One of the most effective current methods of direct HIV detection is specific amplification of nucleic acids in vitro by polymerase chain reaction (PCR). This method has a lot of advantages:
- detection of virus DNA/RNA allows reducing the length of the serological window;
- PCR is an indispensable approach for HIV-diagnostics in children born from HIV-infected mothers:
- determination of HIV RNA in the blood plasma (viral load) is an obligatory procedure to monitoring of the therapy effectiveness

HIV-infection diagnostics in children born from HIV-infected mothers is difficult due to the fact that mother antibodies to HIV persist in such children blood for a long time. But not every child born from the infected mother is infected with HIV, in spite of the fact that children are subjected to high risk of HIV infection in the intrauterine period, during the delivery and breast feeding. If no preventive measures are taken, the risk of mother-to-child HIV transmission in children makes 20-45 percent. Today effective measures intended at prevention of vertical HIV transmission can reduce risk to 1-2 percent.
The problem of earlier HIV-infection diagnostics in newborns was solved several years ago with development of molecular-genetic methods that allow detection of HIV genome fragments in the peripheral blood at early infection stages. The evidence was obtained that the HIV provirus DNA is determined by the age of one month in the majority of children and practically in all - by the age of 6 months. Based on these data it is recommended to conduct the polymerase chain reaction (PCR) for HIV provirus DNA for the first time within 48 hours after birth and on the 6-8th week of the child life irrespective of the result of the first examination. The final decision about HIV-infection presence in child is made not later than the age of 6 months of the child.

Abacavir is a nucleoside reverse-transcriptase inhibitor with activity against the human immunodeficiency virus (HIV), available for once-daily use in combination with other antiretroviral agents, that has shown efficacy, few drug interactions, and a favorable long-term toxicity profile. The most important adverse effect of abacavir that limits its use in therapy and mandates a high degree of clinical vigilance is an immunologically mediated hypersensitivity reaction affecting 5 to 8% of patients during the first 6 weeks of treatment. In 2002, an association between a diagnosis of hypersensitivity reaction to abacavir and carriage of the major histocompatibility complex class I allelee HLA-B*5701 was reported independently by several independent studies.
Studies of cohorts with HIV infection have also shown that avoiding abacavir in HLA-B*5701 positive patients significantly reduced the incidence of suspected hypersensitivity reaction up to 0,5%. Many clinical studies recommend for this reason, the pharmacogenetic molecular testing of the carriage of the major histocompatibility complex class I allelee HLA-B*5701 in all HIV positive patients treated with abacovir.
HLA-B*5701 Real-TM test can predict who will develop a severe allergic reaction to the anti-HIV drug abacavir as the presence of HLA-B*5701 is significantly associated with an abacavir hypersensitivity.