Andrew Arthur Arthur Wood, Sophie Rothwell Mason, Anna Frances Robson
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引用次数: 0
Abstract
Background Thiopurine metabolites, 6-thioguanine (6TG) and 6-methylmercaptopurine (6MMP), are monitored to aid therapeutic management of thiopurine drugs. At Manchester University NHS Foundation Trust (MFT), thiopurine metabolites are measured by high performance liquid chromatography with ultraviolet detection (HPLC-UV). Whole blood samples are lysed and subjected to hydrolysis with derivatisation of 6MMP before HPLC-UV detection at 304nm for the 6MMP-derivative and 342nm for 6TG. For some samples, 6MMP cannot be reported due to a chromatographic interference at 304nm co-eluting with the 6MMP peak. An investigation was performed to identify the interfering compound. Methods Patient medication histories were examined to identify candidate compounds for the interference. Candidate compounds were spiked into blood at supraphysiological concentrations and tested on the assay. Results Metronidazole was identified as being prescribed to all patients whose samples demonstrated the interference. Metronidazole and its metabolite, hydroxymetronidazole, were spiked into blood. HPLC-UV analysis of spiked blood demonstrated similar UV absorbance patterns to those seen in patient samples with the interference. Hydroxymetronidazole co-eluted with 6MMP causing interference in the measurement. Conclusion Metronidazole and its major metabolite can interfere with 6MMP measurement by HPLC-UV analysis at 304 nm.
期刊介绍:
Annals of Clinical Biochemistry is the fully peer reviewed international journal of the Association for Clinical Biochemistry and Laboratory Medicine.
Annals of Clinical Biochemistry accepts papers that contribute to knowledge in all fields of laboratory medicine, especially those pertaining to the understanding, diagnosis and treatment of human disease. It publishes papers on clinical biochemistry, clinical audit, metabolic medicine, immunology, genetics, biotechnology, haematology, microbiology, computing and management where they have both biochemical and clinical relevance. Papers describing evaluation or implementation of commercial reagent kits or the performance of new analysers require substantial original information. Unless of exceptional interest and novelty, studies dealing with the redox status in various diseases are not generally considered within the journal''s scope. Studies documenting the association of single nucleotide polymorphisms (SNPs) with particular phenotypes will not normally be considered, given the greater strength of genome wide association studies (GWAS). Research undertaken in non-human animals will not be considered for publication in the Annals.
Annals of Clinical Biochemistry is also the official journal of NVKC (de Nederlandse Vereniging voor Klinische Chemie) and JSCC (Japan Society of Clinical Chemistry).