Can anti-CHRM autoantibodies cause Long COVID? Understanding the Link and Future Treatments

by LCJ Team, posted in Symptoms and Complications

Researchers have identified anti-muscarinic cholinergic receptor (anti-CHRM) autoantibodies in some people with Long COVID, particularly those with symptoms affecting the autonomic nervous system. These antibodies may interfere with signalling involved in heart rate, blood pressure, digestion and other automatic body functions. However, it is still unclear whether they directly cause symptoms, are a consequence of the illness, or occur only in a subgroup of patients. At present, testing remains a research tool rather than part of routine clinical care.

Last updated July 2026

Key Takeaways

  • Anti-CHRM antibodies are one type of GPCR autoantibody.
  • They may affect autonomic function.
  • They have been found in some Long COVID patients.
  • They are not present in everyone.
  • No routine clinical test exists.
  • Researchers are investigating whether they could help identify biological subtypes or future treatments.

If you’ve been researching Long COVID, you may have come across the term anti-CHRM autoantibodies or muscarinic receptor antibodies. Some researchers believe these unusual antibodies could help explain why certain people develop symptoms such as dizziness, palpitations, brain fog and digestive problems long after the initial infection has passed. Others argue that they may simply be one feature of a much more complex illness. So, what exactly are anti-CHRM autoantibodies, why are scientists interested in them, and could they eventually lead to new tests or treatments for Long COVID? While many questions remain unanswered, this area has become one of the most active fields of Long COVID research.

What Are Anti-CHRM Autoantibodies?

Before understanding anti-CHRM autoantibodies, it helps to understand what an autoantibody is. Normally, antibodies recognise viruses and bacteria to help protect the body. Autoantibodies are different. Instead of targeting infections, they mistakenly bind to the body’s own tissues.

Anti-CHRM autoantibodies target muscarinic cholinergic receptors, a family of receptors found throughout the body. These receptors help regulate many automatic functions that we rarely think about, including heart rate, blood pressure, digestion, tear production, bladder function and aspects of cognitive performance.

Because these receptors form part of the autonomic nervous system, researchers have questioned whether antibodies that interfere with their normal function could contribute to symptoms seen in some people with Long COVID.

Why Does This Matter?

One of the biggest mysteries of Long COVID is why symptoms vary so dramatically between individuals. Some people mainly experience fatigue, while others develop orthostatic intolerance, rapid heart rate, digestive problems or cognitive difficulties.

Interestingly, many of these symptoms involve systems controlled by the autonomic nervous system. Because muscarinic receptors play an important role in regulating these functions, researchers began investigating whether antibodies directed against these receptors might help explain why some patients develop persistent autonomic dysfunction.

How Do They Affect the Body?

If these antibodies interfere with muscarinic receptors, they could potentially alter signalling in several organ systems. Researchers have suggested this might contribute to symptoms such as dizziness when standing, rapid heart rate, digestive disturbance, bladder symptoms, dry eyes, dry mouth and cognitive dysfunction. However, it is important to remember that these mechanisms remain under investigation. Finding an antibody does not automatically prove that it is responsible for a person’s symptoms.

Over the past few years, several research groups have identified anti-CHRM and other functional autoantibodies in subsets of people with Long COVID, particularly those with dysautonomia or symptoms resembling POTS and ME/CFS. These findings have generated considerable interest because similar antibodies have previously been described in several autoimmune and autonomic disorders.

At the same time, the evidence remains mixed. Some studies have detected these antibodies more frequently than expected, while others have found weaker or inconsistent associations. Researchers still do not know whether these antibodies directly cause symptoms, develop as a consequence of tissue damage, or simply identify one biological subtype of Long COVID.

Could These Antibodies Lead to New Treatments?

If future research confirms that anti-CHRM autoantibodies play a causal role in some patients, they could eventually help guide more personalised treatments. Researchers are investigating several immune-targeted therapies, including IVIG, immunoadsorption, plasmapheresis and medicines that modify B-cell activity. However, none of these treatments has yet been proven effective specifically because of anti-CHRM autoantibodies, and they remain experimental for Long COVID.

Why Continued Research Is Vital

Too many patients still hear that Long COVID is “all in their head”. The science disagrees. One of the most exciting possibilities is that autoantibodies such as anti-CHRM could eventually help identify biological subtypes of Long COVID. Rather than relying solely on symptoms, future doctors may be able to combine blood biomarkers with clinical features to better understand which biological mechanisms are driving an individual’s illness. However, this remains a research goal rather than current clinical practice.

 A Final Word (With a Wink)

Anti-CHRM autoantibodies are one of the most intriguing discoveries in Long COVID research, but they are not yet the missing piece of the puzzle. Current evidence suggests they may contribute to symptoms in a subgroup of patients, particularly those with autonomic dysfunction, but much remains uncertain. Rather than proving that all Long COVID is autoimmune, these findings support the growing idea that Long COVID consists of several biological subtypes. Understanding those differences may ultimately lead to more accurate diagnosis, better targeted treatments and truly personalised care.

FAQ

Can doctors test for anti-CHRM antibodies?

Not routinely. While anti-CHRM autoantibodies can be measured in some research laboratories, there is currently no widely accepted clinical test used to diagnose Long COVID. Researchers are still determining how reliable these antibodies are as biomarkers and whether they can meaningfully guide treatment.

Do anti-CHRM antibodies prove that Long COVID is an autoimmune disease?

No. They provide evidence that autoimmune mechanisms may contribute to illness in some people, but they do not explain every case of Long COVID. Most researchers now believe Long COVID is likely made up of several biological subtypes, with autoimmunity being one possible mechanism among others such as viral persistence, immune dysregulation and vascular dysfunction.

Can treatments remove these antibodies?

Some experimental treatments, including immunoadsorption, plasmapheresis, IVIG and investigational drugs such as BC007, aim to reduce or neutralise harmful autoantibodies. However, these treatments remain experimental for Long COVID, and there is currently no approved therapy specifically targeting anti-CHRM antibodies.

Reference
Würtzner, L., & Prusty, B. (2025). Anti-muscarinic cholinergic receptor autoantibodies in Long COVID: Mechanisms and implications. Journal of Medicinal Chemistry.

Wallukat G, Hohberger B, Wenzel K, et al. Functional autoantibodies against G-protein coupled receptors in Long COVID.Szewczykowski C, et al. GPCR autoantibodies and autonomic dysfunction in post-COVID syndrome.Würtzner L, Prusty BK, et al. (your featured paper, if published).

Disclaimer
This article is for informational purposes only and is not a substitute for professional medical advice. Always speak to your healthcare provider about any concerns or symptoms.

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