if you read the forum lone enough you will find the stuff effects each one different.For me I have been on IVIg for two years. my Neuroligist would not consider steroids because of side effects. my issue is pain not mobility. I have improved lots since I started 40grams monthly. if you chart your condition with your schedule of IVIg, weather,stress,and tons of other factors you will find some days a truck ran over you and some days you fell OK. that was what my neuroligist told me about any autoimmune and I think she ws correct.