Antibody prevalence after three or more COVID-19 vaccine doses in individuals who are immunosuppressed in the UK: a cross-sectional study from MELODY.

BACKGROUND: In the UK, additional COVID-19 vaccine booster doses and treatments are offered to people who are immunosuppressed to protect against severe COVID-19, but how best to choose the individuals that receive these vaccine booster doses and treatments is unclear. We investigated the association between seropositivity to SARS-CoV-2 spike protein with demographic, disease, and treatment-related characteristics after at least three COVID-19 vaccines in three cohorts of people who are immunosuppressed. METHODS: In a cross-sectional study using UK national disease registries, we identified, contacted, and recruited recipients of solid organ transplants, participants with rare autoimmune rheumatic diseases, and participants with lymphoid malignancies who were 18 years or older, resident in the UK, and who had received at least three doses of a COVID-19 vaccine. The study was open to recruitment from Dec 7, 2021, to June 26, 2022. Participants received a lateral flow immunoassay test for SARS-CoV-2 spike antibodies to complete at home, and an online questionnaire. Multivariable logistic regression was used to estimate the mutually adjusted odds of seropositivity against each characteristic. FINDINGS: Between Feb 14 and June 26, 2022, we screened 101 972 people (98 725 invited, 3247 self-enrolled) and recruited 28 411 (27·9%) to the study. 23 036 (81·1%) recruited individuals provided serological data. Of these, 9927 (43·1%) were recipients of solid organ transplants, 6516 (28·3%) had rare autoimmune rheumatic diseases, and 6593 (28·6%) had lymphoid malignancies. 10 485 (45·5%) participants were men and 12 535 (54·4%) were women (gender was not reported for 16 [<0·1%] participants), and 21661 (94·0%) participants were of White ethnicity. The median age of participants with solid organ transplants was 60 years (SD 50-67), with rare autoimmune rheumatic diseases was 65 years (54-73), and with lymphoid malignancy was 69 years (61-75). Of the 23 036 participants with serological data, 6583 (28·6%) had received three vaccine doses, 14 234 (61·8%) had received four vaccine doses, and 2219 (9·6%) had received five or more vaccine doses. IgG anti-spike antibodies were undetectable in 2310 (23·3%) of 9927 patients with solid organ transplants, 922 (14·1%) of 6516 patients with rare autoimmune rheumatic diseases, and 1366 (20·7%) of 6593 patients with lymphoid malignancies. In all groups, seropositivity was associated with younger age, higher number of vaccine doses (ie, five vs three), and previous COVID-19. Immunosuppressive medication reduced the likelihood of seropositivity: the lowest odds of seropositivity were found in recipients of solid organ transplants receiving a combination of an anti-proliferative agent, a calcineurin inhibitor, and steroids, and those with rare autoimmune rheumatic diseases or lymphoid malignancies treated with anti-CD20 therapies. INTERPRETATION: Approximately one in five recipients of solid organ transplants, individuals with rare autoimmune rheumatic diseases, and individuals with lymphoid malignancies have no detectable IgG anti-spike antibodies despite three or more vaccine doses, but this proportion decreases with sequential booster doses. Choice of immunosuppressant and disease type is strongly associated with serological response. Antibody testing using lateral flow immunoassay tests could enable rapid identification of individuals who are most likely to benefit from additional COVID-19 interventions. FUNDING: UK Research and Innovation, Kidney Research UK, Blood Cancer UK, Vasculitis UK and the Cystic Fibrosis Trust.

The TREATT Trial (TRial to EvaluAte Tranexamic acid therapy in Thrombocytopenia): safety and efficacy of tranexamic acid in patients with haematological malignancies with severe thrombocytopenia: study protocol for a double-blind randomised controlled trial.

BACKGROUND: Patients with haematological malignancies often develop thrombocytopenia as a consequence of either their disease or its treatment. Platelet transfusions are commonly given to raise a low platelet count and reduce the risk of clinical bleeding (prophylaxis) or stop active bleeding (therapy). Recent studies have shown that many patients continue to experience bleeding despite the use of prophylactic platelet transfusions. Tranexamic acid is an anti-fibrinolytic, which reduces the breakdown of clots formed in response to bleeding. Anti-fibrinolytics have been shown to prevent bleeding, decrease blood loss and use of red cell transfusions in elective and emergency surgery, and are used widely in these settings. The aim of this trial is to test whether giving tranexamic acid to patients receiving treatment for haematological malignancies reduces the risk of bleeding or death and the need for platelet transfusions. METHODS: This is a multinational randomised, double-blind, placebo-controlled, parallel, superiority trial. Patients will be randomly assigned to receive tranexamic acid (given intravenously or orally) or a matching placebo in a 1:1 ratio, stratified by site. Patients with haematological malignancies receiving intensive chemotherapy or stem cell transplantation (or both) who are at least 18 years of age and expected to become severely thrombocytopenic for at least 5 days will be eligible for this trial. The primary outcome of the trial is the proportion of patients who died or had bleeding of World Health Organization grade 2 or above during the first 30 days of the trial. We will measure the rates of bleeding daily by using a short, structured assessment of bleeding, and we will record the number of transfusions given to patients. We will assess the risk of arterial and venous thrombosis for 120 days from the start of trial treatment. DISCUSSION: This trial will assess the safety and efficacy of using prophylactic tranexamic acid during a period of intensive chemotherapy and associated thrombocytopenia in people with haematological disorders. TRIAL REGISTRATION: This study was prospectively registered on Current Controlled Trials on 25 March 2015 (ISRCTN73545489) and is also registered on ClinicalTrials.gov (NCT03136445).

Clinical bleeding and thrombin generation in admissions to critical care with prolonged prothrombin time: an exploratory study.

BACKGROUND: Prolongation of prothrombin time (PT) is often recorded in critical illness, but has limited ability to predict risk of bleeding. This exploratory study was aimed at assessing a role for thrombin generation (TG) to predict bleeding. STUDY DESIGN AND METHODS: TG was measured by calibrated automated thrombography in admissions to intensive care with prolonged PT. Bleeding events were recorded up to Day 5 after enrollment and correlated with results of PT ratio (PTR) and variables of TG. RESULTS: A total of 306 patients were recruited. A total of 101 bleeding events developed in 46 patients during the period of observation. Many patients with prolonged PT had endogenous thrombin potential (ETP), which was within the normal range (120/251 patients, 47.8%) or even elevated (8%). Although some patients had a reduction in ETP or peak thrombin, these were present over a wide range of PTR. There was no suggestion by receiver operating characteristic analysis that variables of conventional TG were sensitive at predicting bleeding. No bleeding events were documented in patients defined as ETP high, despite elevated PTR. CONCLUSION: Future studies need to explore a role for alternatives tests of coagulation in critical illness. Development of TG assays is required to positively identify more patients at increased bleeding risk or to exclude a larger number at low risk and how this relates to subgroups, such as patients with liver disease, and the need for prophylactic plasma transfusion.

Nurses' role in platelet transfusion clinical trials.

This article describes the crucial role of research nurses in studies coordinated by the NHS Blood and Transplant Clinical Trials Unit (CTU), using two recent trials studying platelet transfusions in adults and neonates as examples. CTU studies are coordinated by trial managers, most of whom are or were registered nurses, which supports relationships with research nurses in participating hospitals. During trials the CTU sustains research nurses with ongoing education and training, and establishes cooperative working between nurses and the unit, and between nurses in different locations. Regular feedback from research nurses guides the design and management of clinical trials.

Prospective observational cohort study of the association between thromboelastometry, coagulation and platelet parameters and bleeding in patients with haematological malignancies- the ATHENA study.

Previous studies have shown that total platelet count (TPC) inadequately predicts bleeding in thrombocytopenic patients with haematological malignancies. This prospective cohort study evaluated whether rotational thromboelastometry (ROTEM), coagulation or other platelet parameters were more strongly associated with bleeding than TPC. Adults treated at two UK haematology centres for haematological malignancy were enrolled if they had thrombocytopenia (TPC ≤ 50 × 10(9) /l) at beginning of, or during treatment (International Standard Randomized Controlled Trial Number 81226121). TPC and bleeding symptoms were recorded daily for up to 30 d or until platelet count recovery, hospital discharge or death. Blood samples were tested thrice weekly using ROTEM, Platelet Function Analyser (PFA)-100(®) , coagulation and platelet cytometry assays. Bleeding symptoms and TPC from 49/50 enrolled participants who completed the study were recorded on 754/760 study days. Mean platelet volume and PFA-100(®) closure times were frequently inestimatable because of thrombocytopenia. TPC, absolute immature platelet number (AIPN) and ROTEM maximum clot firmness were significantly associated with bleeding on the day after blood sampling. Only AIPN was associated with bleeding after adjustment of test results for TPC (Odds Ratio 0·52, 95% confidence interval 0·28-0·97; P = 0·038). In a predictive model, AIPN was superior to TPC for predicting bleeding. This study indicates that AIPN may be more clinically useful than TPC at predicting bleeding.

A no-prophylaxis platelet-transfusion strategy for hematologic cancers.

BACKGROUND: The effectiveness of platelet transfusions to prevent bleeding in patients with hematologic cancers remains unclear. This trial assessed whether a policy of not giving prophylactic platelet transfusions was as effective and safe as a policy of providing prophylaxis. METHODS: We conducted this randomized, open-label, noninferiority trial at 14 centers in the United Kingdom and Australia. Patients were randomly assigned to receive, or not to receive, prophylactic platelet transfusions when morning platelet counts were less than 10×10(9) per liter. Eligible patients were persons 16 years of age or older who were receiving chemotherapy or undergoing stem-cell transplantation and who had or were expected to have thrombocytopenia. The primary end point was bleeding of World Health Organization (WHO) grade 2, 3, or 4 up to 30 days after randomization. RESULTS: A total of 600 patients (301 in the no-prophylaxis group and 299 in the prophylaxis group) underwent randomization between 2006 and 2011. Bleeding of WHO grade 2, 3, or 4 occurred in 151 of 300 patients (50%) in the no-prophylaxis group, as compared with 128 of 298 (43%) in the prophylaxis group (adjusted difference in proportions, 8.4 percentage points; 90% confidence interval, 1.7 to 15.2; P=0.06 for noninferiority). Patients in the no-prophylaxis group had more days with bleeding and a shorter time to the first bleeding episode than did patients in the prophylaxis group. Platelet use was markedly reduced in the no-prophylaxis group. A prespecified subgroup analysis identified similar rates of bleeding in the two study groups among patients undergoing autologous stem-cell transplantation. CONCLUSIONS: The results of our study support the need for the continued use of prophylaxis with platelet transfusion and show the benefit of such prophylaxis for reducing bleeding, as compared with no prophylaxis. A significant number of patients had bleeding despite prophylaxis. (Funded by the National Health Service Blood and Transplant Research and Development Committee and the Australian Red Cross Blood Service; TOPPS Controlled-Trials.com number, ISRCTN08758735.).

Do all patients with hematologic malignancies and severe thrombocytopenia need prophylactic platelet transfusions? Background, rationale, and design of a clinical trial (trial of platelet prophylaxis) to assess the effectiveness of prophylactic platelet transfusions.

Although considerable advances have been made in many aspects of platelet transfusion therapy in the last 30 years, some areas continue to provoke debate, including the use of prophylactic platelet transfusions for the prevention of thrombocytopenic bleeding in patients with bone marrow failure. We have designed a randomized controlled trial to compare prophylactic platelet use with a threshold of a platelet count of 10 x 10(9)/L with no prophylaxis in adult thrombocytopenic patients with hematologic malignancies. The trial question is whether a no-prophylactic policy for the use of platelet transfusions in patients with hematologic malignancies is not inferior to a threshold prophylactic policy at 10 x 10(9)/L, for bleeding at World Health Organization (WHO) grade 2, 3, or 4, up to 30 days from randomization. The primary outcome measure is the proportion of patients who have a significant clinical bleed, defined as WHO grade 2 or higher up to 30 days from randomization. Subsidiary clinical outcome measures include time to first bleed and a descriptive analysis of all severe bleeds. A bleeding assessment form is completed daily for all study subjects until day 30 from randomization. Minor modifications were made to the definitions at WHO grades 1 and 2 for petechiae and duration of nose bleeds, after piloting of the bleeding assessment forms. This study has been designed as a 2-stage randomized trial with an interim analysis planned after a minimum of 100 patients had been randomized and had completed their period of observation. Patients have initially been enrolled through 3 United Kingdom hematology centers. The interim analysis has been completed, and the results have confirmed a final sample size of 600 patients. Recruitment is now being extended to other centers in United Kingdom and Australia. Local research nurses are not blinded to treatment allocation, but a number of measures to reduce risk of assessment bias include repeated education around standard operating procedures, common definitions, and duplication of assessments. The expected completion date for the 5-year study is December 2011.