IHC Marker – TdT Test: Booking, Price, and Results
About IHC Marker – TdT Test: Booking, Price, and Results
| Field | Value |
|---|---|
| Also Known As | Terminal Deoxynucleotidyl Transferase IHC, TdT Immunostain, DNTT IHC Marker |
| Sample Type | Tissue biopsy (FFPE block — formalin-fixed, paraffin-embedded tissue) |
| Fasting Required | No – this test is performed on a tissue sample, not a blood sample |
| Report Time | 7 days |
| Recommended For | All genders and ages; primarily ordered when a blood cancer is suspected |
| Price | Starting at ₹1,920 |
What Is an IHC Marker – TdT Test?
The IHC marker – TdT test detects the presence of an enzyme called terminal deoxynucleotidyl transferase (TdT) in tissue samples. TdT is normally found only in immature lymphoid cells, which are early-stage white blood cells that develop in the bone marrow and thymus. Doctors order this test when they suspect certain blood cancers, such as acute lymphoblastic leukaemia (ALL) or lymphoblastic lymphoma (LBL). The test is also known as the TdT immunostain or the DNTT IHC marker test.
What Does an IHC Marker – TdT Test Measure?
The IHC marker – TdT test uses a laboratory technique called 'immunohistochemistry' (IHC). This method uses specially prepared antibodies to detect and highlight specific proteins within tissue sections viewed under a microscope. In this case, the antibody targets the TdT enzyme. The table below explains what the test looks for and how the findings are interpreted.
| Parameter | Normal Finding | Clinical Significance |
|---|---|---|
| TdT Expression | Negative (absent) in mature lymphoid cells | Mature, healthy white blood cells do not carry TdT |
| TdT Positivity Threshold | 20% or more blast cells staining positive | Considered clinically significant for diagnostic purposes |
Normally, mature lymphoid cells do not express TdT. When it is detected in a significant proportion of cells, this suggests the presence of immature, abnormal cells that may be associated with leukaemia or lymphoma. A pathologist examines the stained tissue slides and reports whether TdT is expressed and, if so, in what proportion of cells.
Why Is an IHC Marker – TdT Test Done?
This test is a specialised diagnostic tool used when a doctor suspects certain blood or lymphoid cancers. It is not a routine screening test and is always ordered in the context of other clinical findings.
Common Symptoms That May Require This Test
A doctor may recommend an IHC TdT test when a patient presents with several of the following symptoms:
- Persistent tiredness or weakness
- Unexplained shortness of breath
- Pale skin or pallor
- Persistent fever or recurrent infections
- Easy bruising or unusual bleeding
- Swollen lymph nodes in the neck, armpits or groin
- Bone or joint pain
- Abdominal fullness or discomfort
- Unexplained weight loss
Conditions This Test Can Help Detect
The TdT immunostain test is used to help confirm or rule out the following conditions:
- Acute lymphoblastic leukaemia (ALL): TdT is positive in around 95% of ALL cases (excluding Burkitt leukaemia)
- B cell and T cell lymphoblastic leukaemia or lymphoma: Both types express TdT in approximately 95% of cases
- Acute myeloid leukaemia (AML): Around 20% of AML cases may express TdT
- Chronic myeloid leukaemia (CML) in blast crisis: A subset of cases may show TdT positivity
- Burkitt lymphoma: TdT is typically absent, helping to distinguish it from lymphoblastic lymphoma
How to Prepare and What to Expect
As this test is performed on a tissue sample rather than a blood sample, your preparation will focus on documentation and communication with your medical team.
Do You Need to Fast?
No, fasting is not required for the IHC marker – TdT test. The test is carried out on a tissue block obtained through a biopsy procedure, so food and drink intake before the test does not affect the results. However, if your doctor has also ordered other blood tests, those may have their own fasting requirements.
Practical Tips Before Your Test
Please keep the following in mind before submitting your sample:
- Bring a detailed clinical history, including your symptoms, previous test results and family history, as this is required for the test.
- Carry your doctor's referral letter, which should clearly mention the biopsy site.
- Bring any existing histopathology reports if you are submitting a paraffin-embedded tissue block from a prior biopsy.
- Include relevant imaging reports such as CT scans, MRI, PET scans or X-rays.
- Inform your doctor about all medications you are currently taking, including supplements.
Step-by-Step Procedure
The IHC TdT test procedure involves tissue collection followed by laboratory processing. Here is what to expect:
- A doctor performs a biopsy to collect the tissue sample. This may be a needle biopsy, incisional biopsy or a bone marrow biopsy, depending on the suspected site of disease. No additional sample collection is needed for the IHC test itself.
- The collected tissue is fixed in formalin and embedded in a paraffin block (referred to as an FFPE block), or thin sections are cut from an existing block and placed on glass slides.
- The block or prepared tissue sections are submitted to the laboratory along with your clinical history.
- In the lab, thin tissue sections are stained using anti-TdT antibodies through the immunohistochemistry method.
- A pathologist examines the stained slides under a microscope and assesses whether TdT is present and in how many cells.
- A detailed report is prepared and delivered within 7 days of sample receipt.
Factors That Can Affect Accuracy
The following factors may influence the reliability of the IHC marker – TdT test:
- Age of the tissue section: paraffin sections should ideally be cut within 6 weeks for optimal staining
- Poor or inconsistent tissue fixation before processing
- Certain chemotherapy drugs, which can reduce TdT expression in cancer cells
- Inadequate clinical history provided at the time of submission
- Improper handling or storage of the tissue block before dispatch
Understanding Your IHC Marker – TdT Test Results
Results from this test must always be reviewed by a qualified pathologist or haematologist alongside your full clinical picture, including other laboratory findings and imaging reports. The table below provides a general guide to interpreting findings.
| Finding | What It May Indicate |
|---|---|
| TdT Negative | No TdT detected, consistent with mature lymphoid cells or absence of lymphoblastic disease |
| TdT Positive (less than 20% blasts) | Low-level expression; clinical significance depends on context |
| TdT Positive (20% or more blasts) | Clinically significant; consistent with lymphoblastic leukaemia or lymphoma (LBL) |
| TdT Positive (greater than 40% blasts) | Strongly associated with acute lymphoblastic leukaemia (ALL) |
| TdT Positive in a minority of blasts | May be seen in around 20% of acute myeloid leukaemia (AML) cases |
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
Certain situations can alter test findings and should be communicated to your doctor before the test.
Chemotherapy treatment can lower TdT expression in cancer cells. In patients with T-cell acute lymphoblastic leukaemia or lymphoma who have received chemotherapy, TdT may be downregulated in residual disease, which can affect interpretation. Your pathologist will factor in treatment history when reviewing results.
Sample quality also plays a role. Tissue that was not properly fixed or stored may produce weaker staining, which can affect the accuracy of the result.
How to Maintain Healthy Levels
TdT expression is determined by the biological nature of cells, not by lifestyle choices. However, the following general steps support your overall health during the diagnostic process:
- Report any new or worsening symptoms to your doctor promptly, as early investigation leads to better outcomes.
- Attend all follow-up appointments and provide complete information about your medical history and current medications.
- Maintain a balanced diet and stay well hydrated to support your body's general wellbeing during any diagnostic workup.
Lupin Diagnostics IHC Marker – TdT Test Price
The IHC marker – TdT test cost at Lupin Diagnostics starts at ₹1,920. This test requires a visit to a Lupin Diagnostics centre; home collection is not available because the sample must be obtained through a medical biopsy procedure. The city-wise price breakdown is provided below for your reference.
| City | Approximate Price (₹) |
|---|---|
| BHOPAL | 1920 |
| CHENNAI | 1920 |
| HYDERABAD | 1920 |
| KOLKATA | 1920 |
| NAVI MUMBAI | 1920 |
| PUNE | 1920 |
Disclaimer: Prices are indicative and may vary by location. Please confirm the current price at the time of booking.
How to Book
IHC marker – TdT test online booking with Lupin Diagnostics is straightforward:
- Select the test on the Lupin Diagnostics website.
- Choose your city and preferred centre location.
- Visit the centre at your scheduled time for sample submission.
- Receive your report via email or WhatsApp within 7 days of sample receipt.
Frequently Asked Questions
The IHC marker – TdT test is used to help diagnose and classify certain blood and lymphoid cancers, particularly acute lymphoblastic leukaemia (ALL) and lymphoblastic lymphoma (LBL). It detects the TdT enzyme in tissue samples obtained through biopsy. Additional tests are usually needed to complete the diagnosis.
The test itself involves no pain because it is performed on a tissue sample in the laboratory. However, the biopsy procedure used to collect the tissue may cause some discomfort. Your doctor will discuss what to expect before the procedure and can advise on pain management if needed.
Tissue is collected by your treating doctor through a needle biopsy, incisional biopsy or surgical procedure. The IHC test is then carried out on this previously collected tissue. No additional sample collection is needed specifically for the IHC marker – TdT test itself.
Yes, to an extent. The TdT immunostain test is particularly useful for identifying immature lymphoid cancers such as ALL and distinguishing lymphoblastic lymphoma from mature lymphomas like Burkitt lymphoma. However, a full classification of leukaemia or lymphoma requires additional markers and tests alongside TdT.
The IHC marker – TdT test is typically ordered alongside a complete blood count (CBC), bone marrow aspiration and other immunophenotyping tests. Together, these investigations give doctors a fuller picture of the type and extent of any blood cancer present.
No. TdT levels reflect the activity of immature lymphoid cells in your body and are not influenced by diet, exercise or other lifestyle factors. If your results are abnormal, your doctor will guide you on appropriate next steps.
The IHC marker – TdT test report is typically ready within 7 days of the laboratory receiving the tissue sample. Results will be sent to you digitally via email or WhatsApp, and you should review them with your doctor or a specialist pathologist.
IHC Marker – TdT Test: Booking, Price, and Results
