Pernicious anemia. A clinical study of 5 cases with special reference to morphological abnormalities, gastric secretion and autoantibodies

Five cases of pernicious anemia are described. The diagnosis was based on the following criteria: (1) a megaloblastic marrow that responded to parenteral vitamin B₁₂ therapy, (2) an abnormal Schilling test that corrected on repetition with intrinsic factor, (3) gastric achlorhydria after tetragastrin stimulation as well as severe gastric atrophy shown from fundal biopsy. Special emphasis was put on the analysis of morphological abnormalities, gastric secretion and autoantibodies. All the marrow specimens showed characteristic megaloblastic change. Erythrophagocytosis was usually found. In addition, 3 types of degenerating megaloblasts were observed: (1) nucleus appearing vacuous, (2) multiple vacuoles in the cytoplasm, and (3) indistinct and smudged nucleus with poor cytoplasmic details. These abnormalities and erythrophagocytosis provide cytological evidence for intramedullary hemolysis and ineffective erythropoiesis. The Prussian blue reagent demonstrated coarse ringed sideroblastic granules in all 5 cases, which reflects the abnormalities of iron metbolism. All patients had gastric atrophy, achlorhydria and markedly elevated fasting serum gastrin levels. Gastric parietal cell antibodies were present in 4 cases using the indirect immunofluorescent method. One was positive for both thyroglobulin and thyroid microsomal antibodies, and another had antimicrosomal antibodies. The significance of the presence of autoantibodies and their relation to the pathogenesis of pernicious anemia are discussed.