Cytochrome P450 2C19 Genotyping (CYP2C19) Clopidogrel Resistance Test: Booking, Price, and Results
About Cytochrome P450 2C19 Genotyping (CYP2C19) Clopidogrel Resistance Test: Booking, Price, and Results
| Field | Value |
|---|---|
| Also Known As | CYP2C19 Genotyping, Clopidogrel Genotype Test, Clopidogrel Resistance Test, Plavix Sensitivity Test, Cytochrome P450 2C19 Genotype |
| Sample Type | Peripheral blood (EDTA tube) |
| Fasting Required | No fasting required |
| Report Time | 15 days |
| Recommended For | Adults prescribed clopidogrel therapy, particularly those undergoing stent placement or managing acute coronary syndrome |
| Price | Starting at ₹6,000 |
What is a Cytochrome P450 2C19 Genotyping (CYP2C19) Clopidogrel Resistance Test?
The CYP2C19 test is a genetic test that detects inherited variations in the CYP2C19 gene. This gene codes for an enzyme that converts clopidogrel, a blood-thinning medication, into its active form in the body. A small blood sample collected in an EDTA tube is used for the analysis.
Also known as the Clopidogrel Resistance Test or Plavix Sensitivity Test, it helps doctors understand how a patient's body is likely to respond to clopidogrel. Doctors typically order this test before starting or during clopidogrel therapy.
What Does a Cytochrome P450 2C19 Genotyping (CYP2C19) Clopidogrel Resistance Test Measure?
This test identifies specific variants in the CYP2C19 gene and predicts how well your body can process clopidogrel. Rather than providing a simple numeric result, it classifies you into a metaboliser category based on your inherited gene variants.
The test detects the following alleles (gene variants):
- CYP2C19*1 (Normal allele): The reference variant, associated with normal enzyme activity and effective conversion of clopidogrel to its active form.
- Loss-of-function alleles (*2, *3, *4, *10): Variants that reduce or eliminate enzyme activity, meaning clopidogrel may not work effectively.
- Gain-of-function allele (*17): A variant linked to increased enzyme activity, associated with rapid or ultrarapid processing of clopidogrel.
Results are reported as a diplotype (for example, *1/*2) alongside a predicted metaboliser phenotype, described in the results section below.
Why is a Cytochrome P450 2C19 Genotyping (CYP2C19) Clopidogrel Resistance Test Done?
This test is ordered when a doctor needs to personalise clopidogrel therapy or investigate treatment response. Below are the common reasons it may be requested.
Common Symptoms That May Require This Test
The following clinical situations commonly lead a doctor to order the CYP2C19 test:
- Being prescribed clopidogrel before or after a heart stent procedure
- Recurring cardiovascular events (heart attack or stroke) despite being on clopidogrel
- Suspected clopidogrel resistance or treatment failure
- History of blood clot forming inside a stent (stent thrombosis)
- Adverse reactions to antiplatelet medication
- Pre-procedural evaluation for percutaneous coronary intervention
- A family history suggesting poor response to clopidogrel
Conditions This Test Can Help Detect
A doctor may use this test to guide treatment decisions in several cardiovascular and medication-related contexts:
- Coronary artery disease, particularly in patients undergoing stent placement
- Cerebrovascular disease (stroke or transient ischaemic attack) managed with antiplatelet therapy
- Peripheral arterial disease requiring clopidogrel treatment
- Risk of inadequate antiplatelet effect in patients with loss-of-function gene variants
- Altered metabolism of other CYP2C19-processed medications, including certain antidepressants and antifungal drugs
How to Prepare and What to Expect
No special preparation is needed for this test. The procedure is straightforward and similar to a routine blood draw.
Do You Need to Fast?
No, fasting is not required. You can eat and drink normally before your sample is collected. There are no dietary or fluid restrictions specific to this test.
Practical Tips Before Your Test
A few simple steps will help ensure a smooth collection:
- Bring a detailed clinical history, including your symptoms, current medications, previous test results, and relevant medical records, as this is required for the test.
- Carry a complete list of all prescription and over-the-counter medicines you are taking, since some may be processed by the CYP2C19 enzyme.
- Drink water as normal before the test; staying hydrated makes the blood draw easier.
- Wear clothing with a loose sleeve for easy access to the arm vein.
- Inform the phlebotomist if you have recently received a blood transfusion or undergone a stem cell or liver transplant, as these may affect results.
Step-by-Step Procedure
- A trained phlebotomist cleans the skin on the inside of your elbow with an antiseptic swab.
- A small needle is inserted into a vein to draw approximately 2 mL of blood.
- The blood is collected directly into a lavender-top EDTA tube to preserve the DNA.
- The tube is gently inverted several times to mix the sample; it is not shaken or centrifuged.
- The needle is removed, and a small bandage or cotton pad is placed on the site.
- The sample is stored at 2 to 8 degrees Celsius and dispatched to the laboratory for DNA extraction and Sanger sequencing analysis.
Factors That Can Affect Accuracy
Certain situations may influence the reliability of your CYP2C19 test result:
- Recent non-leukocyte reduced blood transfusion (donor DNA may be present in the sample for up to six weeks)
- Allogeneic haematopoietic stem cell transplantation (a pre-transplant specimen is recommended for accurate genotyping)
- Liver transplantation (results may not accurately reflect your own CYP2C19 status)
- This test does not detect rare or novel CYP2C19 variants beyond the specific alleles included in the panel
- Other factors such as age, body weight, kidney disease, diabetes, and certain proton pump inhibitors can also influence how clopidogrel works in the body, independent of the genotype result
Understanding Your Cytochrome P450 2C19 Genotyping (CYP2C19) Clopidogrel Resistance Test Results
Results are reported as a metaboliser phenotype based on which gene variants you carry. Unlike routine blood tests, there is no single "normal" number. Your doctor will explain what your phenotype means for your treatment. The table below describes each category:
| Phenotype | Enzyme Function | Example Diplotype |
|---|---|---|
| Ultrarapid Metaboliser (UM) | Higher than normal enzyme activity | *17/*17 |
| Rapid Metaboliser (RM) | Slightly increased enzyme activity | *1/*17 |
| Normal Metaboliser (NM) | Normal enzyme activity | *1/*1 |
| Intermediate Metaboliser (IM) | Reduced enzyme activity | *1/*2, *1/*3 |
| Poor Metaboliser (PM) | Minimal or no enzyme activity | *2/*2, *2/*3, *3/*3 |
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
Certain medical histories can affect how results are interpreted:
- Blood transfusion: If you have received a non-leukocyte reduced blood transfusion, the sample may contain donor DNA. The result may not accurately reflect your own genotype until approximately six weeks after the transfusion.
- Stem cell transplantation: After an allogeneic haematopoietic stem cell transplant, a sample taken before the transplant is recommended to obtain an accurate result.
- Liver transplantation: The CYP2C19 genotype result may not accurately reflect how your body processes CYP2C19-metabolised drugs after a liver transplant.
- Drug interactions: The CYP2C19 enzyme processes multiple medications. If you are taking clopidogrel alongside other drugs metabolised by this enzyme, the overall effect on drug processing may differ from what the genotype result alone suggests.
How to Maintain Healthy Levels
Because this is a genetic test, the result itself does not change. The following general steps support good cardiovascular health:
- Follow your prescribed antiplatelet or cardiovascular medication plan exactly as directed by your doctor.
- Attend all scheduled follow-up appointments with your cardiologist to review how your treatment is working.
- Maintain a heart-healthy lifestyle with a balanced diet, regular physical activity, and avoidance of smoking.
Lupin Diagnostics Cytochrome P450 2C19 Genotyping (CYP2C19) Clopidogrel Resistance Test Price and Home Collection
The CYP2C19 test cost at Lupin Diagnostics starts at ₹6,000, and home sample collection is available across cities. The city-wise pricing is listed below:
| City | Approximate Price (₹) |
|---|---|
| BHOPAL | 6000 |
| CHENNAI | 6000 |
| HYDERABAD | 6000 |
| KOLKATA | 6000 |
| NAVI MUMBAI | 6000 |
| PUNE | 6000 |
Disclaimer: Prices are indicative and may vary by location. Please confirm the current price at the time of booking.
How to Book
- 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
CYP2C19 test home collection is available across multiple cities through Lupin Diagnostics. A trained phlebotomist visits your location at your chosen time to collect the blood sample. All samples are processed in NABL-accredited laboratories, and your report is delivered digitally for convenient access.
Frequently Asked Questions
The CYP2C19 test is a pharmacogenomic test that checks for inherited variations in the CYP2C19 gene. These variations affect how well the body converts clopidogrel into its active form. Doctors use the result to choose the most appropriate antiplatelet medication and dose for each patient.
This test is typically recommended for adults who are about to start clopidogrel therapy or who are already taking it without the expected benefit. It is also ordered before procedures such as coronary stent placement, or when a patient has experienced recurring cardiovascular events despite being on clopidogrel.
No, fasting is not required. You can eat and drink as normal before the test. No dietary or lifestyle changes are needed in preparation.
The report is delivered within 15 days of sample collection at Lupin Diagnostics. The analysis uses Sanger sequencing, a method that accurately identifies specific gene variants in the CYP2C19 gene.
No. Because your genes do not change over time, the CYP2C19 test is generally a one-time test. The result is valid for life. The only exception is if you have undergone a stem cell transplant, in which case your doctor may advise retesting with a pre-transplant sample.
The CYP2C19 test procedure involves a standard blood draw, which carries minimal risk. You may feel a brief pinch at the needle site or notice slight bruising afterwards. Serious complications are rare and similar to those of any routine blood collection.
Cytochrome P450 2C19 Genotyping (CYP2C19) Clopidogrel Resistance Test: Booking, Price, and Results
