Persistent Presence of Spike protein and Viral RNA in the Circulation of Individuals with Post-Acute Sequelae of COVID-19, 2022, Craddock+

[SNT Gatchaman]

Persistent Presence of Spike protein and Viral RNA in the Circulation of Individuals with Post-Acute Sequelae of COVID-19
Vaughn Craddock, Aatish Mahajan, Balaji Krishnamachary, Leslie Spikes, PrabhakarChalise, Navneet Kaur Dhillon

SARS-CoV-2, the causative agent of COVID-19 disease has resulted in the death of millions worldwide since the beginning of the pandemic in December 2019. While much progress has been made to understand acute manifestations of SARS-CoV-2 infection, less is known about post-acute sequelae of COVID-19 (PASC).

We investigated the levels of circulating SARS-CoV-2 components, Spike protein and viral RNA, in patients hospitalized with acute COVID-19 and in patients with and without PASC. In hospitalized patients with acute COVID-19 (n=116), we observed a positive correlation of Spike protein with D-dimer, length of hospitalization, and peak WHO score while viral RNA correlated with a tissue injury marker, lactate dehydrogenase (LDH).

When comparing patients with post-COVID symptoms (n=33) and patients without (n=14), we found that Spike protein and viral RNA were more likely to be present in patients with PASC and in some cases at higher levels compared to acute COVID-19 patients. We also observed that the percent positivity of circulating viral RNA increased in the PASC positive individuals compared to acute COVID-19 group while Spike protein positivity remained the same.

Additionally, we report that part of the circulating Spike protein is linked to extracellular vesicles without any presence of viral RNA in these vesicles.

Our findings suggest that Spike protein and/or viral RNA fragments persist in the recovered COVID-19 patients with PASC, independent of their presence or absence during the acute COVID-19 phase.

MedRxiv | Preprint PDF

 

[SNT Gatchaman]

University of Kansas Medical Center. Some quotes from their intro, results and discussion —

We report that both viral RNA and/or Spike protein remain in circulation long after acute infection (more than one-year post-infection in some cases) and this persistent circulation of viral components is associated with PASC. Further, we show the presence of Spike protein, but not viral RNA, in plasma-derived small EVs from individuals with acute or long-COVID-19.

Some of the samples that had circulating Spike protein did not have detectable levels of viral RNA, while other samples that had viral RNA did not have detectable Spike protein. [...] This suggests that Spike protein may be freely circulating independent of circulating virions and circulating viral RNA may include free viral RNA or its fragments during acute infection with SARS-CoV-2.

When we examined the Spike protein levels in the EVs from the plasma samples that showed positivity for Spike protein, 53% (8/15) of samples from the PASC+ve group showed presence of EV-linked Spike protein and these levels were almost at a similar level as that observed in acute COVID-19 patients. Interestingly, EVs from the PASC-ve group did not show any positivity for Spike protein ELISA.

[...] Spike protein interacts with heparan sulfate through the receptor binding domain. [...] Heparinase II treatment of COVID-19 EVs showed decreased levels of Spike protein when compared to untreated EVs [...] where as CD81 and CD9 tetraspanins were still present on EVs after heparinase II treatment. This suggests specific interactions of Spike protein on EV surfaces.

[..] we also report that circulating Spike protein can be linked to EVs in the absence of viral RNA in the vesicles. These results suggest that the persistence of Spike protein and/or viral RNA could be contributing factors for the development of PASC.

Our results revealed that most patients did not have both Spike protein and viral RNA in plasma simultaneously, suggesting that the persistence of viral particles is probably not due to actively replicating virus.

It is now widely recognized that endothelial dysfunction and micro-thromboses play a significant role in acute infection and we see further evidence of this with our finding that D-dimer is positively correlated with circulating levels of total plasma Spike protein (p=0.0249) and EV- associated Spike protein (p<0.01) across all three groups of acute COVID-19 severity.

Park et al recently reported that D-Dimer can also form immune complexes with SARS- CoV-2 Spike protein and bound antibodies resulting in activation of monocytes to produce proinflammatory cytokines.

[...] we showed increased levels of Spike protein in PASC+ve patients, indicating that Spike protein-driven endothelial activation may persist and perhaps contribute to increased risk of clotting and endothelial dysfunction during PASC.

Here, we observed that EVs carry Spike protein in both acute COVID-19 and PASC patients. Given that SARS-CoV-2 replicates in cytosol using endosomal pathway and we observed Spike protein associated with EVs, it may be possible for SARS-CoV-2 to usurp EV biogenesis pathways and conceal itself within EVs as protection against neutralizing antibodies.

 

[alex3619]

This raises the possibility, which has been noted before, that ME like symptoms might arise due to failure to fully clear a pathogen, even if active infection is over. Eventually it is most likely cleared, but prolonged exposure might drive symptoms long after it is fully cleared due to physiological changes.

It is unclear whether or not latent infection is involved. It remains a possibility, but for ME at least I think its unlikely for most patients unless its an Herpes virus. I would not want to say latent infection is impossible for all patients, nor for all pathogens.

 

[LarsSG]

Circulating spike protein in 64% of PASC patients seems like a pretty significant finding (though they also found spike in 29% of non-PASC patients). For the PASC patients, the blood samples were taken 18 weeks or more after infection. It's not totally clear, but I think samples from the no PASC group were taken 24 weeks or more after infection.

"Parallel evaluation of Spike protein in the plasma also found the presence of Spike protein in 4 of 14 PASC-ve individuals and 21 of 33 of PASC+ve (64%) samples (Figure 2B) and the levels were within the range of the levels observed in acute COVID-19 samples. Additionally, we found that in PASC+ve group 33% (11/33) samples showed positivity for both Spike protein as well as viral RNA in plasma, 30% (10/33) for only Spike protein and 18% (6/33) for only viral RNA. However, in the PASC-ve group, none of the samples showed positivity for both Spike protein and viral RNA."

Somewhat similar findings to Swank et al from a couple months ago.

 

[SNT Gatchaman]

Published as —

Persistent circulation of soluble and extracellular vesicle-linked Spike protein in individuals with postacute sequelae of COVID-19
Vaughn Craddock; Aatish Mahajan; Leslie Spikes; Balaji Krishnamachary; Anil K. Ram; Ashok Kumar; Ling Chen; Prabhakar Chalise; Navneet K. Dhillon

SARS‐CoV‐2, the causative agent of COVID‐19 disease, has resulted in the death of millions worldwide since the beginning of the pandemic in December 2019. While much progress has been made to understand acute manifestations of SARS‐CoV‐2 infection, less is known about post‐acute sequelae of COVID‐19 (PASC).

We investigated the levels of both Spike protein (Spike) and viral RNA circulating in patients hospitalized with acute COVID‐19 and in patients with and without PASC.

We found that Spike and viral RNA were more likely to be present in patients with PASC. Among these patients, 30% were positive for both Spike and viral RNA; whereas, none of the individuals without PASC were positive for both. The levels of Spike and/or viral RNA in the PASC+ve patients were found to be increased or remained the same as in the acute phase; whereas, in the PASC−ve group, these viral components decreased or were totally absent. Additionally, this is the first report to show that part of the circulating Spike is linked to extracellular vesicles without any presence of viral RNA in these vesicles.

In conclusion, our findings suggest that Spike and/or viral RNA fragments persist in the recovered COVID‐19 patients with PASC up to 1 year or longer after acute SARS‐CoV‐2 infection.

Link | PDF (Journal of Medical Virology)