Drug-induced thrombotic thrombocytopenic purpura: A systematic review and review of European and North American pharmacovigilance data.

Many medications have been reported to be associated with thrombotic thrombocytopenic purpura (TTP) through pharmacovigilance data and published case reports. Whilst there are existing data available regarding drug-induced thrombotic microangiopathy, there is no available synthesis of evidence to assess drug-induced TTP (DI-TTP). Despite this lack of evidence, patients with TTP are often advised against using many medications due to the theoretical risk of DI-TTP. This systematic review evaluated the evidence for an association of medications reported as potential triggers for TTP. Of 5098 records available 261 articles were assessed further for eligibility. Fifty-seven reports, totalling 90 patients, were included in the final analysis. There were no cases where the level of association was rated as definite or probable, demonstrating a lack of evidence of any drug causing DI-TTP. This paucity of evidence was also demonstrated in the pharmacovigilance data, where 613 drugs were reported as potential causes of TTP without assessment of the strength of association. This systematic review demonstrates the need for standardised reporting of potential drugs causing TTP. Many reports omit basic information and, therefore, hinder the chance of finding a causative link if one exists.

COVID-19-related adrenal haemorrhage: Multicentre UK experience and systematic review of the literature.

OBJECTIVE: Adrenal haemorrhage (AH) is an uncommon, usually incidental imaging finding in acutely unwell patients. AH has been reported during coronavirus disease 2019 (COVID-19) infection and following ChAdOx1 nCoV-19 (Oxford-AstraZeneca) vaccination. The Society for Endocrinology (SfE) established a task force to describe the UK experience of COVID-19-related AH. DESIGN: A systematic literature review was undertaken. A survey was conducted through the SfE clinical membership to identify patients with COVID-19-related AH using a standardized data collection tool. RESULTS: The literature search yielded 25 cases of COVID-19-related AH (19 bilateral; 13 infection-related, and 12 vaccine-related). Eight UK centres responded to the survey with at least one case. A total of 18 cases were included in the descriptive study, including 11 from the survey and 7 UK-based patients from the systematic review. Seven patients (4 males; median age 53 (range 26-70) years), had infection-related AH (four bilateral). Median time from positive COVID-19 test to AH detection was 8 (range 1-30) days. Eleven cases of vaccine-related AH (eight bilateral) were captured (3 males; median age 47 (range 23-78) years). Median time between vaccination (nine Oxford-AstraZeneca and two Pfizer-BioNTech) and AH was 9 (range 2-27) days; 9/11 AH occurred after the first vaccine dose. Acute abdominal pain was the commonest presentation (72%) in AH of any cause. All 12 patients with bilateral AH and one patient with unilateral AH required glucocorticoid replacement. CONCLUSION: Adrenal haemorrhage with consequential adrenal insufficiency can be a complication of COVID-19 infection and vaccination. Adrenal function assessment is mandatory to avoid the potentially fatal consequences of unrecognized adrenal insufficiency.

Kidney Transplantation From Deceased Donors With Vaccine-induced Immune Thrombocytopenia and Thrombosis: An Updated Analysis of the UK Experience.

BACKGROUND: The emergence and attendant mortality of vaccine-induced immune thrombocytopenia and thrombosis (VITT) as a consequence of vaccination against severe acute respiratory syndrome coronavirus 2 have resulted in some patients with VITT being considered as deceased organ donors. Outcomes after kidney transplantation in this context are poorly described. Because the disease seems to be mediated by antiplatelet factor 4 antibodies, there is a theoretical risk of transmission via passenger leukocytes within the allograft. METHODS: We analyzed the experience of kidney transplantation from donors with VITT in the United Kingdom between January and June 2021. We followed-up all recipients of kidney-only transplants from donors with VITT to detect major postoperative complications or features of disease transmission and assess graft survival and function. RESULTS: There were 16 kidney donors and 30 single kidney transplant recipients in our study period. Of 11 preimplantation biopsies, 4 showed widespread glomerular microthrombi. After a median of 5 mo, patient and graft survival were 97% and 90%, respectively. The median 3-mo estimated glomerular filtration rate was 51 mL/min/1.73 m 2 . Two recipients had detectable antiplatelet factor 4 antibodies but no evidence of clinical disease after transplantation. Major hemorrhagic complications occurred in 3 recipients, all of whom had independent risk factors for bleeding, resulting in the loss of 2 grafts. The involvement of VITT could not be completely excluded in one of these cases. CONCLUSIONS: The UK experience to date shows that favorable outcomes are possible after kidney transplantation from donors with VITT but highlights the need for ongoing vigilance for donor-related complications in these patients.

A case of ChAdOx1 vaccine-induced thrombocytopenia and thrombosis syndrome leading to bilateral adrenal haemorrhage and adrenal insufficiency.

Summary: Vaccine-induced thrombosis and thrombocytopenia (VITT) after vaccination against SARS-CoV-2 with the adenoviral vector-based vaccines ChAdOx1 and Ad26.COV2.S has been associated with adrenal pathology, such as bilateral adrenal vein thrombosis, adrenal cortex haemorrhage and adrenal insufficiency in 6% of patients. We report the case of a 23-year-old woman who presented at 8 days after ChAdOx1 vaccination with a low platelet count of 43 × 109/L, raised d dimers >100 000 ng/mL and multiple lobar and segmental pulmonary emboli. Anti-platelet factor 4 antibodies were detected confirming definite VITT in accordance with the UK diagneostic criteria. At 16 days post-vaccine, further imaging showed bilateral adrenal haemorrhage, non-occlusive splenic vein thrombosis and right ventricular thrombosis. Her cortisol level was <25 nmol/L. She was treated with anticoagulation, plasmapheresis, immunosuppression and steroid replacement. She had high anti-spike titre and positive anti-nucleocapsid titres for SARS-CoV-2. She developed seizures secondary to posterior reversible encephalopathy, requiring intensive care. After 4 weeks in hospital, she was discharged on warfarin, hydrocortisone and fludrocortisone replacement. Short synacthen tests 3 and 9 months later showed no recovery of adrenal function, although magnetic resonance imaging of the adrenal glands showed resolving adrenal haemorrhage. Adrenal insufficiency secondary to bilateral adrenal vein thrombosis and adrenal haemorrhage should be suspected in patients with VITT and treated promptly. Adrenal vein thrombosis can occur either as the initial presentation of VITT or days to weeks after the development of thrombosis in other sites. Further studies are required to provide insight on adrenal function recovery after VITT. Learning points: Adrenal insufficiency secondary to bilateral adrenal vein thrombosis and adrenal cortex haemorrhage should be suspected in patients with vaccine-induced thrombosis and thrombocytopenia (VITT) and treated promptly. Adrenal vein thrombosis can occur as the initial presentation of VITT or even days to weeks later after the development of thrombosis in other more classic sites (e.g. pulmonary or cerebral vasculature). Completion of vaccination schedule against SARS-CoV-2 post-VITT using an mRNA-based vaccine should be recommended to patients post-VITT as mRNA-based vaccines have not been associated with VITT but confer protection against SARS-CoV-2. There is paucity of data regarding the potential for recovery of adrenal function after bilateral adrenal haemorrhage in the context of VITT, and thus, more studies are needed to inform clinical practice. The need for disease registries for rare conditions, such as VITT, is crucial as direct cooperation and sharing of information by clinicians might enable quicker identification of disease patterns than would have been possible via established reporting tools of adverse events.

Natural history of PF4 antibodies in vaccine-induced immune thrombocytopenia and thrombosis.

The COVID-19 pandemic has resulted in the rapid development of a range of vaccines against SARS-CoV-2. Vaccine-induced immune thrombocytopenia and thrombosis (VITT) is a rare but life-threatening complication of primarily adenoviral-based vaccines associated with the presence of antibodies to a PF4/polyanion neoepitope and measured by using enzyme-linked immunosorbent assays. Presented are serial anti-PF4/polyanion antibody, platelet, and D-dimer measurements in a large cohort of patients and their relation to relapse. Overall, 51% of patients using the Stago assay had persistently positive anti-PF4/polyanion levels 100 days' postdiagnosis, whereas 94% of patients monitored by using the Immucor assay remain positive. The median duration of positivity of the PF4 assay is 87 days, with 72% of patients remaining positive after a median follow-up of 105 days. The use of plasma exchange seemed to reduce anti-PF4/polyanion levels and increase platelet counts in the acute setting more rapidly than other therapies. The rate of relapse in this study was 12.6%, with all relapsed cases exhibiting persistently positive PF4 antibodies and falling platelet counts. Only one patient had extension of their thrombosis. Overall, despite the persistence of PF4 antibodies in 72% of patients, the rate of relapse was low and did not seem to result in recrudescence of the aggressive clinical picture seen at index presentation. Monitoring of these patients in the UK cohort is ongoing and will aid in definition of the natural history of this novel condition.

The psychiatric and psychological sequelae of vaccine-induced immune thrombotic thrombocytopenia (VITT).

This review paper explores the potential psychiatric and psychological sequelae of vaccine-induced immune thrombotic thrombocytopenia, also called vaccine-induced immune thrombocytopenia, and thrombosis (VITT). In the absence of any literature to date we have extrapolated data from similar conditions, particularly data pertaining to the critical care population. We discuss both the direct and indirect effects of thrombosis, likely psychiatric and psychological challenges during recovery, and ethical issues around vaccination. We have also suggested a comprehensive guide to the psychiatric assessment and management of patients presenting with VITT with the aim of early identification of problems and maximizing rehabilitation potential and quality of life.

Clinical picture of VITT.

This chapter explores the clinical features of vaccine-induced immune thrombotic thrombocytopenia, also called vaccine-induced immune thrombocytopenia and thrombosis (VITT). Whilst the etiology is distinct from other causes of thrombotic thrombocytopenia syndrome (TTS), presentation may be similar and hence the need for strict diagnostic criteria to ensure accurate and prompt diagnosis and early treatment. Studies have identified prognostic markers of the disease, directing therapy and management pathways, and mortality and morbidity from this rare but life-threatening and potentially disabling consequence of the ChAdOx1 nCov-19 vaccine has declined.

Vaccine-induced immune thrombotic thrombocytopenia (VITT): Update on diagnosis and management considering different resources.

Vaccine-induced immune thrombotic thrombocytopenia (VITT) is a rare but severe immunological reaction to the non-replicable adenoviral vector-based COVID-19 vaccines. Extreme activation of platelets and the coagulation system leads to a high risk of death from venous or arterial thrombosis or secondary hemorrhage. Public and clinician awareness has reduced mortality of VITT by nearly 90%. The World Health Organization provided a guideline in July 2021 on diagnosis and management of VITT (also called thrombosis with thrombocytopenia syndrome, or TTS). Since July 2021, new, clinically relevant information has become available. This update has been summarized by the authors in an informal process with recommendations for low resource environments. We provide new available evidence on VITT to empower clinicians to recognize VITT early, then effectively diagnose and treat the disorder to reduce morbidity and mortality. We strongly encourage production of clear management pathways for primary care settings and hospital settings.

VITT, COVID-19 and the Expert Haematology Panel: The story of how the UK responded to emerging cases of vaccine-induced immune thrombocytopenia and thrombosis during the vaccination programme.

The COVID-19 pandemic has resulted in the development of highly effective vaccines that provide hope to the global community for reducing the spread of SARS-CoV-2 and limiting the mortality and morbidity caused by the disease. These vaccines have been produced using differing technologies, taken through clinical trials, and rolled out across the UK at unprecedented speed. However, the recent emergence of rare cases of life-threatening thrombosis in association with thrombocytopenia has threatened to derail one particular vaccine, the Oxford AstraZeneca ChAdOx1 vaccine, upon which many countries are dependent for their vaccination programmes. The story of how this situation has been managed in the UK at the height of the vaccine roll-out represents a remarkable collective endeavour on the part of the haematology community, working closely with other acute medical and surgical professionals within the NHS and the UK health regulatory bodies, to provide rapid expert guidance that has saved lives and helped keep the national vaccination programme on track.

A real-world study of immune thrombocytopenia management during the COVID-19 pandemic in the UK.

The COVID-19 pandemic has created many challenges in the management of immune thrombocytopenic purpura (ITP). The recommendation for avoidance of steroids by WHO led to the off-licence use, supported by NHS England, of thrombopoietin mimetics (TPO-RA) for newly diagnosed or relapsed ITP. This is a real-world prospective study which investigated the treatment patterns and outcomes in this setting. Twenty-four hospitals across the UK submitted 343 cases. Corticosteroids remain the mainstay of ITP treatment, but TPO-RAs were more effective. Incidental COVID-19 infection was identified in a significant number of patients (9·5%), while 14 cases were thought to be secondary to COVID-19 vaccination.

Clinical Features of Vaccine-Induced Immune Thrombocytopenia and Thrombosis.

BACKGROUND: Vaccine-induced immune thrombocytopenia and thrombosis (VITT) is a new syndrome associated with the ChAdOx1 nCoV-19 adenoviral vector vaccine against severe acute respiratory syndrome coronavirus 2. Data are lacking on the clinical features of and the prognostic criteria for this disorder. METHODS: We conducted a prospective cohort study involving patients with suspected VITT who presented to hospitals in the United Kingdom between March 22 and June 6, 2021. Data were collected with the use of an anonymized electronic form, and cases were identified as definite or probable VITT according to prespecified criteria. Baseline characteristics and clinicopathological features of the patients, risk factors, treatment, and markers of poor prognosis were determined. RESULTS: Among 294 patients who were evaluated, we identified 170 definite and 50 probable cases of VITT. All the patients had received the first dose of ChAdOx1 nCoV-19 vaccine and presented 5 to 48 days (median, 14) after vaccination. The age range was 18 to 79 years (median, 48), with no sex preponderance and no identifiable medical risk factors. Overall mortality was 22%. The odds of death increased by a factor of 2.7 (95% confidence interval [CI], 1.4 to 5.2) among patients with cerebral venous sinus thrombosis, by a factor of 1.7 (95% CI, 1.3 to 2.3) for every 50% decrease in the baseline platelet count, by a factor of 1.2 (95% CI, 1.0 to 1.3) for every increase of 10,000 fibrinogen-equivalent units in the baseline d-dimer level, and by a factor of 1.7 (95% CI, 1.1 to 2.5) for every 50% decrease in the baseline fibrinogen level. Multivariate analysis identified the baseline platelet count and the presence of intracranial hemorrhage as being independently associated with death; the observed mortality was 73% among patients with platelet counts below 30,000 per cubic millimeter and intracranial hemorrhage. CONCLUSIONS: The high mortality associated with VITT was highest among patients with a low platelet count and intracranial hemorrhage. Treatment remains uncertain, but identification of prognostic markers may help guide effective management. (Funded by the Oxford University Hospitals NHS Foundation Trust.).