The human immunodeficiency retrovirus causes acquired immunodeficiency syndrome (AIDS), in which immunity is profoundly reduced through destruction of CD4 T lymphocytes and macrophages. The CD4 recognize infected cells and foreign antibodies, activate antibody-producing lymphocytes, and orchestrate cell-mediated immunity in which infected cells and foreign antigens are destroyed. When viral loads climb and CD4 counts drop, the immune system cannot resist the development of opportunistic infections and malignancies. AIDS is defined as a CD4 count < 200/ul or occurrence of AIDS defining conditions. AIDS is a syndrome once considered rapidly fatal. However, HIV has become a chronic disease as antiretroviral drugs and drugs controlling opportunistic infections have successfully prolonged life: over 35.3 million people across the globe are living with HIV, of whom 1.3 million are North Americans. Overall, the impact of antiretroviral on survival has made it difficult to use traditional prognostic indicators, and the clinical course of HIV/AIDS is fluctuating, with considerable variation among patients, and is marked by a number of opportunistic infections requiring treatment. Effective prevention strategies, earlier diagnosis, and the use of antiretroviral therapy (ART) have all improved survival rates. Despite this, there remain approximately 20,000 AIDS deaths per year in the United States. A viral load of more than 100,000 copies of a CD4 count below 25 cells/mcl may predict a terminal condition if a patient is declining in function, choosing to forgo medication, antiretrovirals are no longer effective, or life-threatening complications have developed. Continue reading “Acquired Immunodeficiency Syndrome (AIDS) 艾滋病 (Reading & Sharing)” →