The Health Information and Quality Authority has today (27 July 2011) published the results of a health technology assessment (HTA) of prion filters, a new technology with the potential to further reduce the low risk of transmitting variant-Creutzfeldt-Jakob disease (vCJD) through a blood transfusion.

The Authority’s assessment found that, based on current published evidence, the filters appear to be safe and would remove almost all the residual risk of vCJD transmission from red cell concentrates (blood from which most of the plasma and platelets has been removed). However, introduction of prion filters, either for all transfusion recipients or for limited sub-groups, was found to be not cost-effective when measured against traditional standards of cost-effectiveness.

vCJD is one of a group of rare, progressive and ultimately fatal degenerative disease of the nervous system, also known as prion diseases. They are thought to be caused by an abnormal form of a naturally occurring protein in the brain (the prion protein) that has been acquired through infection. The origin of vCJD has been linked to the consumption of BSE-infected beef.  However, vCJD may also be transmitted via a blood transfusion from an infected donor who has not developed symptoms of the disease. Prion filtration is a new technology to be used in conjunction with existing blood safety strategies which aim to reduce the risk of vCJD transmission. The filters are designed to remove infectious prion protein from donated blood rendering the transfused blood safer to recipients.

The assessment notes the substantial uncertainty around the risk of vCJD transmission in Ireland. It notes the level of undiagnosed vCJD in Ireland is likely to be low and that the corresponding risk of transfusion-transmitted infection would be extremely low.

Dr Patricia Harrington, Head of Assessment with the Authority’s Health Technology Assessment Directorate, said: “The Authority’s HTA found that to filter red cell concentrates as proposed by the blood service would initially cost €11 million per year. It was estimated that such a measure would, over a 10-year period, potentially prevent two deaths from vCJD.”

The Board of the Authority has approved the HTA report and it has been submitted to the Minister for Health for his consideration.

Dr Harrington concluded: “The HTA has concluded that the cost of universal prion filtration is substantial. This financial cost, of further minimising what is most likely a low risk, is high compared to the likely benefits. In Ireland, the risk of acquiring vCJD from a transfusion of red cell concentrates in the absence of prion filtration is low. It notes therefore, that in the context of a finite healthcare budget, a decision to invest in prion filtration may have implications for the funding of other technologies and services in our health system.”

Further Information: 

Marty Whelan
Head of Communications and Stakeholder Engagement Directorate
01 8147481 / 086 2447623 or email mwhelan@hiqa.ie

Notes to the Editor: 

• The Health Information and Quality Authority is the statutory organisation in Ireland with a responsibility to carry out national health technology assessments (HTAs) and to develop guidelines for the conduct of HTAs across our health system.
•  Whole donated blood is not generally re-transfused to recipients. It is first separated into its constituent parts, including units of red blood cells (referred to as units or red cell concentrates or RCC), units of platelets and units of plasma. The term ‘blood transfusion’ typically refers to a transfusion of RCC.
• Prion filters are new technologies that aim to reduce any residual infectious prion protein that may be present in donated blood, rendering it safer for transfusion. The IBTS has proposed adoption of prion filtration of RCC as an additional safety control measure.
• There is currently no commercially available human blood test to identify the presence of the abnormal prionprotein associated with vCJD.
• The origin of vCJD has been linked to the consumption of BSE-infected beef.  The incidence of BSE and vCJDpeaked in the UK in 1992-1993 and 2000, respectively, declining since. There have been 170 deaths from vCJD in the UK and 4 deaths in Ireland, two of which are thought to have originated in the UK.
• vCJD may potentially be transmitted via a blood transfusion from an infected donor who may not have developed symptoms of the disease. Worldwide there have been five documented cases of transfusion-related vCJD infection, resulting in three deaths from clinical vCJD.
•  It is predicted that prion filtration of all RCCs will initially cost €11 million per annum and, over a 10-year time period, will prevent two deaths from vCJD and result in 19.4 discounted life years gained. The incremental cost-effectiveness ratio (ICER) of prion filtration is €2.6 million per quality of life year gained (QALY). As a comparison, a HTA of population-based colorectal cancer screening carried out by the Authority found that this measure had an estimated ICER of €1,696 per QALY compared to a policy of no screening. This screening was estimated to cost €15 million per annum at full implementation, averting 160 cases of colorectal cancer and 270 deaths from colorectal cancer in year 10 of the screening programme.