Elevated Blood Lead Levels in Children With Sickle Cell Disease

BACKGROUND: Although prior reports suggest sickle cell disease (SCD) as a risk factor for lead poisoning, this association remains understudied. This paper assesses the relationship between SCD and elevated blood lead levels (BLLs) in New York City children. METHODS: We conducted a retrospective matched cohort study of children born in NYC from 2004 to 2016 and tested for BLLs from 2004 to 2022. Children with SCD were matched 1:2 to children without SCD based on maternal race and country of birth. Firth penalized-likelihood logistic regression estimated associations between SCD and BLLs ≥3.5, ≥5, ≥10, and ≥15 µg/dL, adjusting for Medicaid status, housing age, and maternal race. Additional analyses evaluated effect modification by age and SCD genotype. RESULTS: The cohort included 1463 children with SCD and 2982 without SCD. SCD was associated with lower odds of BLLs ≥3.5 µg/dL (odds ratio [OR] 0.81; 95% confidence interval [CI]: 0.66-0.99), no difference at ≥5 µg/dL (OR 0.86; 95% CI: 0.66-1.10), and higher odds at ≥10 µg/dL (OR 1.82; 95% CI: 1.06-3.13), with a similar estimate at ≥15 µg/dL (OR 2.23; 95% CI: 0.98-5.07). The SCD-by-age interaction was significant at ≥10 µg/dL (OR 4.47; 95% CI: 1.41-15.50), and children with HbSS had significantly higher odds of BLLs ≥10 µg/dL and BLLs ≥15 µg/dL than children without SCD (OR 2.25 and 2.98, respectively). CONCLUSION: Children with SCD have increased odds of elevated BLLs at higher thresholds, especially those aged ≥3 years and those with HbSS. Targeted rescreening of these children warrants consideration.