Squier1 has written an interesting and comprehensive review of the literature on the chemistry of pernicious anemia. Though a number of researches have been made on the pathochemistry of this very fatal disease, its causative factor is still unknown. Whether it is essentially a disease of the gastro-intestinal tract, with atrophy of the gastric mucosa and the absorption either of enterogenous poisons or protein split products, or whether it is a disturbance due to the hemolytic action of toxins elaborated in disease processes, or whether the disease is caused by hypersplenism, are the three main hypotheses in this mooted question.
The evidence brought forward by those authors who favor one or the other of these theories is not conclusive. A large number of chemical substances, such as oleic acid, saponins, phenylhydrazin, b-amino-azolyl-ethyl benzaldehyd, p-oxyphenylethylamin, etc., are violent hemolytic agents, and experimentally such poisons will produce anemia and hemoglobinuria, etc., but
KAHN M, BARSKY J. STUDIES OF THE CHEMISTRY OF PERNICIOUS ANEMIA. Arch Intern Med (Chic). 1919;23(3):334-345. doi:10.1001/archinte.1919.00090200067006