HLA-B*57:01 Genotyping (for Abacavir Hypersensitivity) Test
About HLA-B*57:01 Genotyping (for Abacavir Hypersensitivity) Test
| Field | Value |
|---|---|
| Also Known As | HLA-B5701 test, HLA-B*5701 typing, Abacavir hypersensitivity genotyping, HLA-B57, HLAB5701 |
| Sample Type | Peripheral whole blood (collected in an EDTA tube, a special anticoagulant tube) |
| Fasting Required | No fasting required |
| Report Time | 20 days |
| Recommended For | All individuals of any age or gender being considered for abacavir-based HIV treatment |
| Price | Starting at ₹4,800 |
What is an HLA-B*57:01 Genotyping (for Abacavir Hypersensitivity) Test?
The HLA-B*57:01 Genotyping test is a genetic blood test that checks whether a person carries a specific gene variant linked to severe allergic reactions to abacavir, an antiretroviral drug used in HIV treatment. A small blood sample is drawn from a vein and analysed in a molecular diagnostics laboratory using a technique called Sanger sequencing. The result is simply positive or negative. Doctors commonly order this test before prescribing any abacavir-containing regimen.
What Does an HLA-B*57:01 Genotyping (for Abacavir Hypersensitivity) Test Measure?
This is a qualitative pharmacogenomic test, meaning it predicts how your body may respond to a specific medicine based on your genetic makeup. It detects one specific genetic variant:
| Parameter | What It Tells You |
|---|---|
| HLA-B*57:01 allele (a particular version of the HLA-B gene) | Whether you carry at least one copy of this allele, which significantly raises the risk of a severe allergic reaction to abacavir |
The result is either positive (allele detected) or negative (allele not detected). There are no in-between results because HLA genes follow a codominant pattern of expression.
Why is an HLA-B*57:01 Genotyping (for Abacavir Hypersensitivity) Test Done?
Doctors order the HLA-B*57:01 Genotyping test in specific clinical situations before prescribing certain medicines. Here is a closer look at when and why it is needed.
Common Symptoms That May Require This Test
This test is not ordered based on symptoms. It is ordered before starting a medicine to prevent a reaction. The following situations typically prompt a doctor to request it:
- Planning to start abacavir therapy for the first time
- Switching to an abacavir-containing HIV treatment regimen
- Restarting abacavir when prior HLA-B*57:01 status is unknown
- Being considered for pazopanib, a cancer treatment drug
- Having a known or suspected HIV diagnosis requiring antiretroviral therapy
Conditions This Test Can Help Detect
This test identifies genetic risk rather than an existing illness. The following risks are assessed:
- High risk of abacavir hypersensitivity reaction (fever, rash, nausea, and breathing difficulties affecting 5 to 8% of abacavir users)
- Increased risk of raised liver enzyme levels when taking pazopanib
- Elevated risk of flucloxacillin-induced liver injury
The HLA-B*57:01 allele is notably common in Indian populations, with a reported frequency of up to 11%. This makes pre-treatment screening especially relevant for HIV patients in India.
How to Prepare and What to Expect
No special preparation is needed for this test. Read on for the key details about the HLA-B*57:01 Genotyping test procedure.
Do You Need to Fast?
No. Fasting is not required before this test. You may eat and drink normally before your appointment. If additional tests are ordered alongside this one, check with your doctor whether any of those require fasting.
Practical Tips Before Your Test
Keep the following points in mind before your sample is collected:
- Bring a detailed clinical history, including your symptoms, previous test results, and family history, as this is required for the test.
- Inform your doctor if you have ever received a bone marrow (haematopoietic stem cell) transplant or a liver transplant from a donor, as this can interfere with the test result.
- Carry your HIV treatment history and any records of prior drug allergies or reactions.
- Continue all current medications unless your doctor has advised you to stop.
Step-by-Step Procedure
Here is what happens during a typical blood collection for this test:
- A trained phlebotomist cleans the area on your arm with an antiseptic swab.
- A small amount of blood (approximately 2 mL) is drawn from a vein in your arm using a fine needle.
- The blood is collected into a lavender-topped EDTA tube, which preserves the sample for DNA analysis.
- The tube is labelled with your details and stored at 2 to 8 degrees Celsius for safe transport.
- The sample is dispatched to a specialised molecular diagnostics laboratory.
- At the laboratory, Sanger sequencing is used to detect whether the HLA-B*57:01 allele is present.
Factors That Can Affect Accuracy
Certain factors can affect how reliable your result is:
- A prior allogeneic (donor) bone marrow or liver transplant, as donor DNA may produce a result reflecting the donor's genotype
- Recent blood transfusion, which can introduce donor DNA into the sample
- An inadequate or degraded blood sample due to improper storage or handling
- Centrifugation of the specimen, which should be avoided
Understanding Your HLA-B*57:01 Genotyping (for Abacavir Hypersensitivity) Test Results
Your result will be either positive or negative. Unlike most blood tests, there are no numerical values or ranges for this test. Your doctor will use the result, along with your full medical history, to guide treatment decisions.
| Result | Meaning |
|---|---|
| Negative (HLA-B*57:01 not detected) | Low risk of abacavir hypersensitivity; abacavir may be considered for your treatment |
| Positive (HLA-B*57:01 detected) | High risk of abacavir hypersensitivity; abacavir must not be prescribed |
Disclaimer: These ranges are general guidelines. Your doctor will interpret your results based on your age, health history, and other factors. Always consult a qualified healthcare professional for personalised medical advice.
Results During Special Conditions
Some medical situations can affect how results should be interpreted:
- Allogenic transplant recipients: If you have received a bone marrow or liver transplant from a donor, the result may reflect the donor's genetic profile rather than your own. Always disclose this history before the test.
- Recent blood transfusion: Donor white blood cells in transfused blood can theoretically introduce foreign DNA, which may affect the test result.
How to Maintain Healthy Levels
As this test measures a fixed genetic trait, no lifestyle changes can alter your HLA-B*57:01 status. The following steps are helpful regardless of your result:
- If you test positive, always inform any new healthcare provider about your HLA-B*57:01 status before starting new medicines.
- Keep a copy of your test result in your medical records, as the result is valid for life and you will not need to repeat the test.
- Discuss all medication options openly with your doctor so that a safe alternative to abacavir can be chosen if needed.
Lupin Diagnostics HLA-B*57:01 Genotyping (for Abacavir Hypersensitivity) Test Price and Home Collection
The HLA-B*57:01 Genotyping test cost at Lupin Diagnostics starts at ₹4,800, and home collection is available. A trained phlebotomist will visit your home to collect the blood sample at a time that suits you.
| City | Approximate Price (₹) |
|---|---|
| BHOPAL | 4800 |
| CHENNAI | 4800 |
| HYDERABAD | 4800 |
| KOLKATA | 4800 |
| NAVI MUMBAI | 4800 |
| PUNE | 4800 |
Disclaimer: Prices are indicative and may vary by location. Please confirm the current price at the time of booking.
How to Book
Follow these steps to book your HLA-B*57:01 Genotyping test online:
- Select the test on the Lupin Diagnostics website.
- Choose your city and preferred time slot.
- Opt for home sample collection by a certified phlebotomist, or visit your nearest Lupin Diagnostics centre.
- Receive your report via email or WhatsApp within the stipulated turnaround time.
Home Collection
HLA-B*57:01 Genotyping test home collection is available across cities. Your blood sample is collected at home by a certified phlebotomist and processed in a NABL-accredited laboratory. Your digital report is delivered to you via email or WhatsApp once ready.
Frequently Asked Questions
The HLA-B*57:01 Genotyping test checks whether you carry a gene variant linked to a severe allergic reaction to abacavir, a medicine used in HIV treatment. Doctors order it before prescribing abacavir to avoid a potentially serious drug reaction. The result is either positive or negative.
Anyone being considered for abacavir-based HIV treatment should have this test done first. It is also relevant if your doctor is considering prescribing pazopanib, a cancer treatment drug. The FDA recommends screening all patients before starting abacavir therapy.
No fasting is needed. You may eat and drink as usual before the test. The most important thing is to inform your doctor if you have ever received a bone marrow or liver transplant from a donor, as this can affect your result. Bring your clinical history and any prior drug-allergy records.
Only once in your lifetime. Your genetic makeup does not change, so the result remains valid permanently. However, if you are restarting abacavir and your previous HLA-B*57:01 status is not on record, your doctor may ask you to test again.
A positive result means you carry at least one copy of the HLA-B*57:01 allele. This places you at high risk of a severe hypersensitivity reaction to abacavir. Your doctor will prescribe a different antiretroviral medication that is safe for you to use.
Yes. The HLA-B*57:01 allele is more common in Indian populations than in many other groups globally, with a frequency of up to 11%. This means a higher proportion of HIV patients in India may carry this allele, making pre-treatment HLA-B*57:01 Genotyping screening particularly valuable before starting abacavir.
HLA-B*57:01 Genotyping (for Abacavir Hypersensitivity) Test
