Preprint ACE-2-like Enzymatic Activity in COVID-19 Convalescent Patients with Persistent Pulmonary Symptoms Associated with Immunoglobulin, 2025, Song et al.

ACE-2-like Enzymatic Activity in COVID-19 Convalescent Patients with Persistent Pulmonary Symptoms Associated with Immunoglobulin
Yufeng Song; Frances Mehl; Lyndsey M. Muehling; Glenda Canderan; Kyle Enfield; Jie Sun; Michael Yin; Sarah J. Ratcliffe; Jeffrey M Wilson; Alexandra Kadl; Judith A Woodfolk; Steven L Zeichner

Many difficult to understand clinical features characterize COVID-19 and Post-Acute Sequelae of COVID-19 (PASC or Long COVID, LC). These can include blood pressure instability, hyperinflammation, coagulopathies, and neuropsychiatric complaints. The pathogenesis of these features remains unclear. The SARS-CoV-2 Spike protein Receptor Binding Domain (RBD) binds Angiotensin Converting Enzyme 2 (ACE2) on the surface of host cells to initiate infection.

We hypothesized that some patients may produce anti-RBD antibodies that resemble ACE2 sufficiently to have ACE2-like catalytic activity, that is they are ACE2-like proteolytic abzymes that may help mediate the pathogenesis of COVID-19 and LC. In previous work, we showed that some acute COVID-19 patients had immunoglobulin-associated ACE2-like proteolytic activity, suggesting that some COVID-19 patients indeed produced ACE2-like abzymes. However, it remained unknown whether ACE2-like abzymes were seen only in acute COVID-19 patients or whether ACE2-like abzymes could also be identified in convalescent COVID-19 patients.

Here we show that some convalescent COVID-19 patients attending a clinic for patients with persistent pulmonary symptoms also have ACE2-like abzymes and that the presence of ACE2-like catalytic activity correlates with alterations in blood pressure in an exercise test.


Link | PDF (Preprint: MedRxiv) [Open Access]

 

Follow-up of ACE-2-like enzymatic activity is associated with immunoglobulin in COVID-19 patients (2024, mBio)

Majority male, hospitalised cohort being seen at a post-Covid respiratory clinic.

Cough 40%
Breathing Difficulty 10%
Dyspnea on exertion 80%

Headache 10%
Weakness 15%
Fatigue 60%
Dizzy/Lightheaded/Syncope 20%
Brain fog/Memory Problems 35%
Sleep Disruption 45%
Pain 25%
Numbness 15%

 

They found 6/20 patients had "ACE2-like antibody-associated catalytic activity in their plasma", which doesn't sound very compelling.