I don't have experience with IVIG. I did want to let you know that subcutaneous IVIG is available through Walgreen's Speciality Pharmacy. It's called Hizentra. You are "trained" how to do it and then can do it at home. It's not without side effects though. Nothing is. I hope your treatments go well, as well as the thymectomy. Good luck and quick healing.
Annie
http://www.walgreens.com/pharmacy/specialtypharmacy
http://www.hizentra.com/