r/myocarditis

#AI-produced post that I thought was worth sharing:

I’ve been reading more about Long COVID recently because there seems to be quite a lot of symptom overlap with what some people experience after myocarditis/myopericarditis: exercise intolerance/PEM, brain fog, disturbed sleep, autonomic symptoms/tachycardia, fatigue and relapses after infections or stress.

Obviously these symptoms don’t mean the underlying biology is necessarily the same, but it made me wonder whether some cases of prolonged post-viral myocarditis/myopericarditis could involve a broader immune dysregulation rather than simply persistent IL-1-type inflammation.

One area that seems interesting is interferon/JAK-STAT signalling and T-cell dysfunction. Long COVID studies have reported persistent immune activation alongside altered/exhausted T-cell phenotypes, interferon signalling, IL-6 pathways, complement abnormalities etc. “T-cell exhaustion” doesn’t simply mean low immunity—it can occur after chronic antigenic stimulation, where T cells remain activated but become functionally altered.

That led me to baricitinib, a JAK1/JAK2 inhibitor. Rather than blocking one cytokine such as IL-1, it reduces intracellular signalling from several cytokine pathways, including interferon-related signalling. There is now a large trial investigating baricitinib specifically for Long COVID, including outcomes such as fatigue, cognition and PEM.

There is also at least some precedent for JAK inhibition in clearly immune-mediated myocarditis. JAK inhibitors have been used in severe immune-checkpoint-inhibitor myocarditis, where T-cell activation is unquestionably central. That is obviously a very different disease from ordinary viral myocarditis, so I’m not suggesting the evidence transfers directly.

But it raises an interesting question for people who have a pattern like:

viral illness → cardiac symptoms/troponin rise → ongoing fatigue/PEM/autonomic symptoms → recurrent post-viral flares,

particularly where CRP/ESR remain normal despite evidence of myocardial injury.

Could a subset have relatively local or interferon/T-cell-driven inflammation that doesn’t generate a big systemic CRP response? And could that explain why treatments aimed primarily at IL-1 or prostaglandins sometimes only partially help?

There are major caveats. Baricitinib is a real immunosuppressant with infection, blood-count, liver and thrombotic considerations, and it is not an established treatment for ordinary myocarditis or Long COVID at present. Persistent viral infection would also complicate the logic of suppressing antiviral immunity. So this definitely isn’t something to self-experiment with.

I’m mainly posting because I think the Long COVID ↔ post-viral myocarditis overlap may be worth more research, particularly around interferon/JAK signalling, T-cell phenotypes and dysautonomia.

Would be interested to know whether anyone here has had detailed immune testing, been treated by an immunologist/rheumatologist, or come across research on JAK inhibitors, hydroxychloroquine, azathioprine/MMF etc. in chronic or recurrent myocarditis rather than the usual acute presentation.