My mother is suffering from MM. Past history mild heart attack 10 yrs ago. When her hemoglobin drops below 8.8 she has many angina attacks (chest pain where she takes nitro pills). In our observation in taking care of her she needs blood transfusions at 8.8. My mothers IGG started at 3500 and after chemo twice dropped to 2600. Had her treatment switched to thalidomide and her IGG is now in the normal range below 1600 (hers is 1375). She is feeling much better now. She is still very tired all the time. Thalidomide will make a person tired due to the fact it works something like an anesthetic, but if taken before bed, a person will sleep better. No bad side effects with this drug either.