Evaluation of LeadCare Ultra® as an initial screen for elevated blood lead levels

Objective: The LeadCare Ultra® (LCU) was compared to inductively coupled plasma mass spectrometry ICP-MS for use as a screening test for elevated blood lead levels (BLLs) in capillary samples from children. Methods: During the validation, method comparisons between LCU and ICP-MS were analyzed to determine the bias above, near, and below the BLL cut-off of 5 μg/dL. Additionally, capillary samples that screened positive by LCU (above the 5 μg/dL cut-off) were compared to venous samples analyzed by ICP-MS for confirmatory testing. Results: LCU had a positive bias (1.7 μg/dL) below the cut-off of BLL <5 μg/dL, no bias near the cut-off from BLL 5–10 μg/dL, and a negative bias (−0.8 μg/dL) for BLL >10 μg/dL compared to ICP-MS. Of the 59 capillary samples that screened positive by LCU between May of 2017 to April of 2018, 19 were confirmed positive by ICP-MS, 30 were confirmed negative by ICP-MS, and 10 did not have a confirmed result. Conclusion: The LCU assay is an acceptable screen for capillary samples with the BLL cut-off of 5 μg/dL.