What's this test for?

This test is ideal if you're immunosuppressed, such as from advanced HIV/AIDS, an organ transplant, or certain autoimmune drug treatments, and you or a provider are concerned about a serious brain infection called PML. It looks for active JC virus in your blood, which can signal a risk that isn't detected by antibody testing since most healthy people already carry JC virus antibodies without ever getting sick. It's typically used to help understand unexplained neurologic symptoms in people with weakened immune systems.

What's included in this test?

This test uses a highly sensitive method called real-time PCR to look directly for genetic material from the JC polyoma virus in your blood. Unlike antibody tests, which just show past exposure and aren't useful here since most adults carry JC virus antibodies, this DNA test detects whether the virus is actively present, which is what matters for assessing risk in immunocompromised people.

What happens after I get my results?

Your results will show up in your account with a clear explanation of what a positive or negative finding means for JC virus DNA. If your result is positive, especially alongside neurologic symptoms, it's important to seek medical care right away since this can point to a serious condition needing urgent evaluation. You can download the official lab report anytime from your account, and if you're retested in the future, the trends feature lets you compare results side by side over time.

Who should consider this test?

People with significantly weakened immune systems, such as those with advanced HIV/AIDS, transplant recipients, or people on certain immune-suppressing medications, are the main candidates for this test. It's especially relevant if you're experiencing new neurologic symptoms like confusion, vision changes, weakness, or coordination problems. Healthy individuals without immune suppression generally don't need this test since JC virus is extremely common and usually harmless.

What symptoms indicate I may need this test?

Symptoms like sudden confusion, memory problems, vision loss, weakness on one side of the body, or trouble with coordination and speech can be warning signs, particularly if you're immunosuppressed. These symptoms can point to PML, a rare but serious brain condition linked to active JC virus. If you notice these symptoms, treat them as urgent and seek medical care right away rather than waiting on test results alone.

What does a positive result mean?

A positive result means JC virus DNA was detected in your blood, which in someone with a weakened immune system can be a warning sign for PML risk. It doesn't automatically mean you have PML, but combined with symptoms and your immune status, it's a serious finding that needs prompt medical attention. Retesting or additional evaluation is often needed to fully understand what a positive result means for you.

What does a negative result mean?

A negative result means no JC virus DNA was found in your blood sample at the time of testing, which is reassuring but doesn't rule out infection entirely, especially if virus levels are very low. If you're still having neurologic symptoms despite a negative result, it's worth seeking medical care for further evaluation rather than assuming the virus is not involved. Retesting later can help if your immune status or symptoms change.

How often should I retest?

Retesting frequency really depends on your immune status and whether you're being monitored for ongoing risk, such as during certain immune-suppressing treatments. Some people are tested periodically while on higher-risk medications, while others are only tested if new symptoms appear. Using the trends feature in your account can help you and any care team track changes in results over time.

What should I do if my results are abnormal?

If your result is positive, especially with any neurologic symptoms like confusion, vision changes, or weakness, treat this as urgent and seek medical care immediately. Bring a copy of your downloadable lab report so the situation can be evaluated quickly and thoroughly. Don't wait to see if symptoms improve on their own, since early evaluation matters for serious brain conditions like PML.

What is JC virus and why does it matter?

JC virus is an extremely common virus that most people pick up during childhood or young adulthood without ever knowing it, since it usually stays inactive and causes no problems. It matters because in people with severely weakened immune systems, the virus can reactivate and cause a rare but serious brain disease called PML. This is why testing focuses on immunosuppressed individuals rather than the general population.

Getting your blood test with us is easy, private & backed by the power of science.Long story short: In the test options, use the filters or search box to narrow your choices and find the test you want. If you need a hand navigating through options, text our super friendly support team at 754-799-7833, and we'll provide tailored suggestions to help you find the ideal test. Once your order is placed, we’ll create your doctor’s lab order remotely, without any need for you to make a trip to a doctor in person or to talk to the doctor. Expect to receive your doctor’s lab order right in your inbox. It will also be in your patient portal if you need to find it later. We’ll also include instructions regarding fasting and other requirements for your test. Your patient portal will be auto-created hassle-free during checkout. If this is your first time ordering, you'll be prompted to create a password for instant login access to your patient portal. It's a quick way to conveniently access your orders and results whenever you want. When you’re ready, visit one of our 4,000 locations. Just bring your ID – no printing or faxing of your lab order is needed, as your order and details will already be in the lab system. Note that most lab locations don’t accept walk-ins, so it’s best to book an appointment in advance. Don’t worry – we’ll provide detailed instructions along the way. You’ll get your results via email & SMS and dive into understanding your body better. Yup, that easy! If you have any questions, please text us at 754-799-7833 or email support@privatemdlabs.com and we'll gladly help you.

How do I know which test to get?

In the test options, find the test you want. If you’re not sure which test to get, we can lend a hand in finding the right option. Just text or call us at 754-799-7833, email us at support@privatemdlabs.com, and we'll gladly help you. We've got your back and reply quickly.

When will my lab results be available?

Most test results will be available within 1–3 business days. Once they're ready, we'll send an email and text message to let you know. After your blood draw, just hang tight and don't worry – we'll keep you updated and in the loop! If you have any further questions, please text us at 754-799-7833 or email support@privatemdlabs.com, and we'll gladly help you.

Is it possible to make changes to my lab order if I made a mistake with the name, date of birth, or any other details?

Absolutely! We totally understand that errors can happen. No worries, we're here to help you. Just reach out to us via text at 754-799-7833 or shoot us an email at support@privatemdlabs.com. Remember to include your order number and let us know the correct information you’d like to update. Our awesome team will jump right in and make sure everything is sorted out and accurate for you. There are no changes necessary if your address is wrong on the requisition though. We don’t mail anything out. Our lab requires an address to be listed to generate an order.

Do you accept health insurance?

Only HSA & FSA is accepted. Our services are strictly self-pay and cannot be submitted to your health insurance provider except for Health Savings Accounts or Flexible Savings Accounts. This policy applies to all insurance companies, including federal health insurance programs like Medicare. If you have any questions, please text us at 754-799-7833 or email support@privatemdlabs.com.

Can I cancel my order?

Yes. We get it – sometimes your needs change. As long as your samples haven’t been collected yet, we’re happy to help you cancel your order. If you have any further questions, please text us at 754-799-7833 or email support@privatemdlabs.com. You can read more about our cancellation policy here.

How can I find a lab location near me?

During the ordering process, you’ll be able to select a specific lab near you, with no strings attached! You can switch it up later easily and visit any of our authorized locations as long as it’s the same lab company you selected your test for (Quest Diagnostics or Labcorp). Before you proceed with your order, feel free to browse through all our lab locations here. This will give you the peace of mind of knowing that there's a lab nearby your home, office or your favorite gym. If you have any questions, please text us at 754-799-7833 or email support@privatemdlabs.com and we'll gladly help you.

JC Virus DNA Test - PML Risk Screening

Getting your blood test with us is easy, private & backed by the power of science.

Long story short:

In the test options, use the filters or search box to narrow your choices and find the test you want.
If you need a hand navigating through options, text our super friendly support team at 754-799-7833, and we'll provide tailored suggestions to help you find the ideal test.
Once your order is placed, we’ll create your doctor’s lab order remotely, without any need for you to make a trip to a doctor in person or to talk to the doctor. Expect to receive your doctor’s lab order right in your inbox. It will also be in your patient portal if you need to find it later. We’ll also include instructions regarding fasting and other requirements for your test. Your patient portal will be auto-created hassle-free during checkout.
If this is your first time ordering, you'll be prompted to create a password for instant login access to your patient portal. It's a quick way to conveniently access your orders and results whenever you want.
When you’re ready, visit one of our 4,000 locations. Just bring your ID – no printing or faxing of your lab order is needed, as your order and details will already be in the lab system.
Note that most lab locations don’t accept walk-ins, so it’s best to book an appointment in advance. Don’t worry – we’ll provide detailed instructions along the way.
You’ll get your results via email & SMS and dive into understanding your body better. Yup, that easy!

754-799-7833

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