[Light chain typing of paraproteins and Bence-Jones proteins by immunoelectrophoresis]

Light chain types of paraproteins G (76), A (28) and D (5), monoclonal macroglobulins (14) and Bence-Jones proteins (11) were determined by immunoelectrophoretic analysis using monospecific antisera to surface (accessible) and nonaccessible determinants of light chains. The types of the G and A paraproteins were determined in the whole sera; D paraproteins and monoclonal macroglobulins were purified before typing. No precipitation occurred with antisera to light chains in 6 out of 28 A paraproteins. In these cases the inhibition of the IgG precipitation with either the anti-kappa or anti-lambda sera allowed to determine the paraprotein type. The kappa:lambda ratio was established for paraproteins of various classes: 1.7 for paraproteins G, 1.0 for paraproteins A, 2.5 for monoclonal macroglobulins and 0.83 for Bence-Jones proteins. All the D paraproteins investigated were of the lambds-type.