Right Ventricular Maladaptation to Pressure Overload in Fischer Rats Is Associated With Profound Deficiency in Adenylate Kinase 1 and Impaired Ventricular Energetics.

BACKGROUND: We explored the mechanism of maladaptive right ventricular (RV) remodeling in Fischer compared with Sprague-Dawley (SD) rats exposed to pressure overload. METHODS: Pulmonary hypertension was induced by injection of the VEGFR antagonist, SU5416, followed by a 3-week exposure to hypoxia (Sugen chronic hypoxia). In vivo oxidative metabolism was assessed by RV/left ventricle ratio of [11C]acetate positron emission tomography clearance (kmono). Unbiased, global transcriptional and proteomic profiling was performed in Fischer and SD rats at baseline and after Sugen chronic hypoxia. RESULTS: All Fischer rats succumbed to RV failure by 5 weeks, whereas SD rats showed preserved RV function and 88% survival beyond 9 weeks (P<0.0001). Fischer rats exhibited increased oxidative metabolism at 4 weeks (P<0.05) and impaired RV efficiency compared with SD (work metabolic index: 52±10 versus 91±27 mmHg·mL/cm2, respectively; P<0.05), but no differences in mitochondrial complex activity. AK1 (adenylate kinase 1) was among the top 10 differentially expressed genes between Fischer and SD rats, with markedly lower RV expression in Fischer rats (FC: 3.36, P<0.05), confirmed by proteomic analysis and validated by Western blotting (>10-fold reduction, P<0.001). While whole-genome sequencing failed to reveal any coding region mutations in Fischer rats, there was a unique variant in a highly conserved upstream flanking region likely involved in the regulation of AK1 expression. CONCLUSIONS: Therefore, Fischer rats exhibit profound AK1 deficiency and inefficient cardiac energetics likely related to reduced adenosine triphosphate shuttling from the mitochondria to the contractile fibers. This represents a novel mechanism for RV failure in response to chronic increases in afterload.

A Randomized Double-Blind Placebo-Control Feasibility Trial of Immunoglobulin Treatment for Prevention of Recurrent Acute Exacerbations of COPD.

BACKGROUND: Observational studies suggest that immunoglobulin treatment may reduce the frequency of acute exacerbations of COPD (AECOPD). OBJECTIVE: To inform the design of a future randomised control trial (RCT) of intravenous immunoglobulin (IVIG) treatment efficacy for AECOPD prevention. METHODS: A pilot RCT was conducted. We recruited patients with COPD hospitalized for AECOPD, or from ambulatory clinics with one severe, or two moderate AECOPD in the previous year regardless of their serum IgG level. Patients were allocated in a 1:1 ratio with balanced randomisation to monthly IVIG or normal saline for 1 year. The primary outcome was feasibility defined as pre-specified accrual, adherence, and follow-up rates. Secondary outcomes included safety, tolerance, AECOPD rates, time to first AECOPD, quality of life, and healthcare costs. RESULTS: Seventy patients were randomized (37 female; mean age 67.7; mean FEV1 35.1%). Recruitment averaged 4.5±0.9 patients per month (range 0-8), 34 (49%) adhered to at least 80% of planned treatments, and four (5.7%) were lost to follow-up. There were 35 serious adverse events including seven deaths and one thromboembolism. None was related to IVIG. There were 56 and 48 moderate and severe AECOPD in the IVIG vs control groups. In patients with at least 80% treatment adherence, median time to first moderate or severe AECOPD was 275 vs 114 days, favoring the IVIG group (HR 0.76, 95% CI 0.3-1.92). CONCLUSION: The study met feasibility criteria for recruitment and retention, but adherence was low. A trend toward more robust treatment efficacy in adherent patients supports further study, but future trials must address treatment adherence. TRIAL REGISTRATION NUMBER: NCT0290038, registered 24 February 2016, https://clinicaltrials.gov/ct2/show/NCT02690038 and NCT03018652, registered January 12, 2017, https://clinicaltrials.gov/ct2/show/NCT03018652.

Exploring Peaks in Hospital Blood Component Utilization: A 10-Year Retrospective Study at a Large Multisite Academic Centre.

Peak demand analysis is common in industries such as the energy sector, but can also be applied to the field of transfusion to characterize the nature and timing of peak days in hospital blood utilization. This information can be used to forecast future peak days or to inform hospital emergency preparedness plans. The aims of this study are to characterize peak days in red blood cell (RBC) utilization over the past 10 years at our hospital, and to compare RBC peaks with peaks in platelet, plasma, and cryoprecipitate utilization. This was a retrospective cohort study of RBC, platelet, plasma, and cryoprecipitate transfusions in the inpatient and emergency department setting between May 2009 and April 2019 at a large academic hospital, containing regional trauma and cardiovascular surgery centers. For each blood product, a peak in utilization was defined as a day with a ≥50% increase in the number of units transfused compared to the previous 90-day average. Descriptive and inferential analyses were performed to characterize peak days. There were on average 20,501 RBCs transfused per year and 56 RBCs transfused per day over the 10-year period. A total of 134 peaks in RBC utilization occurred over the study period, with an average of 14 peaks per year. RBC peak days required on average 69% more RBC units compared to nonpeak days (P< .0001). 77% of RBC peaks were caused either solely or in part by surgical bleeding, 34% were caused entirely or in part by trauma, and other causes were infrequent. RBC peaks occurred most often on Fridays and least often on weekends (P< .0001). While there were 134 RBC peaks over the study period, there was a larger number of platelet (n = 292), plasma (n = 467), and cryoprecipitate peaks (n = 579). RBC peak days often coincided with plasma peak days, but less frequently with platelet and cryoprecipitate peaks. More studies are needed to determine whether analysis of peak usage will be of value to hospital blood banks for emergency planning and blood inventory management.

Healthcare resource utilization and costs among patients with direct oral anticoagulant or warfarin-related major bleeding.

INTRODUCTION: Direct oral anticoagulants (DOACs) have expanded the options for antithrombotic therapy. DOAC-related major bleeds are associated with favorable outcomes compared to warfarin in clinical trials and routine practice. However, it is unclear whether management of DOAC-associated major bleeding incurs higher resource utilization and costs. MATERIALS AND METHODS: We screened medical records of patients ≥ 66 years with atrial fibrillation admitted to one of five tertiary care hospitals in Ontario, Canada with a hemorrhage. We abstracted bleeds involving DOACs or warfarin and linked them to administrative databases to capture length of hospital stay, blood product use, procedural interventions, intensive care unit (ICU) utilization and related direct medical costs. To control for confounders, multivariate logistic and linear regressions were used for binary and linear outcomes respectively. RESULTS: Among 19,061 records screened, 1978 (10.4%) cases involving 1632 patients met criteria of oral anticoagulant-associated bleeding. Baseline characteristics between DOAC and warfarin groups were similar. Blood product costs were higher for DOACs (all comparisons DOACs vs. warfarin, $1456 vs. $1109, mean difference $347, 95% CI $185 to $509), but length of stay and ICU use were similar. Mean direct medical costs did not differ ($9217 vs. $10,790, adjusted relative ratio 0.94, 95% CI 0.84-1.05). CONCLUSIONS: Prior to introduction of DOAC-specific reversal agents, resource utilization and medical costs were comparable between DOAC- and warfarin-associated major bleeds, despite marginally higher blood product costs incurred by the former. Resource intensity associated with anticoagulant-related bleeding remains high, and our data provide measures for cost-effectiveness evaluation of emerging DOAC antidotes.

Study protocol: a randomized, double-blind, parallel, two-arm, placebo control trial investigating the feasibility and safety of immunoglobulin treatment in COPD patients for prevention of frequent recurrent exacerbations.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a chronic progressive inflammatory disease of the airways, associated with frailty, disability, co-morbidity, and mortality. Individuals with COPD experience increased risk and rates of acute exacerbation as their lung disease worsens. Current treatments to prevent acute exacerbation of COPD (AECOPD) are only modestly effective. New therapies are needed to improve the quality of life and clinical outcomes for individuals living with COPD and especially for those prone to frequent recurrent AECOPD. Recent research has suggested an association of gammaglobulin or immunoglobulin G levels with AECOPD and a favorable effect of an immunoglobulin treatment on the frequency of recurrent AECOPD, healthcare provider visits, treatments, and hospitalizations. However, control trials are required to confirm this apparent association and therapeutic effect. This study aims to assess if intravenous immunoglobulin (IVIG) therapy is feasible, safe, tolerable, and potentially effective in reducing the frequency of recurrent AECOPD. METHODS/DESIGN: Adult COPD patients at The Ottawa Hospital (TOH) will be recruited to partake in a randomized double-blind, parallel, two-arm, placebo control trial. Eligible patients will be administered either IVIG or normal saline following 1:1 randomization and every 4 weeks for 1 year. The primary outcome of feasibility will be determined by recruitment, patient adherence, safety and tolerance, success of the follow-up procedures, and outcome measurement. The safety and tolerability will be assessed through adverse events, adherence, and study withdrawals. Efficacy trends will be investigated by assessing incidence rates of AECOPD, improvement in quality of life, and healthcare services use and cost. DISCUSSION: The study results will inform larger studies designed to confirm a clinically significant therapeutic effect in identifiable populations which would be a major advance in the care of COPD patients. TRIAL REGISTRATION NUMBER: ClinicalTrial.gov, NCT03018652 and NCT02690038.

"HERDOO2" clinical decision rule to guide duration of anticoagulation in women with unprovoked venous thromboembolism. Can I use any d-Dimer?

BACKGROUND: The "HERDOO2 rule" is a prospectively validated clinical decision rule used to identify low-risk women who can safely discontinue anticoagulants after completing 5-12 months of anticoagulant treatment for unprovoked venous thromboembolism. The VIDAS®d-Dimer (DD) assay, a component of the rule, was used in the derivation and validation of the rule at half the usual diagnostic cut-point for exclusion of venous thrombosis. It is unknown if other commercial DD assays used at a corresponding cut-point will categorize patients at high concordance with the VIDAS® DD. OBJECTIVE: To determine if other available automated quantitative DD assays have high enough concordance with the VIDAS® DD assay to allow their use within the "HERDOO2" clinical decision rule. METHODS: Frozen plasma samples from a sub-set (n = 248) of female participants in the "HERDOO2" validation study were tested using five DD assays: VIDAS®, Innovance®, HemosIL®, Tina-quant® and Liatest®, with duplicate testing for 50 samples. First, using the mean DD for 50 samples with duplicate results, we determined the optimal cut-point values for each test that corresponded with a VIDAS® DD result of 250 µg/L using linear regression analysis. Next, kappa analysis was conducted on the DD results of the remaining 198 samples to determine concordance between each tested DD at the respective optimal cut-point and the VIDAS® DD at 250 µg/L. In a separate analysis we determined the concordance at half the usual venous thrombosis exclusion cut-point. RESULTS: Regression analysis of the DD results in 50 samples identified the optimal cut-point for each DD assay to match a VIDAS® DD cut-point of 250 µg/L: Innovance® 177 µg/L, Liatest® 233 µg/L, Tina-quant® 48 µg/L and HemosIL® 56 µg/L. Next, in 198 different samples, the concordance of VIDAS® DD (≥250 µg/L or <250 µg/L) was explored at the optimal cut-point of the other DD assays. The concordance was poor for all DD assays: Innovance® (kappa 0.38 (95% CI, 0.26-0.51)), Liatest® (kappa 0.38 (95% CI, 0.25-0.50)), HemosIL® (kappa 0.36 (95% CI, 0.23-0.49)) and Tina-quant® (kappa 0.30 (95% CI, 0.16-0.43)). Similar poor concordance was identified using half of the diagnostic DD cut-point for each tested assay: Innovance® (kappa 0.44 (95% CI, 0.32-0.56)), Liatest® (kappa 0.38 (95% CI, 0.25-0.51)), HemosIL® (kappa 0.04 (95% CI, -0.01-0.08)) and Tina-quant® (kappa 0.04 (95% CI, -0.004-0.07)). CONCLUSION: The "HERDOO2 rule" is the only prospectively validated clinical decision rule that can be used to identify low-risk women with unprovoked venous thrombosis who can safely discontinue anticoagulants. An important implementation issue is whether any commercial DD assay can be used in the HERDOO2 rule, and at what cut-point. Our analysis shows that the HemosIL®, Innovance®, Liatest® and Tina-quant® DD assays should not be used in the "HERDOO2" rule due to poor concordance with the VIDAS® DD assay and unacceptable misclassification of women at high and low risk of recurrent venous thrombosis.

Direct Oral Anticoagulant- or Warfarin-Related Major Bleeding: Characteristics, Reversal Strategies, and Outcomes From a Multicenter Observational Study.

BACKGROUND: Direct oral anticoagulants (DOACs) have expanded the armamentarium for antithrombotic therapy. Although DOAC-related major bleeding was associated with favorable outcomes compared with warfarin in clinical trials, warfarin effects were reversed in < 40% of cases, raising concerns about the generalizability of this finding. METHODS: Consecutive patients ≥ 66 years presented to five tertiary care hospitals across three cities in Ontario, Canada from October 2010 to March 2015 with diagnoses that included hemorrhage. Charts were screened for association with DOAC or warfarin use; eligible cases were abstracted and linked to administrative databases. RESULTS: Among 19,061 records screened, 2,002 (460 receiving DOAC, 1,542 receiving warfarin) were eligible. Reversal agents (72.9% vitamin K, 40.7% prothrombin complex concentrates) were frequently used in warfarin bleeding events. Red blood cell transfusions occurred more often in DOAC bleeding events than in warfarin events (52.0% vs 39.5%; adjusted relative risk [aRR], 1.32; 95% CI, 1.19-2.47). However, units of blood products transfused were not different between the two groups. Thirty-four DOAC cases (7.4%) received activated prothrombin complex concentrates or recombinant factor VIIa. In-hospital mortality was lower following DOAC bleeding events (9.8% vs 15.2%; aRR, 0.66; 95% CI, 0.49-0.89), although differences in 30-day mortality did not reach statistical significance (12.6% vs 16.3%; aRR, 0.79; 95% CI, 0.61-1.03). CONCLUSIONS: In this unselected cohort of patients with oral anticoagulant-related hemorrhage with high rates of warfarin reversal, in-hospital mortality was lower among DOAC-associated bleeding events. These findings support the safety of DOACs in routine care and present useful baseline measures for evaluations of DOAC-specific reversal agents.

Impact of platelet transfusion on toxicity and mortality after hematopoietic progenitor cell transplantation.

BACKGROUND: Thrombocytopenia occurs commonly after hematopoietic progenitor cell transplantation (HPCT) and is associated with potential morbidity and mortality. Few studies have examined the impact of platelet (PLT) transfusion on clinical outcomes in HPCT while optimal PLT transfusion strategies after HSCT remain uncertain. STUDY DESIGN AND METHODS: A retrospective single-center cohort study was conducted on 522 patients undergoing HPCT between January 2002 and December 2007. Associations between PLT transfusion events and clinical characteristics with transplant-related outcomes were assessed using univariate and multivariate analysis. RESULTS: Mean number of PLT transfusion events before Day +60 posttransplant was 7.5 (95% confidence interval, 6.7-8.4) with greater number of events after allogeneic compared with autologous HPCT (p < 0.01). Univariate and multivariate analysis confirmed that the number of PLT transfusion events was associated with increased 100-day nonrelapse mortality (p < 0.01), posttransplant length of hospital stay (p < 0.01), need for intensive care unit admission (p < 0.01), and number of organs affected by severe toxicity (p < 0.01). CONCLUSION: HPCT-related toxicity and mortality are associated with increased PLT transfusion events. Alternative strategies to reduce PLT transfusions after HPCT may warrant future study.

Further Evidence that Human Endogenous Retrovirus K102 is a Replication Competent Foamy Virus that may Antagonize HIV-1 Replication.

OBJECTIVE: The goals of the research were to determine if a foamy effect on macrophages was due to human endogenous retrovirus K102 (HERV-K102) replication, and to further address its potential significance in HIV-1 infection. METHODS: An RT-PCR HERV-K HML-2 pol method was used to screen the unknown HERV, and isolated bands were sent for sequencing. Confirmation of RNA expression was performed by a real time quantitative PCR (qPCR) pol ddCt method. Rabbit antibodies to Env peptides were used to assess expression by immunohistology and processing of Env by western blots. A qPCR pol ddCt method to ascertain genomic copy number was performed on genomic DNA isolated from plasma comparing HIV-1 exposed seronegative (HESN) commercial sex workers (CSW) to normal controls and contrasted with HIV-1 patients. RESULTS: HERV-K102 expression, particle production and replication were associated with foamy macrophage generation in the cultures of cord blood mononuclear cells under permissive conditions. A five-fold increased HERV-K102 pol genomic copy number was found in the HESN cohort over normal which was not found in HIV-1 positive patients (p=0.0005). CONCLUSIONS: This work extends the evidence that HERV-K102 has foamy virus attributes, is replication competent, and is capable of high replication rate in vivo and in vitro. This may be the first characterization of a replication-competent, foamy-like virus of humans. High particle production inferred by increased integration in the HESN cohort over HIV-1 patients raises the issue of the clinical importance of HERV-K102 particle production as an early protective innate immune response against HIV-1 replication.

Acute extravascular hemolytic transfusion reaction due to anti-Kpa antibody missed by electronic crossmatch.

BACKGROUND: Kpa antigen is a low incidence red blood cell antigen within the Kell system. Anti-Kpa alloantibody may be associated with acute and delayed hemolytic transfusion reactions. CASE STUDY: We report a case of a clinically significant acute extravascular hemolytic transfusion reaction mediated by previously unrecognized (and undetected) anti-Kpa alloantibody. This reaction occurred in a patient who met all criteria for electronic crossmatch, resulting in the transfusion of an incompatible red cell unit. RESULTS: Post-transfusion investigation showed the transfused red cell unit was crossmatch compatible at the immediate spin phase but was 3 + incompatible at the antiglobulin phase. No evidence of intravascular hemolysis was observed upon visual comparison of the pre- and post-transfusion peripheral blood plasma. Further testing showed the presence of anti-Kpa antibody. The clinical course of the patient included acute febrile and systemic reaction. CONCLUSION: Acute extravascular hemolytic transfusion reaction may occur due to undetected anti-Kpa alloantibody. Various strategies for crossmatching are discussed in the context of antibodies to low incidence antigens.

Stroke prenotification is associated with shorter treatment times for warfarin-associated intracerebral hemorrhage.

BACKGROUND: Warfarin-associated intracerebral hemorrhage (WAICH) is a devastating disease with increasing incidence. In this setting, treatment with prothrombin complex concentrates (PCC) is essential to correct coagulopathy. Yet despite the availability of coagulopathy correction strategies, significant treatment delays can occur in emergency departments (EDs), which may be overcome using stroke prenotification strategies. To explore this, we compared arrival-to-treatment times with PCC for WAICH between two different stroke response systems that used the same international normalized ratio (INR) correction protocol. METHODS: We established a registry of consecutive patients presenting with WAICH and treated with PCC presenting to two Canadian tertiary-care academic stroke centers: one with a stroke prenotification system, and one with a traditional ED assessment, treatment and referral system. In this comparative cohort design, we defined the WAICH diagnosis time as the earliest time point where both INR and CT were available. We compared median times from arrival to treatment, as well as arrival to diagnosis, and diagnosis to treatment. RESULTS: Between 2008 and 2010, we collected data from 123 consecutive patients with intracranial hemorrhage who received PCC for INR correction (79 from ED referral, and 44 prenotification). Onset-to-arrival times, demographics, Glasgow Coma Scale scores, and baseline INR were similar between the two systems. Arrival-to-treatment times were significantly shorter in the prenotification system as compared to the traditional ED referral system (135 vs. 267 min; p = 0.001), which was driven by both decreased arrival-to-diagnosis time (49 vs. 117 min; p = 0.006), as well as decreased diagnosis-to-treatment time (56 vs. 112 min; p < 0.001). Arrival-to-scan times and arrival-to-INR times were similarly shorter in the prenotification system (68 vs. 118 min and 20.5 vs. 47 min, respectively). CONCLUSION: Stroke prenotification was associated with shorter arrival-to-treatment times for emergent INR correction in patients with WAICH, which was driven by both faster diagnosis and treatment. Our results are consistent with those seen in ischemic stroke, suggesting that prenotification systems present an opportunity to optimize acute intracerebral hemorrhage therapy.

Outcomes of urgent warfarin reversal with frozen plasma versus prothrombin complex concentrate in the emergency department.

BACKGROUND: Physicians reverse patients' warfarin anticoagulation with frozen plasma or prothrombin complex concentrate. Our objective was to determine adverse event frequency after urgent reversal with frozen plasma versus the prothrombin complex concentrate Octaplex. METHODS AND RESULTS: This natural before-after retrospective cohort study in 2 tertiary care emergency departments compared anticoagulation reversal with frozen plasma (September 2006-August 2008) and with Octaplex (September 2008-August 2010), without other system changes. We included adult patients on warfarin with an international normalized ratio ≥1.5 who received frozen plasma or Octaplex. Our primary outcome was serious adverse events (death, ischemic stroke, myocardial infarction, heart failure, venous thromboembolism, or peripheral arterial thromboembolism) within 7 days. Secondary outcomes included time to international normalized ratio reversal, hospital length of stay, and red blood cells transfused within 48 hours. We included 149 patients receiving frozen plasma and 165 receiving Octaplex. The incidence of serious adverse events for the frozen plasma group was 19.5% compared with 9.7% for the Octaplex group (P=0.014; relative risk, 2.0; 95% confidence interval, 1.1-3.5). This remained significant after adjustment for baseline history and reason for treatment (P=0.038; adjusted relative risk, 1.85; 95% confidence interval, 1.03-3.3) in multivariable regression analysis. Median international normalized ratio reversal was 11.8 hours with frozen plasma and 5.7 hours with Octaplex (P<0.0001). Mean red cell transfusion was 3.2 with frozen plasma and 1.4 with Octaplex (P<0.0001). CONCLUSIONS: Octaplex for urgent reversal of warfarin resulted in faster reversal and lower red cell transfusion requirement with fewer adverse events than frozen plasma.

Insights into origins of Human T-cell Lymphotropic Virus Type 1 based on new strains from aboriginal people of Canada.

The causes of the worldwide distribution of Human T-cell Lymphotropic Virus Type 1 (HTLV-1) remain incompletely understood, with competing hypotheses regarding the number and timing of events leading to intercontinental spread on historical and prehistoric timescales. Ongoing discovery of this virus in aboriginal populations of Asia and the Americas has been the main source of evidence for the latter. We conducted molecular phylogenetic and dating analyses for 13 newly reported HTLV-1 strains from Canada. We analyzed two full-length proviral genomes from aboriginal residents of Nunavut (an autonomous territory in Northern Canada including most of the Canadian Arctic), 11 long-terminal-repeat (LTR) sequences from aboriginal residents of British Columbia's Pacific coast, and 2 LTR sequences from non-aboriginal Canadians. Phylogenetic analysis demonstrated a well-supported affinity between the two Nunavut strains and two East Asian strains, suggesting the presence of an Asian-American sublineage within the widespread "transcontinental" subgroup A clade of HTLV-1 Cosmopolitan subtype a. This putative sublineage was estimated to be 5400-11,900 years in age, consistent with a long-term presence of HTLV-1 in aboriginal populations of the Canadian Arctic. Phylogenetic affinities of the other 11 Canadian HTLV-1 aboriginal strains were diverse, strengthening earlier evidence for multiple incursions of this virus into coastal aboriginal populations of British Columbia. Our results are consistent with the hypothesis of ancient presence of HTLV-1 in aboriginal populations of North America.

Poor prognosis in warfarin-associated intracranial hemorrhage despite anticoagulation reversal.

BACKGROUND AND PURPOSE: Anticoagulant-associated intracranial hemorrhage (aaICH) presents with larger hematoma volumes, higher risk of hematoma expansion, and worse outcome than spontaneous intracranial hemorrhage. Prothrombin complex concentrates (PCCs) are indicated for urgent reversal of anticoagulation after aaICH. Given the lack of randomized controlled trial evidence of efficacy, and the potential for thrombotic complications, we aimed to determine outcomes in patients with aaICH treated with PCC. METHODS: We conducted a prospective multicenter registry of patients treated with PCC for aaICH in Canada. Patients were identified by local blood banks after the release of PCC. A chart review abstracted clinical, imaging, and laboratory data, including thrombotic events after therapy. Hematoma volumes were measured on brain CT scans and primary outcomes were modified Rankin Scale at discharge and in-hospital mortality. RESULTS: Between 2008 and 2010, 141 patients received PCC for aaICH (71 intraparenchymal hemorrhages). The median age was 78 years (interquartile range, 14), 59.6% were male, and median Glasgow Coma Scale was 14. Median international normalized ratio was 2.6 (interquartile range, 2.0) and median parenchymal hematoma volume was 15.8 mL (interquartile range, 31.8). Median post-PCC therapy international normalized ratio was 1.4: 79.5% of patients had international normalized ratio correction (<1.5) within 1 hour of PCC therapy. Patients with intraparenchymal hemorrhage had an in-hospital mortality rate of 42.3% with median modified Rankin Scale of 5. Significant hematoma expansion occurred in 45.5%. There were 3 confirmed thrombotic complications within 7 days of PCC therapy. CONCLUSIONS: PCC therapy rapidly corrected international normalized ratio in the majority of patients, yet mortality and morbidity rates remained high. Rapid international normalized ratio correction alone may not be sufficient to alter prognosis after aaICH.

Prothrombin complex concentrate for the urgent reversal of warfarin. Assessment of a standard dosing protocol.

BACKGROUND: Octaplex®, a six factor prothrombin complex concentrate (PCC), has recently been approved for use in Canada. The optimal dose of Octaplex has yet to be established and our study was designed to monitor the efficacy of a low standard dose. STUDY DESIGN AND METHODS: Patients on warfarin treatment in need of urgent reversal for bleeding, invasive procedures or surgery were given a standard dose of 40 ml (1000 IU FIX, 14 IU/kg). We conducted a retrospective chart review of 231 patients. RESULTS: Patients given concurrent frozen plasma (FP) for reversal were eliminated from the study. Overall, 150 patients were reviewed and divided into three groups: (1) non-CNS bleeders, (2) CNS bleeders, and (3) non-bleeders. Correction of INR to 1.5 or less was achieved to the same extent in each group. Patients with active bleeding had the least successful bleeding cessation and patients with intracranial bleeding had the most dismal outcome compared to non-intracranial bleeders. CONCLUSIONS: Our data suggests that Octaplex, when given as a low standard dose is effective at INR reversal with 76% of our patients correcting to an INR of 1.5 or less. It appears that this dose is sufficient for non-bleeding patients. Bleeding patients may benefit most from a dose increase to achieve more complete reversal and patients with intracranial bleeding should achieve more complete reversal within 2h of presentation.

Increased apoptosis in cryopreserved autologous hematopoietic progenitor cells collected by apheresis and delayed neutrophil recovery after transplantation: a nested case-control study.

BACKGROUND AIMS: Delayed neutrophil recovery following autologous hematopoietic stem cell transplantation (aHSCT) increases transplant-related morbidity. Apoptosis induced by cryopreservation and thawing of hematopoietic progenitor cells collected by apheresis (HPC-A) was investigated in this nested case-control study as a factor associated with delayed neutrophil recovery following aHSCT. METHODS: Among patients with lymphoma who underwent aHSCT between 2000 and 2007 (n = 326), 13 cases of primary delayed neutrophil recovery and 22 age- and sex-matched controls were identified. Apoptosis and viability were measured using multiparameter flow cytometry, and colony-forming capacity was determined using semi-solid methylcellulose assays. RESULTS: HPC-A grafts from cases and controls had similar percentages of viable mononuclear cells (MNC) and CD34+ progenitor cells, as determined by standard 7AAD dye exclusion methods measured before and after cryopreservation. Patients with delayed neutrophil recovery received increased numbers of apoptotic MNC (P = 0.02) but similar numbers of apoptotic CD34+ cells per kilogram measured after thawing. Apoptosis was more pronounced in MNC compared with CD34+ cells after thawing, and apoptosis was negligible in freshly collected HPC-A products. Patients with delayed neutrophil recovery had fewer total colony-forming unites (CFU) and CFU-granulocyte-macrophages (GM) per 10(5) viable post-thaw MNC compared with controls (P < 0.05). CONCLUSIONS: Increased numbers of apoptotic MNC in thawed HPC-A products are associated with delayed neutrophil recovery after aHSCT. Studies that address factors contributing to increased apoptosis are needed, and measuring apoptosis in thawed HPC-A may have a role in the assessment of graft adequacy.

Fibrin glues in combination with mesenchymal stem cells to develop a tissue-engineered cartilage substitute.

Damage of cartilage due to traumatic or pathological conditions results in disability and severe pain. Regenerative medicine, using tissue engineering-based constructs to enhance cartilage repair by mobilizing chondrogenic cells, is a promising approach for restoration of structure and function. Fresh fibrin (FG) and platelet-rich fibrin (PR-FG) glues produced by the CryoSeal(®) FS System, in combination with human bone marrow-derived mesenchymal stem cells (BM-hMSCs), were evaluated in this study. We additionally tested the incorporation of heparin-based delivery system (HBDS) into these scaffolds to immobilize endogenous growth factors as well as exogenous transforming growth factor-ß(2). Strongly, CD90+ and CD105+ hMSCs were encapsulated into FG and PR-FG with and without HBDS. Encapsulation of hMSCs in PR-FG led to increased expression of collagen II gene at 2.5 weeks; however, no difference was observed between FG and PR-FG at 5 weeks. The incorporation of HBDS prevented the enhancement of collagen II gene expression. BM-hMSCs in FG initially displayed enhanced aggrecan gene expression and increased accumulation of Alcian blue-positive extracellular matrix; incorporation of HBDS into these glues did not improve aggrecan gene expression and extracellular matrix accumulation. The most significant effect on cartilage marker gene expression and accumulation was observed after encapsulation of hMSCs in FG. We conclude that FG is more promising than PR-FG as a scaffold for chondrogenic differentiation of hMSCs; however, immobilization of growth factors inside these fibrin scaffolds with the HBDS system has a negative impact on this process. In addition, BM-hMSCs are valid and potentially superior alternatives to chondrocytes for tissue engineering of articular cartilage.