Immune profile of children with post-acute sequelae of SARS-CoV-2 infection (Long Covid) (preprint)

There is increasing reporting by patients organization and researchers of long covid (or post-acute sequelae of SARS-CoV-2 - PASC), characterized by symptoms such as fatigue, dyspnea, chest pain, cognitive and sleeping disturbances, arthralgia and decline in quality of life. Immune system dysregulation with a hyperinflammatory state, direct viral toxicity, endothelial damage and microvascular injury have been proposed as pathologenic mechanisms. Recently, cohorts of children with PASC have been reported in Italy, Sweden and Russia. However, immunological studies of children with PASC have never been performed. In this study, we documented significant immunologic differences between children that completely recovered from acute infection and those with PASC, providing the first objective laboratory sign of the existence of PASC in children.

Serum S100B protein as a marker of severity in Covid-19 patients (preprint)

SARS-CoV-2 infection shows a wide-ranging clinical severity, requiring prognostic markers. We focused on S100B, a calcium-binding protein present in biological fluids, being a reliable biomarker in disorders having inflammatory processes as common basis and RAGE as main receptor. Since Covid-19 is characterized by a potent inflammatory response also involving RAGE, we tested if S100B serum levels were related to disease severity.Serum samples (n=74) were collected from hospitalized SARS-CoV-2 positive patients admitted to Covid center. Illness severity was established by admission clinical criteria and Covid risk score. Treatment protocols followed WHO guidelines available at the time. Circulating S100B was determined by ELISA assay. Statistical analysis used Pearson’s χ2 test, t-Test, and ANOVA, ANCOVA, Linear Regression.S100B was detected in serum from Covid-19 patients, significantly correlating with disease severity as shown both by the level of intensity of care (p<0.006) as well by the value of Covid score (Multiple R-squared: 0.3751); the correlation between Covid-Score and S100B was 0.61 (p<0.01). S100B concentration was associated with inflammation markers (Ferritin, C-Reactive Protein, Procalcitonin), and organ damage markers (Alanine Aminotransferase, Creatinine). Serum S100B plays a role in Covid-19 and can represent a prognostic marker in Sars-CoV-2 infected patients.

A comparison of COVID-19 and imaging radiation risk in clinical patient populations (preprint)

Objective. The outbreak of coronavirus SARS-COV2 disease 2019 (COVID-19) necessitates fast and accurate diagnostic tools. RT-PCR has been identified as gold standard test with Chest-CT and Chest-Radiography showing promising results as well. However, several institutions are discouraging the use of radiological procedures for COVID-19 diagnosis, partly due to radiation risk. This study aimed to provide quantitative data towards an effective risk-to-benefit analysis for the justification of radiological studies in COVID-19 diagnosis to guide policy and decision makers.Methods. The analysis was performed in terms of mortality rate per age group. COVID-19 mortality was extracted from epidemiological data across 159,107 patients in Italy. For radiological risk, the study considered 659 Chest-CT performed in adult patients. Organ doses were estimated using a Monte Carlo method and then used to calculate the Risk Index that was converted into a related 5-year mortality rate (SEER, NCI). Results. COVID-19 mortality showed a rapid rise for ages >30 years old (min:0.30%; max:30.20%), whereas only 1 death was reported in the analyzed patient cohort for ages <20 years old. The rates decreased for radiation risk across age groups. The median mortality rate across all ages for Chest-CT and Chest-Radiography were 0.72% (min:0.46%; max:1.10%) and 0.03% (min:0.02%; max:0.04%), respectively.Conclusions. COVID-19, Chest-Radiography, and Chest-CT mortality rates showed different magnitudes and trends across age groups. In higher ages, COVID-19 risk far outweighs that of radiological exams. Based on risk comparison alone, Chest-Radiography and Chest-CT for COVID-19 care is justified for patients older than 30 and 50 years old, respectively.