Chapter 7-Fractionated blood products and associated pathogen safety Flashcards
How are recombinant plasma protein products made?
Made by culturing mammalian cells transfected with nucleic acid vectors carrying the gene of interest.
The plasma protein is secreted into the culture medium, which is then harvested, purified, and formulated for therapeutic use.
What has the evolution of manufacturing processes achieved in terms of viral contamination risk?
Incremental reduction in viral contamination by eliminating plasma and albumin from production and formulation steps.
What is a first-generation recombinant product?
Products that incorporate small amounts of residual human plasma proteins, usually albumin, used during cell culture and final formulation steps.
What is a second-generation recombinant product?
Products that eliminate plasma proteins from the final formulation steps but may still use plasma during cell culture.
What is a third-generation recombinant product?
Products like Advate (rFVIII) or Niastase RT® (rFVIIa), which are made without human or animal proteins in either cell culture or final product formulation.
How do longer-acting recombinant products achieve extended half-life?
By conjugating clotting factors to polyethylene glycol (PEG) or fusing clotting factors to albumin or immunoglobulin G (IgG) constant region (Fc).
What processes ensure the safety and potency of recombinant products and incorporated into the manufacturing process.?
Specific viral inactivation/partitioning procedure
*Virus inactivation/reduction procedures like
1-solvent detergent treatment,
2-nanofiltration, or
3-heat/pasteurization
What methods are used during the manufacturing process to reduce pathogen transmission?
Name 2 other than solvent detergent method
Manufacturers use a combination of two or more complementary processes to reduce pathogen transmission.
1- Chromatography and nanofiltration
2- Heat treatment
3- Caprylate or solvent-detergent treatment
How is the effectiveness of pathogen inactivation processes validated?
By determining pathogen recovery from microbially-contaminated test samples after inactivation treatment.
What has been shown to effectively remove prion protein from plasma derivatives?
Various manufacturing steps have been shown to remove prion protein.
How does the fractionation process reduce contamination?
Reduces bacterial, viral, and probably prion contamination by using changes in pH, temperature, and ethanol concentration, which keep microbial contamination low and physically disassociate viruses from proteins.
What do chromatography and nanofiltration achieve in pathogen reduction?
They provide incremental pathogen reduction and enhance the purity of the product.
What types of heat treatment are used for pathogen inactivation?
Dry, steam, or wet (pasteurization), with specific temperature, pressure, and time pre-determined for each product to inactivate pathogens without compromising biological activity.
How does caprylate or solvent-detergent treatment work in pathogen reduction?
Effective against lipid-enveloped viruses (e.g., HIV, hepatitis B, and hepatitis C). Solvents and detergents disrupt the lipid membrane of viruses, which are then removed later in the process.
How are plasma-derived protein products made?
Made by pooling plasma from large numbers of donors (typically >10,000) and fractionating the different plasma constituents.
What was the original fractionation process used for plasma-derived protein products?
The Cohn fractionation process, introduced in the 1940s,** which** uses variations in protein concentration, ethanol concentration, ionic strength, temperature, and pH to precipitate plasma fractions.**
What modern technologies are used in the fractionation process today?
Chromatography
Monoclonal affinity columns
Nanofiltration
What are the transfusion-transmissible disease prevention steps in plasma-derived protein production?
Screening donors using sensitive serologic and nucleic acid tests for infectious agents (e.g., HIV, hepatitis B, hepatitis C).
Multiple safety steps are incorporated before, during, and after the fractionation process.
What is the estimated risk of known blood-borne infectious agents in plasma-derived products?
The risk ranges from less than one in a million to less than one in 10 million.
How safe are plasma-derived protein products in terms of infection risk in Canada?
Since the introduction of modern manufacturing practices in the 1980s and 1990s, there has been no transmission of HIV, hepatitis B, or hepatitis C via plasma protein products in Canada.
What is included in donor health screening for plasma donation?
Health assessment at the time of each donation.
Exclusion of donors with specified risk factors for blood-borne infections, including potential exposure to prion diseases (e.g., Creutzfeldt-Jacob Disease (CJD) or variant-CJD).
How are donated plasma units tested for pathogens?
Laboratory testing includes **nucleic acid **and serologic tests for HIV, hepatitis B, and hepatitis C.
Donated units that test positive are discarded
What safeguards are in place for apheresis plasma donors?
- Defined weight-dependent maximum donation volume and cumulative annual donation volume.
- **Serum protein measurement **with each donation
- protein electrophoresis every 4 months.
- Annual physical examination.
Where does most of the plasma for fractionated plasma products in Canada come from?
From foreign donors, primarily paid plasma donors from the United States.
Do plasma protein products distributed in Canada meet safety standards?
Yes, they meet :
Health Canada,
2-Council of Europe (CE), and/or United States Food and Drug Administration (FDA) licensing requirements.
Plasma protein products from paid and unpaid donors are equally safe due to strict safety protocols.
How can clinicians access unlicensed plasma protein products in Canada?
Through Health Canada’s Special Access Program, on a case-by-case basis.
What additional testing is performed by plasma fractionators during the in-process stage?
Tests for non-lipid enveloped viruses like **parvovirus B19 and hepatitis A virus (HAV), **which are more resistant to inactivation during fractionation.
How does nucleic acid testing help in identifying problematic plasma units?
It identifies plasma units with high titers of parvovirus B19 or units that test positive for HAV, which are then removed from the manufacturing process.
What testing is done at the end of the manufacturing process for plasma-derived products?
Products are tested to ensure they are sterile and pyrogen-free.
Can the potential risk of disease transmission be completely eliminated in plasma-derived products?
No, the risk cannot be completely eliminated, but Good Manufacturing Practices and validated processes ensure very high standards of purity, potency, efficacy, and safety.
What are different type of factor VIII bases on source and shelf life
1- Factor VIII recombinant (rFVIII), human –standard half-life
2- Factor VIII, plasma-derived (pd FVIII) – standard half-life
3- Factor VIII recombinant – extended half-life
4- Factor VIII/VWF plasma-derived concentrate (pd FVIII/VWF) (licensed for von Willebrand disease and hemophilia A)
5-Porcine recombinant FVIII (rpFVIII)
when to use chromomogenic essay in PT receiving Factor VIII?
Factor VIII recombinant – extended half-life for all except Elocate (Standard aPTT).
How many type of VWF available?
1- Factor VIII/VWF plasma-derived concentrate (pd FVIII/VWF)
2- Von Willebrand factor concentrate, recombinant (rVWF)
Dose calculation for factor concentrate (other than fibrinogen)?
what is the maintenance dose?
Dose calculation for fibrinogen concentrate(other than fibrinogen)?
IVR: Invitro recovery