Chimerism by STR (Pretransplant) Test: Booking, Price, and Results
About Chimerism by STR (Pretransplant) Test: Booking, Price, and Results
| Field | Value |
|---|---|
| Also Known As | STR Chimerism Testing, Pretransplant Chimerism Analysis, Engraftment Baseline Testing, Recipient Germline Genotyping |
| Sample Type | Peripheral blood (whole blood) in an EDTA tube |
| Fasting Required | No fasting required |
| Report Time | 15 days |
| Recommended For | All ages, male and female; patients scheduled for allogeneic bone marrow or stem cell transplantation |
| Price | Starting at ₹9,000 |
What Is a Chimerism by STR (Pretransplant) Test?
The Chimerism by STR test is a specialised DNA-based test performed before an allogeneic bone marrow or stem cell transplant. It maps the recipient's unique genetic profile using short tandem repeat (STR) markers, which are specific, stable DNA sequences that vary between individuals. This pretransplant baseline profile is essential for monitoring donor cell engraftment after the transplant. The test is also called STR Chimerism Testing or Recipient Germline Genotyping.
What Does a Chimerism by STR (Pretransplant) Test Measure?
This test analyses specific regions of the recipient's DNA to create a genetic fingerprint that will be compared against post-transplant samples. The key elements measured are listed below:
| Component | What It Tells Us |
|---|---|
| Short Tandem Repeat (STR) Markers | Stable, repeating DNA sequences that uniquely identify an individual |
| STR Panel (15 to 20 markers) | Includes markers such as D8S1179, D21S11, D7S820, vWA, FGA, and amelogenin (a gender marker) |
| Informative Markers | Markers that can distinguish the recipient's DNA from the donor's DNA in future post-transplant tests |
| Recipient Baseline Profile | Confirms 100% recipient DNA before transplant, used as the reference point for all later comparisons |
Why Is a Chimerism by STR (Pretransplant) Test Done?
This test is a mandatory pre-transplant step rather than a symptom-driven investigation. It is ordered as part of the preparation process for patients about to undergo allogeneic transplantation.
Common Situations That Require This Test
- Patient scheduled for allogeneic haematopoietic stem cell transplant (HSCT)
- Patient scheduled for allogeneic bone marrow transplant
- Need to establish a recipient DNA baseline before transplant conditioning begins
- Requirement to identify informative STR markers for post-transplant monitoring
- Clinical protocol mandating pretransplant genotyping for engraftment tracking
Conditions This Test Can Help Detect
The Chimerism by STR (Pretransplant) test is required for patients being treated for a range of serious blood and immune disorders. These include:
- Leukaemia (including acute myeloid leukaemia)
- Lymphoma
- Myelodysplastic syndrome (MDS), a disorder where bone marrow does not produce enough healthy blood cells
- Aplastic anaemia and severe aplastic anaemia (SAA)
- Thalassaemia
- Congenital immune deficiencies (inherited conditions affecting the immune system)
Chimerism by STR (Pretransplant) Test for Chronic Disease Monitoring
Serial chimerism testing after transplantation is a key tool for long-term monitoring of treatment outcomes. By comparing post-transplant samples with the pretransplant baseline established by this test, doctors can track whether donor cells are engrafting successfully, identify early signs of relapse, or detect potential graft rejection. General guidance suggests monitoring every three months in the first year, every six months in the second year, and annually for at least five years after transplant.
How to Prepare and What to Expect
No special preparation is needed for this test. The steps below explain what happens from the time of your appointment to sample dispatch.
Do You Need to Fast?
No. Fasting is not required for the Chimerism by STR test. You may eat and drink normally before your sample is collected.
Practical Tips Before Your Test
- Bring a detailed clinical history, including your diagnosis, previous test results, and treatment records, as this is required for the test.
- Inform your doctor or the phlebotomist about any recent blood transfusions, as these can affect the baseline DNA profile.
- Mention any previous organ or bone marrow transplants to your medical team.
- Arrange for the sample to reach the laboratory as soon as possible after collection; it should arrive within seven days.
- Follow all pre-transplant instructions from your transplant team.
Step-by-Step Procedure
- A trained phlebotomist will clean a small area on your arm and collect approximately 2 mL of blood into a lavender-topped EDTA tube (a tube containing a substance that prevents the blood from clotting).
- The needle is removed, and a small bandage is applied. The procedure takes less than a minute and causes minimal discomfort.
- The sample is labelled, stored at 2 to 8 degrees Celsius (refrigerated, not frozen), and packaged for dispatch to the laboratory.
- At the laboratory, DNA is extracted from your blood sample.
- A technique called PCR (polymerase chain reaction, which amplifies or copies specific DNA regions) is used to analyse your STR markers using fragment analysis.
- The STR profile is recorded as your unique genetic baseline and stored for comparison with all future post-transplant chimerism tests.
Factors That Can Affect Accuracy
- Recent blood transfusions before sample collection, which may introduce donor DNA into the baseline sample
- Sample contamination or poor sample quality during collection
- DNA degradation if the sample is not stored or transported correctly
- Rare DNA sequence variations that may interfere with marker detection
- Very small cell populations (less than 2 to 5% of the total) may not be detected by current technology
Understanding Your Chimerism by STR (Pretransplant) Test Results
The pretransplant result is not a pass or fail outcome. It establishes a genetic reference point used by your doctor for all future comparisons. The table below shows what to expect:
| Parameter | Expected Pretransplant Result | Notes |
|---|---|---|
| Recipient STR Profile | 100% recipient DNA | Confirms the baseline genetic fingerprint |
| Informative Markers Identified | 3 or more markers recommended | More informative markers improve accuracy of post-transplant monitoring |
Post-transplant results (using this baseline) are classified as full chimerism (95 to 99% or more donor DNA), mixed chimerism (a combination of donor and recipient cells), or potential graft rejection (increasing percentage of recipient cells over time).
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.
Lupin Diagnostics Chimerism by STR (Pretransplant) Test Price and Home Collection
The Chimerism by STR (Pretransplant) test is available at Lupin Diagnostics starting at ₹9,000, with home sample collection available across cities. The city-wise price breakdown is listed below.
| City | Approximate Price (₹) |
|---|---|
| BHOPAL | 9000 |
| CHENNAI | 9000 |
| HYDERABAD | 9000 |
| KOLKATA | 9000 |
| NAVI MUMBAI | 9000 |
| PUNE | 9000 |
Disclaimer: Prices are indicative and may vary by location. Please confirm the current price at the time of booking.
How to Book
Select the Chimerism by STR 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
Lupin Diagnostics offers home sample collection for the Chimerism by STR (Pretransplant) test across multiple cities. All samples are processed in NABL-accredited laboratories by experienced molecular diagnostics teams. Your digital report is made accessible via email or WhatsApp once ready.
Frequently Asked Questions
The Chimerism by STR (Pretransplant) test maps the recipient's unique DNA profile before an allogeneic transplant. This baseline is essential for all post-transplant monitoring, as it allows doctors to distinguish between the recipient's and donor's cells in future tests and assess whether the transplant has been successful.
Without a pre-transplant baseline, it would be impossible to tell whether cells found after the transplant belong to the donor or to the recipient. The pre-transplant sample creates a genetic reference point that makes all post-transplant comparisons possible and meaningful.
A small 2 mL blood sample is collected from a vein in the arm into a lavender-topped EDTA tube. The sample is stored refrigerated (2 to 8 degrees Celsius) and must reach the laboratory within seven days of collection.
The report for the Chimerism by STR test is typically delivered within 15 days. Turnaround times may vary depending on the schedule and laboratory processing.
No fasting is required. You can eat and drink as normal before your sample is collected. The only important preparation step is to bring your clinical history to the appointment, as this is required for the test.
STR-based chimerism testing has a reported sensitivity of approximately 1 to 5%, making it the most widely used method for chimerism analysis. Cell populations making up less than 2 to 5% of the total may not be detected with current technology, which is why serial monitoring over time is important.
Chimerism by STR (Pretransplant) Test: Booking, Price, and Results
