosomes by ultracentrifugation. Exosomes were phenotyped by western blot, transmission electron microscopy, and nano flow cytometry. The differential expression of the exosomal microRNAs was obtained by a microarray test using four bags of apheresis platelets stored for 5 days compared with 1 day. The differentially expressed microRNAs between the two time points were identified, and their target genes were analyzed by miRWalk and miRDB. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed to predict the target genes' functions. Fifteen bags of apheresis platelet concentrates stored for 1 day and 5 days were used to verify the microarray results by quantitative reverse transcription-polymerase chain reactions (qRT-PCR). There were 134 microRNAs in total expressed differently in the two groups (day 1 and day 5), with 57 microRNAs up-regulated and 77 down-regulated (|fold change| > 2.0 and P < .05). Thirteen up-regulated microRNAs (hsa-miR-22-3p, hsa-miR-223-3p, hsa-miR-21-5p, hsa-miR-23a-3p, hsa-miR-320b, hsa-let-7a-5p, hsa-miR-25-3p, hsa-miR-126-3p, hsa-miR-320c, hsa-miR-342-3p, hsa-miR-320d, hsa-miR-328-3p, and hsa-miR-320e) detected in all samples were selected to validate the results. The qRT-PCR results showed that five (hsa-miR-22-3p, hsa-miR-223-3p, hsa-miR-21-5p, hsa-miR-23a-3p, and hsa-miR-320b) of them were increased more than 10-fold (P < .001); four (hsa-let-7a-5p, hsa-miR-25-3p, hsa-miR-126-3p, hsa-miR-320c) more than five-fold (P < .001); two (hsa-miR-342-3p and hsa-miR-320d) more than two-fold (P < .05); and two (hsa-miR-328-3p and hsa-miR-320e) more than two-fold (P > .05). Specifically, hsa-miR-22-3p increased 14.6-fold; hsa-miR-223-3p increased 13.0-fold; and hsa-miR-21-5p increased 12.0-fold. Based on bioinformatics functional analysis, target genes of top nine microRNAs (hsa-miR-22-3p, hsa-miR-223-3p, hsa-miR-21-5p, hsa-miR-23a-3p, hsa-miR-320b, hsa-let-7a-5p, hsa-miR-25-3p, hsa-miR-126-3p, and hsa-miR-320c) were annotated with positive regulation of cell proliferation and nervous system development, and mainly enriched in regulating pluripotency of stem cells signaling pathway, prolactin signaling pathway, and FoxO signaling pathway, etc. The prolactin, FoxO, ErbB, and TNF signaling pathway were relevant to immunomodulation. In particular, hsa-miR-22-3p expression was the most different during storage, with a fold change of 14.6, which might be a key mediator.

The role of extracellular vesicles from stored RBC units in B lymphocyte survival and plasma cell differentiation

Extracellular vesicles (EVs) are small, double-membrane vesicles derived from erythrocytes, leukocytes, platelets, and cells of multiple tissues under physiologic or pathologic conditions. The role of EVs in stored RBC units is of great interest with respect to transfusion-related immunomodulation. The current study focuses on the quantity of EVs isolated from stored RBC units and their action on B cell-mediated immune responses. The in vitro experiment demonstrated that EVs exhibited a negative role in B cell survival, plasmacytic differentiation, and class switch recombination under LPS stimulation. Furthermore, LPS-induced antibody production was significantly decreased after EVs injection in vivo. Biochemical analysis revealed that EVs hampered the expression of Blimp-1 and IRF4 and the activation of NF-κB pathway in LPS-primed B cells. Overall, these data imply a vital role for EVs isolated from RBC units in B cell-mediated immune responses.

Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy With Mitomycin C Used for Colorectal Peritoneal Carcinomatosis

Purpose

This study aimed to assess the evaluation of clinical outcomes and consequences of complications after cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) for the peritoneal carcinomatosis (PC) from colorectal cancer.

Methods

A total 26 patients underwent CRS and HIPEC for PC from colorectal cancer between March 2009 and April 2018. All the patients underwent CRS with the purpose of complete or near-complete cytoreduction. Intraoperative HIPEC was performed simultaneously after the CRS. Mitomycin C was used as chemotherapeutic agent for HIPEC.

Results

Median disease-free survival was 27.8 months (range, 13.4–42.2 months). Median overall survival was 56.0 months (range, 28.6–83.5 months). The mean peritoneal cancer index (PCI) was 8.73 ± 5.54. The distributions thereof were as follows: PCI <10, 69.23%; PCI 10–19, 23.08%; and PCI ≥20, 7.69%. The completeness of cytoreduction was 96.2% of patients showed CC-0, with 3.8% achieved CC-1. The mean operation time was 8.5 hours, and the mean postoperative hospital stay was 21.6 days. The overall rate of early postoperative complications was 88.5%; the rate of late complications was 34.6%. In the early period, most complications were grades I–II complications (65.4%), compared to grades III–V (23.1%). All late complications, occurring in 7.7% of patients, were grades III–V. There was no treatment-related mortality.

Conclusion

Although the complication rate was approximately 88%, but the rate of severe complication rate was low. In selective patients with peritoneal recurrence, more aggressive strategies for management, such as CRS with HIPEC, were able to be considered under the acceptable general condition and life-expectancy.

Peri-operative allogeneic blood transfusion is associated with poor overall survival in advanced epithelial ovarian Cancer; potential impact of patient blood management on Cancer outcomes

BACKGROUND

Transfusion related immune modulation associated with red blood cell (RBC) transfusion is thought to result in decreased cancer survival. Results in epithelial ovarian cancer (EOC) have been mixed however most suggest worse oncologic outcomes in patients who were transfused at the time of debulking surgery. The impact of restrictive transfusion strategies on this patient population is currently not known.

METHODS

We conducted a retrospective study of women with EOC. The study population was divided into two groups based on whether they were transfused RBCs during the peri-operative period or not. Clinical characteristics and prognosticators were compared between groups. Overall survival was compared between groups based on transfusion status and other known prognostic factors. Cox proportional hazard modeling was used to examine the association between the prognostic factors and the study endpoint.

RESULTS

Sixty-six percent of women were transfused. Transfusion was associated with CA125, the use of neoadjuvant chemotherapy (NACT), surgical blood loss, and anemia. The mean pre-transfusion Hgb was 7.8 + 0.6 g/dL and 94% had a hemoglobin level greater than the transfusion threshold of 7 g/dL. RBC transfusion, suboptimal debulking, anemia, and NACT were associated with decreased survival. Only RBC transfusion and suboptimal debulking status remained significant in a multivariate model.

CONCLUSIONS

Peri-operative RBC transfusion compromises survival in ovarian cancer supporting the need to minimize the use of transfusion at the time of debulking surgery. Adherence to evidence-based transfusion guidelines offers an opportunity to reduce transfusion rates in this population with a resulting positive influence on survival.

Allogenic Blood Transfusion Is an Independent Predictor of Poorer Peri-operative Outcomes and Reduced Long-Term Survival after Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy: a Review of 936 Cases

INTRODUCTION

There is a paucity of data on the impact of allogenic blood transfusion (ABT) on morbidity and survival outcomes after cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC).

METHODS

Nine hundred and thirty-five consecutive CRS/HIPEC procedures were performed between 1996 and 2016 at a high-volume institution in Sydney, Australia. Of these, 337(36%) patients required massive ABT (MABT) (≥5 units). Peri-operative complications were graded according to the Clavien-Dindo classification. The association of concomitant MABT with 21 peri-operative outcomes and overall survival (OS) was assessed using univariate and multivariate analyses.

RESULTS

In-hospital mortality was 1.8%. Patients requiring MABT had more extensive disease as reflected by a higher peritoneal cancer index (≥17) (70 vs. 29%, p < 0.001) and longer operative times (≥9 h) (82 vs. 35%, p < 0.001). After accounting for confounding factors, MABT was associated with in-hospital mortality (relative risk (RR), 7.72; 95% confidence interval (CI), 1.35-10.11; p = 0.021) and grade III/IV morbidity (RR, 2.05; 95% CI, 1.42-2.95; p < 0.001). MABT was associated with an increased incidence of prolonged hospital stay (≥28 days) (RR, 1.86; 95% CI, 1.26-2.74; p = 0.002) and intensive care unit stay (≥4 days) (RR, 1.83; 95% CI, 1.24-2.70, p = 0.002). It was also associated with a significant OS in patients with colorectal cancer peritoneal carcinomatosis (RR 4.49; p < 0.001) and pseudomyxoma peritonei (RR, 4.37; p = 0.026), but not appendiceal cancer (p = 0.160).

CONCLUSION

MABT is an independent predictor for poorer peri-operative outcomes including in-hospital mortality and grade III/IV morbidity. It may also compromise long-term survival, particularly in patients with colorectal cancer peritoneal carcinomatosis.

Negative oncologic impact of poor postoperative pain control in left-sided pancreatic cancer

AIM

To investigate the association between postoperative pain control and oncologic outcomes in resected pancreatic ductal adenocarcinoma (PDAC).

METHODS

From January 2009 to December 2014, 221 patients were diagnosed with PDAC and underwent resection with curative intent. Retrospective review of the patients was performed based on electronic medical records system. One patient without records of numerical rating scale (NRS) pain intensity scores was excluded and eight patients who underwent total pancreatectomy were also excluded. NRS scores during 7 postoperative days following resection of PDAC were reviewed along with clinicopathologic characteristics. Patients were stratified into a good pain control group and a poor pain control group according to the difference in average pain intensity between the early (POD 1, 2, 3) and late (POD 5, 7) postoperative periods. Cox-proportional hazards multivariate analysis was performed to determine association between postoperative pain control and oncologic outcomes.

RESULTS

A total of 212 patients were dichotomized into good pain control group (n = 162) and poor pain control group (n = 66). Median follow-up period was 17 mo. A negative impact of poor postoperative pain control on overall survival (OS) was observed in the group of patients receiving distal pancreatectomy (DP group; 42.0 mo vs 5.0 mo, P = 0.001). Poor postoperative pain control was also associated with poor disease-free survival (DFS) in the DP group (18.0 mo vs 8.0 mo, P = 0.001). Patients undergoing pancreaticoduodenectomy or pylorus-preserving pancreaticoduodenectomy (PD group) did not show associations between postoperative pain control and oncologic outcomes. Poor patients’ perceived pain control was revealed as an independent risk factor of both DFS (HR = 4.157; 95%CI: 1.938-8.915; P < 0.001) and OS (HR = 4.741; 95%CI: 2.214-10.153; P < 0.001) in resected left-sided pancreatic cancer.

CONCLUSION

Adequate postoperative pain relief during the early postoperative period has important clinical implications for oncologic outcomes after resection of left-sided pancreatic cancer.

Predictors of mortality within 1 year after primary ovarian cancer surgery: a nationwide cohort study

OBJECTIVES

To identify predictors of mortality within 1 year after primary surgery for ovarian cancer.

DESIGN

Prospective nationwide cohort study from 1 January 2005 to 31 December 2012.

SETTING

Evaluation of data from the Danish Gynaecology Cancer Database and the Danish Civil Registration System.

PARTICIPANTS

2654 women who underwent surgery due to a diagnosis of primary ovarian cancer.

OUTCOME MEASURES

Overall survival and predictors of mortality within 0-180 and 181-360 days after the primary surgery. Examined predictors were age, preoperative American Society of Anesthesiologists (ASA) score, body mass index (BMI), International Federation of Gynaecology and Obstetrics (FIGO) stage, residual tumour tissue after surgery, perioperative blood transfusion and calendar year of surgery.

RESULTS

The overall 1-year survival was 84%. Within 0-180 days after surgery, the 3 most important predictors of mortality from the multivariable model were residual tumour tissue >2 cm versus no residual tumour (HR=4.58 (95% CI 3.20 to 6.59)), residual tumour tissue ≤2 cm versus no residual tumour (HR=2.50 (95% CI 1.63 to 3.82)) and age >64 years versus age ≤64 years (HR=2.33 (95% CI 1.69 to 3.21)). Within 181-360 days after surgery, FIGO stages III-IV versus I-II (HR=2.81 (95% CI 1.75 to 4.50)), BMI<18.5 vs 18.5-25 kg/m(2) (HR=2.08 (95% CI 1.18 to 3.66)) and residual tumour tissue >2 cm versus no residual tumour (HR=1.84 (95% CI 1.25 to 2.70)) were the 3 most important predictors.

CONCLUSIONS

The most important predictors of mortality within 1 year after surgery were residual tumour tissue (0-180 days after surgery) and advanced FIGO stage (181-360 days after surgery). However, our results suggest that the surgeon should not just aim at radical surgery, but also pay special attention to comorbidity, nutritional state, age >64 years and the need for perioperative blood transfusion.

Risk factors and outcomes of blood transfusions in adrenalectomy

BACKGROUND

Blood transfusion has been shown to be associated with adverse long-term and short-term outcomes. We sought to evaluate the preoperative risk factors associated with blood transfusion and its effects on postoperative outcomes after adrenalectomy.

METHODS

We performed a retrospective analysis of 4735 adrenalectomies (3664 laparoscopic and 1071 open) from 2005-2012 using the National Surgical Quality Improvement Program database. Data on preoperative risk factors and postoperative morbidity and mortality were evaluated.

RESULTS

Median age and body mass index were 54 y and 29.3 kg/m(2), respectively. Most patients were female (60.0%). Of the total, 60.6% patients had American Society of Anesthesiologists score ≥3. On multivariate analysis, increasing age (odds ratio [OR] = 1.02, P < 0.001), open adrenalectomy (OR = 14.0, P < 0.001), preoperative hematocrit <38% (OR = 2.96, P < 0.001), and operative time >150 min (OR: 3.69, P < 0.001) were associated with an increased need for intraoperative blood transfusions. The need for intraoperative blood transfusions was an independent predictor of postoperative complications including mortality (OR = 12.7, P < 0.001), overall morbidity (OR = 3.2, P < 0.001), serious morbidity (OR = 3.8, P < 0.001), wound complication (OR = 2.1, P = 0.006), cardiopulmonary complication (OR = 3.6, P < 0.001), septic complication (OR = 2.5, P = 0.007), reoperation (OR = 3.6, P < 0.001), and prolonged length of stay (OR = 4.3, P < 0.001). There was an independent and incremental increase (10%-20%) in the risk of morbidity and mortality with each unit of blood transfused (P < 0.01).

CONCLUSIONS

Age, open surgery, preoperative anemia, American Society of Anesthesiologists score, and prolonged operative time are associated with an increased need for blood transfusions in laparoscopic and open adrenalectomy. Intraoperative transfusion was independently and incrementally associated with significant morbidity and mortality after laparoscopic and open adrenalectomy.

Exploiting the critical perioperative period to improve long-term cancer outcomes

Evidence suggests that the perioperative period and the excision of the primary tumour can promote the development of metastases—the main cause of cancer-related mortality. This Review first presents the assertion that the perioperative timeframe is pivotal in determining long-term cancer outcomes, disproportionally to its short duration (days to weeks). We then analyse the various aspects of surgery, and their consequent paracrine and neuroendocrine responses, which could facilitate the metastatic process by directly affecting malignant tissues, and/or through indirect pathways, such as immunological perturbations. We address the influences of surgery-related anxiety and stress, nutritional status, anaesthetics and analgesics, hypothermia, blood transfusion, tissue damage, and levels of sex hormones, and point at some as probable deleterious factors. Through understanding these processes and reviewing empirical evidence, we provide suggestions for potential new perioperative approaches and interventions aimed at attenuating deleterious processes and ultimately improving treatment outcomes. Specifically, we highlight excess perioperative release of catecholamines and prostaglandins as key deleterious mediators of surgery, and we recommend blockade of these responses during the perioperative period, as well as other low-risk, low-cost interventions. The measures described in this Review could transform the perioperative timeframe from a prominent facilitator of metastatic progression, to a window of opportunity for arresting and/or eliminating residual disease, potentially improving long-term survival rates in patients with cancer.

Perioperative blood transfusion in gynecologic oncology surgery: analysis of the National Surgical Quality Improvement Program Database

OBJECTIVE

To use a large-scale multi-institutional dataset to quantify the prevalence of packed red blood cell transfusions and examine the associations between transfusion and perioperative outcomes in gynecologic cancer surgery.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program (NSQIP) participant use file was queried for all gynecologic cancer cases between 2010 and 2012. Demographic, preoperative and intraoperative variables were compared between transfusion and non-transfusion groups using chi-squared, Fisher's exact and Wilcoxon rank-sum tests. The primary endpoint was 30-day composite morbidity. Secondary endpoints included composite surgical site infections, mortality and length of stay.

RESULTS

A total of 8519 patients were analyzed, and 13.8% received a packed red blood cell transfusion. In the multivariate analysis, after adjusting for key clinical and perioperative factors, including preoperative anemia and case magnitude, transfusion was associated with higher composite morbidity (OR = 1.85, 95% CI 1.5-2.24), surgical site infections (OR 1.80, 95% CI 1.39-2.35), mortality (OR 3.38, 95% CI 1.80-6.36) and length of hospital stay (3.02 days v. 7.17 days, P < 0.001).

CONCLUSIONS

Blood transfusions are associated with increased surgical wound infections, composite morbidity and mortality. Based on our analysis of the NSQIP database, transfusion practices in gynecologic cancer should be scrutinized. Examination of institutional practices and creation of transfusion guidelines for gynecologic malignancies could potentially result in better utilization of blood bank resources and clinical outcomes among patients.

Plasma cytokines and markers of endothelial activation increase after packed red blood cell transfusion in the preterm infant

BACKGROUND

Transfusion of packed red blood cells (PRBCs) saves lives in the neonatal critical care setting and is one of the most common interventions in the preterm infant. The number and volume of PRBC transfusions are associated with several major neonatal morbidities, although a direct causal link between transfusion and major neonatal morbidity is still to be proven. Transfusion-related immunomodulation (TRIM) may underlie these adverse outcomes, yet it has received little attention in the high-risk preterm infant.

METHODS

One transfusion event was studied in infants ≤28 wk gestation between 2 and 6 wk postnatal age (n = 28). Plasma inflammatory cytokines and markers of endothelial activation were measured in the infants before and 2-4 h after transfusion, as well as in the donor pack.

RESULTS

Median (range) age at transfusion was 18 (14-39) days with the pretransfusion hemoglobin level at 9.8 (7.4-10.2) g/dl. Interleukin (IL)-1β (P = 0.01), IL-8 (P = <0.001), tumor necrosis factor-α (P = 0.008), and monocyte chemoattractant protein (P = 0.01) were increased after transfusion. A similar elevation in markers of endothelial activation was seen after transfusion with increased plasma macrophage inhibitory factor (P = 0.005) and soluble intracellular adhesion molecule-1 (P = <0.001).

CONCLUSION

Production of inflammatory cytokines and immunoactivation of the endothelium observed after the transfusion of PRBCs in the preterm infant may be a manifestation of TRIM. The implications of this emerging phenomenon within the preterm neonatal population warrant further investigation.

Washing red blood cells and platelets transfused in cardiac surgery reduces postoperative inflammation and number of transfusions: results of a prospective, randomized, controlled clinical trial

OBJECTIVES

Children undergoing cardiac surgery with cardiopulmonary bypass are susceptible to additional inflammatory and immunogenic insults from blood transfusions. We hypothesize that washing red blood cells and platelets transfused to these patients will reduce postoperative transfusion-related immune modulation and inflammation.

DESIGN

Prospective, randomized, controlled clinical trial.

SETTING

University hospital pediatric cardiac intensive care unit.

PATIENTS

Children from birth to 17 yrs undergoing cardiac surgery with cardiopulmonary bypass.

INTERVENTIONS

Children were randomized to an unwashed or washed red blood cells and platelet transfusion protocol for their surgery and postoperative care. All blood was leuko-reduced, irradiated, and ABO identical. Plasma was obtained for laboratory analysis preoperatively, immediately, and 6 and 12 hrs after cardiopulmonary bypass. Primary outcome was the 12-hr postcardiopulmonary bypass interleukin-6-to-interleukin-10 ratio. Secondary measures were interleukin levels, C-reactive protein, and clinical outcomes.

MEASUREMENTS AND MAIN RESULTS

One hundred sixty-two subjects were studied, 81 per group. Thirty-four subjects (17 per group) did not receive any blood transfusions. Storage duration of blood products was similar between groups. Among transfused subjects, the 12-hr interleukin ratio was significantly lower in the washed group (3.8 vs. 4.8; p = .04) secondary to lower interleukin-6 levels (after cardiopulmonary bypass: 65 vs.100 pg/mL, p = .06; 6 hrs: 89 vs.152 pg/mL, p = .02; 12 hrs: 84 vs.122 pg/mL, p = .09). Postoperative C-reactive protein was lower in subjects receiving washed blood (38 vs. 43 mg/L; p = .03). There was a numerical, but not statistically significant, decrease in total blood product transfusions (203 vs. 260) and mortality (2 vs. 6 deaths) in the washed group compared to the unwashed group.

CONCLUSIONS

Washed blood transfusions in cardiac surgery reduced inflammatory biomarkers, number of transfusions, donor exposures, and were associated with a nonsignificant trend toward reduced mortality. A larger study powered to test for clinical outcomes is needed to determine whether these laboratory findings are clinically significant.

Intravenous delivery of the plasma fraction of stored packed erythrocytes promotes pancreatic cancer growth in immunocompetent mice

BACKGROUND

Perioperative blood transfusion in pancreatic cancer patients has been linked to decreased survival; however, a causal mechanism has not been determined. During the processing and storage of packed erythrocytes, biologically active molecules accumulated in the acellular plasma fraction; therefore, the authors hypothesized that the plasma fraction of stored packed erythrocytes promoted tumor progression.

METHODS

Proliferation and migration of murine pancreatic cancer and control cells were determined in vitro in response to the plasma fraction from leukocyte and nonleukocyte-reduced fresh versus stored packed erythrocytes. Last, an immunocompetent murine model was used to assess the effect of the plasma fraction of stored and processed packed erythrocytes on pancreatic cancer progression.

RESULTS

Incubation of pancreatic cancer cells with the plasma fraction of packed erythrocytes increased proliferation and migration. Intravenous delivery of the acellular plasma fraction to mice with pancreatic cancer significantly increased the tumor weight in both leukocyte-reduced and nonleukocyte-reduced packed-erythrocyte groups (P<.01), although tumor growth and morbidity were greatest in the nonleukocyte-reduced group.

CONCLUSIONS

The plasma fraction of stored packed erythrocytes promoted murine pancreatic cancer proliferation and migration in vitro and when administered intravenously, significantly augmented pancreatic cancer growth in immunocompetent mice.

Proteomic analysis of supernatants of stored red blood cell products

BACKGROUND

The development of the red blood cell (RBC) storage lesion remains incompletely understood. To gain a greater insight into the mechanisms involved, a proteomics analysis was used to identify proteins that accumulate in supernatants of standard nonleukoreduced RBC products (S-RBCs) and prestorage leukofiltered RBC products (LF-RBCs) during storage.

STUDY DESIGN AND METHODS

S-RBCs and LF-RBCs were collected and stored in accordance with standard blood bank procedures. Supernatant samples were collected at fortnightly intervals until product expiry (at Day 42). Maps of supernatant proteins were generated by two-dimensional (2D)-gel electrophoresis and selected proteins were identified by mass spectrometry.

RESULTS

2D-gel mapping revealed that greater numbers of proteins accumulated in supernatants of S-RBCs compared to LF-RBCs. Abundant plasma proteins were strongly represented in both products. Several potentially bioactive proteins were found to predominantly accumulate in supernatant of S-RBCs. Among these, a promoter of neutrophil adhesion and an acute-phase scavenger protein were identified. In contrast, proteins found to accumulate predominantly in supernatant of LF-RBCs were RBC-regulatory proteins.

CONCLUSION

Proteomics provides a valuable approach to examine storage-related effects on RBCs. Such analytical approaches may help to elucidate the mechanisms involved in the RBC storage lesion and provide insights into the biologic consequences of transfusion of stored RBC products.

Induction of immune tolerance across major histocompatibility complex barrier by transfusion of ultraviolet B-irradiated immature dendritic cells

BACKGROUND

Transfusion of ultraviolet B (UVB)-irradiated peripheral blood mononuclear cells (PBMNCs) induces immunologic tolerance across the major histocompatibility complex (MHC) barrier in a murine model. It is necessary, however, to reduce contaminating platelets (PLTs) to a minimum. Ex vivo preparation of dendritic cells (DCs) offers an opportunity to rid the contaminating PLTs. The use of immature and mature DCs (iDCs and mDCs) with and without UVB irradiation for tolerance induction was therefore investigated.

STUDY DESIGN AND METHODS

iDCs and mDCs were prepared by culture of Balb/c (H-2d) mouse marrow cells in the presence of granulocyte-macrophage-colony-stimulating factor and interleukin-4. Different dose schedules of iDCs were tested for tolerance induction in CBA (H-2k) mice. Tolerance induction by UVB-irradiated iDCs and mDCs was compared. Tolerance induction in two additional strains of mice (C3H and C57BL/6) was also studied. The induction of tolerance was tested by challenging transfusions of treated mice with PBMNCs from the donor strain. The induction of negative regulatory CD4+ T cells in tolerized mice was examined.

RESULTS

Four weekly transfusions of 5 x 10(4) UVB-irradiated iDCs from Balb/c mice efficiently induced immune tolerance in CBA and C3H mice. iDCs and mDCs without UVB irradiation could not induce immune tolerance. Tolerance induced by transfusions of UVB-irradiated iDCs was associated with the development of CD4+-regulatory T cells as demonstrated by an adoptive transfer study.

CONCLUSION

Transfusion of UVB-iDCs induces immune tolerance across the MHC barrier in certain combinations of mouse strains. The results support the idea that iDCs irradiated with UVB may be applied to induce immune tolerance across the MHC barrier.

The next generation in shock resuscitation

Resuscitation of the severely injured patient who presents in shock has improved greatly, following focused wartime experience and insight from laboratory and clinical studies. Further benefit is probable from technologies that are being brought into clinical use, especially hypertonic saline dextran, haemoglobin-based oxygen carriers, less invasive early monitors, and medical informatics. These technologies could improve the potential of prehospital and early hospital care to pre-empt or more rapidly reverse hypoxaemia, hypovolaemia, and onset of shock. Damage control surgery and definitive interventional radiology will probably combine with more real-time detection and intervention for hypothermia, coagulopathy, and acidosis, to avoid extreme pathophysiology and the "bloody vicious cycle". Although now widely practised as standard of care in the USA and Europe, shock resuscitation strategies involving haemoglobin replacement and fluid volume loading to regain tissue perfusion and oxygenation vary between trauma centres. One of the difficulties is the scarcity of published evidence for or against seemingly basic intervention strategies, such as early or large-volume fluid loading. Standardised protocols for resuscitation, representing the best and most current knowledge of the clinical process, could be devised and widely implemented as interactive computerised applications among trauma centres in the USA and Europe. Prevention of injury is preferable and feasible, but early care of the severely injured patient and modulation of exaggerated systemic inflammatory response due to transfusion and other complications of traditional strategies will probably provide the next generation of improvements in shock resuscitation.

Supernatant from stored red blood cell primes inflammatory cells: influence of prestorage white cell reduction

BACKGROUND

The contribution of RBC transfusion to adverse patient outcomes is controversial. There is conflicting clinical data and limited biologic data that provide an underpinning biologic rationale for any adverse impacts from RBC transfusion. This study used in-vitro measures of PMN stimulation to determine the ability of supernatant from RBCs to stimulate allogeneic WBCs and to determine the influence of residual donor WBCs and storage time on the proinflammatory potential of RBCs.

STUDY DESIGN AND METHODS

Three types of RBCs were assessed: standard non-WBC-reduced RBCs (S-RBCs), buffy coat-poor RBCs (BCP-RBCs), and prestorage WBC-filtered RBC (LF-RBCs). Supernatant was collected weekly up to Day 42 of storage. PMN priming by supernatant from RBCs was determined by three methods: induction of CD11b expression on PMNs, induction of IL-8 release from PMNs, and the chemotactic effect of supernatant on PMNs.

RESULTS

Supernatant from S-RBCs induced the expression of CD11b on PMNs, primed PMNs to release IL-8, and was chemotactic for PMNs. The magnitude of this PMN-priming progressively amplified with storage time. In contrast, supernatant from BCP-RBCs or LF-RBCs did not significantly prime PMNs. The PMN-priming effect of supernatant from RBCs correlated more closely with the level of MNCs in the RBCs than PMN content.

CONCLUSION

Supernatant from stored S-RBCs prime unstimulated allogeneic PMNs in vitro. Prestorage buffy-coat WBC reduction was as effective as WBC depletion in abrogating this proinflammatory response elicited by supernatants from RBCs. The clinical consequences, if any, of these findings for transfusion recipients are unknown.

Expression of Fas and Fas ligand on spleen T cells of experimental animals after unmodified or leukoreduced allogeneic blood transfusions

BACKGROUND

The clonal deletion seen in recipients of allogeneic blood transfusion (ABT) refers to the removal of lymphocytes that promote the clearance of transfused alloantigens. Interactions between Fas (CD95) and FasL (CD95L) are involved in the clonal deletion of T cells and in the down regulation of the cytotoxic T-cell activity.

STUDY DESIGN AND METHODS

The expression of CD95/95 L on spleen T cells of C57Bl/6 mice infused with unmodified ABT, prestorage leukoreduced ABT (LR-ABT), or saline was investigated by flow cytometry. The numbers of apoptotic spleen cells were evaluated after transfusion using the acridine orange and ethidium bromide uptake technique.

RESULTS

Compared with untransfused animals, mice transfused with ABT showed higher expression of CD95 (MFI = 94.4 +/- 8.6 vs. 73.1 +/- 7.9, p = 0.02) and CD95L (23.5 +/- 6.9 vs. 8.1 +/- 2.0, p = 0.008) on CD4+ spleen cells. Expression of CD95 (92.2 +/- 7.5 vs. 64.9 +/- 7.5, p = 0.007) and CD95L (17.7 +/- 3.6 vs. 8.2 +/- 2.2, p = 0.02) was also increased on CD8+ cells of these animals. CD8+ spleen cells from mice transfused with ABT showed higher expression of CD95 (92.2 +/- 7.5 vs. 76.9 +/- 4.0, p = 0.03) and CD95L (17.7 +/- 3.6 vs. 8.3 +/- 1.5, p = 0.03) than cells from mice transfused with LR-ABT. The number of apoptotic spleen cells from mice transfused with ABT was greater than that from mice infused with LR-ABT (10.9 +/- 1.3 vs. 6.6 +/- 1.8, p = 0.01) or saline (10.9 +/- 1.3 vs. 6.5 +/- 0.7, p = 0.001).

CONCLUSIONS

The data suggest that ABT up-regulates the expression of Fas/FasL on spleen T cells of mice and may promote their apoptosis. These ABT-associated immunologic alterations can be partially prevented by the leukoreduction of the transfused blood.

Red cell transfusion "trigger": a review

Despite the publication of several consensus guidelines that set forth recommendations for the transfusion of red cells, actual clinical practice continues to vary widely. Animal data and studies in human volunteers and patients support a red cell transfusion threshold of 7 to 8 g/dl in most patients. However, conflicting data, particularly in cardiac patients and in the elderly, suggest that it may be impossible to define a single red cell "trigger" for all patients. A well-designed, randomized, controlled trial is still needed to establish a safe threshold for red cell transfusion in adults with coronary artery disease.

The effect of exposing murine splenocytes to UVB light, psoralen plus UVA light, or gamma-irradiation on in vitro and in vivo immune responses

BACKGROUND

WBCs in blood components are a major factor contributing to immune responses such as GVHD and alloimmunization that follow transfusion. Irradiation of blood components has been used to regulate the contribution of donor WBCs to these immune responses. A systematic comparison of how the exposure of lymphoid cells to gamma-irradiation, UVB light, or psoralen + UVA light (PUVA) effects immune response was conducted to better define the best type of irradiation to be used in different clinical settings.

STUDY DESIGN AND METHODS

Murine spleen cells were irradiated with varying doses and tested for their in vitro ability to be activated, to proliferate in response to mitogen or allogeneic stimulator cells, or to serve as stimulator cells. Irradiated donor cells were also tested for in vivo generation of GVHD, induction of alloantibody production, induction of restricted cytolytic T lymphocytes, and persistence of irradiated cells.

RESULTS

In general, increasing amounts of irradiation resulted in increased inhibition of in vitro and in vivo responses, although the doses required for inhibition differed from assay to assay. In contrast, irradiation of donor cells did not always result in inhibition of recipient alloantibody responses but was dependent on the donor-recipient combination that was studied.

CONCLUSION

Control of the in vivo outcomes of transfusing allogeneic cells is regulated by the type and dose of irradiation used and by the genotype of the donor and/or recipient.

Inhibition of murine GVHD by PEN110 treatment

BACKGROUND

The presence of WBCs in blood components is the primary factor influencing the immunologic consequences of transfusion, such as GVHD and alloimmunization. Depletion or inactivation of WBCs can reduce the deleterious responses. Because treatment with PEN110 (Inactine, V. I. Technologies), an ethyleneimine derivative that disrupts nucleic acid replication, was shown to inactivate in vitro human PBMNC function, the ability of PEN110-treated cells to trigger GVHD or alloantibodies was studied with in vivo murine models.

STUDY DESIGN AND METHODS

In vitro assays were employed to confirm that PEN110 treatment inactivated murine splenocyte function as effectively as for human PBMNCs. In vivo experiments in mice examined the ability of PEN110-treated cells to induce GVHD responses in a parent into F1 hybrid GVHD model, to induce alloantibodies, to stimulate MHC-restricted cytolytic T lymphocyte responses, and to persist after injection.

RESULTS

PEN110-treated murine splenocytes did not respond or induce responses in any in vitro or in vivo assay. The PEN110-treated cells were eliminated from blood and secondary lymphoid organs much more rapidly than were untreated cells.

CONCLUSION

PEN110 treatment prevents the development of GVHD and alloantibody production following WBC transfusion in a murine model system, supporting the continued development of PEN110 treatment of cellular blood components as an alternative to gamma irradiation for the prevention of GVHD.

PEN110 treatment functionally inactivates the PBMNCs present in RBC units: comparison to the effects of exposure to gamma irradiation

BACKGROUND

The presence of WBCs in blood components is the major factor influencing the immunologic consequences of transfusion. Attempts to ameliorate these responses have used WBC reduction or inactivation by ionizing radiation. PEN110 (Inactine, V. I. Technologies) is a chemical that inhibits the replication of infectious pathogens by modifying their nucleic acids. These experiments compared effects of PEN110 treatment or gamma irradiation on WBC function.

STUDY DESIGN AND METHODS

Aliquots of non-WBC-reduced RBC units were treated with PEN110 or gamma irradiation with appropriate controls, and PBMNCs from these units were tested with in vitro assays. The assays included immunophenotyping, activating T cells with phorbol ester, proliferation of cells in response to mitogens or allogeneic cells, and determining the ability of cells to stimulate proliferative responses and to produce IL-8. DNA fragmentation following PEN110 treatment was examined by PCR and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling assays.

RESULTS

Treatment of non-WBC-reduced RBC units with PEN110 functionally inactivated WBC in all in vitro assays used. In contrast, while gamma irradiation inhibited proliferation of the WBCs, it did not or only partially inhibited the ability of WBC to function in the other assays. PEN110, but not gamma irradiation, rapidly induced fragmentation of cellular DNA.

CONCLUSION

Because PEN110 was as effective as gamma irradiation at inhibiting WBC proliferation, PEN110 treatment could potentially be used to prevent the development of GVHD following transfusion.

Plasma from aged stored red blood cells delays neutrophil apoptosis and primes for cytotoxicity: abrogation by poststorage washing but not prestorage leukoreduction

BACKGROUND

Blood transfusion-particularly that of older stored red blood cells (RBCs)--is an independent risk factor for postinjury multiple organ failure. Immunomodulatory effects of RBC transfusion include neutrophil (PMN) priming for cytotoxicity, an effect exacerbated by longer RBC storage times. We have found that delayed PMN apoptosis in trauma patients is provoked by transfusion, independent of injury severity. We hypothesized that aged stored RBCs delay PMN apoptosis, but that prestorage leukodepletion or poststorage washing could abrogate the effect.

METHODS

Healthy volunteers each donated 1 unit of blood. One half was leukodepleted, and RBC units were processed in the usual fashion and stored at 4 degrees C. Aliquots were removed on days 1, 14, 21, and 42 and the plasma fraction isolated. Selected aliquots were washed with normal saline before plasma isolation. PMNs harvested from healthy controls were incubated (5% CO2, 37 degrees C) with unmodified, leukoreduced, or washed RBC plasma (20% plasma/80% RPMI 1640), and apoptosis assessed by morphology after 24 hours. Apoptotic index (apoptotic PMNs/total PMNs) was compared. PMN priming for superoxide release was also assessed after plasma exposure.

RESULTS

PMN apoptosis was delayed by RBCs stored for 21 or 42 days. Prestorage leukodepletion did not alter the effect. However, washing 42-day-old RBCs abrogated the effect. PMN priming for superoxide was provoked by stored packed RBCs in an identical pattern to delayed apoptosis.

CONCLUSION

Plasma from stored RBCs-even if leukoreduced-delays apoptosis and primes PMNs. The effect becomes evident at 21 days and worsens through product outdate (42 days), but may be prevented by poststorage washing. Inflammatory agents contaminating stored blood likely mediate the effect. Modification of transfusion practices (e.g., giving fresher or washed RBCs or blood substitutes) may attenuate adverse immunomodulatory effects of transfusion in trauma patients.