Using Intravenous Immunoglobulin (IVIG) to Treat Patients with Primary Immune Deficiency Disease

The treatment of primary immunodeficiency disease (PIDD) patients with immunoglobulin obtained from healthy controls, given intravenously, is a relatively recent event, having first been given in 1981. Intravenous immunoglobulin (IVIG) replacement in PIDD has been shown to prevent serious/recurrent infections because higher IgG levels can be obtained through IV administration, as opposed to the intramuscular route. Significant variation in IgG levels in controls is dependent on age and sex, which provides the rationale for the concept that there is a "biological IgG trough/level", hereafter called biological IgG level, in PIDD, as there is in healthy controls. Each PIDD patient has a biological IgG level that can be altered by comorbid conditions that evoke IgG loss or changes in metabolism/catabolism. The pharmacokinetic comparison of IVIG vs. SCIG demonstrates the various benefits of each in treating PIDD. Acutely ill PIDD patients should only receive IVIG. "Rush" SCIG treatment can also be used to attain the biological IgG level, but for less emergent care of PIDD. Finally, future opportunities exist to enhance IgG replacement in PIDD, including microbe-specific IgG and IgG subclass-specific enriched preparations.