The study of Associations between TNFα GENE G308A polymorphism and clinical-neurological, neuroimaging, hemodynamic characteristics and cognitive dysfunction in patients with post-infectious encephalopathy
Authors: Duve Khrystyna 
Published: December 2023

Introduction. Infectious diseases can affect brain function and cause the development of encephalopathy, even if the pathogen does not directly affect the central nervous system. Infections caused by viruses, bacteria, or parasites can lead to a secondary inflammatory response in the brain, commonly known as neuroinflammation, through the action of inflammatory mediators that affect the brain endothelium and parenchyma, and the response of brain cells to these mediators. Neurological consequences associated with infectious diseases are poorly understood. Nowadays, there is no established strategy for the treatment or prevention of neurological damage associated with peripheral infections.

Aim of study was: to establish probable associations of the G308A polymorphic variant of the TNFα gene with clinical-neurological, neuroimaging, hemodynamic characteristics and cognitive dysfunction in patients with post-infectious encephalopathy.

Material and methods. 128 patients with PIE who were undergoing treatment in the neurological departments of the communal non-profit enterprise "Ternopil Regional Clinical Psychoneurological Hospital" during 2021-2022 were examined. 26 patients underwent molecular genetic analysis. The control group consisted of 12 practically healthy persons, representative in terms of age and sex. All patients met the inclusion criteria for the study. Neuroimaging was performed using multispiral computed tomography (CT) or magnetic resonance imaging (MRI). The state of cerebral blood flow was studied using transcranial duplex scanning (TCI) of intracranial vessels and extracranial brachiocephalic vessels on a Philips HDI device. Research in the cognitive sphere was carried out using the Montreal Cognitive Test (The Montreal Cognitive Assessment, MoCA). The molecular genetic study of the G308A polymorphic variant of the TNFα gene was carried out according to standard protocols developed in the molecular genetic laboratory of the state institution "Reference Center for Molecular Diagnostics of the Ministry of Health of Ukraine".

The results. Analyzing the dependence of clinical-neurological syndromes, neuroimaging, hemodynamic characteristics, and cognitive dysfunction on the polymorphic variant G308A of the TNFα gene in patients with PIE, probable differences in the distribution of genotype frequencies were established only for clinical-neurological syndromes (cephalic syndrome, p=0.005 and movement disorder syndrome, p =0.038) and neuroimaging changes (gliosis phenomenon, p=0.026). Regarding the frequency distribution of alleles of the G308A polymorphic variant of the TNFα gene in patients with PIE, a probable predominance of carriers of the A allele among persons with cephalic syndrome compared to persons without cephalic syndrome was found (91.67% vs. 8.33%).

Conclusions. Thus, the allelic polymorphism of the TNFα gene affects the course of PIE, which determines the expediency of further research.