Validation of an Enzyme-Linked Immunosorbent Assay for Measuring Leptin, a Key Metabolic Hormone, in Dried Blood Spot Samples #MMPMID41346082
Kim EY; Orozco LS; Shoemaker EG; Gassen J; Nowak TJ; Weaver SP; Baker EJ; Muehlenbein MP; Urlacher SS
Am J Hum Biol 2025[Dec]; 37 (12): e70172 PMID41346082show ga
OBJECTIVES: Leptin is an established biomarker of appetite regulation and energy status. Problematically, heavy reliance on invasive venipuncture sampling has limited leptin research with diverse human populations and groups such as children. Key questions remain about leptin's evolution and biological roles across the full range of humans. Here, we present and validate a new minimally invasive approach for measuring leptin in finger-prick dried blood spots (DBS) using a commercial ELISA kit. METHODS: The Human Leptin Quantikine QuicKit ELISA (R&D Systems, QK398) was validated using matched serum and DBS samples from 40 adults. Passing-Bablok regression assessed the relationship between leptin(DBS) and leptin(serum). Dilutional linearity, reliability, spike-and-recovery, limit of detection, and stability tests evaluated assay performance and potential DBS matrix interference. RESULTS: Leptin was reliably measured in all DBS samples (average = 312 pg/mL), with DBS intra- and inter-assay CVs of 3.3% and 2.0%, respectively. Matched leptin(DBS) and leptin(serum) measurements showed excellent agreement (Pearson's R = 0.97), with no apparent bias (Bland-Altman bias = 4.7). Leptin measurement in DBS was stable for at least 72 h at 26.2 degrees C and 37 degrees C and showed no degradation across eight freeze-thaw cycles (p > 0.05). CONCLUSIONS: Leptin can be reliably and stably measured in minimally invasive DBS samples, expanding research on energetics and appetite regulation across a wider range of human groups and settings.
Am+J+Hum+Biol 2025 ; 37 (12): e70172
