[Postgastrectomy megaloblastic anemia--possible participation of anti-intrinsic factor antibody in its pathogenesis--report of a case].
A case of 78-year old man with megaloblastic anemia occurring 20 years after partial gastrectomy is reported. Since about 2 years earlier he had an episode of convulsion, and he had been on anti-convulsants (diphenylhydantion, phenobarbital) until admission. Physical examination revealed a pale lean man with polyneuropathy and mental impairment. Laboratory findings revealed WBC 3100/microliters, RBC 187 X 10(4)/microliters, HB 7.9 g/dl, MCV 124.4 microns3, MCH 42.7 micrograms, platelet counts 15.7 X 10(4)/microliters, serum vitamin B12 (VB12) 380 pg/ml, and serum folic acid 5.1 ng/ml. Serum autoantibodies to intrinsic factor (IF) and parietal cells were positive. Bone marrow examination revealed erythroid hyperplasia and megaloblastic changes. Schilling test revealed impaired absorption of VB12 with or without IF, but X-ray study of the small bowels was unremarkable. Treatment with intramuscular cyanocobalamin resulted in a rapid clinical improvement. A repeat Schilling test after 4 months of therapy showed a normal VB12 absorption in the presence of IF. These findings suggest that VB12 malabsorption of the 1st Schilling test was due to intestinal dysfunction caused by the VB12 deficiency state itself, and the improvement of VB12 absorption with IF after therapy suggests a pathogenesis similar to pernicious anemia in this patient.
Sugimoto
M
M
Department of Internal Medicine, Juntendo University School of Medicine.
Iesaki
T
T
Wakabayashi
Y
Y
Adachi
Y
Y
Hirose
S
S
D000368:Aged; D000748:Anemia, Macrocytic / Q000209:etiology*; D000749:Anemia, Megaloblastic / Q000209:etiology* / Q000276:immunology; D001323:Autoantibodies / Q000032:analysis*; D005743:Gastrectomy / Q000009:adverse effects*; D006801:Humans; D007437:Intrinsic Factor / Q000276:immunology*; D008297:Male; D011183:Postoperative Complications; D012546:Schilling Test; D014805:Vitamin B 12 / Q000097:blood
D001323:Autoantibodies; D007437:Intrinsic Factor; D014805:Vitamin B 12