C1 Esterase Inhibitor Test: Booking, Price, and Results
About C1 Esterase Inhibitor Test: Booking, Price, and Results
| Field | Value |
|---|---|
| Also Known As | C1-INH Test, C1 Inhibitor Test, Complement C1 Esterase Inhibitor, C1-INH Antigen, C1-INH Functional Assay |
| Sample Type | Serum (venous blood) |
| Fasting Required | No fasting required |
| Report Time | 10 days |
| Recommended For | All ages and genders, particularly those with unexplained recurrent swelling, a family history of hereditary angioedema, or suspected autoimmune conditions |
| Price | Starting at ₹4,000 |
What is a C1 Esterase Inhibitor Test?
The C1 Esterase Inhibitor Test measures the level and activity of a protein called C1 esterase inhibitor (C1-INH) in your blood. This protein plays a key role in regulating your immune and inflammatory responses. Doctors typically order this test when a patient has unexplained recurrent swelling or a family history of hereditary angioedema (HAE), a condition that causes sudden swelling in various parts of the body.
Also referred to as the C1 Inhibitor Test or C1-INH Antigen test, it requires a small blood sample drawn from a vein.
What Does a C1 Esterase Inhibitor Test Measure?
This test evaluates two key aspects of the C1-INH protein in your blood. Both measurements together give a clearer picture of how well your immune regulation is working.
| Parameter | What It Assesses |
|---|---|
| C1-INH Protein Level (Quantitative) | The actual amount of C1-INH protein present in the blood |
| C1-INH Functional Activity | How effectively the C1-INH protein performs its role in controlling inflammation |
C1-INH regulates several pathways in the body, including the complement system (a group of proteins that support immune defence), the kallikrein-kinin pathway (which produces bradykinin, a chemical that triggers swelling), and parts of the clotting system.
Why is a C1 Esterase Inhibitor Test Done?
This test helps doctors identify the cause of unexplained or recurring swelling and assess immune system function. Below are the key reasons it may be ordered.
Common Symptoms That May Require This Test
Your doctor may recommend this test if you experience any of the following symptoms.
- Recurrent swelling of the hands, feet, or face with no clear cause
- Swelling of the throat or tongue
- Abdominal pain or vomiting without an obvious cause
- Breathing difficulty related to episodes of swelling
- Non-itchy skin swelling that lasts for several days
Conditions This Test Can Help Detect
This test can assist in identifying several conditions related to immune regulation.
- Hereditary angioedema (HAE) Type I, where both C1-INH levels and function are reduced
- Hereditary angioedema (HAE) Type II, where levels may be normal, but the protein does not function correctly
- Acquired C1 inhibitor deficiency, which can be linked to conditions such as lymphoma, myeloma, or autoimmune diseases
- Systemic lupus erythematosus (SLE) and other autoimmune conditions
C1 Esterase Inhibitor Test for Chronic Disease Monitoring
The C1 Esterase Inhibitor Test is used not only to diagnose HAE but also to monitor how well a patient responds to ongoing therapy. For those living with HAE or related conditions, periodic testing helps track protein levels and adjust management accordingly. It is also recommended for patients with unexplained inflammatory episodes who are under long-term medical review.
How to Prepare and What to Expect
No special preparation is needed before this test. The following sections explain what to expect on the day of your appointment.
Do You Need to Fast?
No, fasting is not required before the C1 Esterase Inhibitor Test. You may eat and drink normally before your sample is collected.
Practical Tips Before Your Test
A few simple steps will help ensure your sample is collected smoothly and that the result is as accurate as possible.
- Bring a detailed clinical history, including your symptoms, previous test results, and family history, as this is required for the test
- Inform your doctor about all medications and supplements you are currently taking, as some can affect results
- Stay well hydrated before your appointment
- Inform the laboratory if you have had any recent illness or infection
Step-by-Step Procedure
- You will be seated comfortably, and the collection site (usually the inside of your elbow) will be cleaned with an antiseptic.
- A trained phlebotomist will insert a small needle into a vein to draw approximately 3 ml of blood into a gel tube.
- The needle is removed, and a small cotton pad or bandage is applied to the site.
- The serum is separated from the blood cells within 30 to 60 minutes of collection.
- The sample is transferred to a transport tube and stored at refrigeration temperature (2 to 8 degrees Celsius) to preserve its integrity.
- The sample is dispatched to the laboratory for analysis using the EIA (enzyme immunoassay) method.
Factors That Can Affect Accuracy
- Haemolysis (breakdown of red blood cells in the sample)
- Gross lipaemia (very high fat content in the blood)
- Improper sample handling or storage
- Microbial contamination of the sample
- Use of certain medications, including oral contraceptives or oestrogen-containing preparations
Understanding Your C1 Esterase Inhibitor Test Results
Your results should always be reviewed by your doctor alongside your symptoms and medical history. The table below shows general reference ranges for this test.
| Parameter | Normal Range |
|---|---|
| C1-INH Level (Quantitative) | 21 to 39 mg/dL (0.21 to 0.39 g/L) |
| C1-INH Functional Activity | 70 to 130% of normal |
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.
Low C1-INH levels or reduced functional activity may be associated with conditions such as HAE, lupus, kidney disease, or nutritional deficiencies. Elevated levels, while less common, may occur in HAE Type II or in the context of inflammation or immune activation.
Results During Special Conditions
Certain health states and medications can influence your results. Your doctor will factor these in during interpretation.
C1-INH levels can decline during the late stages of pregnancy and may also be reduced in liver disease, certain malignancies, and following extracorporeal circulation therapy.
In addition, use of oestrogen-containing medications (including oral contraceptives) may reduce C1 inhibitor function, which is worth disclosing before the test.
How to Maintain Healthy Levels
While C1-INH levels are largely determined by genetics and underlying health conditions, the following general wellness habits support a healthy immune system.
- Eat a balanced diet and get adequate sleep to support overall immune function
- Avoid known triggers of swelling episodes, such as physical trauma or high levels of stress
- Attend regular follow-up appointments with your specialist if you have been diagnosed with HAE or a related condition
Lupin Diagnostics C1 Esterase Inhibitor Test Price and Home Collection
The C1 Esterase Inhibitor Test is available at Lupin Diagnostics starting at ₹4,000, with home sample collection offered across multiple cities in India.
| City | Approximate Price (₹) |
|---|---|
| BHOPAL | 4000 |
| CHENNAI | 4000 |
| HYDERABAD | 4000 |
| KOLKATA | 4000 |
| NAVI MUMBAI | 4000 |
| PUNE | 4000 |
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
The C1 Esterase Inhibitor Test home collection service is available across cities, making it convenient to get tested without visiting a centre. All samples are processed in NABL-accredited laboratories, and your report is delivered digitally, accessible via email or WhatsApp.
Frequently Asked Questions
The C1 Esterase Inhibitor Test checks the level and function of a protein that helps regulate the immune system and control inflammation. When this protein is low or not working correctly, it can cause a condition called angioedema, which involves sudden swelling of the face, throat, abdomen, or limbs.
This test is recommended for people who experience unexplained recurrent swelling, particularly in the face, throat, or abdomen. It is also advised for those with a family history of hereditary angioedema or other conditions affecting the immune or complement systems.
No, fasting is not required. You can eat and drink as normal before the blood draw. No special preparation is needed apart from bringing your clinical history.
In Type I hereditary angioedema (HAE), which accounts for around 85% of cases, both the amount and function of C1-INH are below normal. In Type II HAE, the quantity of the protein may be normal or even elevated, but the protein does not function properly, so swelling episodes still occur.
Measuring only the protein level may miss cases where the protein is present but inactive, as seen in HAE Type II. Testing both the quantity and function together gives a more complete picture and helps doctors make a more accurate diagnosis.
Yes, some medications and supplements can influence results. Oestrogen-containing medicines, including some oral contraceptives, may reduce C1 inhibitor function. Always inform your doctor about everything you are taking before the C1 Inhibitor Test is carried out.
Doctors often order a C4 complement test alongside the C1 Esterase Inhibitor Test. C4 levels are typically low in both hereditary and acquired forms of angioedema, and measuring them alongside C1-INH helps confirm the diagnosis and narrow down the cause.
C1 Esterase Inhibitor Test: Booking, Price, and Results
