Extracellular DNA in blood products and its potential effects on transfusion

Association between perioperative plasma transfusion and in-hospital mortality in patients undergoing surgeries without massive transfusion: A nationwide retrospective cohort study

Background

An aggressive plasma transfusion is associated with a decreased mortality in traumatic patients requiring massive transfusion (MT). However, it is controversial whether non-traumatic or non-massively transfused patients can benefit from high doses of plasma.

Methods

We performed a nationwide retrospective cohort study using data from Hospital Quality Monitoring System, which collected anonymized inpatient medical records from 31 provinces in mainland China. We included the patients who had at least one record of surgical procedure and received red blood cell transfusion on the day of surgery from 2016 to 2018. We excluded those receiving MT or diagnosed with coagulopathy at admission. The exposure variable was the total volume of fresh frozen plasma (FFP) transfused, and the primary outcome was in-hospital mortality. The relationship between them was assessed using multivariable logistic regression model adjusting 15 potential confounders.

Results

A total of 69319 patients were included, and 808 died among them. A 100-ml increase in FFP transfusion volume was associated with a higher in-hospital mortality (odds ratio 1.05, 95% confidence interval 1.04-1.06, p < 0.001) after controlling for the confounders. FFP transfusion volume was also associated with superficial surgical site infection, nosocomial infection, prolonged length of hospital stay, ventilation time, and acute respiratory distress syndrome. The significant association between FFP transfusion volume and in-hospital mortality was extended to the subgroups of cardiac surgery, vascular surgery, and thoracic or abdominal surgery.

Conclusions

A higher volume of perioperative FFP transfusion was associated with an increased in-hospital mortality and inferior postoperative outcomes in surgical patients without MT.

Longitudinal profiling in patients undergoing cardiac surgery reveals postoperative changes in DNA methylation

BACKGROUND

Cardiac surgery and cardiopulmonary bypass induce a substantial immune and inflammatory response, the overactivation of which is associated with significant pulmonary, cardiovascular, and neurologic complications. Commensurate with the immune and inflammatory response are changes in the heart and vasculature itself, which together drive postoperative complications through mechanisms that are poorly understood. Longitudinal DNA methylation profiling has the potential to identify changes in gene regulatory mechanisms that are secondary to surgery and to identify molecular processes that predict and/or cause postoperative complications. In this study, we measure DNA methylation in preoperative and postoperative whole blood samples from 96 patients undergoing cardiac surgery on cardiopulmonary bypass.

RESULTS

While the vast majority of DNA methylation is unchanged by surgery after accounting for changes in cell-type composition, we identify several loci with statistically significant postoperative changes in methylation. Additionally, two of these loci are associated with new-onset postoperative atrial fibrillation, a significant complication after cardiac surgery. Paired statistical analysis, use of FACS data to support sufficient control of cell-type heterogeneity, and measurement of IL6 levels in a subset of patients add rigor to this analysis, allowing us to distinguish cell-type variability from actual changes in methylation.

CONCLUSIONS

This study identifies significant changes in DNA methylation that occur immediately after cardiac surgery and demonstrates that these acute alterations in DNA methylation have the granularity to identify processes associated with major postoperative complications. This research also establishes methods for controlling for cell-type variability in a large human cohort that may be useful to deploy in other longitudinal studies of epigenetic marks in the setting of acute and chronic disease.

Extruded small extracellular vesicles: splinters of circulating tumour cells may promote cancer metastasis?

We speculate ruptured circulating tumour cells (CTC) in capillaries could release a large number of small extracellular vesicle-like vesicles, namely mechanically extruded sEV (sEVme), which can encapsulate chromosomal DNA fragments. These sEVme have similar physicochemical properties compared to small extracellular vesicles spontaneously secreted by living cells (sEVss), and thus sEVme and sEVss cannot be effectively distinguished based on their size or membrane protein markers. Meanwhile, these sEVme derived from CTC inherit oncogenic payloads, deliver cargo through the bloodstream to recipient cells, and thus may promote cancer metastasis. The validation of this speculation could facilitate our understanding of EV biogenesis and cancer pathology. The potential finding will also provide a theoretical foundation for burgeoning liquid biopsy using DNA fragments derived from harvested sEV.

New Perspectives on the Importance of Cell-Free DNA Biology

Body fluids are constantly replenished with a population of genetically diverse cell-free DNA (cfDNA) fragments, representing a vast reservoir of information reflecting real-time changes in the host and metagenome. As many body fluids can be collected non-invasively in a one-off and serial fashion, this reservoir can be tapped to develop assays for the diagnosis, prognosis, and monitoring of wide-ranging pathologies, such as solid tumors, fetal genetic abnormalities, rejected organ transplants, infections, and potentially many others. The translation of cfDNA research into useful clinical tests is gaining momentum, with recent progress being driven by rapidly evolving preanalytical and analytical procedures, integrated bioinformatics, and machine learning algorithms. Yet, despite these spectacular advances, cfDNA remains a very challenging analyte due to its immense heterogeneity and fluctuation in vivo. It is increasingly recognized that high-fidelity reconstruction of the information stored in cfDNA, and in turn the development of tests that are fit for clinical roll-out, requires a much deeper understanding of both the physico-chemical features of cfDNA and the biological, physiological, lifestyle, and environmental factors that modulate it. This is a daunting task, but with significant upsides. In this review we showed how expanded knowledge on cfDNA biology and faithful reverse-engineering of cfDNA samples promises to (i) augment the sensitivity and specificity of existing cfDNA assays; (ii) expand the repertoire of disease-specific cfDNA markers, thereby leading to the development of increasingly powerful assays; (iii) reshape personal molecular medicine; and (iv) have an unprecedented impact on genetics research.

Comparison of Time Course Detection of Human Male DNA from Blood Stains on Various Objects on Surface in a Natural Environment and in a Laboratory Using Loop-Mediated Isothermal Amplification (LAMP)

In forensic study, the biological evidence can easily degrade, especially DNA. Degraded and environmentally challenged samples can produce numerous problems in forensic DNA analysis including loss of band product. Loop-mediated isothermal amplification or LAMP is one of the DNA analysis techniques used in forensic study. This study explores the limitations of the efficiency of the LAMP technique on abandoned DNA. For the DNA template, 8 male and 2 female blood-stained samples were taken from the surfaces, namely, brick, cloth, and tile from inside, and buried outside the laboratory. The LAMP reaction was used to amplify the SRY gene for detecting male DNA. All the blood-stained samples were stored for 1, 7, 15, 30, and 45 day (s). The LAMP product from the blood-stained samples on all the surfaces that were kept in a laboratory was detected using the gel electrophoresis technique from day 1 until day 45. However, the LAMP product on day 30 and 45 was smear and dim. The LAMP product from the blood-stained samples buried outside the laboratory was observed using the gel electrophoresis technique within day 30 (smear and dim). To increase the efficiency of detection, the qLAMP technique detected product on all the male samples from all the surfaces buried outside the laboratory for 45 days. The results indicate that this LAMP condition was possible detecting male DNA and the environmental factors are the main influence on the sensitivity of the LAMP technique. In addition, the qLAMP technique can increase the capacity and sensitivity of the detection.

Effects and Side Effects of Platelet Transfusion

Aside from their canonical role in hemostasis, it is increasingly recognized that platelets have inflammatory functions and can regulate both adaptive and innate immune responses. The main topic this review aims to cover is the proinflammatory effects and side effects of platelet transfusion. Platelets prepared for transfusion are subject to stress injury upon collection, preparation, and storage. With these types of stress, they undergo morphologic, metabolic, and functional modulations which are likely to induce platelet activation and the release of biological response modifiers (BRMs). As a consequence, platelet concentrates (PCs) accumulate BRMs during processing and storage, and these BRMs are ultimately transfused alongside platelets. It has been shown that BRMs present in PCs can induce immune responses and posttransfusion reactions in the transfusion recipient. Several recent reports within the transfusion literature have investigated the concept of platelets as immune cells. Nevertheless, current and future investigations will face the challenge of encompassing the immunological role of platelets in the scope of transfusion.

Aldehyde-Functionalized Magnetic Particles to Capture Off-Target Chemotherapeutic Agents

Drug capture is a promising technique to prevent off-target chemotherapeutic agents from reaching systemic circulation and causing severe side effects. The current work examines the viability of using immobilized aldehydes for drug-capture applications via Schiff base formation between doxorubicin (DOX) and aldehydes. Commercially available pyridoxal-5'-phosphate (VB6) was immobilized on iron oxide nanoparticles (IONPs) to capture DOX from human serum. Leaching of VB6 persisted as a primary issue and thus various aldehydes with anchoring groups such as catechol, silatrane, and phosphonate esters have been studied. The phosphonate group-based anchor was the most stable and used for further capture studies. To improve the hydrophilic nature of the aldehydes, sulfonate-containing aldehydes and polyethylene glycols (PEGs) were investigated. Finally, the optimized functionalized iron oxide particles, PEGylated-IONP, were used to demonstrate doxorubicin capture from human serum at biologically relevant temperature (37 °C), time (30 min), and concentrations (μM). The current study sets the stage for the development of potential compact dimension capture device based on surface-anchorable polymers with aldehyde groups.