Interprétation délicate de l'immunofixation des protéines sériques

Immunofixation is currently very used in medical laboratories. The interpretation of the results is usually easy, but some cases raise interpretative problems. We here report two cases difficult to interpret. In the first case, we report a case of nonspecific precipitation of the protein on each track, in the second case we report a case of double monoclonal band on immunofixation electrophoresis. Reducing agent such as β2-mercaptoethanol used in these two cases allowed to solve the problem and to make a diagnosis. A comparison between clinical radiological and laboratory test data is necessary before making a diagnosis of monoclonal immunoglobulin.