ESI-MS/MS를 이용한 소변 중 Globotriaosylceramide(Gb3)의 정량 및 임상 응용; 패브리병(Fabry) 진단

Method Development for the Profiling Analysis of Urine Globotriaosylceramide (Gb3) for the Screening of Fabry Disease by Tandem Mass Spectrometry

Measurement of globotriaosylceramide (Gb3, ceramide trihexoside) in urine has clinical importance for monitoring after enzyme replacement therapy in Fabry disease patients. The disease is an X-linked lipid storage disorder that results from a deficiency of the enzyme α-galactosidase A (α-Gal A). The lack of α-Gal A causes an intracellular accumulation of glycosphingolipids, mainly Gb3. A simple, rapid, and highly sensitive analytical method for Gb3 in urine was developed without labor-extensive pre-treatment by electrospray ionization MS/MS (ESI-MS/MS). Only simple 5-fold dilution of urine is necessary for the extraction and isolation of Gb3 in urine. Gb3 in diluted urine was dissolved in dioxane containing C17:0 Gb3 as an internal standard. After centrifugation it was directly injected and analyzed through guard column by in combination with multiple reaction monitoring mode of ESI-MS/MS. Eight isoforms of Gb3 were completely resolved from urine matrix. C24:0 Gb3 occupied 50% of total Gb3 as a major component in urine. Linear relationship for Gb3 isoforms was found in the rage of 0.005~5.0㎍/㎖. The limit of detection (S/N=5) was 0.005㎍/㎖ and limit of quantification was 0.05㎍/㎖ for C24:0 Gb3 with acceptable precision and accuracy. Correlation coefficient of calibration curves for 8 Gb3 isoforms ranged from 0.9598 to 0.9975. This method could be useful for rapid and sensitive 1st line Fabry disease screening, monitoring and/or diagnostic tool for Fabry disease.