The human immunodeficiency virus, upon entering the bloodstream, invades macrophages, microglia and lymphocytes, which are important in the formation of the body’s immune responses. The virus destroys the ability of immune cells to recognize their antigens as foreign, inhabits the cell and begins reproduction. After the multiplied virus is released into the bloodstream, the host cell dies and the viruses infiltrate healthy macrophages. The syndrome develops slowly (years), in a wave-like manner.
At first, the body compensates for the mass death of immune cells by producing new ones; over time, the compensation becomes insufficient, the number of lymphocytes and macrophages in the blood significantly decreases, the immune system is destroyed, the body becomes defenseless against both exogenous infection and bacteria inhabiting organs and tissues normally (leading to the development of opportunistic infections). In addition, the defense mechanism against reproduction of defective blastocytes – malignant cells – is violated.
Invasion of immune cells by the virus often provokes various autoimmune conditions, in particular characterized by neurological disorders as a result of autoimmune damage to neurocytes, which may develop even earlier than the clinic of immunodeficiency.
Classification
There are 5 stages in the clinical course of HIV infection: incubation, primary manifestations, latent, secondary disease and terminal. The stage of primary manifestations can be asymptomatic, in the form of primary HIV infection, as well as combined with secondary diseases. The fourth stage, depending on the severity, is subdivided into periods: 4A, 4B, 4B. The periods undergo phases of progression and remission, which differ depending on the available antiretroviral therapy or its absence.