Effect of Donor Sex on Recipient Mortality in Transfusion

Year in Review 2023: Noteworthy Literature in Cardiac Anesthesiology

Notable clinical research published in 2023 related to cardiac anesthesia included studies focused on resuscitation and pharmacology, regional anesthesia, technological advances, and novel gene therapies. We reviewed 241 articles to identify 25 noteworthy studies that represent the most significant research related to cardiac anesthesia from the past year. Overall, improvements in clinical practice have enabled decreased morbidity and mortality with a renewed focus on mechanical circulatory support and transplantation.

Potential Predictors for Deterioration of Renal Function After Transfusion

BACKGROUND

Transfusion of packed red blood cells (pRBCs) is still associated with risks. This study aims to determine whether renal function deterioration in the context of individual transfusions in individual patients can be predicted using machine learning. Recipient and donor characteristics linked to increased risk are identified.

METHODS

This study was registered at ClinicalTrials.gov (NCT05466370) and was conducted after local ethics committee approval. We evaluated 3366 transfusion episodes from a university hospital between October 31, 2016, and August 31, 2020. Random forest models were tuned and trained via Python auto-sklearn package to predict acute kidney injury (AKI). The models included recipients' and donors' demographic parameters and laboratory values, donor questionnaire results, and the age of the pRBCs. Bootstrapping on the test dataset was used to calculate the means and standard deviations of various performance metrics.

RESULTS

AKI as defined by a modified Kidney Disease Improving Global Outcomes (KDIGO) criterion developed after 17.4% transfusion episodes (base rate). AKI could be predicted with an area under the curve of the receiver operating characteristic (AUC-ROC) of 0.73 ± 0.02. The negative (NPV) and positive (PPV) predictive values were 0.90 ± 0.02 and 0.32 ± 0.03, respectively. Feature importance and relative risk analyses revealed that donor features were far less important than recipient features for predicting posttransfusion AKI.

CONCLUSIONS

Surprisingly, only the recipients' characteristics played a decisive role in AKI prediction. Based on this result, we speculate that the selection of a specific pRBC may have less influence than recipient characteristics.

Blood Donor Sex and Outcomes in Transfused Infants

Red blood cell transfusion is common in neonatal intensive care. Multiple trials have evaluated different thresholds for when to administer red blood cell transfusion. In contrast, there has been less focus on studies of the characteristics of red blood cells transfused into neonates. In this review, the authors summarize the emerging literature on the potential impact of the sex of blood donors on outcomes in transfused neonates using a systematic search strategy. The authors review the uncertainty generated from studies with conflicting findings and discuss considerations regarding the impact of blood donor sex and other characteristics on neonatal outcomes.

Towards the crux of sex-dependent variability in red cell concentrates

Donor sex can alter the RBC 'storage lesion' progression, contributing to dissimilarities in blood product quality, and thus adverse post-transfusion reactions. The mechanisms underlying the reduced sensitivity of female RBCs to storage-induced stress are partially ascribed to the differential effects of testosterone, progesterone, and estrogen on hemolytic propensity. Contributing to this is the increased proportion of more robust, biologically 'young' subpopulations of RBCs in females. Herein, we discuss the impact of sex hormones on RBCs and the relevance of these biological subpopulations to provide further insight into sex-dependent blood product variability.

Neonatal Blood Banking Practices

There is little formal guidance to direct neonatal blood banking practices and, as a result, practices vary widely across institutions. In this vulnerable patient population with a high transfusion burden, considerations for blood product selection include freshness, extended-storage media, pathogen inactivation, and other modifications. The authors discuss the potential unintended adverse impacts in the neonatal recipient. Concerns such as immunodeficiency, donor exposures, cytomegalovirus transmission, volume overload, transfusion-associated hyperkalemia, and passive hemolysis from ABO incompatibility have driven modifications of blood components to improve safety.

Red Blood Cell Storage: From Genome to Exposome Towards Personalized Transfusion Medicine

Over the last decade, the introduction of omics technologies-especially high-throughput genomics and metabolomics-has contributed significantly to our understanding of the role of donor genetics and nongenetic determinants of red blood cell storage biology. Here we briefly review the main advances in these areas, to the extent these contributed to the appreciation of the impact of donor sex, age, ethnicity, but also processing strategies and donor environmental, dietary or other exposures - the so-called exposome-to the onset and severity of the storage lesion. We review recent advances on the role of genetically encoded polymorphisms on red cell storage biology, and relate these findings with parameters of storage quality and post-transfusion efficacy, such as hemolysis, post-transfusion intra- and extravascular hemolysis and hemoglobin increments. Finally, we suggest that the combination of these novel technologies have the potential to drive further developments towards personalized (or precision) transfusion medicine approaches.