American Journal of Clinical Nutrition, Vol 23, 147-155, Copyright © 1970 by The American Society for Clinical Nutrition, Inc.

Resolution of Ineffective Erythropoiesis of Pernicious Anemia and "Strongly Suggestive" Folate Lack in Response to Folic Acid

¹ From the Hematology-Oncology Section, Department of Medicine, Wilford Hall USAF Medical Center (AFSC), Lackland Air Force Base, Texas 78236

A patient with Addisonian pernicious anemia and "strongly suggestive" folate lack underwent an evaluation of the transformation from ineffective to effective erythropoiesis during a titration with pteroylglutamic acid. Repeated studies of serum lactic dehydrogenase, bilirubin, haptoglobin, reticulocytes, bone marrow, and endogenous carbon monoxide-derived fractional destruction rate and total hemoglobin mass provided a precise definition of the sequence of events during the experiment. Following a 14-day control period on a low folate diet, daily parenteral pteroylglutamic acid was given with weekly increments. The minimal dose resulting in hematologic response was 300 µg of pteroylglutamic acid daily, although there was evidence of continued ineffective erythropoiesis. At 1,000 µg/day there was a maximum reticulocyte response promptly followed by complete resolution of ineffective erythropoiesis. These data are compatible with the hypothesis that 1,000 µg pteroylglutamic acid/day was the optimum dose for the transformation of ineffective to effective erythropoiesis in a patient with classical pernicious anemia and "strongly suggestive" folate lack with no evidence of exaggerated folate consumption.

From day 40, when the initial hematologic changes began, to day 71 when ineffective erythropoiesis had stopped, there was a gradual transition from ineffective to effective erythropoiesis by all parameters measured. One could reasonably have expected this 31-day transition to have been shortened to 14-17 days had the "optimum dose" of 1,000 µg/day been given from the outset.