Pharmacogenomics

HLA-B*57:01

A human leukocyte antigen allele strongly associated with a severe, immune-mediated hypersensitivity reaction to the antiretroviral drug abacavir.

In depth

Carriers present abacavir-derived peptides on this HLA class I molecule in a way that triggers a T-cell-mediated hypersensitivity reaction, typically within the first six weeks of therapy, with fever, rash, and gastrointestinal or respiratory symptoms that can progress to a life-threatening reaction on re-exposure. The negative predictive value of a negative test is very high, meaning a carefully phenotyped negative result effectively rules out this specific reaction.

CPIC and product labelling recommend screening for HLA-B*57:01 before starting abacavir and avoiding the drug entirely in carriers, regardless of the planned dose.

Clinical pearl

HLA-B*57:01 testing before abacavir is standard of care; a positive result is a permanent contraindication to abacavir, not a dose-adjustment issue.

Example drugs

Abacavir
TRIn Turkish

HLA-B*57:01

Antiretroviral ilaç abakavire karşı ciddi, immün aracılı bir aşırı duyarlılık reaksiyonuyla güçlü şekilde ilişkili bir insan lökosit antijeni (HLA) alelidir.

Taşıyıcılar, abakavirden türeyen peptidleri bu HLA sınıf I molekülü üzerinde, tedavinin genellikle ilk altı haftası içinde T hücre aracılı bir aşırı duyarlılık reaksiyonunu tetikleyecek şekilde sunar; ateş, döküntü ve yeniden maruziyette hayatı tehdit eden bir reaksiyona ilerleyebilen gastrointestinal veya solunumsal belirtiler görülür. Negatif bir testin negatif prediktif değeri çok yüksektir; yani dikkatle fenotiplendirilmiş negatif bir sonuç bu spesifik reaksiyonu büyük ölçüde dışlar.

CPIC ve ürün etiketlemesi, abakavire başlamadan önce HLA-B*57:01 taraması yapılmasını ve planlanan dozdan bağımsız olarak taşıyıcılarda ilaçtan tamamen kaçınılmasını önerir.

Abakavir öncesi HLA-B*57:01 taraması standart uygulamadır; pozitif sonuç bir doz ayarlama meselesi değil, abakavir için kalıcı bir kontrendikasyondur.

Updated 24.09.2026 0 views Educational reference — verify against current sources before clinical use.

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