PL04 Tissue Retrieval and Processing Initiatives to Reduce the Risk of vCJD Transmission

Abstract

Risk reduction concerning potential tissue allograft vCJD transmission starts with effective donor selection and screening measures. Even as tests are developed and introduced, there are still risks regarding window period, which may result in potentially infective units being transplanted. Methodology can be implemented to reduce this risk by attempting to remove the infectious agents. NBS introduced blood leucodepletion as a risk reduction measure. For many highly processed tissue products, this is already achieved by washing blood and marrow from the graft. However the bone graft of preference for UK orthopaedic surgeons is fresh frozen femoral heads (containing blood/marrow) which have not been irradiated to 25 kGy. NBS have developed a bone washing protocol to achieve >99% marrow and blood depletion and are assessing whether the irradiation dose can be reduced as a result of bioreduction events included in the process. This is achieved without pooling tissues from multiple donors in turn reducing recipient exposure. Clinicians may find this a suitable alternative risk‐reduced product. Other initiatives have been introduced to reduce the risk of abnormal PrP contamination of equipment, in turn cascading to subsequent grafts. Disposable equipment is now used wherever possible. Where not possible (e.g. bone saws, skin dermatomes etc.) the equipment is washed and sterilized to best practice (HTM2010 and HTM2030), is fully traced through subsequent graft exposures, and when a suitable screen test is performed, kit is quarantined until a negative result is received.