[HIV tests].

In the care and treatment of HIV-infected patients, several laboratory methods are indispensable. The diagnosis of HIV infection is established by one of the following methods: detecting antibodies to the virus; detecting the viral p24 antigen; detecting viral nucleic acid; or culturing HIV. The most widely used test is the detection of antibodies to HIV. Rapid serological tests take only 15 minutes for all procedures and are very useful in clinical settings. The rapid saliva test has also been developed, but is not available in Japan. Recently, some serological test kits have become commercially available via websites. Thus, people can perform tests by themselves without visiting testing facilities, with samples being sent by post. The CD4 T-cell count is the most important marker to determine when to start anti-HIV drugs. In addition, resistance testing should be used to guide the selection of the antiretroviral regimen in both treatment-naïve and -experienced patients. The following tests are still experimental but very important: HLA-B5701 testing should be performed prior to the initiation of abacavir. Recent studies have revealed that HLA-B5701 is strongly associated with the abacavir hypersensitivity reaction. However, fortunately, Japanese rarely have HLA-B*5701. The viral tropism assay should be performed prior to the initiation of the CCR5 antagonist.