Red Cell Recovery Research Articles

Iron-deficient erythropoiesis in blood donors and red blood cell recovery after transfusion: initial studies with a mouse model.

Most frequent red cell (RBC) donors and many first-time donors are iron deficient, but meet haemoglobin standards. However, the effects of donation-induced iron deficiency on RBC storage quality are unknown. Thus, we used a mouse model to determine if donor iron deficiency reduced post-transfusion RBC recovery. Weanling mice received a control diet or an iron-deficient diet. A third group receiving the iron-deficient diet was also phlebotomised weekly. This provided 3 groups of mice with different iron status: (1) iron replete, (2) mild iron deficiency with iron-deficient erythropoiesis, and (3) iron-deficiency anaemia. At ten weeks of age, blood was collected, leucoreduced, and stored at 4 ºC. After 12 days of storage, 24-hour (h) post-transfusion RBC recovery was quantified in recipients by flow cytometry. Before blood collection, mean haemoglobin concentrations in the iron-replete, iron-deficient, and iron-deficiency anaemia donor mice were 16.5±0.4, 11.5±0.4, and 7.0±1.4 [g/dL± 1 standard deviation (SD)], respectively (p<0.01 for all comparisons between groups). The 24-h post-transfusion RBC recoveries in recipients receiving transfusions from these three cohorts were 77.1±13.2, 66.5±10.9, and 46.7±15.9 (% ±1 SD), respectively (p<0.05 for all comparisons between groups). In summary, donor iron deficiency significantly reduced 24-h post-transfusion RBC recovery in recipient mice. RBCs from mice with mild iron deficiency and iron-deficient erythropoiesis, with haemoglobin levels similar to those used for human autologous blood donation, had intermediate post-transfusion RBC recovery, as compared to iron-replete donors and those with iron-deficiency anaemia. This suggests that, in addition to the effects of iron deficiency on donor health, frequent blood donation, leading to iron-deficient erythropoiesis, may also have adverse effects for transfusion recipients.

The FLT3 Inhibitor Quizartinib Provides a Novel Strategy to Inhibit Chemotherapy-Induced Myelosuppression

IntroductionChemotherapy-inducedmyelosuppressionis a major complication for cancer patients causing high rates of morbidity and mortality. Furthermore,myelosuppressionis frequently managed by delaying and/or reducing the scheduled dose, and as a consequence the efficacy of the treatment can be compromised.Since chemotherapy remains the cornerstone for treating many cancers, the development of compounds that inhibitmyelosuppressionwould provide considerable health benefits. By repurposing quizartinib we have identified a novel approach to managemyelosuppression, which led to the development of an effective treatment for a mouse model of acute myeloidleukemia(AML).MethodsQuizartinib was administered to C57BL/6 mice by oral gavage with a single priming dose of 10 or 30 mg/kg. Fluorouracil (5-FU) was administered byintraperitonealinjection at 150 mg/kg 6-12 hours later. This schedule was repeated every 10 days to examine the protective effects of quizartinib from multiple cycles of 5-FU. The approach of quizartinib priming plus 5-FU every 10 days was examined as a treatment for a mouse model of AML.ResultsThis work is based on studies from mice showing that a single dose of the FLT3 inhibitor quizartinib induces a rapid but transient quiescence of multipotentprogenitors (MPPs). MPPs are highly proliferative FLT3-expressing cells that are responsible for maintaining life-long blood production. They are markedly depleted by chemotherapy so their loss is a significant component of myelosuppression. We found that a single dose of quizartinib 6-12 hours before 5-FU resulted in a 10-fold increase in the survival of MPPs two days after administration. Quizartinib priming also provided significant protection to hematopoietic stem cells and committed progenitors within the lin-, Sca-1-, c-Kit+ population.Analysis of bone marrow at 2-10 days after a single 5-FU injection revealed the rapid recovery conferred to quizartinib-primed mice compared to mice primed with vehicle (Fig. 1).To test whether quizartinib provided protection from multiple cycles of 5-FU we injected mice once every 10 days with 5-FU following a priming dose of quizartinib or vehicle 12 hrsearlier. This 10-day cycle of 5-FU is a potent regimen that causes bone marrow failure and lethality. We found that quizartinib priming promoted a marked level of protection, with only 1 of 5 mice dying over a period of 15 cycles, whereas all vehicle-primed mice succumbed between the 4th and 6th cycles. In addition, we found that quizartinib-primed mice did not lose weight and showed a rapid recovery of white and red blood cells and platelets.From these findings we hypothesized that quizartinib priming before chemotherapy may provide a safe and effective approach for treating cancers that are independent of FLT3signaling. We tested this with an AML model developed from Npm1c x FLT3-ITD(F692L) mutant mice. The F692L mutation confers resistance to quizartinib. The suitability of this model was confirmed from experiments showing that quizartinib dosing did not induce quiescence of Npm1c x FLT3-ITD(F692L) AML cells, nor did it protect them from 5-FU. A cohort of non-irradiated B6.CD45.1 mice transplanted with Npm1c x FLT3-ITD(F692L) AML cells was therefore established. At 16 days after transplantation, when AML cells were evident in the peripheral blood, the mice were divided into three groups: (i) untreated, (ii) induction therapy treated, and (iii) quizartinib primed + 5-FU treated.The induction therapy involved two rounds ofcytarabineat 50 mg/kg for 5 days and doxorubicin at 1.5 mg/kg for 3 days (i.e. 5+3 therapy). All mice in the untreated and induction chemotherapy-treated groups succumbed within 30 and 56 days respectively (Fig. 2). In contrast, only 1 of 5 mice treated by 9 cycles of quizartinib priming + 5-FU succumbed (at day 121). The remaining 4 mice were healthy at 176 days after transplantation, and no AML cells were detectable in their blood or BM. Furthermore, surviving mice had WBC counts within the normal range.ConclusionsThis work has shownthat priming mice with quizartinib provides significant protection to the hematopoietic system from 5-FU cytotoxicity. This has resulted in the development of a novel quizartinib + 5-FU treatment protocol for a preclinical model of AML whereby it markedly enhanced the survival of mice compared to mice receiving conventional therapy. [Display omitted] [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Hematopoietic Recovery after in-Vivo T-Cell Depleted Allogeneic Stem Cell Transplant- Effects of ABO Incompatibility, Rhesus Incompatibility and Acute Gvhd

Background:Transfusion needs after allogeneic transplantation are closely associated with morbidity, cost of transplantation and may also be associated with long-term outcome. In an effort to better predict determinants of recovery after reduced intensity conditioning, we analyzed 214 consecutive patients who received allogeneic hematopoietic stem cell transplantation (HSCT) at our institution from January 2012 to December 2013.Patients and Methods:We excluded patients who experienced early (in the first 4 months) relapse (n=28), non-relapse mortality (n=28) or who experienced prolonged hospital stay before day 100 for transplant related complications (n=51). One hundred and seven patients had uneventful recovery until day 100 and met the inclusion criteria. The majority of patients received Fludarabine and melphalan conditioning (87%). Approximately one third each of the patients had HLA-identical related, HLA-matched unrelated donors or underwent haplo-cord transplantation. Recipients of HLA-identical related or unrelated donor transplant received alemtuzumab and post-transplant tacrolimus. Haplo-cord recipients received thymoglobulin and post-transplant tacrolimus and mycophenolate. Patients and transplant characteristics are summarized in table 1. T-tests were used for comparison between groups.Results: In our analysis of 107 patients who underwent T cell depleted allogeneic transplantation and fared well at day 100, the determinants of prolonged anemia were ABO incompatibility (p=0.006), rhesus incompatibility (p=0.01) and acute graft versus host disease (aGVHD) (p=0.02). Whereas prolonged thrombocytopenia was only associated with the development of any grade aGVHD (p=0.04). At day 100, the hematopoietic recovery of haplo-cord grafts is similar to matched related and unrelated grafts.Conclusion:ABO incompatibility, rhesus incompatibility and occurrence of acute graft vs host disease are the major determinants of red blood cell recovery. Occurrence of acute graft vs host disease is a major determinant of platelet recovery. Of interest, the use of umbilical cord blood grafts combined with haplo-identical grafts is associated with recovery of red blood cells and platelets that is similar to that of adult donor grafts. DisclosuresNo relevant conflicts of interest to declare.

Bone marrow granulocytes drive hematopoietic and vascular regeneration

Bone marrow (BM) vascular regeneration is absolutely necessary for hematopoietic recovery after myeloablation, yet the mechanisms of vascular regeneration are poorly understood. We found that, two weeks after lethal irradiation and BM transplantation, mice transplanted with 20x106 bone marrow nucleated cells (BMNC) had ∼6-fold more CD45-Ter119-CD31+CD105+ endothelial cells (6.9x103 vs 0.96x103 p < 0.001), increased blood vessels (195 vs 97 vessels per segment, p < 0.05), and reduced BM vascular leakage (4.8 vs 9.3 ng/mL of extravasated Evans Blue dye p < 0.001) than mice transplanted with 105 BMNC. These indicated that hematopoietic cells crosstalk with the vasculature to promote vascular regeneration. Adoptive transfer of the major BM hematopoietic populations into lethally irradiated mice demonstrated that only Gr1+CD115- granulocytes are capable of promoting vascular regeneration (2.52x103 for granulocyte treated mice vs 0.9x103 for PBS p < 0.01, 0.3x103 for B- and T-cells, 0.7x103 for monocyte/macrophages, and 0.3x103 for erythroid lineage treated mice). Granulocyte transfer also promoted survival (granulocytes=100%, PBS=50% p < 0.05), probably due to faster recovery of blood platelets and red blood cells in peripheral blood (granulocytes= 4.5x107 PLT/ml and 6.2x109 RBC/ml; PBS= 2.1x107 PLT/ml and 4x109 RBC/ml, p < 0.01). To investigate the mechanisms of granulocyte-mediated vascular recovery, we profiled expression of angiogenic factors. We found that granulocytes were the main source of TNFα in the BM and Tnfrsf1a (the TNFα receptor) was specifically upregulated in BM endothelial cells. To test whether TNFα is necessary for vascular regeneration, we myeloablated WT or Tnfα-/- mice with 5-fluorouracil. Tnfα-/- mice showed dramatically reduced survival (13% vs 93% p < 0.001) and reduced numbers of BM endothelial cells (4.2x103 vs 9x103 p < 0.05) when compared with WT mice. Taken together these results indicate that TNFα is necessary for survival and vascular regeneration after myeloablation. In adoptive transfer experiments only WT, but not Tnfα-/- granulocytes promoted vascular regeneration (PBS= 0.9x103, WT= 5.24x103, and Tnfα-/- = 3.0x103endothelial cells/femur, p < 0.05). These results demonstrate that BM granulocytes crosstalk with the endothelial cells via TNFα to promote vascular and hematopoietic regeneration.

ABO-Mismatched Allogeneic Hematopoietic Stem Cell Transplantation

Allogeneic hematopoietic stem cell transplantation (HSCT) is a curative option for a variety of malignant and non-malignant hematological and congenital diseases. Due to the fact that the human leukocyte antigen system is inherited independently of the blood group system, approximately 40-50% of all HSCTs are performed across the ABO blood group barrier. The expected immune-hematological consequences after transplantation of an ABO-mismatched stem cell graft are immediate and delayed hemolytic complications due to presence of isohemagglutinins or passenger lymphocyte syndrome. The risks of these complications can partially be prevented by graft manipulation and appropriate transfusion support. Dependent on the kind of ABO mismatch, different effects on engraftment have been observed, e.g. delayed red blood cell recovery and pure red cell aplasia. Data on incidence of acute graft-versus-host disease (GVHD), non-relapse mortality, relapse, and overall survival are inconsistent as most studies include limited patient numbers, various graft sources, and different conditioning and GVHD prophylaxis regimens. This makes it difficult to detect a consistent effect of ABO-mismatched transplantation in the literature. However, knowledge of expectable complications and close monitoring of patients helps to detect problems early and to treat patients efficiently, thus reducing the number of fatal or life-threatening events caused by ABO-mismatched HSCT.

Novel method to leukoreduce murine blood for transfusion: how to reduce animal usage

Basic research on the pathomechanisms of transfusion-related adverse events depends on murine transfusion models, in which leukoreduction (LR) is a prevalent standard. The commonly used neonatal LR filter (LRF) is associated with considerable animal numbers. A more efficient method would help support the guiding principles of "replacement, reduction, refinement" (3Rs). Blood from C57BL/6 and C57BL/6-Tg(UBC-GFP)30Scha/J mice was leukoreduced using (1) a neonatal LRF, (2) a syringe LRF, or (3) CD45 microbeads. Product quality was assessed according to US Food and Drug Administration (FDA) standards. White blood cell numbers were analyzed by flow cytometry; hemoglobin concentrations and hematocrit were measured and in vivo posttransfusion recoveries were determined after 2 weeks of storage. Using the neonatal filter, a LR of 99.56% was achieved with wastage of 12.4 mL in comparison to 99.68% and 1-mL hold-up volume with the syringe filter and 99.11 ± 0.24% LR and 0.1-mL wastage using microbeads. All techniques achieved FDA quality standards, apart from posttransfusion recovery rate, which was only reached by the microbeads-based technique. LR with CD45 microbeads not only reduces animal usage but also provides a more efficacious method regarding posttransfusion red blood cell recovery and, hence, provides a promising alternative to commonly used methods.

Expression of the cellular prion protein affects posttransfusion recovery and survival of red blood cells in mice.

Cellular prion protein (PrP(C) ) is expressed on various cell types including red blood cells (RBCs). The PrP(C) plays a key role in the pathogenesis of prion diseases, but its physiologic function remains unclear. PrP(C) is expressed on CD34+ hematopoietic stem cells and its expression is regulated during blood cell differentiation including the erythroid line. We investigated the role of PrP(C) in RBC survival in circulation by transfusing a mix of biotin-labeled RBCs from wild-type (WT) and PrP knockout (KO) mice to groups of recipient mice (WT and KO). The proportion of biotinylated RBCs in peripheral blood was estimated by flow cytometry. KO RBCs displayed a markedly higher first-day posttransfusion recovery but had a decreased survival in circulation when compared to WT RBCs. Similar results were obtained in all groups of transfused mice, irrespective of RBCs biotinylation level. In addition, we confirmed this finding in an analogous study using Tga20 mice overexpressing PrP(C) and KO mice of a different genetic background. Our results demonstrate that PrP(C) expression affects RBC recovery and survival in circulation.

Retrospective analysis of community hospital red blood cell recovery procedures: improved utilization needed for effectiveness.

Perioperative blood recovery (PBR) is an important component of patient blood management. We analyzed our experience providing PBR for community hospitals to determine procedure types and clinical variables associated with efficacy and cost-effectiveness. PBR cases (>25,000) from January 2008 through December 2012 were analyzed. For each procedure type, the median number of returned red blood cell units (rRBCs) and ratio of cases with at least 1 to less than 1 rRBC unit were calculated. Clinical predictors of rRBC were identified by linear and logistic regression. The overall median rRBC was 0.29 units despite median estimated blood loss (EBL) of 350 mL. Only three of 31 common procedure types had ≥1:<1 rRBC ratios near to or higher than 1. In nine of 31 common procedure types, at least 50% of cases had no rRBC return. Linear regression demonstrated significant association of rRBCs with increased EBL, longer operative duration, surgeon, PBR device type (autoLog vs. CS5), and decreasing age. EBL, autoLog use, high surgeon case volume, vascular procedures, and emergent versus elective procedures associated with higher odds of at least 1 rRBC. Discrepancy between rRBC and EBL and high percentages of cases with no rRBC suggests that PBR technique and case selection need optimization. Identification of procedure types and variables associated with PBR efficacy (≥1 rRBC) should improve utilization of PBR. Association of autoLog use with higher rRBC warrants further investigation.

Pure Red Cell Aplasia In Major ABO Mismatched Allogeneic Hematopoietic Cell Transplantation Is Associated With Severe Pancytopenia

IntroductionThe persistence of anti-donor isohemagglutinins in Major ABO mismatched allogeneic stem cell transplantation (HCT) leads to pure red cell aplasia (PRCA). In our previous report of 12 patients with PRCA, severe pancytopenia was observed in one patient who eventually had a second transplant (Aung et al. B J Haematol 2013 Mar; 160(6):798-805). Furthermore, ABO antigens are expressed on or adsorbed from plasma on granulocyte and platelets and these may be affected by isohemagglutinins. To further investigate this observation we analyzed a larger cohort of patients with PRCA to determine the frequency of pancytopenia and natural history of pancytopenia in patients with PRCA after Major ABO incompatible HCT. Patients and MethodsWe reviewed 758 patients who received a Major ABO-mismatched HCT between January 2003 and December 2012 at our institution. Pure red call aplasia was determined to be present when the bone marrow biopsy on post-transplant day 30 demonstrated absent or nearly absent erythroid precursors with absence of donor red cells on forward red cell typing of the recipient and the recipient being red cell transfusion dependent. Pancytopenia was defined as ANC < 1.5 x 109/L or requiring G-CSF, Platelets < 50 x 109/L or transfusion dependent, and PRCA with red cell transfusion dependence as above at 90 days after allogeneic SCT. Results83 patients had PRCA. Of these 16 (19%) had pancytopenia at day 90 after transplant. None of these patients had any other reason for persistent pancytopenia like CMV or other viral infection or use of drugs like ganciclovir or disease recurrence. On post-transplant day 90, median absolute neutrophil counts (ANC) was 1.01 K/UL with 15 (94%) patients having intermittent G-CSF and median platelet count was 14 KL/UL (range 6-49) with 13(81%) patients platelet transfusion dependent. All patients were red cell transfusion dependent. Of the 16 PRCA patients with pancytopenia, 2 (12%) received a second transplant due to persistent pancytopenia/graft failure and 2 (12%) relapsed. 2 (12%) patients have still not recovered their platelet counts despite red cell and ANC recovery.In the remaining 10 (63%) patients, neutropenia and thrombocytopenia resolved after resolution of PRCA. Red cell recovery occurred at a median of 226 (95-549) days post transplant, ANC recovered at median of 325 (105-1080) days post-transplant, and Platelets recovered at median of 296 (94-2738) days post-transplant. ConclusionSevere pancytopenia is frequently (19%) associated with PRCA in Major ABO incompatible HCT. Neutropenia and thrombocytopenia resolve after resolution of red cell aplasia in the majority of patients. Disclosures:Andersson:Otsuka Pharmaceuticals: Research Funding. Qazilbash:Celgene: Membership on an entity's Board of Directors or advisory committees; Millennium: Membership on an entity's Board of Directors or advisory committees. Shah:Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding.

Comparative study of automated cryopreservation of red blood cells

BackgroundStrategic blood reserves are an important component in meeting blood needs and this can be accomplished through the establishment of a frozen blood program. MethodsOne hundred units of packed RBC were glycerolized using the Haemonetics ACP 215 automated cell processor and placed in a −86 °C deep freezer for freezing and storage. Product weight, hematocrit, RBC count, WBC count and hemoglobin were recorded prior to freezing. Twenty five bags were thawed and deglycerolized after every three months starting at one year from the date of first glycerolization In addition to the earlier parameters the bags were assessed for supernatant osmolality, pH, supernatant hemoglobin, ATP levels and supernatant potassium and from these red cell recovery, percentage hemolysis, supernatant glycerol and red cell viability were estimated. All tests were repeated at the end of 7 and 14 days. ResultsThe mean red cell recovery was found to be 86.12% on Day 0 and 84% on Day 14. All the bags showed residual glycerol and pH within the acceptable limits upto Day 14. Percentage hemolysis, Mean ATP levels and mean supernatant potassium levels were within acceptable limits upto Day 14. All the units were sterile upto Day 14. ConclusionThe data in this study showed that the red cells which were glycerolized using the automated platform ACP 215, frozen at −80 °C for more than a year and deglycerolized again using the ACP 215 had excellent viability while being stored at 4 °C during the 14 days of post-thaw storage.

Comparison of multiple red cell volume methods performed concurrently in premature infants following allogeneic transfusion

Background:Study of the pathophysiology and treatment of anemia of prematurity is facilitated by direct measurement of red cell volume (RCV) utilizing microliter quantities of blood samples. Our objective was to compare concurrent measurements of multiple direct RCV methods in infants.Methods:Eighteen preterm infants receiving clinically-indicated transfusions had concurrent flow cytometric determinations of RCV and 24 h red blood cell (RBC) recovery based on donor-recipient differences of biotin–labeled RBCs (BioRBCs), Kidd antigen mismatched RBCs, and HbF positive (HbF+) RBCs. HPLC was also used to measure HbF and HbA protein concentrations for RCV determination.Results:Concurrent RCV measurements using BioRBCs (18 and 54 μg/ml), Kidd antigen, and HbF flow cytometry were not statistically different compared to RCVs measured using the reference BioRBC density (6 μg/ml). In contrast, the HbF HPLC method over estimated RCV by 45% compared to the reference method. All methods demonstrated 100% 24 h post-transfusion RBC recovery (PTR24).Conclusions:Because BioRBC, Kidd antigen, and HbF flow cytometry are safe and accurate methods requiring <10 μl of patient blood to determine RCV and PTR24 in preterm infants, they can be useful in clinical and research studies of anemia and other conditions.

Efficacy and safety of mesenchymal stromal cell treatment from related donors for patients with refractory aplastic anemia

Background aimsThis study evaluated the feasibility, safety and immunological effects of the intravenous administration of mesenchymal stromal cells (MSCs) from a related donor in patients with refractory aplastic anemia (AA). MethodsA mean of 6 × 105/kg (range, 5.0–7.1 × 105) MSCs were injected intravenously to 18 patients, including 14 patients with nonsevere AA and four patients with severe AA who were refractory to prior immunosuppressive treatment. The outcomes of patients treated with MSCs were evaluated and compared with a historic control cohort, including 18 patients with refractory AA. ResultsTwo patients had injection-related adverse events, including transient fever and headache. No major adverse events were reported during the follow-up period. An immunological analysis revealed an increased proportion of CD4+CD25+ FOXP3+regulatory T cells in peripheral mononuclear cells. Following up for 1 year, six of 18 patients (33.3%) achieved a complete response or a partial response to MSC treatment. In six patients, two achieved a complete response including a recovery of three hematopoietic cell lines after MSCs therapy at days 88 and 92, two patients achieved only a red cell recovery with hemoglobin levels >100 g/L at days 30 and 48 and two patients had only a platelet recovery with a platelet count of >60 × 109/L at days 54 and 81. In the control cohort, only one patient (5.56%) achieved a partial response during the follow-up period. ConclusionsThe data from the present study suggest that treatment with MSCs from a related donor may be a promising therapeutic strategy for patients with refractory AA. The trial has been registered at ClinicalTrials.gov: identifier NCT01305694.

Insulin-Like Growth Factor 1 Mitigates Hematopoietic Toxicity After Lethal Total Body Irradiation

Summary IGF-1 administered after exposure significantly improves survival after lethal total body irradiation through accelerating hematopoietic recovery. IGF-1 protects hematopoietic stem cells and progenitor cells from radiation-induced apoptosis and cell death. IGF-1 also enhances proliferation and differentiation of the surviving hematopoietic progenitor cells. Purpose: To investigate whether and how insulin-like growth factor 1 (IGF-1) mitigates hematopoietic toxicity after total body irradiation. Methods and Materials: BALB/c mice were irradiated with a lethal dose of radiation (7.5 Gy) and treated with IGF-1 at a dose of 100 mg/dose intravenously once a day for 5 consecutive days starting within 1 hour after exposure. Survival and hematopoietic recovery were monitored. The mechanisms by which IGF-1 promotes hematopoietic recovery were also studied by use of an in vitro culture system. Results: IGF-1 protected 8 of 20 mice (40%) from lethal irradiation, whereas only 2 of 20 mice (10%) in the saline control group survived for more than 100 days after irradiation. A single dose of IGF-1 (500 mg) was as effective as daily dosing for 5 days. Positive effects were noted even when the initiation of treatment was delayed as long as 6 hours after irradiation. In comparison with the saline control group, treatment with IGF-1 significantly accelerated the recovery of both platelets and red blood cells in peripheral blood, total cell numbers, hematopoietic stem cells, and progenitor cells in the bone marrow when measured at day 14 after irradiation. IGF-1 protected both hematopoietic stem cells and progenitor cells from radiation-induced apoptosis and cell death. In addition, IGF-1 was able to facilitate the proliferation and differentiation of nonirradiated and irradiated hematopoietic progenitor cells. Conclusions: IGF-1 mitigates radiation-induced hematopoietic toxicity through protecting hematopoietic stem cells and progenitor cells from apoptosis and enhancing proliferation and differentiation of the surviving hematopoietic progenitor cells. 2013 Elsevier Inc.

Insulin-Like Growth Factor 1 Mitigates Hematopoietic Toxicity After Lethal Total Body Irradiation

To investigate whether and how insulin-like growth factor 1 (IGF-1) mitigates hematopoietic toxicity after total body irradiation. BALB/c mice were irradiated with a lethal dose of radiation (7.5 Gy) and treated with IGF-1 at a dose of 100 μg/dose intravenously once a day for 5 consecutive days starting within 1 hour after exposure. Survival and hematopoietic recovery were monitored. The mechanisms by which IGF-1 promotes hematopoietic recovery were also studied by use of an invitro culture system. IGF-1 protected 8 of 20 mice (40%) from lethal irradiation, whereas only 2 of 20 mice (10%) in the saline control group survived for more than 100 days after irradiation. A single dose of IGF-1 (500 μg) was as effective as daily dosing for 5 days. Positive effects were noted even when the initiation of treatment was delayed as long as 6 hours after irradiation. In comparison with the saline control group, treatment with IGF-1 significantly accelerated the recovery of both platelets and red blood cells in peripheral blood, total cell numbers, hematopoietic stem cells, and progenitor cells in the bone marrow when measured at day 14 after irradiation. IGF-1 protected both hematopoietic stem cells and progenitor cells from radiation-induced apoptosis and cell death. In addition, IGF-1 was able to facilitate the proliferation and differentiation of nonirradiated and irradiated hematopoietic progenitor cells. IGF-1 mitigates radiation-induced hematopoietic toxicity through protecting hematopoietic stem cells and progenitor cells from apoptosis and enhancing proliferation and differentiation of the surviving hematopoietic progenitor cells.

The application of continuous lumbar drainage in traumatic subarachnoid hemorrhage

Patients with subarachnoid hemorrhage were randomly divided into conventional treatment group and Medtronic EDM system continued external drainage group. After treatment, two groups were compared with the cure rate during hospitalization, the incidence of hydrocephalus, headache duration, duration of disturbance of consciousness, intracranial pressure returned to normal time and cerebrospinal fluid (CSF) red blood cell recovery time. The results indicated that Medtronic EDM system continued external drainage was superior to the conventional treatment. The differences were statistically significant (P < 0.05 or P < 0.01). This can explain the use of Medtronic EDM system in continuous lumbar drainage is significantly effective in treatment for subarachnoid hemorrhage. DOI：10.3969/j.issn.1672⁃6731.2012.04.019

Surface modification of polypropylene nonwovens with LDV peptidomimetics and their application in the leukodepletion of blood products

For clinical indications and according to European standards, a depletion of the leukocytes from whole blood has to be realized before transfusion to a patient. In this study, the surface of a layer of meltblown oxygen-plasma treated polypropylene nonwoven (O(2)-PP), making part of the composition of leukodepletion filters, was modified with bioactive molecules to enhance the adhesion of leukocytes. These synthetic small molecules (called peptidomimetics) mimic the "Leu-Asp-Val" (LDV) tripeptide sequence recognized by the α(4)β(1) integrin, a receptor expressed on leukocytes. Their activity, as ligands of the α(4)β(1) integrin, was confirmed through cell adhesion assays. The peptidomimetics were covalently immobilized on O(2)-PP nonwoven via activation of the hydroxyl- and carboxyl-functions displayed on the polymer surface with trifluoro-triazine reagent, or were simply deposited on the O(2)-PP surface. The treated materials were characterized by X-ray photoelectron spectroscopy, wettability, and morphological analyses, before and after steam sterilization. Experimental filters composed of 10 layers of O(2)-PP nonwovens and a last layer modified with the peptidomimetics were evaluated, using whole blood filtration assays, for their leukodepletion efficiency, the recovery of red cells and platelets and the waste of blood, with an objective to design new filters fulfilling practical and medical criteria.

Clinical evaluation of the Sorin Xtra® autotransfusion system

The performance of the Sorin Xtra® Autotransfusion System (ATS) was studied in 62 patients undergoing coronary artery bypass grafting. Blood was collected intraoperatively and washed using three different wash sets in 4 groups. Both collected and washed blood were analysed for hemoglobin levels and hematocrit, concentrations of proteins, albumin, heparin and plasma free hemoglobin (PFH) were determined, erythrocytes, platelets and leukocytes were counted.Hematocrit measurements of the Xtra® were compared with laboratory measurements to study the accuracy of the Xtra® hematocrit sensor. In addition, the red blood cell recovery rate and elimination rates were calculated to evaluate the clinical performance of the Xtra®.The Xtra® ATS produced a volume of concentrated red blood cells with an average hematocrit from 58% to 63%, depending on the size of the bowl and the chosen default program. In all bowl sizes and programs, the Xtra® Hct-out measurement underestimated the CELL-DYN measurement by approximately 15%.The calculated recovery rates for red blood cells (RBC) in the 4 groups ranged from 86.7% to 91.6%. Elimination rates were calculated in each group for proteins (96.8-99.2%), albumin (96.4-98.7%), plasma free hemoglobin (83.6–91.2%), heparin (98.8-99.9%), platelets (82.4-94.3%) and white blood cells (28.6-42.3%).The Xtra® ATS can be appealing for its performance by producing high hematocrit levels in the washed RBC volume, while keeping RBC recovery rate at the same high level (≈ 90%) as in its predecessor, the Electa® Autotransfusion System.

Red blood cell-incompatible allogeneic hematopoietic progenitor cell transplantation

Transplantation of hematopoietic progenitor cells from red cell-incompatible donors occurs in 30-50% of patients. Immediate and delayed hemolytic transfusion reactions are expected complications of red cell-disparate transplantation and both ABO and other red cell systems such as Kidd and rhesus can be involved. The immunohematological consequences of red cell-incompatible transplantation include delayed red blood cell recovery, pure red cell aplasia and delayed hemolysis from viable lymphocytes carried in the graft ('passenger lymphocytes'). The risks of these reactions, which may be abrupt in onset and fatal, are ameliorated by graft processing and proper blood component support. Red blood cell antigens are expressed on endothelial and epithelial tissues in the body and could serve to increase the risk of GvHD. Mouse models indicate that blood cell antigens may function as minor histocompatibility antigens affecting engraftment. Similar observations have been found in early studies of human transplantation for transfused recipients, although current conditioning and immunosuppressive regimens appear to overcome this affect. No deleterious effects from the use of red cell-incompatible hematopoietic grafts on transplant outcomes, such as granulocyte and platelet engraftments, the incidences of acute or chronic GvHD, relapse risk or OS, have been consistently demonstrated. Most studies, however, include limited number of patients, varying diagnoses and differing treatment regimens, complicating the detection of an effect of ABO-incompatible transplantation. Classification of patients by ABO phenotype ignoring the allelic differences of these antigens also may obscure the effect of red cell-incompatible transplantation on transplant outcomes.

Cesium cessation? An advantage of pathogen reduction treatments

Cesium cessation? An advantage of pathogen reduction treatments

Addition of oligosaccharide decreases the freezing lesions on human red blood cell membrane in the presence of dextran and glucose

Although incubation with glucose before freezing can increase the recovery of human red blood cells frozen with polymer, this method can also result in membrane lesions. This study will evaluate whether addition of oligosaccharide (trehalose, sucrose, maltose, or raffinose) can improve the quality of red blood cell membrane after freezing in the presence of glucose and dextran. Following incubation with glucose or the combinations of glucose and oligosaccharides for 3 h in a 37 °C water bath, red blood cells were frozen in liquid nitrogen for 24 h using 40% dextran (W/V) as the extracellular protective solution. The postthaw quality was assessed by percent hemolysis, osmotic fragility, mean corpuscle volume (MCV), distribution of phosphatidylserine, the postthaw 4 °C stability, and the integrity of membrane. The results indicated the loading efficiency of glucose or oligosaccharide was dependent on their concentrations. Moreover, addition of trehalose or sucrose could efficiently decrease osmotic fragility of red blood cells caused by incubation with glucose before freezing. The percentage of damaged cell following incubation with glucose was 38.04 ± 21.68% and significantly more than that of the unfrozen cells (0.95 ± 0.28%, P < 0.01). However, with the increase of the concentrations of trehalose, the percentages of damaged cells were decreased steadily. When the concentration of trehalose was 400 mM, the percentage of damaged cells was 1.97 ± 0.73% and similar to that of the unfrozen cells ( P > 0.05). Moreover, similar to trehalose, raffinose can also efficiently prevent the osmotic injury caused by incubation with glucose. The microscopy results also indicated addition of trehalose could efficiently decrease the formation of ghosts caused by incubation with glucose. In addition, the gradient hemolysis study showed addition of oligosaccharide could significantly decrease the osmotic fragility of red blood cells caused by incubation with glucose. After freezing and thawing, when both glucose and trehalose, sucrose, or maltose were on the both sides of membrane, with increase of the concentrations of sugar, the percent hemolysis of frozen red blood cells was firstly decreased and then increased. When the total concentration of sugars was 400 mM, the percent hemolysis was significantly less than that of cells frozen in the presence of dextran and in the absence of glucose and various oligosaccharides ( P < 0.01). However, when both glucose and trehalose were only on the outer side of membrane, with increase of the concentrations of sugars, the percent hemolysis was increased steadily. Furthermore, addition of oligosaccharides can efficiently decrease the osmotic fragility and exposure of phosphatidylserine of red blood cells frozen with glucose and dextran. In addition, trehalose or raffinose can also efficiently mitigate the malignant effect of glucose on the postthaw 4 °C stability of red blood cells frozen in the presence of dextran. Finally, addition of trehalose can efficiently protect the integrity of red blood cell membrane following freezing with dextran and glucose. In conclusion, addition of oligosaccharide can efficiently reduce lesions of freezing on red blood cell membrane in the presence of glucose and dextran.