Every day, thousands of people lie on a couch and have their arm stabbed with a large needle. Blood from the venipuncture snakes down into a container. In some individuals, this continues until the volume is about a pint – 500 mL; for this, they get a cookie and a glass of juice. In others, the collection is larger – around 2,500 mL; for this, they get between $50 to 90, sometimes more.
For the first person, the collection takes perhaps 20 minutes. For the second, it is more like 45 to 60 minutes, and the blood is not taken all at once but rather in cycles, with most of it being returned.
Our first donor is giving blood; the second is donating “source” plasma that will be used to generate medicinals.
The process of plasma donation is known as plasmapheresis. The venous blood is mixed with citrate anticoagulant and flows into a complex machine, which has a centrifuge at its heart, spinning and separating the cellular content from the plasma, which is siphoned off into a bottle. The machine then reverses direction, and the cells are returned to the donor, who has been lying comfortably on the couch throughout. This cycling happens several times until about 600 to 800 mL of plasma is obtained. Finally, 500 mL of normal saline is infused to make up for the plasma loss. About 2.5 L of blood has passed through, but most of it has been returned. The entire procedure, though supervised by trained staff, is automatic.
I am the medical director for a plasmapheresis center here in the U.S., and we process about 200 to 300 donors per day. The parent company has more than 400 centers worldwide and employs over 27,000 individuals in these and its processing plants, where the plasma is turned into the medicinals, including albumin, alpha-1 proteinase inhibitor, various immunoglobulins, and blood clotting factors. This is big business, and it saves lives.
Being a plasma donor is gratifying and is a source of income for some people because, unlike blood donors, they can donate up to twice a week. However, becoming a donor is not simple.
Applicants are screened to ensure that the procedure will be safe for them and, most importantly, whether their plasma will be safe for others. A particular concern is bloodborne pathogens; another is autoimmune disease and previous blood cancers. There is an extensive list of medical conditions that will disqualify an applicant.
Screening includes extensive questioning to identify individuals at high risk for disqualifying features and is administered on multiple occasions. Applicants then undergo a standardized physical exam by trained medical staff. Part of my job is to make sure this screening is performed correctly and according to FDA requirements (Code of Federal Regulations Title 21).
Applicants who pass all these requirements then become donors, but surveillance is ongoing. At each visit, the donor’s hematocrit and plasma total protein are measured, and donation is only allowed if these are within strict ranges. They are questioned about high-risk behavior, and every donation is screened for HIV, hepatitis B, and hepatitis C through a combination of serology and nucleotide amplification testing. Syphilis serology is repeated every four months, along with plasma electrophoresis to ensure that the plasma components are within range.
Health care providers in towns with plasmapheresis centers can provide support by responding to communications from the latter regarding their patients who are applying to become donors. Often, further information about their drug regimens or medical status is needed before donation can be approved.
Applicants may be referred to their primary care provider (PCP) by the center when the screening exam picks up a previously unnoticed abnormality, e.g., atrial fibrillation. Established donors will be referred if the bloodborne pathogen screening becomes positive or the protein electrophoresis is persistently abnormal. Great care is taken not to “diagnose” disease when a positive test occurs; the possible implications are explained, and follow-up with the PCP is strongly recommended. Perhaps our most common precipitant for this is newly positive syphilis serology.
Plasmapheresis is an important source of rare medicinals. The procedure is highly regulated to ensure the safety of both the donor and the recipient. Please help us in our endeavors.
Martin C. Young is a pediatric endocrinologist.