COVID and Unmasking Autoimmune Disease

Unless you’re one of the very lucky few who’s escaped COVID-19 so far, there’s a chance you had some lingering after-effects or heard of someone who has. Most of us after the usual cold are going to end up with a few days of the “blahs” i.e. a bit more drowsy than usual, maybe a bit of a runny nose, cloudy thinking, and many are going to be stuck with a cough that might last for weeks. That’s the normal post-flu, post-cold type of thing. Odds are you’ve also heard of some folks having much longer, lingering effects following their COVID infection and, sadly in some cases, some are having symptoms stretching out more than 3 years since the first cases were reported in humans. The concept is called “long COVID”, and it’s a whole topic itself and still a hot area of research into late 2023 since we don’t understand it.

There’s a lesser-talked about post-COVID issue that you or a friend, family member might have come across (or you’ve seen a rheumatologist for): new autoimmune disease after COVID-19 (or in some cases, from vaccination to it).

COVID-19 infections and autoimmune/rheumatic disease

Over the last 3 years, there’s a been a slow and steady stream of new onset autoimmune/rheumatologic diseases I’ve seen in my clinic that followed a COVID infection or, again in some cases, the vaccines to it. It’s become such a common phenomenon that I’ve changed my the way I screen patients for these, now asking something like: “in the 1-3 months before you started having symptoms of this thing, did you have COVID or feel sick otherwise? Did you get any vaccines or boosters just prior?”.

Say COVID runs its way through a family, everyone thankfully recovers well from the immediate infection, but say 3 weeks, 4 weeks later, the joints start to stiffen, maybe swell. Maybe a subtle rash appears on the legs. Maybe ulcers start appearing in the mouth. Naturally, our minds don’t immediately go and associate that viral illness to these weird symptoms that show up a month, sometimes two or three months later even – after all, things like colds generally hit us all the time (especially if you have young kids like we do – daycare, we’re constantly sick!). Hard to blame a really unique set of symptoms, like swollen joints or odd rashes, to viral infections that we’re so used to getting so dang regularly (COVID or not). When you start asking the question of timing though, especially for COVID infections, there’s a pattern, a correlation between the two that starts to become clearer when you’re seeing it over and over – COVID infections in a very small number of cases seems to be unmasking, unveiling autoimmune/rheumatic diseases.

This isn’t just my clinic, I’m by far not the only one to notice this: this has been out there in the published COVID-19 literature since 2021, at least, and is being published regularly since. These autoimmune diseases, as it turns out, cover the whole gamut: a group in Mexico led by Gracia-Ramos in 2021 categorized these types of diagnoses and found they ran the whole spectrum from rheumatoid arthritis on one end ranging to a whole-body inflammatory disease called vasculitis, and everything between (lupus, muscle disease, more). A Taiwanese group found something similar earlier in the same year. More recently, bigger compilations of data are seeing first time Crohn’s disease, ulcerative colitis, multiple sclerosis, alopecia (hair loss!), and many others.

How? There’s a few ideas out there but it’s hard to nail down a single explanation since not all autoimmune diseases are alike. One of the leading ideas is a concept called molecular mimicry, whereas to the “eyes” of our immune system, parts of a viral component look just like components of our own cells and tissue. We mount an immune response to the virus and we inadvertently mount a response to ourselves at the same time: collateral damage. This happens more often than you might think; the bug behind strep throat, for instance, is pretty infamous for doing this exact thing and causing havoc via molecular mimicry (rheumatic fever!).

An important point to realize is it’s not everyone that’s coming down with a devastating autoimmune disease like lupus after a COVID-19 infection, it’s rare. The exact rate is one that we can’t realistically measure but one of the best estimates comes from a South Korean study (Sung Ha Lim) looking at just under 7 million individuals, some 300,000 of those having had COVID-19 in the window of the study, and seeing who got diagnosed with an autoimmune disease after. The rate of each autoimmune disease varied pretty widely, but even one of the most common diagnoses (autoimmune hair loss i.e. alopecia areata) came in at an extremely rare 0.11% chance, as in those infected had a 0.11% chance of developing it after a COVID-19 infection. They also found if you were sicker, particularly if you were sick enough to need ICU-level care, that risk of coming down with an autoimmune disease after was higher.

What about COVID-19 vaccines?

What about vaccinations, can these draw out autoimmune diseases too? It’s a pretty certain “yes” based on experience and the literature we have.

The vaccines are doing their job correctly: they’re exposing the body to a benign particle belonging to the COVID-19 virus and then they ramp up the body’s immune response so the body has a lasting memory of that particle. The next time your body sees that particle in the wild, say with an actual COVID-19 infection, your immune system is already primed and can take it down dramatically faster and with far less lasting harm – that’s all established.

Somewhere along that expected process though, a very small number of us is getting into trouble: in published cases up to August 2022, there were 928 cases published in the academic literature of either new or relapsed autoimmune disease following a COVID-19 vaccination (all vaccines, mRNA or not) – while that reported number is probably seriously underestimating the real amount, that’s still certainly a tiny number compared to the 64% of the global population that was estimated to be vaccinated by September 2022.

What’s a bit less clear here is exactly how the vaccines are promoting some of the same autoimmune issues that the full infection is known for doing: is this molecular mimicry also, as in are the vaccines representing the same protein that end up causing trouble with mimicry during a real COVID-19 infection? Maybe. Alternatively, usual immune responses to any viral infection all start in a similar fashion and predictably stir up a sequence of signals and inflammation that helps shut that infection down: in someone who’s susceptible, is simply firing up that mechanism pushing them over the edge and revealing an autoimmune syndrome? Also possible. We don’t know exactly what’s occurring here yet.

I want to be crystal clear however: in no way do I want to convey the idea that since vaccination against COVID-19 might bring some of these autoimmune diseases to the surface, I’m by no means advocating avoiding them. The concept is that any vaccine, COVID-19 vaccines included, are a mild, benign, or otherwise disabled version of the virus (or bacteria in some cases). It’s not doing anything unique to you that the actual infection itself wouldn’t do 10-fold, 100-fold, maybe 1000-fold or more in severity. In other words, if you skipped the vaccine hoping to avoid bringing out an autoimmune disease that you may otherwise have been destined (genetically or otherwise) to develop, it’s fully reasonable and expected it’d develop just the same (and possibly hit you much harder) when you eventually get the actual infection or get reinfected.

What else kicks off an autoimmune disease? What can do we do to avoid any of this?

There isn’t too much we can do to avoid it fully, I’m afraid. Like I said above, the numbers don’t stack up to skip out on a COVID-19 (or any, really) vaccine for the sake of trying to avoid it stimulating your immune system. If the vaccine doesn’t do it, the actual infection will (and it’ll kick you a lot harder when it finally hits).

This gets into a whole different subject of what triggers autoimmune disease in general, but this stimulation, this “jolt” to our immune system that might lead a susceptible person into autoimmune trouble doesn’t necessarily need to be infectious at all (and in fact very often it’s not). Preceding an autoimmune diseases first symptoms, we’ll regularly see prolonged physical or mental stress (we see this a lot in those taking care of sick family members, homelessness, financial struggles, and many, many, many more), surgery, pregnancy (usually AFTER the pregnancy is a common time for these things to erupt!), trauma like a car accident or serious fall, smoking, drug use… you can imagine others, basically any substantial threat or insult to the body we react to by firing up that immune system briefly so it can protect us from whatever that threat is (if need be). In a susceptible person (maybe genetically-predisposed or otherwise), when exposed to the threat/insult at just the wrong time, this can spell trouble.

So, no one is avoiding all of the above “jolts” that can ramp our immune system up, not all of them and not all the time. We live too stressful, busy lives and certainly don’t live in isolated, safe bubbles. What we can do and have some control of (and which may make a difference), is to live as healthily as possible – give ourselves all the advantages we can to reduce the impact of any one of these “kicks”. That means we try our best to be physically fit, find healthy outlets for stress (no way we can fully avoid stress, I wish we could!), cut out anything that’s really an excess/harmful load on our health (smoking, excess drinking), have healthy nutrition the best we can, and maintain good social relationships. Think of this as strapping your armor on for the next time something stressful, traumatic, or infectious comes your way – living well can’t fully prevent an outcome from happening, but it certainly gives you the best chance to either dodge it or soften the blow.