Ensuring the pathogen safety of intravenous immunoglobulin and other human plasma-derived therapeutic proteins

Allergen stability of testing/treatment boards and immunotherapy vials with various diluents

BACKGROUND

Otolaryngologists commonly use glycerin and normal saline with phenol (NSP) in diluting solutions to help preserve allergenicity in immunotherapy vials. Studies have shown that diluting with human serum albumin (HSA) may provide better allergen stability. The purpose of this study was to assess the ability of various diluents to preserve allergen content in testing/treatment boards (TTBs) and immunotherapy treatment vials (ITVs) at multiple time points.

METHODS

TTBs with 4 allergens were prepared with HSA, NSP, 10% glycerin, and 50% glycerin. The major allergen content of the TTBs was measured at creation (time 0), 3 days, 8 weeks, and 18 weeks. Multiallergen ITVs containing the 4 allergens were prepared from the NSP board (diluted to 10% glycerin) and the HSA board (diluted in HSA) at the time of making the freshly prepared TTBs and again 8 weeks later, simulating the creation of ITVs from a "new" and an "old" TTB. The major allergen content of these ITVs was determined at creation and at interval time points thereafter.

RESULTS

TTBs and ITVs showed a substantial loss of allergen at day 3. The loss of allergen was more pronounced in the more dilute (#4, #5, and #6) vials. HSA and 50% glycerin showed superior allergen preservation compared to NSP and 10% glycerin in TTBs. HSA showed superior allergen preservation compared to 10% glycerin-NSP in ITVs.

CONCLUSION

The use of HSA as a diluent in TTBs and ITVs showed superior allergen preservation compared to NSP and 10% glycerin, particularly for more dilute vials.

Therapeutic applications of extracellular vesicles: clinical promise and open questions

This review provides an updated perspective on rapidly proliferating efforts to harness extracellular vesicles (EVs) for therapeutic applications. We summarize current knowledge, emerging strategies, and open questions pertaining to clinical potential and translation. Potentially useful EVs comprise diverse products of various cell types and species. EV components may also be combined with liposomes and nanoparticles to facilitate manufacturing as well as product safety and evaluation. Potential therapeutic cargoes include RNA, proteins, and drugs. Strategic issues considered herein include choice of therapeutic agent, means of loading cargoes into EVs, promotion of EV stability, tissue targeting, and functional delivery of cargo to recipient cells. Some applications may harness natural EV properties, such as immune modulation, regeneration promotion, and pathogen suppression. These properties can be enhanced or customized to enable a wide range of therapeutic applications, including vaccination, improvement of pregnancy outcome, and treatment of autoimmune disease, cancer, and tissue injury.

Defining "adequate" pathogen reduction performance for transfused blood components

Pathogen reduction of labile blood products offers the opportunity to introduce to the blood banking community the same mechanism of protection that is employed for fractionated or pooled plasma products today--blood components that have been treated with methods to inactivate or reduce the infectivity of a variety of organisms that may contaminate donated blood and thus potentially transmit infection via transfusion. Due to the mechanisms of action, the methods employed in the plasma fractionation environment are not directly applicable to labile blood products. This article examines whether the same criteria of performance required for plasma derivatives (i.e., 6 log/mL reduction by multiple orthogonal methods) should be applied to the treatment of labile components and if not what criteria for performance might be sufficient. In conducting this analysis, we have considered what has been learned in the past several decades regarding the dynamics and infectivity of various pathogens and disease transmission by blood products, the introduction and progressive enhancement of testing methods based on serology and nucleic acid testing, and the performance characteristics for pathogen reduction technologies that are available today.

History of immunoglobulin replacement

The provision of antibodies to prevent and treat infection began with the application of "curative serum" in the first years of the last century. After the process of large-scale plasma fractionation was developed in the 1940s, the general use of immunoglobulin expanded. Intravenous immunoglobulin products became available in the 1970s, and their only use for the provision of antibodies governed the opinion of experts over the next decade. Modulation of inflammation and immunosuppression were introduced in treatment of inflammatory and autoimmune diseases and became accepted indications. The history of adverse events of treatment and their management are outlined in this article. Consensus indications and evidence-based off-label uses are discussed.

Design of Adsorptive Columns for Specific Pathogen Removal: Application to Staphylococcal Enterotoxin B

The removal of pathogens such as toxins, viruses, bacteria, and prions in human blood, mammalian cell culture media, fermentation broths, food items, and water streams has gained increasing importance in ensuring product safety and in combatting acts of terrorism. Adsorption processes can play an important role in removing such pathogens from solution without affecting other desirable components. Adsorptive columns that can remove specific families of pathogens would need to achieve a reduction of several logs in pathogen concentration. This requirement is much more stringent than the normal yield requirements associated with adsorptive separations aimed at product recovery and purification in a process stream. This paper considers the design of an adsorptive column aimed at reducing the concentration of infectious agents from a known volume of solution by several logs in a fixed amount of time. The general rate (GR) model of chromatography is used in the analysis, including all major transport and kinetic steps in the adsorption process. The theory, with no adjustable parameters, is shown to predict with great accuracy the effect of residence time on the log removal of staphylococcal enterotoxin B (SEB) from solution using an affinity resin with a small peptide (YYWLHH) that has been found to bind specifically to this toxin.

Immune globulin IV therapy: optimizing care of patients in the oncology setting

PURPOSE/OBJECTIVES

To review major clinical applications of immune globulin IV (IGIV) therapy, properties of currently available IGIV preparations, procedures for dosing and administration, management of infusion-related adverse effects, and strategies for effective patient education.

DATA SOURCES

Published articles, abstracts, and textbook chapters.

DATA SYNTHESIS

IGIV therapy supports immune function by providing immunoglobulin G antibodies for protection against pathogens and modulation of autoimmune and other potentially damaging host responses. Licensed uses include treatment of primary immune deficiencies and autoimmune conditions and prophylaxis against viral infection.

CONCLUSIONS

The safety and effectiveness of IGIV therapy depend on selection of an appropriate product, dosage, and infusion rate; patient comorbidities and other risk factors; and patient education and treatment adherence.

IMPLICATIONS FOR NURSING

Nurses have an essential role in the safe and effective use of IGIV, from educating patients about the rationale for and effects of therapy to administering the product and monitoring for adverse effects.

The process: New methods of purification and viral safety

From the transmission of hepatitis C virus by gammaglobulins in 1994 to the emergence of new viruses and concern over prions, intravenous immunoglobulin (IGIV) manufacturers have continued to address safety issues and respond to changing needs. New IGIV products not only provide superior antiviral safety, but also show advances in product purity and manufacturing processes. Several manufacturers have also addressed the concern over prion transmission. The sum of the processes used have collectively ensured continuous product safety. Newer products will be further differentiated by their tolerability and efficacy profiles.

Pharmacy considerations for the use of IGIV therapy

PURPOSE

A number of immunoglobulin intravenous (IGIV) products have been approved by the Food and Drug Administration (FDA) and are available commercially. Factors that need to be taken into consideration when selecting an appropriate IGIV product are discussed.

SUMMARY

Pathogen safety is of particular concern in IGIV products. Manufacturers of IGIV products have introduced different steps to ensure pathogen inactivation and clearance. Physical viral inactivation methods include heat and pasteurization. Chemical viral inactivation methods include acidic treatment, solvent/detergent, and caprylate. Viral removal is accomplished via precipitation, chromatography, or nanofiltration. Pathogen inactivation processes may inadvertently affect IGIV product characteristics, including composition, concentration, purity, and yield, which may, in turn, affect tolerability, efficacy, and convenience of usage. Tolerability of IGIV products is dependent on factors such as volume load, osmolarity, IgA content, and stabilizing agent. For example, sucrose, used as a stabilizing agent in some IGIV products, has been associated with an increased risk of IGIV-induced acute renal failure. The qualities of IGIV products that contribute to convenience of usage for patients and healthcare professionals include liquid formulation, longer shelf life, multiple package sizes, and shorter infusion time. Cost effectiveness of therapy is another important consideration in IGIV product selection. Contributing factors to cost effectiveness include acquisition cost, reimbursement, product preparation, storage, shelf life, and adverse event management.

CONCLUSION

The various IGIV products differ in terms of production process, tolerability, and convenience. Pharmacists should be cognizant of these differences when ordering IGIV therapy for their patients. Additionally, overall cost-effectiveness of therapy should be an important consideration.

Sodium hydroxide renders the prion protein PrPSc sensitive to proteinase K

Sodium hydroxide (NaOH) solutions are widely used for the purification of contaminated equipment, as they are known to inactivate a variety of pathogens. However, information about their effect on agents causing transmissible spongiform encephalopathy (TSE) is sparse and contradictory. Scrapie hamster brain homogenate, containing the disease-associated form of the prion protein (PrP(Sc)), was exposed to NaOH. Kinetics studies showed that treatment of brain homogenate with millimolar concentrations of NaOH rapidly abolished the proteinase K-resistant form of the prion protein (PrP(res)). NaOH treatment converted PrP(Sc) into a protease-sensitive form, either in solution or when adsorbed to a metallic surface. If infectivity of TSEs is linked with PrP(res), the results imply that inactivation of TSE occurs more efficiently than currently assumed.