What's this test for?

This test is ideal if you're experiencing frequent infections that don't respond well to treatment, unexplained swelling, or autoimmune symptoms like joint pain and inflammation. It helps identify problems with your immune system's complement proteins, which are critical for fighting bacteria and viruses. Many people use this test when they have recurring infections, suspected immune deficiencies, or autoimmune conditions that need diagnosis or monitoring.

What happens after I get my results?

You'll receive detailed doctor notes in simple language explaining what your complement levels mean for your immune function and infection-fighting ability. These notes include personalized recommendations like dietary changes, supplement suggestions, or whether you should consult with an immunologist or rheumatologist. You'll also get the standard lab report and can track your complement levels over time using our trends feature to monitor your immune system health and treatment effectiveness.

What's included in this test?

This panel measures C3, C4, and CH50 (total complement activity). This panel measures C3 and C4 complement proteins, which are essential parts of your immune system that help destroy harmful bacteria and viruses. It also includes CH50, which measures the overall activity of your complement system to see if all the pieces are working together properly. Together, these measurements help identify immune deficiencies, autoimmune conditions like lupus, and explain why you might be getting frequent or severe infections.

How should I prepare for this test?

Overnight fasting is preferred for this test, which means avoiding food for 8-12 hours before your blood draw. You can drink water during this time. Try to schedule your appointment for the morning if possible, and take any regular medications unless your doctor advises otherwise. Fasting helps ensure the most accurate measurement of your complement proteins.

Who should consider this test?

This test is important for people with recurrent infections like pneumonia, meningitis, or sinus infections that keep coming back. It's also valuable for those diagnosed with or suspected of having autoimmune diseases like lupus or rheumatoid arthritis, anyone with unexplained swelling or inflammation, and people with a family history of immune deficiencies. Your doctor may also recommend it if you're being monitored for kidney disease or certain chronic conditions.

What symptoms indicate I may need this test?

Common symptoms include getting sick more often than others around you, infections that are unusually severe or take a long time to clear up, and frequent bacterial infections affecting your lungs, ears, or sinuses. You might also experience persistent joint pain and swelling, unexplained rashes, extreme fatigue, or recurrent fever. If you have kidney problems, unexplained protein in your urine, or a family history of immune disorders, these could also indicate the need for testing.

How can I naturally support my immune system?

While complement deficiencies often require medical management, you can support overall immune health by eating a nutrient-rich diet with plenty of fruits, vegetables, lean proteins, and foods high in vitamins C and D. Getting 7-8 hours of quality sleep, managing stress through meditation or relaxation techniques, and staying physically active all help maintain immune function. Avoiding smoking, limiting alcohol, and staying up to date with vaccinations are also important for protecting yourself from infections.

What is the complement system and why does it matter?

The complement system is a group of proteins in your blood that work together as part of your immune system's first line of defense against infections. Think of it as a team of soldiers that mark invading bacteria and viruses for destruction, punch holes in their membranes to kill them, and call in other immune cells for backup. When your complement system isn't working properly, you become more vulnerable to infections and may develop autoimmune problems where your body mistakenly attacks itself.

What does low C3 or C4 mean?

Low levels of C3 or C4 can indicate that your complement proteins are being used up faster than they're being made, which often happens with active autoimmune diseases like lupus or conditions where your immune system is constantly fighting. It can also mean your body isn't producing enough complement proteins due to genetic deficiencies or liver disease. Low levels make you more susceptible to bacterial infections and may require close monitoring and treatment from a specialist.

How often should I retest my complement levels?

If you've been diagnosed with an autoimmune disease or complement deficiency, your doctor will typically retest every 3-6 months or whenever you experience a flare-up of symptoms or new infections. If you're starting treatment for an autoimmune condition, more frequent testing every 6-8 weeks may be needed initially to monitor how well the treatment is working. Once your condition is stable, annual testing may be sufficient for ongoing 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! 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.

Immune System Test - Frequent Infections & Immunity

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

[email protected]

Blood Test for Frequent Infections and Immune System Health

Complement Component C3, C4, CH50

90 day happiness guarantee

Prescription & fees included

Easy to understand results

Fast & convenient

90 day happiness guarantee

Prescription & fees included

Easy to understand results

Fast & convenient

What's this test for?

How should I prepare for this test?

What's included in this test?

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Blood Test for Frequent Infections and Immune System Health

90 day happiness guarantee

Prescription & fees included

Easy to understand results

Fast & convenient

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