GAD 65 Antibody Test: Booking, Price, and Results
About GAD 65 Antibody Test: Booking, Price, and Results
| Field | Value |
|---|---|
| Also Known As | Anti-GAD65 Antibody, Glutamic Acid Decarboxylase-65 Antibody, GAD65 Ab Assay, GAD-65 IgG Antibodies, Anti-GAD Antibodies, Pancreatic Islet Cell Antibody |
| Sample Type | Venous blood (serum) |
| Fasting Required | No fasting required |
| Report Time | 24 hours to 7 business days |
| Recommended For | All ages and genders; commonly ordered for those with suspected type 1 diabetes, LADA, or neurological symptoms |
| Price | Starting at ₹1,450 |
What Is a GAD 65 Antibody Test?
The GAD 65 antibody test measures the level of autoantibodies directed against the GAD65 enzyme, a protein involved in producing a key chemical messenger in the nervous system. These anti-GAD antibodies are an important marker for autoimmune activity linked to type 1 diabetes and certain neurological conditions. A small blood sample drawn from a vein in your arm is all that is needed. Doctors may also refer to this test as the GAD65 Ab assay or the Glutamic Acid Decarboxylase (GAD) antibodies test.
What Does a GAD 65 Antibody Test Measure?
The test looks for two things in your blood sample. Here is what each component represents:
| Component | What It Is |
|---|---|
| GAD65 Enzyme | A protein found in nerve cells that helps produce GABA, a chemical that regulates nerve communication |
| GAD65 Antibodies (Anti-GAD65 IgG) | Proteins mistakenly made by the immune system that attack the body's own GAD65 enzyme; a key marker for autoimmune diabetes and related neurological conditions |
Why Is a GAD 65 Antibody Test Done?
A doctor may order this test for a range of reasons, from evaluating unusual diabetes presentations to investigating neurological symptoms. Below are the most common reasons this test is requested.
Common Symptoms That May Require This Test
A doctor may recommend the GAD 65 antibody test if you have any of the following:
- Unexplained fatigue or persistent tiredness
- Unintentional weight loss
- Excessive thirst or frequent urination
- Blurred vision
- Muscle stiffness or spasms
- Difficulty walking or poor coordination
- Symptoms of brain or nerve dysfunction
Conditions This Test Can Help Detect
This test can assist in identifying or ruling out several conditions, including:
- Type 1 (autoimmune, insulin-dependent) diabetes mellitus
- Latent autoimmune diabetes in adults (LADA), a slowly progressive form of autoimmune diabetes that can be mistaken for type 2 diabetes
- Stiff person syndrome, a neurological condition causing severe muscle rigidity
- Autoimmune encephalitis (brain inflammation caused by the immune system)
- Autoimmune ataxia (loss of muscle coordination due to immune activity)
- Autoimmune epilepsy and autoimmune myelopathy (spinal cord disease)
- Predisposition to related autoimmune conditions such as thyroid disease, pernicious anaemia, and Addison's disease
How to Prepare and What to Expect
Preparation for this test is minimal, but a few steps will help ensure your sample gives accurate results.
Do You Need to Fast?
No, fasting is not required. You can have your blood drawn at any time of the day, regardless of when you last ate or drank. However, if additional tests have been ordered alongside this one, some of those may require fasting. In such cases, always check with your doctor.
Practical Tips Before Your Test
A few simple precautions before your appointment will help ensure a valid result:
- Stop taking biotin (vitamin B7) supplements at least 72 hours before sample collection, as high-dose biotin can interfere with the test
- Inform your doctor about all medications and supplements you are currently taking
- Wear a short-sleeved top or clothing with sleeves that can be rolled up easily
- Let your sample collector know if you have had any radioisotope therapy or diagnostic imaging recently
Step-by-Step Procedure
Here is what happens during a typical blood collection for this test:
- A trained phlebotomist cleans the inner elbow area with an antiseptic solution.
- A tourniquet is wrapped around your upper arm to make the vein easier to locate.
- Blood is drawn through a sterile needle into a serum separator tube.
- The needle is removed, and a small dressing is applied to the site.
- The sample is refrigerated to preserve its integrity while awaiting dispatch.
- The sample is sent to the laboratory for analysis.
Factors That Can Affect Accuracy
Certain factors may affect the reliability of your result:
- High-dose biotin supplementation before sample collection
- Recent administration of radioisotopes for therapy or imaging
- Gross haemolysis (red blood cell breakdown), high blood fat content (lipaemia), or elevated bilirubin (jaundice) in the sample
- Improper sample storage or handling during transport
Understanding Your GAD 65 Antibody Test Results
Your results should always be reviewed with your doctor, who will consider them alongside your symptoms, medical history, and other tests. The table below shows the general reference ranges used for this test.
| Parameter | Normal (Negative) | Unit |
|---|---|---|
| GAD65 Antibody | Less than 5.0 | IU/mL |
| GAD65 Antibody | Less than 0.03 | nmol/L |
A result below the cut-off suggests no current autoimmune activity against GAD65-producing cells. Low-to-detectable levels (0.03 to 19.9 nmol/L) are found in approximately 80% of patients with type 1 diabetes but in fewer than 5% of those with type 2 diabetes. High levels at or above 20.0 nmol/L are associated with stiff person syndrome and related neurological disorders.
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
Some situations can affect how your results should be interpreted:
- Older adults: Anti-GAD antibodies are present in approximately 8% of healthy individuals over age 50, usually at low levels. This may reflect a predisposition to autoimmune disease rather than an existing condition, and your doctor will assess this in context.
- Biotin supplementation and radioisotope exposure: Both can interfere with the assay and potentially produce inaccurate results. Always disclose supplement use and any recent imaging or therapy before your test.
How to Maintain Healthy Levels
Because elevated GAD-65 IgG antibodies reflect an underlying autoimmune process, there are no direct lifestyle steps to reduce antibody levels. However, these general habits support overall health:
- Eat a balanced diet with a good mix of whole foods, vegetables, and lean protein to support metabolic health
- Take part in regular physical activity suited to your current fitness level
- Work closely with your doctor to monitor blood glucose and pancreatic function if your result is positive
Lupin Diagnostics GAD 65 Antibody Test Price and Home Collection
The GAD 65 antibody test is available at Lupin Diagnostics starting at approximately ₹1,450, with home sample collection available across cities. The approximate prices are listed below:
| City | Approximate Price (₹) |
|---|---|
| Pune | ₹2,900 |
| Mumbai | ₹2,900 |
| Bengaluru | ₹2,900 |
| Hyderabad | ₹2,900 |
| Chennai | ₹2,900 |
| Kolkata | ₹2,900 |
| Ahmednagar | ₹2,900 |
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
Lupin Diagnostics offers home blood collection for the GAD 65 antibody test in multiple cities across India, performed by trained phlebotomists. All samples are processed in NABL-accredited laboratories to ensure reliable results. Once ready, your digital report is accessible via email or WhatsApp.
Frequently Asked Questions
The GAD 65 antibody test is primarily used to distinguish autoimmune (type 1) diabetes from type 2 diabetes when the clinical picture is unclear. It also helps diagnose neurological conditions such as stiff person syndrome and autoimmune encephalitis. Your doctor will recommend it based on your symptoms and history.
No fasting is needed. You can eat and drink as normal before your sample is collected. There are no specific dietary restrictions for this test.
Yes. Anti-GAD antibodies can be detectable in the blood before blood glucose levels become abnormal. Their presence is considered a strong predictive marker for the eventual development of autoimmune diabetes, which is why early testing can be valuable in high-risk individuals.
LADA stands for latent autoimmune diabetes in adults. It is a slowly progressive form of autoimmune diabetes that shares features with both type 1 and type 2 diabetes and is frequently misdiagnosed. The GAD65 Ab assay helps identify LADA in adults who appear to have type 2 diabetes but do not respond as expected to standard treatments.
Levels at or above 20.0 nmol/L are strongly associated with stiff person syndrome, with a positive rate of about 93% in classic cases. High levels may also indicate related neurological conditions, such as cerebellar ataxia and limbic encephalitis. Your doctor will correlate these findings with your clinical symptoms.
Yes. If you are taking biotin (also called vitamin B7, vitamin H, or coenzyme R), stop at least 72 hours before your blood draw. High doses of biotin can interfere with the assay and produce inaccurate results. Always inform your doctor about any supplements you are taking.
Not entirely. Around 70 to 80% of patients with type 1 diabetes have detectable glutamic acid decarboxylase (GAD) antibodies, meaning a small proportion will test negative. If your doctor still suspects autoimmune diabetes, additional autoantibody tests may be recommended to complete the picture.
GAD 65 Antibody Test: Booking, Price, and Results
