A retrospective study of the relative utility of electrophoresis, immunoelectrophoresis, immunofixation, and nephelometry in the investigation of serum proteins.

OBJECTIVES

To assess the relative value of visual inspection of protein electrophoresis patterns, immunoelectrophoresis, immunofixation, and specific protein quantitation in the investigation of serum proteins.

DESIGN AND METHODS

A retrospective study of protein results on 372 sera analyzed by electrophoresis and immunoelectrophoresis. A subsection of specimens (276) also had immunoglobulin quantitation by immunonephelometry and 30 were studied by immunofixation.

RESULTS

Total gamma globulin levels were correctly assessed visually in 84.4% of cases. Discrete bands seen visually were mainly monoclonal in 74 of 80 (92.5%). Six monoclonal proteins were not detected visually. Twenty-five monoclonal proteins required immunofixation for typing, and 60 were typed by immunoelectrophoresis. The visual assessment of the level of normal immunoglobulins in the presence of a monoclonal gammopathy was correct in 58% of cases.

CONCLUSIONS

The majority of monoclonal gammopathies could be evaluated by a combination of protein electrophoresis and immunoelectrophoresis. Except for quantitating monoclonal immunoglobins, protein electrophoresis was unreliable as a quantitative procedure and nephelometry was preferred.