BACKGROUND: Discovered in 1938, haptoglobin is a liver-produced α2-glycoprotein that binds free hemoglobin, mitigating its toxic effects, and serves as a biomarker for hemolysis. The current study, under the HAPPI Kids initiative, aimed to define paediatric reference intervals for haptoglobin through the collection of samples from healthy children and neonates, with the overall aim to improve diagnostic accuracy in young patients. METHODS: Blood was collected from 335 children aged 30 days to 18 years and 20 neonates from February 2015 through December 2016. Samples were analysed on 3 automated analysers: a) Roche Cobas c501/c502, b) Roche Cobas c701, and c) Beckman Coulter Unicel DXL 600/800. RESULTS: Age and sex specific haptoglobin reference ranges were reported with a 95% confidence interval. CONCLUSION: We report continuous age-specific reference intervals for serum haptoglobin in neonates and children. The data suggests that haptoglobin levels have limited clinical value in children under 13-15 years, as they are often naturally low and may fall below the assay detection threshold.
Maamari et al. (Tue,) studied this question.