Outcome evaluation of the p drivers Program: Randomised controlled trial of a program to improve safe driving among novice drivers

BACKGROUND

Globally, road traffic crashes are the leading cause of death for young adults. The P Drivers Project was a trial of a behavioural change program developed for, and targeted at, young Australian drivers in their initial months of solo driving when crash risk is at its highest.

METHODS

In a parallel group randomised controlled trial, drivers (N = 35,109) were recruited within 100 days of obtaining their probationary licence (allowing them to drive unaccompanied) and randomised to an intervention or control group. The intervention was a 3 to 6-week multi-stage driving behaviour change program (P Drivers Program). Surveys were administered at three time points (pre-Program, approximately one month post-Program and at 12 months after). The outcome evaluation employed an on-treatment analysis comprising the 2,419 intervention and 2,810 control participants who completed all required activities, comparing self-reported crashes and police-reported casualty crashes (primary outcome), infringements, self-reported attitudes and behaviours (secondary outcomes) between groups.

RESULTS

The P Drivers Program improved awareness of crash risk factors and intentions to drive more safely, relative to the controls; effects were maintained after 12-months. However, the Program did not reduce self-reported crashes or police-reported casualty crashes. In addition, self-reported violations, errors and risky driving behaviours increased in the intervention group compared to the control group as did recorded traffic infringements. This suggests that despite the Program increasing awareness of risky behaviour in novice drivers, behaviour did not improve. This reinforces the need to collect objective measures to accompany self-reported behaviour and intentions.

CONCLUSIONS

The P Drivers Program was successful in improving attitudes toward driving safety but the negative impact on behaviour, lack of effect on crashes, and the large loss to follow-up fail to support the use of a post-licensing behaviour change program to improve novice driver behaviour and reduce crashes.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry: 363,293 (ANZCTR, 2012).

A British Society for Haematology Guideline: Diagnosis and management of thrombotic thrombocytopenic purpura and thrombotic microangiopathies

The objective of this guideline is to provide healthcare professionals with clear, up-to-date and practical guidance on the management of thrombotic thrombocytopenic purpura (TTP) and related thrombotic microangiopathies (TMAs), including complement-mediated haemolytic uraemic syndrome (CM HUS); these are defined by thrombocytopenia, microangiopathic haemolytic anaemia (MAHA) and small vessel thrombosis. Within England, all TTP cases should be managed within designated regional centres as per NHSE commissioning for highly specialised services.

Social comparisons on social media: online appearance-related activity and body dissatisfaction in adolescent girls

INTRODUCTION

Adolescents' engagement with online social networking platforms is advancing at an exponential rate and research is needed to investigate any impact on young users' mental health. This study examined appearance-related activity (e.g. looking at photos of friends) on social media and body dissatisfaction among adolescent girls.

METHODS

Self-report measures of online appearance-related activity, social comparisons to female target groups, internalization of the thin ideal, body dissatisfaction, and self-esteem were administered to 210 girls (mean age = 15.16 years).

RESULTS

Body dissatisfaction was significantly related to (i) time spent engaged in social comparisons and (ii) upward social comparisons with various female targets while online. Evaluating oneself less favorably than the target group of close friends was most strongly associated with poorer body image appraisals. Serial multiple mediation analysis revealed that even after controlling for age and self-esteem, time spent engaged in social comparisons significantly mediated the relationship between online appearance-related activity and body dissatisfaction. This association was then further partially mediated by internalization of the thin ideal, which significantly mediated the relationship between time engaged in social comparisons and body dissatisfaction.

DISCUSSION

Results are discussed in terms of online social media platforms representing an additional appearance culture environment for adolescent girls. The effects of this on the mental health of vulnerable users and how future research should investigate protective factors that may buffer young girls from the adverse effects of social media are considered.

The largest prison outbreak of TB in Western Europe investigated using whole-genome sequencing

BACKGROUND: In March 2011, the Department of Public Health East in Ireland were notified of two cases of TB in two prisoners sharing a cell. We define the resulting outbreak and highlight the role of public health and laboratory-based molecular epidemiology in mapping and control of a prison outbreak.METHODS: Cases were identified through clinical presentation, contact tracing, case-finding exercise or enhanced laboratory surveillance. Mycobacterium tuberculosis isolates were genotyped and underwent whole-genome sequencing (WGS).RESULTS: Of the 34 cases of TB linked to the outbreak, 27 were prisoners (79%), 4 prison officers (12%) and 3 community cases (9%). M. tuberculosis was isolated from 31 cases (culture positivity: 91%). A maximum of six single-nucleotide polymorphisms separated the isolates, with 22 being identical, suggestive of a highly infectious 'super-spreader´ within the prison. Isolates belonged to the Beijing sub-lineage, and were susceptible to first-line anti-TB agents. A case-finding exercise incidentally detected a prisoner with multidrug-resistant TB. Of the 143 prison officers screened, 52% had latent TB infection. Litigation costs exceeded five million euros.CONCLUSION: This constitutes the largest prison outbreak of TB in Western Europe investigated using WGS. A robust prison entry TB screening and education programme is required to effect better TB control, and prevent future outbreaks and attendant litigation.

Laboratory biomarkers associated with COVID-19 severity and management

The heterogeneous disease course of COVID-19 is unpredictable, ranging from mild self-limiting symptoms to cytokine storms, acute respiratory distress syndrome (ARDS), multi-organ failure and death. Identification of high-risk cases will enable appropriate intervention and escalation. This study investigates the routine laboratory tests and cytokines implicated in COVID-19 for their potential application as biomarkers of disease severity, respiratory failure and need of higher-level care.

From analysis of 203 samples, CRP, IL-6, IL-10 and LDH were most strongly correlated with the WHO ordinal scale of illness severity, the fraction of inspired oxygen delivery, radiological evidence of ARDS and level of respiratory support (p ≤ 0.001). IL-6 levels of ≥3.27 pg/ml provide a sensitivity of 0.87 and specificity of 0.64 for a requirement of ventilation, and a CRP of ≥37 mg/l of 0.91 and 0.66.

Reliable stratification of high-risk cases has significant implications on patient triage, resource management and potentially the initiation of novel therapies in severe patients.

Using technology and cross-cultural teams to deliver trauma-informed medication management

Issue/Problem

Cambodian Americans have high rates of mental health conditions, diabetes and cardiovascular disease. Unique risk factors include history of malnutrition, torture, social isolation, and poor social determinants of health. Community CARES is a trauma-informed model applicable to any trauma community with complex chronic health and mental health problems.

Description of the problem

High-touch, high-tech approaches can improve access to culturally and linguistically appropriate medication therapy management (MTM) services. Over 12 months, pharmacists teamed with community health workers (CHWs) to provide MTM services in Connecticut and California. Face-to-face consultations occurred in Connecticut, while patients and CHWs in California used teleconferencing with the pharmacist in Connecticut. Project goals: improve drug therapy outcomes, reduce inappropriate medication use, improve medication adherence, display cost savings.

Results

96 patients, average age 69, completed the project. Patients averaged 6.6 medical conditions and 10.3 medications. Pharmacists identified 604 medication-related problems, resolving 93%. Drug therapy outcomes increased 35%, medication adherence improved 23%, inappropriate medication use decreased 35%, and depression screening scores improved 25%. Return on investment ratio was 6:1, a savings of $3032/patient/year. Health improvements from face-to-face and telehealth MTM consultations were similar.

Lessons

Healthcare workforce is optimized by linking CHWs with pharmacists and technology to deliver cost-effective MTM services. The approach is generalizable to populations challenged by distance, disability, language, or culture. Public health care policies need to reflect team approaches and value-based payment models.

Main messages: The virtual cross-cultural team MTM model for underserved populations has the potential to meet the triple aim goals of better care, better health, and lower costs in multiple settings.

Key messages

Virtual cross-cultural team MTM model for underserved populations. Meets the triple aim goals of better care, better health, and lower costs in multiple settings.

Pharmacokinetics of plasma infusion in congenital thrombotic thrombocytopenic purpura

Essentials Congenital thrombotic thrombocytopenic purpura (TTP) is primarily treated with plasma infusion. We present a pharmacokinetic analysis of ADAMTS-13 in six patients following plasma infusion. A median half-life of 130 h was demonstrated, ranging between 82.6 and 189.5 h. Investigation of interindividual clearance of ADAMTS-13 is necessary to optimize treatment. SUMMARY: Background Congenital thrombotic thrombocytopenic purpura (TTP) is defined by persistent severe deficiency of ADAMTS-13 in the absence of anti-ADAMTS-13 inhibitory antibodies, confirmed by mutational analysis. Replacement of the missing protease prevents disease relapse, primarily using plasma infusion (PI). Objectives, patients and methods There is scant evidence regarding optimal dose and frequency of treatment, which tends to be empirically guided. We present a pharmacokinetic analysis of ADAMTS-13 in six patients with congenital TTP on established regimes following PI. Results We found a median clearance of 25.41 mL h-1 and half-life of 130 h, ranging between 82.6 and 189.5 h (3.4-7.9 days, respectively). All patients reached baseline ADAMTS-13 level within 7-10 days post-plasma. Median ADAMTS-13 activity peak post-PI was 24.05 IU dL-1 . Variation was related to elimination rate, which, in turn, was affected by weight and metabolism, but not to von Willebrand factor antigen or activity levels. Using the pharmacokinetic parameters, we simulated individualized protocols based on PI dose or frequency to target hypothetical optimal plasma levels of ADAMTS-13 of 10 and 50 IU dL-1 , respectively. Results suggest a target trough ADAMTS-13 of 10 IU dL-1 is feasible but 50 IU dL-1 would not be achievable taking into account volume required. Conclusions Further work is needed to compare treatment of congenital TTP with PI vs. recombinant ADAMTS-13. PI may provide longer duration of ADAMTS-13 effect, but is limited by plasma volume required, whereas recombinant therapy can provide a higher ADAMTS-13 peak. We propose that investigation of interindividual clearance of ADAMTS-13 is necessary to optimize treatment and provide the rationale for dose and frequency of prophylaxis.

Magnetism in semiconducting molybdenum dichalcogenides

Transition metal dichalcogenides (TMDs) are interesting for understanding the fundamental physics of two-dimensional (2D) materials as well as for applications to many emerging technologies, including spin electronics. Here, we report the discovery of long-range magnetic order below T _M = 40 and 100 K in bulk semiconducting TMDs 2H-MoTe₂ and 2H-MoSe₂, respectively, by means of muon spin rotation (μSR), scanning tunneling microscopy (STM), and density functional theory (DFT) calculations. The μSR measurements show the presence of large and homogeneous internal magnetic fields at low temperatures in both compounds indicative of long-range magnetic order. DFT calculations show that this magnetism is promoted by the presence of defects in the crystal. The STM measurements show that the vast majority of defects in these materials are metal vacancies and chalcogen-metal antisites, which are randomly distributed in the lattice at the subpercent level. DFT indicates that the antisite defects are magnetic with a magnetic moment in the range of 0.9 to 2.8 μ_B. Further, we find that the magnetic order stabilized in 2H-MoTe₂ and 2H-MoSe₂ is highly sensitive to hydrostatic pressure. These observations establish 2H-MoTe₂ and 2H-MoSe₂ as a new class of magnetic semiconductors and open a path to studying the interplay of 2D physics and magnetism in these interesting semiconductors.

Chrono-Pharmacological Study of Once Daily Curative Dose of a Low Molecular Weight Heparin (200IU antiXa/kg of Dalteparin) in Ten Healthy Volunteers

Low molecular weight heparin (LMWH) is currently prescribed for the treatment of deep vein thrombosis at the dose of 100 IU antiXa/kg twice daily or at a dose of 175 IU antiXa/kg once daily with a similar efficacy. We decided to study the chrono-pharmacology of curative dose of LMWH once daily administrated according to the one previously described with unfractionated heparin (UFH).

Ten healthy volunteers participated in an open three-period crossover study according to three 24 h cycles, separated by a wash-out interval lasting 7 days: one control cycle without injection, two cycles with subcutaneous injection of 200 IU antiXa/kg of Dalteparin (Fragmin®) at 8 a.m. or at 8 p.m. Parameters of heparin activity were analysed as maximal values and area under the curve.

Activated partial thromboplastin time (APTT), thrombin time (TT), prothrombin time (PT) and tissue factor pathway inhibitor (TFPI) were higher after 8 p.m. injection than after 8 a.m. injection (p <0.05) while no chrono-pharmacological variation of anti factor Xa (AXa) activity was observed. Thus the biological anticoagulant effect of 200 IU antiXa/kg of Dalteparin seems to be higher after an evening injection than after a morning injection.

A chrono-therapeutic approach with LMWH, as prescribed once daily, deserves further investigation since our results suggest that a preferential injection time may optimise the clinical efficacy of these LMWH.

The role of ADAMTS-13 in the coagulopathy of sepsis

The interaction between platelets and the vessel wall is mediated by various receptors and adhesive proteins, of which von Willebrand factor (VWF) is the most prominent. The multimeric size of VWF is an important determinant of a more intense platelet-vessel wall interaction, and is regulated by the VWF-cleaving protease ADAMTS-13. A deficiency in ADAMTS-13 leads to higher concentrations of ultralarge VWF multimers and pathological platelet-vessel wall interactions, in its most typical and extreme form leading to thrombocytopenic thrombotic purpura, a thrombotic microangiopathy characterized by thrombocytopenia, non-immune hemolysis, and organ dysfunction. Thrombotic microangiopathy associated with low levels of ADAMTS-13 may be a component of the coagulopathy observed in patients with sepsis. Here, we review the potential role of ADAMTS-13 deficiency and ultralarge VWF multimers in sepsis, and their relationship with sepsis severity and prognosis. In addition, we discuss the possible benefit of restoring ADAMTS-13 levels or reducing the effect of ultralarge VWF as an adjunctive treatment in patients with sepsis.

Caplacizumab reduces the frequency of major thromboembolic events, exacerbations and death in patients with acquired thrombotic thrombocytopenic purpura

Essentials Acquired thrombotic thrombocytopenic purpura (aTTP) is linked with significant morbidity/mortality. Caplacizumab's effect on major thromboembolic (TE) events, exacerbations and death was studied. Fewer caplacizumab-treated patients had a major TE event, an exacerbation, or died versus placebo. Caplacizumab has the potential to reduce the acute morbidity and mortality associated with aTTP.

SUMMARY

Background Acquired thrombotic thrombocytopenic purpura (aTTP) is a life-threatening autoimmune thrombotic microangiopathy. In spite of treatment with plasma exchange and immunosuppression, patients remain at risk for thrombotic complications, exacerbations, and death. In the phase II TITAN study, treatment with caplacizumab, an anti-von Willebrand factor Nanobody® was shown to reduce the time to confirmed platelet count normalization and exacerbations during treatment. Objective The clinical benefit of caplacizumab was further investigated in a post hoc analysis of the incidence of major thromboembolic events and exacerbations during the study drug treatment period and thrombotic thrombocytopenic purpura-related death during the study. Methods The Standardized Medical Dictionary for Regulatory Activities (MedDRA) Query (SMQ) for 'embolic and thrombotic events' was run to investigate the occurrence of major thromboembolic events and exacerbations in the safety population of the TITAN study, which consisted of 72 patients, of whom 35 received caplacizumab and 37 received placebo. Results Four events (one pulmonary embolism and three aTTP exacerbations) were reported in four patients in the caplacizumab group, and 20 such events were reported in 14 patients in the placebo group (two acute myocardial infarctions, one ischemic stroke, one hemorrhagic stroke, one pulmonary embolism, one deep vein thrombosis, one venous thrombosis, and 13 aTTP exacerbations). Two of the placebo-treated patients died from aTTP during the study. Conclusion In total, 11.4% of caplacizumab-treated patients and 43.2% of placebo-treated patients experienced one or more major thromboembolic events, experienced an exacerbation, or died. This analysis shows the potential for caplacizumab to reduce the risk of major thromboembolic morbidities and mortality associated with aTTP.

Consensus on the standardization of terminology in thrombotic thrombocytopenic purpura and related thrombotic microangiopathies

Essentials An international collaboration provides a consensus for clinical definitions. This concerns thrombotic microangiopathies and thrombotic thrombocytopenic purpura (TTP). The consensus defines diagnosis, disease monitoring and response to treatment. Requirements for ADAMTS-13 are given.

SUMMARY

Background Thrombotic thrombocytopenic purpura (TTP) and hemolytic-uremic syndrome (HUS) are two important acute conditions to diagnose. Thrombotic microangiopathy (TMA) is a broad pathophysiologic process that leads to microangiopathic hemolytic anemia and thrombocytopenia, and involves capillary and small-vessel platelet aggregates. The most common cause is disseminated intravascular coagulation, which may be differentiated by abnormal coagulation. Clinically, a number of conditions present with microangiopathic hemolytic anemia and thrombocytopenia, including cancer, infection, transplantation, drug use, autoimmune disease, and pre-eclampsia and hemolysis, elevated liver enzymes and low platelet count syndrome in pregnancy. Despite overlapping clinical presentations, TTP and HUS have distinct pathophysiologies and treatment pathways. Objectives To present a consensus document from an International Working Group on TTP and associated thrombotic microangiopathies (TMAs). Methods The International Working Group has proposed definitions and terminology based on published information and consensus-based recommendations. Conclusion The consensus aims to aid clinical decisions, but also future studies and trials, utilizing standardized definitions. It presents a classification of the causes of TMA, and criteria for clinical response, remission and relapse of congenital and immune-mediated TTP.

Retrospective comparative analysis of cardiovascular implantable electronic device infections with and without the use of antibacterial envelopes

BACKGROUND

Cardiovascular implantable electronic device (CIED) infections are associated with morbidity and mortality. Peri-operative systemic intravenous antibiotic prophylaxis reduces the rate of CIED infections. AIGIS_Rx, a polymer envelope implanted with the CIED, releases minocycline and rifampin, and has been introduced to reduce infections.

METHODS

Retrospective review of 184 patients who underwent CIED implantation was conducted. Ninety-two patients were implanted with an AIGIS_Rx envelope (AIGIS_Rx group) and 92 patients were not implanted with an AIGIS_Rx envelope (control group). Data were collected on demographics and risk factors for CIED infections (i.e. congestive heart failure, renal insufficiency, chronic kidney disease, oral anticoagulant use, chronic steroid use, need for lead replacement or revision, temporary pacing, early re-intervention, and having more than two leads in place). Rates of implantation success, major infections and mortality were compared between the AIGIS_Rx group and the control group.

RESULTS

The AIGIS_Rx group had longer hospitalizations (6.8±10.7 days vs 3.1±5.2 days; P=0.001), higher chronic corticosteroid use, higher rates of replacement or revision (51.1% vs 8.7%; P=0.001), and a greater proportion of devices with more than two intracardiac leads (42.4% vs 29.3%; P=0.03) than the control group. Successful implantation occurred in 97% of patients in both groups. Major infection was seen in 5.4% of cases in the AIGIS_Rx group and 1.1% of cases in the control group (P=0.048). Device removal was conducted in 3.3% of cases in the AIGIS_Rx group compared with 1.1% of cases in the control group (P=0.16). There were two deaths in the AIGIS_Rx group. Organisms cultured were meticillin-resistant Staphylococcus aureus, meticillin-susceptible S. aureus and Enterococcus faecalis.

CONCLUSION

The AIGIS_Rx group had higher rates of major infection but also higher risk factors compared with the control group. The rate of device extraction and CIED-related mortality was higher in the AIGIS_Rx group than in the control group.

Effects of nutrient content claims, sports celebrity endorsements and premium offers on pre-adolescent children's food preferences: experimental research

OBJECTIVES

To assess pre-adolescent children's responses to common child-oriented front-of-pack food promotions.

METHODS

Between-subjects, web-based experiment with four front-of-pack promotion conditions on energy-dense and nutrient-poor (EDNP) foods: no promotion [control]; nutrient content claims; sports celebrity endorsements (male athletes) and premium offers. Participants were 1302 grade 5 and 6 children (mean age 11 years) from Melbourne, Australia. Participants chose their preferred product from a randomly assigned EDNP food pack and comparable healthier food pack then completed detailed product ratings. Child-oriented pack designs with colourful, cartooned graphics, fonts and promotions were used.

RESULTS

Compared to the control condition, children were more likely to choose EDNP products featuring nutrient content claims (both genders) and sports celebrity endorsements (boys only). Perceptions of nutritional content were enhanced by nutrient content claims. Effects of promotions on some product ratings (but not choice) were negated when children referred to the nutrition information panel. Premium offers did not enhance children's product ratings or choice.

CONCLUSIONS

Nutrient content claims and sports celebrity endorsements influence pre-adolescent children's preferences towards EDNP food products displaying them. Policy interventions to reduce the impact of unhealthy food marketing to children should limit the use of these promotions.

Characterization of the complications associated with plasma exchange for thrombotic thrombocytopaenic purpura and related thrombotic microangiopathic anaemias: a single institution experience

Background

Plasma exchange (PEX) is a life-saving therapeutic procedure in patients with thrombotic thrombocytopaenic purpura (TTP) and other thrombotic microangiopathic anaemias (TMAs). However, it may be associated with significant complications, exacerbating the morbidity and mortality in this patient group.

Study Design and Methods

We reviewed all PEX procedures over a 72-month period, following the exclusive introduction of solvent–detergent double viral-inactivated plasma in high-volume users, such as TTP, in the United Kingdom (UK). We documented allergic reactions to plasma, citrate reactions, complications relating to central venous access insertion and venous thrombotic events (VTE) in 155 patient episodes and >2000 PEX procedures.

Results

The overall complication rate was low. Allergic plasma reactions occurred in 6·45% of the cohort with only one episode of acute anaphylaxis. Similarly, VTEs were 6·45%, not significantly greater than in medical patients receiving thromboprophylaxis, despite added potential risk factors in TTP. Citrate reactions were the most frequent complication documented, but toxicity was significantly reduced by administration of further calcium infusions during the PEX procedure. There were no serious central line infections and no catheter thrombosis.

Conclusion

Our data confirms that PEX continues to be a life-saving procedure in the acute TTP setting and, the procedure was not associated with an increased mortality and limited morbidity.

Rituximab for thrombotic thrombocytopenic purpura: benefit of early administration during acute episodes and use of prophylaxis to prevent relapse

BACKGROUND

Rituximab has been documented in the treatment of acute (≤ 3 days from admission), relapsed/refractory thrombotic thrombocytopenic purpura (TTP) and given as prophylaxis in selected cases to prevent acute relapse. The precise timing of rituximab in acute TTP has not been determined.

OBJECTIVE

To perform a retrospective analysis of rituximab use in a large TTP referral center over an 8-year period.

PATIENTS/METHODS

We assessed response to treatment and outcome for all patients treated with rituximab, including 91 patients presenting with 104 episodes of acute TTP and 15 patients given rituximab as prophylaxis to prevent relapse. In the acute TTP group we assessed the benefit of giving early (≤ 3 days from admission) vs. later (> 3 days) rituximab.

RESULTS

In acute de novo TTP, previously untreated with rituximab, rituximab was given ≤ 3 days from admission to 54 patients and > 3 days from admission to 32 patients. Earlier administration (≤ 3 days) was associated with faster attainment of remission (12 vs. 20 days, P < 0.001), fewer plasma exchanges (16 vs. 24, P = 0.03) and shorter hospital stay (16 vs. 23 days, P = 0.01). Eighty-two patients (95%) achieved complete remission within 14 days (4-52 days); four patients died acutely. Eleven out of 82 (13.4%) relapsed at a median of 24 months (4-49 months). Rituximab prophylaxis was associated with normalization of ADAMTS13 levels within 3 months in all but one case, with only one acute relapse at follow-up.

CONCLUSIONS

Although limited by being retrospective and non-randomized, this study demonstrates the potential benefit of early administration of rituximab in acute TTP, and prophylactic use to prevent acute relapse.

A phenotype-genotype correlation of ADAMTS13 mutations in congenital thrombotic thrombocytopenic purpura patients treated in the United Kingdom

BACKGROUND

ADAMTS13 mutations play a role in thrombotic thrombocytopenic purpura (TTP) pathogenesis.

OBJECTIVES

To establish a phenotype-genotype correlation in a cohort of congenital TTP patients.

PATIENTS/METHODS

Clinical history and ADAMTS13 activity, antigen and anti-ADAMTS13 antibody assays were used to diagnose congenital TTP, and DNA sequencing and in vitro expression were performed to identify the functional effects of the ADAMTS13 mutations responsible.

RESULTS

Seventeen (11 novel) ADAMTS13 mutations were identified in 17 congenital TTP patients. All had severely reduced ADAMTS13 activity and antigen levels at presentation. Six patients with pregnancy-associated TTP and six patients with childhood TTP were homozygous or compound heterozygous for ADAMTS13 mutations located in the metalloprotease (MP), cysteine-rich, spacer and/or distal thrombospondin type 1 domains. The adults had TTP precipitated by pregnancy, and had overall higher antigen levels (median, 30 ng mL(-1) ; range, < 10-57 ng mL(-1) ) than the children (median, 14 ng mL(-1) ; range, < 10-40 ng mL(-1)). Presentation in the neonatal period was associated with more intensive treatment requirements. The two neonates with the most severe phenotype had mutations in the first thrombospondin type 1 motif of ADAMTS13 (p.R398C, p.R409W, and p.Q436H). Using transfected HEK293T cells, we have shown that p.R398C and p.R409W block ADAMTS13 secretion, whereas p.Q436H allows secretion at reduced levels.

CONCLUSIONS

This study confirms the heterogeneity of ADAMTS13 defects and an association between ADAMTS13 genotypes and TTP phenotype.

Postpartum aHUS secondary to a genetic abnormality in factor H acquired through liver transplantation

We report here a young female who underwent a successful deceased donor liver transplant for hepatic vein thrombosis. Five years after transplantation she developed postpartum atypical hemolytic uremic syndrome (aHUS). She did not recover renal function. Mutation screening of complement genes in her DNA did not show any abnormality. Mutation screening of DNA available from the donor showed a nonsense CFH mutation leading to factor H deficiency. Genotyping of the patient showed that she was homozygous for an aHUS CD46 at-risk haplotype. In this individual, the development of aHUS has been facilitated by the combination of a trigger (pregnancy), an acquired rare genetic variant (CFH mutation) and a common susceptibility factor (CD46 haplotype).

Epidemiological study of severe febrile reactions in young children in Western Australia caused by a 2010 trivalent inactivated influenza vaccine

BACKGROUND

The 2010 influenza vaccination program for children aged 6 months to 4 years in Western Australia (WA) was suspended following reports of severe febrile reactions, including febrile convulsions, following vaccination with trivalent inactivated influenza vaccine (TIV).

METHODS

To investigate the association between severe febrile reactions and TIV, three studies were conducted: (i) rates of febrile convulsions within 72 h of receiving TIV in 2010 were estimated by vaccine formulation and batch; (ii) numbers of children presenting to hospital emergency departments with febrile convulsions from 2008 to 2010 were compared; and (iii) a retrospective cohort study of 360 children was conducted to compare the reactogenicity of available TIV formulations.

FINDINGS

In 2010, an estimated maximum of 18,816 doses of TIV were administered and 63 febrile convulsions were recorded, giving an estimated rate of 3.3 (95% CI 2.6 to 4.2) per 1000 doses of TIV administered. The odds of a TIV-associated febrile convulsion was highly elevated in 2010 (p<0.001) and was associated with the vaccine formulations of one manufacturer-Fluvax and Fluvax Junior (CSL Biotherapies). The risk of both febrile convulsions (p<0.0001) and other febrile reactions (p<0.0001) was significantly greater for Fluvax formulations compared to the major alternate brand. The risk of febrile events was not associated with prior receipt of TIV or monovalent 2009 H1N1 pandemic vaccine. The biological cause of the febrile reactions is currently unknown.

INTERPRETATION

One brand of influenza vaccine was responsible for the increase in febrile reactions, including febrile convulsions. Until the biological reason for this is determined and remediation undertaken, childhood influenza vaccination programs should not include Fluvax-type formulations and enhanced surveillance for febrile reactions in children receiving TIV should be undertaken.

Human leukocyte antigen association in idiopathic thrombotic thrombocytopenic purpura: evidence for an immunogenetic link

BACKGROUND

Thrombotic thrombocytopenic purpura (TTP) is a rare, acute, life-threatening disorder, associated with a deficiency in ADAMTS 13. The majority of acute, idiopathic, adult TTP cases are associated with anti-ADAMTS 13 IgG antibodies. However, the factor(s) precipitating an acute TTP episode are not always obvious; indeed, a multifactorial etiology is likely.

OBJECTIVES AND METHODS

DNA was used for human leukocyte antigen (HLA) class II typing, using polymerase chain reaction (PCR)-sequence-specific primer and PCR-sequence-specific oligonucleotide probe to methodology to investigate 50 European acquired idiopathic TTP cases.

RESULTS

There was an increase in the frequency of HLA-DQB1*0301 (HLA-DQ7) in patients with TTP as compared with controls [58.0% vs. 34.5% (P=0.048)]. The frequencies of HLA-DRB1*11 and HLA-DRB3* were also significantly increased in TTP patients as compared with controls [44.0% vs. 12.0% (P=0.0024) and 84.0% vs. 58.0% (P=0.024)], although it remains uncertain whether susceptibility is influenced by HLA-DQ or HLA-DR molecules or other genes in this haplotype. The frequencies of HLA-DRB1*04 and HLA-DRB4 (HLA-DR53) were significantly decreased in the patient group as compared with controls [10.0% vs. 35.0% and 26.0% vs. 61.5% (P=0.0096 and P=0.0024, respectively)], and may have a protective effect against the development of TTP.

CONCLUSION

Analysis identified HLA class II types associated with susceptibility to and a protective effect against the development of acute acquired TTP in European patients. This provides the first description of a genetic factor predicting the risk of developing acquired antibody-mediated TTP.

Cardiac involvement in acute thrombotic thrombocytopenic purpura: association with troponin T and IgG antibodies to ADAMTS 13

INTRODUCTION

Evidence for cardiac involvement in thrombotic thrombocytopenic purpura (TTP) is uncommonly described.

METHODOLOGY

We retrospectively reviewed 41 patients assessing troponin T as a marker for cardiac involvement in acute TTP with clinical symptoms, electrocardiograms (ECG) and echocardiograms. A histopathological review of five patients who died of acute TTP was also undertaken.

RESULTS

In 54% (22/41) of patients, troponin T was >or=0.05microg L(-1) (normal range 0-0.01 microg L(-1)). Half (12/22) had cardiac symptoms and 8/22 with a raised troponin T reported chest pain. ECG changes were present in 62% of patients with a raised troponin T. Median anti-ADAMTS 13 IgG antibody was significantly higher (P=0.018) in patients with troponin T>or=0.05 microg L(-1) (58.5% (range 17-162%), compared with patients with troponin T<0.05 microg L(-1) (35%, range 9-134%). Patients who died had higher troponin T levels (median 0.305 microg L(-1)) and raised anti-ADAMTS 13 IgG (median 66.5%). On admission, there were no deaths in those with troponin T

CONCLUSION

Clinical symptoms, ECG changes and echocardiograms are poor predictors of cardiac disease in acute TTP. Troponin T is specific for cardiac muscle and a sensitive marker of myocardial damage. In TTP patients, raised levels (>or=0.05 microg L(-1)) signify myocardial necrosis associated with microvascular thrombi. Mortality and acute morbidity was associated with higher admission troponin T and raised IgG antibody (>67%) to ADAMTS 13.

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MESH Headings

• ADAM Proteins/immunology
• ADAMTS13 Protein
• Acute Disease
• Autoantibodies/blood
• Biomarkers/blood
• Heart Diseases/diagnosis
• Heart Diseases/mortality
• Humans
• Immunoglobulin G
• Morbidity
• Mortality
• Purpura, Thrombotic Thrombocytopenic/complications
• Purpura, Thrombotic Thrombocytopenic/epidemiology
• Purpura, Thrombotic Thrombocytopenic/mortality
• Retrospective Studies
• Troponin T/blood

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Affiliation(s)

C Hughes Department of Haematology, University College London Hospitals, London, UK
J R McEwan
I Longair
S Hughes
H Cohen
S Machin
M Scully

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Prevalence of the ADAMTS-13 missense mutation R1060W in late onset adult thrombotic thrombocytopenic purpura

BACKGROUND

Thrombotic thrombocytopenic purpura (TTP) is most commonly associated with deficiency or inhibition of von Willebrand factor-cleaving protease (ADAMTS-13) activity. ADAMTS-13 mutations and polymorphisms have been reported in childhood congenital TTP, but their significance in adult onset TTP remains unclear.

OBJECTIVES

We sought to identify common ADAMTS-13 mutations in adults with late onset TTP and to investigate whether they may predispose acute clinical episodes of the disorder in adulthood.

PATIENTS/METHODS/RESULTS

We detected a missense mutation (C3178T) in exon 24 of ADAMTS-13 in 6/53 (11.3%) adult onset TTP patients, but no normal controls (n = 100). Three of the patients had pregnancy-associated TTP; three had chronic relapsing acute idiopathic TTP. C3178T encodes an arginine to tryptophan (R1060W) substitution in the TSP1-7 domain of ADAMTS-13. In vitro expression of mutant and wild-type ADAMTS-13 demonstrated that R1060W caused severe intracellular retention of ADAMTS-13 (<5% secretion) without affecting its metalloprotease activity. One homozygous and five heterozygous patients were identified. No other causative mutations were discovered, yet all six patients had ADAMTS-13 activity levels <5% at presentation (normal: 66-126%). Antibodies/inhibitors to ADAMTS-13 were detected in three/five heterozygous patients, and all six patients had subnormal antigen levels. Six asymptomatic first-degree relatives, including those of two probands with antibodies, were also heterozygous for C3178T; all but one had subnormal ADAMTS-13 activity.

CONCLUSION

The high prevalence of R1060W ADAMTS-13 in adult onset TTP, together with its absence in childhood congenital TTP cases reported elsewhere, suggests it may be a factor in the development of late onset TTP.

Cryosupernatant and solvent detergent fresh-frozen plasma (Octaplas) usage at a single centre in acute thrombotic thrombocytopenic purpura

BACKGROUND

Thrombotic thrombocytopenic purpura (TTP) is an acute, life-threatening disorder and plasma exchange (PEX) remains the mainstay of treatment.

METHODS

We reviewed 50 acute TTP episodes to establish the efficacy and safety of cryosupernatant (CPP) and Octaplas.

RESULTS

Twelve episodes used CPP only and 15 episodes started with CPP and changed to Octaplas. Once Octaplas had been used, it was continued on further admissions. Cryosupernatant was used exclusively in 24% and Octaplas exclusively in 42% of all episodes. The number of citrate reactions and allergic (plasma) reactions were halved in those receiving only Octaplas compared with cryosupernatant. There were 22 line infections and in approximately 70% of cases the infection was associated with a reduction in platelet count. In all 50 episodes, the only documented thrombosis was a superficial non-central vein. In episodes receiving only cryosupernatant or Octaplas, there was no significant difference in the median number of PEX to remission, 7.0 (interquartile range, IQR 5-8.8) and 8.0 (IQR 6.5-22), respectively. Baseline viral screen in all episodes was negative after discharge following an acute episode.

CONCLUSION

There was no difference in number of PEX to remission with cryosupernatant and solvent/detergent fresh-frozen plasma (Octaplas). However, allergic/urticarial and citrate reactions were more common with cryosupernatant. There was no documented viral transmission with either product.

Prevalence of the ADAMTS-13 missense mutation R1060W in late onset adult thrombotic thrombocytopenic purpura

BACKGROUND

Thrombotic thrombocytopenic purpura (TTP) is most commonly associated with deficiency or inhibition of von Willebrand factor-cleaving protease (ADAMTS-13) activity. ADAMTS-13 mutations and polymorphisms have been reported in childhood congenital TTP, but their significance in adult onset TTP remains unclear.

OBJECTIVES

We sought to identify common ADAMTS-13 mutations in adults with late onset TTP and to investigate whether they may predispose acute clinical episodes of the disorder in adulthood.

PATIENTS/METHODS/RESULTS

We detected a missense mutation (C3178T) in exon 24 of ADAMTS-13 in 6/53 (11.3%) adult onset TTP patients, but no normal controls (n = 100). Three of the patients had pregnancy-associated TTP; three had chronic relapsing acute idiopathic TTP. C3178T encodes an arginine to tryptophan (R1060W) substitution in the TSP1-7 domain of ADAMTS-13. In vitro expression of mutant and wild-type ADAMTS-13 demonstrated that R1060W caused severe intracellular retention of ADAMTS-13 (<5% secretion) without affecting its metalloprotease activity. One homozygous and five heterozygous patients were identified. No other causative mutations were discovered, yet all six patients had ADAMTS-13 activity levels <5% at presentation (normal: 66-126%). Antibodies/inhibitors to ADAMTS-13 were detected in three/five heterozygous patients, and all six patients had subnormal antigen levels. Six asymptomatic first-degree relatives, including those of two probands with antibodies, were also heterozygous for C3178T; all but one had subnormal ADAMTS-13 activity.

CONCLUSION

The high prevalence of R1060W ADAMTS-13 in adult onset TTP, together with its absence in childhood congenital TTP cases reported elsewhere, suggests it may be a factor in the development of late onset TTP.

Thrombotic thrombocytopaenic purpura in HIV-infected patients

Thrombotic thrombocytopaenic purpura (TTP) results from deficiency of von Willebrand factor-cleaving protease (vWF-cp) activity. Eight HIV-infected patients presented with TTP, representing 12.5% of all TTP treated at this centre. In four patients presentation with TTP revealed underlying HIV infection, the other four patients were previously known to be HIV infected, with plasma exchange and highly active antiretroviral therapy (HAART) all recovered. Normalization of vWF-cp activity was associated with recovery. Relapse occurred in two patients who discontinued HAART against medical advice, suggesting that HIV has a causal role in this condition. Given the clear benefit from HAART in addition to plasma exchange, these data suggest that all patients presenting with TTP should undergo HIV testing.

Contact tracing of tuberculosis in a school setting and the relevance of BCG in this population

Tuberculosis (TB) remains a worldwide health problem. Treatment, contact tracing and screening of at-risk populations continue to be important issues even in countries with low rates of tuberculosis. In contact tracing, prior BCG vaccination can make interpretation of Mantoux positivity difficult. We had the opportunity to evaluate contacts of a student diagnosed with pulmonary tuberculosis. In the index case's class, 23 of 50 (46%) students screened had TB infection and a further 2 (4%) students had TB disease. Screening was offered to all students in the school (307 students) and 244 students (79%) attended. Students were stratified naturally into classes of ascending age, providing an opportunity to study disease transmission and Mantoux testing in a group who had received BCG at birth. Our findings illustrates that neonatal BCG vaccination has a minimal effect on Mantoux positivity at 12 years and older.

Inhibition of cyclooxygenase-2 aggravates doxorubicin-mediated cardiac injury in vivo

The clinical use of doxorubicin, an anthracycline chemotherapeutic agent, is limited by cardiotoxicity, particularly when combined with herceptin, an antibody that blocks the HER2 receptor. Doxorubicin induces cyclooxygenase-2 (COX-2) activity in rat neonatal cardiomyocytes. This expression of COX-2 limits doxorubicin-induced cardiac cell injury, raising the possibility that the administration of a prostaglandin may protect the heart during the in vivo administration of doxorubicin. Doxorubicin (15 mg/kg) administered to adult male Sprague Dawley rats induced COX-2 expression and activity in cardiac tissue. Prostacyclin generation measured as the excretion of 2,3-dinor-6-keto-PGF(1alpha) also increased, and this was blocked by a COX-2 inhibitor, SC236. In contrast, administration of a COX-1 inhibitor SC560 at a dose that reduced serum thromboxane B2 by more than 80% did not prevent the doxorubicin-induced increase in prostacyclin generation. Doxorubicin increased cardiac injury, detected as a rise in plasma cardiac troponin T, serum lactate dehydrogenase, and cardiomyocyte apoptosis; this was aggravated by coadministration of SC236 but not SC560. The degree of injury in animals treated with a combination of doxorubicin and SC236 was attenuated by prior administration of the prostacyclin analogue iloprost. These data raise the possibility of protecting the heart during the administration of doxorubicin by prior administration of prostacyclin.

Arg-Tyr-Asp (RYD) and Arg-Cys-Asp (RCD) motifs in dendroaspin promote selective inhibition of beta1 and beta3 integrins

Arg-Gly-Asp (RGD) is a unique minimal integrin-binding sequence that is found within several glycoprotein ligands. This sequence has also been found in snake-venom anti-platelet proteins, including the disintegrins and dendroaspin, a natural variant of short-chain neurotoxins isolated from the venom of Dendroaspis jamesonii. In the present study, the motifs RYD and RCD were introduced into the dendroaspin scaffold to replace RGD. Both motifs in dendroaspin caused inhibition of ADP-induced platelet aggregation with IC(50) values of 200 and 300 nM respectively, similar to that of the wild-type RGD motif (170 nM). In comparison with wild-type dendroaspin, both RYD- and RCD-containing dendroaspins were more selective in the inhibition of the adhesion of K562 cells to laminin rather than to fibrinogen and fibronectin, even though they were 10-30-fold less potent at inhibiting K562 cell (containing alpha(5)beta(1) integrin) adhesion to laminin compared with wild-type. Interestingly, the RYD motif produced a similar IC(50) value to the RGD motif at inhibiting A375-SM cell (beta(3) integrin) adhesion to collagen, whereas the RCD motif was approx. 2-6-fold less potent compared with either RGD or RYD. These findings show that the selectivity of dendroaspin binding to beta(1) and beta(3) integrins can be modulated by the introduction of alternative cell recognition sequences.

Evaluation of the role of proline residues flanking the RGD motif of dendroaspin, an inhibitior of platelet aggregation and cell adhesion

The effect of a panel of proline mutants of dendroaspin, an inhibitor of platelet aggregation and cell adhesion, including A(42)-dendroaspin, A(47)-dendroaspin, A(49)-dendroaspin, A(42,47)-dendroaspin and A(47,49)-dendroaspin, was investigated using platelet-aggregation and cell-adhesion assays. Here we show that a single alanine-for-proline substitution did not affect potency when measured as the ability either to inhibit platelet aggregation induced by ADP (IC(50) approximately 170 nM) or to block transfected A375-SM cell adhesion to fibrinogen in the presence of Mn(2+) as compared with wild-type dendroaspin. By comparison, double proline substitution with alanines significantly reduced the potency in both assays by approx. 5-8-fold. These observations, therefore, suggest that proline residues flanking the RGD motif in dendroaspin and other RGD-containing venom proteins, e.g. disintegrins, may contribute to maintaining a favourable conformation for the solvent-exposed RGD site for its recognition by integrin receptors.