What's this test for?

This test is ideal if you're taking infliximab (Remicade or a biosimilar) for Crohn's disease, ulcerative colitis, rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, or psoriasis and your symptoms aren't fully under control. It's also useful if your condition was well managed but symptoms are starting to come back. Checking your drug level and antibody status can help explain why the medication may not be working as well as expected.

What's included in this test?

This test measures two things together: how much active infliximab is in your blood, and whether your body has developed antibodies against it. Looking at both values together gives a clearer picture than either one alone, since low drug levels can happen either because your body clears the drug quickly or because antibodies are breaking it down. Understanding which situation applies to you helps guide what change might actually help.

What happens after I get my results?

Your results will show up in your account with both your infliximab drug level and antibody level, along with an explanation of what each range means. If your drug level is low without antibodies, next steps often involve adjusting your dose or infusion schedule going forward. If antibodies are high, this usually signals your body is fighting off the drug, which is useful information to act on. You can download a standard lab report from your account, and track how your levels change over time using the trends feature if you retest later.

How can I naturally support my response to infliximab?

While diet and lifestyle can't replace your medication, some habits may support better outcomes alongside it. Reducing inflammatory foods, not smoking, and managing stress have all been linked to better disease control in Crohn's and colitis. Staying consistent with your infusion schedule matters too, since missed or delayed doses can encourage antibody formation. Talk through any supplement plans carefully since some can interact with immune-modulating therapy.

When will I get my results?

Results are typically ready within about 7 days of your blood draw. You'll get a notification once they're posted to your account so you can log in and review them right away. If anything looks like it needs urgent attention, don't wait for a routine check-in — seek medical care promptly.

Who should consider this test?

Anyone currently on infliximab therapy whose symptoms are flaring despite treatment, or who wants to confirm the medication is working before continuing long-term, is a good candidate. It's also worth considering if you're being evaluated for a dose change or a switch to a different biologic. People who've had infusion reactions may also want to check antibody levels.

What symptoms indicate I may need this test?

Returning or worsening symptoms of your underlying condition — like abdominal pain, diarrhea, joint pain, or skin flare-ups — despite staying on infliximab are the main signal. Infusion reactions, such as fever, rash, or discomfort during treatment, can also point to antibody formation. If your symptoms were controlled and are now creeping back, that's a common reason people check their levels.

What does a low infliximab level mean?

A low drug level means there isn't much active medication circulating in your blood, which can allow your original symptoms to return. This can happen because your body clears the drug faster than expected, or because antibodies are breaking it down. If antibodies are also low, increasing the dose or shortening the interval between infusions is often considered. If antibodies are high instead, drug optimization is less likely to help and a different biologic may be more effective.

What causes high antibody levels against infliximab?

Antibodies form when your immune system recognizes infliximab as foreign and starts attacking it, which is more likely with inconsistent dosing, longer gaps between infusions, or stopping and restarting treatment. Some people are simply more prone to developing antibodies regardless of dosing pattern. Combining infliximab with another immune-modulating medication is sometimes used specifically to reduce this risk.

How often should I retest?

Retesting is usually most useful when your symptoms change or before a planned adjustment to your treatment plan, rather than on a fixed schedule. Some people check levels a few months after starting infliximab to confirm it's working, then again anytime symptoms return. Using the trends feature in your account can help you and your care team spot patterns over multiple infusions.

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.

Infliximab Level & Antibody Test - Biologic Monitoring

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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