Abstract: The present invention relates to methods and compositions for the diagnosis, treatment, management, or prevention of plasma cell disorders, including systemic light-chain amyloidosis (AL) and multiple myeloma (MM). In particular, the invention encompasses the use of anti-CD32B antibodies, analogs, derivatives or fragments thereof, or compounds or agents that bind to CD32B and modulate CD32B activity in the plasma cells of mammals. The invention also encompasses the use of anti-CD32B antibodies, analogs, derivatives or fragments thereof, or CD32B binding compounds or agents in combination with or in addition to other cancer therapies for the treatment, prevention, management, or amelioration of a plasma cell disorder characterized by the expression of CD32B, or one or more symptoms thereof.