Isn’t that the one that means lupus?
The answer is yes and no.
If you’re a patient who has long been tumbling down the rheumatology rabbit hole, you are likely already familiar the above answer. Rheumatology is heavy in the shades of grey.
For the latest of you, prime yourself for the grey!
ANAs are antibodies created by your immune system generally regarded as antibodies against intracellular components.
The problem is they are terribly sensitive, but not specific. There’s a saying I once heard, that may come off as a bit too much hyperbole for some, but “you can stub your toe and have a positive ANA.”
Meaning it does not always mean autoimmune disease. I’ve had patient’s told “you have x, y, z,” based on antibodies alone, and it’s almost always dummies in my field (naturopathy/functional medicine).
One of my favorite types of consults is the +ANA consult, because I get to put on my detective hat and learn about the man or woman before me in intimate detail and see if the ANA makes sense.
Beyond positive/negative, you should understand what titer means.
The titer is the degree of positivity, listed as 1:40, 1:80, 1:160… 1:640, 1:1280 and so on.
1:40 lowest positive, 1:1280 high positive. We consider 1:640 a border point.
Below 1:640 that we have less confidence that it is meaningful and more benign. Higher than that we have more confidence that something is wrong. It doesn’t necessarily mean you’re sick and going to die soon, but something is more likely wrong and we need to dig deeper.
Some providers write things off entirely if the ANA is low positive <1:640. And that is wrong. You can have a low +ANA or even absent ANA with raging autoimmune disease. Same goes for inflammatory markers, which we’ll talk about later.
Beyond the above there is the pattern…
Lots of speckled, Nuclear dots, Peripheral, Rainbow, Saturday Night, Wintertime, Post Grad (I made the last few up) and so on…
I’m of the opinion who cares for pattern unless it’s centromere or nucleolar. The other patterns are not very specific.
Coming back to the “specificity” piece…
When we say not very specific, we mean there are other reasons the ANA can appear. Wiser age, transient or chronic infections, medications, other autoimmune diseases, among others.
If the ANA comes back, there’s a strong family history of autoimmunity, 80% of the vague symptoms go away or improve dramatically with steroids (steroid response is very nuanced, remind me to speak of this later), the person already went down the mechanical train, the history and physical exam doesn’t bear any fruit and I’m still scratching my head… I may say to myself.
This person has a “forme fruste” or incomplete autoimmune disease and I’ll check other antibodies and labs because perhaps they an early:
Primary Biliary Sclerosis
Phospholipid Antibody Syndrome
Chasing negative ANAs…
Also last important note… ANA does not track with disease activity. There’s a slew of other markers we can use, but ANA is not one of them. So if some alternative provider is telling to chase a negative ANA, that is an exercise in futility, because it can change regardless of what they do and how good or bad you feel.
I told you this was gray.
A too common and unfortunate scenario…
There is also a scenario where the ANA will go negative when a prospective provider is to run it in a patient with say… established Lupus, Sjogren’s, Myositis or whatever and they are told…
“You don’t have the disease.”
“Get out of my office.”
“But… my other doctor said…”
“Your ANA is negative. Take your NSAID. Bye.”
ANA negative lupus and antibody negative autoimmunity exist. The full picture and a thorough history is our most important tool. We treat patients, not pieces of paper.
Sensitive but not specific ; not a good screening tool
1:40 low titer ; 1:1280+ high titer ; interpret with caution
Pattern who cares… unless it’s Saturday night!
ANA negative lupus/autoimmune exists.
Patient history is king, not pieces of paper.
The answer is a duck… maybe a mallard. We can differentiate the subtlety with a strong history taking and time spent with you as a patient.
Do you have an ANA? What did it ultimately mean?