Impact of Innate Immunity, Endothelial Damage, and Metabolic Biomarkers on COVID-19 Severity and Mortality.

In this study, abnormal levels of myeloid activation, endothelial damage, and innate immune markers were associated with severe coronavirus disease 2019 (COVID-19), while higher levels of metabolic biomarkers (irisin, leptin) demonstrated a protective effect. These data support a model for COVID-19 immunopathogenesis linking robust inflammation and endothelial damage in metabolically predisposed individuals.

Impact of innate immunity, endothelial damage, and metabolic biomarkers on COVID-19 severity and mortality

In this study, abnormal levels of myeloid activation, endothelial damage and innate immune markers were associated with severe COVID-19, while higher levels of metabolic biomarkers (irisin, leptin), demonstrated a protective effect. These data support a model for COVID-19 immunopathogenesis linking robust inflammation and endothelial damage in metabolically-predisposed individuals.

Increased SARS-CoV-2 seroprevalence in healthy blood donors after the second pandemic wave in South-Eastern Italy: evidence for asymptomatic young donors as potential virus spreaders.

BACKGROUND: Italy experienced SARS-CoV-2 spread during the second wave and the southern regions were severely affected. In this prospective study, we assessed the changes in SARS-CoV-2 seroprevalence rates in non-vaccinated blood donors to evaluate the spread of SARS-CoV-2 among healthy individuals in our geographical area. METHODS: 8,183 healthy blood donors visiting the Transfusion Centre at the University Hospital "Riuniti" of Foggia (Italy) to donate blood from May 2020 to March 2021 were tested twice for anti-SARS-CoV-2 antibodies by Ortho Clinical Diagnostics VITROS® 3600 through anti-SARS-CoV-2 Total and IgG reagent kit. None of the subjects had diagnosed symptomatic COVID-19 infection, and none had received vaccination. RESULTS: Overall, 516 out of 8,183 had antibodies to SARS-CoV-2 (total and IgG antibodies) (6.3%, 95% CI: 0.03-0.15%), 387 were male and 129 female. There was a significant increase of seropositive donors from May 2020 to March 2021 (p < .001). The difference in seroprevalence was significantly associated with age but not sex (2-sided p < .05 for age; 2-sided p ≥ .05 for sex) in both groups. CONCLUSIONS: Our study showed a significant increase in SARS-CoV-2 seroprevalence in blood donors and suggests that asymptomatic individuals might contribute to the spread of SARS-CoV-2. These results may contribute to revised containment measures, priorities in vaccine campaigns and monitoring of seroprevalence in public places like Transfusion Centres. Serologic testing of blood donors may be relevant to monitor SARS-CoV-2 circulation in the general population.

Guillain-Barré syndrome as only manifestation of COVID-19 infection.

Post-infectious/immune mediated effects of COVID-19 infection include descriptions of Guillain-Barré syndrome (GBS) in patients usually with respiratory failure and after 1-2 weeks from the onset of viral illness. Asymptomatic cases for COVID-19 infection were rarely described. Herein, we studied a 62-year-old patient with progressive weakness of lower extremities, rapidly evolving to a severe, flaccid tetraplegia and dysphagia. Neurological symptoms weren't preceded by fever or pulmonary symptoms. Because of laboratory test abnormalities (thrombocytopenia, lymphocytopenia, high inflammation indexes), the patient underwent to nasopharyngeal swab, resulted positive for SARS-CoV-2 on RT-PCR assay; cerebrospinal fluid (CSF) was negative for SARS-CoV-2. The clinical (severe symmetric distal upper and lower limbs weakness, grade 0/5; decreased proprioceptive sensitivity and hypoesthesia involving the four limbs; loss of deep tendon reflexes), electrophysiological (prevailing axonal polyradiculoneuritis) and CSF features (albumino-cytological dissociation) disclosed the GBS diagnosis (level 1 of diagnostic certainty according to the Brighton criteria). The patient received plasma exchange and immunoglobulin, and, at 4 weeks after treatment and physical therapy, the patient had moderate improvement (weakness at lower and upper extremities was grade 2/5 and 3/5, respectively). Neurologists and clinicians should be aware of the possible link between neurological symptoms and COVID-19 infection, not only after viral prodrome and pulmonary symptoms, but also without COVID-19 symptoms.

Results from a survey in healthy blood donors in South Eastern Italy indicate that we are far away from herd immunity to SARS-CoV-2.

Here we present results from a survey on anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) seroprevalence in healthy blood donors from a low incidence coronavirus disease 2019 area (Apulia region, South Eastern Italy). Among 904 subjects tested, only in nine cases (0.99%) antibodies against SARS-CoV-2 were demonstrated. All the nine seropositive patients were negative for the research of viral RNA by reverse transcription polymerase chain reaction in nasopharyngeal swabs. These data, along with those recently reported from other countries, clearly show that we are very far from herd immunity and that the containment measures are at the moment the only realistic instrument we have to slow the spread of the pandemic.

Low Prevalence of Antibodies to SARS-CoV-2 and Undetectable Viral Load in Seropositive Blood Donors from South-Eastern Italy.

Recently, a significant cluster of pneumonia caused by a novel betacoronavirus (severe acute respiratory syndrome coronavirus 2, SARS-CoV-2) was described initially in China and then spread throughout the world. Like other coronaviridae, the viral transmission occurs mainly through droplets. In addition, the virus has been detected in different clinical specimens, suggesting a potential transmission by other routes, including blood transfusion. However, the potential risk of transmission of SARS-CoV-2 via blood products is still unclear. The aim of our study was to investigate the prevalence of antibodies against SARS-CoV-2 among blood donors from South-Eastern Italy. Moreover, in the seropositive donors, we searched for the presence of the virus in nasopharyngeal swabs and in plasma samples. Overall, 1,797 blood donors from the Apulia region were tested for anti-SARS-CoV-2 antibodies, using a commercially available assay. Only 18/1,797 donors (1.0%) tested positive for anti-SARS-CoV-2 antibodies; in none of them SARS-CoV-2 viral RNA was detected in nasopharyngeal swabs and in plasma samples. Our results indicate that most of the blood donors in Apulia remained uninfected during this wave of the pandemic; further, none had detectable virus both in nasopharyngeal swabs and in blood samples. The risk to carry and transmit the virus by healthy and asymptomatic blood donors is probably very low.