Transfusion-Associated Microchimerism in Combat Casualties

Impacts of anemia and transfusion on oncologic outcomes in patients undergoing surgery for colorectal cancer

PURPOSE

This study aimed to evaluate the prevalence of preoperative anemia and impacts of anemia and transfusion on survival in patients undergoing surgery for colorectal cancer.

METHODS

This study included patients who underwent surgery for primary colorectal cancer between 2011 and 2012. The influence of preoperative anemia and postoperative transfusion on recurrence-free survival and overall survival were retrospectively investigated. Anemia was defined as hemoglobin level < 13 g/dL in males and < 12 g/dL in females. The primary outcome was the prevalence of preoperative anemia in patients with colorectal cancer. Secondary outcomes included preoperative anemia management, postoperative 30-day mortality and morbidity, tumor recurrence, and overall survival.

RESULTS

Among a total of 1899 patients, 823 patients (43.3%) were anemic preoperatively, and 264 patients (13.9%) received postoperative transfusions. Postoperative transfusion was associated with 30-day postoperative complications (OR = 1.514, 95% CI = 1.020 ~ 2.247) but not preoperative anemia (OR = 1.143, 95% CI, 0.811 ~ 1.611). Preoperative anemia (HR = 1.459, 95% CI = 1.104 ~ 1.929) and postoperative transfusion (HR = 1.566, 95% CI = 1.089 ~ 2.252) were significantly associated with worse recurrence-free survival in multivariable analysis. Preoperative anemia (HR = 1.572, 95% CI = 1.274 ~ 1.940) and postoperative transfusion (HR = 1.381, 95% CI = 1.076 ~ 1.773) were significant independent risk factors for worse overall survival.

CONCLUSIONS

Preoperative anemia and postoperative transfusion were associated with worse survival in patients undergoing surgery for colorectal cancer. An alternative therapy to treat anemia and reduce transfusions should be introduced to improve oncologic outcomes.

A Canadian Rural Living Lab Hospital: Implementing solutions for improving rural emergency care

INTRODUCTION

More than 6 million Canadians live in rural areas (approximately 20% of the population) and emergency services are a critical safety net for them.

OBJECTIVES

We want to create, in Baie-Saint-Paul (rural emergency department, Québec, Canada), an experimental milieu where all stakeholders develop, implement and evaluate solutions to address the problems that beset their environment.

METHOD

The Living Lab will rely on the quadruple aim approach to improve health system performance and will use a multimethod approach based on the philosophy of open and user-driven innovation. Three pilot projects will be implemented (quality of work life programme, computed tomography implementation study and telemedicine in ambulances). Other possible solutions will be evaluated and prioritised (in situ simulation, care protocol, telemedicine, point-of-care ultrasound, helicopters and drones).

CONCLUSION

We are confident that this Living Lab will contribute to saving lives, will improve the quality of work life for rural healthcare professionals, and will inspire similar innovation internationally.

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.

Profile of trauma mortality and trauma care resources at rural emergency departments and urban trauma centres in Quebec: a population-based, retrospective cohort study

OBJECTIVES

As Canada's second largest province, the geography of Quebec poses unique challenges for trauma management. Our primary objective was to compare mortality rates between trauma patients treated at rural emergency departments (EDs) and urban trauma centres in Quebec. As a secondary objective, we compared the availability of trauma care resources and services between these two settings.

DESIGN

Retrospective cohort study.

SETTING

26 rural EDs and 33 level 1 and 2 urban trauma centres in Quebec, Canada.

PARTICIPANTS

79 957 trauma cases collected from Quebec's trauma registry.

PRIMARY AND SECONDARY OUTCOME MEASURES

Our primary outcome measure was mortality (prehospital, ED, in-hospital). Secondary outcome measures were the availability of trauma-related services and staff specialties at rural and urban facilities. Multivariable generalised linear mixed models were used to determine the relationship between the primary facility and mortality.

RESULTS

Overall, 7215 (9.0%) trauma patients were treated in a rural ED and 72 742 (91.0%) received treatment at an urban centre. Mortality rates were higher in rural EDs compared with urban trauma centres (13.3% vs 7.9%, p<0.001). After controlling for available potential confounders, the odds of prehospital or ED mortality were over three times greater for patients treated in a rural ED (OR 3.44, 95% CI 1.88 to 6.28). Trauma care setting (rural vs urban) was not associated with in-hospital mortality. Nearly all of the specialised services evaluated were more present at urban trauma centres.

CONCLUSIONS

Trauma patients treated in rural EDs had a higher mortality rate and were more likely to die prehospital or in the ED compared with patients treated at an urban trauma centre. Our results were limited by a lack of accurate prehospital times in the trauma registry.

Trends and outcomes in multicomponent blood transfusion: an 11-year cohort study of a large multisite academic center

BACKGROUND

Most studies reporting on blood component utilization overlook patients transfused with more than one type of blood product (multicomponent transfusion). These patients are of importance, as they are large consumers of blood products and likely have different characteristics and outcomes than nontransfused patients and patients transfused with only one blood component type. Our study aimed to determine the prevalence of multicomponent transfusion at a large multisite academic center, as well as the patient characteristics and outcomes associated with multicomponent transfusion.

METHODS

A retrospective cohort study of transfused adult inpatients at the Ottawa Hospital between 2007 and 2017 was performed. Eligible transfusions were red blood cells (RBCs), platelets, plasma, cryoprecipitate, and/or fibrinogen concentrate. Descriptive analyses were done to determine multicomponent transfusion prevalence. Patient characteristics and outcomes associated with multicomponent transfusion were assessed using multivariable regressions.

RESULTS

Of 55,719 adult transfused inpatient admissions, 25% received a multicomponent transfusion. Multicomponent transfusion prevalence was highest in hematology (51%), cardiac surgery (45%), and critical care (40%) patients. Multivariable regression analysis showed that compared to RBC-only transfusion, multicomponent transfusion was associated with increased odds of in-hospital mortality (odds ratio, 3.48; 95% confidence interval [CI], 3.26-3.73), greater odds of institutional discharge as opposed to discharge home (odds ratio, 1.22; 95% CI, 1.15-1.30), and a 1.58 time increase in duration of hospitalization (95% CI, 1.54-1.62).

CONCLUSION

Multicomponent transfusion recipients make up a large proportion of transfused patients and have poorer outcomes. It is necessary to continue studying these patients, including outcomes and transfusion appropriateness, to inform best practices.

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.

Transfusion-associated microchimerism: the hybrid within

Microchimerism, the coexistence of genetically disparate populations of cells in a receptive host, is well described in both clinical and physiological settings, including transplantation and pregnancy. Microchimerism can also occur after allogeneic blood transfusion in traumatically injured patients, where donor cells have been observed decades after transfusion. To date, transfusion-associated microchimerism (TA-MC) appears confined to this clinical subset, most likely due to the immune perturbations that occur after severe trauma that allow foreign donor cells to survive. Transfusion-associated microchimerism appears to be unaffected by leukoreduction and has been documented after transfusion with an array of blood products. The only significant predictor of TA-MC to date is the age of red cells, with fresher units associated with higher risk. Thus far, no adverse clinical effect has been observed in limited studies of TA-MC. There are, however, hypothesized links to transfusion-associated graft vs host disease that may be unrecognized and consequently underreported. Microchimerism in other settings has gained increasing attention owing to a plausible link to autoimmune diseases, as well as its diagnostic and therapeutic potential vis-a-vis antenatal testing and adoptive immunotherapy, respectively. Furthermore, microchimerism provides a tool to further our understanding of immune tolerance and regulation.

The US military experience with fresh whole blood during the conflicts in Iraq and Afghanistan

Since its introduction in the early part of the last century, fresh whole blood (FWB) has been used by the US military as a battlefield expedient resuscitation method, even after the development of component therapy in the 1960s. In the recent conflicts in Iraq and Afghanistan, FWB was used once more, often collected in the setting of a walking blood bank (WBB). Considerable research and opinion from military circles has cited these experiences and sparked renewed interest in FWB as an effective resuscitation tool in the setting of trauma. Despite efforts by the US military to improve the effectiveness and safety of FWB through a series of widely published guidelines, transfusion transmitted infections (TTI) remain a vexing challenge. These experiences in Iraq and Afghanistan will help inform a larger discussion regarding the reintroduction of FWB in civilian trauma resuscitation.

Transfusion medicine in trauma patients

Injured patients stress the transfusion service with frequent demands for uncrossmatched red cells and plasma, occasional requirements for large amounts of blood products and the need for new and better blood products. Transfusion services stress trauma centers with demands for strict accountability for individual blood component units and adherence to indications in a clinical field where research has been difficult, and guidance opinion-based. New data suggest that the most severely injured patients arrive at the trauma center already coagulopathic and that these patients benefit from prompt, specific, corrective treatment. This research is clarifying trauma system requirements for new blood products and blood-product usage patterns, but the inability to obtain informed consent from severely injured patients remains an obstacle to further research.

Transfusion associated microchimerism: a heretofore little-recognized complication following transfusion

Potent antiplatelet and antithrombotic agents have significantly reduced mortality in the setting of acute coronary syndromes and percutaneous coronary intervention. However these agents are associated with increased bleeding which is in turn associated with adverse clinical outcomes. In many centers, transfusion is often used to correct for blood loss. Blood transfusion in the setting of acute coronary syndrome has been associated with adverse clinical outcomes including increased mortality. Transfusion associated microchimerism (TA-MC) is a newly recognized complication of blood transfusion. There is engraftment of the donor's hematopoietic stem cells in patients who then develop microchimerism. This article discusses the association of bleeding/blood transfusion with adverse outcomes and the potential role of TA-MC in clinical outcomes.