MICROGLIOSISINWHITEMATTER OF THE BRAIN IN CHRONIC HCV-INFECTION: MORPHOLOGICAL STUDY

Abstract

The course of a chronic HCV infection in 50% of cases is followed by affection of the brain. Its most frequent manifestations are various cognitive and psychogenic and neurological disorders. It is considered they are based on the activation of HCV infected microglial cells and related to this exitotoxic injury of neurons. According to the data of literature similar changes of microglia in white matter play an important role in a pathogenesis of HIV-associated subcortical dementia. Despite active studying the role of microglia in HCV infection, structural changes and tissue reactions of these cells in nervous tissue remain unexplored. In this regard the purpose of this research was comprehensive immunomorphological research of microglia cells in white matter of different departments of brain in HCV infection. Object of a research was autopsy samples of white brain matter from 40 patients died in the outcome of a chronic HCV infection. 20 people deceased without infectious and mental pathology made up the control group. After histological processing by standard methodic microscopic sections of white matter samples were prepared and stained with review and elective stainings. The immunohistochemical research was conducted using antibodies to virus protein NS3 and antibodies to CD68 microglia cells. The evaluation of microglia cells reactive changes in nervous tissue was performed with submitted earlier methodic. Statistical processing of results was carried out by dispersive Kruskal-Wallis analysis using the SSPS application programs. Level of significance p was accepted equal 0,05. It was established that during chronic HCV infection in white matter of the brain occurs productive changes of microglia cells. They are presented with diffuse and focal anizomorphic microgliosis which expressiveness differs depending on departments of the brain develop (p=0,000). The highest rates of a microgliosis are defined in white matter of brain hemispheres and a brainstem (р=0,05). Morphological features of microgliosis during HCV infection include glial knots formation, phagocytic transformation of microglia with prevalence of amoeboid cells, granular globes appearance, rod microglia congestions in a hippocampus and also degenerative changes in perifocal white matter. These changes of a microglia can be considered as a morphological equivalent of infected with HCV microglia cells activation. The revealed changes indicate that the microgliosis is typical morphological feature of brain injury during chronic HCV infection, and it plays an important role in the pathogenesis of the HCV-associated damage of central nervous system.