An archive blood sample should be kept for look-back investigations in the event of an adverse reaction. This must be for a minimum of 11 years after the expiry date of the tissue with the longest storage life.
Tissues can be held for a number of years prior to issue. During this period in storage there may be changes to the mandatory microbiology test requirements and improvements in screening assays for mandatory or other markers. Consideration should be given for an additional blood sample archive for tissues with a long expiry for possible future testing that is not currently available.
A policy regarding the need for re-testing of the tissue inventory needs to be established. Any policy adopted must be operationally feasible and will depend on both the maximum storage period of the tissue and the probability of the tissue being issued. When new, or significantly improved, mandatory tests are introduced consideration should be given to the re-testing of archive samples from the donors of tissue still in issuable stock. Where there is no archive sample available to test, a risk assessment must be performed. It should include factors such as the seriousness of the infection, any viral inactivation procedures performed on the tissue, the effect on inventory of discarding such tissues and the severity of impact of possible tissue shortages on recipients.