Common Variable Immunodeficiency Support Group
Common variable immunodeficiency (CVID) is a group of 20-30 primary immunodeficiencies (PIDs) which have a common set of symptoms but with different underlying causes. CVID's underlying causes are different, but the result of these are that the body doesn't produce sufficient antibodies in response to exposure to pathogens.
As for the IGG, my doctor said that the antibodies in IVIG have a 1/2-life of 3 months, so that with regular infusions your IGG levels reach a higher steady state than might be normal. My doctor told me that it would take 5-6 months for my IGG levels to get high enough to make me feel better at its lowest point, and the test that she did was the 6-month check to see what level it had reached. She called the test a "Trough".
Here's the medical definition of trough...I was curious and thought others might be interested too:
"peak and trough specimens,
serum samples collected to determine the level of an antibiotic or other pharmaceutic agent in the blood. Peak specimens, which represent the highest level, are generally collected hour after the dose is given intravenously or 1 hour after it is given intramuscularly. Trough specimens, representing the lowest level, are generally collected approximately hour before the next dose. See also peak method of dosing." (from http://medical-dictionary.thefreedictionary.com/peak+and+trough+specimens)
I was told this at the infusion center.
I was told a woman who was very ill with either PID or CVID was unable to keep an IV working.
She was switched to this and she has been fine since that time.
Usually, I can only use a rate of 30.''[
I did get it up to 40 this at this last time.