Abstract
Serum folic acid clearance curves using Lactobacillus casei were determined on 10 normal individuals, 5 patients with hemolytic anemias and active hemolysis, 15 patients with myeloid metaplasia, and 12 patients with miscellaneous hematologic disorders.
In general, there was a correlation between the initial serum folate value and the subsequent serum folate clearance curve. Both values were determined by L. casei. In many instances of initial serum folate values classified as indeterminate, the serum folate clearance clarified the initial impression.
Patients with active hemolytic anemia showed rapid folate clearance curves following injection with a test dose of folic acid. In eight of 15 patients with myeloid metaplasia, the serum folate clearance was rapid; in 5 of these patients the serum folate clearance was consistent with marked folic acid deficiency. Several possible mechanisms for the folic acid deficiency in myeloid metaplasia are discussed, but the cause of the deficiency has not been established.