September 1972

Comparative Tests for Diagnosis of Lead Poisoning

Author Affiliations

Birmingham, Ala

From the Department of Medicine, University of Alabama School of Medicine (Dr. Morgan), and Trace Metals Research Laboratory, Veterans Administration Hospital (Mrs. Burch), Birmingham, Ala.

Arch Intern Med. 1972;130(3):335-340. doi:10.1001/archinte.1972.03650030019005

The level of erythrocyte enzyme delta-aminolevulinic acid dehydratase (ALA-D) has been determined in conjunction with other standard tests for lead poisoning. The mean for 53 healthy persons was previously shown to be 175 ±38 units. Lead excretion rates above 1.0 mg/24 hr in response to 1 gm of edetate disodium calcium (Calcium Disodium Versenate) given intravenously were associated with depression of the enzyme activity to 60 units or less. Enzyme activity was maximally depressed when lead excretion exceeded 2 mg/24 hr. Activity of ALA-D was more sensitive and accurate in the diagnosis of lead poisoning than urinary ALA or coproporphyrin excretion and as good as blood or urine lead determinations. Activity of ALA-D is rapidly restored toward normal by treatment with edetate disodium calcium.