Plasma donation collects the liquid portion of blood, plasma, for life-saving therapies. Many donors ask why a second donation is required for their plasma to be usable. This stems from stringent safety protocols ensuring donor health and product efficacy.
Initial Donation and Plasma Testing
During the first plasma donation, a process called plasmapheresis is used. This involves drawing whole blood from a donor, separating the plasma from the red blood cells and other components, and then returning the remaining blood components to the donor. The initial visit includes a health screening, a physical exam, and a blood sample collection to check vital signs and suitability for donation.
After this first donation, the collected plasma undergoes tests for infectious diseases, including HIV, Hepatitis B, and Hepatitis C. These tests use methods like nucleic acid amplification testing (NAT) to detect viral genomes. However, a challenge arises from the “window period” of some infections—the time between initial infection and detectable levels. Because of this incubation period, a single negative test result from the first donation is not considered sufficient to guarantee the plasma’s safety for patient use. Consequently, plasma from a first donation is typically quarantined and not immediately released for manufacturing.
Confirming Donor Health and Plasma Safety
The requirement for a second donation establishes a “look-back” period, enhancing the safety of the plasma supply. If a donor returns for a second donation, and subsequent tests on samples from both donations are negative, it provides a higher level of assurance regarding the donor’s health status. This second negative test helps confirm that the donor was likely not in the “window period” of an undetected infection during the initial donation.
Regulations, such as those from the FDA, stipulate that plasma from the first donation cannot be used until a second donation is made and both donations test negative for infectious agents. This second donation typically occurs within a specific timeframe, usually within six months of the first. Only after both donations have yielded negative test results is the plasma from the first donation released for use. The plasma collected during the second donation is also held until a subsequent donation confirms its safety, continuing this cycle of verification.
Benefits of the Two-Donation Protocol
This two-donation system enhances the overall safety of the plasma supply for patients. It minimizes the risk of transmitting infectious diseases by providing an additional layer of verification beyond initial testing. The protocol helps maintain public trust in the safety and integrity of plasma-derived therapies, which are used to treat conditions like immune deficiencies, bleeding disorders, and severe burns. This system also contributes to a stable and reliable supply of safe plasma, ensuring that medical treatments and drug manufacturing processes have access to high-quality raw material.