Analysis of Protein Markers in Plasma of Patients with Drug Dependence Syndrome: Observational Clinical Study

Background. In drug addiction treatment, the diagnostic process is based on the chemical toxicological determination of the intoxication substrate or its metabolite. Laboratory monitoring and prediction issues that could form the basis of secondary prevention remain unresolved. Specific nervous tissue proteins are considered to be the most promising laboratory markers of drug pathology.Objective — to determine some potential biomarkers of protein-chemical nature in the plasma of patients with drug dependence syndrome.Methods. The study was conducted according to the design of an observational clinical trial at the Narcological Dispensary of Krasnodar Krai in the period from 07.2021 to 07.2022. The main group (group 2) included 31 patients diagnosed with substance dependence syndrome. The control group (group 1, n = 15) consisted of healthy subjects submitted to occupational medical examinations. During the detoxification-stabilization therapy and rehabilitation, 5 proteins were determined in the plasma: brainand glial-derived neurotrophic factors, neuron-specific enolase, alpha-synuclein and calcium-binding protein S100B. Statistical analysis of the data involved the Mann-Whitney test for comparing the values of the control and experimental groups and the Wilcoxon test for comparing the values of one group obtained at different stages of observation. The calculations were carried out using StatPlus version 7 (AnalystSoft Inc., USA).Results. A total of 31 patients were included in the main group, 18 of them were followed up with a diagnosis of opioid dependence syndrome (n = 11) or psychostimulant dependence syndrome (n = 7). Patients dropped out of the study due to their refusal to participate in the study or undergo rehabilitation, or due to relapse of the disease. When admitted to the hospital, patients indicated a 45% decrease in brain-derived neurotrophic factor in the plasma ( p < 0.001), and a 3.9-fold decrease after rehabilitation course ( p < 0.001). Glial-derived neurotrophic factor in the plasma exceeded the controls 1.9 times ( p < 0.001) upon admission to hospital, but rapidly returned to normal values thereafter. Level of neuron-specific enolase in the plasma was also poor, 36% lower than the controls ( p <0.001), but approached the control values by the end of rehabilitation.Conclusion. The study obtained data indicating the changes in neurotrophic factors in the blood plasma of patients with opioid or psychostimulant dependence. The rehabilitation period was marked by a relatively rapid improving level of neurotrophins; however, brain-derived neurotrophic factor remained reduced despite the successful treatment, which may indicate the irreversible changes.