COVID-19 Biomarkers at the Crossroad between Patient Stratification and Targeted Therapy: The Role of Validated and Proposed Parameters

Vitamin D Supplementation in Neonatal and Infant MIS-C Following COVID-19 Infection

To date, the SARS-CoV-2 pandemic still represents a great clinical challenge worldwide, and effective anti-COVID-19 drugs are limited. For this reason, nutritional supplements have been investigated as adjuvant therapeutic approaches in disease management. Among such supplements, vitamin D has gained great interest, due to its immunomodulatory and anti-inflammatory actions both in adult and pediatric populations. Even if there is conflicting evidence about its prevention and/or mitigation effectiveness in SARS-CoV-2 infection, several studies demonstrated a strict correlation between hypovitaminosis D and disease severity in acute COVID-19 and MIS-C (multisystem inflammatory syndrome in children). This narrative review offers a resume of the state of the art about vitamin D's role in immunity and its clinical use in the context of the current pandemic, specially focusing on pediatric manifestations and MIS-C. It seems biologically reasonable that interventions aimed at normalizing circulating vitamin D levels could be beneficial. To help clinicians in establishing the correct prophylaxis and/or supportive therapy with vitamin D, well-designed and adequately statistically powered clinical trials involving both adult and pediatric populations are needed. Moreover, this review will also discuss the few other nutraceuticals evaluated in this context.

Efficacy of sotrovimab on omicron BA.2, BA.4 and BA.5 subvariants of sars-cov-2 vs. other early therapies: a systematic review and meta-analysis of literature data

Background

The aim of this meta-analysis was to ascertain whether sotrovimab was effective in reducing COVID-19 related hospitalization and mortality also in Omicron BA.2, BA.4 and BA.5 subvariants compared to other antivirals effective in index period.

Methods

A systematic review and meta-analysis of Randomized Controlled Trials (RCTs) and observational studies comparing the efficacy of early treatment with sotrovimab compared to other early treatment effective in index period, antivirals or monoclonal antibodies (mAbs), in patients with COVID-19 during BA.2, BA.4, BA.5 waves, conducted in accordance with PRISMA guidelines. We searched MEDLINE, Google Scholar and the Cochrane Library. Mortality and hospitalization were defined as outcomes.

Results

Four studies were included, allowing a meta-analysis of 8,041 patients. Meta-analysis showed no statistical difference between groups in hospitalization and mortality. Precisely, the RR of mortality showed no difference in the sotrovimab group compared to treatment with other drugs (OR 0.38, 95% CI 0.10-1.49, p<0.166). As regards the rate of hospitalization, no significant difference resulted between the patients treated with sotrovimab and those with other drugs (OR 1.66, 95% CI 0.41-6.66, p=0.477).

Interpretation

In conclusion, this meta-analysis showed no significant difference between sotrovimab or other antivirals in reducing COVID-19 evolution in patients with a high risk of progression, considering both hospitalization and mortality.

Developing a Tool for Differentiation Between Bacterial and Viral Respiratory Infections Using Myxovirus Resistance Protein A and C-Reactive Protein

INTRODUCTION

The aim was to assess the performance of a blood assay combining measurements of MxA (myxovirus resistance protein A) and CRP (C-reactive protein) to differentiate viral from bacterial respiratory infections.

METHODS

In a prospective study, MxA and CRP were measured in the blood by the AFIAS panel in adults admitted with respiratory infection. Patients were split into discovery and validation cohorts. Final diagnosis was adjudicated by a panel of experts. Microbiology-confirmed cases comprised the discovery cohort, and infections adjudicated as highly probable viral or bacterial comprised the validation cohort.

RESULTS

A total of 537 patients were analyzed: 136 patients were adjudicated with definitive viral infections and 131 patients with definitive bacterial infections. Using logistic regression analysis, an equation was developed to calculate the probability for bacterial infection using the absolute value of MxA and CRP. Calculated probability ≥ 0.5 and/or MxA to CRP ratio less than 2 applied as the diagnostic rule for bacterial infections. This rule provided 91.6% sensitivity and 90.4% negative predictive value for the diagnosis of bacterial infections. This diagnostic sensitivity was confirmed in the validation cohort. A MxA/CRP ratio less than 0.15 was associated with unfavorable outcome.

CONCLUSION

The calculation of the probability for bacterial infection using MxA and CRP may efficiently discriminate between viral and bacterial respiratory infections.

Preliminary Comparison of Molecular Antioxidant and Inflammatory Mechanisms Determined in the Peripheral Blood Granulocytes of COVID-19 Patients

The aim of this study was to evaluate selected parameters of redox signaling and inflammation in the granulocytes of COVID-19 patients who recovered and those who died. Upon admission, the patients did not differ in terms of any relevant clinical parameter apart from the percentage of granulocytes, which was 6% higher on average in those patients who died. Granulocytes were isolated from the blood of 15 healthy people and survivors and 15 patients who died within a week, and who were selected post hoc for analysis according to their matching gender and age. They differed only in the lethal outcome, which could not be predicted upon arrival at the hospital. The proteins level (respective ELISA), antioxidant activity (spectrophotometry), and lipid mediators (UPUPLC-MS) were measured in the peripheral blood granulocytes obtained via gradient centrifugation. The levels of Nrf2, HO-1, NFκB, and IL-6 were higher in the granulocytes of COVID-19 patients who died within a week, while the activity of cytoplasmic Cu,Zn-SOD and mitochondrial Mn-SOD and IL-2/IL-10 were lower in comparison to the levels observed in survivors. Furthermore, in the granulocytes of those patients who died, an increase in pro-inflammatory eicosanoids (PGE2 and TXB2), together with elevated cannabinoid receptors 1 and 2 (associated with a decrease in the anti-inflammatory 15d-PGJ2), were found. Hence, this study suggests that by triggering transcription factors, granulocytes activate inflammatory and redox signaling, leading to the production of pro-inflammatory eicosanoids while reducing cellular antioxidant capacity through SOD, thus expressing an altered response to COVID-19, which may result in the onset of systemic oxidative stress, ARDS, and the death of the patient.