Biomarker analysis for APRT deficiency diagnosis using UPLC-MS/MS

Adenine phosphoribosyltransferase (APRT) deficiency is a rare genetic disorder. Since activity of the APRT enzyme is absent, adenine is oxidized and forms 2,8-dihydroxyadenine (DHA). DHA is insoluble in urine and can precipitate and form kidney stones, which can cause acute and chronic kidney failure. The disease can be treated with the drugs allopurinol and febuxostat, which prevent the conversion of adenine to DHA and thus reduce formation of kidney stones in APRT deficiency patients. UPLC-MS/MS method for simultaneous quantification of DHA, adenine and the drugs, allopurinol, oxypurinol and febuxostat in human plasma had been developed. The objective of this study was to perform full validation of the UPLC-MS/MS quantification method according to method validation guideline from Food and Drug Administration (FDA Bioanalytical Method Validation Guidance for Industry, 2018). Following full validation of the UPLC-MS/MS method, plasma samples from patients with APRT deficiency will be studied. The sample preparation procedure was optimized prior to conductance of full validation of the UPLC-MS/MS quantification method. During the validation process, the performance of the analytical column changed, shown by a deterioration of chromatographic peak shape of the analytes and increased column pressure. Therefore, investigation of different batches of analytical columns was conducted and the results indicated that column properties changed following analysis of human plasma extracts. It was concluded that further investigation of this phenomena is needed before conducting the full validation procedure. However, due to COVID-19 epidemic the laboratory was temporarily closed before the issue could be resolved and no further work could be conducted.

Author dc:creator

• Pálmi Þorgeirsson 1992-

Contributors dc:contributor

• Háskóli Íslands

• Lyfjafræði
• Erfðasjúkdómar
• Lyfjameðferð

Language dc:language.iso

en

Handle dc:identifier.uri

http://hdl.handle.net/1946/35098

OAI identifier oai:identifier

oai:skemman.is:1946/35098