Medical Disclaimer: The information provided here is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Do not start, stop, or change any treatment based on this information without consulting your doctor. Always seek personalized medical care to address your specific health concerns and conditions.
Antinuclear Antibody Test
Have you had a blood test showing a high antinuclear antibody (ANA) titer, only to be told it’s “normal” by your healthcare provider? While detectable ANA isn’t always cause for concern, persistently high ANA titers (≥1:320) might indicate underlying immune system issues.
Let’s brainstorm about what a high ANA titer means, why these autoantibodies shouldn’t be in your body, and how they might be forming.
What Are ANAs, and Why Shouldn’t They Be There?
Anti-nuclear antibodies (ANAs) are autoantibodies that mistakenly target components inside your cells’ nuclei, such as DNA, histones (DNA-wrapped ‘spools’), or other nuclear proteins (bottom right, image below).
The formation of autoantibodies is rare because the body is trained to distinguish “self targets”, like your DNA, nuclear proteins, or histones, from “non-self targets” such as viral or bacterial proteins. When antinuclear antibodies are detected at high levels (e.g., titers ≥1:320), it suggests your immune system is reacting to your nuclear material, which is abnormal. This can point to immune dysregulation, a hallmark of many autoimmune and infection-associated chronic conditions (IACCs) listed in the table below.
How Are ANAs Detected?
The ANA test starts by collecting the serum portion of your blood, the plasma, by removing red and white blood cells and clotting factors. Next, the antibody-containing plasma sample is diluted using the following range of dilutions: 1:40, 1:80, 1:160, 1:320, 1:640. Here is what this means.
A 1:40 dilution would be one volume of your blood plasma mixed with 39 equal volumes of a saline buffer, while a 1:640 dilution would have 639 equal volumes of the buffer. Thus, a 1:40 dilution of your plasma will have 16 times more antibodies than a 1:640 dilution of your plasma (640 
40 = 16). This means that detecting anti-nuclear autoantibodies at a 1:640 dilution, which is considered a very high ANA titer, suggests a greater likelihood of autoimmune dysfunction.
A titer of 1:320 or higher is often considered positive; however, 33% of healthy individuals have a 1:40 titer, 10-15% have a 1:80 titer, 5% have a 1:160 titer, and 3% have a 1:320 titer. Lower or negative titers reduce the likelihood of an autoimmune condition.
What Conditions Are Associated With High ANA Titers?
High ANA titers are often observed in autoimmune diseases like systemic lupus erythematosus (SLE, hereafter referred to as Lupus), Sjögren’s Disease, and autoimmune forms of arthritis. Still, they may also occur in conditions like MS, Long COVID, or Lyme disease, but this is less common and less specific, often requiring further investigation to rule out other causes. A high ANA doesn’t always mean you have a classic autoimmune disease. For instance, high ANA titers can be observed following severe COVID-19. Yet, persistently high ANA is a red flag that your immune system is misfiring—something that shouldn’t be dismissed as “normal,” especially when you’re symptomatic.
Why Is Your Immune System ‘Seeing’ Nuclear Antigens?
Nuclear components like DNA and histones stay safely tucked inside your cells’ nuclei, invisible to antibody-producing B cells. So, how might your immune system encounter nuclear antigens? The truth is, there are several ways this nuclear material can be ‘seen’ by your immune system, such as from dying or damaged cells releasing nuclear contents due to chronic inflammation or infections. Another potential driver of ANA production that we would like to focus on is neutrophil NETosis. Here is why.
A neutrophil (yellow) is shown releasing a DNA NET (green) to capture harmful bacteria (purple) that are attacking a red blood cell (orange). Source: Wikimedia Commons, CHDENK
Neutrophil NETosis
Neutrophils, the most abundant immune cells in the human body, are the first responders to pathogens and inflammation. These often overlooked protectors account for 50%-70% of your body’s white blood cells and play a critical role in fighting bacterial and fungal infections. One way neutrophils fight pathogens is by ejecting a net of condensed DNA and histone proteins that traps evading microbes. Like an angler casting a net to catch fish, neutrophils cast a net of DNA to capture and kill pathogens, a process called neutrophil extracellular traps (NETs or NETosis). The image above shows neutrophils casting a net of DNA to capture and kill pathogens. However, excessive NET formation or a defect in NET clearance can prolong immune exposure to nuclear antigens, increasing the likelihood of ANA production. This phenomenon is most thoroughly described in Lupus, where a hallmark of the condition is high ANA titers.
However, Lupus isn’t the only medical condition in which NETosis is triggered. It has been hypothesized as a driver of Long COVID in a subset of patients recovering from severe COVID-19. This theory is admittedly backed by limited data at present; however, research is ongoing to determine whether NETosis directly contributes to ANA production in Long COVID or other infection-associated chronic conditions.
Here is a list of Brain Inflammation Collaborative-focused medical conditions where NETosis has been described to play a role in the pathology of diseases.
| Medical Condition | Notes | Citation(s) |
|---|---|---|
|
Autoimmune Arthritis (Rheumatoid Arthritis, Psoriatic Arthritis, Ankylosing Spondylitis) |
Rheumatoid Arthritis: NETs contribute to synovial inflammation, autoantibody production, and joint damage. Psoriatic Arthritis: NETs in skin and joints amplify inflammation, driven by cytokines like IL-17. Ankylosing Spondylitis: Emerging evidence suggests NETs contribute to spinal inflammation. |
Khandpur, R., et al. (2013). Science Translational Medicine. PMID: 23536012
Li, B., et al. (2022). Frontiers in Immunology. PMID: 35774788
Papagoras, C., et al. (2021). European Journal of Immunology. PMID: 33340091 |
|
Autoimmune Encephalitis |
NETs promote neuroinflammation, particularly in anti-NMDA receptor encephalitis, by breaching the blood-brain barrier and causing neuronal damage. |
Qiao, S., et al. (2022). Frontiers in Immunology. PMID: 36569875 (anti-NMDAR encephalitis) |
|
Crohn’s Disease
|
NETs in inflamed gut tissue amplify inflammatory cytokine production and contribute to tissue damage. |
Liu, Y., et al. (2024). Heliyon, 10(23), e40577. PMID: 39654789 |
|
Long COVID |
NETs are linked to immunothrombosis and persistent systemic inflammation, contributing to symptoms like fatigue and brain fog. |
Shafqat, A., et al. (2023). Frontiers in Immunology, 14, 1254310. PMID: 37828990
Thierry, A. R., et al. (2024). Journal of Medical Virology, PMID: 39189651 |
|
Multiple Sclerosis (MS) |
NETs promote blood-brain barrier disruption and neuroinflammation, with elevated NET markers in serum and cerebrospinal fluid. NETs are associated with the disease severity of MS. |
Tillack K, et al. J Neuroimmunol. (2013). PMID: 23735283
Quan M, et al. Front Immunol. (2025). PMID: 39935468 |
|
Psoriasis |
NETs in psoriatic lesions release pro-inflammatory mediators, amplifying immune responses and epidermal hyperproliferation. |
Zhang, J., et al. (2024). Frontiers in Immunology. PMID: 39148738
Shao, S., et al. (2019). Frontiers in Immunology, 10, 746. PMID: 31024570 |
|
Sjogren’s Disease |
NETs in salivary glands contribute to glandular inflammation and autoantibody production. |
Verstappen, G. M., et al. (2021). Rheumatology, 60(4), 1752–1762. |
The Role of NETosis in Microclot Formation
Long COVID patients have small blood clots that obstruct blood flow in capillary beds. These microclots are associated with numerous Long COVID symptoms, including brain fog and chronic fatigue. Recent data suggest these microclots are difficult for the body to eliminate because they are wrapped in DNA derived from neutrophil NETs. These microclots were also found in other infection-associated chronic conditions, such as ME/CFS.
NETosis in CNS Conditions
In brain diseases, the formation of NETs can make the disease worse by enhancing inflammation. They trigger a part of the innate immune system called the complement system and cause the body to produce pro-inflammatory cytokines, creating a harmful environment that can damage brain tissue, potentially worsening conditions like stroke, autoimmune disorders affecting the brain like MS, and neurodegenerative diseases such as Alzheimer’s disease. However, more research is needed to explore the role NETs play in other chronic inflammatory conditions and in infection-associated chronic conditions (if any), as research in this area is nonexistent.
How NETs are Formed
Neutrophils form NETs via two mechanisms. Lytic NETosis: Stimuli like pathogens or cytokines trigger chromatin decondensation, nuclear membrane breakdown, and cell rupture, releasing DNA, histones, and antimicrobial proteins as NETs. Lytic NETosis leads to neutrophil death (image below).
Non-lytic NETosis: Neutrophils release NETs without dying, rapidly expelling nuclear or mitochondrial DNA through vesicles while maintaining membrane integrity. This is triggered by specific stimuli (e.g., Staphylococcus aureus or immune complexes) and enables neutrophils to survive and function after NET release, contributing to inflammation or pathogen trapping.
What Does This Mean for You?
A high ANA titer suggests your immune system is reacting to nuclear antigens, likely due to chronic inflammation and processes such as NETosis or pro-inflammatory mechanisms of cell death, including pyroptosis, necroptosis, feroptosis, or specific genetic factors. This isn’t “normal” and warrants further investigation, especially if you have symptoms like fatigue, brain fog, joint pain, or neurological issues. Here’s what you can do:
- Advocate for Specificity: Ask for follow-up tests to identify specific autoantibodies (e.g., anti-dsDNA, anti-Ro, or anti-Smith) or markers of inflammation (e.g., C-reactive protein, complement levels) to clarify the cause.
- Contextualize Symptoms: Share your full symptom history and diagnoses with a specialist (e.g., rheumatologist or neuroimmunologist) familiar with autoimmunity and other chronic inflammatory diseases, as these conditions often require a nuanced approach.
- Explore Triggers: NETosis can be fueled by infections, stress, or environmental factors. Addressing underlying infections (e.g., Lyme, viral persistence) or reducing inflammation (e.g., through diet or targeted therapies) may help.
The Bottom Line
A high ANA titer in chronic neuroimmune or inflammatory conditions is a signal that your immune system is under stress. While it may not always mean a classic autoimmune disease, it’s not something to brush off. Your symptoms and ANA results deserve to be taken seriously, as they may reflect a deeper immune imbalance tied to your condition.
Keep advocating for answers, and work with a healthcare provider who understands the complexities of IACCs to understand if your ANA titers are hinting at potential immune dysregulation. Consider consulting a rheumatologist, neurologist, or other specialist, depending on your symptoms, as different conditions may require input from multiple fields.
Written By
Matthew Menendez, Ph.D.
Director of Science Communication, Brain Inflammation Collaborative
Dr. Menendez has a passion for empowering patients navigating complex chronic diseases. Through innovative educational strategies, he bridges the gap between cutting-edge research and real-world understanding, helping individuals advocate for better care, access timely treatments, and reclaim their quality of life.
