Sorted By Test Name - Mayo Medical Laboratories

HL57O
60347
which generally occur during the first 6 weeks of treatment, are often nonspecific and include skin rashes,
gastrointestinal symptoms (eg, nausea, vomiting, diarrhea, and abdominal pain), and respiratory
symptoms. Fatalities have been reported with abacavir. Prospectively testing for the HLA-B*5701
genotype and excluding HLA-B*5701-positive individuals from treatment with abacavir decreases the
incidence of abacavir hypersensitivity. The HLA-B*5701 allele is also associated with
flucloxacillin-induced liver injury in a single study. Individuals who have at least one copy of the
HLA-B*5701 allele have an 80-fold increased risk of serious liver injury when treated with flucloxacillin.
The actual liver injury is thought to be caused by a polymorphism in the neighboring HCP5 gene that is
located in the major histocompatibility gene cluster and is inherited tightly linked to the HLA-B*5701
allele. See Abacavir Hypersensitivity Testing and Initial Patient Management Algorithm in Special
Instructions.
Useful For: Predicting likelihood of hypersensitivity reactions to abacavir in HIV-infected patients,
based on the presence of the human leukocyte antigen (HLA)-B*5701 allele Aiding in differentiating
between true hypersensitivity to abacavir versus other underlying causes (eg, concomitant infection,
reaction to other drugs, or inflammatory disease)
Interpretation: Positivity for human leukocyte antigen (HLA)-B*5701 confers high risk for
hypersensitivity to abacavir. See Abacavir Hypersensitivity Testing and Initial Patient Management
Algorithm in Special Instructions.
Reference Values:
An interpretive report will be provided.
Clinical References: 1. Mallal S, Nolan D, C Witt, et al: Association between presence of
HLA-B*5701, HLA-DR7, and HLA-DQ3 and hypersensitivity to HIV-1 reverse-transcriptase inhibitor
abacavir. Lancet 2002;359:727-732 2. Faruki H, Heine U, Brown T, et al: HLA-B*5701 clinical testing:
early experience in the United States. Pharmacogenet Genom 2007;17:857-860 3. Sun HY, Hung CC, Lin
PH, et al: Incidence of abacavir hypersensitivity and its relationship with HLA-B*5701 in HIV-infected
patients in Taiwan. J. Antimicrob Chemother 2007;60:599-604 4. Mallal S, Phillips E, Carosi G, et al:
HLA-B*5701 screening for hypersensitivity to abacavir. N.Engl J Med 2008;358:568-579 5. Saag M,
Balu R, Brachman P, et al: High sensitivity of HLA-B*5701 in whites and blacks in
immunologically-confirmed cases of abacavir hypersensitivity. 4th IAS Conference on HIV Pathogenesis,
Treatment, and Prevention. July 22-25, 2007. Sydney. Abstract WEAB305) 6. Daly AK, Donaldson PT,
Bhatnagar P, et al: HLA-B*5701 genotype is a major determinant of drug-induced liver injury due to
flucloxacillin. Nat Genet 2009;41:816-9
HLA-B 5701 Genotype, Abacavir Hypersensitivity, Saliva
Clinical Information: 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 650 different versions of the gene that codes for the HLA-B antigen have
been identified in the human population. The HLA-B*57 family consists of at least 16 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