An immunochemical evaluation for the identification and typing of monoclonal proteins

Using automated measurements of kappa (kappa) and lambda (lambda) light chain and IgG, IgA and IgM concentrations we assessed the ability of the kappa/lambda ratio and the heavy/light chain ratio to identify and type monoclonal components which had been previously identified by serum protein electrophoresis and immunoelectrophoresis. We examined 1151 samples, of which 277 contained monoclonal components; 90% of the monoclonal proteins could be identified by this approach, of which 95% were correctly typed. In addition 19 of 874 samples without monoclonal components showed an abnormal kappa/lambda ratio. We assessed the ability of the immunochemical evaluation to calculate monoclonal component concentration and then compared the results to the scanning densitometry of serum protein electrophoresis.