This is a single-site, pilot study conducted in the US to determine the benefit of human C1-esterase inhibitor \[recombinant\] (C1-INH-R) therapy to ameliorate ADRs in subjects receiving IVIG therapy experience ADRs post-infusion. Subjects who are currently receiving IVIG for immunodeficiency or neurologic conditions and experience ADRs will be enrolled.
In part 1, subjects will continue to receive IVIG for two infusions. Complement proteins will be measured pre- and post-infusion. Quality of life and other questionnaires will be administered.
In part 2, subjects will receive C1-INH-R infusion prior to receiving IVIG infusion for three infusions. Complement proteins will be measured pre- and post- infusion. Quality of life and other questionnaires will be administered.
