BREAKING! Researchers Present Case Reports Of Long COVID Patients With Persistence Of Residual SARS-CoV-2 Antigen And RNA In Various Tissues!
: Researchers from the Institute of Molecular and Cell Biology (IMCB) at the Agency for Science, Technology and Research (ASTAR) - Singapore, Long Covid Autonomous Comm unities Together Spain (Research Group) Madrid -Spain, Vetcare Hospital Veterinario Madrid -Spain, Singapore General Hospital, Cancer Science Institute of Singapore and the Singapore Immunology Network (SIgN) presented documented cases of two Long COVID patients that had persistence of residual SARS-CoV-2 antigen and RNA in various tissues!
The study team found the presence of the residual SARS-CoV-2 virus in the appendix, skin, and breast tissues of 2 patients who exhibited Long COVID symptoms 163 and 426 days after symptom onset.
Thailand Medical News has been warning about how SARS-CoV-2 viral persistence is a major issue that needs to be addressed and that current protocols to deem that a person has recovered from the SARS-CoV-2 infection is a complete nonsensical as current nasal or saliva swab test do not suffice as the virus can hide in reservoirs in deep tissues and the various organs.
We covered a variety of studies to prove our point.
Despite our warnings and articles, no one really did bother or paid attention about SARS-CoV-2 viral persistence till the U.S. NIH were forced to published their study findings in December 2021 that showed SARS-CoV-2 viral persistence is indeed a common and serious occurrence!
But even then, till now, strangely many researchers, health authorities and physicians are reluctant to touch on this issue and are avoiding to deal with this critical issue of viral persistence that is actually a silent killer!
A few other studies have since emerged about SARS-CoV-2 persistence.
According to past COVID-19 News
coverages, the WHO or World Health Organization has defined long COVID-19 (LC) as a condition that occurs in individuals with a history of SARS-CoV-2 infection who exhibit persistent symptoms after its acute phase that last for at least two months and cannot be explained by an alternative diagnosis.
In fact, we at Thailand Medical News believe that Long COVID is simply caused by viral persistence and also by non-genomic viral peptides that are produced during replication and have an ability to bind to critical human host proteases!
The study team from Singapore and Spain had had previously reported residual viral antigens in tissues of convalescent patients and aimed to assess the presence of such antigens in long COVID tissues.
In this new study, the study team established the presence of the residual virus in the appendix, skin, and breast tissues of 2 patients who exhibited LC symptoms 163 and 426 days after symptom onset.
Using multiplex immunohistochemistry, the study team detected viral nucleocapsid protein in all three tissues.
Interestingly, the nucleocapsid protein was further observed to colocalize with macrophage marker CD68, suggesting that immune cells were direct targets of SARS-CoV-2.
Furthermore, by using RNAscope, the presence of viral RNA was also detected.
The team’s positive finding in the breast tissue is corroborated by the recent reports of immunocompromised patients experiencing Long COVID symptoms and persistent viral replication.
The study findings and emerging Long COVID studies raise the possibility that the gastrointestinal tract may also function as a reservoir for SARS-CoV-2.
Convalescent patients often test negative for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Yet, multiple reports have described the persistence of viral RNA and/or antigen(s) in the tissues of these patients particularly in gastrointestinal tissues and fecal samples.
Though surprising, the gastrointestinal tract is a major viral shedding route with high expression of ACE2.
The gastrointestinal tract It has garnered attention in the field of COVID-19 pathophysiology and is proposed to function as a viral reservoir for SARS-CoV-2.
Residual SARS-CoV-2 detected in the breast tissue of patient 2 using multiplex immunohistochemistry and RNAscope (A) Representative images of the breast tissue stained with hematoxylin and eosin, with differentiated staining of nuclear (hematoxylin) and cytoplasmic (eosin) components. (B) Representative images of the breast tissue stained for DAPI (blue), CK/EpCAM (red), CD45 (cyan), SARS-CoV-2 nucleocapsid protein (COVID NP; green), and CD68 (yellow). (C) Representative images of the breast tissue stained for DAPI (blue), SARS-CoV-2 nucleocapsid protein (COVID NP; green), and CD68 (red). (D–F) Representative images of (D, E) the breast tissue obtained from patient 2 and (F) normal breast tissue obtained from patients not affected by COVID-19, subjected to RNAscope in situ hybridization with a nuclear component (hematoxylin) counterstained. SARS-CoV-2 spike RNAs are labelled as green dots, examples of the green dots are marked by black arrows. (A–C) Scale bar, 100 μm. (D–F) Scale bar, 20 μm.
The study team previously reported the persistence of residual SARS-CoV-2 RNA and antigens for up to 180 days in the gastrointestinal tissues of convalescent patients with COVID-19.
The study findings of the current study are published in the peer reviewed journal: Frontiers in Immunology.
The study team experiments on tissues obtained from two LC patients using multiplex immunohistochemistry and RNAscope.
In Case Report One,
a 44-year-old woman with peritonitis and appendiceal lymphoid hyperplasia presented with acute symptoms (low grade fever of 37.3°C, pharyngitis, choking, bronchospasm and dysphagia, loss of smell and taste, anorexia, expectoration, migraine headache, chills in the spinal cord, palate petechiae, nausea and diarrhea, weight loss by 8.5%, etc.) on 7 March 2020 and was diagnosed with COVID-19 via serology testing.
It was reported that on 11 May 2020, the patient received her first negative polymerase chain reaction (PCR) test result, although her symptoms persisted.
However, a year later, on 4 May 2021, the patient presented with generalized abdominal pain, loss of appetite, and nausea. Urgent exploratory laparotomy and appendectomy were performed, and tissue histology showed reactive lymphoid hyperplasia.
A detailed biopsy of the skin of the lower limb was also obtained, and the patient was diagnosed with superficial and deep perivascular dermatitis. Before the procedures, the patient had a negative PCR test result for SARS-CoV-2.
The female patient’s appendix and skin tissue were obtained 426 days after initial symptom onset.
Utilizing multiplex immunohistochemistry, SARS-CoV-2 nucleocapsid proteins (NP) and spike proteins were detected in the appendix, co-localized with myeloid and macrophage markers CD68, CD14, CD206, and CD169.
The study findings support prior investigation, in which residual viral antigens were consistently detected in the gastrointestinal tissues (colon, appendix, ileum) of a patient and were co-localized in ACE2+CD68+ cells. https://pubmed.ncbi.nlm.nih.gov/34083386/
However, having no access to the colon and ileum, the study team then examined the skin as a non-gastrointestinal tissue to further study SARS-CoV-2 distribution in a single patient.
Shockingly, viral NP was also detected in skin macrophages. The specificity of the used antibody was reported in their previous study.
After having established the presence of the residual viral antigen in the appendix and skin tissues, the study team then aimed to assess its genomic presence. Using RNAscope in situ hybridization, the study team detected viral RNA within both extracellular and intracellular space of the appendix, providing evidence of viral persistence for up to 426 days after symptom onset. This technique was not performed on the skin tissue due to limited tissue availability. The specificity of the used probe was tested on normal colon tissue obtained from an independent cohort in 2018 or earlier.
Case Report Two
involves a 45-year-old woman with ductal carcinoma in situ presented with acute symptoms (intensive headache, upper stomach pain, nausea, diarrhea, myalgias, and fatigue, etc.) on 14 March 2020 and was diagnosed with COVID-19 via PCR.
The patient reported that several of her symptoms worsened over the next two months.
It was noted that on 8 May 2020, the patient received her first negative PCR test result for SARS-CoV-2, although the symptoms persisted.
It was reported that on 12 August 2020 and 1 September 2020, the patient underwent partial breast resection and margin control surgery, respectively. Before the procedures, the patient underwent preoperative PCR testing for SARS-CoV-2 and received a negative result.
Breast tissue specimens were obtained from the patient 175 days after symptom onset further to investigate the presence of viral antigens and RNA in non-gastrointestinal tissues.
Utilizing same techniques used for patient 1, viral NP and spike protein was detected and observed in the tumor-adjacent area.
Again, these viral antigens also co-localized with myeloid and macrophage markers CD68, CD14, CD206, and CD169.
SARS-CoV-2 Viral RNA was also detected in the breast, within both the extracellular space of the tissue and within the cells.
Similar to patient 1, the specificity of the used antibody was reported in the study team’s previous study. https://pubmed.ncbi.nlm.nih.gov/34083386/
This specificity of the used probe was tested on normal breast tissue obtained from an independent cohort in 2018 or earlier.
The study findings present two cases of Long COVID (LC) with persistent viral antigen and/or RNA. Patient 1 harbored residual SARS-CoV-2 in both gastrointestinal and non-gastrointestinal tissues, while patient 2 in non-gastrointestinal tissues only due to the nature of surgery. Both patients experienced symptoms related to the gastrointestinal tract, such as inflammatory bowel disease, loss of appetite, and abdominal pain.
The study team believes that these two cases are the first to report detected viral antigen and/or RNA in the tissues of patients with Long COVID (LC).
Despite the lack of definitive consensus on the underlying pathophysiology of LC, emerging evidence suggests that LC is associated with gut dysbiosis and aberrant immune activation in response to residual virus.
However, a growing body of evidence also suggests and supports the possibility that the gastrointestinal tract may serve as a SARS-CoV-2 reservoir in both convalescent and LC patients.
A recent study investigating the association between SARS-CoV-2 viral persistence and LC, patients negative for mucosal SARS-CoV-2 RNA (30%) did not experience LC symptoms. Notably, amongst patients that tested positive (70%), majority (65.5%) experienced LC symptoms.
Such findings not only support the above notion of viral persistence in the gastrointestinal tract, but also additionally associates viral persistence with LC symptoms. Further understanding of the immunity of the gastrointestinal mucosa could provide insight into the underlying pathophysiology of LC. The presence of residual SARS-CoV-2 in non-gastrointestinal tissues, such as skin and breast, also warrants further investigation of viral distribution across different organs in patients with LC.
Although the two presented cases have kickstarted the investigation of residual SARS-CoV-2 in the tissues of LC patients, future studies should confirm the observations.
Urgent studies are needed to further validate viral persistence as the driving factor behind Long COVID and also more importantly, more urgent studies and resources are need to find solutions as to how to eradicate or deal with SARS-CoV-2 persistence which we at Thailand Medical News classifies as a dangerous silent killer. In fact, we hypothesize that most individuals exposed to the virus will only have like 5 to 8 years left before they succumb to a variety of fatal outcomes as hundreds of cellular pathways, genes, tissues and various organs are being disrupted or damaged by the SARS-CoV-2 virus.
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