B2M and plasma cell myeloma: A comprehensive study was performed to demonstrate the following myeloma-related parameters in all eligible patients: serum M-protein; full immunoglobulin and free light chain type; serum levels of beta-2-microglobulin (B2M), C reactive protein (CRP) and lactate dehydrogenase (LDH); bone marrow aspirate and biopsy to determine infiltration by plasma cells.