The impact of universal leukodepletion of the blood supply on hemovigilance reports of posttransfusion purpura and transfusion-associated graft-versus-host disease

Donors with repeated blood product discards for filtration problems, clots or hemolysis: Causes and follow-up

INTRODUCTION

Sanquin donor medicine department is informed when donations or their components are rejected. This can occur isolated or frequently. It is undesirable because the donations cannot be used and there may be an underlying medical cause. Based on regional approaches, a uniform procedure was developed.

METHODS

Information about whole blood, plasma- plateletpheresis donations from which one or more components were rejected for filtration time (>2 h), hemolysis or clots were extracted from blood bank information system. After rejection of two successive components or donations or total ≥3 the donor is contacted. Depending on the medical history and investigation by the family doctor, the donor carrier is re-evaluated. We looked for the causes of the discarded products and performed a survey among blood services regarding polices with discarded products.

RESULTS

One or more components from 1742 of about 2.2 million successful donations (0.08%) were rejected. The highest percentage of rejection was seen in plateletpheresis (1.5%), all for clots. No underlying medical causes were found. 24 whole blood donors were found to have sickle cell trait (SCT) and were permanently deferred. The policies for follow-up after discarded products or acceptance of SCT donors vary between the 16 blood banks. Six organizations do not follow-up donors and seven accept SCT for blood or plasma donation.

CONCLUSION

Informing donors with repeated discarded products avoids the non-use of donations. Causes of repeated discarded products can be found by follow-up of donors. The results of the survey indicate a large discrepancy in policies applied worldwide.

Post-transfusion purpura after cardiac surgery associated with veno-arterial extracorporeal membrane oxygenation

We report the case of a woman who developed post-transfusion purpura following complicated cardiac surgery requiring multiple blood product transfusions and extracorporeal life support. This case highlights the challenges of managing thrombocytopenia in patients supported with prolonged mechanical cardiovascular and renal support with ongoing blood product transfusion requirements. The differential diagnoses are broad, varied and may overlap. Whilst post-transfusion purpura is very rare, clinical signs may prompt consideration and further specific diagnostic testing. Once confirmed, management is then specific, with some aspects which are at direct variance with standard intensive care and extracorporeal life support guidelines for the management of non-specific thrombocytopenia. Consideration of the diagnosis of post-transfusion purpura early in the clinical course could help anticipate and prevent a vicious cycle of bleeding, transfusion and autoimmune-mediated platelet disruption, and may improve clinical outcomes.

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.

Adverse reactions following transfusion of blood components, with a focus on some rare reactions: reports to the International Haemovigilance Network Database (ISTARE) in 2012-2016

OBJECTIVES

The International Haemovigilance Network's (IHN) ISTARE database collects surveillance data on all adverse reactions (AR) associated with transfusion of blood and blood components, facilitating the sharing of best practice and benchmarking for improving blood safety and quality. Up to 2012 no publications discussed certain rare AR. The aim of this study is to examine ISTARE data on AR from 2012 to 2016, focusing on hypotensive reactions, post-transfusion purpura (PTP), transfusion-associated graft versus host disease (TA-GvHD), hyperkalemia and hypocalcemia.

MATERIALS AND METHODS

National Haemovigilance Systems (HVS), provided aggregate annual data on AR by type of reaction, severity, imputability to transfusion, and blood component implicated. Twenty-nine HVS provided 104 annual reports covering 107,778,290 blood units issued.

RESULTS

Among AR reported, 25% were serious, including 368 deaths. The 284 transfusion-transmitted infections included 187 bacterial infections, 84 viral and 13 parasitic or fungal; nine deaths resulted. AR related to the respiratory system transfusion-associated circulatory overload, transfusion-related acute lung injury and transfusion-associated dyspnoea accounted for 8.3% of all AR, 20.1% of serious, and 52.2% of deaths. Of 1634 rare AR, 1565 were hypotensive, 38 PTP, 17 GvHD, 9 hyperkalemia and 5 hypercalcemia. Half were serious and 16 fatalities were recorded (13 hypotensive, 2 GvHD, one PTP). Among 14 countries that reported any hypotensive AR, incidences diverged widely.

CONCLUSIONS

ARs in this group are frequently severe or life-threatening. Hypotensive AR are the most common, but may have been overlooked and counted under allergic and other AR presenting with hypotension. Compliance with the ISBT definition may be suboptimal, thus its real incidence may be higher. Data on GvHD may contribute to clarifying the role of leukodepletion with or without irradiation. ISTARE continues to be a useful surveillance tool for all transfusion AR and provides relevant insights into overlooked and rare AR, thus offering important contributions towards maximising transfusion safety.

Guideline development for prevention of transfusion-associated graft-versus-host disease: reduction of indications for irradiated blood components after prestorage leukodepletion of blood components

Transfusion-associated graft-versus-host disease (TA-GVHD) is a rare, commonly fatal complication of transfusion preventable by irradiation of blood units. The revision of the Dutch transfusion guideline addressed the question whether irradiation is still necessary if blood components are prestorage leukodepleted. We searched for published cases of TA-GVHD following transfusion of prestorage leukodepleted blood and through contacting haemovigilance systems. Six presumed cases were found, dating from 1998 to 2013. Four out of six patients had received one or more non-irradiated units despite recognised indications for irradiated blood components. In the countries providing information, over 50 million prestorage leukodepleted, non-irradiated, non-pathogen-reduced cellular components were transfused in a 10-year period. Potential benefits of lifting indications for irradiation were considered. These include reduced irradiation costs (€ 1.5 million annually in the Netherlands) and less donor exposure for neonates. Findings were presented in an invitational expert meeting. Recommendations linked to human leukocyte antigen similarity between donor and recipient or intra-uterine transfusion were left unchanged. Indications linked to long-lasting deep T-cell suppression were defined with durations of 6 or 12 months after end of treatment (e.g. autologous or allogeneic stem cell transplantation). Need for continued alertness to TA-GVHD and haemovigilance reporting of erroneous non-irradiated transfusions was emphasised.

Bestrahlung zellulärer Blutprodukte – Änderungen in den neuen Querschnitts-Leitlinien

Die transfusionsassoziierte Graft-versus-Host-Erkrankung (ta-GvHD) ist eine seltene, aber lebensbedrohliche Nebenwirkung der Transfusion zellulärer Blutprodukte, die durch restliche Lymphozyten des Blutspenders hervorgerufen wird. Risikofaktoren für eine ta-GvHD sind eine geschwächte T-zelluläre Abwehr des Patienten, eine hohe Zahl residueller Lymphozyten im Blutprodukt und eine einseitige HLA-Inkompatibilität zwischen Spender und Empfänger. Durch eine Bestrahlung zellulärer Blutkomponenten mit mindestens 25 Gray lässt sich eine ta-GvHD sicher verhindern. In der gerade erschienenen 5. Auflage der Querschnitts-Leitlinien der Bundesärztekammer zur Therapie mit Blutkomponenten und Plasmaderivaten wurden einige Indikationen zur Bestrahlung gelockert, da Erfahrungen aus Großbritannien zeigen, dass hier auch nach Transfusion unbestrahlter Blutprodukte kein Risiko für eine ta-GvHD besteht. So stellen lymphatische Neoplasien nicht mehr generell eine Bestrahlungsindikation dar, sondern nur, wenn ein Hodgkin-Lymphom oder ein schwerer T-Zell-Defekt vorliegt oder wenn bestimmte Therapien durchgeführt werden bzw. wurden (z. B. Gabe von Purinanaloga). Zu anderen Indikationen finden sich in den revidierten Querschnitts-Leitlinien erstmals Empfehlungen zur Verwendung bestrahlter Blutkomponenten: Dies betrifft z. B. hämatoonkologische Patienten unter Therapie mit ATG oder Alemtuzumab. Der Artikel fasst den aktuellen Erkenntnisstand zur ta-GvHD kurz zusammen und erläutert die Änderungen der revidierten Querschnitts-Leitlinien.

Setting up and sustaining blood and marrow transplant services for children in middle-income economies: an experience-driven position paper on behalf of the EBMT PDWP

Severe blood disorders and cancer are the leading cause of death and disability from noncommunicable diseases in the global pediatric population and a major financial burden. The most frequent of these conditions, namely sickle cell disease and severe thalassemia, are highly curable by blood or bone marrow transplantation (BMT) which can restore a normal health-related quality of life and be cost-effective. This position paper summarizes critical issues in extending global access to BMT based on ground experience in the start-up of several BMT units in middle-income countries (MICs) across South-East Asia and the Middle East where close to 700 allogeneic BMTs have been performed over a 10-year period. Basic requirements in terms of support systems, equipment, and consumables are summarized keeping in mind WHO’s model essential lists and recommendations. BMT unit setup and maintenance costs are summarized as well as those per transplant. Low-risk BMT is feasible and safe in MICs with outcomes comparable to high-income countries but at a fraction of the cost. This report might be of assistance to health care institutions in MICs interested in developing hematopoietic stem cell transplantation services and strengthening context appropriate tertiary care and higher medical education.

Double-filtered leukoreduction as a method for risk reduction of transfusion-associated graft-versus-host disease

Background

Transfusion-associated graft-versus-host disease (TA-GvHD) is caused by leukocytes, specifically T cells within a transfused blood product. Currently, the prevention of transfusion-associated graft-versus-host disease is performed by irradiation of blood products. With a sufficient reduction of leukocytes, the risk for TA-GvHD can be decreased. With consistent advances in current state-of-the-art blood filters, we herein propose that double filtration can sufficiently reduce leukocytes to reduce the risk for TA-GvHD.

Materials

Thirty RBC concentrates were filtered with leukocyte filters, followed by storage at 1–6 ^oC for 72 hours, and then a second filtration was performed. Residual leukocytes in the double-filtered RBC units (n = 30) were assessed with flow cytometric methods, and an additional assay with isolated peripheral blood mononuclear cells (PBMCs) (n = 6) was done by both flow cytometric methods and an automated hematology analyzer. Quality of the RBCs after filtration was evaluated by hematological and biochemical tests. In vitro T cell expansion was performed using anti-CD3/CD28-coated Dynabeads or anti-CD3 (OKT3). In vivo experiment for GvHD was performed by using NOD.Cg-Prkdc^scid Il2rg^tm1Wjl/SzJ (NSG) mice.

Results

Double-filtered blood products showed residual leukocyte levels below detection limits, which calculated to be below 1200–2500 cells per blood unit. In vitro expansion rate of T cells showed that 6x10³ and 1x10³ cell-seeded specimens showed 60.8±10.6 fold and 10.2±9.7-fold expansion, respectively. Cell expansion was not sufficiently observed in wells planted with 1x10² or 10 cells. In vivo experiments showed that mice injected with 1x10⁵ or more cells cause fatal GvHD. GvHD induced inflammation was observed in mice injected with 1x10⁴ or more cells. No evidence of GvHD was found in mice injected with 10³ cells.

Conclusions

Our study suggests that additional removal of contaminating lymphocytes by a second leukodepletion step may further reduce the risk for TA-GvHD.

Post-Transfusion Purpura: Current Perspectives

Post transfusion purpura (PTP) is an uncommonly reported post transfusion adverse event that can present with severe thrombocytopenia; sometimes resulting in significant bleeding and hemorrhage. Its diagnosis can be elusive given its substantial symptomatic overlap with other thrombocytopenic syndromes. Underdiagnosis and underreporting make the true incidence of disease difficult to define. While clinical suspicion is key, laboratory evidence of platelet-targeted antibodies and identification of the antigen(s) they recognize are necessary to confirm the diagnosis. A curious aspect of PTP is paradoxical destruction of both transfused and autologous platelets. Although the first case was reported over 50 years ago, this aspect of PTP pathogenesis is still not fully understood and is widely debated. Several theories exist, but conclusive evidence to support most is lacking. Despite limited understanding of disease incidence and etiology, treatment with IVIG (Intravenous Immunoglobulin) has become standard practice and can be highly effective. Although recurrence is rare, precautions should be taken if patients with a history of PTP require transfusions in the future.

Lack of persistent microchimerism in contemporary transfused trauma patients

BACKGROUND

Following transfusion, donor white blood cells (WBCs) can persist long-term in the recipient, a phenomenon termed transfusion-associated microchimerism (TA-MC). Prior studies suggest TA-MC is limited to transfusion following traumatic injury, and is not prevented by leukoreduction.

STUDY DESIGN AND METHODS

We conducted a prospective cohort study at a major trauma center to evaluate TA-MC following injury. Index samples were collected upon arrival, prior to transfusion. Follow-up samples were collected at intervals up to one year, and beyond for those testing positive for TA-MC. TA-MC was detected by real-time quantitative allele-specific polymerase chain reaction assays at the HLA-DR locus and several polymorphic insertion deletion sites screening for non-recipient alleles.

RESULTS

A total of 378 trauma patients were enrolled (324 transfused cases and 54 non-transfused controls). Mean age was 42 ± 18 years, 74% were male, and 80% were injured by blunt mechanism. Mean Injury Severity Score was 20 ± 12. Among transfused patients, the median (interquartile range) number of red cell units transfused was 6 (3,12), and median time to first transfusion was 9 (0.8,45) hours. Only one case of long-term TA-MC was confirmed in our cohort. We detected short-term TA-MC in 6.5% of transfused subjects and 5.6% on non-transfused controls.

CONCLUSIONS

In contrast to earlier studies, persistent TA-MC was not observed in our cohort of trauma subjects. Short-term TA-MC was detected, but at a lower frequency than previously observed, and rates were not significantly different than what was observed in non-transfused controls. The reduction in TA-MC occurrence may be attributable to changes in leukoreduction or other blood processing methods.

Effects of irradiation and leukoreduction on down-regulation of CXCL-8 and storage lesion in stored canine whole blood

White blood cells (WBCs) and storage period are the main factors of transfusion reactions. In the present study, cytokine/chemokine concentrations after leukoreduction (LR) and irradiation (IR) in stored canine whole blood were measured. Red blood cell storage lesion caused by IR and LR were also compared. Blood samples from 10 healthy Beagles were divided into four groups (no treatment, LR-, IR-, and LR + IR-treated). Leukocytes were removed by filtration in the LR group and gamma radiation (25 Gy) was applied in the IR group. Immunologic factors (WBCs, interleukin-6 [IL-6], C-X-C motif chemokine ligand 8 [CXCL-8], and tumor necrosis factor-alpha) and storage lesion factors (blood pH, potassium, and hemolysis) were evaluated on storage days 0, 7, 14, 21, and 28. Compared to the treated groups, IL-6 and CXCL-8 concentrations during storage were significantly higher in the control (no treatment) group. LR did not show changes in cytokine/chemokine concentrations, and storage lesion presence was relatively mild. IR significantly increased CXCL-8 after 14 days of storage, but IR of leukoreduced blood did not increase CXCL-8 during 28 days of storage. Storage lesions such as hemolysis, increased potassium, and low pH were observed 7 days after IR and storage of blood, regardless of LR. IR of leukoreduced blood is beneficial to avoid immune reactions; however, storage lesions should be considered upon storage.

A Case of Posttransfusion Purpura with Severe Refractory Thrombocytopenia but No Cutaneous Manifestations

Posttransfusion purpura is a serious adverse effect of transfusion due to HPA-antibodies. A young female was diagnosed with acute leukaemia, and treatment commenced. Severe thrombocytopenia ensued. No platelet increment was achieved despite transfusions with buffy coat, HLA-compatible, and HPA-1a negative platelets. The workup indicated the presence of anti-HPA-1a. When the diagnosis of posttransfusion purpura was sufficiently substantiated, she had experienced a fatal intracerebral haemorrhage.

Recommendations on Selection and Processing of RBC Components for Pediatric Patients From the Pediatric Critical Care Transfusion and Anemia Expertise Initiative

OBJECTIVES

To present the recommendations and supporting literature for selection and processing of RBC products in critically ill children developed by the Pediatric Critical Care Transfusion and Anemia Expertise Initiative.

DESIGN

Consensus conference series of international, multidisciplinary experts in RBC transfusion management of critically ill children METHODS:: The panel of 38 experts developed evidence-based, and when evidence was lacking, expert-based clinical recommendations as well as research priorities for RBC transfusions in critically ill children. The RBC processing subgroup included five experts. Electronic searches were conducted using PubMed, EMBASE, and Cochrane Library databases from 1980 to May 2017. Agreement was obtained using the Research and Development/UCLA Appropriateness Method. Results were summarized using the Grading of Recommendations Assessment, Development, and Evaluation method.

RESULTS

Five recommendations reached agreement (> 80%). Irradiated cellular products are recommended for children at risk of transfusion-associated graft versus host disease due to severe congenital or acquired causes of immune deficiency or when the blood donor is a blood relative. Washed cellular blood components and avoidance of other plasma-containing products are recommended for critically ill children with history of severe allergic reactions or anaphylaxis to blood transfusions, although patient factors appear to be important in the pathogenesis of reactions. For children with history of severe allergic transfusion reactions, evaluation for allergic stigmata prior to transfusion is recommended. In children with severe immunoglobulin A deficiency with evidence of antiimmunoglobulin A antibodies and/or a history of a severe transfusion reaction, immunoglobulin A-deficient blood components obtained either from an immunoglobulin A-deficient donor and/or washed cellular components is recommended.

CONCLUSIONS

The Transfusion and Anemia Expertise Initiative consensus conference developed recommendations for selection and processing of RBC units for critically ill children. Recommendations in this area are largely based on pediatric and adult case report data.

Amotosalen/UVA treatment inactivates T cells more effectively than the recommended gamma dose for prevention of transfusion-associated graft-versus-host disease

INTRODUCTION

Transfusion-associated graft-versus-host disease (TA-GVHD) is a rare complication after transfusion of components containing viable donor T cells. Gamma irradiation with doses that stop T-cell proliferation is the predominant method to prevent TA-GVHD. Treatment with pathogen inactivation methodologies has been found to also be effective against proliferating white blood cells, including T cells. In this study, T-cell inactivation was compared, between amotosalen/ultraviolet A (UVA) treatment and gamma-irradiation (2500 cGy), using a sensitive limiting dilution assay (LDA) with an enhanced dynamic range.

METHODS AND MATERIALS

Matched plasma units (N = 8), contaminated with 1 × 10⁶ peripheral blood mononuclear cells (PBMCs) per mL, were either treated with amotosalen/UVA or gamma irradiation, or retained as untreated control. Posttreatment, cells were cultured under standardized conditions. T-cell proliferation was determined by the incorporation of ³ H-thymidine and correlated with microscopic detection.

RESULTS

Range-finding experiments showed that after gamma irradiation (2500 cGy), significant T-cell proliferation could be observed at a 1 × 10⁷ cell culture density, some proliferation at 1 × 10⁶ , and none at 1 × 10⁵ cells/well. Based on these facts, a quantitative comparison was carried out between amotosalen/UVA at the highest challenge of 1 × 10⁷ PBMCs/well, and gamma irradiation at 1 × 10⁶ and 1 × 10⁵ PBMCs/well. Complete inactivation of the T cells after amotosalen/UVA treatment was observed, equivalent to greater than 6.2 log inactivation. Complete inactivation of the T cells was also observed after gamma irradiation when 1 × 10⁵ PBMCs/well were cultured (>4.2 log inactivation). Proliferation was observed when 1 × 10⁶ PBMCs/well were cultured (≤5.2 log inactivation) after gamma irradiation.

CONCLUSION

Amotosalen/UVA treatment more effectively inactivates T cells than the current standard of gamma irradiation (2500 cGy) for the prevention of TA-GVHD.

Transfusion reactions: prevention, diagnosis, and treatment

Blood transfusion is one of the most common procedures in patients in hospital so it is imperative that clinicians are knowledgeable about appropriate blood product administration, as well as the signs, symptoms, and management of transfusion reactions. In this Review, we, an international panel, provide a synopsis of the pathophysiology, treatment, and management of each diagnostic category of transfusion reaction using evidence-based recommendations whenever available.

Transfusion support issues in hematopoietic stem cell transplantation

BACKGROUND

Patients receiving hematopoietic stem cell transplantation require extensive transfusion support until red blood cell and platelet engraftment occurs. Rare but predictable complications may arise when the transplanted stem cells are incompatible with the native ABO type of the patient. Immediate and delayed hemolysis is often seen.

METHODS

A literature review was performed and the results from peer-reviewed papers that contained reproducible findings were integrated.

RESULTS

A strong body of clinical evidence has developed around the common complications experienced with ABO-incompatible hematopoietic stem cell transplantation. These complications are discussed and the underlying pathophysiology is explained. General treatment options and guidelines are enumerated.

CONCLUSIONS

ABO-incompatible hematopoietic stem cell transplantations are frequently performed. Immune-related hemolysis is a commonly encountered complication; therefore, health care professionals must recognize the signs of immune-mediated hemolysis and understand the various etiologies that may drive the process.

A systematic review of transfusion-associated graft-versus-host disease

Transfusion-associated graft-versus-host disease (TA-GVHD) is a rare complication of blood transfusion. The clinicolaboratory features of TA-GVHD and the relative contributions of recipient and component factors remain poorly understood. We conducted a systematic review of TA-GVHD reports. The HLA relationship between donor and recipient was classified as D = 0 when no donor antigens were foreign to the recipient vs D ≥ 1 when ≥1 donor antigen disparity occurred. We identified 348 unique cases. Criteria for component irradiation were met in 48.9% of cases (34.5% immune-compromised, 14.4% related-donor), although nonirradiated components were transfused in the vast majority of these (97.6%). Components were typically whole blood and red cells. When reported, component storage duration was ≤10 days in 94%, and 23 (6.6%) were leukoreduced (10 bedside, 2 prestorage, and 11 unknown). Among 84 cases with HLA data available, the category of D = 0 was present in 60 patients (71%) at either HLA class I or II loci and was more common among recipients without traditional indications for component irradiation. These data challenge the historic emphasis on host immune defects in the pathogenesis of TA-GVHD. The dominant mechanism of TA-GVHD in both immunocompetent and compromised hosts is exposure to viable donor lymphocytes not recognized as foreign by, but able to respond against, the recipient.

How is national recipient hemovigilance conducted in the United States?

A national recipient hemovigilance system was introduced in the United States in 2010, when voluntary enrollment began as part of the National Healthcare Safety Network (NHSN) Hemovigilance Module. NHSN is a secure, Web-based surveillance system operated by the Centers for Disease Control and Prevention and used by US health care facilities to report a variety of patient safety information. The Hemovigilance Module is used for comprehensive monitoring of transfusion-related adverse events. Participating facilities can utilize analytic tools available within the module to identify opportunities for enhancing transfusion safety, evaluate the effectiveness of interventions, and compare facility specific transfusion-related data to aggregate national estimates. Data may be voluntarily shared by facilities with external partners for patient safety improvement initiatives and to fulfill reporting mandates. We describe the key characteristics of the Hemovigilance Module, highlight the benefits for participating facilities, and discuss the use of reported data for establishing national estimates of transfusion-associated adverse events to identify gaps in transfusion safety and opportunities for interventions. National hemovigilance systems are essential to recognize gaps in transfusion safety and identify opportunities for interventions to improve patient safety and outcomes.

Functional inactivation of lymphocytes by methylene blue with visible light

Upon visible light excitation, MB can cause damage to pathogen nucleic acids, thereby inhibiting lymphocyte proliferation and cytokine secretion.

AABB validation study of the CDC's National Healthcare Safety Network Hemovigilance Module adverse events definitions protocol

BACKGROUND

The utility of a hemovigilance system depends on appropriate, reproducible application of system definitions. This is even more important when submissions are not reviewed by an adjudicating body. We sought to determine how participants would code adverse reactions at institutions that had or had not received training on the application of definitions used in the CDC's National Healthcare Safety Network Hemovigilance Module (HVM).

STUDY DESIGN AND METHODS

Facilities that were (11) or were not (11) submitting adverse reaction data to the HVM reviewed 36 hypothetical cases containing elements of 37 case definitions from 12 different diagnostic groups. Respondents were required to determine the type of adverse event, if any, and assign a case definition (diagnostic probability), severity, and imputability using the January 2013 HVM Surveillance Protocol definitions. Those submitting HVM data had access to an instructional slide set prepared by CDC using similar hypothetical cases. Concordance with expert analysis was determined for the two groups of respondents.

RESULTS

The frequencies of agreement with the expert assessment were not different according to prior training exposure in any of the diagnostic groups, and results were totaled across both groups. Response accuracy varied by type of categorization (adverse event type, 72.1%; match with case definition, 76.5%; severity, 69.6%; imputablity, 64.4%) and by type of adverse event.

CONCLUSION

Despite delineated definitions, considerable variability in responses was seen, and this was not reduced by the available training. This degree of inconsistency in application of the surveillance definitions could degrade the utility of comparative reports.

Transient residence of a seropositive organ is sufficient to transfer human cytomegalovirus to a seronegative recipient

Many aspects of the pathogenesis of human cytomegalovirus (HCMV) infection in liver transplantation remain unclear. This study examined the transfer of HCMV from the transient residence of a seropositive organ in seronegative recipients. All subjects receiving >1 orthotopic liver transplant (LT) were identified from an LT database. The patients of interest were HCMV-seronegative LT recipients who received their first organ from a seropositive donor, and subsequently a second LT from a seronegative donor within 30 days. Of 98 patients identified, 6 met these criteria and 4 developed viremia; in 2 cases, after the seropositive organ was in situ for 28 and 109 h. We can therefore conclude that 28 h is sufficient to allow HCMV to transmit, but the minimum time has not yet been defined.

Serious Hazards of Transfusion (SHOT) haemovigilance and progress is improving transfusion safety

The Serious Hazards of Transfusion (SHOT) UK confidential haemovigilance reporting scheme began in 1996. Over the 16 years of reporting, the evidence gathered has prompted changes in transfusion practice from the selection and management of donors to changes in hospital practice, particularly better education and training. However, half or more reports relate to errors in the transfusion process despite the introduction of several measures to improve practice. Transfusion in the UK is very safe: 2·9 million components were issued in 2012, and very few deaths are related to transfusion. The risk of death from transfusion as estimated from SHOT data in 2012 is 1 in 322 580 components issued and for major morbidity, 1 in 21 413 components issued; the risk of transfusion-transmitted infection is much lower. Acute transfusion reactions and transfusion-associated circulatory overload carry the highest risk for morbidity and death. The high rate of participation in SHOT by National Health Service organizations, 99·5%, is encouraging. Despite the very useful information gained about transfusion reactions, the main risks remain human factors. The recommendations on reduction of errors through a ‘back to basics’ approach from the first annual SHOT report remain absolutely relevant today.

Transfusion-Associated Graft Versus Host Disease in the Immunocompetent Patient

Transfusion associated-graft versus host disease (TA-GVHD) is a rare complication of blood transfusion. It carries a very high mortality rate. Although the phenomenon has been well described in immunocompromised patients, this review focuses on the immunocompetent host. Cases of TA-GVHD continue to be reported following a variety of surgical procedures, especially cardiac procedures requiring cardiopulmonary bypass. Additional risk factors for TA-GVHD include blood component transfusion in populations with limited genetic diversity, the use of directed donations from family members, and the transfusion of fresh blood. As there is no effective treatment, the focus is on prevention.

Immune modulation and lack of alloimmunization following transfusion with pathogen-reduced platelets in mice

BACKGROUND

Transfusion of allogeneic blood products can lead to alloimmunization, impacting success of subsequent transfusions and solid organ transplants. Pathogen reduction using riboflavin and ultraviolet B (UVB) light has been shown to eliminate the immunogenicity of white blood cells (WBCs) in vitro through down regulation of surface adhesion molecules, effectively blocking cell-cell conjugation and direct presentation. We sought to determine if this loss of immunogenicity is extended in vivo where indirect presentation of allogeneic antigens can occur.

STUDY DESIGN AND METHODS

BALB/cJ mice were transfused with either untreated or riboflavin and UVB-treated C57Bl/6J platelet-rich plasma (PRP) containing WBCs. Circulating alloantibody and allospecific splenocyte cytokine responses were measured.

RESULTS

Pathogen reduction of allogeneic WBC-enriched PRP using riboflavin and UVB light before transfusion prevented alloimmunization, with a loss of both alloantibody generation and priming of secondary cytokine responses ex vivo. When mice given treated transfusions were subsequently given untreated transfusions, they produced normal levels of alloantibodies but had reduced secondary cytokine responses ex vivo. This immune modulation was antigen specific and was dependent on the presence of WBCs in the treated product.

CONCLUSIONS

UVB plus riboflavin treatment of WBC-enriched PRP effectively blocks alloimmunization and modulates immune responses to subsequent exposures.

How I treat hematologic emergencies in adults with acute leukemia

Acute myeloid leukemia and acute lymphoblastic leukemia remain devastating diseases. Only approximately 40% of younger and 10% of older adults are long-term survivors. Although curing the leukemia is always the most formidable challenge, complications from the disease itself and its treatment are associated with significant morbidity and mortality. Such complications, discussed herein, include tumor lysis, hyperleukocytosis, cytarabine-induced cellebellar toxicity, acute promyelocytic leukemia differentiation syndrome, thrombohemorrhagic syndrome in acute promyelocytic leukemia, L-asparaginase-associated thrombosis, leukemic meningitis, neutropenic fever, neutropenic enterocolitis, and transfussion-associated GVHD. Whereas clinical trials form the backbone for the management of acute leukemia, emergent clinical situations, predictable or not, are common and do not readily lend themselves to clinical trial evaluation. Furthermore, practice guidelines are often lacking. Not only are prospective trials impractical because of the emergent nature of the issue at hand, but clinicians are often reluctant to randomize such patients. Extensive practical experience is crucial and, even if there is no consensus, management of such emergencies should be guided by an understanding of the underlying pathophysiologic mechanisms.