A spectrophotometric method for determining the phenotype of acetylation based on caffeine metabolism

Justifiation. The multiplicity of diseases and conditions in which NAT2 plays a key role, dictates the need to study both the genotype and the phenotype of acetylation. Such approaches will make it possible to identify risk groups, as well as select effective doses of drugs, preventing the development of side effects and determining the optimal therapeutic dose.

Methods. The work was performed in a group of 52 patients with spinal canal stenosis (average age 51.04 ± 9.671 years) and 32 conditionally healthy people (average age 53.32 ± 0.933 years). Creatinine and uric acid were determined in blood and urine samples before and after taking caffeine, and the optical density of urine at 272 nm was measured. To estimate the acetylation rate, the calculation of an integral predictive indicator is proposed. PCR with specific primers was used as a reference method to detect NAT2 polymorphisms affecting the acetylation rate.

Results. An effective, easily executable algorithm has been developed that includes the technology of collecting, preparing and analyzing blood and urine samples before and after using caffeine as a test drug, and calculating an integral predictive indicator to assess the rate of acetylation reactions. The method is suitable for indirect, simpler and less costly assessment of the rate of acetylation reactions compared with molecular genetic studies.

Conclusion. The determination of the acetylation phenotype using the proposed analytical procedures makes it possible to identify individual differences in connective tissue metabolism, and to seek approaches to predicting treatment outcomes depending on the polymorphic variant of NAT2 with the identification of risk groups. The data obtained can be used to search for new links in pathogenesis, to implement the mechanisms of pain and fibrosis.

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