Related Experiment Videos
Need for the lead mobilization test in children with lead poisoning
1Department of Pediatrics, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, New York 10467.
Insights
The lead mobilization test (LMT) is recommended for children with blood lead levels (bPb) between 25-40 µg/dL. Children with bPb ≥ 40 µg/dL may skip the LMT and proceed to chelation therapy.
Area of Science:
- Pediatrics
- Environmental Health
- Toxicology
Background:
- The Centers for Disease Control (CDC) recommends the lead mobilization test (LMT) for children with moderate lead poisoning.
- Current eligibility criteria for LMT include blood lead (Pb) levels between 25-55 µg/dL and erythrocyte protoporphyrin > 35 µg/dL.
Purpose of the Study:
- To refine eligibility criteria for the LMT in children with moderate lead poisoning.
- To assess the utility of current criteria in identifying children who would benefit from chelation therapy.
Main Methods:
- Compared blood lead (Pb) levels on the day of LMT with test results in 198 children.
- Analyzed lead excretion following a test dose of calcium disodium ethylenediamine tetraacetate.
Main Results:
- Children with bPb < 25 µg/dL showed minimal lead excretion (24/25 patients).
- Children with bPb ≥ 40 µg/dL had an 88% likelihood of excreting sufficient lead to warrant chelation.
- LMT is indicated for children with bPb levels between 25-40 µg/dL.
Conclusions:
- The LMT is most beneficial for children with bPb levels between 25 and 40 µg/dL.
- For children with bPb between 40-55 µg/dL, chelation therapy may be initiated without LMT if impractical.
- Children with bPb < 25 µg/dL require clinical monitoring and removal from lead exposure.
Abstract:
We evaluated the recommendation of the Centers for Disease Control, that children with moderate lead poisoning undergo the lead mobilization test (LMT) to determine the need for a full course of chelation treatment. Current criteria for selection for this test include a blood Pb concentration (bPb) between 25 and 55 micrograms/dl and an erythrocyte protoporphyrin level greater than 35 micrograms/dl. To determine whether the eligibility criteria could be refined to a smaller group of patients, we compared bPb determinations obtained on the day of the LMT in 198 children with moderate Pb poisoning to the results of the LMT. We found that children with bPb less than 25 micrograms/dl were unlikely to respond to the test dose of calcium disodium ethylenediamine tetraacetate with a Pb diuresis (24/25 patients had low urinary Pb excretion on the LMT). In contrast, 88% of children with bPb greater than or equal to 40 micrograms/dl were likely to excrete sufficient Pb to indicate the need for a full course of chelation. We conclude that the LMT is indicated for children with bPbs between 25 and 40 micrograms/dl. Children with bPb between 40 and 55 micrograms/dl may receive chelation therapy without having an LMT, if the performance of the LMT is not practical. Patients with levels less than 25 micrograms/dl should be followed clinically and removed from further Pb exposure.