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Two cases of sporadic CJD with clotting disorders have been identified, but this may represent a chance event., Sporadic Creutzfeldt-Jakob disease (sCJD) has not been previously reported in patients with clotting disorders treated with fractionated plasma products. We report 2 cases of sCJD identified in the United Kingdom in patients with a history of extended treatment for clotting disorders; 1 patient had hemophilia B and the other von Willebrand disease. Both patients had been informed previously that they were at increased risk for variant CJD because of past treatment with fractionated plasma products sourced in the United Kingdom. However, both cases had clinical and investigative features suggestive of sCJD. This diagnosis was confirmed in both cases on neuropathologic and biochemical analysis of the brain. A causal link between the treatment with plasma products and the development of sCJD has not been established, and the occurrence of these cases may simply reflect a chance event in the context of systematic surveillance for CJD in large populations.

SUMMARYObjective To describe the epidemiology of blood transfusion in children: including the incidence of transfusion, the diagnoses leading to transfusion, donor exposure (DE) and post-transfusion survival. Study design and methods The Epidemiology and Survival of Transfusion Recipients (EASTR) Study was a multi-centre epidemiological study with prospective survival monitoring. Cross-sectional sampling of adult and paediatric transfusion recipients in 29 hospitals was used to select three separate cohorts of red cell (RBC), platelet (PLT) and fresh frozen plasma (FFP) recipients between October 2001 and September 2002. This paper presents the analysis of results for children

Look-back studies of blood transfusion in Creutzfeldt-Jakob disease commonly rely on reported history from surrogate witnesses. Data from the UK Transfusion Medicine Epidemiology Review have been analysed to determine the accuracy of the blood donation history provided by the relatives of cases. Our results show that only a small percentage of cases were found to be registered as donors on UK Blood Service (UKBS) databases when there was no family report of blood donation. In contrast, a history of reported donation was less accurate.

Background Low fibrinogen (Fg) concentrations in trauma haemorrhage are associated with poorer outcomes. Cryoprecipitate is the standard source for Fg administration in the UK and USA and is often given in the later stages of transfusion therapy. It is not known whether early cryoprecipitate therapy improves clinical outcomes. The primary aim of this feasibility study was to determine whether it was possible to administer cryoprecipitate, within 90 min of admission to hospital. Secondary aims were to evaluate laboratory measures of Fg and clinical outcomes including thrombotic events, organ failure, length of hospital stay and mortality. Methods This was an unblinded RCT, conducted at two civilian UK major trauma centres of adult trauma patients (age ≥16 yrs), with active bleeding and requiring activation of the major haemorrhage protocol. Participants were randomised to standard major haemorrhage therapy (STANDARD) (n=22), or to standard haemorrhage therapy plus two early pools of cryoprecipitate (CRYO) (n=21). Results 85% (95% CI: 69–100%) CRYO participants received cryoprecipitate within 90 min, median time 60 min (IQR: 57–76) compared with 108 min (67–147), CRYO and STANDARD arms respectively (P=0.002). Fg concentrations were higher in the CRYO arm and were maintained above 1.8 g litre−1 at all time-points during active haemorrhage. All-cause mortality at 28 days was not significantly different (P=0.14). Conclusions Early Fg supplementation using cryoprecipitate is feasible in trauma patients. This study supports the need for a definitive RCT to determine the effect of early Fg supplementation on mortality and other clinical outcomes. Trial registry number ISRCTN55509212.

Background and Objectives In this study, we compare variant Creutzfeldt-Jakob disease (vCJD) cases definitely linked to blood transfusion, those with a history of blood transfusion in which no donor has developed vCJD and primary cases with no history of blood transfusion. The aim is to determine whether there are any differences in the demographics or clinical phenotype in these groups that might suggest additional cases of transfusion transmission of vCJD. Materials and Methods All cases of vCJD who are old enough to donate blood (i.e. >17 years old) are notified to the UKBTS at diagnosis, regardless of whether they are known to have a blood donation history. A search is then made for donor records and, if found, all components produced and issued to hospitals are identified and their fate determined. Recipient details are then checked against the NCJDRSU register to establish whether there is a match between these individuals and patients who have been diagnosed with vCJD. In the reverse study, attempts are made to trace the donors to all cases reported to have received a blood transfusion and donors' details are checked against the register to determine if any have developed vCJD. Results Of the 177 cases of vCJD diagnosed in the UK as of 1 February 2014, the TMER study identified 15 cases reported to have received a blood transfusion. Transfusion records were unavailable for 4 of these cases, all pre-1980, and in one other case there was no transfusion recorded in the medical notes. Transfusion records were found for 10 cases. One case transfused at symptom onset was excluded from this analysis. The mean age at onset of symptoms of the remaining nine transfusion recipients (four female and five male) was 42·9 years; 57·6 years in the three known transfusion-transmitted cases and 35·5 years in the six not linked cases. In one of these cases, details of components transfused were unavailable, and the remaining five cases received a total of 116 donor exposures with 112 donors identified, none of whom is known to have developed clinical vCJD. To date, five of the 112 identified donors have died and none was certified as dying of vCJD or any other neurological disorder. Two of the transfusion-transmitted cases did not fulfil diagnostic criteria for probable vCJD during life but were confirmed at post-mortem. Both cases were in the older age range (68 and 74 years, respectively), and neither had a positive MRI brain scan. The remaining cases all fulfilled the criteria for the diagnosis of vCJD in life, but two of these had atypical features and were older than the expected age at onset for vCJD. Conclusion In conclusion, it is possible that one or more of the vCJD cases that received a blood transfusion derived from an individual not known to have vCJD were infected by the blood transfusion. However, the evidence for this is weak, and the absence of a past history of transfusion in most cases of vCJD excludes a large number of unrecognised transfusion-transmitted cases.

The study’s objective was to assess the cost-effectiveness of preoperative transfusion compared with no preoperative transfusion in patients with sickle cell disease undergoing low- or medium-risk surgery. Seventy patients with sickle cell disease (HbSS/Ss 0 thal genotypes) undergoing elective surgery participated in a multicentre randomised trial, Transfusion Alternatives Preoperatively in Sickle Cell Disease (TAPS). Here, a cost-effectiveness analysis based on evidence from that trial is presented. A decision-analytic model is used to incorporate long-term consequences of transfusions and acute chest syndrome. Costs and health benefits, expressed as quality-adjusted life years (QALYs), are reported from the ‘within-trial’ analysis and for the decision-analytic model. The probability of cost-effectiveness for each form of management is calculated taking into account the small sample size and other sources of uncertainty. In the range of scenarios considered in the analysis, preoperative transfusion was more effective, with the mean improvement in QALYs ranging from 0.018 to 0.206 per patient, and also less costly in all but one scenario, with the mean cost difference ranging from � £813 to £26. All scenarios suggested preoperative transfusion had a probability of cost-effectiveness >0.79 at a cost-effectiveness threshold of £20 000 per QALY.

Summary Background No consensus exists on whether preoperative blood transfusions are beneficial in patients with sickle-cell disease. We assessed whether perioperative complication rates would be altered by preoperative transfusion. Methods We did a multicentre, randomised trial. Eligible patients were aged at least 1 year, had haemoglobin SS or Sβ 0 thalassaemia sickle-cell-disease subtypes, and were scheduled for low-risk or medium-risk operations. Patients were randomly assigned no transfusion or transfusion no more than 10 days before surgery. The primary outcome was the proportion of clinically important complications between randomisation and 30 days after surgery. Analysis was by intention to treat. Findings 67 (96%) of 70 enrolled patients—33 no preoperative transfusion and 34 preoperative transfusion—were assessed. 65 (97%) of 67 patients had the haemoglobin SS subtype and 54 (81%) were scheduled to undergo medium-risk surgery. 13 (39%) of 33 patients in the no-preoperative-transfusion group had clinically important complications, compared with five (15%) in the preoperative-transfusion group (p=0·023). Of these, 10 (30%) and one (3%), respectively, had serious adverse events. The unadjusted odds ratio of clinically important complications was 3·8 (95% CI 1·2–12·2, p=0·027). 10 (91%) of 11 serious adverse events were acute chest syndrome (nine in the no-preoperative-transfusion group and one in the preoperative-transfusion group). Duration of hospital stay and readmission rates did not differ between study groups. Interpretation Preoperative transfusion was associated with decreased perioperative complications in patients with sickle-cell disease in this trial. This approach could, therefore, be beneficial for patients with the haemoglobin SS subtype who are scheduled to undergo low-risk and medium-risk surgeries. Funding NHS Blood and Transplant.

Acute upper gastrointestinal bleeding (AUGIB) is the commonest reason for hospitalization with hemorrhage in the UK and the leading indication for transfusion of red blood cells (RBCs). Observational studies suggest an association between more liberal RBC transfusion and adverse patient outcomes, and a recent randomised trial reported increased further bleeding and mortality with a liberal transfusion policy. TRIGGER (Transfusion in Gastrointestinal Bleeding) is a pragmatic, cluster randomized trial which aims to evaluate the feasibility and safety of implementing a restrictive versus liberal RBC transfusion policy in adult patients admitted with AUGIB. The trial will take place in 6 UK hospitals, and each centre will be randomly allocated to a transfusion policy. Clinicians throughout each hospital will manage all eligible patients according to the transfusion policy for the 6-month trial recruitment period. In the restrictive centers, patients become eligible for RBC transfusion when their hemoglobin is < 8 g/dL. In the liberal centers patients become eligible for transfusion once their hemoglobin is < 10 g/dL. All clinicians will have the discretion to transfuse outside of the policy but will be asked to document the reasons for doing so. Feasibility outcome measures include protocol adherence, recruitment rate, and evidence of selection bias. Clinical outcome measures include further bleeding, mortality, thromboembolic events, and infections. Quality of life will be measured using the EuroQol EQ-5D at day 28, and the costs associated with hospitalization for AUGIB in the UK will be estimated. Consent will be sought from participants or their representatives according to patient capacity for use of routine hospital data and day 28 follow up. The study has ethical approval for conduct in England and Scotland. Results will be analysed according to a pre-defined statistical analysis plan and disseminated in peer reviewed publications to relevant stakeholders. The results of this study will inform the feasibility and design of a phase III randomized trial. © 2013 Elsevier Inc.

BACKGROUND: To date there have been four instances of infection transmitted through blood transfusions derived from individuals who later developed variant Creutzfeldt-Jakob disease (vCJD). The identification of further transmission of vCJD through this route would have important implications for risk assessment and public health. STUDY DESIGN AND METHODS: Through the UK Transfusion Medicine Epidemiology Review (TMER) the fate of blood donations from individuals who develop vCJD is traced and recipients of labile components are identified. The details of recipients are cross-checked with the register of vCJD cases held at the National CJD Surveillance Unit (NCJDSU) to identify any linkage between donors and recipients. In the reverse study, when individuals with vCJD are found to have a history of blood transfusion the donors of the transfused blood components are traced and their details cross-checked with the vCJD register to identify any missed or unrecognized linkage between donors and recipients. CASE REPORT: A case of vCJD has been identified with a history of blood transfusion in infancy. The donors who provided the components transfused cannot be identified, but a blood donor known to have donated blood to another individual who subsequently developed vCJD could have been a donor to the index case. RESULTS: The at-risk donor is alive 20 years after the relevant donation and continued to donate for some years, until identified as at risk, with 27 other blood components issued for use in patients, none of whom are known to have developed vCJD. CONCLUSION: Circumstantial evidence has raised the possibility that the case in this report represents a further instance of transfusion transmission of vCJD. However, detailed investigation indicates that the pattern of events may have occurred by chance and disease in this individual may have been caused by transmission of bovine spongiform encephalopathy infection, as is the presumed cause in other primary cases of vCJD.

Background The risk to public health of onward transmission of variant Creutzfeldt–Jakob disease (vCJD) via blood transfusion and plasma product administration is of on-going concern, particularly with the recent reported detection of abnormal prion protein in a person with haemophilia. Objectives To describe the history of fractionated plasma product exposure in clinical cases of vCJD in the UK. Methods Through examination of records held at the National CJD Surveillance Unit (from relatives, general practices and hospitals). Results Nine out of 168 UK vCJD cases had a history of receipt of fractionated plasma products on 12 different occasions (1 pre-vCJD risk in 1970, the remaining between 1989–1998). According to the UK CJD Incident Panel risk assessment criteria, 11 were low-risk products and one was low or medium risk. Conclusion It is unlikely that any of the UK vCJD clinical cases to date were infected through exposure to fractionated plasma products. However, the possibility that such transmission may result in vCJD cases in the future cannot be excluded.

To gather data on current preoperative transfusion practice and postoperative complications in sickle cell disease (SCD) as a prelude to a randomised trial.A prospective one year survey of 114 SCD patients undergoing elective surgery in 31 English hospitals was undertaken.43%, 39% and 23% of patients respectively [corrected] received no transfusion, top-up and exchange transfusion preoperatively. Overall postoperative complication rates were 18%, 26% and 17%, with SCD related complications of 12%, 8% and 0% respectively. 85% of patients with [corrected]HbSC/HbSss(+)thalassaemia and 71% of obstetric and gynaecology patients were not transfused preoperatively, whereas 59% patients undergoing ENT procedures and 83% of hip replacements had top-up and exchange transfusions respectively. Multivariable logistic regression analysis revealed that having moderate/high risk procedures was a predictor of postoperative complications (OR 4.9 (95% CL: 1.3 to 18), P = 0.017) [corrected] while preoperative transfusion was not (OR 1.7, (95% CL: [corrected] 0.5 to 6), P = 0.41).The lack of clear benefit of transfusion confirms the need for a randomised controlled trial of transfusion vs. no transfusion in patients with HbSS and HbSss(0)thalassaemia.

This study, conducted for the UK Blood Transfusion Services (UKBTS), evaluated the clinical safety of red cells filtered through a CE-marked prion removal filter (P-Capt™). Patients requiring blood transfusion for elective procedures in nine UK hospitals were entered into a non-randomized open trial to assess development of red cell antibodies to standard red cell (RCC) or prion-filtered red cell concentrates (PF-RCC) at eight weeks and six months post-transfusion. Patients who received at least 1 unit of PF-RCC were compared with a control cohort given RCC only. About 917 PF-RCC and 1336 RCC units were transfused into 299 and 291 patients respectively. Twenty-six new red cell antibodies were detected post-transfusion in 10 patients in each arm, an overall alloimmunization rate of 4.4%. Neither the treatment arm [odds ratio (OR) 0.93, 95% confidence interval (CI) 0.3, 2.5] nor number of units transfused (OR 0.95, 95% CI 0.8, 1.1) had a significant effect on the proportion of patients who developed new alloantibodies. No pan-reactive antibodies or antibodies specifically against PF-RCC were detected. There was no difference in transfusion reactions between arms, and no novel transfusion-related adverse events clearly attributable to PF-RCC were seen. These data suggest that prion filtration of red cells does not reduce overall transfusion safety. This finding requires confirmation in large populations of transfused patients.

Background To date, four instances of probable transfusion–transmission of variant Creutzfeldt–Jakob disease (vCJD) infection have been described, and surviving recipients of vCJD-implicated blood components have been informed that they may be ‘at risk’ of vCJD. Nearly two-thirds of all recipients of vCJD-implicated blood components are deceased, and many died before the vCJD risk was known. The primary aim of this study was to determine retrospectively whether there was evidence that any of the other deceased recipients of vCJD-implicated blood components had any clinical signs or symptoms suggestive of vCJD in life. In addition, pathological material from recipients, stored at the time of surgery or autopsy, was sought to allow testing for evidence of vCJD infection. A secondary aim of the study was to obtain information on invasive healthcare procedures undertaken on recipients following the transfusion to identify the potential for onward transmission of infection. Methods A retrospective review of medical case notes of deceased recipients of vCJD-implicated blood components was carried out, and relevant information was extracted. In cases undergoing post-mortem, details of the findings were obtained. Results The medical case notes of 33 (83%) deceased recipients of vCJD-implicated blood components, not already known to be infected with vCJD, were reviewed. The median age of recipients was 68 years (interquartile range 57–79 years). Almost half (16) were male. The median time from transfusion to death was 175 days (interquartile range 43–701 days). Most (66%) recipients died in hospital. None of the recipients had documented evidence of clinical signs or symptoms suggestive of vCJD. Only two recipients, both of whom died within a year of transfusion, underwent autopsy examination. Neither brain nor peripheral lymphoreticular tissue was available from either recipient, and pathological material was unavailable from any of the other deceased recipients. Almost half of all recipients underwent at least one invasive healthcare procedure post-transfusion. Conclusions A retrospective review of the medical case notes of the deceased recipients of vCJD-implicated blood components found no evidence that any further cases expressed clinical signs or symptoms suggestive of vCJD during life, but only four of the recipients survived for more than 5 years post-transfusion.

Background and Objectives This paper reports the results to 1 March 2006 of an ongoing UK study, the Transfusion Medicine Epidemiological Review (TMER), by the National CJD Surveillance Unit (NCJDSU) and the UK Blood Services (UKBS) to determine whether there is any evidence that Creutzfeldt–Jakob disease (CJD), including sporadic CJD (sCJD), familial CJD (fCJD), and variant CJD (vCJD) is transmissible via blood transfusion. Materials and Methods Sporadic CJD and fCJD cases with a history of blood donation or transfusion are notified to UKBS. All vCJD cases aged > 17 years are notified to UKBS on diagnosis. A search for donation records is instigated and the fate of all donations is identified by lookback. For cases with a history of blood transfusion, hospital and UKBS records are searched to identify blood donors. Details of identified recipients and donors are checked against the NCJDSU register to establish if there are any matches. Results CJD cases with donation history: 18/31 vCJD, 3/93 sCJD, and 3/5 fCJD cases reported as blood donors were confirmed to have donated labile components transfused to 66, 20, and 11 recipients respectively. Two vCJD recipients have appeared on the NCJDSU register as confirmed and probable vCJD cases. The latter developed symptoms of vCJD 6.5 years and 7.8 years respectively after receiving non-leucodepleted red blood cells (RBCs) from two different donors who developed clinical symptoms approximately 40 and 21 months after donating. A third recipient, given RBC donated by a further vCJD case approximately 18 months before onset of clinical symptoms, had abnormal prion protein in lymphoid tissue at post-mortem (5-years post-transfusion) but had no clinical symptoms of vCJD. CJD cases with history of transfusion: Hospital records for 7/11 vCJD and 7/52 sCJD cases included a history of transfusion of labile blood components donated by 125 and 24 donors respectively. Two recipients who developed vCJD were linked to donors who had already appeared on the NCJDSU register as vCJD cases (see above). No further links were established. Conclusion This study has identified three instances of probable transfusion transmission of vCJD infection, including two confirmed clinical cases and one pre- or sub-clinical infection. This study has not provided evidence, to date, of transmission of sCJD or fCJD by blood transfusion, but data on these forms of diseases are limited.

Summary Background Variant Creutzfeldt-Jakob disease (vCJD) is a novel human prion disease caused by infection with the agent of bovine spongiform encephalopathy (BSE). Epidemiological evidence does not suggest that sporadic CJD is transmitted from person to person via blood transfusion, but this evidence may not apply to vCJD. We aimed to identify whether vCJD is transmissible through blood transfusion. Methods The national CJD surveillance unit reported all cases of probable or definite vCJD to the UK blood services, which searched for donation records at blood centres and hospitals. Information on named recipients and donors was provided to the surveillance unit to establish if any matches existed between recipients or donors and the database of cases of vCJD. Recipients were also flagged at the UK Office of National Statistics to establish date and cause of death. Findings 48 individuals were identified as having received a labile blood component from a total of 15 donors who later became vCJD cases and appeared on the surveillance unit's register. One of these recipients was identified as developing symptoms of vCJD 6·5 years after receiving a transfusion of red cells donated by an individual 3·5 years before the donor developed symptoms of vCJD. Interpretation Our findings raise the possibility that this infection was transfusion transmitted. Infection in the recipient could have been due to past dietary exposure to the BSE agent. However, the age of the patient was well beyond that of most vCJD cases, and the chance of observing a case of vCJD in a recipient in the absence of transfusion transmitted infection is about 1 in 15 000 to 1 in 30 000.

Genetic variation is known to account for up to 70% of the wide variation in platelet function observed in healthy individuals. We have shown that platelet concentrates (PC) that are highly activated when collected by apheresis are produced from donors whose platelets are highly responsive to adenosine diphosphate (ADP) and collagen related peptide (CRP-XL) in vitro(high responder donors) with activation being measured by P-selectin expression and fibrinogen binding. The effect of this variation in donors on the outcome from platelet transfusion is unknown. The aim of the PROmPT trial (Platelet Responsiveness and Outcome from Platelet Transfusion, ISRCTN 56366401) was to test the hypothesis that PC following transfusion from high responder donors are cleared more rapidly from the circulation than PC from low responder donors. Method We established a cohort of 1,000 blood donors phenotyped for responsiveness to CRP (0.1-0.5 µg/mL) or ADP (10-7M) by flow cytometry. A sub-set of these individuals (26 high and 19 low responder donors) who reproducibly had global responses, i.e. not outliers for just one agonist, in the top and bottom 10% of the cohort were selected to supply apheresis platelets collected on the Terumo Trima system for the trial. The trial was designed as a parallel group, semi-randomised double-blinded trial in stable haematology patients who required prophylactic platelet transfusions. Based on 80% power, a 5% significance level, and a presumed 10% dropout, 100 patients (with the aim of 50 receiving a unit from high responders and 50 from low responders) were required to detect a mean difference of 7x109/L in the primary endpoint of the 1 hour (10-90 min) count increment (CI) between the high and low responder PC. Patients were randomised to receive a single PC from either a high or low responder donor when both were available. If only one type of PC was available then patients received that PC. Patients with factors known to affect platelet CI were excluded. In addition, 30 patients acted as controls, receiving non-trial PC from random donors. PCs were ABO and Rh compatible. Patients were followed up for 5 days or until their next platelet transfusion. Secondary outcomes included an assessment of bleeding score (modified WHO score) both by the patient and the clinician, 24 hour (12-36 hours) CI, as well as time to next platelet transfusion, and red cell transfusion requirements. CIs were adjusted for confounding factors that affect platelet increments, these were age and dose of PC, and body surface area. Results Baseline characteristics of patients were adequately balanced between groups. Fifty one patients received a PC from low responder donors, and 49 from high responder donors (47 of which were randomised and 53 non-randomised) and 30 patients received non-trial units (2 non trial transfusions were excluded from final analysis). There was no significant difference in the adjusted 1 hour CI, in patients receiving platelets from high or low responder donors (high response 21.04 versus low response 23.34x109/L; difference 2.30, 95%CI -1.09 to 5.69, p = 0.18) or the 24 hour platelet CI (high response 12.9 versus low response 14.31x109/L; difference 1.41, 95% CI -1.96 to 4.78, p = 0.41). There were no significant differences in all other secondary outcomes between patients receiving PC from high or low responder donors, including maximum bleeding scores (odds ratio 0.78, 95%confidence interval 0.29 to 2.16, p=0.64) and bleeding rates (number of days with Grade 2-4 bleed) (rate ratio was 0.70, 95% confidence interval 0.16 to 2.97, p = 0.63). In addition, there was no significant difference in 1 hour CI between patients receiving non-trial units and those from high (p = 0.28) or low responders (p = 0.95) or in any secondary outcomes. Conclusions Results from this trial suggest that in a setting of prophylactic transfusion, the platelet responsiveness of the donor does not affect platelet count increments, bleeding scores, inter-transfusion interval or red cell usage in recipients. Further studies will be required to determine whether PC derived from high responders may be more efficacious in patients who are actively bleeding at the time of transfusion. Disclosures No relevant conflicts of interest to declare.

Abstract 1 Background The effectiveness of prophylactic platelets (plts) to prevent bleeding in patients with hematological malignancies remains unclear. The aim of this trial was to test the hypothesis that a policy of no-prophylactic plt transfusions (PltTx) is as effective and safe as a policy of prophylactic PltTx. Methods TOPPS was a randomized, parallel group, open-label, non-inferiority trial that recruited from 14 UK and Australian hospitals (ISRCTN08758735). The primary outcome was proportion of patients with a clinically significant bleed, defined as ≥WHO Grade 2, up to 30 days (d) from randomization. Non-inferiority margin was defined as a 15% difference in proportion of patients experiencing the primary outcome. Adult patients were eligible if they had a hematological malignancy, were receiving chemotherapy or stem cell transplant (SCT) and expected to be thrombocytopenic for at least 5 days. Patients were randomized by centralized computer system to receive either prophylactic PltTx if plt count was Results Recruitment began August 2006 and closed in August 2011. Of 1093 patients screened, 600 patients were randomized (301 no-prophylaxis, 299 prophylaxis). Baseline characteristics were well matched. 70% patients in both arms received autologous SCT (autoSCT). The majority of patients in both arms had complete bleeding data recorded [median 30d (IQR 29 to 30) no-prophylaxis arm, median 30d (IQR 30 to 30) prophylaxis arm]. Two patients (1 in each arm) withdrew prior to any data collection. Most PltTx in both arms were given according to protocol (no-prophylaxis 450/504 (89%) vs prophylaxis 810/894 (91%). Fewer patients in the no-prophylaxis group received PltTx (176/300, 59%) vs. prophylaxis group (266/298, 89%) [OR 0.14 (95% CI 0.09 to 0.23]; and they also received fewer PltTx overall [no-prophylaxis mean 1.7 PltTx (SD 2.6) vs. prophylaxis mean 3.0 PltTxs (SD 3.2); rate ratio 0.62, 95% CI 0.51 to 0.74]. Average number of days with plt count A WHO grade 2–4 bleed occurred in 151/300 patients (50%) in the no-prophylaxis group compared to 128/298 (43%) in the prophylaxis group (adjusted difference in proportions 8.4%, 90% CI 1.7 to 15.2%: p-value for non-inferiority 0.06). This study therefore did not prove its main aim, that a no-prophylaxis policy is non-inferior to prophylaxis. The time to the first grade 2–4 bleed was significantly shorter in the no-prophylaxis group (Fig. 1). Patients in the no-prophylaxis group averaged 1.7d (SD 2.9) with a WHO grade 2–4 bleed during follow-up, vs. 1.2d (SD 2.0) in the prophylactic group [rate ratio 1.52, 95% CI 1.14 to 2.03]. Whilst there were more grade 3–4 bleeds in the no-prophylaxis group (6/300) compared to the prophylaxis group (1/298) this did not reach statistical significance (OR 6.05, 95% CI 0.73 to 279.72, p = 0.13). Only 2 of these 7 patients had a plt count For all patients, there was no significant difference between treatment groups in period of thrombocytopenia, number of days in hospital, or number of SAEsexperienced. Discussion This multicenter study has not shown that a no-prophylaxis PltTx policy is non-inferior to prophylaxis. Patients in the no-prophylaxis group had more days with a WHO grade 2 or above bleed, and a shorter time to first bleed. Further analysis is needed to determine whether these findings apply to all subgroups of patients. Despite a role for prophylactic platelet transfusions, rates of bleeding in patients remain high. Funding NHS Blood and Transplant & Australian Red Cross Blood Service Disclosures: No relevant conflicts of interest to declare.