Increases in serum γ-globulin above normal levels are common. They occur in a large variety of conditions 1 and are divided on the basis of paper electrophoresis into "narrow band" and "diffuse" types.2 Narrow band aggregates of protein, traveling in the γ-zone, are known as "Myeloma" or "M" type proteins. They are most frequently seen in association with multiple myeloma3 although they have been reported in a number of other conditions 4 and in one apparently normal blood donor.5
Once abnormal protein bands have developed, they almost invariably persist. Osserman,6 describing 24 patients with narrow band γ-globulin elevation, states that in no instance did the abnormal protein diminish in concentration or disappear. Waldenstrom,3 in an extensive review of patients with hypergammaglobulinemia of the narrow band type, found no instance of reversion to normality.
This paper describes a patient with proven hyperthyroidism whose serum proteins on