Last update:
02-Jun-2020

The use of immunoglobulin has been a cornerstone in the prevention of recurrent infections in patients with primary immunodeficiencies (PIDs). The currently available administration options are the intravenous (IVIG) and the subcutaneous (SCIG) routes. Numerous studies have indicated equivalent effectiveness in protection against infections in the two methods. Over the past three decades, monthly intravenous administration has been the standard choice of treatment. The subcutaneous route, however, has gradually gained ground and is now preferred by clinicians, given that it presents a low rate of systemic side effects, it does not require venous access and it offers increased independence and scheduling flexibility, being associated with home-based, self-administered treatment. This review provides an overview of the evolutionary stages of immunoglobulin replacement therapy, and the specific characteristics of each route of administration, including their pharmacokinetics and dosage regimens. The inherent differences between the two forms of treatment are discussed, along with the advantages and limitations of each method and the factors to be considered in the selection of the preferred route. IVIG has been associated with a higher incidence of serious, systemic side effects and a lower level of treatment satisfaction. Although SCIG serves as a safe alternative for patients with poor venous access and low tolerability of IVIG, the preferred route of administration is not the same for all patients with PIDs. The different properties of each route of administration should be evaluated in relation to the disease-specific features and the patient's preference, in order to tailor a treatment regimen which meets the needs of the individual patient.

Key words: Immunoglobulin, Immunoglobulin replacement therapy (IRT), Intravenous immunoglobulin (IVIG), Primary immunodeficiencies (PIDs), Subcutaneous immunoglobulin (SGIG).