Exercised blood plasma promotes hippocampal neurogenesis in the Alzheimer's disease rat brain

BACKGROUND

Exercise training promotes brain plasticity and is associated with protection against cognitive impairment and Alzheimer's disease (AD). These beneficial effects may be partly mediated by blood-borne factors. Here we used an in vitro model of AD to investigate effects of blood plasma from exercise-trained donors on neuronal viability, and an in vivo rat model of AD to test whether such plasma impacts cognitive function, amyloid pathology, and neurogenesis.

METHODS

Mouse hippocampal neuronal cells were exposed to AD-like stress using amyloid-β and treated with plasma collected from human male donors 3 h after a single bout of high-intensity exercise. For in vivo studies, blood was collected from exercise-trained young male Wistar rats (high-intensity intervals 5 days/week for 6 weeks). Transgenic AD rats (McGill-R-Thy1-APP) were injected 5 times/fortnight for 6 weeks at 2 months or 5 months of age with either (a) plasma from the exercise-trained rats, (b) plasma from sedentary rats, or (c) saline. Cognitive function, amyloid plaque pathology, and neurogenesis were assessed. The plasma used for the treatment was analyzed for 23 cytokines.

RESULTS

Plasma from exercised donors enhanced cell viability by 44.1% (p = 0.032) and reduced atrophy by 50.0% (p < 0.001) in amyloid-β-treated cells. In vivo exercised plasma treatment did not alter cognitive function or amyloid plaque pathology but did increase hippocampal neurogenesis by ∼3 fold, regardless of pathological stage, when compared to saline-treated rats. Concentrations of 7 cytokines were significantly reduced in exercised plasma compared to sedentary plasma.

CONCLUSION

Our proof-of-concept study demonstrates that plasma from exercise-trained donors can protect neuronal cells in culture and promote adult hippocampal neurogenesis in the AD rat brain. This effect may be partly due to reduced pro-inflammatory signaling molecules in exercised plasma.

Effect of plasma transfusion on in-hospital mortality and morbidities in patients with spontaneous subarachnoid hemorrhage

OBJECTIVE

Spontaneous subarachnoid hemorrhage (SAH) is a critical condition in which patients may require plasma transfusion during hospitalization. However, it remains unknown whether plasma administration has detrimental effects on the prognosis of SAH beyond the correction of coagulopathy or hypovolemia. This study aimed to analyze the association of plasma transfusion with in-hospital mortality and morbidities in patients with SAH.

METHODS

We retrospectively analyzed the data of 1689 adult patients with a primary diagnosis of spontaneous SAH. Differences in the clinical parameters were evaluated between patients who received plasma transfusion and those who did not.

RESULTS

Of 1689 patients, 158 (9.4%) received plasma transfusion. Statistical analysis revealed significant differences in pre-existing comorbidity prevalence between the two study groups. The post-SAH morbidities, including cerebral ischemic events (13.3% vs. 6.4%; p = 0.01), were more common in the plasma transfusion group, whereas the mortality rate was not different between the two study groups (p = 0.166). The mean duration of hospital stay was 19.3 ± 14.4 days and 15.1 ± 15.2 days for patients with and without plasma transfusion, respectively (p = 0.001).

CONCLUSION

Plasma transfusion following spontaneous SAH is not uncommon. Although the in-hospital mortality rate does not increase following plasma transfusion, cerebral ischemic events as well as other morbidities are more frequent in patients receiving plasma transfusion. Therefore, the indication for plasma transfusion following SAH needs careful weighing and should be further defined by well-controlled studies.

Plasma transfusion in critically Ill patients with abnormal coagulation tests before invasive procedures: A propensity-adjusted cohort study

OBJECTIVE

To evaluate the association between plasma transfusion and bleeding complications in critically ill patients with an elevated international normalized ratios undergoing invasive procedures.

METHODS

A retrospective study was conducted to evaluate a consecutive sample of critically ill adult patients undergoing invasive procedures (N = 487) with an international normalized ratio ≥ 1.5 between January 1, 2019 and December 31, 2019. Among the followed patients, 125 were excluded due to incomplete case records and 362 were finally included in this investigation. The exposure was whether plasma had been transfused within 24 h before the invasive procedure. The primary outcome was the occurrence of postprocedural bleeding complications. Secondary outcomes included transfusion of red blood cells within 24 h of the invasive procedure, and additional patient-important outcomes such as mortality and length of stay. Tests were performed with univariate and propensity-matched analyses.

RESULTS

Of the 362 study participants, 99 (27.3 %) received a preprocedural plasma transfusion. In the propensity score-matched analysis, the rate of the occurrence of postprocedural bleeding complications between two groups was not statistically different (OR, 0.605[95 % CI, 0.341-1.071]; P = .085). The rate of postoperative red blood cell transfusion in the plasma transfusion group was higher than that in the non-plasma transfusion group (35.5 % vs 21.5 %; P < .05). No statistically significant difference in mortality was observed between the two groups (29.0 % vs 31.6 %; P = .101).

CONCLUSIONS

Prophylactic plasma transfusion failed to reduce postprocedural bleeding complications in ill critically patients with a coagulopathy. Meanwhile, it was associated with increased red blood cell transfusion after invasive procedures. Findings suggest that abnormal preprocedural international normalized ratios should be managed more conservatively.

Trajectory of SARS-CoV-2 anti-S IgG levels following transfusion and a third dose of BNT162b2 vaccine in a patient with massive postoperative bleeding: A case report

Objective

Vaccination against SARS-CoV-2 has been shown to be effective in preventing infection and severe disease. Massive bleeding and transfusion after vaccination can lead to a decrease in the antibody level. The effect of an additional dose of vaccine after blood transfusion has not been described previously. In this case report, we report the SARS-CoV-2 anti-S IgG trajectory in a male patient who received a third dose of vaccine after a massive postoperative bleed and blood and plasma transfusion.

Case presentation

A 57-year-old male physician had a SARS-CoV-2 anti-S IgG level of 44 AU/mL, measured using the Lumipulse Presto chemiluminescence assay 3 months after receiving 2 doses of the BNT162b2 vaccine. The patient underwent a hemicolectomy for colon cancer, experienced massive postoperative bleeding, and required a transfusion. The patient's SARS-CoV-2 anti-S IgG level dropped to 9.2 AU/mL. A third dose of BNT162b2 vaccination was administered to reduce the risk of breakthrough infection. Fifteen days after receiving the third vaccine dose, the patient's SARS-CoV-2 anti-S IgG level increased to 421 AU/mL, likely to reflect protection.

Conclusion

This report suggests that administering an extra dose of vaccine is useful for restoring protective antibody levels in vaccinated patients who experience massive postoperative bleeding.

Invasive Procedures in Patients with Cirrhosis: A Clinical Approach Based on Current Evidence

The aim on of this article is to provide an update on the coagulation disturbances of patients with cirrhosis. It summarizes basic concepts of coagulation in cirrhosis, available tests used to predict bleeding, procedures and risk of bleeding, and the rationale and expert-based recommendations of prophylactic measures for patients with cirrhosis who undergo invasive procedures.

Institution of prothrombin complex concentrate protocols is associated with a reduction in plasma administration at a Tertiary Care Hospital

STUDY OBJECTIVE

Explore how the introduction of 4-factor prothrombin complex concentrates (4F-PCC) protocols for reversing anticoagulation and the treatment of critical bleeding influenced blood product utilization.

DESIGN

A retrospective analysis of the utilization rate of plasma and 4F-PCC from September 2012 through December 2018.

SETTING

Blood bank and pharmacy records of a single large tertiary care medical center.

PATIENTS

Admitted patients except obstetric during the study period (n = 283,319).

INTERVENTION

Five institutional protocols providing guidelines for 4F-PCC administration were deployed over a 3-year period.

MEASUREMENTS

The utilization rate of plasma and 4F-PCC was the primary outcome and analyzed using an interrupted time series analysis. Utilization of platelets and cryoprecipitate as well as the impact of the intervention on the service prescribing the blood products were evaluated as secondary outcomes. Data were evaluated using a segmented time series regression.

RESULTS

When adjusted for seasonality, the monthly rate of plasma administration was 24.7 ± 2.0 units per 100 admissions in the 6-month period prior to the 1st intervention (May-October 2013) and decreased to 9.9 ± 2.2 units per 100 admissions in the same six-month period following the 5th intervention (May-October 2018), median difference - 14.5, 95% CI -16.0 to -13.2, P < 0.001. During the 6-month period prior to the 1st intervention (May-October 2013) the monthly rate of 4-F PCC use was 1.2 ± 0.8 doses per 1000 admissions and increased to 2.8 ± 1.0 doses per 1000 admissions 6-months following the 5th intervention (May-October 2018), median difference 1.6, 95% CI 0.3 to 1.9, P = 0.014. The monthly utilization of platelets was decreased and cryoprecipitate slightly increased following the implementation of the PCC protocols.

CONCLUSIONS AND RELEVANCE

Our findings demonstrate that establishing institutional protocols for the use of 4F-PCC to reverse the effects of anticoagulation and to treat critical bleeding with associated coagulopathy was associated with reduced plasma utilization.

Plasma Transfusion Practice in Adult Surgical Patients: Systematic Review of the Literature

Background

Plasma transfusions are most commonly used therapeutically for bleeding or prophylactically in non-bleeding patients prior to invasive procedures or surgery. Although plasma transfusions generally seem to decline, plasma usage for indications that lack evidence of efficacy prevail.

Summary

There is wide international, interinstitutional, and interindividual variance regarding the compliance with guidelines based on published references, supported by appropriate testing. There is furthermore a profound lack of evidence from randomized controlled trials comparing the effect of plasma transfusion with that of other therapeutic interventions for most indications, including massive bleeding. The expected benefit of a plasma transfusion needs to be balanced carefully against the associated risk of adverse events. In light of the heterogeneous nature of bleeding conditions and their rapid evolvement over time, fibrinogen and factor concentrate therapy, directed at specific phases of coagulation identified by alternative laboratory assays, may offer advantages over conventional blood product ratio-driven resuscitation. However, their outcome benefit has not been demonstrated in well-powered prospective trials. This systematic review will detail the current evidence base for plasma transfusion in adult surgical patients.

An overview on COVID-19: reality and expectation

Recently, severe acute respiratory syndrome coronavirus 2 (SARS-COV-2), commonly known as coronavirus disease-2019 (COVID-19) has rapidly spread across China and around the world. By the declaration of WHO, COVID-19 outbreak considered as a public health problem of international concern. The aim of this study is to provide a comprehensive view on COVID-19 and the future expectations to control virus progression. Patients with liver disease, diabetes, high blood pressure, and obesity are more susceptible to the incidence of COVID-19 infection. So, there is a rapid need for disease diagnosis, vaccine development, and drug discovery to detect, prevent, and treat this sudden and lethal virus. Real-time polymerase chain reaction (RT-PCR) is considered as a rapid, accurate, and specific tool for disease diagnosis. Under this emergency situation that the world facing against COVID-19, there are about 15 potential vaccine candidates tested globally based on messenger RNA, DNA-based, nanoparticle, synthetic, and modified virus-like particle. Certain drugs that are clinically approved for other diseases were tested against COVID-19 as chloroquine, hydroxychloroquine, ivermectin, favipiravir, ribavirin, and remdesivir. Convalescent plasma transfusion and traditional herbal medicine were also taken into consideration. Due to the absence of effective treatment or vaccines against COVID-19 so far, the precautionary measures according to WHO's strategic objectives are the only way to confront this crisis. Governments should adopt national medical care programs to reduce the risk of exposure to any future viral outbreaks especially to patients with pre-existing medical conditions.

Recent advances in use of fresh frozen plasma, cryoprecipitate, immunoglobulins, and clotting factors for transfusion support in patients with hematologic disease

Hematologic diseases include a broad range of acquired and congenital disorders, many of which affect plasma proteins that control hemostasis and immune responses. Therapeutic interventions for these disorders include transfusion of plasma, cryoprecipitate, immunoglobulins, or convalescent plasma-containing therapeutic antibodies from patients recovering from infectious diseases, as well as concentrated pro- or anticoagulant factors. This review will focus on recent advances in the uses of plasma and its derivatives for patients with acquired and congenital hematologic disorders.

Transfusion With 2 L of Hyperimmune Plasma is Superior to Transfusion of 1 L or Less for Protecting Foals Against Subclinical Pneumonia Attributed to Rhodococcus equi

Transfusing foals with Rhodococcus equi hyperimmune plasma (REHIP) is a standard practice at many horse-breeding farms to help prevent R. equi pneumonia. At many large breeding farms, pneumonia is most commonly recognized as subclinical based on thoracic ultrasonography findings. The efficacy of REHIP transfusion and the impact of the volume of plasma transfused for reducing the cumulative incidence of subclinical R. equi pneumonia are unknown. A retrospective cohort study was conducted among foals born and residing through weaning at a large breeding farm. Foals were transfused with either 0 L (n = 2 foals), 1 L (n = 85 foals), or 2 L (n = 62 foals) of REHIP within 36 hours of birth. Volume transfused was principally based on intended use of the foals. All foals at the ranch were routinely screened using thoracic ultrasonography at 5, 7, and 9 weeks of age to detect subclinical pneumonia attributed to R. equi based on farm history. The proportion of the foals receiving < 1 L REHIP that developed subclinical pneumonia (32%; 26/82) was significantly (P = .0068; chi-squared test) greater than that among foals transfused with 2 L of REHIP (12%; 8/68). Despite the important limitations of this observational study, it provides evidence supporting the need for well-designed clinical trials to evaluate the impact of the use and dose of REHIP for preventing subclinical pneumonia. Reducing the incidence of subclinical pneumonia is important because reducing antibiotic treatment of subclinical cases will decrease selection pressure for antimicrobial resistance in R. equi.

Extending the pre-processing holding time of whole blood beyond 48 h reduces coagulation FVIII activity and immunoglobulin G content of recovered plasma

BACKGROUND

Plasma obtained via whole blood (WB) donation may be used either for transfusion or as recovered plasma (RP) for pooling and fractionation. In Canada, transfusable plasma must be processed within 24 h of phlebotomy, while the limit for RP processing is 72 h. We assessed the quality of RP produced by two WB processing methods and as a function of processing time.

STUDY DESIGN AND METHODS

RP units produced via the buffy coat method (BCM, n = 26) or whole blood filtration (WBF, n = 52) were tested for: the activities of prothrombin, fibrinogen, von Willebrand Factor (VWF), FV, FVII, and FVIII; the prothrombin time (PT); and total protein and IgG concentration. WBF RP units were evenly divided between those processed <48 h of phlebotomy (shorter-processed) or 48-72 h after phlebotomy (longer-processed).

RESULTS

WBF-RP did not differ significantly from BCM-RP in any tested parameter except for FV and FVIII, which exhibited mean reductions of 10.2% and 20%, respectively. Longer-processed WBF-RP did not differ significantly from shorter-processed WBF-RP in any tested parameter except for FVIII activity and IgG concentration, which exhibited mean reductions of 30.1% and 14.3%, respectively.

CONCLUSIONS

Canadian RP is currently fractionated into IgG, albumin, fibrinogen, and FVII/VWF concentrates irrespective of its method or time of processing. Our results supported the current approach of fractionating both BCM- and WBF-derived RP, but suggest that greater yields of immunoglobulin and FVIII/VWF products could be obtained if the maximum processing time was reduced from 72 h to 48 h.

Identification of Clinically Meaningful Plasma Transfusion Subgroups Using Unsupervised Random Forest Clustering

Statistical techniques such as propensity score matching and instrumental variable are commonly employed to "simulate" randomization and adjust for measured confounders in comparative effectiveness research. Despite such adjustments, the results of these methods apply essentially to an "average" patient. However, as patients show significant heterogeneity in their responses to treatments, this average effect is of limited value. It does not account for individual level variabilities, which can deviate substantially from the population average. To address this critical problem, we present a framework that allows the discovery of clinically meaningful homogeneous subgroups with differential effects of plasma transfusion using unsupervised random forest clustering. Subgroup analysis using two blood transfusion datasets show that considerable variablilities exist between the subgroups and population in both the treatment effect of plasma transfusion on bleeding and mortality and risk factors for these outcomes. These results support the customization of blood transfusion therapy for the individual patient.

14-Day thawed plasma retains clot enhancing properties and inhibits tPA-induced fibrinolysis

BACKGROUND

Plasma-first resuscitation attenuates trauma-induced coagulopathy (TIC); however, the logistics of plasma-first resuscitation require thawed plasma (TP) be readily available due to the obligatory thawing time of fresh frozen plasma (FFP). The current standard is storage of TP for up to 5 days at 4°C, based on factor levels at outdate, for use in patients at risk for TIC, but there remains a 2.2% outdated wastage rate. However, the multitude of plasma proteins in attenuating TIC remains unknown. We hypothesize that TP retains the ability to enhance clotting and reduce tPA-induced fibrinolysis at 14-day storage.

METHODS

FFP was thawed and stored at 4°C at the following intervals: 14, 10, 7, 5, 3, and 1-day prior to the experiment. Healthy volunteers underwent blood draws followed by 50% dilution with TP stored at previously mentioned intervals as well as FFP, normal saline (NS), albumin, and whole blood (WB) control. Samples underwent tPA-modified (75 ng/mL) thrombelastography (TEG) with analysis of R-time, angle, maximum amplitude (MA), and LY30.

RESULTS

TEG properties did not change significantly over the thawed storage. 14-day TP retained the ability to inhibit tPA-induced hyperfibrinolysis (median LY30% 9.6%) similar to FFP (5.6%), WB (14.6%), and superior to albumin (59.3%) and NS (58.1%). 14-day TP also retained faster clot formation (median angle, 66.2°) and superior clot strength (MA, 61.5 mm) to albumin (34.8°, 21.6 mm) and NS (41.6°, 32.2 mm).

CONCLUSIONS

TP plasma stored for 14 days retains clot-enhancing ability and resistance to clot degradation similar to FFP. A clinical trial is needed to validate these in vitro results.

Plasma Transfusion in Patients With Cirrhosis in China: A Retrospective Multicenter Cohort Study

Patients with cirrhosis used to be associated with frequent use of blood components because of their complex disorder of hemostasis and bleeding complications. Recent findings have indicated that patients with cirrhosis have a state of "rebalanced" or even procoagulant hemostasis and have questioned the prophylactic use of plasma. To evaluate the current status of plasma use in patients with cirrhosis, we conducted a retrospective survey in 11 tertiary-care hospitals in China from September 1 to October 31, 2013. All patients admitted with cirrhosis during the study period were included in the study. The survey collected information including patients' diagnostic and demographic data, clinical course including bleeding complications and invasive procedures, laboratory results, and plasma transfusion data. Among 1595 patients with cirrhosis admitted to the 11 hospitals, 236 (14.8%) patients received 1 or more plasma transfusions during the study period. The number of plasma transfusions is defined as the number of transfusion orders. A total of 1037 plasma transfusions were administered to these patients, with a mean of 4.4 transfusions per transfused patient, ranging from 1 to 22 transfusions per transfused patient. Most plasma transfusions (760/1037; 73.3%) were given to patients without bleeding, for treatment of coagulopathy either without planned invasive procedures (70.4%) or before invasive procedures (2.9%). The median dose of plasma transfusion was 3.8 mL/kg. The rate of plasma transfusion of participating hospitals varied from 5.3% to 31.8%. It is encouraging to see that in one teaching hospital, 85.7% plasma transfusions were given to patients with bleeding indication, showing a promising sign in appropriate transfusion. Prophylaxis or empirical plasma transfusion is still a common problem in managing patients with liver cirrhosis. Wide variations are found in plasma transfusion practice among hospitals. Effective measures to control and reduce empirical correction of abnormal coagulation tests through transfusing plasma should be strengthened urgently.

Performance of the PEdiatric Logistic Organ Dysfunction-2 score in critically ill children requiring plasma transfusions

BACKGROUND

Organ dysfunction scores, based on physiological parameters, have been created to describe organ failure. In a general pediatric intensive care unit (PICU) population, the PEdiatric Logistic Organ Dysfunction-2 score (PELOD-2) score had both a good discrimination and calibration, allowing to describe the clinical outcome of critically ill children throughout their stay. This score is increasingly used in clinical trials in specific subpopulation. Our objective was to assess the performance of the PELOD-2 score in a subpopulation of critically ill children requiring plasma transfusions.

METHODS

This was an ancillary study of a prospective observational study on plasma transfusions over a 6-week period, in 101 PICUs in 21 countries. All critically ill children who received at least one plasma transfusion during the observation period were included. PELOD-2 scores were measured on days 1, 2, 5, 8, and 12 after plasma transfusion. Performance of the score was assessed by the determination of the discrimination (area under the ROC curve: AUC) and the calibration (Hosmer-Lemeshow test).

RESULTS

Four hundred and forty-three patients were enrolled in the study (median age and weight: 1 year and 9.1 kg, respectively). Observed mortality rate was 26.9 % (119/443). For PELOD-2 on day 1, the AUC was 0.76 (95 % CI 0.71-0.81) and the Hosmer-Lemeshow test was p = 0.76. The serial evaluation of the changes in the daily PELOD-2 scores from day 1 demonstrated a significant association with death, adjusted for the PELOD-2 score on day 1.

CONCLUSIONS

In a subpopulation of critically ill children requiring plasma transfusion, the PELOD-2 score has a lower but acceptable discrimination than in an entire population. This score should therefore be used cautiously in this specific subpopulation.

Plasma is ineffective in correcting mildly elevated PT-INR in critically ill children: a retrospective observational study

Background

Fresh frozen plasma transfusion is widely utilized in pediatric clinical practice to correct mild coagulopathy. Several studies on adult population have shown that transfusion of plasma cannot effectively correct mild coagulopathy when international normalized ratio (INR) is ≤1.5. Much controversy exists about the generalization of this finding for pediatric populations, especially since pediatric dosages often exceed those in adults. The aim of this study is to determine the prevalence of plasma transfusion with mild coagulopathy (INR ≤ 1.5) and its effectiveness in a pediatric setting.

Methods

In our tertiary referral hospital, we retrospectively reviewed the electronic medical records of all patients who received plasma (April to October 2011) for mildly elevated prothrombin time (PT)-INR levels (≤1.5) and had post-transfusion PT-INR measurements; patients who received intraoperative, ECMO, or plasma exchange-related plasma transfusions were excluded from this study. We abstracted demographic data and pre- and post coagulation test results for the patients included in our study.

Results

Among 468 plasma transfusions administered to 285 patients from April to June 2011, 60 plasma transfusions (12.8%) were given to patients with PT-INR ≤ 1.5 (range 1.3–1.5). Forty-one patients [median age 2.5 years (IQR, 0.14 to 13.75 years), median weight of 16.0 kg (IQR, 8.0 to 69.3 kg)] who received 41 single plasma transfusions [median dose 11 mL/Kg (IQR, 6–15)] had post-transfusion PT-INR measurements and were included in our study. There was no significant difference in their PT-INR values (p = 0.34) pre- and post-transfusion. Of our study, only 15.4% patients showed post-transfusion normalization [median change in PT-INR 0.15 (IQR, 0.1–0.2)] and were not different from the remaining 85% in age, plasma dose, and bleeding status.

Conclusions

The prevalence of plasma transfusion for correction of mildly elevated PT-INR levels in critically ill children is high (12.8%). Plasma transfusion showed no significant effect in correcting minor prolongation of PT-INR in pediatric patients regardless of age, volume of plasma transfused per kilogram (dosage), or bleeding status.