CIDP with antiMAG IgM

I have also been diagnosed MGUS-antiMAG (IgG????). am I missing something here or is this a completely different animal? Have tried steroids and IVIG with minimal results but everytime I mention rituxan to my neurologist he frowns and changes the subject. Has rituxan been shown to only be effective with IgM? The literature and studies I have found seem to indicate this. Answer anyone please?
Let me add my three cheers for Dragon Naturally Speaking. It and my 3wpm hunt and pick pencil allow me to stay in touch even though my hands and feet are almost completely numb.
Thanks. Morris