Safety of plasma derivatives.
In clinical treatment practice of substitution therapy involving a plasma component, numerous aspects related to recipient's safety are relevant to the physician. Since viral contaminants may be present in the donor blood, safety begins in the institution collecting raw plasma where donors are inquired about any unusual behavior that may potentially threaten safety. Other measures that could lead to exclusion of a donation are positive serological tests for HIV and hepatitis B and C. In this context, meticulously accurate logistics are mandatory. During the course of manufacture of plasma products, viral inactivation procedures have been adopted based on chemical and physical principles. The distinct effects of these depend on methodology and the types of virus in question. An important safety measure relates to establishing that the label value of content corresponds to the in vivo recovery of the reconstituted plasma derivative and, by inference, the clinical efficacy of the product. In patients deficient in plasma coagulation factors, treatment may trigger the development of functionally inhibiting alloantibodies against the factor needed for substitution which is a significant clinical complication. The reported incidences of such inhibitors have varied greatly. No clear relationship between their frequency and the type of concentrate used have been established. However, recent experience has shown an unexpected increase in inhibitors in a regional subset of previously stable patients when shifted from a dry-heat-inactivated concentrate to a pasteurized version of the same concentrate. Hence, the possible introduction of neoantigens is important. In the early era of concentrate use, side effects to treatment were often observed like alloimmune hemolytic anemia and various degrees of anaphylactoid reactions. With the appearance of concentrates of increased purity that contain less unwarranted proteins, side effects of this kind have been rare. In conclusion, safety of plasma derivatives by today's standards is not a single entity, but a long chain of interdependent issues, each of which needs full attention to protect patients from mild and serious treatment complications.
Department of Clinical Immunology, University Hospital, Aarhus/Skejby, Denmark.
J
J
Ingerslev
D001779:Blood Coagulation Factors / Q000009:adverse effects*; D016913:Blood Component Transfusion / Q000009:adverse effects*; D001782:Blood Donors; D006505:Hepatitis / Q000517:prevention & control; D006801:Humans; D007108:Immune Tolerance; D010949:Plasma / Q000737:chemistry*; D012449:Safety; D014777:Virus Diseases / Q000635:transmission
D001779:Blood Coagulation Factors