| [ Summary ] |
The human immunodeficiency virus (HIV) infects CD4-positive lymphocytes (CD4), which are immunocompetent cells. After HIV infection, the CD4 cell count gradually decreases. The patients enter carrier stage that lasts from several years to about 10 years. When the CD4 cell count drops below a certain level, various opportunistic diseases can occur because of defective cellular immunity, and the acquired immunodeficiency syndrome (AIDS) appears. The CD4 cell count and plasma HIV-RNA level are important parameters for assessing the clinical course of HIV infection and for deciding the treatment. In recent year, potent anti-HIV therapy has been introduced to suppress HIV proliferation and reduce the viral loads or to increase the CD4 cell count and prevent opportunistic infections, and the prognosis of HIV infection has improved markedly because of progress in the prevention and treatment of opportunistic infections. It is necessary to disseminate the latest accurate knowledge concerning HIV infection and educate the public about the prevention of this infection. |