MSACL 2026 Abstract

Improving Pediatric Dried Blood Spot Lead Screening Through Reduced Filter Paper Punch Diameter

Nathaniel Craun (1, 2), Michael Breckenridge (1), Mahesheema Ali (1, 2)
(1) Department of Pathology, MetroHealth Medical Center, Cleveland, OH, United States, (2) Case Western Reserve University School of Medicine, Cleveland, OH, United States

Nathaniel Craun, BS Biology (Presenter) Case Western Reserve University

Presenter Bio: Aspiring physician-scientist and student at Case Western Reserve University pursuing a Bachelor of Science in Biology and a Bachelor of Arts in Chemical Biology, with minors in Chemistry and Nutrition & Lifestyle Medicine. Research interests include clinical laboratory medicine, clinical chemistry, translational diagnostics, pathology, and immunology. Research experience includes pediatric blood lead screening, clinical assay evaluation, pancreatic enzyme assay interference, autoimmune disease diagnostics, HIV immunology, and skin fibrosis and lipodystrophy research. Passionate about developing and translating innovative laboratory diagnostics that improve patient care and public health.

Relevant Financial Disclosures (within past 24 months, reported on Jul 08, 2026) No relevant financial relationship(s) to disclose. Conflict mitigation NOT REQUIRED.

INTRODUCTION:
Childhood lead exposure remains a significant public health concern, as even low-level exposure can cause irreversible neurodevelopmental harm. Blood lead level (BLL) screening is therefore essential for early identification of at-risk children. Filter paper-based dried blood spot (DBS) testing offers a practical approach for large-scale pediatric BLL screening because it requires only a small capillary blood sample, avoids venipuncture, and permits low-cost collection during routine visits with centralized laboratory processing. However, specimens must adequately saturate the filter paper for testing, and insufficient samples are reported as quantity not sufficient (QNS). Because DBS screening is performed primarily in infants and toddlers, for whom specimen collection can be challenging, QNS rates may be substantial, making repeat collection burdensome for patients and families. In regions with older housing stock, such as Northeast Ohio, where lead exposure risk remains elevated, reducing QNS rates and improving specimen adequacy are important for effective population-based screening.

OBJECTIVES:
This study aimed to evaluate whether reducing the required filter paper collection diameter, thus lowering the blood volume needed to fully saturate each collection spot, improved specimen adequacy and decreased QNS rates in pediatric DBS collections. A secondary objective was to assess whether this change improved agreement between positive DBS screening results and confirmatory venous blood lead testing.

METHODS:
Pediatric filter paper BLL tests collected over a 13-month period were retrospectively reviewed to assess the effect of reducing the filter paper punch diameter from 8 mm to 6 mm on QNS rates, specimen adequacy, and DBS screening positivity. Blood lead concentrations were measured by electrothermal atomic absorption spectroscopy (ETAAS) using a graphite furnace atomic absorption spectrometer. For children with positive DBS screening results, confirmatory venous blood collection was attempted, and, when obtained, venous blood lead concentrations were analyzed using the same instrument.

RESULTS:
A total of 2,365 pediatric patients (mean age, 1.86 years) underwent filter paper blood lead level (BLL) screening during the 13-month study period. Before implementation of the reduced punch diameter (June 2025–March 2026; n = 1,545), the QNS rate was 8.67%, compared with 5.24% after implementation (April 2026–June 2026; n = 820), representing a 39.56% relative reduction. Among successfully processed specimens, 4.25% screened positive for elevated BLLs before implementation versus 3.90% after implementation. Among positive screening results with confirmatory venous testing, 75.76% were confirmed to have elevated BLLs before implementation, compared with 88.89% after implementation.

CONCLUSION:
Reducing the filter paper punch diameter from 8 mm to 6 mm was associated with a substantially lower QNS rate, no apparent increase in presumptive positive screening results, and fewer apparent false-positive screening results based on venous confirmatory testing, suggesting improved specimen adequacy while maintaining clinical screening performance for pediatric filter paper BLL testing. This simple, low-cost modification may represent a readily scalable approach to improving specimen adequacy and laboratory efficiency in pediatric BLL screening.