Novel urine hepcidin assay by mass spectrometry

The hepatic peptide hormone hepcidin is the central regulator of iron metabolism and mediator of anemia of inflammation. To date, only one specific immuno-dot assay to measure hepcidin in urine had been documented. Here we report an alternative approach for quantification of hepcidin in urine by surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF-MS). Peptide peaks were detected corresponding to the 3 forms of hepcidin normally found in urine. The identity of the peptide peak equivalent to hepcidin-25 was confirmed using synthetic human hepcidin-25. Validation of our MS data on samples with various hepcidin levels showed a strong correlation with previous immuno-dot assay results (Spearman R = 0.9275, P < .001). Most importantly, this hepcidin assay clearly discriminates between relevant clinical iron disorders. In conclusion, this novel MS urine hepcidin assay is easy to perform and available to a wide audience. This enables the implementation of hepcidin measurements in large clinical studies.