Ivig and Imuran ?

Hey all . I posted up here a few weeks back regarding Necrotizing myositis Srp positive and Imuran . Ck levels are down tremendously from 2500 to 187 currently. That’s still on 40 mg of prednisone and 100 mg of Imuran which i will increase to 150 in a few days to try and taper off prednisone . Both my Nuerologist and Rheumatologist are suggesting adding ivig . I continue to have left sided chest and joint pain that interferes w my life daily 😫 scary .. I just wanted to see if anyone on here has had any experience w any of this .. it all seems like a lot so fast :( I’ve been reading on ivig and nervous about side effects .

Any stories experiences or input would be appreciated:) Back story .. completely healthy 43 year old female . Not one health issue before now . So it’s kinda tough . Thank you !