RESUMO
BACKGROUND: Platelet transfusion is associated with logistical problems with the national storage guidelines of platelets. This results in decreased function in vivo as a result of the platelet storage lesion, and complications such as allergic or hemolytic reactions and thrombosis. We evaluated a new, freshly prepared platelet modified lysate (PML) product designed to be more procoagulant than fresh and stored platelets. METHODS: Fresh platelets were concentrated, sonicated, and centrifuged to produce PML. Samples of both washed and unwashed PML were evaluated for particle size, concentration, and activity, and then tested for clot kinetics and thrombin generation. PML samples were also stored at various temperatures for durations up to 6 months and evaluated for clot kinetics and thrombin generation throughout. RESULTS: PML showed significantly higher concentration of platelet microparticles, increased procoagulant properties, and increased thrombin generation as compared to fresh and stored platelets. In addition, PML maintained its clot kinetics over a 6-month storage period with variable storage conditions. CONCLUSIONS: The newly proposed PML product is more procoagulant, stable, and has additional potential applications than currently available platelet products. Further studies will be performed to assess its functions in vivo and to assess thrombotic potential.
Assuntos
Coagulação Sanguínea/efeitos dos fármacos , Plaquetas/química , Micropartículas Derivadas de Células/química , Coagulantes , Coagulantes/química , Coagulantes/farmacologia , Avaliação Pré-Clínica de Medicamentos , Humanos , Transfusão de PlaquetasRESUMO
BACKGROUND: Relationships between red blood cell (RBC) transfusion, circulating cell-free heme, and clinical outcomes in critically ill transfusion recipients are incompletely understood. The goal of this study was to determine whether total plasma heme increases after RBC transfusion and predicts mortality in critically ill patients. STUDY DESIGN AND METHODS: This was a prospective cohort study of 111 consecutive medical intensive care patients requiring RBC transfusion. Cell-free heme was measured in RBC units before transfusion and in the patients' plasma before and after transfusion. RESULTS: Total plasma heme levels increased in response to transfusion, from a median (interquartile range [IQR]) of 35 (26-76) µmol/L to 47 (35-73) µmol/L (p < 0.001). Posttransfusion total plasma heme was higher in nonsurvivors (54 [35-136] µmol/L) versus survivors (44 [31-65] µmol/L, p = 0.03). Posttransfusion total plasma heme predicted hospital mortality (odds ratio [95% confidence interval] per quartile increase in posttransfusion plasma heme, 1.76 [1.17-2.66]; p = 0.007). Posttransfusion total plasma heme was not correlated with RBC unit storage duration and weakly correlated with RBC unit cell-free heme concentration. CONCLUSIONS: Total plasma heme concentration increases in critically ill patients after RBC transfusion and is independently associated with mortality. This transfusion-associated increase in total plasma heme is not fully explained by RBC unit storage age or cell-free heme content. Additional studies are warranted to define mechanisms of transfusion-related plasma heme accumulation and test prevention strategies.
Assuntos
Estado Terminal/mortalidade , Estado Terminal/terapia , Transfusão de Eritrócitos/efeitos adversos , Heme/metabolismo , Adulto , Idoso , Estudos de Coortes , Transfusão de Eritrócitos/métodos , Transfusão de Eritrócitos/mortalidade , Feminino , Heme/análise , Mortalidade Hospitalar , Humanos , Unidades de Terapia Intensiva , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Prospectivos , Resultado do TratamentoRESUMO
BACKGROUND: Normal saline has been the fluid of choice for resuscitation, rehydration and fluid replacement during plasma or red cell exchange/cytapheresis. There are increased concerns about its clinical effects and data showing it causes more haemolysis in vitro than buffered solutions such as Plasma-Lyte A. METHODS: We investigated whether normal saline or Plasma-Lyte A was associated with greater haemolysis during hours of in vitro incubation with both normal red cells and samples from patients with sickle cell anaemia. RESULTS: Sickle red cells haemolysed more than normal red cells did in both crystalloid solutions. The results of 24-hour exposure to saline were particularly striking (median of 163 mg/dl (IQ range 105-247) for sickle red cells vs. 53 (48-92) for normal red cells (P < 0·0001). In patient samples containing variable quantities of haemoglobin S red cells, increased haemoglobin S was associated with increased haemolysis. This effect was greater for normal saline than Plasma-Lyte A (P = 0·12). CONCLUSIONS: These in vitro models demonstrate that short-term ex vivo exposure of sickle red cells to normal saline leads to greater haemolysis than short-term exposure of normal red cells, and this effect is exacerbated by normal saline. Whether use of normal saline causes increased haemolysis in vivo is unknown. Given recent evidence that normal saline increases renal failure and mortality in critically ill patients, further studies are urgently needed.
Assuntos
Eletrólitos/química , Eritrócitos/efeitos dos fármacos , Hemólise/efeitos dos fármacos , Solução Salina/química , Anemia Falciforme/tratamento farmacológico , Anticoagulantes , Transfusão de Sangue , Estado Terminal , Contagem de Eritrócitos , Hidratação , Testes Hematológicos , Hemoglobina Falciforme/análise , Humanos , Segurança do Paciente , Plasma , Ressuscitação , Cloreto de Sódio/químicaRESUMO
INTRODUCTION: Chorionic cysts of the chorion laeve, fetal chorionic plate, septum, and free membranes have been associated with placental hypoxia, but they have no clear clinical significance. Although immunohistochemistry has identified fibronectin and collagen IV in cyst fluid, the contents have yet to be fully characterized. METHODS: Placental chorionic cysts (N = 10) were sampled by fluid extraction and hemotoxylin and eosin-stained sections. Amniotic fluid samples (N = 8) were obtained from pregnant women who had cytogenetic evaluation. The content of the cysts was tested for thrombogenicity using thromboelastography. The cyst content was tested by Luminex multiplex and ELISA assays and for known prothrombotic and proinflammatory factors. RESULTS: We identified cysts, especially those in the chorionic plate, adjacent to intervillous thrombi with apparent cyst rupture. Thromboelastography revealed a significantly shorter R time compared to whole blood control samples. Concentration of creatinine, α-fetoprotein, and surfactant D in the cyst fluid differed significantly from amniotic fluid. Cyst fluids had a significantly higher expression of all prothrombotic and some proinflammatory factors. DISCUSSION: Our data provide the first evidence that chorionic cyst fluid is prothrombotic and different from amniotic fluid. The association of ruptured cysts with adjacent thrombi and the prothrombotic properties of cyst fluid suggest a causal relationship; however, further studies are needed.
Assuntos
Doenças Placentárias/patologia , Placenta/patologia , Trombose/patologia , Líquido Amniótico/metabolismo , Córion/patologia , Líquido Cístico/metabolismo , Cistos/patologia , Feminino , Humanos , Gravidez , TromboelastografiaRESUMO
BACKGROUND: There are data suggesting that free hemoglobin (Hb), heme, and iron contribute to infection, thrombosis, multiorgan failure, and death in critically ill patients. These outcomes may be mitigated by haptoglobin. STUDY DESIGN AND METHODS: 164 consecutively treated children undergoing surgery for congenital heart disease were evaluated for associations between free Hb and haptoglobin and clinical outcomes, physiologic metrics, and biomarkers of inflammation RESULTS: Higher perioperative free Hb levels (and lower haptoglobin levels) were associated with mortality, nosocomial infection, thrombosis, hours of intubation and inotropes, increased interleukin-6, peak serum lactate levels, and lower nadir mean arterial pressures. The median free Hb in patients without infection (30 mg/dL; 29 interquartile range [IQR], 24-52 mg/dL) was lower than in those who became infected (39 mg/dL; IQR, 33-88 mg/ 31 dL; p = 0.0046). The median mechanical ventilation requirements were 19 (IQR, 7-72) hours in patients with higher levels of haptoglobin versus 48 (IQR, 18-144) hours in patients with lower levels (p =â0.0047). Transfusion dose, bypass duration, and complexity of surgery were all significantly correlated with Hb levels and haptoglobin levels. Multivariate analyses demonstrated that these variables were independently and significantly associated with outcomes. CONCLUSIONS: Elevated pre- and postoperative levels of free Hb and decreased levels of haptoglobin were associated with adverse clinical outcomes, inflammation, and unfavorable physiologic metrics. Transfusion, RACHS score, and duration of bypass were associated with increased free Hb and decreased haptoglobin. Further investigation of the role of hemolysis and haptoglobin as potential mediators or markers of outcomes is warranted.
Assuntos
Haptoglobinas/metabolismo , Hemoglobinas/metabolismo , Cirurgia Torácica , Adolescente , Transfusão de Sangue/métodos , Proteína C-Reativa/metabolismo , Ligante de CD40/metabolismo , Criança , Pré-Escolar , Feminino , Hemólise , Humanos , Lactente , Recém-Nascido , Interleucina-6/metabolismo , Masculino , Período Pós-Operatório , Trombose/terapiaRESUMO
Crystalloid infusion is widely employed in patient care for volume replacement and resuscitation. In the United States the crystalloid of choice is often normal saline. Surgeons and anesthesiologists have long preferred buffered solutions such as Ringer's Lactate and Plasma-Lyte A. Normal saline is the solution most widely employed in medical and pediatric care, as well as in hematology and transfusion medicine. However, there is growing concern that normal saline is more toxic than balanced, buffered crystalloids such as Plasma-Lyte and Lactated Ringer's. Normal saline is the only solution recommended for red cell washing, administration and salvage in the USA, but Plasma-Lyte A is also FDA approved for these purposes. Lactated Ringer's has been traditionally avoided in these applications due to concerns over clotting, but existing research suggests this is not likely a problem. In animal models and clinical studies in various settings, normal saline can cause metabolic acidosis, vascular and renal function changes, as well as abdominal pain in comparison with balanced crystalloids. The one extant randomized trial suggests that in very small volumes (2â¯l or less) normal saline is not more toxic than other crystalloids. Recent evidence suggests that normal saline causes substantially more in vitro hemolysis than Plasma-Lyte A and similar solutions during short term storage (24â¯hours) after washing or intraoperative salvage. There are now abundant data to raise concerns as to whether normal saline is the safest replacement solution in infusion therapy, red cell washing and salvage, apheresis and similar uses. In the USA, Plasma-Lyte A is also FDA approved for use with blood components and is likely a safer solution for these purposes. Its only disadvantage is a higher cost. Additional studies of the safety of normal saline for virtually all current clinical uses are needed. It seems likely that normal saline will eventually be abandoned in favor of safer, more physiologic crystalloid solutions in the coming years.
Assuntos
Eletrólitos/efeitos adversos , Eletrólitos/uso terapêutico , Soluções Isotônicas/efeitos adversos , Soluções Isotônicas/uso terapêutico , Cloreto de Sódio/efeitos adversos , Cloreto de Sódio/uso terapêutico , Adolescente , Animais , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Lactato de RingerRESUMO
Stored platelets undergo biochemical, structural and functional changes that lead to decreased efficacy and safety of platelet transfusions. Not only do platelets acquire markers of activation during storage, but they also fail to respond normally to agonists post-storage. We hypothesized that resveratrol, a cardioprotective antioxidant, could act as a novel platelet storage additive to safely prevent unwanted platelet activation during storage, while simultaneously preserving normal haemostatic function. Human platelets treated with resveratrol and stored for 5 d released less thromboxane B2 and prostaglandin E2 compared to control platelets. Resveratrol preserved the ability of platelets to aggregate, spread and respond to thrombin, suggesting an improved ability to activate post-storage. Utilizing an in vitro model of transfusion and thromboelastography, clot strength was improved with resveratrol treatment compared to conventionally stored platelets. The mechanism of resveratrol's beneficial actions on stored platelets was partly mediated through decreased platelet apoptosis in storage, resulting in a longer half-life following transfusion. Lastly, an in vivo mouse model of transfusion demonstrated that stored platelets are prothrombotic and that resveratrol delayed vessel occlusion time to a level similar to transfusion with fresh platelets. We show resveratrol has a dual ability to reduce unwanted platelet activation during storage, while preserving critical haemostatic function.
Assuntos
Plaquetas/efeitos dos fármacos , Preservação de Sangue/métodos , Inibidores da Agregação Plaquetária/farmacologia , Transfusão de Plaquetas/métodos , Estilbenos/farmacologia , Animais , Apoptose/efeitos dos fármacos , Plaquetas/metabolismo , Plaquetas/fisiologia , Inibidores de Ciclo-Oxigenase/farmacologia , Avaliação de Medicamentos/métodos , Hemostasia/efeitos dos fármacos , Humanos , Mediadores da Inflamação/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Ativação Plaquetária/efeitos dos fármacos , Agregação Plaquetária/efeitos dos fármacos , ResveratrolRESUMO
OBJECTIVES: Infants and children undergoing open heart surgery routinely require multiple RBC transfusions. Children receiving greater numbers of RBC transfusions have increased postoperative complications and mortality. Longer RBC storage age is also associated with increased morbidity and mortality in critically ill children. Whether the association of increased transfusions and worse outcomes can be ameliorated by use of fresh RBCs in pediatric cardiac surgery for congenital heart disease is unknown. INTERVENTIONS: One hundred and twenty-eight consecutively transfused children undergoing repair or palliation of congenital heart disease with cardiopulmonary bypass who were participating in a randomized trial of washed versus standard RBC transfusions were evaluated for an association of RBC storage age and clinical outcomes. To avoid confounding with dose of transfusions and timing of infection versus timing of transfusion, a subgroup analysis of patients only transfused 1-2 units on the day of surgery was performed. MEASUREMENTS AND MAIN RESULTS: Mortality was low (4.9%) with no association between RBC storage duration and survival. The postoperative infection rate was significantly higher in children receiving the oldest blood (25-38 d) compared with those receiving the freshest RBCs (7-15 d) (34% vs 7%; p = 0.004). Subgroup analysis of subjects receiving only 1-2 RBC transfusions on the day of surgery (n = 74) also demonstrates a greater prevalence of infections in subjects receiving the oldest RBC units (0/33 [0%] with 7- to 15-day storage; 1/21 [5%] with 16- to 24-day storage; and 4/20 [20%] with 25- to 38-day storage; p = 0.01). In multivariate analysis, RBC storage age and corticosteroid administration were the only predictors of postoperative infection. Washing the oldest RBCs (> 27 d) was associated with a higher infection rate and increased morbidity compared with unwashed RBCs. DISCUSSION: Longer RBC storage duration was associated with increased postoperative nosocomial infections. This association may be secondary in part, to the large doses of stored RBCs transfused, from single-donor units. Washing the oldest RBCs was associated with increased morbidity, possibly from increased destruction of older, more fragile erythrocytes incurred by washing procedures. Additional studies examining the effect of RBC storage age on postoperative infection rate in pediatric cardiac surgery are warranted.
Assuntos
Preservação de Sangue/efeitos adversos , Segurança do Sangue/métodos , Transfusão de Eritrócitos/efeitos adversos , Cardiopatias Congênitas/cirurgia , Cuidados Pós-Operatórios/métodos , Complicações Pós-Operatórias/prevenção & controle , Adolescente , Preservação de Sangue/métodos , Procedimentos Cirúrgicos Cardíacos/efeitos adversos , Procedimentos Cirúrgicos Cardíacos/mortalidade , Ponte Cardiopulmonar/efeitos adversos , Ponte Cardiopulmonar/métodos , Ponte Cardiopulmonar/mortalidade , Criança , Pré-Escolar , Transfusão de Eritrócitos/métodos , Transfusão de Eritrócitos/mortalidade , Feminino , Cardiopatias Congênitas/mortalidade , Mortalidade Hospitalar , Humanos , Lactente , Recém-Nascido , Unidades de Terapia Intensiva , Masculino , Complicações Pós-Operatórias/mortalidade , Complicações Pós-Operatórias/terapia , Fatores de Risco , Análise de Sobrevida , Fatores de Tempo , Resultado do TratamentoRESUMO
Selective glucocorticoid receptor agonists (SEGRAs) are a new class of compounds under clinical evaluation for treatment of ocular inflammation. Widely prescribed therapeutics, such as glucocorticoids, are effective at reducing ocular inflammation, but their long term use predisposes to undesirable side effects. The purpose of this study was to investigate a novel SEGRA, mapracorat (BOL-303242-X), and the differences in mapracorat's mechanism of action compared with traditional steroids (i.e. dexamethasone). Keratocytes from three different humans were cultured and treated with mapracorat or dexamethasone, with and without a strong provoking agent, interleukin (IL)-1ß. The effects of mapracorat compared to dexamethasone were determined by measuring protein levels (Western blotting) and DNA binding (ELISA) for two nuclear factor-kappaB (NF-κB) family members, RelA and RelB. Cytokine production (i.e. IL-6, IL-8, prostaglandin E2 (PGE2)) was characterized by immunoassay. Our findings reveal mechanistic differences between mapracorat and traditional steroid therapies. Mapracorat showed partial attenuation of the classical NF-κB pathway, consistent with traditional steroids. However, mapracorat uniquely potentiated a novel anti-inflammatory mechanism through rapid upregulation of RelB, an anti-inflammatory member of the NF-κB alternative pathway. Mapracorat potently inhibits ocular inflammation in vitro and is a promising new treatment for ocular inflammatory disease. Mapracorat acts, in part, by a novel mechanism via upregulation of RelB in the NF-κB alternative pathway.
Assuntos
Anti-Inflamatórios/farmacologia , Benzofuranos/farmacologia , Ceratócitos da Córnea/efeitos dos fármacos , NF-kappa B/metabolismo , Pentanóis/farmacologia , Quinolinas/farmacologia , Receptores de Glucocorticoides/agonistas , Fator de Transcrição RelB/metabolismo , Western Blotting , Células Cultivadas , Ceratócitos da Córnea/metabolismo , Citocinas/metabolismo , Dexametasona/farmacologia , Ensaio de Imunoadsorção Enzimática , Glucocorticoides/farmacologia , Humanos , Fator de Transcrição RelA/metabolismo , Regulação para CimaRESUMO
BACKGROUND: Stored red blood cells (RBCs) release hemoglobin (Hb) that leads to oxidative damage, which may contribute to thrombosis in susceptible transfusion recipients. Oxidative stress stimulates the generation of a new class of lipid mediators called F2 -isoprostanes (F2 -IsoPs) and isofurans (IsoFs) that influence cellular behavior. This study investigated RBC-derived F2 -IsoPs and IsoFs during storage and their influence on human platelets (PLTs). STUDY DESIGN AND METHODS: F2 -IsoP and IsoF levels in RBC supernatants were measured by mass spectrometry during storage and after washing. The effects of stored supernatants, cell-free Hb, or a key F2 -IsoP, 8-iso-prostaglandin F2α (PGF2α ), on PLT function were examined in vitro. RESULTS: F2 -IsoPs, IsoFs, and Hb accumulated in stored RBC supernatants. Prestorage leukoreduction reduced supernatant F2 -IsoPs and IsoFs levels, which increased again over storage time. Stored RBC supernatants and 8-iso-PGF2α induced PLT activation marker CD62P (P-selectin) expression and prothrombotic thromboxane A2 release. Cell-free Hb did not alter PLT mediator release, but did inhibit PLT spreading. Poststorage RBC washing reduced F2 -IsoP and IsoF levels up to 24 hours. CONCLUSIONS: F2 -IsoPs and IsoFs are produced by stored RBCs and induce adverse effects on PLT function in vitro, supporting a potential novel role for bioactive lipids in adverse transfusion outcomes. F2 -IsoP and IsoF levels could be useful biomarkers for determining the suitability of blood components for transfusion. A novel finding is that cell-free Hb inhibits PLT spreading and could adversely influence wound healing. Poststorage RBC washing minimizes harmful lipid mediators, and its use could potentially reduce transfusion complications.
Assuntos
Plaquetas/metabolismo , Eritrócitos/metabolismo , Furanos/metabolismo , Isoprostanos/metabolismo , Dinoprosta/análogos & derivados , Dinoprosta/metabolismo , F2-Isoprostanos/metabolismo , Humanos , Imunoensaio , Espécies Reativas de Oxigênio/metabolismoRESUMO
Cigarette smoking is a major preventable cause of morbidity and mortality. While quitting smoking is the best option, switching from cigarettes to non-combustible alternatives (NCAs) such as e-vapor products is a viable harm reduction approach for smokers who would otherwise continue to smoke. A key challenge for the clinical assessment of NCAs is that self-reported product use can be unreliable, compromising the proper evaluation of their risk reduction potential. In this cross-sectional study of 205 healthy volunteers, we combined comprehensive exposure characterization with in-depth multi-omics profiling to compare effects across four study groups: cigarette smokers (CS), e-vapor users (EV), former smokers (FS), and never smokers (NS). Multi-omics analyses included metabolomics, transcriptomics, DNA methylomics, proteomics, and lipidomics. Comparison of the molecular effects between CS and NS recapitulated several previous observations, such as increased inflammatory markers in CS. Generally, FS and EV demonstrated intermediate molecular effects between the NS and CS groups. Stratification of the FS and EV by combustion exposure markers suggested that this position on the spectrum between CS and NS was partially driven by non-compliance/dual use. Overall, this study highlights the importance of in-depth exposure characterization before biological effect characterization for any NCA assessment study.
Assuntos
Sistemas Eletrônicos de Liberação de Nicotina , Expossoma , Abandono do Hábito de Fumar , Produtos do Tabaco , Vaping , Humanos , Estudos Transversais , MultiômicaRESUMO
Lung inflammation can result from exposure to multiple types of inflammatory stimuli. Fibroblasts, key structural cells in the lung that are integral to inflammation and wound healing, produce inflammatory mediators after exposure to stimuli such as IL-1ß. We and others have shown that the NF-κB member RelB has anti-inflammatory properties in mice. Little is known, however, about the anti-inflammatory role of RelB in human cells and how it functions. MicroRNAs (miRNAs), a novel class of small, noncoding RNAs, can mediate inflammatory signaling pathways, including NF-κB, through regulation of target gene expression. Our goal was to analyze the anti-inflammatory properties of RelB in human lung fibroblasts. We hypothesized that RelB regulates inflammatory mediator production in lung fibroblasts in part through a mechanism involving miRNAs. To accomplish this, we transfected human lung fibroblasts with a plasmid encoding RelB and small interfering (si)RNA targeting RelB mRNA to overexpress and downregulate RelB, respectively. IL-1ß, a powerful proinflammatory stimulus, was used to induce NF-κB-driven inflammatory responses. RelB overexpression reduced IL-1ß-induced cyclooxygenase (Cox)-2, PGE2, and cytokine production, and RelB downregulation increased Cox-2 expression and PGE2 production. Furthermore, RelB overexpression increased IL-1ß-induced expression of miRNA-146a, an NF-κB-dependent miRNA with anti-inflammatory properties, whereas RelB downregulation reduced miRNA-146a. miR-146a overexpression ablated the effects of RelB downregulation on IL-1ß-induced Cox-2, PGE2, and IL-6 production, suggesting that RelB mediates IL-1ß-induced inflammatory mediator production in lung fibroblasts through miRNA-146a. RelB and miRNA-146a may therefore be new therapeutic targets in the treatment of lung inflammation caused by various agents and conditions.
Assuntos
Mediadores da Inflamação/metabolismo , Pulmão/metabolismo , MicroRNAs/fisiologia , Fator de Transcrição RelB/metabolismo , Ciclo-Oxigenase 2/biossíntese , Dinoprostona/biossíntese , Regulação para Baixo , Fibroblastos/metabolismo , Humanos , Pulmão/efeitos dos fármacos , MicroRNAs/biossíntese , Fator de Transcrição RelB/biossínteseRESUMO
During the last three decades, a growing body of clinical, basic science and animal model data has demonstrated that blood transfusions have important effects on the immune system. These effects include: dysregulation of inflammation and innate immunity leading to susceptibility to microbial infection, down-regulation of cellular (T and NK cell) host defenses against tumors, and enhanced B cell function that leads to alloimmunization to blood group, histocompatibility and other transfused antigens. Furthermore, transfusions alter the balance between hemostasis and thrombosis through inflammation, nitric oxide scavenging, altered rheologic properties of the blood, immune complex formation and, no doubt, several mechanisms not yet elucidated. The net effects are rarely beneficial to patients, unless they are in imminent danger of death due to exsanguination or life threatening anemia. These findings have led to appeals for more conservative transfusion practice, buttressed by randomized trials showing that patients do not benefit from aggressive transfusion practices. At the risk of hyperbole, one might suggest that if the 18th and 19th centuries were characterized by physicians unwittingly harming patients through venesection and bleeding, the 20th century was characterized by physicians unwittingly harming patients through current transfusion practices. In addition to the movement to more parsimonious use of blood transfusions, an effort has been made to reduce the toxic effects of blood transfusions through modifications such as leukoreduction and saline washing. More recently, there is early evidence that reducing the storage period of red cells transfused might be a strategy for minimizing adverse outcomes such as infection, thrombosis, organ failure and mortality in critically ill patients particularly at risk for these hypothesized effects. The present review will focus on two approaches, leukoreduction and saline washing, as means to reduce adverse transfusion outcomes.
Assuntos
Estado Terminal/terapia , Citaferese/estatística & dados numéricos , Sistema Imunitário , Procedimentos de Redução de Leucócitos/estatística & dados numéricos , Reação Transfusional , Bancos de Sangue , Criopreservação , Citaferese/economia , Citaferese/métodos , Humanos , Imunomodulação , Procedimentos de Redução de Leucócitos/economia , Procedimentos de Redução de Leucócitos/métodos , Ensaios Clínicos Controlados Aleatórios como Assunto , Estudos Retrospectivos , Fatores de RiscoRESUMO
BACKGROUND: ABO-mismatched platelets (PLTs) are commonly transfused despite reported complications. We hypothesized that because PLTs possess A and B antigens on their surface, ABO-mismatched transfused or recipient PLTs could become activated and/or dysfunctional after exposure to anti-A or -B in the transfused or recipient plasma. We present here in vitro modeling data on the functional effects of exposure of PLTs to ABO antibodies. STUDY DESIGN AND METHODS: PLT functions of normal PLTs of all ABO types were assessed before and after incubation with normal saline, ABO-identical plasma samples, or O plasma samples with varying titers of anti-A and anti-B (anti-A/B). Assays used for this assessment include PLT aggregation, clot kinetics, thrombin generation, PLT cytoskeletal function, and mediator release. RESULTS: Exposure of antigen-bearing PLTs to O plasma with moderate to high titers of anti-A/B significantly inhibits aggregation, prolongs PFA-100 epinephrine closure time, disrupts clot formation kinetics, accelerates thrombin generation, reduces total thrombin production, alters PLT cytoskeletal function, and influences proinflammatory and prothrombotic mediator release. CONCLUSIONS: Our findings demonstrate a wide range of effects that anti-A/B have on PLT function, clot formation, thrombin generation, PLT cytoskeletal function, and mediator release. These data provide potential explanations for clinical observations of increased red blood cell utilization in trauma and surgical patients receiving ABO-nonidentical blood products. Impaired hemostasis caused by anti-A/B interacting with A and B antigens on PLTs, soluble proteins, and perhaps even endothelial cells is a potential contributing factor to hemorrhage in patients receiving larger volumes of ABO-nonidentical transfusions.
Assuntos
Sistema ABO de Grupos Sanguíneos/imunologia , Anticorpos/farmacologia , Coagulação Sanguínea/efeitos dos fármacos , Plaquetas/efeitos dos fármacos , Plaquetas/fisiologia , Adulto , Coagulação Sanguínea/fisiologia , Tipagem e Reações Cruzadas Sanguíneas , Plaquetas/imunologia , Feminino , Humanos , Técnicas In Vitro , Cinética , Masculino , Pessoa de Meia-Idade , Agregação Plaquetária/efeitos dos fármacos , Agregação Plaquetária/fisiologia , Fatores de Tempo , TitulometriaRESUMO
CD40L is a type II membrane glycoprotein of the TNF family that is found on activated T cells, B cells, and platelets. We previously reported that the soluble form of this inflammatory mediator (sCD40L) is elevated in the plasma and cerebrospinal fluid of HIV-1-infected, cognitively impaired individuals. In this study, we demonstrate that the mood-stabilizing drug valproic acid (VPA) reduces sCD40L levels in plasma samples of HIV-1-infected patients (n = 23) and in washed human platelets, which are the main source of circulating sCD40L. VPA also inhibited HIV-1 transactivator of transcription-induced release of sCD40L and platelet factor 4 in C57BL/6 mice. The mechanism by which VPA was able to do so was investigated, and we demonstrate that VPA, a known glycogen synthase kinase 3ß inhibitor, blocks platelet activating factor-induced activation of glycogen synthase kinase 3ß in platelets in a manner that alters sCD40L release from platelets. These data reveal that VPA has antiplatelet activity, and they convey important implications for the potential of VPA as an adjunct therapy not only for cognitively impaired patients with HIV-1 infection, but also numerous inflammatory diseases for which such antiplatelet therapies are currently lacking.
Assuntos
Plaquetas/imunologia , Ligante de CD40/antagonistas & inibidores , Ligante de CD40/biossíntese , Regulação para Baixo/imunologia , Infecções por HIV/imunologia , HIV-1/imunologia , Inibidores da Agregação Plaquetária/farmacologia , Ácido Valproico/farmacologia , Complexo AIDS Demência/sangue , Complexo AIDS Demência/imunologia , Complexo AIDS Demência/terapia , Animais , Plaquetas/efeitos dos fármacos , Plaquetas/enzimologia , Ligante de CD40/sangue , Regulação para Baixo/efeitos dos fármacos , Feminino , Quinase 3 da Glicogênio Sintase/antagonistas & inibidores , Quinase 3 da Glicogênio Sintase/biossíntese , Quinase 3 da Glicogênio Sintase/sangue , Glicogênio Sintase Quinase 3 beta , Infecções por HIV/sangue , Infecções por HIV/terapia , HIV-1/efeitos dos fármacos , Humanos , Mediadores da Inflamação/sangue , Mediadores da Inflamação/fisiologia , Mediadores da Inflamação/uso terapêutico , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Projetos Piloto , Inibidores da Agregação Plaquetária/sangue , Inibidores da Agregação Plaquetária/uso terapêutico , Solubilidade , Ácido Valproico/sangue , Ácido Valproico/uso terapêuticoRESUMO
OBJECTIVES: Children undergoing cardiac surgery with cardiopulmonary bypass are susceptible to additional inflammatory and immunogenic insults from blood transfusions. We hypothesize that washing red blood cells and platelets transfused to these patients will reduce postoperative transfusion-related immune modulation and inflammation. DESIGN: Prospective, randomized, controlled clinical trial. SETTING: University hospital pediatric cardiac intensive care unit. PATIENTS: Children from birth to 17 yrs undergoing cardiac surgery with cardiopulmonary bypass. INTERVENTIONS: Children were randomized to an unwashed or washed red blood cells and platelet transfusion protocol for their surgery and postoperative care. All blood was leuko-reduced, irradiated, and ABO identical. Plasma was obtained for laboratory analysis preoperatively, immediately, and 6 and 12 hrs after cardiopulmonary bypass. Primary outcome was the 12-hr postcardiopulmonary bypass interleukin-6-to-interleukin-10 ratio. Secondary measures were interleukin levels, C-reactive protein, and clinical outcomes. MEASUREMENTS AND MAIN RESULTS: One hundred sixty-two subjects were studied, 81 per group. Thirty-four subjects (17 per group) did not receive any blood transfusions. Storage duration of blood products was similar between groups. Among transfused subjects, the 12-hr interleukin ratio was significantly lower in the washed group (3.8 vs. 4.8; p = .04) secondary to lower interleukin-6 levels (after cardiopulmonary bypass: 65 vs.100 pg/mL, p = .06; 6 hrs: 89 vs.152 pg/mL, p = .02; 12 hrs: 84 vs.122 pg/mL, p = .09). Postoperative C-reactive protein was lower in subjects receiving washed blood (38 vs. 43 mg/L; p = .03). There was a numerical, but not statistically significant, decrease in total blood product transfusions (203 vs. 260) and mortality (2 vs. 6 deaths) in the washed group compared to the unwashed group. CONCLUSIONS: Washed blood transfusions in cardiac surgery reduced inflammatory biomarkers, number of transfusions, donor exposures, and were associated with a nonsignificant trend toward reduced mortality. A larger study powered to test for clinical outcomes is needed to determine whether these laboratory findings are clinically significant.
Assuntos
Coleta de Amostras Sanguíneas/métodos , Procedimentos Cirúrgicos Cardíacos , Ponte Cardiopulmonar , Transfusão de Eritrócitos/métodos , Inflamação/prevenção & controle , Transfusão de Plaquetas/métodos , Complicações Pós-Operatórias/prevenção & controle , Adolescente , Biomarcadores/sangue , Perda Sanguínea Cirúrgica , Proteína C-Reativa/metabolismo , Procedimentos Cirúrgicos Cardíacos/mortalidade , Ponte Cardiopulmonar/mortalidade , Criança , Pré-Escolar , Transfusão de Eritrócitos/estatística & dados numéricos , Feminino , Humanos , Lactente , Recém-Nascido , Inflamação/sangue , Inflamação/etiologia , Interleucina-10/sangue , Interleucina-6/sangue , Masculino , Transfusão de Plaquetas/estatística & dados numéricos , Cuidados Pós-Operatórios/métodos , Complicações Pós-Operatórias/sangue , Estudos Prospectivos , Resultado do TratamentoRESUMO
Red blood cell (RBC) transfusions are associated with inflammation and thrombosis, both arterial and venous, the mechanisms of which are not understood. Although a necessary life-saving procedure in modern medicine, transfusions have rarely been subjected to modern assessments of efficacy and safety, including randomized trials. Storage of RBCs induces changes, including the release of free hemoglobin and the accumulation of biologically active soluble mediators and microparticles. These mediators likely play a direct role in the inflammatory and prothrombotic properties of RBC transfusions. Methods such as leukoreduction, washing of RBCs, and rejuvenation may improve the quality of RBC transfusions.
Assuntos
Preservação de Sangue/efeitos adversos , Transfusão de Eritrócitos/efeitos adversos , Transfusão de Eritrócitos/métodos , Plaquetas/citologia , Plaquetas/metabolismo , Eritrócitos/citologia , Eritrócitos/metabolismo , HumanosRESUMO
BACKGROUND: Transfusion of ABO non-identical plasma, platelets and cryoprecipitate is routine practice even though adverse effects can occur. METHODS AND MATERIALS: Our hospital changed transfusion practice in 2005 and adopted a policy of providing ABO-identical blood components to all patients when feasible. We retrospectively compared the transfusion requirements, length of stay and in-hospital mortality in relation to ABO blood group in surgical patients who received platelet transfusions before and after this change to determine whether it resulted in any benefit. RESULTS: Prior to the change in practice, both group B and AB patients received more ABO non-identical platelet transfusion (P=0·0004), required significantly greater numbers of red cell transfusions (P=0·04) and had 50% longer hospital stays (P=0·039) than group O and A patients. Following the policy change, there was a trend for fewer red cell transfusions (P=0·17) and length of stay in group B and AB patients than group O or A patients. Overall, the mortality rate per red cell transfusion decreased from 15·2 per 1000 to 11·0 per 1000 (P=0·013). CONCLUSIONS: These results, in the context of previous findings, suggest that providing ABO-identical platelets and cryoprecipitate might be associated with reduction in transfusion requirements and improve outcomes in surgical patients.
Assuntos
Sistema ABO de Grupos Sanguíneos/imunologia , Tipagem e Reações Cruzadas Sanguíneas/estatística & dados numéricos , Transfusão de Eritrócitos/estatística & dados numéricos , Mortalidade Hospitalar , Tempo de Internação/estatística & dados numéricos , Transfusão de Plaquetas/estatística & dados numéricos , Hemorragia Pós-Operatória/terapia , Adulto , Idoso , Transfusão de Componentes Sanguíneos/estatística & dados numéricos , Incompatibilidade de Grupos Sanguíneos/epidemiologia , Tipagem e Reações Cruzadas Sanguíneas/métodos , Transfusão de Eritrócitos/efeitos adversos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Plasma/imunologia , Transfusão de Plaquetas/efeitos adversos , Estudos RetrospectivosRESUMO
OBJECTIVE: To investigate the presence and role of NF-kappaB proteins in megakaryocytes and platelets. The nuclear factor-kappaB (NF-kappaB) transcription factor family is well known for its role in eliciting inflammation and promoting cell survival. We discovered that human megakaryocytes and platelets express the majority of NF-kappaB family members, including the regulatory inhibitor-kappaB (I-kappaB) and I-kappa kinase (IKK) molecules. METHODS AND RESULTS: Anucleate platelets exposed to NF-kappaB inhibitors demonstrated impaired fundamental functions involved in repairing vascular injury and thrombus formation. Specifically, NF-kappaB inhibition diminished lamellapodia formation, decreased clot retraction times, and reduced thrombus stability. Moreover, inhibition of I-kappaB-alpha phosphorylation (BAY-11-7082) reverted fully spread platelets back to a spheroid morphology. Addition of recombinant IKK-beta or I-kappaB-alpha protein to BAY inhibitor-treated platelets partially restored platelet spreading in I-kappaB-alpha inhibited platelets, and addition of active IKK-beta increased endogenous I-kappaB-alpha phosphorylation levels. CONCLUSIONS: These novel findings support a crucial and nonclassical role for the NF-kappaB family in modulating platelet function and reveal that platelets are sensitive to NF-kappaB inhibitors. As NF-kappaB inhibitors are being developed as antiinflammatory and anticancer agents, they may have unintended effects on platelets. On the basis of these data, NF-kappaB is also identified as a new target to dampen unwanted platelet activation.
Assuntos
Plaquetas/metabolismo , Megacariócitos/metabolismo , NF-kappa B/metabolismo , Adulto , Idoso , Plaquetas/efeitos dos fármacos , Plaquetas/patologia , Adesão Celular/efeitos dos fármacos , Diferenciação Celular , Linhagem Celular Tumoral , Forma Celular/efeitos dos fármacos , Feminino , Sangue Fetal/citologia , Sangue Fetal/metabolismo , Humanos , Leucemia Megacarioblástica Aguda/metabolismo , Leucemia Megacarioblástica Aguda/patologia , Masculino , Megacariócitos/efeitos dos fármacos , Megacariócitos/patologia , Pessoa de Meia-Idade , NF-kappa B/antagonistas & inibidores , Subunidade p50 de NF-kappa B/metabolismo , Nitrilas/farmacologia , Sulfonas/farmacologia , Fator de Transcrição RelA/metabolismoRESUMO
Platelet transfusion has long been practiced with rudimentary knowledge about optimal storage conditions and their implications for efficacy and, particularly, safety. Recent concerns about complications such as inflammation, thrombosis and altered recipient immunity have been raised about platelet transfusion. This review will discuss recent important findings that have raised these issues about platelet transfusion associated morbidity, mortality and the possible role of platelet storage in these associations.