Independent report

SaBTO: Advisory Committee on the Safety of Blood, Tissues and Organs annual report 2017 to 2018

Published 6 September 2019

The report covers the:

• 31st meeting of SaBTO on 9 June 2017
• 32nd meeting of SaBTO on 20 September 2017
• 33rd meeting of SaBTO on 17 January 2018
• activities of working parties

Topics considered by registered practitioners in 2017 to 2018

Blood

Donor selection criteria review

The SaBTO donor selection criteria review was completed and the report published on the SaBTO website.

The review had looked at the donor selection criteria for various behaviours which were considered to increase the likelihood of contracting viruses such as human immunodeficiency virus (HIV), hepatitis B virus (HBV), hepatitis C virus (HCV) and syphilis, which could then be transmitted to recipients of blood transfusions or tissue and gamete transplantation. These behaviours included skin piercing and tattoos, endoscopy, acupuncture, injection of non-prescription drugs, commercial sex work and men who have sex with men.

The recommendations for donor selection were based on the risk of transmission. For example, skin piercing, acupuncture and endoscopy were considered low risk if carried out in the UK so no deferral period was recommended. For behaviours where there was a higher risk of transmission, donors would be deferred for 3 months. This recommended period was based on twice the window period – the period when transmission of the virus is possible but the amount of virus in the blood is too low to be detected by screening. The window period of HBV was selected as this was the longest window period of the blood-borne viruses being considered.

These selection criteria produced significant changes for donation by commercial sex workers who previously had a permanent deferral and for men who had sex with men, with a reduction of deferral from 12 months to 3 months.

The selection criteria for persons who had injected prescription drugs was reduced from permanent deferral to 12 months. This period reflected evidence that drug users are more likely to relapse in the first few months so are still high risk.

Of note, all the recommendations were evidence-based but some would require changes to EU Blood and Tissue directives and/or UK regulations before they could be implemented.

Importation of plasma and platelet apheresis as risk reduction measures for variant Creutzfeldt-Jakob disease (vCJD)

A working group, led by Dr Stephen Thomas, was established to look at the continued importation of plasma from outside the UK and provision of platelets collected by apheresis as a risk reduction measure for vCJD. Currently, plasma is imported for:

• individuals born on or after 1 January 1996 (this date was determined as the cut-off for exposure to meat from cows with bovine spongiform encephalopathy, the animal form of vCJD)
• individuals with thrombotic thrombocytopenia purpura (TTP) who receive large volumes of plasma for their treatment

Similarly, single donor apheresis platelets are provided for individuals born after 1 January 1996 rather than pooled platelets as this reduces exposure to preparations from multiple donors. However:

• there had been far fewer transmissions of vCJD from blood than had been anticipated when these measures were first implemented
• the number of individuals born after 1995 continued to rise
• there were potential issues with supply
• hospitals providing adult services had to maintain a dual inventory of imported and UK sourced plasma for patient

Furthermore, the risk of nvCJD will be reduced by the use of leucodepletion.

As the Advisory Committee on Dangerous Pathogens (ACDP) was in the process of revising the blood safety risk assessment, which was expected to lower the expected number of future vCJD transmissions from blood and blood components, it was proposed that this was a good time to conduct a review of maintaining these measures.

The working group will:

• use the ACDP blood safety risk assessment to estimate the risk of vCJD from UK plasma
• survey and consult paediatric hospitals and trauma centres on existing practice and operational issues
• examine the health economics of continuing to maintain these measures

Patient groups will be consulted on any provisional recommendations.

Organs, tissues and cells

Donor selection criteria review

The donor selection review recommended, where relevant, similar changes to selection criteria for tissues and cells as for blood. Organs were not within the scope of the review.

It was recognised that the legislation for tissues and cells was less proscriptive than for blood and individual risk assessments could be conducted to better determine the risk if a donation was urgent or rare.

SaBTO working groups

Donor Organ Risk Assessment (DORA) working group

James Powell had stepped down from the co-chair of DORA and the existing workplan had been largely completed. Members agreed a new workplan, with Dr Rachel Hilton as co-chair to look at guidelines on the use of organs from donors with cancer and metabolic diseases as well as donors with unusual anatomical variants and donors who had been exposed to potentially toxic agents.

Microbiological Safety of Human Organs, Tissues and Cells Guideline Review working group update

The revised microbiological safety guidelines were completed and published on the SaBTO website together with a summary of significant changes.

Membership 2017 to 2018

• James Neuberger (Chair)
• Richard Seton Tedder
• Gail Miflin
• Alison Murdoch
• Paul Alexandre De Sousa
• Gill Hollis
• Richard Knight
• James Powell
• Stephen Thomas
• Susan Brailsford
• Lynn Manson
• Rachel Hilton
• Charles Newstead
• Akila Chandrasekar
• Will Irving