JUST THE BASICS

IgG replacement is a therapy given to patients with immune deficiency who have low antibody levels. Because antibodies are important in fighting infections, people with low IgG levels can get severe infections like pneumonia. IgG replacement can be life-saving for people with immune deficiencies and help restore the ability to fight off these infections. IgG therapies are created by pooling the antibodies from thousands of blood donations. This cartoon reviews the fascinating history of IgG replacement, from the initial discovery of antibodies to the development of antibody infusions that people can now use at home.

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When antibody deficiencies were first discovered in the 1950s, IgG replacement was given in the form of intramuscular (IM) injections because attempts to give it intravenously led to severe reactions. Unfortunately, IM injections were painful, so only small amounts could be given, which didn’t provide full protection. It took decades to design a form of IgG replacement that could be infused into the veins, called IVIG. This was a great advance for patients with immune deficiency because they could now receive higher doses of antibody, which were better at preventing infection, and they no longer needed painful injections. Over the years, IVIG formulations have been tweaked to make them safer, and infusions have now been developed that can be given into the skin (called SCIG), which have reduced the risk of side effects even further.

Published in November 2022 Annals of Allergy, Asthma & Immunology: https://doi.org/10.1016/j.anai.2022.06.010