Current Features of Secondary (Acquired) Types of Immune Deficiency.

Secondary (acquired) types of immune deficiencies (SID) take a leading place in practice of modern clinical immunology. The causes for SID development are extremely variable. Special attention is concerned with accumulating facts about target action of microorganisms, and first of all viruses, on certain processes in immune system. Damageable action of HIV-1 on cell elements expressing CD4 molecules is known in most precise manner. It is noteworthy that the search of real molecular defects, induced by microorganisms in immune system is required. It is not to be ruled out that the increased level of apoptosis of immune system cells is one of the causes of SID. The basis of it is disbalance between positive and negative activation processes of immunocompetent cells. Multiple factors may serve as apoptogens, including drugs (glucocorticoids etc.), xenobiotics, physical factors (radiation) and many others. In practice of clinical laboratories a certain spectrum of immunological investigations is recommended that allows to diagnose the degree of immunopathology. At present, in clinical practice these methods are focused around flow cytometry (immunophenotyping), immunodiffusion and immunoenzyme tests (determination of immunoglobulins, cytokines, other soluble components of immune system), tests of estimation of immunocompetent cell activation, proliferation and differentiation. As a prospective, some methods, based on identification of molecular defects in cells and soluble factors of immune system, may be taken into consideration.