If no cause is identified, the term "monoclonal gammopathy of undetermined significance" is used.
These disorders are characterized by the presence of any abnormal protein that is involved in the immune system, which are most often immunoglobulins and are associated with the clonal proliferation of lymphocytes.
When a paraproteinemia is present in the blood, there will be a narrow band, or spike, in the serum protein electrophoresis because there will be an excess of production of one protein.
There are two large classes of blood proteins: albumin and globulin. They are generally equal in proportion, but albumin is much smaller than globulin, and slightly negatively charged, which leads to an accumulation at the end of the electrophoretic gel. The globulins separate out into three regions on the electrophoretic gel, which are the α band, the β band, and the γ band.