This is a *vastly* simplified breakdown of how remission probably works in essential cryo.
The cryoglobulin is both an antigen AND an antibody. Cryoglobulins are produced on the surface of B cells that apparently have matured past the usual age at which they are programmed to die. In essence, the immune system wakes up due to an inflammatory process, and promptly attacks itself. This process never ends because the T cells remember to tell the immune system to make the cryoglobulins as a response to the activity. Using immunosuppressants tend to kill off fast growing cells such as B cells and T cells. The B cells are the cryo factory, and the T cells are the memory of what to attack. The thinking is, that if you suppress the immune system deeply, for a long enough period to eliminate the cryoglobulins, the T cells sometimes eventually “forget” about cryoglobulins altogether, and you have a “true” remission that can often be maintained for long periods after the immunosuppressant is withdrawn (typically withdrawn slowly, over the period of a year or more). In a very, very few cases, the cryo never comes back.
Short term remission is a bit different. The cryo is gone because the immunosuppression has killed off the B cells. As soon as the body generates a new batch of B cells , a flare is likely. This can be anywhere from a few days to a few weeks after withdrawing the immunosuppresant.