In 1908, Kocher1 pointed out that the differential formula in cases in which patients were suffering from exophthalmic goiter might be abnormal, showing a preponderance of lymphocytic elements. He thought that this relative lymphocytosis represented an index of the severity of the disease. In a recent communication,2 I reported on the production of a relative mononucleosis in normal animals, occurring after a period of excitement lasting from ten to fifteen minutes. This emotional relative mononucleosis was evidently connected with sympathetic activation of lymphoid structures, particularly the spleen, for it was shown that removal of the sympathetic strands in an animal, splenectomy, or merely denervation of the spleen could inhibit this physiologic increase in the relative mononuclear counts after excitement.
The present clinical study was undertaken in order to ascertain the incidence of relative lymphocytosis in cases of hyperthyroidism, and also the character of the differential formula in patients