THE EXCRETION OF PORPHYRIN IN REFRACTORY AND APLASTIC ANEMIA.

Technical procedures which have been developed for quantitative measurements of the rate of excretion of the porphyrins have advanced the knowledge of the fundamental nature of certain anemic states. By such studies the disorders of hematopoiesis may be divided into two major groups on a pathological-physiological basis. In one group the metabolism of the pigments is quantitatively increased but is normal in type. Pernicious anemia, congenital hemolytic jaundice, and the anemia caused by phenylhydrazine are all of this variety (1, 2, 3, 4, 5). In a second group, however, a qualitative as well as a quantitative deviation from the normal metabolism of pigments exists. The anemia of lead (6, 7, 8) and salvarsan poisoning (9), and of certain hepatic cirrhoses, notably hemachromatosis, are of this type (1, 10). Recent advances in the treatment of pernicious anemia and the anemias of a deficiency of iron and copper have made prominent a group of blood dyscrasias which does not respond to the administration of liver extract or of iron. Cases of this type which are apparently primary are termed aplastic, aregenerative or achrestic anemia, and compose a group of general as well as of physiological interest. The cause of primary aplastic anemia is obscure in most instances, although certain cases are encountered in which exposure to benzol, gold, or arsphenamine seems to have been etiological. Histological study of the hematopoietic bone marrow in these toxic cases shows no consistent difference from the lesions in patients clinically similar but who give no history of exposure to potentially toxic compounds. Aplastic anemia is, then, therapeutically unlike pernicious anemia or the microcytic anemias, and certain cases seem to be toxic in origin. Studies of the metabolism of the pigments in cases of aplastic anemia should establish conclusively whether the underlying physiological disturbance is like that of the deficiency or of the toxic group. In the course of a study of refractory anemia, detailed observations of the metabolism of pigments have been made in six patients. Studies of one such case have been reported by Brugsch (11). The cases were selected to represent as closely as possible the different subgroups into which aplastic anemia may be divided (12). To render the rationale of this study and the validity of the results intelligible, the brief review by Dobriner and Rhoads of the chemistry of the porphyrins should be consulted (13).