C4d Test: Booking, Price, and Results
About C4d Test: Booking, Price, and Results
| Field | Value |
|---|---|
| Also Known As | Complement Component 4d, Complement Fragment 4d, C4d IHC, C4d ELISA |
| Sample Type | Tissue biopsy (for IHC) or venous blood (plasma/serum for ELISA) |
| Fasting Required | No |
| Report Time | 3 to 7 working days |
| Recommended For | Adults and children; transplant recipients and patients with suspected autoimmune conditions |
| Price | Starting at ₹1920 |
What Is a C4d Test?
The C4d test measures a small fragment of the immune system's complement protein, produced when the body activates its defence response. Doctors commonly order this test for patients who have received an organ transplant or who may have an autoimmune condition. Depending on the clinical situation, the sample may be a blood draw or a tissue biopsy. The test is also referred to as the Complement Component 4d or the Complement Fragment 4d test.
What Does a C4d Test Measure?
The C4d test detects a breakdown fragment of complement component C4, which is part of the body's immune defence system. Unlike the parent protein C4, this fragment is produced only when the complement system is actively triggered. Its presence in the blood or tissue indicates that an immune reaction has occurred.
The test is performed using one of two methods:
C4d tissue staining (IHC): Checks for C4d deposits in the small blood vessels of a transplanted organ, using a technique called immunohistochemistry.
C4d plasma measurement (ELISA): Quantifies the level of C4d circulating in the blood using an enzyme-based lab technique.
Why Is a C4d Test Done?
The C4d test is ordered when a doctor needs to understand whether the immune system is attacking a transplanted organ or driving an autoimmune condition.
Common Symptoms That May Require This Test
A doctor may recommend this test when a patient presents with the following symptoms:
- Fever of 100°F or above
- Flu-like symptoms including body aches, nausea, and vomiting
- Fluid retention and noticeable swelling
- Sudden or abnormal weight gain within 24 hours
- Reduced urine output
- Tenderness around the transplanted kidney area
- Joint pain, skin rashes, or persistent fatigue
Conditions This Test Can Help Detect
This test helps identify a range of immune-related conditions, including:
- Antibody-mediated rejection in kidney and heart transplants
- Systemic lupus erythematosus (SLE), an autoimmune condition where the immune system attacks healthy tissue
- Lupus nephritis, which is kidney inflammation caused by lupus
- Rheumatoid arthritis and glomerulonephritis (a form of kidney inflammation)
- Neuromyelitis optica spectrum disorder (NMOSD) and acute disseminated encephalomyelitis (ADEM), both involving the central nervous system
C4d Test for Chronic Disease Monitoring
The C4d test is a useful marker for tracking disease activity in conditions such as SLE. Studies show that C4d levels shift more clearly between active and inactive disease phases than other complement markers. In lupus nephritis patients, falling C4d levels after treatment are linked to a positive clinical response, making the test a practical tool for monitoring how well treatment is working.
How to Prepare and What to Expect
Preparation for this test is straightforward, though correct sample handling is critical for accurate results.
Do You Need to Fast?
No, fasting is not required for the C4d blood test. You may eat and drink normally before your appointment. If you are also having other tests done on the same day, check with your doctor whether any of those require fasting.
Practical Tips Before Your Test
Keep the following in mind before you go for your test:
- Inform your doctor about all medications you are taking, particularly immunosuppressants if you are a transplant recipient.
- Stay well hydrated before a blood draw.
- Wear comfortable clothing with easy access to the inner arm.
- Avoid strenuous physical activity on the day of collection.
- If giving a blood sample, it must be processed quickly, so arrange your appointment accordingly.
Step-by-Step Procedure
The collection process differs slightly depending on whether a blood sample or tissue sample is needed.
For a blood-based C4d test, here is what to expect:
- A trained phlebotomist cleans the inner arm and draws blood from a vein using a fine needle.
- The blood is collected into a special EDTA tube to prevent the sample from degrading.
- The tube is kept cool and centrifuged within about 30 minutes to separate the plasma.
- The plasma is carefully stored at a low temperature to preserve the sample's integrity.
- The sample is sent to the laboratory, where the C4d level is measured using the ELISA technique.
- Results are reviewed by the laboratory team and dispatched to your doctor within the stated turnaround time.
Factors That Can Affect Accuracy
Several factors may influence how reliable your results are:
- Delayed sample processing or improper storage temperature
- Haemolysis (rupture of red blood cells) during collection
- Use of incorrect collection tubes or anticoagulants
- Active infections, which can alter complement levels independently
- Immunosuppressive medications, which may reduce complement activity
Understanding Your C4d Test Results
Results from this test should always be discussed with your treating doctor, who will consider your full medical history and clinical context. The table below offers a general guide to interpreting results.
| Method | Normal Result | Elevated or Positive Result |
|---|---|---|
| C4d Tissue Staining (IHC) | Negative; no staining in blood vessel walls | Positive staining indicates complement activation; may suggest antibody-mediated rejection |
| C4d Plasma (ELISA) | Negligible or undetectable in healthy individuals | Raised levels may indicate active SLE, lupus nephritis, transplant rejection, or other inflammatory conditions |
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 affect how results should be read:
- In ABO-incompatible transplants, C4d may be detected even without active rejection. This pattern can reflect graft accommodation rather than immune attack.
- Active infections can raise complement activity and affect C4d levels independently of transplant or autoimmune status.
- Immunosuppressive medications may reduce complement activation, which can influence results over time.
How to Maintain Healthy Levels
The following general wellness habits support immune health:
- Follow your prescribed treatment plan consistently, especially if you are a transplant recipient or managing an autoimmune condition.
- Eat a balanced diet and get adequate sleep to support normal immune function.
- Attend follow-up appointments regularly so your doctor can track any changes over time.
Lupin Diagnostics C4d Test Price and Home Collection
The C4d test price at Lupin Diagnostics starts at ₹2,500, and home sample collection is available for the blood-based ELISA version of this test.
| City | Approximate Price (₹) |
|---|---|
| Mumbai | ₹2,500 |
| Delhi/NCR | ₹3,000 |
| Bangalore | ₹3,500 |
| Chennai | ₹3,000 |
| Hyderabad | ₹3,000 |
| Kolkata | ₹3,000 |
| Pune | ₹3,000 |
| Ahmedabad | ₹3,000 |
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
Home collection for the C4d blood test is available across cities through Lupin Diagnostics' trained phlebotomists. Please note that tissue biopsy samples for C4d IHC must be collected at a clinical facility. All samples are processed in NABL-accredited laboratories, and digital reports are accessible via email or WhatsApp.
Frequently Asked Questions
The C4d test is primarily used to detect antibody-mediated rejection in organ transplant patients. When a transplanted kidney or heart is under immune attack, C4d deposits appear in the small blood vessels of the organ. The test is also used to assess and monitor autoimmune conditions such as SLE.
The C4 test measures the total amount of complement protein C4 in the blood. The C4d test measures a fragment produced only when C4 is broken down during active complement activation. This makes C4d a more specific indicator of an ongoing immune response.
No fasting is needed before the C4d test. You can eat and drink as usual. However, correct sample handling after collection is very important for reliable results.
Yes, the C4d test is a useful marker in diagnosing and monitoring SLE. Studies show it has greater sensitivity and specificity than low serum complement levels for detecting lupus. It is typically used alongside other tests such as ANA and anti-dsDNA for a complete assessment.
A positive C4d IHC result in transplant tissue suggests that antibodies are activating the complement system within the organ. The stronger the staining, the more likely antibody-mediated rejection is occurring. Your doctor will use this finding alongside other clinical information to decide on the next steps.
For the IHC version of this test, a small tissue sample is obtained from the transplanted organ via a biopsy performed in a clinical setting. The tissue is then processed, stained with specific antibodies, and examined under a microscope in the laboratory.
Home collection is available for the blood-based C4d ELISA test. A certified phlebotomist can collect your blood sample at your doorstep. If the doctor has requested a tissue biopsy for C4d IHC, the procedure must be performed at a medical centre by a qualified professional.
C4d Test: Booking, Price, and Results
