What is Blood Plasma?
Blood plasma is the liquid component of whole blood, making up approximately 55% of its volume. It is a complex mixture of water, salts, enzymes, antibodies, and other proteins essential for key bodily functions. Unlike red blood cells, which transport oxygen, plasma's role is to carry vital nutrients, hormones, and proteins throughout the body. For individuals with specific chronic or rare diseases, deficiencies in these plasma proteins can lead to life-threatening conditions. This is where plasma-derived medicinal products (PDMPs) become essential.
Key Plasma-Derived Medicinal Products
PDMPs are created by processing large pools of donated human plasma through a manufacturing process called fractionation. This process isolates specific therapeutic proteins, which are then used to create medicines. Several major types of PDMPs are in widespread use today:
Immunoglobulins (IVIG)
Immunoglobulins, or antibodies, are proteins vital for fighting off infections. Intravenous immunoglobulin (IVIG) is a concentrated mixture of antibodies derived from the plasma of thousands of donors. It is used to treat patients with primary immunodeficiency (PI), autoimmune disorders, and certain neurological conditions by bolstering their immune systems.
Coagulation Factors
Coagulation factors are proteins responsible for blood clotting. Individuals with bleeding disorders like hemophilia A (Factor VIII deficiency) or hemophilia B (Factor IX deficiency) lack these factors, leading to uncontrolled bleeding. Plasma-derived coagulation factors are concentrated preparations that replace the missing proteins, enabling proper blood clotting.
Albumin
Albumin is a protein that plays a crucial role in regulating blood volume and pressure. In emergency medicine, it is used to treat patients suffering from shock, severe burns, or trauma by restoring lost blood volume. Albumin is also used to treat certain severe liver and kidney diseases.
Alpha-1 Proteinase Inhibitor (A1PI)
This protein protects the lungs from damage caused by inflammation. Patients with Alpha-1 Antitrypsin Deficiency, a genetic condition, have low levels of A1PI, putting them at high risk for severe lung and liver disease. Plasma-derived A1PI therapies provide the missing protein, helping to protect the lungs.
C1 Esterase Inhibitor
Used to treat hereditary angioedema (HAE), a rare genetic disorder that causes episodes of severe swelling. C1 esterase inhibitor concentrate helps regulate the biochemical pathways that cause the swelling attacks.
The Plasma Manufacturing Process: From Donation to Drug
The journey from donated plasma to a finished medicinal product is a complex, multi-stage process that can take up to a year. It starts with collection and ends with a rigorously tested and purified therapeutic drug.
- Collection: Plasma is collected from healthy, voluntary donors through a process called plasmapheresis, where the plasma is separated from the other blood components, which are then returned to the donor.
- Pooling: The collected plasma from thousands of individual donors is pooled together to ensure a robust supply and to concentrate the necessary proteins.
- Fractionation: The pooled plasma undergoes a process called fractionation, historically based on the Cohn process. This uses controlled changes in temperature, pH, and alcohol concentrations to precipitate and separate specific therapeutic proteins. Modern techniques also incorporate chromatography and filtration for greater purity.
- Purification and Viral Inactivation: The isolated protein fractions are further purified. To ensure safety, they undergo multiple viral inactivation and removal steps designed to eliminate potentially infectious agents like HIV and hepatitis viruses.
- Final Product: The purified, inactivated proteins are formulated, filled into vials, and prepared for final release as a medicinal product.
Plasma-Derived vs. Recombinant Therapies
For some conditions, like hemophilia, both plasma-derived and recombinant (lab-produced) versions of therapeutic proteins exist. While both are effective, they differ significantly in their source and manufacturing.
| Feature | Plasma-Derived Therapies | Recombinant Therapies |
|---|---|---|
| Source | Donated human plasma from thousands of individuals. | Genetically engineered cell lines (e.g., Chinese hamster ovary cells). |
| Production Process | Complex, multi-step fractionation and purification. Requires significant volumes of donated plasma. | Lab-based cell culture and purification. Does not depend on human donors. |
| Safety | High safety standards with modern viral inactivation steps, but carries a theoretical, though minimal, risk of new pathogen transmission. | Eliminated risk of human-derived pathogen transmission. |
| Immunogenicity | Some evidence suggests plasma-derived factor VIII may be less immunogenic than older recombinant versions due to the presence of other stabilizing proteins. | Varies by generation and specific product. |
| Availability | Dependent on the continuous supply of donated human plasma, which can fluctuate. | Production is scalable and not dependent on human donation cycles. |
| Cost | Typically higher manufacturing costs due to reliance on human donors and complex processing. | Can be very expensive, though costs vary by specific therapy. |
The Future of Plasma-Derived Therapies
Despite the rise of recombinant alternatives, PDMPs remain crucial for global health, especially for conditions where no recombinant alternative exists. Research continues to improve manufacturing techniques, enhancing safety and increasing the yield of therapeutic proteins from donated plasma. Additionally, new PDMPs and applications for existing products are constantly being explored. The continued need for plasma highlights the vital role that plasma donors play in sustaining these life-saving treatments.
Conclusion
In summary, what drugs are made out of plasma are a wide array of indispensable biopharmaceuticals that treat rare and chronic diseases affecting millions worldwide. From immunoglobulins that fortify compromised immune systems to clotting factors that manage bleeding disorders and albumin that stabilizes trauma patients, these medicines are created from the generosity of human plasma donors through a highly sophisticated manufacturing process. The reliance on human donations makes plasma a uniquely precious and vital medical resource that cannot be artificially replicated, underscoring its profound importance in modern medicine.
