Simultaneous detection of diagnostic biomarkers of alkaptonuria, ornithine carbamoyltransferase deficiency, and neuroblastoma disease by high-performance liquid chromatography/tandem mass spectrometry

BackgroundUrinary homovanillic acid (HVA)/vanillylmandelic acid (VMA), orotic acid (OA), and homogentisic acid (HGA) are diagnostic biomarkers of neuroblastoma, ornithine carbamoyl transferase deficiency (OCTD), and alkaptonuria (AKU), respectively. In this study, a high-performance liquid chromatography–tandem mass spectrometry (LC–MS/MS) method was developed for simultaneous quantification of HVA, VMA, OA, and HGA in urine.MethodsAfter sample preparation, which involved only the dilution procedure, samples were quantified by LC–MS/MS. Full-scan MS/MS mode enabled the urinary markers to be quantified with a high degree of specificity and sensitivity. Rather than using a separate enzymatic method to normalize the concentration of creatinine in urine, we quantified the level of creatinine in urine in one LC–MS run.ResultsThe limits of detection were 10 μg/l for HGA, 25 μg/l for HVA/VMA, and 50 μg/l for OA with a single-to-noise ratio of 3; the limits of quantification were 50 μg/l for HVA and HGA, 100 μg/l for VMA, and 250 μg/l for OA. The linear dynamic range for quantification of the analytes covered 2 to 3 orders of magnitude, depending on the analyte. The relative standard deviation of the developed LC–MS/MS method was less than 4% for the intra-day validation and 10% for the inter-day validation.ConclusionsThe results show that our LC–MS/MS technique is a highly sensitive and rapid method for screening for biomarkers that are diagnostic of three metabolic diseases.

► This method allowed for the rapid screening of metabolites in urine from patients with alkaptonuria, OCTD, or neuroblastoma.
► The level of creatinine was quantified with LC/MS at the same time to normalize the urine sample differences.
► The creatinine and the metabolites in urine were quantified in one-run using LC/MS/MS.
► Sample preparation was simple which involved only the dilution procedure.