Selenoprotein deficiency, Immunity and HIV Infection

Selenoprotein deficiency, Immunity and HIV Infection

Immunologic Mechanisms

Immunodeficiency syndrome is a table which shows a deficit of humeral immunity, cellular or both, and is characterized by an increased susceptibility to infections, and in some cases diseases autoimmune diseases, and even one of them, isolated deficiency of IgA, reaching an incidence of about 1 for every 600 individuals. The defect in humeral immunity often causes chronic or recurrent infections of the lungs, meningitis and bacteremia, usually by bacteria phylogenic (H. influenza, S. pneumonia, etc.). The deficiency in cellular immunity predisposes to disseminated viral infections (mainly viruses as latent herpes simplex or cytomegalovirus), candidacies and other systemic fungal infections, especially to pneumonia caused by Pneumocystis carinii. Finally, patients with both humeral and cellular deficits are exposed to all infections, even by those agencies that are not considered pathogens (Carael, 2002). The treatment of these syndromes is extremely difficult, in constant evolution and long-running argument.

Healthy individuals are protected against microorganisms through different mechanisms. Some of these protective mechanisms include innate immunity (also called natural or native). The characteristics of innate immunity is limited to the ability to discriminate an organism from another and their nature moderately stereotypical, and its role very similar against most infectious agents (Carael, 2002). The essential elements of innate immunity are: 1) physical and chemical barred as epithelia and antimicrobial substances produced in the epithelial surface, 2) protein blood, among which include members of the system of complement and other mediators of inflammation , and 3) cells phagocytic (neutrophils, macrophages) and other leukocytes such as NK cells. Innate immunity represents the first line of defense against microorganisms. The pathogenicity of microorganisms is related in part to its ability to resist innate immunity mechanisms.

Unlike innate immunity defense mechanisms are much more evolved that are stimulated after exposure to infectious agents, and whose intensity and defensive capabilities further increase after exposure to a particular organism. Since this form of immunity develops as a response to infection, it is called adaptive immunity (Carael, 2002). The characteristics of adaptive immunity are exquisite specificity for different molecules; expertise, which enables them to respond uniquely to different types of microbes and their ability to "remember" and respond with more force after repeated exposures to the same microorganism. Because of this ability to discriminate between different organisms, adaptive immunity is also called specific immunity. The components of this are present before exposure to microorganisms, against which are fast responders and stimulated by them (Carael, 2002). The components of specific immunity are the lymphocytes and their products, including antibodies. Foreign substances that induce specific immune responses or are targets of such responses are called ant Igen. Conventionally the immunology is the study of specific immunity and "immune response" means in relation to responses that are specific to different antigens, microbial antigens can be non-infectious substances.

Acquired Immunodeficiency Syndrome (AIDS)

This is an entity caused by the retrovirus HIV, a serious disorder characterized by cellular immunity that favors the emergence of diseases such as Kaposi's ...