M protein estimation
The levels of monoclonal protein were important in the diagnosis and assessment of efficiency, so serum protein electrophoresis (SPE), immunofixed electrophoresis (IFE), serum free light chain quantification, urine light chain quantification and 24 h urine M protein quantification were used for M protein estimation. M protein type of IgG, IgA, IgM, IgD, IgE, λ or κ was identified by immunofixation electrophoresis (IFE). The M protein levels of the patients were examined every two cycles, and the change of M protein level was used to judge the therapeutic effect.According to IMWG,