Intravenous immunoglobulin for infectious diseases: back to the pre-antibiotic and passive prophylaxis era?

Abstract

The dramatic increase in both the number of novel infectious agents and resistance to antimicrobial drugs has incited the need for adjunct therapies in the war against infectious diseases. Exciting recent studies have demonstrated the use of antibodies in the form of intravenous immunoglobulin (IVIg) against infections. By virtue of the diverse repertoire of immunoglobulins that possess a wide spectrum of antibacterial and antiviral specificities, IVIg provides antimicrobial efficacy independently of pathogen resistance and represents a promising alternative strategy for the treatment of diseases for which a specific therapy is not yet available.

Figure 1

Evolution of infectious diseases and microbial resistance. The optimism generated by the dawn of the antimicrobial era in the mid-1940s was soon quenched by the emergence of penicillin-resistant Staphylococcus aureus. The evolution of increasingly antimicrobial-resistant pathogens in both developing (a) and developed countries (b) stems from a multitude of factors that include: the widespread and sometimes inappropriate use of antimicrobials, the extensive use of these agents as growth enhancers in animal feed, the relative ease with which antimicrobial-resistant bacteria cross geographic barriers and widespread industrial and agricultural use. Indiscriminate use of antimicrobials and failed treatments with ‘old and simple’ drugs because of economic reasons in developing countries has also led to more severe disease or to the spread of infection, along with its contingent selection pressure, leading to the emergence of variants. Figure courtesy of J.M. Alonso.

Figure 2

Proposed mechanisms of action of intravenous immunoglobulin (IVIg) in infectious diseases. The mode of action of IVIg in infectious diseases involves its direct interaction with pathogens and various cellular and soluble components of the immune system. Abbreviations: APC, antigen-presenting cell; B, B cell; T, T cell.