Retraction Note: Presence of viral spike protein and vaccinal spike protein in the blood serum of patients with long-COVID syndrome.

The article "Presence of viral spike protein and vaccinal spike protein in the blood serum of patients with long-COVID syndrome", by K. Dhuli, M.C. Medori, C. Micheletti, K. Donato, F. Fioretti, A. Calzoni, A. Praderio, M.G. De Angelis, G. Arabia, S. Cristoni, S. Nodari, M. Bertelli, published in Eur Rev Med Pharmacol Sci 2023; 27 (6 Suppl): 13-19-DOI: 10.26355/eurrev_202312_34685-PMID: 38112944 has been retracted by the Editor in Chief for the following reasons. Following some concerns raised on PubPeer, the Editor in Chief has started an investigation to assess the validity of the results. The outcome of the investigation revealed that the manuscript presented major flaws in the following: -       Unclear methodology and patient recruitment -       Discrepancies among data reported in the text and tables -       Unreliable results -       Undeclared conflict of interest Consequently, the Editor in Chief mistrusts the results presented and has decided to withdraw the article. The authors disagree with this retraction. The Publisher apologizes for any inconvenience this may cause. https://www.europeanreview.org/article/34685.

Presence of viral spike protein and vaccinal spike protein in the blood serum of patients with long-COVID syndrome.

OBJECTIVE: COVID-19 patients experience, in 10-20% of the cases, a prolonged long-COVID syndrome, defined as the persistence of symptoms for at least two months after the infection. The underlying biological mechanisms of this syndrome remain poorly understood. Several hypotheses have been proposed, among which are the potential autoimmunity resulting from molecular mimicry between viral spike protein and human proteins, the reservoir and viral reproduction hypothesis, and the viral integration hypothesis. Although official data state that vaccinal spike protein is harmless and remains at the site of infection, several studies proposed spike protein toxicity and found it in blood circulation several months after the vaccination. To search for the presence of viral and vaccine spike protein in a cohort of long-COVID patients. PATIENTS AND METHODS: In this study, we employed a proteomic-based approach utilizing mass spectrometry to analyze the serum of 81 patients with long-COVID syndrome. Moreover, viral integration in patients' leukocytes was assessed with a preliminary study, without further investigation. RESULTS: We identified the presence of the viral spike protein in one patient after infection clearance and negativity of COVID-19 test and the vaccine spike protein in two patients two months after the vaccination. CONCLUSIONS: This study, in agreement with other published investigations, demonstrates that both natural and vaccine spike protein may still be present in long-COVID patients, thus supporting the existence of a possible mechanism that causes the persistence of spike protein in the human body for much longer than predicted by early studies. According to these results, all patients with long-COVID syndrome should be analyzed for the presence of vaccinal and viral spike protein.

Linking pathogenic and likely pathogenic gene variants to long-COVID symptoms.

OBJECTIVE: Long-COVID is a clinical syndrome characterized by the presence of symptoms related to SARS-CoV-2 infection that persist for at least four weeks after recovery from COVID-19. Genetics have been proposed to play an important role in long-COVID syndrome onset. This study aimed to identify genetic pathogenetic and likely pathogenetic causative variants of Mendelian genetic diseases in patients with Long-COVID syndrome. Additionally, we aimed to establish an association between these genetic variants and the clinical symptoms manifested during long-COVID syndrome. PATIENTS AND METHODS: 95 patients affected by long-COVID syndrome were analyzed with a Next-Generation Sequencing (NGS) panel comprising 494 genes. The analyzed genes and the symptoms of the patients collected with an ad-hoc questionnaire were divided into four groups (cardiological, respiratory, immunological, and neurological). Finally, a statistical analysis comprising descriptive statistics, classification based on reported symptoms, and comparative analysis against a control group of healthy individuals was conducted. RESULTS: 12 patients resulted positive for genetic testing with an autosomal dominance (8) or autosomal recessive (4) inheritance, showing a higher prevalence of cardiovascular genetic diseases (9) in the analyzed cohort compared to the normal population. Moreover, the onset of the long-COVID syndrome and its cardiovascular manifestations was compliant with the onset reported in the literature for the identified genetic diseases, suggesting that COVID-19 could manifest late-onset genetic diseases associated with their appearance. Apart from the 12 positive patients, 57 were healthy carriers of genetic diseases. Analyzing the whole cohort, a statistical correlation between prevalent symptomatology and the gene class was established, suggesting an association between the genetic susceptibility of an individual and the possibility of developing specific long-COVID syndrome symptoms, especially cardiovascular symptoms. Furthermore, 17 genetic variants were identified in CFTR. Finally, we identified genetic variants in IFNAR2 and POLG, supporting their respective involvement in inflammation and mitochondria mechanisms, correlated with long-COVID syndrome according to literature data. CONCLUSIONS: This study proposed COVID-19 to act as a manifest of underlying late-onset genetic diseases Mendelian associated with carrier status. Moreover, according to our results, mutations in cardiological genes are more present in patients who show cardiological symptoms during the syndrome. This underscores the necessity for cardiological investigation and genetic screening in long-COVID patients to address existing or potential clinical implications.

Autoantibodies in patients with post-COVID syndrome: a possible link with severity?

OBJECTIVE: Coronavirus disease 2019 is an infectious disease associated with the respiratory system caused by the SARS-CoV-2 virus. Right now, an increasing number of patients with Post-COVID Syndrome show, without clear evidence of organ dysfunction, a plethora of severe symptoms, such as fatigue, pain, shortness of breath, cognitive impairment, and sleep disturbance. It has already been demonstrated that SARS-CoV-2 virus can disrupt the self-tolerance mechanism of the immune system, thus triggering autoimmune conditions. Several studies have recently documented the presence of autoantibodies in the sera of post-COVID patients, but until now, it is unclear whether the persistence of symptoms could be directly correlated with the presence of autoantibodies. PATIENTS AND METHODS: In this study, serum autoantibodies (AAbs) levels against four G protein-coupled receptors in 78 patients with post-COVID syndrome have been analyzed. The AAbs investigated are clustered in two groups: adrenergic receptors (α1 and ß2) and muscarinic acetylcholine receptors (M3 and M4). RESULTS: At least one or more AAbs were detected in 60.3% (47/78) of patients diagnosed with post-COVID syndrome, whereas 37.2% (29/78) of patients were positive for all receptors investigated. Interestingly, a strong correlation has been found between AAbs and pain intensity feeling by the patients measured by Visual Analogic Scale. A significant association was also obtained with insomnia and AABS-positive patients. CONCLUSIONS: The identification of AAbs and their correlation with pathological symptoms seriousness underly the possible role of AAbs as future therapeutic targets.

Serum proteomic profiling reveals potential inflammatory biomarkers in long-COVID patients: a comparative analysis with healthy controls.

OBJECTIVE: The highly transmissible severe acute respiratory syndrome-Coronavirus-2 was responsible for the 2020 COVID-19 pandemic. COVID-19 mostly affects the respiratory system; however, this infection also affects several other organs. In addition, the sequelae of this disease affect patients for several months after recovery, resulting in long-COVID syndrome. PATIENTS AND METHODS: In order to characterize the differences between healthy control individuals and long-COVID patients, proteomic profiling of the serum of both groups was performed by mass spectrometry. The obtained data were analyzed with multivariate and univariate statistical analyses. RESULTS: Initially, performing a partial latent square discriminant analysis (PLS-DA) made it possible to identify thirty-three proteins of interest, which were then subjected to a receiver operating characteristic (ROC) analysis. Four proteins were identified as potential stand-alone biomarkers: Sirtuin 1, Natriuretic Peptide B, Hemopexin, and Arachidonate 5-Lipoxygenase. Moreover, a multivariate ROC analysis identified a panel of biomarkers composed of Natriuretic Peptide B, Anterior Gradient 2 Protein, Adiponectin, Endothelin Converting Enzyme 1, Interferon Induced Transmembrane Protein 1, Mannose Binding Lectin 2, Prostaglandin-Endoperoxide Synthase 2, Pirin, Prostaglandin Reductase 1 and Cystatin C. CONCLUSIONS: The identified biomarkers are associated with inflammatory processes, corroborating literature evidence that long-COVID patients develop an inflammatory state that damages many tissues. Nevertheless, these data should be validated in a larger cohort.