What's this test for?

This test is ideal if you're experiencing unexplained swelling, foamy urine, or have been told your kidney function looks unusual. It's also useful if you've had recurring infections or an autoimmune condition and your prior lab work showed low complement levels. This test looks for an antibody that can overactivate part of your immune system and affect your kidneys.

What's included in this test?

This test measures a single, highly specific marker rather than a broad panel. It matters because this particular antibody, when present, can point to an immune process that's affecting how your kidneys filter waste, which is why it's often used when other kidney findings are unclear.

What happens after I get my results?

Your results will show up in your account along with the normal range for this marker so you can see exactly where you stand. If your result comes back positive or unusual, a common next step is retesting to confirm the finding and watching for related symptoms like swelling or changes in urination, and seeking care quickly if you notice sudden or severe symptoms. You can download a standard lab report straight from your account at any time. If you test again in the future, the trends feature lets you compare results side by side over time.

How can I naturally support kidney and immune health?

Staying well hydrated, cutting back on excess salt and processed foods, and keeping blood pressure in a healthy range all help take stress off your kidneys. Regular moderate exercise and getting enough sleep support a balanced immune system. Avoiding unnecessary use of ibuprofen-type pain relievers can also protect kidney function over time.

When will I get my results?

Results are typically ready within about 7 days of your blood draw. You'll get a notification as soon as they're posted to your account so you don't need to check repeatedly. Because this is a specialized test, it can occasionally take a bit longer than routine bloodwork.

Who should consider this test?

This test is a good fit for people who have unexplained kidney findings, recurring low complement levels on prior labs, or symptoms like swelling and foamy urine. It's also considered when someone has an autoimmune condition and their care team wants a clearer picture of what's driving kidney changes. People with a family history of certain kidney disorders may also consider it.

What symptoms indicate I may need this test?

Common signs include swelling in the legs, ankles, or around the eyes, foamy or bubbly urine, unexplained fatigue, and unusual results on a basic metabolism or kidney panel. Recurrent infections combined with low complement levels on prior bloodwork can also be a signal. If you notice sudden swelling or a big drop in how much you're urinating, treat that as urgent.

What does a positive result mean?

A positive result means the antibody was detected, which suggests your immune system may be overactivating a pathway called the complement system. This can sometimes affect how well your kidneys filter blood, so it's often followed up with additional kidney function tests. It doesn't diagnose a specific disease on its own, but it gives useful information for next steps.

How often should I retest?

If your first result is negative and you have no ongoing symptoms, retesting isn't usually necessary unless new symptoms appear. If your result is positive or borderline, retesting every few months alongside basic kidney function tests can help you track any changes. Always factor in how you're feeling, not just the numbers, when deciding on timing.

What should I do if my results are abnormal?

Start by reviewing the explanation in your lab report so you understand what the specific value means. Keep an eye on symptoms like swelling, changes in urination, or fatigue, and consider a follow-up kidney panel to get a fuller picture. If you experience severe swelling, very low urine output, or other serious symptoms, seek medical care right away.

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.

C3 Nephritic Factor Test - Kidney & Immune Check

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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