Search

Idiopathic thrombocytopenic purpura in children usually a self limiting disorder. It may follow a viral infection or immunisation and is caused by an inappropriate response of the immune system. About 20-30% of children will fail to remit over six months (chronic idiopathic thrombocytopenic purpura). This is more likely in older children, especially girls. The disease is reviewed with reference to diagnosis, investigation, and management options. [ABSTRACT FROM AUTHOR]

Guidelines for the prevention and treatment of infection in patients with an absent or dysfunctional spleen were published by the British Committee for Standards in Haematology in 1996 and updated in 2002 and 2011. With advances in vaccinations and changes in patterns of infection, the guidelines required updating. Key aspects included in this guideline are the identification of patients at risk of infection, patient education and information and immunisation schedules. This guideline does not address the non-infective complications of splenectomy or functional hyposplenism (FH). This replaces previous guidelines and significantly revises the recommendations related to immunisation. Patients at risk include those who have undergone surgical removal of the spleen, including partial splenectomy and splenic embolisation, and those with medical conditions that predispose to FH. Immunisations should include those against Streptococcus pneumoniae (pneumococcus), Neisseria meningitidis (meningococcus) and influenza. Haemophilus influenzae type b (Hib) is part of the infant immunisation schedule and is no longer required for older hyposplenic patients. Treatment of suspected or proven infections should be based on local protocols and consider relevant anti-microbial resistance patterns. The education of patients and their medical practitioners is essential, particularly in relation to the risk of serious infection and its prevention. Further research is required to establish the effectiveness of vaccinations in hyposplenic patients; infective episodes should be regularly audited. There is no single group ideally placed to conduct audits into complications arising from hyposplenism, highlighting a need for a national registry, as has proved very successful in Australia or alternatively, the establishment of appropriate multidisciplinary networks., (© 2024 British Society for Haematology and John Wiley & Sons Ltd.)

Background: Factor (F) XI deficiency is associated with increased bleeding risk in some individuals. Neither FXI levels nor clinical clotting assays predict the bleeding risk. Compared with controls, FXI-deficient bleeders have reduced clot formation, decreased fibrin network density, and increased susceptibility to fibrinolysis. Tissue factor pathway inhibitor (TFPI) was recently implicated as a modifying factor in individuals with bleeding of unknown cause., Objectives: To determine the potential of TFPI in modifying the bleeding risk in FXI-deficient individuals., Methods: The effects of TFPI on thrombin generation and clot formation, structure, and fibrinolysis in FXI-deficient plasma were measured in vitro in the absence or presence of inhibitory anti-TFPI antibody or exogenous recombinant TFPIα. Total plasma TFPI concentration was measured in 2 independent cohorts of controls and FXI-deficient individuals classified as bleeders or nonbleeders (cohort 1: 10 controls and 16 FXI-deficient individuals; cohort 2: 48 controls and 57 FXI-deficient individuals) and correlated with ex vivo plasma clot formation and fibrinolysis parameters associated with bleeding risk., Results: In an in vitro FXI deficiency model, inhibition of TFPI enhanced thrombin generation and clot formation, increased the network density, and decreased fibrinolysis, whereas an increase in TFPI had the opposite effects. Compared with controls, plasma from FXI-deficient bleeders had higher TFPI concentration. Total plasma TFPI concentrations correlated with parameters from ex vivo clotting and fibrinolysis assays that differentiate FXI-deficient bleeders and nonbleeders., Conclusion: Coagulation and fibrinolysis parameters that differentiate FXI-deficient nonbleeders and bleeders were altered by plasma TFPIα. Total plasma TFPI was increased in FXI-deficient bleeders. TFPI may modify the bleeding risk in FXI-deficient individuals., Competing Interests: Declaration of competing interest A.E.M. receives research funding and honoraria from Novo Nordisk. No other authors have relevant competing interests to disclose., (Copyright © 2022 International Society on Thrombosis and Haemostasis. Published by Elsevier Inc. All rights reserved.)

Background: Irradiation of cellular blood components is recommended for patients at risk of transfusion-associated graft-vs-host disease (TA-GvHD). Prestorage leucodepletion (LD) of blood components is standard in the UK since 1999., Study Design and Methods: Analysis of 10 years' reports from UK national hemovigilance scheme, Serious Hazards of Transfusion (2010-2019), where patients failed to receive irradiated components when indicated according to British Society for Haematology guidelines (2011)., Results: There were 956 incidents of failure to receive irradiated components all due to errors. One hundred and seventy two incidents were excluded from analysis, 125 of 172 (72.7%) because of missing essential information. No cases of TA-GvHD were reported in this cohort. The 784 patients received 2809 components (number unknown for 67 incidents). Most failures occurred in patients treated with purine analogues (365) or alemtuzumab (69), or with a history of Hodgkin lymphoma (HL) (192). Together these make up 626 of 784 (79.9%). Poor communication is an important cause of errors., Conclusion: Leucodepletion appears to reduce the risk for TA-GvHD. None of 12 cases of TA-GvHD reported to SHOT prior to introduction of LD occurred in patients with conditions recommended for irradiated components by current guidelines. Irradiation indefinitely for all stages of HL is not based on good evidence and is a difficult guideline to follow. Further research on long-term immune function in HL is required. Variation between different national guidelines reflects the very limited evidence., (© 2020 The Authors. Transfusion published by Wiley Periodicals LLC. on behalf of AABB.)

Introduction: The World Federation of Hemophilia (WFH) strives to achieve care for all patients with inherited bleeding disorders through research, advocacy, capacity building and education. The WFH developed and implemented the Annual Global Survey (AGS), through which comprehensive demographic and treatment data on bleeding disorders are collected each year from its constituent non-governmental national organizations., Aim: To describe the development, methodology and achievements of the WFH AGS over the past 20 years., Methods: The AGS is a yearly cross-sectional survey. Data are collected using a standardized form (available online and on paper), quality checked and reviewed, and published in English, French and Spanish. Over time, the AGS has been modified in response to changes in treatment landscape or emerging new issues., Results: Over the past 20 years, the AGS has reported an increase in the number of countries participating in the survey, a tripling in the number of people identified with rare bleeding disorders and an increase in the amount of factor used to treat people with haemophilia. Yet, a large treatment inequity gap still exists across the globe. In response to this gap, the WFH has analysed the AGS reports which has stimulated further development in quality of care indicators, estimates of the global prevalence of haemophilia, patient-level data collection efforts like the World Bleeding Disorders Registry and the Gene Therapy Registry., Conclusion: The AGS has provided evidence to support research, programme planning and development activities of the WFH., (© 2020 John Wiley & Sons Ltd.)

The Annual SHOT Report was published on July 12 at the Annual Symposium. This was preceded by a 2-day meeting of the International Haemovigilance Network (IHN). The IHN meeting provides an opportunity for haemovigilance experts to network with one another and share presentations, which this year included those from China and Taiwan. Reviews of pulmonary complications were highlighted since the definitions of both transfusion-related acute lung injury and transfusion-associated circulatory overload are undergoing revision. The seminar provided an opportunity to present some UK data to an international group (the INTERVAL donor study, the value of big data and work on genomics and human factors). SHOT reports for incidents reported in 2017 demonstrate that, overall, 85·5% are caused by errors. Key recommendations from SHOT are: (i) All staff involved in transfusion must be trained in and know ABO group compatibility. Clinical staff must not just rely on the laboratory staff to get this right. (ii) IT systems have the potential to increase transfusion safety by minimising human factors and should be considered for all transfusion steps. (iii) A formal risk assessment for transfusion-associated circulatory overload should be undertaken wherever possible., (© 2018 British Blood Transfusion Society.)

Aims/objectives: To review if ABO/D grouping errors are more likely to occur with manual intervention compared to automation., Background: Human errors in manual pre-transfusion testing may result in ABO/D-incompatible transfusions and catastrophic outcomes. Accurate ABO/D grouping is a critical part of pre-transfusion testing., Methods: This was a retrospective analysis of reports made to Serious Hazards of Transfusion (SHOT) between January 2004 and December 2016 where ABO/D grouping errors led to the transfusion of an incorrect blood component to review if errors are more likely to occur with manual intervention compared to automation., Results: In 148 of 158 (93%) ABO/D grouping errors, manual intervention took place. In the remaining 10, causes were not reported. No errors occurred with full automation. Interpretation errors occurred in 86 of 148 (58%) and 42 of 148 (28%) transcription errors, and in 20 of 148, wrong or no samples were selected. Of 148 errors, 21 (14%) resulted in ABO-incompatible transfusion, with one death in 2004 due to an interpretation error in a manual ABO group. In 30 of 148 (20%), D-positive red cells were given to D-negative recipients, where three women of child-bearing potential became sensitised and developed anti-D. ABO grouping errors have reduced from 18 of 539 (3%) of total reports analysed in 2004 (3·3%) to 3 of 3091 (0·10%) in 2016., Conclusions: Where manual testing cannot be avoided, results should be confirmed using automated techniques as soon as possible, and a back-up process should be available 24/7. SHOT data confirm that manual interventions are prone to human error, especially in transcription and interpretation, and demonstrate a continuing need for appropriate serological knowledge and understanding by transfusion laboratory staff to underpin safety provided by automation and information technology (IT)., (© 2019 British Blood Transfusion Society.)

Individuals with factor XI (FXI) deficiency have a variable bleeding risk that cannot be predicted from plasma FXI antigen or activity. This limitation can result in under- or overtreatment of patients and risk of bleeding or thrombosis. Previously, plasma clot fibrinolysis assays showed sensitivity to bleeding tendency in a small cohort of patients with severe FXI deficiency. Here, we determined the ability of plasma clot formation, structure, and fibrinolysis assays to predict bleeding tendency in a larger, independent cohort of patients with severe and partial FXI deficiency. Patients were characterized as nonbleeders or bleeders based on bleeding after tonsillectomy and/or dental extraction before diagnosis of FXI deficiency. Blood was collected in the absence or presence of the contact pathway inhibitor corn trypsin inhibitor (CTI). Clotting was triggered in platelet-poor plasma with tissue factor, CaCl 2 , and phospholipids in the absence and presence of thrombomodulin or tissue plasminogen activator. Clot formation and fibrinolysis were assessed by turbidity and confocal microscopy. CTI-treated plasmas from bleeders showed significantly reduced clot formation and decreased resistance to fibrinolysis compared with plasmas from controls or nonbleeders. Differences were enhanced in the presence of CTI. A model that combines activated partial thromboplastin time with the rate of clot formation and area under the curve in fibrinolysis assays identifies most FXI-deficient bleeders. These results show assays with CTI-treated platelet-poor plasma reveal clotting and clot stability deficiencies that are highly associated with bleeding tendency. Turbidity-based fibrinolysis assays may have clinical utility for predicting bleeding risk in patients with severe or partial FXI deficiency., (© 2018 by The American Society of Hematology.)

The Annual SHOT Report for incidents in 2016 was published on July 12 and celebrated of 20 years of UK haemovigilance. Components are very safe, related in part to risk-reduction measures triggered by SHOT reporting. Transfusion-related acute lung injury is now very rare (all plasma components are provided from male donors), and infection transmission is also uncommon - a single transmission of hepatitis E in 2016 and no bacterial transmissions. Human factors (errors) account for 87% of all reports. Deaths and major morbidity most often result from transfusion-associated circulatory overload. Wrong transfusions and deaths from ABO-incompatible transfusion can be reduced by correct bedside checks. It is notable that information technology systems may not be safe. Standardisation is required for flags and alerts. SHOT key recommendations include: assess patients for transfusion-associated circulatory overload prior to transfusion. Be like a pilot - use a bedside checklist when setting up the transfusion., (© 2017 British Blood Transfusion Society.)

Introduction: The absence of a reliable clinical test to predict bleeding tendency leaves factor XI (FXI)-deficient individuals at risk of overtreatment or under treatment., Aim: To assess whether rotational thromboelastometry has value in detection of FXI deficiency and identification of bleeding tendency., Methods: Thromboelastometry was measured in whole blood and platelet-rich plasma (PRP) samples containing corn trypsin inhibitor (CTI) from controls (n = 50) and FXI-deficient individuals (n = 93) at tissue factor (TF) 0.12 pm. The effect of tissue plasminogen activator was also assessed. For analysis, FXI-deficient individuals were divided into bleeders (n = 24) and non-bleeders (n = 44) based on experience of tonsillectomy and/or dental extraction prior to diagnosis., Results: In whole blood, thromboelastometry distinguished those with major FXI deficiency (FXI:C ≤ 15 IU dL -1 ) but not partial deficiency from control populations, but did not identify bleeding phenotype. In PRP, bleeders had significantly longer clot formation time [CFT; 434 ± 179 s vs. 277 ± 70 s (mean ± SD); P < 0.05] and smaller α angle [43.8 ± 9.5° vs. 52.4 ± 5.8° (mean ± SD); P < 0.05] compared to non-bleeders. However, these parameters were found to depend on multiple additional variables and on an individual basis, ROC analysis showed test specificity for bleeding phenotype identification to be only 38.5% at 100% sensitivity: CFT (area under first derivative curve: AUC = 0.8091, P = 0.0014), α angle (AUC = 0.7804, P = 0.006)., Conclusion: Thromboelastometry in PRP with CTI samples triggered with TF 0.12 pm was able to distinguish between bleeders and non-bleeders in FXI deficiency, but poor specificity restricts its clinical application as a test to identify bleeding phenotype. Further technical advances to the assay may allow better discrimination., (© 2017 John Wiley & Sons Ltd.)

Recurrent gastrointestinal bleeding is one of the most challenging complications encountered in the management of patients with von Willebrand disease (VWD). The commonest cause is angiodysplasia, but often no cause is identified due to the difficulty in making the diagnosis. The optimal treatment to prevent recurrences remains unknown. We performed a retrospective study of VWD patients with occult or angiodysplastic bleeding within the setting of the von Willebrand Disease Prophylaxis Network (VWD PN) to describe diagnostic and treatment strategies. Centres participating in the VWD PN recruited subjects under their care with a history of congenital VWD and gastrointestinal (GI) bleeding due to angiodysplasia, or cases in which the cause was not identified despite investigation. Patients with acquired von Willebrand syndrome or those for whom the GI bleeding was due to another cause were excluded. Forty-eight patients from 18 centres in 10 countries were recruited. Seven individuals had a family history of GI bleeding and all VWD types except 2N were represented. Angiodysplasia was confirmed in 38%, with video capsule endoscopy and GI tract endoscopies being the most common methods of making the diagnosis. Recurrent GI bleeding in VWD is associated with significant morbidity and required hospital admission on up to 30 occasions. Patients were treated with multiple pharmacological agents with prophylactic von Willebrand factor concentrate being the most efficient in preventing recurrence of the GI bleeding. The diagnosis and treatment of recurrent GI bleeding in congenital VWD remains challenging and is associated with significant morbidity. Prophylactic treatment with von Willebrand factor concentrate was the most effective method of preventing recurrent bleeding but its efficacy remains to be confirmed in a prospective study., (© 2014 John Wiley & Sons Ltd.)