DUPLICA RealTime HLA-B*5701 EZ Type Kit
Human leukocyte antigen (HLA) genes are localized to chromosome 6. These genes affect the response of the immune system to infection by viruses and bacteria, and direct antibody production against foreign substances or antigens. HLA-B is a subclass of the HLA system.
Based on DNA sequence variation, over 2,400 different versions of the gene, that codes for the HLA-B antigen, have been identified in the human population. The HLAB* 57 family consists of at least 57 closely related genes. Around 5% to 8% of the Western European and Hispanic populations express 57-like antigens, so this represents a common HLA genotype. This genotype is less frequent in other ethnic groups, and is found in <2% of people of African origin.
Abacavir (ABC) is a nucleoside reverse-transcriptase inhibitor antiretroviral indicated in combination with other antiretroviral agents for the treatment of HIV-1 infection, in adult and paediatric patients. Abacavir is associated with potentially serious hypersensitivity reactions in 3–9% of Caucasian patients that require immediate and permanent discontinuation of the drug.
It has been shown that carriers of the allele 57:01 of the HLA locus B (HLA-B*57:01) are at high risk for developing Abacavir Hypersensitivity Reaction (ABC-HSR) and that prospective genetic screening for HLA-B*57:01 greatly diminishes or abolishes the occurrence of ABC-HSR. In July 2008, the US FDA approved a label change for Abacavir to include a boxed warning indicating that patients who carry the HLA-B*57:01 allele are at high risk for experiencing a hypersensitivity reaction to Abacavir and a recommendation to screen for HLA-B*57:01 prior to the initiation of Abacavir therapy.