This is the biggest rookie mistake. If you quit gluten before testing, your body will hide the evidence. Your test results will be as useless as a chocolate teapot.
Keep eating that sourdough. Devour the pasta. Gluten is your friend for now—your accomplice in crime-solving. You need the gluten to be in your system for the antibodies to show up.
Think of it like planting a flag. The gluten is the flag, and your immune system is the angry guard. You need the guard to be visible on the test.