Assessment of LeadCare® II analysis for testing of a wide range of blood lead levels in comparison with ICP-MS analysis.

ABSTRACT

The LeadCare® testing system, which utilizes anodic stripping voltammetry (ASV) methodology, has been widely used worldwide for cost-effective blood lead level (BLL) screening. However, some concerns have recently been issued regarding inaccurate results obtained using LeadCare®. Hence, we aimed to evaluate the accuracy of BLL measured by LeadCare® II (BLLLC) by comparison with ICP-MS (BLLIM) by the Passing-Bablok regression, Deming regression, and Bland-Altman analyses by using 994 venous blood samples. BLLLC ranged from 3.3 to 162.3 µg/dL, while BLLIM ranged from 0.8 to 154.8 µg/dL. Although BLLLC and BLLIM exhibited a strong and positive correlation, BLLLC values were generally greater than BLLIM values, indicative of the overestimation of the LeadCare® analysis. A large positive bias of 19.15 ± 8.26 µg/dL and 29.25 ± 14.04 µg/dL for BLLLC compared with BLLIM were recorded in the BLLLC range of 45.0-64.9 µg/dL and for ≥65.0 µg/dL, respectively. In contrast, a bias of ≤0.3 µg/dL was observed at a BLLLC of less than 10.0 µg/dL. Blood copper, cadmium, and iron levels did not exhibit an effect on the bias of BLLLC, indicative of the minimal potential interferences of the metals; these interferences are a cause for concern with the ASV method. In conclusion, LeadCare® analysis is thought to be a good tool for screening purposes at a lower BLL around the reference level of 5 µg/dL in the initial stage; however, conversion or retesting using a laboratory analyzer is recommended at a higher BLL for appropriate clinical evaluation and research.