Host defense abnormalities as causes of increased susceptibility to infections in children with HIV infection.
Infection with human immunodeficiency virus (HIV) is followed by an increased susceptibility to a series of opportunistic and common pathogenic organisms that can be viruses, bacteria, fungi or protozoa. This increased susceptibility has been associated with multiple defects underlying the whole spectrum of host defenses. Numerical and functional deficiencies in CD4+ T lymphocytes are the hallmark of progression of the disease. In addition, B cells become affected as evidenced by a spontaneous hyperproduction of immunoglobulins which are, however, dysfunctional, and an impaired production of specific antibodies in response to a variety of antigens. Natural killer cell cytotoxicity is also defective. Both monocytes/macrophages and neutrophils are affected by HIV and exhibit defective chemotactic and bactericidal function as well as defective antibody dependent cellular cytotoxicity and certain antifungal activities. These defects may explain the heightened frequency of infections in this population of patients, especially in children. Restoration of them with specific immunotherapeutic agents may decrease the incidence of infections.
Roilides
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D001402:B-Lymphocytes / Q000276:immunology; D002648:Child; D015658:HIV Infections / Q000276:immunology*; D006801:Humans; D007107:Immune System / Q000503:physiopathology*; D009504:Neutrophils / Q000502:physiology; D013601:T-Lymphocytes / Q000276:immunology