Voltage-gated calcium channel (VGCC) antibody test
Quick answer: This blood test looks for antibodies against voltage-gated calcium channels on nerve endings. Doctors usually order it when they suspect Lambert-Eaton myasthenic syndrome, which causes muscle weakness and can be linked to lung cancer.
- SampleBlood
- TakesAbout 5 minutes
- Before the testNo special preparation is usually needed.
How the test is done
- 1You sit and your arm is straightened
- 2A vein is cleaned and a needle inserted
- 3Blood is collected into a tube
- 4The lab measures antibodies to P/Q-type calcium channels
What your results can mean
Reading your report
A positive result does not by itself confirm a disease, because some healthy people test positive; your doctor reads it with your symptoms and other tests.
If the result is outside the usual range
A positive result can point to Lambert-Eaton myasthenic syndrome, which causes weakness in the hips and shoulders. It can be linked with small-cell lung cancer, so doctors may arrange a chest scan.
Who usually has this test
People with weakness of the thighs and upper arms, dry mouth, or reduced reflexes, especially smokers or former smokers.
Risks and aftercare
The blood draw itself needs no aftercare; tell staff if your weakness makes it hard to sit up or walk.
Names and options
Also called: VGCC, P/Q-type calcium channel antibody, LEMS antibody
Listed by the hospital as
- VOLTAGE GATED CALCIUM CHANNEL ANTIBODY (VGCC), SERUM
Questions about this test
How is Lambert-Eaton syndrome different from myasthenia gravis?
Lambert-Eaton usually weakens the hips and shoulders first, and strength may briefly improve with exercise. Myasthenia more often starts with eye and face muscles.
Does a positive VGCC antibody mean I have lung cancer?
Not always. About half of people with Lambert-Eaton syndrome have no cancer. Doctors usually arrange scans to check carefully.
Can the test be repeated over time?
It may be repeated if symptoms change. Doctors may also repeat cancer screening scans for a few years after the diagnosis.
Related tests
Tamara Hospital & IVF Centre, Rajajinagar
34/3, 10th Cross Road, opp. Vardhaka Sardar Patel School, 1st N Block, 2nd Stage, Rajajinagar, Bengaluru 560010
The hospital is open 24 hours. Call before you come to check the timing for your scan or sample collection.
Get directions ↗IVF Pulse fertility care at Tamara Hospital →
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This page explains each test in general terms so you know what to expect. It is not medical advice: your doctor decides which tests you need and what your results mean. Reference ranges differ between laboratories. Updated 4 November 2026.