Transfusion-associated graft-versus-host disease

Case report: Two pediatric cases of long-term leukemia-free survival with relapsed acute T-lymphoblastic leukemia treated with donor CD7 CAR-T cells bridging to haploidentical stem cell transplantation

Introduction

Patients with relapsed/refractory (r/r) acute T-lymphoblastic leukemia (T-ALL) have a poor prognosis. We developed donor CD7 chimeric antigen receptor T (CAR-T) cells to salvage r/r T-ALL patients and obtained encouraging results. Patients who had not received allogeneic (allo-) hematopoietic stem cell transplantation (HSCT) before CAR-T therapy would develop pancytopenia and immunodeficiency for a long period after CD7 CAR-T therapy; therefore, allo-HSCT is needed in these patients. Here, we report two pediatric r/r T-ALL patients who received donor CD7 CAR-T bridging to allo-HSCT with leukemia-free survival (LFS) and sustained negative minimal residual disease for >2 years.

Case presentation

Patient 1 was a 10-year-old boy who visited our hospital because of a T-ALL relapse with multiple lymphadenopathies without discomfort. The patient did not achieve remission after one course of induction chemotherapy. The patient then received donor (his father) CD7 CAR-T cells and achieved complete remission (CR). Thirty days after the first CAR-T cell infusion, he received allo-HSCT, and his father was also the donor. His LFS was >3 years. Patient 2 was an 8-year-old boy who was admitted to our hospital with relapsed T-ALL with fever, cough, and mild dyspnea. He did not achieve remission after one course of induction chemotherapy; therefore, he received donor (his father) CD7 CAR-T cells and achieved CR. Twenty-six days after CAR-T cell infusion, the patient received allo-HSCT, with his father as the donor. He has survived for >2 years free of leukemia. At the last follow up, both patients were alive and presented a good quality of life.

Conclusion

The long-term survival of these two patients supports the use of CD7 CAR-T therapy bridging to allo-HSCT as an effective and safe treatment with the capacity to make r/r T-ALL a curable disease, similar to r/r acute B-lymphoblastic leukemia.

Transfusion-Associated Graft-Versus-Host Disease in Adults

Transfusion-associated graft-versus-host disease (TA-GVHD) is a rare but fatal complication of blood transfusion that usually develops two to 30 days following a blood transfusion giving rise to graft versus host disease (GVHD) clinical features that are consisting of fever, skin rash, jaundice, diarrhea, and pancytopenia. The disease is fulminant in most patients with a mortality rate of >90% of cases. The main aim of this review is to enhance awareness among medical practitioners about this fatal disease. Data were extracted manually from the main medical databases (Medline, Scopus, and Google Scholar) after the revision of selected articles and assessed for their contribution to the knowledge of TA-GVHD. TA-GVHD occurs when the viable donor T-cells in the blood or blood products attack the recipient's tissues which his/her immune system is incapable to destroy due to several reasons. The recipient's tissues that are usually involved in TA-GVHD include the liver, intestine, skin, lungs, and bone marrow. Any blood component either whole blood, packed red blood cells (RBCs), platelets, or fresh non-frozen plasma that contains viable T lymphocytes can cause TA-GVHD. Host immunodeficiency, transfusion of fresh blood, and partial human leukocyte antigen (HLA) matching between the donors and the recipients represent the major risk factors of TA-GVHD. Partial HLA matching includes immunocompetent recipients who receive blood from a first-degree relative also, seen in genetically homogenous populations because of high rates of consanguineous marriage. The diagnosis of TA-GVHD is mainly suspected based on clinical manifestations. However, a histopathological study of either skin or rectal biopsy is diagnostic. The treatment of TA-GVHD is generally not effective, unless the patient received emergency stem cell transplantation, while prevention via irradiation of blood or blood products represents the standard of care for this disease. In conclusion, medical practitioners should have a high index of suspicion for this disease. Moreover, future clinical trials targeting and comparing the outcomes of the different therapeutic options for TA-GVHD are required.

HTLV-1 infection of donor-derived T cells might promote acute graft-versus-host disease following liver transplantation

Acute graft versus host disease (aGVHD) is a rare, but severe complication of liver transplantation (LT). It is caused by the activation of donor immune cells in the graft against the host shortly after transplantation, but the contributing pathogenic factors remain unclear. Here we show that human T cell lymphotropic virus type I (HTLV-1) infection of donor T cells is highly associated with aGVHD following LT. The presence of HTLV-1 in peripheral blood and tissue samples from a discovery cohort of 7 aGVHD patients and 17 control patients is assessed with hybridization probes (TargetSeq), mass cytometry (CyTOF), and multiplex immunohistology (IMC). All 7 of our aGVHD patients display detectable HTLV-1 Tax signals by IMC. We identify donor-derived cells based on a Y chromosome-specific genetic marker, EIF1AY. Thus, we confirm the presence of CD4⁺Tax⁺EIF1AY⁺ T cells and Tax⁺CD68⁺EIF1AY⁺ antigen-presenting cells, indicating HTLV-1 infection of donor immune cells. In an independent cohort of 400 patients, we verify that HTLV-1 prevalence correlates with aGVHD incidence, while none of the control viruses shows significant associations. Our findings thus provide new insights into the aetio-pathology of liver-transplantation-associated aGVHD and raise the possibility of preventing aGVHD prior to transplantation.

Irradiation of platelets in Transfusion Medicine: risk and benefit judgments

Irradiation of platelet products is generally used to prevent transfusion-associated graft-versus-host disease (TA-GvHD) as well as transfusion-transmitted infections. As an essential prerequisite, gamma-irradiation of blood products prior to transfusion is required in patients who may develop TA-GVHD. Most studies suggest that gamma irradiation has no significant effect on the quality of platelet products; however, more recent studies have shown that the oxidative effects of gamma irradiation can lead to the induction of platelet storage lesion (PSL) and to some extent reduce the efficiency of transfused platelets. As the second widely used irradiation technique, UV-illumination was primarily introduced to reduce the growth of infectious agents during platelet storage, with the advantage that this method can also prevent TA-GvHD. However, the induction of oxidative conditions and platelet pre-activation that lead to PSL is more pronounced after UV-based methods of pathogen reduction. Since these lesions are large enough to clearly affect the post-transfusion platelet recovery and survival, more studies are needed to improve the safety and effectiveness of pathogen reduction technologies (PRTs). Therefore, pointing to other benefits of PRTs, such as preventing TA-GvHD or prolonging the shelf life of products by eliminating the possibility of pathogen growth during storage, does not yet seem to justify their widespread use due to above-mentioned effects. Even for gamma-irradiated platelets, some researchers have suggested that due to decreased 1-hour post-transfusion increments and increased risk of platelet refractoriness, their use should be limited to the patients who may develop TA-GVHD. It is noteworthy that due to the effect of X-rays in preventing TA-GvHD, some recent studies are underway to examine its effects on the quality and effectiveness of platelet products and determine whether X-rays can be used as a more appropriate and cost-effective alternative to gamma radiation. The review presented here provides a detailed description about irradiation-based technologies for platelet products, including their applications, mechanistic features, advantages, and disadvantages.

Effects of hypoxic storage on the efficacy of gamma irradiation in abrogating lymphocyte proliferation and on the quality of gamma-irradiated red blood cells in additive solution 3

BACKGROUND

Gamma irradiation of blood products is used to prevent transfusion-associated graft-versus-host disease by inhibiting the proliferation of lymphocytes that are implicated in the disease. Gamma irradiation also damages the red blood cells (RBCs). It is unknown whether hypoxia reduces the efficacy of gamma irradiation in inhibiting lymphocyte proliferation (LP). The objectives of the study were to investigate the effects of hypoxia on gamma irradiation-induced inhibition of LP and on the in vitro properties of RBCs.

MATERIALS AND METHODS

Forty-four units (300-340 ml each) of less than 8-h-old ABO-matched leukocyte reduced red cell concentrates (LR-RCC) in additive solution 3 were pooled in pairs. Peripheral blood mononuclear cells were isolated from non-leukocyte reduced RCCs and added back to the pool at a final concentration of 2 × 10⁵ /ml. The pool was divided equally into a conventional storage bag A and a hypoxic processing and storage bag B. The units were gamma-irradiated at 25Gy on day 7 for the LP experiment and on either day 7 or 14 for the RBC quality experiments. LP was measured using a limiting dilution assay, and several in vitro metrics of RBCs were measured.

RESULTS

Gamma irradiation inhibited T-lymphocyte proliferation by 4.7 × 10⁴ -fold reduction in both hypoxic and conventional storage. The in vitro metrics of RBC quality were better preserved in hypoxic storage.

DISCUSSION

T lymphocytes present in hypoxic RBC are equally susceptible to gamma irradiation as conventional storage. Hypoxic storage also reduces the deleterious effects of gamma irradiation on RBCs.

Directed Donation: Special Considerations and Review for Contemporary Clinical Practices

Background: Directed blood donation is defined as the donation of blood or its components for the purpose of transfusion into a specified individual. Directed blood donation holds historic significance, and although practices as of 2021 encourage voluntary, nonrenumerated blood donations, public interest in directed donation remains. Requests to discuss the risks and benefits of directed donations are a common inquiry for transfusion medicine, transplant, and hematology/oncology professionals. This narrative review discusses the history of directed donation and summarizes directed donation considerations in the context of modern transfusion practices. Methods: We conducted a systematic search of PubMed for published literature on the topic of directed blood donation and gathered information about its benefits and potential harms with respect to the variety of products used in transfusion medicine. Results: The drawbacks of directed donation include transfusion-transmitted infection risk, alloimmunization risk, increased transfusion-associated graft vs host disease risk, decreased expediency in treatment, and increased administrative burdens. However, a role remains for directed blood donation in specific patient populations, such as individuals with rare blood types or immunoglobulin A deficiencies, because of the difficulties in finding compatible blood for transfusion. Conclusion: Clinicians should consider the risks and benefits when discussing directed blood donations with patients and family members.

Diacetylene-Based Colorimetric Radiation Sensors for the Detection and Measurement of γ Radiation during Blood Irradiation

Blood and its cellular components are irradiated by ionizing radiation before transfusion to prevent the proliferation of viable T lymphocytes which cause transfusion associated-graft versus host disease. The immunodeficient patients undergoing chemotherapy for various malignancies are at risk of this disease. The international guidelines for blood transfusion recommend a minimum radiation exposure of 25 Gray (Gy) to the midplane of the blood bag, while a minimum dose of 15 Gy and a maximum dose of 50 Gy should be given to each portion of the blood bag. Therefore, precise dosimetry of the blood irradiator is essential to ensure the adequate irradiation of the blood components. The paper presents the fabrication of diacetylene-based colorimetric film dosimeters for the verification of irradiated doses. The diacetylene analogues are synthesized by tailoring them with different amide-based headgroups followed by their coating to develop colorimetric film dosimeters. Among all the synthesized diacetylene analogues, aminofluorene-substituted diacetylene exhibits the most significant color transition from white to blue color at a minimum γ radiation dose of 5 Gy. The quantitative study of color change is performed by the digitization of the scanned images of film dosimeters. The digital image processing of the developed film dosimeters facilitates rapid dose measurement which enables their facile implementation and promising application in routine blood irradiator dosimetry.

Apoptosis as an underlying mechanism in lymphocytes induced by riboflavin and ultraviolet light

Riboflavin plus UV light pathogen reduction technology (RF-PRT) is an effective method for inactivating donor-derived leukocytes (DDLs) in blood components. Literature data have shown that reactive oxygen species (ROS) increased in lymphocytes after RF-PRT treatment. Sustained high levels of ROS may abolish the endogenous antioxidant system, leading to damage to proteins, lipids, and nucleic acids, resulting in cell apoptosis. Nevertheless, whether riboflavin plus UV light can trigger leukocyte apoptosis remains obscure. In this study, a pool-and-split design, ABO/D-matched lymphocytes treated with RF-PRT or UV light or left untreated. After treatment, the level of ROS and intracellular calcium were measured in samples. Changes in the protein expression of cleaved PARP, Bax, and Bcl-2 and the activities of caspase-3 and caspase-9 were determined by immunoblot analysis or luminometer, respectively. Cell apoptosis was evaluated by flow cytometry. The effect of ROS on apoptosis was assessed. The RF-PRT treatment significantly augmented ROS production, intracellular calcium concentration. The pro-apoptotic proteins expression levels of Bax, but did not the anti-apoptotic protein Bcl-2, were markedly increased after the RF-PRT treatment. Furthermore, the percentage of apoptotic cells was increased in RF-PRT-treated lymphocytes compared to UV-treated cells or untreated cells. Moreover, the inhibition of ROS generation partially neutralized the apoptosis effects of riboflavin plus UV treatment. These findings revealed that RF-PRT-treated lymphocytes significantly increase the proportion of apoptotic cells by promoting ROS generation delineation of the biochemical processes influenced by RF-PRT are a necessary step to provide novel insights into the riboflavin pathogen inactivation technology.

Clinical-scale production of cGMP compliant CD3/CD19 cell-depleted NK cells in the evolution of NK cell immunotherapy at a single institution

BACKGROUND

Allogeneic natural killer (NK) cell adoptive immunotherapy is a growing therapeutic option for patients. Clinical-scale production of NK cells using immunomagnetic selection complies with current good manufacturing practices (cGMPs) and allows for closed-system, automated purification. We report our experience with CD3/CD19 cell-depleted (CD3/CD19_dep ) NK cell production and compare to previous methods of CD3 cell depletion and CD3 cell depletion/CD56 cell enrichment.

STUDY DESIGN AND METHODS

Nonmobilized mononuclear cells collected by apheresis were incubated with anti-CD3/anti-CD19 microbeads and depleted in an automated cell selection system (CliniMACS, Miltenyi). The NK cell-enriched products were incubated overnight in interleukin (IL)-2 or IL-15, washed, and resuspended prior to lot release testing and infusion.

RESULTS

Since 2010, 94 freshly infusible CD3/CD19_dep NK cell products were manufactured in support of eight clinical trials. Sixty-six products were incubated in IL-2 and 28 products in IL-15. Processing resulted in a mean NK cell recovery of 74% and viability of 95.8%; NK cells, T cells, B cells, and monocytes accounted for 47%, 0.2%, 0.08%, and 49% of the final products, respectively. Seven products required dose adjustments to meet lot release. The specification for purity changed throughout the evolution of manufacturing. IL-2 or IL-15 activation enhanced in vitro cytotoxicity compared to preactivated cells. There was no difference in final product composition or cytotoxicity between cytokine cohorts.

CONCLUSION

Clinical-scale/cGMP production of NK cells using CD3/CD19 cell-depletion effectively minimized T-cell and B-cell contamination in a single manipulation without compromise to NK-cell recovery. Cytokine activation increased in vitro cytotoxicity compared to column-depleted, preactivated NK cells.

Quality of irradiated and non-irradiated plateletpheresis concentrates stored in platelet additive solution

INTRODUCTION

Platelet additive solutions (PAS) allow to maintain platelet storage properties in platelet concentrates (PCs). The aim of the present study was to evaluate the in-vitro quality of irradiated and non-irradiated PCs, suspended in PAS, over a storage period of 6 days.

METHODS

Plateletpheresis donors fulfilling current eligibility criteria underwent plateletpheresis with the MCS+ blood cell separator. The PAS SSP+ was used to store platelets (PLT) for up to 6 days. Aliquots were drawn from the PCs after collection, at day 4, 5 and 6 of storage. A battery of tests was performed to analyse the quality of the PCs: PLT count, mean PLT volume (MPV), PLT activation marker CD 62, swirl, RBC and WBC contamination, pH, citrate, glucose, lactate and lactate dehydrogenase.

RESULTS

An average of 2.53 ± 0.21 × 10¹¹ PLT were collected in a product volume of 231 ± 5 mL in irradiated and 233 ± 6 mL in non-irradiated PCs, respectively. RBC- and WBC-contamination were within the allowed ranges. Δ CD62 steadily decreased in irradiated and non-irradiated PCs while the pH was well maintained over storage time. Glucose and lactate levels of irradiated and non-irradiated PCs showed characteristic pattern of PC storage within acceptable ranges.

CONCLUSION

Our data demonstrate that parameters of PC quality were well maintained over a storage period of 6 days using PAS. Irradiation had no impact on the quality of PCs. The product quality of irradiated and non-irradiated PCs met national and European guidelines.

Blood product utilization in human upper-extremity transplantation: challenges, complications, considerations, and transfusion protocol conception

BACKGROUND

Upper-extremity transplantation (UET) is a reality. Immunologic, functional, and graft survival outcomes have been encouraging. However, these complex reconstructions have unique considerations that pose distinct challenges. Transplant programs have reported morbidity and mortality due to significant intraoperative blood losses, but similar data are scant during other phases of recovery. We report experience from two centers on complete blood component demands and utilization with UET.

STUDY DESIGN AND METHODS

Inpatient medical records of UET recipients from intraoperative (time from initiation of transplant surgery to exit from the operative suite) and postoperative (exit from the operative suite to discharge from the hospital) phases were retrospectively reviewed.

RESULTS

Six patients received various UETs and mean (±SD) postoperative hospital stay was 46 (±14.4) days. Mean (±SD) intraoperative blood unit utilization was 14.8 (±10.2) red blood cells (RBCs), 10.5 (±11.8) plasma, 0.8 (±1.2) platelets (PLTs), and 0.3 (±0.8) cryoprecipitate units. Mean postoperative blood unit utilization was 9.3 (±10.4) RBCs, 5.3 (±6.7) plasma, 1.2 (±2.0) PLTs, and 0.7 (±1.6) cryoprecipitate units. Both intraoperative and postoperative blood utilization for unilateral versus bilateral transplant were different, but not significantly so. However, total inpatient blood use in bilateral transplants was significantly greater than in unilateral transplants.

CONCLUSION

Substantial blood loss may occur in UET and require transfusion of many blood components, primarily RBCs and plasma. We propose an UET transfusion protocol and suggest that centers preparing to perform these transplants should actively engage the transfusion medicine service to ensure availability and access to appropriate blood components for the entire hospitalizations of these unique patients.

GADD45α is involved in the apoptosis of lymphocytes induced by riboflavin and ultraviolet light

BACKGROUND

Riboflavin plus ultraviolet (UV) pathogen reduction technology (RF-PRT) is an effective method for inactivating the residual white blood cells (WBCs) in blood components. The RF-PRT system for platelets is known to activate many signaling pathways, including p38 and NF-κB. Nevertheless, proteomic studies in WBCs after riboflavin plus UV treatment requires further analysis.

STUDY DESIGN AND METHODS

ABO/D-matched lymphocytes were pooled, split, and treated with RF-PRT or UV light or left untreated. After treatment, cell apoptosis was measured. In addition, cell proliferation and the cycle distribution were evaluated upon stimulation with phytohemagglutinin. The changes in the protein expression levels of growth arrest and DNA damage-inducible (GADD)45α, p38, and c-Jun N-terminal kinase (JNK) were determined by Western blotting. The effect of GADD45α, p38, and JNK on apoptosis was assessed.

RESULTS

RF-PRT significantly inhibited proliferation and induced G1 arrest in lymphocytes. Furthermore, the percentage of apoptotic cells was increased in RF-PRT-treated lymphocytes compared to UV-treated cells or untreated cells, associated with the up regulation of GADD45α expression. Consistent with these observations, the inhibition of GADD45α expression partially counteracted the effects of riboflavin plus UV treatment. The p38 and JNK signaling pathways were activated by GADD45α in RF-PRT-treated lymphocytes.

CONCLUSIONS

These data revealed that RF-PRT effectively inhibited proliferation and induced apoptosis of lymphocytes by promoting GADD45α expression, which subsequently activates p38 and JNK signaling pathways.

In vivo engineering of mobilized stem cell grafts with the immunomodulatory drug FTY720 for allogeneic transplantation

The immunological attributes of stem cell grafts play an important role in the outcome of allogeneic stem cell transplants. Currently, ex vivo manipulation techniques such as bulk T-cell depletion or positive selection of CD34(+) cells are utilized to improve the immunological attributes of grafts and minimize the potential for graft-versus-host disease (GvHD). Here, we demonstrate a novel graft engineering technique, which utilizes the immunomodulatory drug FTY720 for in vivo depletion of naïve T (TN ) cells from donor G-CSF-mobilized grafts without ex vivo manipulation. We show that treatment of donor mice with FTY720 during mobilization depletes grafts of TN cells and prevents lethal GvHD following transplantation in a major mismatch setting. Importantly, both stem cells and NK cells are retained in the FTY720-treated grafts. FTY720 treatment does not negatively affect the engraftment potential of stem cells as demonstrated in our congenic transplants or the functionality of NK cells. In addition, potentially useful memory T cells may be retained in the graft. These findings suggest that FTY720 may be used to optimize the immunological attributes of G-CSF-mobilized grafts by removing potentially deleterious TN cells which can contribute to GvHD, and by retaining useful cells which can promote immunity in the recipient.

Benefit of STR-based chimerism analysis to identify TA-GVHD as a cause of death: Utility of various biological specimens

Transfusion-associated graft-versus-host disease (TA-GVHD) is a rare condition. It can occur after blood transfusion in immune-compromised and occasionally even in immune-competent patients, and is associated with a mortality rate of >90%. The diagnosis of TA-GVHD is often delayed because of its non-specific clinical features. A case of an immune-competent child who developed TA-GVHD is reported here. DNA profiling (short tandem repeat analysis), a technique that has a wide application in forensic medicine, was performed to detect the presence of donor cells in this patient. The findings suggest that more studies are needed with this tool, and the diagnostic potential of using other multiple biological specimens for DNA profiling such as the hair follicle and buccal swab should be evaluated. This is the first case report where the donor's DNA fingerprinting pattern was substantiated from a patient's hair follicle sample. Chimerism was also present in the blood and buccal swab specimens.

Use of non-irradiated blood components in Campath (alemtuzumab)-treated renal transplant patients

BACKGROUND

The prevention of transfusion-associated graft-versus-host disease (TA-GvHD) through the irradiation of components is key as there is no effective treatment. Universal leucodepletion reduces but may not eliminate TA-GvHD; therefore, irradiation is still recommended. In 2010, Campath (alemtuzumab) was added as an indication for irradiation but was not implemented everywhere.

OBJECTIVES

To identify any cases of TA-GvHD in our Campath-conditioned renal transplant patients, who were transfused with non-irradiated components.

METHODS

Retrospective study of Campath-conditioned renal transplant patients transfused with non-irradiated components. In those transfused up to 9 months following Campath who survived to 1-year follow-up, TA-GvHD was excluded. For patients not followed-up for a full year, we reviewed medical records for features of TA-GvHD. For patients transfused after 9 months following Campath, survival of at least 3 months following last transfusion excluded TA-GvHD.

RESULTS

Six hundred and forty-seven Campath-conditioned renal transplant patients were transfused; 616 were transfused within 9 months following Campath; 601 were alive at 1 year, excluding TA-GvHD. Twelve died and three were not followed-up for a full year, but a review of medical records excluded TA-GvHD. The 31 patients transfused 9 months or longer following Campath were all alive 6 months following the last transfusion, excluding TA-GvHD.

CONCLUSIONS

Despite receiving non-irradiated components, none of the 647 Campath-conditioned renal transplant patients developed TA-GvHD. Further reviews to replicate our data could enable change to guidance, at least in UK where components are leucodepleted, as an unnecessary requirement for irradiated components has both clinical delay and cost implications.

Enumeration of residual white blood cells in leukoreduced blood products: Comparing flow cytometry with a portable microscopic cell counter

Transfusion of blood components is potentially associated to the risk of cell-mediated adverse events and current guidelines require a reduction of residual white blood cells (rWBC) below 1 × 10(6) WBC/unit. The reference method to enumerate rare events is the flow cytometry (FCM). The ADAM-rWBC microscopic cell counter has been proposed as an alternative: it measures leukocytes after their staining with propidium iodide. We have tested the Adam-rWBC for the ability to enumerate rWBC in red blood cells and concentrates. We have validated the flow cytometry (FCM) for linearity, precision accuracy and robustness and then the ADAM-rWBC results have been compared with the FCM. Our data confirm the linearity, accuracy, precision and robustness of the FCM. The ADAM-rWBC has revealed an adequate precision and accuracy. Even if the Bland-Altman analysis of the paired data has indicated that the two systems are comparable, it should be noted that the rWBC values obtained by the ADAM-rWBC were significantly higher compared to FCM. In conclusion, the Adam-rWBC cell counter could represent an alternative where FCM technology expertise is not available, even if the risk that borderline products could be misclassified exists.

Evaluation of the effectiveness of packed red blood cell irradiation by a linear accelerator

Irradiation of blood components with ionizing radiation generated by a specific device is recommended to prevent transfusion-associated graft-versus-host disease. However, a linear accelerator can also be used in the absence of such a device, which is the case of the blood bank facility studied herein. In order to evaluate the quality of the irradiated packed red blood cells, this study aimed to determine whether the procedure currently employed in the facility is effective in inhibiting the proliferation of T lymphocytes without damaging blood components.

The proliferation of T lymphocytes, plasma potassium levels, and the degree of hemolysis were evaluated and compared to blood bags that received no irradiation. Packed red blood cell bags were irradiated at a dose of 25 Gy in a linear accelerator. For this purpose, a container was designed to hold the bags and to ensure even distribution of irradiation as evaluated by computed tomography and dose-volume histogram.

Irradiation was observed to inhibit the proliferation of lymphocytes. The percentage of hemolysis in irradiated bags was slightly higher than in non-irradiated bags (p-value >0.05), but it was always less than 0.4% of the red cell mass. Although potassium increased in both groups, it was more pronounced in irradiated red blood cells, especially after seven days of storage, with a linear increase over storage time.

The findings showed that, at an appropriate dosage and under validated conditions, the irradiation of packed red blood cells in a linear accelerator is effective, inhibiting lymphocyte proliferation but without compromising the viability of the red cells.

Adverse events related to blood transfusion

The acute blood transfusion reactions are responsible for causing most serious adverse events. Awareness about various clinical features of acute and delayed transfusion reactions with an ability to assess the serious reactions on time can lead to a better prognosis. Evidence-based medicine has changed today's scenario of clinical practice to decrease adverse transfusion reactions. New evidence-based algorithms of transfusion and improved haemovigilance lead to avoidance of unnecessary transfusions perioperatively. The recognition of adverse events under anaesthesia is always challenging. The unnecessary blood transfusions can be avoided with better blood conservation techniques during surgery and with anaesthesia techniques that reduce blood loss. Better and newer blood screening methods have decreased the infectious complications to almost negligible levels. With universal leukoreduction of red blood cells (RBCs), selection of potential donors such as use of male donors only plasma and restriction of RBC storage, most of the non-infectious complications can be avoided.

Transfusion-associated graft versus host disease (TAGVHD)--with reference to neonatal period

Transfusion-associated graft versus host disease [TAGVHD] results from the engraftment of transfused immuno-competent cells in blood transfusion recipients, whose immune system is unable to reject them. All blood products containing viable, immuno-competent T cells have been implicated in TAGVHD. Presence of a "one-way HLA match between donor and recipient" is associated with a significantly increased risk of TAGVHD. Though sharing of haplotype is the most probable explanation, it is far from adequate. Since TAGVHD is not seen in patients with AIDS, and an acute GVHD-like syndrome has been noted in some identical twins and autologous (self) transplants, some other processes, possibly of an "autoimmune" nature are responsible for TAGVHD. Most of the cases have been reported from Japan. This clustering in space and time is rather intriguing. We offer here alternative hypothesis. Foetal and then neonatal lymphocytes exhibit tolerance towards donor cytotoxic T lymphocytes; and consequently very few cases of TAGVHD have been reported in neonates than expected. This tolerance is a part of altered immunology of pregnancy. We feel that it is possible to use maternal blood for transfusion to her newborn baby by following certain protocol and procedure and TAGVHD is no barrier.

Blood product transfusions and reactions

Blood product transfusions are an essential component of the practice of emergency medicine. From acute traumatic hemorrhage to chronic blood loss necessitating transfusion for symptomatic anemia, familiarity with individual blood products and their indications for transfusion is an essential tool for every emergency physician (EP). Although the focus of this article is primarily on the transfusion of red blood cells, many of the concepts are applicable to the transfusion of all blood products. EPs must be fully familiar with both the individual blood components and the potential reactions and complications of these transfusions.

Blood transfusions in cardiac surgery: indications, risks, and conservation strategies

Although red blood cell (RBC) transfusions are frequently used in cardiac operations, an increasing amount of data has demonstrated deleterious consequences. Consequently, the appropriate use of this limited resource is unclear. In this review, we discuss the relationship between anemia and the outcomes of cardiac surgical procedures, the risks associated with RBC transfusion, and the impact of blood transfusions on mortality and morbidity after cardiac operations. The review concludes with a discussion of randomized trials comparing restrictive versus liberal transfusion strategies and a consideration of blood conservation techniques.

Acute graft versus host disease after orthotopic liver transplantation

Graft versus host disease (GVHD) is an uncommon complication after orthotopic liver transplantation (OLT) with an incidence of 0.1–2%, but an 80–100% mortality rate. Patients can present with skin rashes, diarrhea, and bone marrow aplasia between two to eight weeks after OLT. Diagnosis of GVHD is made based on clinical and histologic evidence, supported by chimerism studies showing donor HLA alleles in the recipient bone marrow or blood. Several therapeutic approaches have been used for the management of GVHD after OLT including increased immunosuppression, decreased immunosuppression, and cellular therapies. However, success rates have been low, and new approaches are needed.

T-cell receptor gene therapy targeting melanoma-associated antigen-A4 inhibits human tumor growth in non-obese diabetic/SCID/γcnull mice

Adoptive cell therapy with lymphocytes that have been genetically engineered to express tumor-reactive T-cell receptors (TCR) is a promising approach for cancer immunotherapy. We have been exploring the development of TCR gene therapy targeting cancer/testis antigens, including melanoma-associated antigen (MAGE) family antigens, that are ideal targets for adoptive T-cell therapy. The efficacy of TCR gene therapy targeting MAGE family antigens, however, has not yet been evaluated in vivo. Here, we demonstrate the in vivo antitumor activity in immunodeficient non-obese diabetic/SCID/γc(null) (NOG) mice of human lymphocytes genetically engineered to express TCR specific for the MAGE-A4 antigen. Polyclonal T cells derived from human peripheral blood mononuclear cells were transduced with the αβ TCR genes specific for MAGE-A4, then adoptively transferred into NOG mice inoculated with MAGE-A4 expressing human tumor cell lines. The transferred T cells maintained their effector function in vivo, infiltrated into tumors, and inhibited tumor growth in an antigen-specific manner. The combination of adoptive cell therapy with antigen peptide vaccination enhanced antitumor activity, with improved multifunctionality of the transferred cells. These data suggest that TCR gene therapy with MAGE-A4-specific TCR is a promising strategy to treat patients with MAGE-A4-expressing tumors; in addition, the acquisition of multifunctionality in vivo is an important factor to predict the quality of the T-cell response during adoptive therapy with human lymphocytes.

Risks of transfusion

Each year, more than 4 million patients receive a blood transfusion in the United States to control symptoms associated with anemia, coagulopathy, thrombocytopenia, or some combination thereof. In each of these cases, the physician and the patient must weigh the potential benefits of the transfusion along with the associated risks. To assess accurately the risk:benefit ratio and to discuss this with the patient, the physician must be familiar with the range of adverse transfusion outcomes and the current estimates of their frequency. Most important, during the past decade the risk profile of transfusion has changed significantly. Transfusion-transmitted disease, although still a rare outcome of transfusion, is no longer an overriding concern in transfusion safety considerations; however, risks such as hemolysis, transfusion-related lung injury, and anaphylaxis continue to represent significant concerns and are relatively more common than the transmission of infectious diseases after transfusion. Against this background, the development of a national hemovigilance system, designed to evaluate more accurately transfusion adverse outcomes in the United States, will require greater precision and reliability in the assessment of adverse transfusion outcomes by clinicians if the proposed benefits of this system are to be realized.

Fatal transfusion-associated graft-versus-host disease with concomitant immune hemolysis in a group A combat trauma patient resuscitated with group O fresh whole blood

Transfusion-associated graft-versus-host disease (TA-GVHD) is a rare but well-established fatal complication of blood transfusion. It can occur in immunocompetent patients when they receive transfusions from human leukocyte antigen-haploidentical donors who have lymphocytes with antigens that are not recognized as foreign by the host, but that recognize the host's tissues as foreign. It is generally viewed as a T-cell-mediated process. Graft-induced immune hemolysis or passenger lymphocyte syndrome is a well-described complication of marrow or solid organ transplantation in which immune competent donor B cells produce alloantibodies to recipient red blood cell (RBC) antigens and cause hemolysis of the recipient's RBCs. It is generally considered as a separate process from GVHD, although it could be considered a type of GVHD. Despite the theoretical possibility of both a B-cell and T-cell component to TA-GVHD, detection of a humoral antibody in cases of acute TA-GVHD has not been described. We describe the clinical course and laboratory evaluation of a group A combat trauma patient who was acutely resuscitated with group O fresh whole blood and RBCs and group AB fresh-frozen plasma who experienced the onset of the clinical symptoms of TA-GVHD as well as the onset of hemolysis due to donor-derived anti-A in his plasma 11 days after transfusion.

Immune recognition of transplacentally acquired lymphoid allografts selects for increased major histocompatibility polymorphism

The extreme polymorphism of mammalian major histocompatibility (MHC) Class I and Class II alleles has been attributed to inbreeding avoidance, heterozygote advantage and pathogen driven selection for rare MHC alleles. However, MHC alleles can be classified into a limited number of allele supertypes based on the specificity of their peptide binding grooves (about 10 supertypes in the case of human MHC Class I alleles). The paradox is that if antigen presentation can be accomplished by a limited number of binding groove motifs, why are these loci so polymorphic? An unexplored driver of this complexity may be selection pressure to enhance the antigenicity and immune recognition of transplacentally acquired lymphoid allografts during pregnancy. The exchange of lymphoid cells between mother and fetus probably occurs in all pregnancies and may lead to fetal and/or maternal lymphoid microchimerism, a known cause of autoimmune disease. Natural selection may have favoured increased polymorphism at MHC Class I and Class II loci in order to improve immune surveillance of these cells and thereby reduce the incidence of maternal and fetal autoimmune disease. At the same time, selection may have favoured the retention of a limited set of allele supertypes which optimally present immunodominant antigens.

Immunotherapy through T-cell receptor gene transfer induces severe graft-versus-host disease

Evaluation of: Bendle GM, Linnemann C, Hooijkaas AI et al.: Lethal graft-versus-host disease in mouse models of T cell receptor gene therapy. Nat. Med. 16(5), 565-570 (2010). Graft-versus-host disease is commonly associated with allogeneic hematopoietic cell transplantation, as it is the major complication. This article reports that, after immunotherapy with lymphocytes that have been transduced with T-cell receptor (TCR) genes of known specificity, graft-versus-host disease can occur through TCR gene transfer. This autoimmune pathology occurs through the formation of self-reactive TCRs as a result of one chain of the transduced TCR cross-pairing with an endogenous TCR. Certain adjustments in the design of gene therapy vectors may help reduce the risk of such autoimmune phenomena.

White blood cell inactivation after treatment with riboflavin and ultraviolet light

Functional white blood cells (WBCs) in blood components may be responsible for a number of adverse transfusion effects, including transfusion-associated graft-versus-host disease (TA-GVHD), alloimmunization, and alloimmune platelet (PLT) refractoriness. TA-GVHD occurs when functional lymphocytes are transfused into a patient who is unable to mount an immune response to the human leukocyte antigen (HLA) due to HLA compatibility or immunosuppression. Alloantibodies against HLA antigens on donor WBCs and PLTs are the major cause of refractoriness to PLT transfusions in patients receiving repeated blood transfusions. Attempts to reduce these undesirable effects have included leukoreduction filters and gamma irradiation. Studies have shown that exposure of PLT concentrates to riboflavin and light (Mirasol pathogen reduction technology [PRT], CaridianBCT Biotechnologies) causes irreparable modifications of nucleic acids that result in inactivation of a wide range of pathogens as well as inhibition of the immunologic responses mediated by WBCs present in PLT concentrates. This article summarizes these studies and also reports on additional findings from the Trial to Reduce Alloimmunization to Platelets (TRAP) and Mirasol Clinical Evaluation (MIRACLE) trials. Data from in vitro studies and this clinical trial suggest that PRT treatment may be as effective as gamma irradiation in preventing TA-GVHD and more effective than leukoreduction in preventing alloimmunization.

Reducing costs in flow-cytometric counting of residual white blood cells in blood products: utilization of a single-platform bead-free flow-rate calibration method

BACKGROUND

Commercial flow-cytometric methods for counting residual white blood cells (rWBCs) in leukoreduced blood products use calibration beads for estimation of the measured sample volume. A bead-free flow-rate calibration method is developed and validated.

STUDY DESIGN AND METHODS

The analyzed volume was calculated by acquisition time (ACQ). Twenty-nine spiking series of red blood cell (RBC) or platelet (PLT) products were prepared containing levels ranging from 0.08 × 10(6) up to 2048 × 10(6) WBCs/L. Nearly WBC-free triple-leukofiltered RBCs or PLT concentrates (PCs) served as background. Propidium iodide (PI) was used to identify rWBCs. Five RBC series were compared against a commercially available kit (LeukoSure, Beckman Coulter). Routine capabilities were tested on 41 RBC and 92 PC samples of two independent transfusion services.

RESULTS

The lower detection limit in RBC was 0.08 × 10(6) rWBCs/L for ACQ and 0.16 for LeukoSure. Criteria for linearity, accuracy, and precision were fulfilled within the range of 0.5 × 10(6) to 512 × 10(6) WBCs/L. For PCs, all these criteria were fulfilled between 0.5 × 10(6) and 32 × 10(6) rWBCs/L (lower detection limit of 0.25) for PI. ACQ and LeukoSure agreed sufficiently (81%) when tested on routine RBCs or PCs.

CONCLUSION

A residual WBC count of fewer than 0.5 × 10(6) WBCs/L can be accurately counted using the ACQ approach at a total reagent cost of less than 0.5€ per sample.

Transfusion associated graft versus host disease following whole blood transfusion from an unrelated donor in an immunocompetent patient

Graft-versus-host disease (GVHD) is a well-known complication of allogeneic bone marrow transplantation. Transfusion associated graft-versus-host disease (TA-GVHD) is much less common and nearly uniformly fatal complication of blood transfusion. The risk factors underlying the development of TA- GVHD are incompletely defined, but it is commonly seen in individuals with congenital or acquired immunodeficiency, transfusions from blood relatives, intrauterine transfusions and HLA-matched platelet transfusions. Diagnosis of TA-GVHD may be difficult at a time due to rarity in occurrence and overlapping clinical features with various infections and drug reactions. We describe a case of transfusion-associated GVHD that occurred after transfusion of whole blood from unrelated donor in an immunocompetent patient.

Transfusion associated graft versus host disease in an immunocompetent individual following coronary artery bypass grafting

Transfusion associated graft versus host disease (TA-GVHD) is a rare but commonly fatal complication of transfusion of cellular blood products, which usually occurs in immunosuppressed individuals following transfusion and subsequent engraftment of viable T lymphocytes. Very rarely it may arise in apparently immunocompetent individuals. The clinical syndrome consists of fever, skin rash, diarrhoea, hepatic dysfunction, and bone marrow aplasia. The outcome is nearly always fatal. We present here a case report of fatal TA-GVHD in a “presumed” immunocompetent patient, post coronary artery bypass grafting surgery after transfusion of blood products. The patient died 24 days after transfusion.

There is a perceived increased risk of TA-GVHD following bypass grafting and other surgical procedures where cardiopulmonary bypass is required. TA-GVHD is probably underreported and the incidence is felt to be too low to warrant routine irradiation of cellular products for this group of patients. Clinicians, pathologists, and transfusion centers should be aware of this rare but devastating complication of blood transfusion after cardiac surgery.

Lethal graft-versus-host disease in mouse models of T cell receptor gene therapy

The transfer of T cell receptor (TCR) genes can be used to induce immune reactivity toward defined antigens to which endogenous T cells are insufficiently reactive. This approach, which is called TCR gene therapy, is being developed to target tumors and pathogens, and its clinical testing has commenced in patients with cancer. In this study we show that lethal cytokine-driven autoimmune pathology can occur in mouse models of TCR gene therapy under conditions that closely mimic the clinical setting. We show that the pairing of introduced and endogenous TCR chains in TCR gene-modified T cells leads to the formation of self-reactive TCRs that are responsible for the observed autoimmunity. Furthermore, we demonstrate that adjustments in the design of gene therapy vectors and target T cell populations can be used to reduce the risk of TCR gene therapy-induced autoimmune pathology.

Acquired immune mediated aplastic anemia: is it antineoplastic?

There is increasing evidence that autoimmunity can inhibit growth of solid tumors. We propose that anti-tumor activity also operates in autoimmunity against hematopoietic stem cells in acquired aplastic anemia (AA). Reduction/dysfunction of regulatory T cells (T(REG)) in AA - rather than being the primary event - could be a response to insufficient or failing anti-tumor reactivity in predisposed individuals, causing elimination of tumor cells and collateral damage to adjacent normal hematopoietic tissue. This pathophysiological mechanism could also apply to otherwise unexplained pancytopenic syndromes which frequently occur in patients with leukemia and lymphoma and non-hematological malignancies. Observations supporting an anti-tumor effect of marrow hypoplasia/aplasia are presented and illustrated with case reports. The conclusion would be that pancytopenia occurring in AA or in AA-like syndromes reflects an ongoing immune reaction against underlying malignancy or infection.

Reconstituted fresh whole blood improves clinical outcomes compared with stored component blood therapy for neonates undergoing cardiopulmonary bypass for cardiac surgery: a randomized controlled trial

OBJECTIVE

This study compared the effects of reconstituted fresh whole blood against standard blood component therapy in neonates undergoing cardiac surgery.

METHODS

Patients less than 1 month of age were randomized to receive either reconstituted fresh whole blood (n = 31) or standard blood component therapy (n = 33) to prime the bypass circuit and for transfusion during the 24 hours after cardiopulmonary bypass. Primary outcome was chest tube drainage; secondary outcomes included transfusion needs, inotrope score, ventilation time, and hospital length of stay.

RESULTS

Patients who received reconstituted fresh whole blood had significantly less postoperative chest tube volume loss per kilogram of body weight (7.7 mL/kg vs 11.8 mL/kg; P = .03). Standard blood component therapy was associated with higher inotropic score (6.6 vs 3.3; P = .002), longer ventilation times (164 hours vs 119 hours; P = .04), as well as longer hospital stays (18 days vs 12 days; P = .006) than patients receiving reconstituted fresh whole blood. Of the different factors associated with the use of reconstituted fresh whole blood, lower platelet counts at 10 minutes and at the end of cardiopulmonary bypass, older age of cells used in the prime and throughout bypass, and exposures to higher number of allogeneic donors were found to be independent predictors of poor clinical outcomes.

CONCLUSIONS

Reconstituted fresh whole blood used for the prime, throughout cardiopulmonary bypass, and for all transfusion requirements within the first 24 hours postoperatively results in reduced chest tube volume loss and improved clinical outcomes in neonatal patients undergoing cardiac surgery.