Subcutaneous IgG (SCIG) is becoming more popular, but there is still some uncertainty among physicians about efficacy and optimal dosing.
Efficacy of SCIG in preventing infections is proportional to the steady-state levels achieved, and similar to that of intravenous IgG (IVIG).
At equivalent total doses, weekly SCIG results in steady-state levels 10–20% higher than troughs on monthly IVIG. Risk of systemic reactions during SCIG infusion is less than 1%. Many patients prefer SCIG over conventional IVIG.
SCIG therapy has been widely used in European countries for years. The U.S. Food and Drug Administration approved the first SCIG product in 2006. Three preparations of SCIG have been licensed in the US in the past year. Their bioavailabilities are 65–70% of that of IVIG.
Hizentra is SCIG made by CSL Behring. It is 20% liquid immunoglobulin (Ig) therapy indicated for the treatment of patients with primary immunodeficiency disease (PIDD).
Here are some helpful links regarding SCIG and Hizentra specifically:
Hizentra Dosage Calculator
Nurse Locator helps yo find nurse agencies that staff nurses who completed the SHARE training program for SCIG:
Choices in IgG replacement therapy for primary immune deficiency diseases: subcutaneous IgG vs. intravenous IgG and selecting an optimal dose. Berger, Melvina. Curr Opin Allergy Clin Immunol. 2011 Dec;11(6):532-8.
Subcutaneous immunoglobulin replacement therapy for primary antibody deficiency: advancements into the 21st century. Moore ML, Quinn JM. Ann Allergy Asthma Immunol. 2008 Aug;101(2):114-21; quiz 122-3, 178.
HyQvia combines IgG Infusion 10% and hyaluronidase, packaged as a kit for treatment of primary immunodeficiency. Baxter, 2012.