Two-dimensional immunolectrophoresis as a diagnostic tool for heavy chain disease

8 sera from patients with three types (gamma, alpha, mu) of heavy chain disease were tested by two-dimensional immunoelectrophoresis (Td. IEP) in order to assess the potential usefulness of such a technique as a routine diagnositc tool for heavy chain disease. Rocket immunoselection of the same sera was also performed by comparison. Characteristic, though not pathogomonic patterns were obtained by Td. IEP of the sera from patients with alpha chain disease. The main differential ciriteria by which heavy chain disease proteins could be differentiated from myeloma immunoglobulins were as follows: a) marked heterogeneity of the precipitin lines, ascribeable to the formation of polymers of different sizes; b) decreased sharpness, sometimes blurred delimitation, of the precipitin lines; c) frequent occurrence of spurs of the myeloma proteins over the deleted immunoglobulins in Kroll's tandeum variant, or between deleted immunoglobulins and small amounts of normal immunoglobulins present in the same serum. In our experience, rocket immunoselection does not show appreciable advantages as compared with Td. IEP.