IHC Marker-TdT (Monoclonal) Test
About IHC Marker-TdT (Monoclonal) Test
| Field | Value |
|---|---|
| Also Known As | TdT IHC, Terminal Deoxynucleotidyl Transferase IHC, DNTT Immunostain, TdT Monoclonal Antibody Test |
| Sample Type | FFPE tissue block (formalin-fixed, paraffin-embedded tissue) |
| Fasting Required | No |
| Report Time | 3 Days |
| Recommended For | Adults and children of all ages ordered when a haematological malignancy is suspected |
| Price | Starting at ₹1,920 |
What Is an IHC Marker-TdT (Monoclonal) Test?
The IHC marker-TdT test is a specialised laboratory test that detects the presence of an enzyme called Terminal Deoxynucleotidyl Transferase (TdT) in tissue samples. TdT is found in immature, early-stage blood cells and is used as a marker to identify certain blood cancers. Also known as the TdT IHC or DNTT Immunostain, this test uses the immunohistochemistry (IHC) method, which applies a monoclonal antibody to a tissue section to reveal the presence or absence of the TdT protein. A pathologist examines the stained tissue to arrive at a conclusion.
What Does an IHC Marker-TdT (Monoclonal) Test Measure?
This test detects and evaluates TdT protein expression in tissue. The table below explains the single parameter assessed.
| Parameter | What It Means |
|---|---|
| TdT Expression | Identifies whether immature (precursor) lymphoid or haematopoietic cells are present in the tissue sample |
TdT is an enzyme that adds nucleotides (the building blocks of DNA) to the ends of DNA strands in immature blood cells. Its presence in a tissue sample indicates the existence of early-stage, undeveloped cells, which can signal certain types of leukaemia or lymphoma.
Why Is an IHC Marker-TdT (Monoclonal) Test Done?
Doctors order this test when a patient shows signs that may point to a blood cancer involving immature lymphoid cells. It is typically part of a broader diagnostic workup alongside other investigations.
Common Symptoms That May Require This Test
A doctor may recommend the IHC marker-TdT test when a patient presents with one or more of the following:
- Persistent fatigue without a clear cause
- Easy or unexplained bruising and bleeding
- Frequent or recurring infections
- Fever and night sweats
- Unintentional weight loss
- Enlarged lymph nodes (swollen glands in the neck, armpits, or groin)
- Bone pain or pale skin
Conditions This Test Can Help Detect
The TdT IHC test assists pathologists in identifying or ruling out the following conditions:
- Acute lymphoblastic leukaemia (ALL), including pre-B and pre-T cell types
- Lymphoblastic lymphoma (LBL)
- Burkitt lymphoma (typically TdT-negative, helping to rule it out)
- Certain cases of acute myeloid leukaemia (AML)
- Chronic myeloid leukaemia (CML) in blast crisis
How to Prepare and What to Expect
No special patient preparation is needed before this test, as it is performed on a tissue sample rather than a blood or urine sample. However, there are a few important points to be aware of before your appointment.
Do You Need to Fast?
No fasting is required. This test analyses a tissue sample that is collected during a separate biopsy procedure, so food and drink have no bearing on the result.
Practical Tips Before Your Test
Keep the following in mind before the test is carried out:
- Bring a detailed clinical history, including your symptoms, previous test results, and relevant medical records, as this is required for the test.
- Inform your doctor about any ongoing medications, particularly chemotherapy drugs, as these can affect TdT levels.
- Understand that the IHC staining is performed on an existing tissue block; a biopsy must be collected first by a trained clinician.
- This test is often done alongside other investigations such as a bone marrow aspiration, complete blood count (CBC), and immunophenotyping tests.
Step-by-Step Procedure
Here is what the overall process involves, from tissue collection to result:
- A trained clinician collects a tissue biopsy, most often from the bone marrow or a lymph node, in a clinical setting.
- The collected tissue is fixed in formalin (a preservative solution) and embedded in paraffin wax to form an FFPE block, which is then sent to the laboratory.
- The laboratory cuts very thin sections from the tissue block and places them on specially coated glass slides.
- Using the immunohistochemistry method, a monoclonal antibody targeting the TdT protein is applied to the tissue section, and the slide is processed through a staining technique.
- A qualified pathologist examines the stained slides under a microscope, assessing whether cells show TdT positivity or negativity.
- The final report is prepared with the pathologist's interpretation and delivered within the turnaround time.
Factors That Can Affect Accuracy
Several factors can influence the reliability of the test result:
- Improper tissue fixation (tissue should be fixed in formalin for 6 to 72 hours)
- Delayed processing of paraffin sections (sections are best cut within six weeks of embedding)
- Poor tissue preservation or handling during transport
- Prior or ongoing chemotherapy, which may alter TdT expression in cells
- The age of the cut paraffin section, which can reduce immunoreactivity over time
Understanding Your IHC Marker-TdT (Monoclonal) Test Results
Results from this test are reported as either positive or negative and must always be reviewed by a qualified pathologist and your treating doctor. The table below outlines how results are generally interpreted.
| Result | Typical Implication |
|---|---|
| TdT Positive | Immature lymphoid or precursor cells are present; may suggest ALL, LBL, or certain AML cases |
| TdT Negative | Mature lymphoid cells or non-haematological tissue; seen in Burkitt lymphoma and normal mature tissues |
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 circumstances can influence how results are read:
- Ongoing or recent chemotherapy can lower TdT expression in cells, potentially affecting the test outcome. Your doctor will account for this when reviewing your results.
- TdT-negative variants of lymphoblastic lymphoma have been associated with a more aggressive disease course, making accurate interpretation by an experienced pathologist particularly important.
How to Maintain Healthy Levels
Because TdT is a diagnostic marker for cancer classification rather than a routine health parameter, lifestyle changes do not directly influence its expression. General guidance includes:
- Follow your oncologist's or haematologist's care plan closely.
- Attend all scheduled follow-up consultations and investigations as advised.
- Maintain general health through adequate nutrition, hydration, and rest during treatment.
Lupin Diagnostics IHC Marker-TdT (Monoclonal) 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, as home collection is not available for tissue-based investigations of this nature.
| City | Approximate Price (₹) |
|---|---|
| BHOPAL | 1920 |
| CHENNAI | 1920 |
| HYDERABAD | 1920 |
| KOLKATA | 1920 |
| NAVI MUMBAI | 1920 |
| PUNE | 1920 |
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 IHC marker-TdT test online through Lupin Diagnostics:
- Select the test on the Lupin Diagnostics website.
- Choose your city and preferred centre location.
- Visit the centre at your scheduled time, bringing your FFPE tissue block and clinical history documentation.
- Receive your report via email or WhatsApp within the stipulated turnaround time.
Frequently Asked Questions
This test helps pathologists classify leukaemias and lymphomas by detecting the TdT enzyme in tissue samples. It is particularly valuable for identifying acute lymphoblastic leukaemia and lymphoblastic lymphoma and for distinguishing these from other blood cancers such as Burkitt lymphoma.
Yes. The IHC marker-TdT test procedure is performed on tissue that has already been collected through a biopsy, such as a bone marrow or lymph node biopsy. The IHC staining is carried out on the processed tissue block in the laboratory.
No. Because the test requires a tissue biopsy collected by a trained clinician in a clinical setting, home collection is not applicable. You will need to visit a Lupin Diagnostics centre.
Results are typically delivered within 3 days at Lupin Diagnostics. The turnaround time accounts for tissue processing, staining, and review by a qualified pathologist.
A positive result indicates the presence of immature lymphoid cells in the tissue sample. This finding is associated with conditions such as acute lymphoblastic leukaemia or lymphoblastic lymphoma. Your doctor will use this result alongside other investigations to arrive at a diagnosis.
Yes, in some cases. While TdT positivity is seen in around 90 to 95% of lymphoblastic leukaemia and lymphoma cases, TdT-negative variants do exist. A negative result does not entirely rule out a haematological malignancy, and your doctor will consider all available clinical and laboratory information.
Yes. A detailed clinical history, including your symptoms, previous investigation reports, and any relevant medical records, is required when submitting your sample. This information is essential for accurate interpretation by the pathologist.
IHC Marker-TdT (Monoclonal) Test
