Survey of Institutional Policies for Provision of "CMV-Safe" Blood in Ontario

A Centre-Based Comparison of Double vs Single Prevention Strategy on Transfusion Transmitted-Cytomegalovirus in At-Risk Haemopoietic stem cell transplant Patients and a State Survey on CMV-Seronegative Ordering Practices

BACKGROUND AND OBJECTIVES

Universal leucocyte depletion reduces the risk of transfusion transmitted Cytomegalovirus; however, many clinicians still prescribe Cytomegalovirus seronegative units. Our retrospective study aims to confirm the low risk of transfusion transmitted Cytomegalovirus with leucocyte depletion alone and demonstrate the ongoing variability in Cytomegalovirus seronegative transfusion prescribing.

MATERIALS AND METHODS

Over a 9 year period (7/2009-7/2018), occurrences of transfusion transmitted Cytomegalovirus in Cytomegalovirus seronegative donor/recipient haemopoietic stem cell transplant pairs were compared at one allogeneic haemopoietic stem cell transplant centre providing Cytomegalovirus seronegative blood products and leucocyte depletion (double prevention) versus another providing leucocyte depletion only (single prevention). Retrospective chart audit identified patient demographics, blood product exposure and Cytomegalovirus infection by polymerase chain reaction. A separate audit examined Cytomegalovirus seronegative blood product ordering in a broader range of hospital types.

RESULTS

We identified 122 and 66 Cytomegalovirus negative donor/recipient haemopoietic stem cell transplant pairs using double and single transfusion prevention strategy respectively. Transfusion exposure to red cells and pooled platelets was similar, though more apheresis platelets were used in the double prevention group. Cytomegalovirus infection rate was 3 (2.4%) and zero in the double and single prevention groups respectively. Cytomegalovirus seronegative unit ordering was not limited to hospitals with obstetric or neonatal populations, suggesting ongoing reliance of Cytomegalovirus seronegative units outside this population.

CONCLUSION

The analysis suggests a double prevention strategy does not provide additional protection against transfusion transmitted Cytomegalovirus. There is ongoing variability in the acceptance of leucocyte depletion alone despite the low risk of Cytomegalovirus infection This article is protected by copyright. All rights reserved.

Survey on Transfusion-Transmitted Cytomegalovirus and Cytomegalovirus Disease Mitigation

CONTEXT

- Cytomegalovirus (CMV) can be transmitted by cellular blood products, leading to severe disease in immunosuppressed patients such as neonates and transplant recipients. To mitigate transfusion-transmitted CMV (TT-CMV), "CMV-safe" blood products (leukoreduced and/or CMV-seronegative) are transfused. Attempts to develop practice guidelines for TT-CMV mitigation have been limited by paucity of high-quality clinical trials.

OBJECTIVE

- To assess current TT-CMV mitigation strategies across medical institutions for specific at-risk populations.

DESIGN

- Supplemental questions regarding TT-CMV and CMV disease mitigation were added to a College of American Pathologists Transfusion Medicine (Comprehensive) Participant Survey in 2015, addressing whether a given institution provided CMV-safe products for 6 at-risk patient populations.

RESULTS

- Ninety percent (2712 of 3032) of institutions reported providing universally leukoreduced blood products. Among institutions without universal leukoreduction, 92% (295 of 320) provided leukoreduced products on the basis of clinical criteria. Eighty-three percent (2481 of 3004) of respondents reported having availability of CMV-seronegative products; however, wide variation in policies was reported governing CMV-seronegative product use. Among all respondents, less than 5% reported using CMV prophylaxis and monitoring in high-risk patient groups. Transplant centers reported higher rates of CMV prophylaxis (25% [97 of 394] solid organ) and monitoring (15% [59 of 394] solid organ) for CMV-negative transplant recipients.

CONCLUSIONS

- Universal leukoreduction is the primary strategy for mitigating TT-CMV. While most institutions have both CMV-seronegative and leukoreduced blood products available, consensus is lacking on which patients should receive these products. High-quality studies are needed to determine if CMV-seronegative and leukoreduced blood products are needed in high-risk patient populations.

Impaired Hippocampal Glutamate and Glutamine Metabolism in the db/db Mouse Model of Type 2 Diabetes Mellitus

Type 2 diabetes mellitus (T2DM) is a risk factor for the development of Alzheimer's disease, and changes in brain energy metabolism have been suggested as a causative mechanism. The aim of this study was to investigate the cerebral metabolism of the important amino acids glutamate and glutamine in the db/db mouse model of T2DM. Glutamate and glutamine are both substrates for mitochondrial oxidation, and oxygen consumption was assessed in isolated brain mitochondria by Seahorse XFe96 analysis. In addition, acutely isolated cerebral cortical and hippocampal slices were incubated with [U-¹³C]glutamate and [U-¹³C]glutamine, and tissue extracts were analyzed by gas chromatography-mass spectrometry. The oxygen consumption rate using glutamate and glutamine as substrates was not different in isolated cerebral mitochondria of db/db mice compared to controls. Hippocampal slices of db/db mice exhibited significantly reduced ¹³C labeling in glutamate, glutamine, GABA, citrate, and aspartate from metabolism of [U-¹³C]glutamate. Additionally, reduced ¹³C labeling were observed in GABA, citrate, and aspartate from [U-¹³C]glutamine metabolism in hippocampal slices of db/db mice when compared to controls. None of these changes were observed in cerebral cortical slices. The results suggest specific hippocampal impairments in glutamate and glutamine metabolism, without affecting mitochondrial oxidation of these substrates, in the db/db mouse.