In this communication I shall attempt to answer the question as to whether or not native complement is increased in the blood serum in hyperthyroidism, and I shall discuss the relationship between the complement value as determined by hemolytic titration and the basal metabolic rate as determined by indirect calorimetry.
This study was suggested by the recent work of Hadjopoulos and Burbank1 on the rôle of complement in health and disease. These investigators demonstrated that complement varies considerably from the normal in the course of acute infections, and that this variation is of prognostic value. They found complement increased in hyperthyroidism and decreased in hypothyroidism: "Known pathologic conditions that give rise to high metabolism such as hyperthyroidism were also found by us to give a high complement titre while the reverse was found true in true hypothyroidism . . ." On the basis of this research, Hadjopoulos and Burbank proposed a new