Mycobacterium tuberculosis Antibody Screening (Serum/Plasma)

What This Test Measures

The test looks for specific antibodies (proteins produced by your immune system) that your body creates in response to *Mycobacterium tuberculosis*. These antibodies can appear months or years after exposure, even if you never developed active TB. The presence of these antibodies suggests your immune system has encountered the bacterium, but it does not confirm current infection or disease.

Why It Might Be Ordered

Your healthcare provider may order this test if you have risk factors for TB, such as living or traveling in areas with higher TB rates, having weakened immunity (e.g., from HIV, certain medications, or chronic illnesses), or if you’ve been exposed to someone with active TB. It may also be used as part of screening for healthcare workers or individuals entering high-risk settings.

What to Expect Before the Test

No special preparation is needed. You’ll provide a blood sample, typically drawn from your arm in a clinic or lab. The process takes a few minutes, and you can resume normal activities afterward. If you’re on blood-thinning medications, let your provider know before the test.

What to Expect After the Test

You’ll receive your results from your healthcare provider. If the test is positive, further testing (like a TB skin test or culture) will be needed to determine if you have active TB or just past exposure. If negative, it means your body likely hasn’t encountered *Mycobacterium tuberculosis* recently.