High quality human immunoglobulin G purified from Cohn fractions by liquid chromatography

Adapting the Cohn 6th cold ethanol fractionation method for small plasma pools: An innovative platform for developing hyperimmunoglobulin products against antibiotic-resistant infections in resource-limited settings

The growing challenge of antimicrobial resistance (AMR) requires innovative strategies to combat multidrug-resistant infections. Vaccination is an effective approach, often considered a potential solution, however, its application against some of the most challenging multidrug-resistant bacteria, has been unsuccessful so far. In contrast, passive immunotherapy using high-titer specific antibodies can offer immediate solutions for infections where conventional antibiotics fail. This study describes the adaptation of the Cohn 6th cold ethanol fractionation method for small plasma pools, enabling the production of high-quality intravenous immunoglobulin (IVIG) products in resource-limited settings. Using small-scale plasma batches (12 L), the modified protocol achieved a yield of 4.5 ± 0.2 g/L IgG with > 98 % purity, meeting European Pharmacopoeia requirements. Additional purification, viral safety, and filtration steps ensured sterility, low endotoxin levels, and robust viral inactivation. Safety evaluations confirmed sterility, absence of pyrogens, and stability over 24 months. This scalable methodology provides a practical platform for developing hyperimmunoglobulin products targeting AMR pathogens, particularly in resource-limited countries where large-scale fractionation infrastructure is unavailable and also not suitable. Our future efforts will focus on integrating this platform into combination therapies to enhance clinical outcomes in AMR infection management.

A new liquid, intravenous immunoglobulin product (IGIV 10%) highly purified by a state-of-the-art process

BACKGROUND AND OBJECTIVES

The ultimate goal was to generate an industrial-scale process suitable to produce a high-yield, safe and stable immunoglobulin G (IgG) preparation for intravenous administration, which is ready to use for customer convenience. This new liquid 10% IgG preparation (IGIV 10%) was compared to Gammagard SD, a licenced lyophilized immunoglobulin in biochemical and preclinical testing.

MATERIALS AND METHODS

The new process, which includes three dedicated virus clearance steps, is a streamlined combination of the currently applied and well-established manufacturing procedures. The biochemical characterization is done by standard methods focusing on purity, integrity and functionality of the preparation. Efficacy is demonstrated in vivo by mouse protection testing and in vitro by opsonization and protein A affinity chromatography. Pharmacokinetics in rats is evaluated after a single intravenous dose. The anaphylactoid potential is determined in rats and in guinea pigs, while thrombogenicity is assessed in a rabbit model. The influence of the products on vital functions is tested on dogs, while acute toxicity studies are carried out on mice and rats.

RESULTS

The biochemical characterization data demonstrate the high purity of monomeric IgG in the product. The mouse protection test showed that the protective activity against systemic bacterial infections of IGIV 10% is at least as good as the reference Gammagard SD. This result is supported by the broad spectrum of antibodies in high titres against bacteria and viruses and the high functional integrity of the IgG molecule (> or = 90% functionally intact IgG) in IGIV 10%. The opsonic activity of all IGIV 10% lots is similar to the one of the reference Gammagard SD. In safety and thrombogenicity studies, no adverse effects of IGIV 10% were observed. Pharmacokinetic studies showed no statistically significant differences between the two products. In the acute toxicity animal studies, IGIV 10% compared favourably to the reference Gammagard SD.

CONCLUSIONS

The new manufacturing process enables the production of a highly purified IgG preparation for intravenous administration. The product has an IgG subclass distribution similar to plasma and contains a broad spectrum of functionally intact antibodies. Preclinical studies demonstrate that the liquid IGIV 10% combines excellent qualities of efficacy, safety and tolerability.

Purification of intravenous immunoglobulin G from human plasma – aspects of yield and virus safety

Plasma-derived intravenous immunoglobulin (IVIG) preparations have been successfully applied for the prophylactic prevention of infectious diseases in immunodeficient patients. In addition to its replacement therapy of primary and secondary antibody deficiencies, IVIG has found increased use in autoimmune and inflammatory diseases. IVIG has become the major plasma product on the global blood product market. The world wide consumption nearly tripled between 1992 and 2003, from 19.4 to 52.6 tons. Classical manufacturing processes of IVIG, but also new strategies for purification are discussed with respect to practicability and yield. Ethanol fractionation is still the basis for most IVIG processes, although isolation and purification of immunoglobulin G (IgG) by chromatography has gained ground. The efficiency of virus inactivation methods and virus removal techniques in terms of logarithmic reduction factors are analyzed, but also the IgG losses are taken into consideration. Some of these methods also have the ability to separate prions. High pathogen safety and high yields have become the dominant goals of the plasma fractionation industry.

Anticomplementary activity of equine whole IgG antivenoms: comparison of three fractionation protocols

Early adverse reactions occur in a number of patients treated with heterologous antivenoms and have been associated with anticomplementary activity (ACA). In order to reduce the ACA of equine whole IgG antivenoms produced by caprylic acid fractionation, three different fractionation protocols were compared: (a) routine caprylic acid fractionation; (b) caprylic acid fractionation followed by beta-propiolactone treatment; and (c) caprylic acid fractionation followed by ion-exchange chromatography using a quaternary ammonium membrane. The three protocols yielded products with similar physicochemical characteristics and anti-Bothrops asper venom antibody titers, except that ion-exchange purified antivenom had a lower protein concentration. Antivenoms fractionated by using beta-propiolactone or filtration through quaternary ammonium membrane had a significantly reduced in vitro ACA. A preparation of caprylic acid-fractionated antivenom was heated in order to induce the formation of protein aggregates; however, its ACA was similar to non-heated antivenom. None of the antivenoms affected the hemolytic activity of serum complement in rabbits after a bolus intravenous administration. It is concluded that (a) beta-propiolactone and quaternary ammonium membranes significantly reduce in vitro ACA of caprylic acid-fractionated equine antivenom, and (b) the validity of in vitro ACA as a predictor of EAR needs to be reexamined in clinical and experimental studies, since it may not adequately predict in vivo complement activation by antivenoms.

Hypotension with intravenous immunoglobulin therapy: importance of pH and dimer formation

Therapy with intravenous immunoglobulin preparations has been used effectively in a wide range of conditions. Although generally well tolerated, intravenous immunoglobulin preparations may be associated with transient hypotension in some patients. This study examined the role of different immunoglobulin G fractions in the development of intravenous immunoglobulin-induced hypotension in an anaesthetized rat model and assessed the effects of a new liquid immunoglobulin prepared at a low pH on both the formation of immunoglobulin G dimers and the development of hypotension. The effects of this new preparation in an experimental autoimmune encephalomyelitis model were also evaluated. Results from the haemodynamic studies indicated that immunoglobulin G dimers in polyclonal immunoglobulin G are responsible for the hypotensive events associated with some immunoglobulin preparations. They also showed that adjustment to an acidic pH results in the rapid dissociation of immunoglobulin G dimers and prevents the development of hypotension. Additional experiments demonstrated that only immunoglobulin G dimers with a functional Fc fragment can bind to Fcgamma receptors on macrophages to induce the release of blood pressure-lowering mediators. Moreover, essentially monomeric Fc fragments can block the blood pressure-lowering effects of immunoglobulin G dimers. Preparation of a new liquid intravenous immunoglobulin with the pH adjusted to 4.3 prevents the formation of immunoglobulin G dimers even over long-term storage and does not significantly affect blood pressure in a rat model. This preparation is as effective as other intravenous immunoglobulin preparations in ameliorating symptoms of experimental autoimmune encephalomyelitis. These results, like those from previous studies, indicate that preparation of intravenous immunoglobulin at a low pH substantially reduces immunoglobulin G dimerization; this effect significantly decreases the potential for intravenous immunoglobulin to induce hypotension without reducing its clinically relevant biological activity.