Sm/RNP Antibody
An antinuclear antibody that helps sort out lupus, mixed connective tissue disease, and overlap syndromes.
Consider this test if:
- A positive ANA needs further workup to pin down the diagnosis
- Joint pain, facial rash, persistent fatigue, or photosensitivity suggest lupus
- Raynaud's, swollen fingers, or muscle weakness raise the question of mixed connective tissue disease
- Tracking an established autoimmune diagnosis with your rheumatologist
- HSA/FSA eligible
- Results delivered to your dashboard · Reviewed by a real clinician
- Drawn at a CLIA/CAP-accredited lab near you ·
Pre-test considerations
No fasting required and no special timing. A standard blood draw is all that is needed.
Video consult with your Care Team
A 1:1 call to discuss your health.
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What this test is for
Sm/RNP measures antibodies against two extractable nuclear antigens, Smith (Sm) and U1-ribonucleoprotein (RNP), that the immune system mistakenly targets in certain autoimmune diseases. Anti-Sm is highly specific for systemic lupus erythematosus, while high anti-RNP is the defining feature of mixed connective tissue disease, which combines features of lupus, scleroderma, and polymyositis. It is typically ordered after a positive ANA to narrow the diagnosis when symptoms like joint pain, persistent fatigue, facial rash, Raynaud's, muscle weakness, or unexplained inflammation point toward connective tissue disease. A positive result supports a diagnosis but is interpreted alongside symptoms, exam findings, and other autoantibodies, since antibody patterns overlap across these conditions. A negative result is most useful for helping rule these specific diagnoses out when an ANA workup is underway.
What to expect
- 1 Book instantly
Click, book, done. Choose a convenient lab location near you. Transparent, up-front pricing.
- 2 Quick lab visit
Testing to fit your busy schedule, usually 15 minutes or less. Walk-in and appointments available.
- 3 Fast, dashboard-delivered results
Your results post straight to your dashboard as soon as the lab completes them.
- 4 Expert guidance
Included with Mito membership. A clinician reviews your results and your personalized action plan follows, with clear next steps.
Everything your health needs,
in one membership
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Every test at our cost
Members pay our cost on every test, with lab fees passed straight through. The full receipt is itemized, never padded.
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Continuous tracking, all in one place
Upload past labs and watch your trends over time. Every marker and visit lives in one longitudinal record, so all your care stays together.
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Year-round clinician support
Text anytime and get clinician-reviewed answers. When you want to go deeper, 1:1 consultations are available at affordable rates.
All for $9/month
Order any test or consult without joining. For $9/month, members unlock member prices, trend tracking, and year-round clinician guidance.
Mito Membership
$9 /mo
cancel anytime
Without membership
$0
pay as you go
At-cost pricing on labs, scans, and more
Priority turnaround on your results
On-demand clinician consults when you need guidance
Personalized action plans across supplements, exercise, nutrition, and sleep
AI health coaching to help you act on your results
Year-round medical support, with in-chat clinician escalation
All your health records in one personal vault, with trends and biological age tracking
Early access to new diagnostics and product releases
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Frequently asked questions
View all FAQsHow does pricing work?
Every test shows the member price next to the standard non-member price, so you can see what membership saves you. The member price is our cost — covering the lab and what it takes to run the service — never a profit on the test itself; Mito makes its money on the $9 membership, not on marking up your tests. Membership is $9/mo, and you still pay the lab’s order fee. Prices are itemized before you pay, with no hidden fees.
Where do I get tested?
Choose a partner lab (Quest, Labcorp, or BioReference) at checkout. If your cart spans multiple tests, we consolidate the whole order onto a single lab so you only make one visit.
Is this eligible for HSA/FSA?
Yes. This test is HSA/FSA eligible, and you can pay with your HSA/FSA card at checkout.
When will I get my results?
Your results post to your dashboard once your lab completes them, then a clinician reviews them and your full analysis and personalized action plan (with clear next steps) follow. Turnaround varies by test: specialty assays and at-home kits take longer, and each test shows its expected turnaround before you buy.
Do I need a doctor’s order?
No. Mito provides the lab order for you, so you can book and get tested without a separate doctor visit.
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