Quantification of glutaric and 3-hydroxyglutaric acids in urine of glutaric acidemia type I patients by HPLC with intramolecular excimer-forming fluorescence derivatization

dBackground: Glutaric aciduria type I (GA1) is an autosomal recessive disorder that usually causes neurological damage. Early diagnosis of the disease prior to the appearance of clinical symptoms can lead to better outcomes. Methods: We describe a simple and selective HPLC method with intramolecular excimer-forming fluorescence derivatization to diagnose GAL Glutaric acid (GA) and 3-hydroxyglutaric acid (3HGA) in urine and an internal standard were derivatized with I-pyrenebutyric hydrazide (PBH). The derivatives were separated on a C-18 column and fluorometrically detected at 475 nm (excitation of 345 nm) with a run time of 18 min. Results: Excellent linearity over a wide range, reproducibility (coefficient of variation <= 14.5%), and sensitivity (limit of detection 0.4 mu mol/l 3HGA and 0.2 mu mol/l GA) were obtained. A retrospective study on previously diagnosed GA1 patients' urine from our laboratory archives between 1999 and 2004 was performed by analysts blinded to the study. Conclusions: The method enabled us to differentiate GA I cases (n =36) from controls (n =99), regardless of the years of urine storage. The method is valuable for both retrospective and prospective diagnoses of GA1. (c) 2005 Elsevier B.V. All rights reserved.