Is there an absolute IgM level, in an asymptomatic patient on surveillance that initiation of therapy would be considered for Waldenstrom's macroglobulinemia?  

The rate of progression of a paraprotein in a plasma cell disorder or LPL is always concerning, but it's not enough to bring about action. That said, we clinicians are always looking for bad behavior by cancer cells -- these are the indications for treatment more than the rate of rise or attain...