A Transfusion Regimen With Same-donor Packed Red Blood Cells Reduces Exposure to Multiple Blood Donors in Craniosynostosis Surgery.

In major craniosynostosis surgery with moderate to severe blood loss, patients may be exposed to multiple donors. We have previously reported a method for reducing donor exposure using mixed pediatric units including plasma. To further reduce donor exposure, we used plasma-free divided pediatric units. The study aimed to investigate the feasibility of the new strategy for reducing donor exposure. This prospective observational study recruited children younger than 1 year who were scheduled for nonsyndromic craniosynostosis surgery. One adult red blood cell unit was divided into 4 equal units on the day before the operation for use intra- or postoperatively. Number of donor exposures, estimated blood loss, crystalloid, colloid, and blood product volumes, and coagulation parameters were evaluated. Nineteen infants were included. The mean estimated blood loss was 19 (3) mL/kg and the transfusion volume was 17 (7) mL/kg. The median donor exposure per patient was 1 (range, 1-3). During surgery, all infants received at least one DPU. Two infants received transfusions from more than one donor during the intraoperative period. In the first 24 hours postoperatively, 14 infants received transfusion; 10 received only DPUs, whereas 4 received from multiple donors. In all, multiple donor exposure was prevented in 14 of 19 infants. Postoperative Pk-INR was 1.33 (0.16); no plasma or platelets were transfused. The plasma-free DPU transfusion protocol may be useful to reduce donor exposure in open craniosynostosis surgery in infants.

A novel nonsense variant in RHAG underlies a Nordic Rhnull phenotype.

BACKGROUND AND OBJECTIVES: The extremely rare Rhnull phenotype is characterized by the absence of all Rh antigens on erythrocytes. It is divided into the regulator and amorph types based on the underlying genetic background. The more common regulator type depends on critical variants silencing RHAG, which encodes RhAG glycoprotein, necessary for RhD/RhCE expression. Rhnull cells have altered expression of glycophorin B and LW glycoprotein. MATERIALS AND METHODS: Four unrelated Rhnull individuals were investigated. Serological testing was performed according to standard blood bank practice. RHD/RHCE and S/s allele-specific Polymerase chain reaction (PCR) genotyping was done on genomic DNA using in-house PCR assays. RHAG, and in some cases also RHD/RHCE, were sequenced. Initial s phenotyping results triggered additional serological investigation. RESULTS: Anti-Rh29 was identified in all four individuals. Extended typing with anti-S and anti-s showed that the three samples predicted to type as s+ failed to react with 2 of 5 anti-s. Sequence analysis of all 10 RHAG exons and the immediate intron/exon boundaries revealed a single nucleotide variant in the 3'-end of intron 6, c.946 -2a>g in all samples. RHD/RHCE showed no alterations. CONCLUSION: A novel Nordic Rhnull allele was identified. In addition, it was shown that s+ Rhnull red blood cells are not only U- but also have qualitative changes in their s antigen expression.

PET Imaging of Neutrophil Elastase with 11C-GW457427 in Acute Respiratory Distress Syndrome in Pigs.

Today, there is a lack of clinically available imaging techniques to detect and quantify specific immune cell populations. Neutrophils are one of the first immune cells at the site of inflammation, and they secrete the serine protease neutrophil elastase (NE), which is crucial in the fight against pathogens. However, the prolonged lifespan of neutrophils increases the risk that patients will develop severe complications, such as acute respiratory distress syndrome (ARDS). Here, we evaluated the novel radiolabeled NE inhibitor 11C-GW457427 in a pig model of ARDS, for detection and quantification of neutrophil activity in the lungs. Methods: ARDS was induced by intravenous administration of oleic acid to 5 farm pigs, and 4 were considered healthy controls. The severity of ARDS was monitored by clinical parameters of lung function and plasma biomarkers. Each pig was studied with 11C-GW457427 and PET/CT, before and after pretreatment with the NE inhibitor GW311616 to determine in vivo binding specificity. PET image data were analyzed as SUVs and correlated with immunohistochemical staining for NE in biopsies. Results: The binding of 11C-GW457427 was increased in pig lungs with induced ARDS (median SUVmean, 1.91; interquartile range [IQR], 1.67-2.55) compared with healthy control pigs (P < 0.05 and P = 0.03, respectively; median SUVmean, 1.04; IQR, 0.66-1.47). The binding was especially strong in lung regions with high levels of NE and ongoing inflammation, as verified by immunohistochemistry. The binding was successfully blocked by pretreatment of an NE inhibitor drug, which demonstrated the in vivo specificity of 11C-GW457427 (P < 0.05 and P = 0.04, respectively; median SUVmean, 0.60; IQR, 0.58-0.77). The binding in neutrophil-rich tissues such as bone marrow (P < 0.05 and P = 0.04, respectively; baseline median SUVmean, 5.01; IQR, 4.48-5.49; block median SUVmean, 1.57; IQR, 0.95-1.85) and spleen (median SUVmean, 2.14; IQR, 1.19-2.36) was also high in all pigs. Conclusion: 11C-GW457427 binds to NE in a porcine model of oleic acid-induced lung inflammation in vivo, with a specific increase in regional lung, bone marrow, and spleen SUV. 11C-GW457427 is a promising tool for localizing, tracking, and quantifying neutrophil-facilitated inflammation in clinical diagnostics and drug development.

[Awareness of risk for transfusion reactions important for appropriate treatment]. / Risk för komplikationer viktig att väga in inför transfusioner.

Blood transfusions are still associated with risk for adverse events despite a long tradition for improvement of safety. The incidence of reactions is reported to be about 78/100 000 transfusions with 25 % of these being serious. Some types of reactions are rare and may thus be unrecognised.  Transfusion reactions are grouped into non-infectious acute reactions (such as acute haemolytic reactions due to ABO incompatibility or Transfusion Related Circulatory Overload (TACO)) and delayed reactions. Infectious complications in transfusion medicine include emerging viruses like Hepatitis E and West Nile-Virus, not routinely tested.  Awareness is important for appropriate diagnosis and treatment. Transfusion reactions should be reported to and investigated by the transfusion medicine department issuing the product. It is mandatory to report serious transfusion reactions to the competent authority.

Patterns of blood use in Sweden from 2008 to 2017: A nationwide cohort study.

BACKGROUND: Transfusion patterns in Sweden have not been characterized on a nationwide level. STUDY DESIGN AND METHODS: We conducted a nationwide descriptive cohort study in Sweden from 2008 to 2017. Data on blood donors, donations, component manufacture, transfusions, and transfused patients were extracted from Swedish portion of the Scandinavian Donations and Transfusions (SCANDAT3-S) database. RESULTS: A total of 708 436 patients received 5 587 684 red cell, plasma, or platelet transfusions during the study period. The age-standardized transfusion rate decreased markedly during the study period for red cell units (from 53 to 39 units/1000 persons) and plasma units (from 11 to 4.9 units/1000 persons), but remained relatively constant for platelet concentrates. The transfusion rate was 30%-40% higher in males than in females in the first year of life, and higher in males over 45 years than in females. Between age 20 and 45, the majority of red cells were transfused to female patients with obstetric indications, whereas trauma was the predominant indication for male contemporaries. In females over 80 years, the largest proportion of red cells were administered due to trauma. Overall, hematological patients received 36% of all platelet units. There were large regional differences in transfusion rates for red cell units, ranging from less than 30 to greater than 60/1000 persons. CONCLUSION: Transfusion rates in Sweden remain high but have decreased strikingly during the study period - with the exception of platelet transfusions. Based on the available data, it is difficult to draw firm conclusions about whether transfusion rates can be further reduced.

Perfusion of Porcine Kidneys With Macromolecular Heparin Reduces Early Ischemia Reperfusion Injury.

BACKGROUND: Previously, we have been able to demonstrate the possibility of coating the inner surface of the renal arteries in porcine kidneys with a heparin conjugate during hypothermic machine perfusion (HMP). The purpose of this study was to assess the efficacy of this treatment in reducing early ischemia-reperfusion injury. METHOD: Brain death was induced in male landrace pigs by stepwise volume expansion of an epidural balloon catheter until negative cerebral perfusion pressure (CPP) was obtained. Both kidneys (matched pairs; n = 6 + 6) were preserved for 20 hours by HMP during which 50 mg heparin conjugate was added to one of the HMP systems (treated group). A customized ex vivo normothermic oxygenated perfusion (NP) system with added exogenous creatinine was used to evaluate early kidney function. Blood, urine and histological samples were collected during the subsequent 3 hours of NP. RESULTS: Kidney weight was lower at the end of NP (P = 0.017) in the treated group compared with control kidneys. The rate of decline in creatinine level was faster (P = 0.024), total urinary volume was higher (P = 0.031), and the level of urine neutrophil gelatinase-associated lipocalin (NGAL) was lower (P = 0.031) in the treated group. Histologically, less tubular changes were seen (P = 0.046). During NP intrarenal resistance remained lower (P < 0.0001) in the treated group. CONCLUSIONS: Perfusion of porcine kidneys with heparin conjugate during HMP reduces preservation injury and improves organ function shortly after reperfusion. No increased risk of bleeding was seen in this setup. This protective strategy may potentially improve the quality of transplanted kidneys in the clinical setting.

Patient was wrongly diagnosed and repeatedly treated for immune thrombocytopenia for 50 years / Patient fick rätt diagnos efter 50 års behandling för immunologisk trombocytopeni - ­ Hade ärftlig trombocytopeni.

We report on a patient with inherited macrothrombocytopenia, MYH9 related disease (MYH9-RD). The patient was wrongly diagnosed and repeatedly treated for immune thrombocytopenia (ITP) for nearly 50 years. Cases of misdiagnosed MYH9-RD and other hereditary thrombocytopenias have been described previously. Typical clinical features such as renal failure and/or progressive loss of hearing should give grounds to suspect hereditary thrombocytopenia. Initial laboratory diagnosis can start with a simple blood smear followed by immunohistochemistry and genotyping. Therapy with thrombopoietin receptor agonists may be beneficial in selected cases of MYH9-RD. ITP treatments including splenectomy are not indicated and may cause harm.

The 99th percentile and imprecision of point-of-care cardiac troponin I in comparison to central laboratory tests in a large reference population.

OBJECTIVES: Determination of cardiac troponin (cTn) is central in the emergency department (ED) for the diagnosis of myocardial infarction. In view of adverse effects of long waiting time on patient outcome, implementation of point-of-care-testing (POCT) is suggested if the turn-around-time is longer than 60min. The present study aimed to determine the 99th percentile and imprecision of two POCT in a healthy population measuring cTnI and cTnT and compare these analytical characteristics against three central laboratory test (CLT) for cTnI. DESIGN & METHODS: CTnI and cTnT were determined in parallel by means of the AQT90 FLEX analyzer in about 2250 plasma samples from individuals with known health status. Results were compared to previously determined performance data of three CLT. RESULTS: The 99th percentile of cTnI in the POCT was determined at 19ng/L, the lowest concentration with an imprecision of 10% was reached at 22ng/L while an imprecision of 20% was reached at 13ng/L. Age, sex, or physical activity did not affect the 99th percentile of cTnI. Compared to CLT the AQT90 cTnI POCT the analytical performance was equivalent. The cTnT POCT could not be assessed due a considerable number of high values and an inadequate imprecision profile. CONCLUSION: While the cTnI POCT showed analytical performance comparable to CLT, the results of the cTnT assay on the same device did not suffice to determine a reliable 99th percentile. The present evaluation supports the usage of the cTnI POCT, but application of the cTnT POCT needs further evaluation.

An evaluation of the mixed pediatric unit for blood loss replacement in pediatric craniofacial surgery.

BACKGROUND: Surgical correction for craniosynostosis is often associated with significant perioperative hemorrhage. We implemented a transfusion strategy with a strict protocol including transfusion triggers, frequent assessment of coagulation tests, and the use of a novel transfusion unit, the mixed pediatric unit. AIM: The aim of the study was to evaluate if the applied transfusion strategy could reduce total blood loss and number of blood donors. METHODS: Children <1 year old admitted for craniosynostosis surgery were included for the study. On the day before surgery, an adult red blood cell unit was mixed with plasma and split into two mixed pediatric units-one intended for intraoperative use and the other saved for the postoperative period. A series of blood samples were obtained for standard coagulation parameters as well as thromboelastography to evaluate potential coagulopathy. Estimated blood loss, the number of additional standard packed red cell units opened in the first 24 h after surgery, the volume of fluid administered, and the total transfusion volumes were compared to a historical control group with similar age and characteristics. RESULTS: Nineteen infants were included in the study group, and were compared to 21 historical controls. There was a significant reduction of intraoperative transfusion volume. Twelve patients were transfused postoperatively, but in 8 of these additional exposure to packed red cell donor blood was avoided by using the saved mixed pediatric unit. In the historical controls, a total of 10 packed red cell units were used in nine patients postoperatively. No additional transfusions of plasma, platelets, fibrinogen, or tranexamic acid were needed in either group, and the coagulation parameters including thromboelastography remained within their respective normal ranges in the study group. CONCLUSION: For craniofacial surgery in infants, moderate perioperative blood loss and avoidance of coagulopathy is possible when a multifactorial approach is implemented. In this setting, intraoperative, but not total perioperative blood loss was reduced with the studied protocol. The study indicates that there may be a role for mixed pediatric units to reduce exposure to multiple donors although the reduction in total donor exposure was not significant.

Standardizing the freeze-thaw preparation of growth factors from platelet lysate.

BACKGROUND: Over the past decades, the focus on the regenerative properties of platelets (PLTs) has intensified and many PLT-derived growth factors are readily used in medical settings. A general lack of standardization in the preparation of these growth factors remains, however, and this study therefore examines the dynamics of growth factors throughout the freeze-thaw procedure. STUDY DESIGN AND METHODS: Plateletpheresis (PA) and PLT-poor plasma (PPP) samples were collected from 10 healthy donors. PA was lysed to produce PLT lysate (PL) for 1, 3, 5, 10, and 30 freeze-thaw cycles. The resulting growth factor and cytokine concentrations from PPP, PA, and PL of different cycles were analyzed and compared using enzyme-linked immunosorbent assay and multiplex bead assays. RESULTS: PL produced by the freeze-thaw procedure resulted in approximately four- to 10-fold enrichment of transforming growth factor-ß1, epidermal growth factor, PLT-derived growth factor (PDGF)-AB/BB, PLT factor-4, and fibroblast growth factor-2. The increase in concentrations plateaued at Cycles 3 and 5 and in some cases declined with further cycles. The concentrations of insulin-like growth factor-1, hepatocyte growth factor, vascular endothelial growth factor, and bone morphogenetic protein-2 in PL were essentially comparable to those in PPP. CONCLUSION: Using the freeze-thaw method, optimal preparation of PL with regard to the concentration of growth factors was achieved at Cycles 3 to 5. Based on our findings, the clinical significance of using a greater number of cycles is likely limited.

Analysis of thromboelastography, PT, APTT and fibrinogen in intraosseous and venous samples-an experimental study.

BACKGROUND: Laboratory analysis of coagulation is often important in emergencies. If vascular access is challenging, intraosseous catheterization may be necessary for treatment. We studied the analysis of coagulation parameters in intraosseous aspirate during stable conditions and after major haemorrhage in a porcine model. METHODS: Ten anesthetized pigs received central venous and intraosseous catheters and samples were taken for analysis of thromboelastography (TEG), prothrombin time (PT), activated partial thromboplastin time (APTT) and fibrinogen concentration. Analyses were repeated after removal of 50 % of the calculated blood volume and resuscitation with crystalloid. Intraosseous and venous values were compared. RESULTS: Bleeding and resuscitation resulted in haemodilution and hypotension. Median TEG reaction time was shorter in intraosseous than in venous samples before (1.6 vs 4.6 min) and after (1.6 vs 4.7 min) haemodilution. Median maximal amplitude was smaller in intraosseous samples at baseline (68.3 vs 76.4 mm). No major differences were demonstrated for the other TEG parameters. The intraosseous samples often coagulated in vitro, making analysis of PT, APTT and fibrinogen difficult. After haemodilution, TEG maximal amplitude and α-angle, and fibrinogen concentration, were decreased and PT increased. DISCUSSION: The intraosseous samples were clinically hypercoagulable and the TEG demonstrated a shortened reaction time. The reason for this may hypothetically be found in the composition of the IO aspirate or in the sampling technique. After 50 % haemorrhage and haemodilution, a clinically relevant decrease in fibrinogen concentration and a lower TEG maximal amplitude were observed. CONCLUSIONS: Although the sample is small, these data indicate that intraosseous samples are hypercoagulable, which may limit their usefulness for coagulation studies. Major haemodilution only moderately affected the studied parameters.

Impact of physical activity of individuals and creatine kinase on 99th percentiles of troponin I assays.

Determination of cardiac troponin I (cTnI) is one central means for diagnosis of myocardial infarction. Assay performance of three troponin I assays was compared previously in a large reference population detecting sex-differences in the 99th percentile only for the Dimension Vista cTnI assay. The present study examined the underlying effects. Values for cTnI were reused. Creatine kinase (CK) activity was determined in 2358 samples from blood donors. Information on physical activity was evaluated from health questionnaires. Using quantile regression data were analysed to investigate the impact of sex, physical activity, and CK on the 99th percentile of the cTnI assay. We report significant sex-differences for the 99th percentile of cTnI. Physical activity was significantly associated with cTnI values. Strong association of CK activity with cTnI values was detected only in men. Adjustment for CK in quantile regression abolished sex-differences in the 99th percentile. Two other contemporary sensitive cTnI assays were not relevantly affected by physical activity or CK. Sex-differences in the 99th percentile for the Dimension Vista cTnI assay arise from a positive association between cTnI and physical activity and were abrogated when data were adjusted for CK activity. These findings should be taken into account when using this assay.

Composition of growth factors and cytokines in lysates obtained from fresh versus stored pathogen-inactivated platelet units.

BACKGROUND: Platelet lysate is a readily available source of growth factors, and other mediators, which has been used in a variety of clinical applications. However, the product remains poorly standardized and the present investigation evaluates the composition of platelet lysate obtained from either fresh or stored pathogen-inactivated platelet units. MATERIALS AND METHODS: Platelet pooled units (n = 10) were obtained from healthy blood donors and tested according to standard procedures. All units were pathogen inactivated using amotosalen hydrochloride and UVA exposure. Platelet lysate was subsequently produced at two separate time-points, either from fresh platelet units or after 5 days of storage, by repeated freeze-thaw cycles. The following mediators were determined at each time-point: EGF, FGF-2, VEGF, IGF-1, PDGF-AB/BB, BMP-2, PF4, TGF-ß isoform 1, IL-1ß, IL-2, IL-6, IL-10, IL-12p70, 1L-17A, TNF-α, and IFN-γ. RESULTS: The concentration of growth factors and cytokines was affected by time in storage. Notably, TGF-ß, PDGF-AB/BB, and PF4 showed an increase of 27.2% (p < 0.0001), 29.5% (p = 0.04) and 8.2% (p = 0.0004), respectively. A decrease was seen in the levels of IGF-1 and FGF-2 with 22% (p = 0.041) and 11% (p = 0.01), respectively. Cytokines were present only in very low concentrations and all other growth factors remained stable with time in storage. CONCLUSION: The composition of mediators in platelet lysate obtained from pathogen-inactivated platelet units differs when produced from fresh and stored platelet units, respectively. This underscores the need for further standardization and optimization of this important product, which potentially may influence the clinical effects.

Alternative diagnosis to heparin-induced thrombocytopenia in two critically ill patients despite a positive PF4/heparin-antibody test.

Thrombocytopenia can cause diagnostic challenges in patients who have received heparin. Heparin-induced thrombocytopenia (HIT) is often considered in the differential diagnosis, and a positive screening can be mistaken as confirmation of the disorder. We present two patients who both received low-molecular-weight heparin for several days. In the first patient, clinical judgment rejected the suspicion of HIT despite a positive screening assay, and treatment for the alternative diagnosis of post-transfusion purpura was correctly initiated. In the second patient, the inaccurate diagnosis HIT was pursued due to a positive screening assay, while the alternative diagnosis of drug-dependent thrombocytopenia caused by piperacillin/tazobactam was rejected. This resulted in re-exposure to piperacillin/tazobactam which caused a second episode of severe thrombocytopenia. A positive screening assay for platelet factor 4/heparin-antibody should be verified by a functional assay, especially in patients with low pretest probability for HIT.

Comparison of the 99th percentiles of three troponin I assays in a large reference population.

BACKGROUND: The IFCC Task Force on Clinical Applications of Cardiac Biomarkers suggests comparing several contemporary sensitive troponin assays in the same, sufficiently large reference population. METHODS: Three contemporary sensitive assays were used to measure troponin I concentration in samples from a uniquely large healthy population (2404 individuals) and in a sub-group with tighter inclusion criteria of 908 individuals. The 99th percentiles were calculated using quantile regression which takes the entire population into account. RESULTS: The 99th percentile for the ARCHITECT STAT Troponin I assay was 21 ng/L, 31 ng/L for the ADVIA Centaur Troponin I-Ultra assay and 28 ng/L for the Dimension Vista cTnI assay. Significantly higher values were found in males than in women only in the Dimension Vista cTnI assay and in the subgroup for the ARCHITECT STAT Troponin I assay. CONCLUSIONS: Quantile regression provides a tool to accurately estimate the 99th percentile and establish a continuous function of the relation between the 99th percentile and the age and gender. There was no age dependency demonstrated. A gender difference was found in one assay but inconclusive in another and not demonstrated in a third.