Immunoglobulin replacement therapy (IGRT) is a mainstay treatment for SAD and has been shown to reduce the risk of infection and increase quality of life in patients with SAD. Current guidelines recommend that patients with severe hypogammaglobulinemia (IgG <4 g/L) or patients with a history of recurrent or severe infections should be offered IGRT, which can be administered intravenously on a monthly basis or more frequently by subcutaneous infusions. There are currently no clinical guidelines for IGRT discontinuation. Although research conducted at the Ottawa Hospital indicates successful discontinuation of IGRT, clinicians need a tool to predict the recovery of humoral immunity and the risk of infection in these patients in order to determine whether IGRT may be safely discontinued.
Current treatment for patients with secondary antibody deficiency (SAD) is Immunoglobulin replacement therapy (IGRT). There are currently no clinical guidelines for IGRT discontinuation in patients with SAD. This study will examine the IGRT discontinuation success rate and IGRT discontinuation rate in patients.