Exploring the Role of Immune System and Inflammatory Cytokines in SARS-CoV-2 Induced Lung Disease: A Narrative Review.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative pathogen of coronavirus disease 19 (COVID-19). COVID-19 can manifest with a heterogenous spectrum of disease severity, from mild upper airways infection to severe interstitial pneumonia and devastating acute respiratory distress syndrome (ARDS). SARS-CoV-2 infection may induce an over activation of the immune system and the release of high concentrations of pro-inflammatory cytokines, leading to a "cytokine storm", a recognized pathogenetic mechanism in the genesis of SARS-CoV-2-induced lung disease. This overproduction of inflammatory cytokines has been recognized as a poor prognostic factor, since it can lead to disease progression, organ failure, ARDS and death. Moreover, the immune system shows dysregulated activity, particularly through activated macrophages and T-helper cells and in the co-occurrent exhaustion of lymphocytes. We carried out a non-systematic literature review aimed at providing an overview of the current knowledge on the pathologic mechanisms played by the immune system and the inflammation in the genesis of SARS-CoV-2-induced lung disease. An overview on potential treatments for this harmful condition and for contrasting the "cytokine storm" has also been presented. Finally, a look at the experimented experimental vaccines against SARS-CoV-2 has been included.

Electrophysiological evidence of subclinical trigeminal dysfunction in patients with COVID-19 and smell impairment: A pilot study

Background Smell and taste disturbances are among the most frequent neurological symptoms in patients with COVID-19. A concomitant impairment of the trigeminal nerve has been suggested in subjects with olfactory dysfunction, although it has not been confirmed with objective measurement techniques. In this study, we explored the trigeminal function and its correlations with clinical features in COVID-19 patients with impaired smell perception using electrophysiological testing. Methods We enrolled 16 consecutive patients with mild COVID-19 and smell impairment and 14 healthy controls (HCs). Olfactory and gustatory symptoms were assessed with self-reported questionnaires. Electrophysiological evaluation of the masseter inhibitory reflex (MIR) and blink reflex (BR) was carried out to test the trigeminal function and its connections within the brainstem. Results Masseter inhibitory reflex (MIR) analysis revealed higher latency of ipsilateral and contralateral early silent period in patients when compared with HCs. No significant differences between groups were detected as regards the duration of the early and late silent period. However, several patients showed a prolonged duration of the early silent period. BR evaluation disclosed only an increased amplitude of early components in patients. Conclusions Patients with COVID-19 and smell impairment show a subclinical trigeminal nerve impairment. Trigeminal alterations mainly involve the oligosynaptic pathway, as a result of either direct viral damage or secondary neuroinflammation of the peripheral trigeminal fibers, whereas the polysynaptic ponto-medullary circuits seem to be spared. The prolonged duration of the early silent period and the increased amplitude of early BR response might reflect a compensatory upregulation of the trigeminal function as a consequence of the olfactory dysfunction.

Comparison between Suspected and Confirmed COVID-19 Respiratory Patients: What Is beyond the PCR Test.

COVID-19 modified the healthcare system. Nasal-pharyngeal swab (NPS), with real-time reverse transcriptase-polymerase (PCR), is the gold standard for the diagnosis; however, there are difficulties related to the procedure that may postpone it. The study aims to evaluate whether other elements than the PCR-NPS are reliable and confirm the diagnosis of COVID-19. This is a cross-sectional study on data from the Lung Unit of Pavia (confirmed) and at the Emergency Unit of Palermo (suspected). COVID-19 was confirmed by positive NPS, suspected tested negative. We compared clinical, laboratory and radiological variables and performed Logistic regression to estimate which variables increased the risk of COVID-19. The derived ROC-AUCcurve, assessed the accuracy of the model to distinguish between COVID-19 suspected and confirmed. We selected 50 confirmed and 103 suspected cases. High Reactive C-Protein (OR: 1.02; CI95%: 0.11-1.02), suggestive CT-images (OR: 11.43; CI95%: 3.01-43.3), dyspnea (OR: 10.48; CI95%: 2.08-52.7) and respiratory failure (OR: 5.84; CI95%: 1.73-19.75) increased the risk of COVID-19, whereas pleural effusion decreased the risk (OR: 0.15; CI95%: 0.04-0.63). ROC confirmed the discriminative role of these variables between suspected and confirmed COVID-19 (AUC 0.91). Clinical, laboratory and imaging features predict the diagnosis of COVID-19, independently from the NPS result.

Comparison between Suspected and Confirmed COVID-19 Respiratory Patients: What Is beyond the PCR Test

COVID-19 modified the healthcare system. Nasal-pharyngeal swab (NPS), with real-time reverse transcriptase-polymerase (PCR), is the gold standard for the diagnosis;however, there are difficulties related to the procedure that may postpone it. The study aims to evaluate whether other elements than the PCR-NPS are reliable and confirm the diagnosis of COVID-19. This is a cross-sectional study on data from the Lung Unit of Pavia (confirmed) and at the Emergency Unit of Palermo (suspected). COVID-19 was confirmed by positive NPS, suspected tested negative. We compared clinical, laboratory and radiological variables and performed Logistic regression to estimate which variables increased the risk of COVID-19. The derived ROC-AUCcurve, assessed the accuracy of the model to distinguish between COVID-19 suspected and confirmed. We selected 50 confirmed and 103 suspected cases. High Reactive C-Protein (OR: 1.02;CI95%: 0.11–1.02), suggestive CT-images (OR: 11.43;CI95%: 3.01–43.3), dyspnea (OR: 10.48;CI95%: 2.08–52.7) and respiratory failure (OR: 5.84;CI95%: 1.73–19.75) increased the risk of COVID-19, whereas pleural effusion decreased the risk (OR: 0.15;CI95%: 0.04–0.63). ROC confirmed the discriminative role of these variables between suspected and confirmed COVID-19 (AUC 0.91). Clinical, laboratory and imaging features predict the diagnosis of COVID-19, independently from the NPS result.

Mortality due to COVID-19 during the pandemic: A comparison of first, secondo and third SMAtteo COvid19 REgistry (SMACORE).

COVID-19 tide had shattered on European countries with three distinct and tough waves, from March and April, 2020; October and November, 2020 and March and April, 2021 respectively. We observed a 50% reduction in the hazard of death during both wave II and III compared with wave I (HR 0.54, 95%CI 0.39-0.74 and HR 0.57, 95%CI 0.41-0.80, respectively). Sex and age were independent predictors of death. We compare in-hospital mortality of COVID-19 patients admitted at our Referral Hospital of Northern Italy during the different waves, discuss the reasons of the observed differences and suggest approaches to the challenges ahead.

Psychological Support in a COVID-19 Hospital: A Community Case Study.

Burnout is a well-documented entity in Care Workers population, affecting up to 50% of physicians, just as it is equally well established that managing an infectious disease outbreaks, such as confirmed in the COVID-19 pandemic, increases Post-Traumatic Stress Disorder (PTSD) and the psychological burden. Mental health support, in the form of formal or remote sessions, has been shown to be helpful to health care staff, despite the organizational difficulties in an emergency. During the first emergence of COVID-19 in Italy, the Scientific Institute for Research, Hospitalization and Health Care Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Policlinico San Matteo Foundation (Pavia, Lombardy), the Italian hospital that treated "patient 1," has activated an agreement with the Soleterre Foundation, an international Non-Governmental Organization (NGO) that manages health emergency projects, to provide psychological support. A task force of psychologists was created with the aim of designing and administering a Therapeutic Mental Health Assessment for COVID-19 Care Workers (TMHA COVID-19 CWs) to evaluate and support health care workers' mental health. The assessment battery was developed to evaluate symptoms and behaviors associated with trauma and the corresponding maladaptive behaviors (the National Stressful Events Survey for PTSD-Short Scale "NSESSS" and the Diagnostic and Statistical Manual of Mental Disorders "DSM-5" Self-Rated Level 1 transversal Symptom Measure-Adult). Once the TMHA COVID-19 CWs had been developed, the team of psychologists regularly visited healthcare staff in the ward to administer it. One hundred seven care workers (44 males, mean age 40 ± 15) across Intensive Care Units (ICUs), the emergency room and medical ward were administered the TMHA COVID-19 CWs. PTSD symptoms were reported as severe by 13% of the population. Depressive symptoms as severe for 7% and Anxiety symptoms as severe for 14%. Severe psychotic symptoms were experienced by 2% and severe suicidal thoughts by 1% of the population. The possibility of acting upon the results of the TMHA COVID-19 CWs allowed an early intervention through individual session beyond the cut-off level (moderate and severe symptoms) for PTSD in NSESSS. In fact, 280 individual support sessions were offered. Therefore, we considered our project a protective and support factor for healthcare workers' mental well-being and we recommend implementing a mental health screening program in ward involved in COVID-19 patients' care.

COVID vaccination and asthma exacerbation: might there be a link?

INTRODUCTION: There is ongoing debate regarding the role of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection in asthma exacerbation, and its long-term impact on the lung function of individuals with asthma. In contrast, the potential impact of coronavirus disease 2019 (COVID-19) vaccination on asthma is entirely unexplored. CASE STUDY: This study examined a challenging case of severe asthma exacerbation in a 28-year-old female following two doses of the mRNA-based vaccine BNT162b2 (Pfizer-BioNTech) at IRCCS Policlinico San Matteo in Pavia, Italy. The patient, a fourth-year resident at the hospital, was vaccinated in early 2021. She was an occasional smoker with a 10-year history of asthma and seasonal allergic rhinitis. She tested negative for SARS-CoV-2 on several molecular swabs and serology tests. RESULTS: After receiving the second dose of vaccine, the patient started to experience worsening of respiratory symptoms. Following several episodes and a severe asthma attack, the patient required treatment with mepolizumab, a biologic drug (interleukin-5) antagonist monoclonal antibody. CONCLUSION: This single case study is insufficient to draw conclusions about the association between asthma exacerbation and the COVID-19 vaccine. While the cause-effect link between vaccination against SARS-CoV-2 and worsening of asthmatic disease might only be suggested at present, this case is a valuable prompt for further investigation. This is particularly true from the perspective of mass vaccination of adolescents and children currently underway across the globe.

Impact of Pneumococcal Urinary Antigen Testing in COVID-19 Patients: Outcomes from the San Matteo COVID-19 Registry (SMACORE).

Despite low rates of bacterial co-infections, most COVID-19 patients receive antibiotic therapy. We hypothesized that patients with positive pneumococcal urinary antigens (PUAs) would benefit from antibiotic therapy in terms of clinical outcomes (death, ICU admission, and length of stay). The San Matteo COVID-19 Registry (SMACORE) prospectively enrolls patients admitted for COVID-19 pneumonia at IRCCS Policlinico San Matteo, Pavia. We retrospectively extracted the data of patients tested for PUA from October to December 2020. Demographic, clinical, and laboratory data were recorded. Of 469 patients, 42 tested positive for PUA (8.95%), while 427 (91.05%) tested negative. A positive PUA result had no significant impact on death (HR 0.53 CI [0.22-1.28] p-value 0.16) or ICU admission (HR 0.8; CI [0.25-2.54] p-value 0.70) in the Cox regression model, nor on length of stay in linear regression (estimate 1.71; SE 2.37; p-value 0.47). After adjusting for age, we found no significant correlation between urinary antigen positivity and variations in the WHO ordinal scale and laboratory markers at admission and after 14 days. We found that a positive PUA result was not frequent and had no impact on clinical outcomes or clinical improvement. Our results did not support the routine use of PUA tests to select COVID-19 patients who will benefit from antibiotic therapy.

Do gene-environment interactions play a role in COVID-19 distribution? The case of Alpha-1 Antitrypsin, air pollution and COVID-19.

BACKGROUND: Gene-environment interactions are relevant for several respiratory diseases. This communication raises the hypothesis that the severity of COVID-19, a complex disease where the individual response to the infection may play a significant role, could partly result from a gene-environment interaction between air-pollution and Alpha-1 Antitrypsin (AAT) genes. METHODS: To evaluate the impact of the AAT and air pollution interaction on COVID-19, we introduced an AAT*air pollution global risk score summing together, in each country, an air pollution score (ozone, nitrogen dioxide and fine particulate matter) and an AAT score (which sums the ranked frequency of MZ, SZ, MS). We compared this global score with the ranking of European countries in terms of death number per million persons. RESULTS: The ranking of the AAT*air pollution global risk score matched the ranking of the countries in terms of the observed COVID-19 deaths per 1M inhabitants, namely in the case of the first European countries: Belgium, UK, Spain, Italy, Sweden, France. We observed parallelism between the number of COVID deaths and the AAT*air pollution global risk in Europe. AAT anti-protease, immune-modulating and coagulation-modulating activities may explain this finding, although very speculatively. CONCLUSIONS: Even if further studies taking into account genetic background, population density, temporal dynamics of individual epidemics, access to healthcare, social disparities and immunological response to SARS-CoV2 are needed, our preliminary observation urges to open a discussion on gene-environment interactions in COVID-19.

Mesenchymal Stromal Cell Secretome for Post-COVID-19 Pulmonary Fibrosis: A New Therapy to Treat the Long-Term Lung Sequelae?

To date, more than 100 million people worldwide have recovered from COVID-19. Unfortunately, although the virus is eradicated in such patients, fibrotic irreversible interstitial lung disease (pulmonary fibrosis, PF) is clinically evident. Given the vast numbers of individuals affected, it is urgent to design a strategy to prevent a second wave of late mortality associated with COVID-19 PF as a long-term consequence of such a devastating pandemic. Available antifibrotic therapies, namely nintedanib and pirfenidone, might have a role in attenuating profibrotic pathways in SARS-CoV-2 infection but are not economically sustainable by national health systems and have critical adverse effects. It is our opinion that the mesenchymal stem cell secretome could offer a new therapeutic approach in treating COVID-19 fibrotic lungs through its anti-inflammatory and antifibrotic factors.

Suggestions for lung function testing in the context of COVID-19.

The 2019 coronavirus disease (COVID-19) pandemic is currently a challenge worldwide. Due to the characteristics of lung function tests, the risk of cross infection may be high between health care workers and patients. The role of lung function testing is well defined for the diagnosis of various diseases and conditions. Lung function tests are also indispensable in evaluating the response to medical treatment, in monitoring patient respiratory and systemic pathologies, and in evaluating preoperative risk in cardiothoracic and major abdominal surgeries. However, lung function testing represents a potential route for COVID-19 transmission, due to the aerosol generated during the procedures and the concentration of patients with pulmonary diseases in lung function laboratories. Currently, the opportunities for COVID-19 transmission remain partially unknown, and data are continuously evolving. This review provides useful information on the risks and recommendations for lung function testing, which have varied according to the phase of the pandemic. This information may support national and regional boards and the health authorities to which they belong. There is a need for rapid re-opening of lung function laboratories, but maximum safety is required in the COVID-19 era.

Broncho-alveolar inflammation in COVID-19 patients: a correlation with clinical outcome.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) rapidly reached pandemic proportions. Given that the main target of SARS-CoV-2 are lungs leading to severe pneumonia with hyperactivation of the inflammatory cascade, we conducted a prospective study to assess alveolar inflammatory status in patients with moderate to severe COVID-19. METHODS: Diagnostic bronchoalveolar lavage (BAL) was performed in 33 adult patients with SARS-CoV-2 infection by real-time PCR on nasopharyngeal swab admitted to the Intensive care unit (ICU) (n = 28) and to the Intermediate Medicine Ward (IMW) (n = 5). We analyze the differential cell count, ultrastructure of cells and Interleukin (IL)6, 8 and 10 levels. RESULTS: ICU patients showed a marked increase in neutrophils (1.24 × 105 ml- 1, 0.85-2.07), lower lymphocyte (0.97 × 105 ml- 1, 0.024-0.34) and macrophages fractions (0.43 × 105 ml- 1, 0.34-1.62) compared to IMW patients (0.095 × 105 ml- 1, 0.05-0.73; 0.47 × 105 ml- 1, 0.28-1.01 and 2.14 × 105 ml- 1, 1.17-3.01, respectively) (p < 0.01). Study of ICU patients BAL by electron transmission microscopy showed viral particles inside mononuclear cells confirmed by immunostaining with anti-viral capsid and spike antibodies. IL6 and IL8 were significantly higher in ICU patients than in IMW (IL6 p < 0.01, IL8 p < 0.0001), and also in patients who did not survive (IL6 p < 0.05, IL8 p = 0.05 vs. survivors). IL10 did not show a significant variation between groups. Dividing patients by treatment received, lower BAL concentrations of IL6 were found in patients treated with steroids as compared to those treated with tocilizumab (p < 0.1) or antivirals (p < 0.05). CONCLUSIONS: Alveolitis, associated with COVID-19, is mainly sustained by innate effectors which showed features of extensive activation. The burden of pro-inflammatory cytokines IL6 and IL8 in the broncho-alveolar environment is associated with clinical outcome.

Venous thromboembolism and COVID-19: a single center experience from an academic tertiary referral hospital of Northern Italy.

Preliminary evidence supports the notion that COVID-19 patients may have an increased susceptibility to develop venous thromboembolism (VTE). However, the magnitude of this association still needs to be defined. Furthermore, clinical predictors of thrombogenesis, and the relationship with the inflammatory status are currently unknown. On this basis, we conducted a retrospective, observational study on 259 consecutive COVID-19 patients admitted to an academic tertiary referral hospital in Northern Italy between March 19th and April 6th, 2020. Records of COVID-19 patients with a definite VTE event were reviewed for demographic information, co-morbidities, risk factors for VTE, laboratory tests, and anticoagulation treatment. Twenty-five cases among 259 COVID-19 patients developed VTE (9.6%), all of them having a Padua score > 4, although being under standard anticoagulation prophylaxis since hospital admission. In the VTE subcohort, we found a significant positive correlation between platelet count (PLT) and either C reactive protein (CRP) (p < 0.0001) or lactate dehydrogenase (LDH) (p = 0.0013), while a significant inverse correlation was observed between PLT and mean platelet volume (p < 0.0001). Platelet-to-lymphocyte ratio significantly correlated with CRP (p < 0.0001). The majority of VTE patients was male and younger compared to non-VTE patients (p = 0.002 and p = 0.005, respectively). No significant difference was found in D-dimer levels between VTE and non VTE patients, while significantly higher levels of LDH (p = 0.04) and IL-6 (p = 0.04) were observed in VTE patients in comparison to non-VTE patients. In conclusion, our findings showed a quite high prevalence of VTE in COVID-19 patients. Raised inflammatory indexes and increased serum levels of pro-inflammatory cytokines should raise the clinical suspicion of VTE.

Comorbidities, Cardiovascular Therapies, and COVID-19 Mortality: A Nationwide, Italian Observational Study (ItaliCO).

Background: Italy has one of the world's oldest populations, and suffered one the highest death tolls from Coronavirus disease 2019 (COVID-19) worldwide. Older people with cardiovascular diseases (CVDs), and in particular hypertension, are at higher risk of hospitalization and death for COVID-19. Whether hypertension medications may increase the risk for death in older COVID 19 inpatients at the highest risk for the disease is currently unknown. Methods: Data from 5,625 COVID-19 inpatients were manually extracted from medical charts from 61 hospitals across Italy. From the initial 5,625 patients, 3,179 were included in the study as they were either discharged or deceased at the time of the data analysis. Primary outcome was inpatient death or recovery. Mixed effects logistic regression models were adjusted for sex, age, and number of comorbidities, with a random effect for site. Results: A large proportion of participating inpatients were ≥65 years old (58%), male (68%), non-smokers (93%) with comorbidities (66%). Each additional comorbidity increased the risk of death by 35% [adjOR = 1.35 (1.2, 1.5) p < 0.001]. Use of ACE inhibitors, ARBs, beta-blockers or Ca-antagonists was not associated with significantly increased risk of death. There was a marginal negative association between ARB use and death, and a marginal positive association between diuretic use and death. Conclusions: This Italian nationwide observational study of COVID-19 inpatients, the majority of which ≥65 years old, indicates that there is a linear direct relationship between the number of comorbidities and the risk of death. Among CVDs, hypertension and pre-existing cardiomyopathy were significantly associated with risk of death. The use of hypertension medications reported to be safe in younger cohorts, do not contribute significantly to increased COVID-19 related deaths in an older population that suffered one of the highest death tolls worldwide.