Donor marker testing algorithms are very complex and serve multiple objectives:
- Is the blood safe for the recipient, i.e. minimize likelihood of disease transmission?
- How do we to counsel the affected donor? Does he need referral for treatment or follow-up?
Often the donor disposition is unclear based on a single encounter and a temporary deferral must be triggered so the current results may be compared to future ones, usually after 8 weeks, 6 months, or one year—depending on the pathogen in question.
Regretfully, the significance of reactions that do not meet the criteria for positivity may be unclear. It is very difficult to explain to the donor that he has abnormal results and cannot donate but we as physicians do not know what their significance is.
Thus, the testing algorithms may trigger current additional testing, temporary deferral with repeat of testing at some future date, or permanent deferral.
At my previous positions, I started with the AABB/FDA CBER Uniform Donor Questionnaire UDQ and then modified it to include some advanced methodologies not available in the USA.
In the next series of posts I will elaborate on the processes developed for this for each marker.
To Be Continued