E3 PreliminaryPreliminaryPEM unclearPeer-reviewedMachine draft
Case Report: Neutralization of Autoantibodies Targeting G-Protein-Coupled Receptors Improves Capillary Impairment and Fatigue Symptoms After COVID-19 Infection.
Hohberger, Bettina, Harrer, Thomas, Mardin, Christian et al. · Frontiers in medicine · 2021 · DOI
Quick Summary
This case report describes one patient with long COVID who had ongoing fatigue, loss of taste, and poor blood flow in the eyes after a mild COVID-19 infection. The patient was found to have unusual antibodies that attack certain receptors in the body. When treated with a drug called BC 007 that neutralizes these antibodies, the patient's fatigue, taste, and eye blood flow all improved within days and stayed better for at least 4 weeks.
Why It Matters
This study provides preliminary evidence linking autoimmune mechanisms (GPCR-AAbs) to post-COVID fatigue and microcirculatory dysfunction, two hallmark features of ME/CFS. If validated in larger controlled trials, it could identify a treatable subgroup of ME/CFS patients and offer a mechanistic understanding of how autoimmunity impairs cellular energy metabolism and tissue perfusion.
Observed Findings
- GPCR-AAbs were detected in the patient's serum and functionally inactivated within 48 hours of BC 007 infusion, remaining inactive for 4 weeks.
- Fatigue symptoms improved progressively over the 4-week observation period following BC 007 treatment.
- Loss of taste resolved or improved following treatment.
- Retinal capillary microcirculation in the macula and peripapillary region improved on repeat imaging.
Inferred Conclusions
- GPCR-AAbs may contribute to post-COVID syndrome pathophysiology, including fatigue, taste dysfunction, and microcirculatory impairment.
- Neutralization of GPCR-AAbs via BC 007 may be therapeutically beneficial in patients with post-COVID syndrome and detectable GPCR-AAbs.
- Autoimmune mechanisms targeting G-protein-coupled receptors warrant investigation as a potential mechanistic link between infection and long COVID symptoms.
Remaining Questions
- Does BC 007 benefit patients without detectable GPCR-AAbs, or is efficacy limited to GPCR-AAb-positive patients?
- Do GPCR-AAbs cause post-COVID symptoms, or are they merely markers of immune activation?
- What is the durability of clinical response beyond 4 weeks, and are repeat doses necessary?
What This Study Does Not Prove
This case report cannot establish that GPCR-AAbs cause post-COVID syndrome or ME/CFS, nor can it prove BC 007 is an effective treatment. A single patient may represent coincidental improvement, natural recovery, or placebo response. No control group or randomized design was used, and generalizability to other patients is unknown.
Tags
Symptom:FatigueSensory Sensitivity
Biomarker:CytokinesAutoantibodies
Phenotype:Infection-TriggeredLong COVID Overlap
Method Flag:Weak Case DefinitionNo ControlsSmall SampleExploratory Only
Metadata
- DOI
- 10.3389/fmed.2021.754667
- PMID
- 34869451
- Review status
- Machine draft
- Evidence level
- Early hypothesis, preprint, editorial, or weak support
- Last updated
- 8 April 2026
About the PEM badge: “PEM required” means post-exertional malaise was an explicit required diagnostic criterion for participant inclusion in this study — not that PEM was studied, observed, or discussed. Studies using criteria that do not require PEM (e.g. Fukuda, Oxford) are tagged “PEM not required”. How the atlas works →
Spotted an error in this entry? Report it →