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Blood plasma from UK and Irish donors when assessed for Creutzfeldt–Jakob disease infectivity
This is a summary of a supplementary memorandum prepared for the European Medicines Agency by United Kingdom Plasma Action in collaboration with the UK Primary Immunodeficiency Network, the British Society for Immunology, the Immunology & Allergy Nurse Group.
Blood donations are used to isolate plasma medicines which help provide lifesaving and life-enhancing medicines for NHS patients.1 Plasma donations are particularly in demand for the manufacture of immunoglobulins and the SARS-CoV-2 pandemic has led to new questions about the benefits of plasma-derived medicines.2
In 1998, concern about the risk of contracting variant Creutzfeldt–Jakob disease (vCJD) from UK blood donors led to a ban on UK-sourced blood plasma being imposed by the UK Government. In 2021, the UK Department of Health and Social Care lifted this ban on expert recommendation, following a review of the evidence conducted by the Medicines and Healthcare products Regulatory Agency (MHRA), that UK blood plasma is safe for clinical use.2
Although it has always been known that pathogens and toxins can be transmitted through blood, purification methods mostly eliminated this concern. However, prions associated with vCJD remained a risk and no test was available at the time to detect the relevant prion protein in purified plasma. This remained the case into the 21st century.3,4
Significant programmes were launched to examine prion removal processes with promising results reported in five publications.5–9 Despite this, no satisfactory test for vCJD was ever developed to the point of commercialisation and deemed accurate enough for widespread use. However, in October 1999, the practice of leucodepletion was introduced in the UK at the time and remains a major precaution to protect the blood supply.10
Despite caution, a 2011 study followed 787 patients who were exposed to a vCJD implicated blood plasma batch. Overall, 604 (77%) were followed up for over 13 years and 94 patients (16%) had received implicated batches linked to donors who developed clinical vCJD within 6 months of their donations. By 1st January 2009, none of these patients had developed clinical vCJD.11
Another UK National CJD Surveillance Centre long-term study monitored a cohort of patients on regular immunoglobulin treatment dating from 1996. This study also included patients who received plasma batches from donors who were subsequently revealed to be vCJD positive. Despite this, the study has so far reported no cases of vCJD infection, confirmed or suspected, after 24 years of closely monitoring the recipients.12 This, along with scientific opinions from other experts, has supported the conclusion that blood donated by UK donors is safe when assessed for vCJD infectivity risk and has informed the decision to lift the ban in 2021.2
In 2021, the UK Department of Health and Social Care lifted the ban on blood plasma from UK donors following the recommendation from experts that blood plasma treatments are safe.2 {in respect to vCJD compared to risk globally}
References
- NHS Blood and Transplant. Convalescent plasma programme. Available at: https://www.nhsbt.nhs.uk/covid-19-research/plasma-programme/. Accessed February 2022.
- Gov UK. Ban lifted to allow UK blood plasma to be used for life-saving treatments. Available at: https://www.gov.uk/government/news/ban-lifted-to-allow-uk-blood-plasma-to-be-used-for-life-saving-treatments. Accessed February 2022.
- Gov UK. Critical risk assessment report: use of UK plasma for the manufacture of immunoglobulins and vCJD risk. Available at: https://www.gov.uk/government/publications/critical-risk-assessment-report-use-of-uk-plasma-for-the-manufacture-of-immunoglobulins-and-vcjd-risk/critical-risk-assessment-report-use-of-uk-plasma-for-the-manufacture-of-immunoglobulins-and-vcjd-risk. Accessed February 2022.
- European Medicines Agency. CHMP position statement on Creutzfeldt-Jakob disease and plasma-derived and urine-derived medicinal products. Available at: https://www.ema.europa.eu/en/documents/scientific-guideline/chmp-position-statement-creutzfeldt-jacob-disease-plasma-derived-urine-derived-medicinal-products_en.pdf. Accessed February 2022.
- Foster PR, et al. Studies on the removal of abnormal prion protein by processes used in the manufacture of human plasma products. Vox Sang 2000;78:86–95.
- Reichl HE et al. Studies on the removal of a bovine spongiform encephalopathy-derived agent by processes used in the manufacture of human immunoglobulin. Vox Sang 2000;83:137–45.
- Foster PR et al. Distribution of a bovine spongiform encephalopathy-derived agent over ion-exchange chromatography used in the preparation of concentrates of fibrinogen and factor VIII. Vox Sang 2004;86:92–9.
- Roberts PL et al. Removal of TSE agent from plasma products manufactured in the United Kingdom. Vox Sang 2013;104:299–308.
- Roberts PL et al. Development of an intravenous immunoglobulin with improved safety and functional activity. Biologicals 2015;43;123–9.
- Advisory Committee on the Safety of Blood, Tissues and Organs. Measures currently in place in the UK to reduce the potential risk of transmitting variant Creutzfeldt-Jakob disease via blood. Available at: https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/407681/measures-vcjd.pdf. Accessed February 2022.
- Zaman SM et al. The risk of variant Creutzfeldt-Jakob disease among UK patients with bleeding disorders, known to have received potentially contaminated plasma products. Haemophilia 2011;17:931–7.
- The National CJD Research & Surveillance Unit. Prion surveillance in primary immunodeficiency patients. Available at: https://www.cjd.ed.ac.uk/projects/prion-surveillance-primary-immunodeficiency-patients. Accessed February 2022.
