A Focus on the Pathophysiology of Adrenomedullin Expression: Endothelitis and Organ Damage in Severe Viral and Bacterial Infections.

Adrenomedullin (ADM) is a peptide hormone produced primarily in the adrenal glands, playing a crucial role in various physiological processes. As well as improving vascular integrity and decreasing vascular permeability, ADM acts as a vasodilator, positive inotrope, diuretic, natriuretic and bronchodilator, antagonizing angiotensin II by inhibiting aldosterone secretion. ADM also has antihypertrophic, anti-apoptotic, antifibrotic, antioxidant, angiogenic and immunoregulatory effects and antimicrobial properties. ADM expression is upregulated by hypoxia, inflammation-inducing cytokines, viral or bacterial substances, strength of shear stress, and leakage of blood vessels. These pathological conditions are established during systemic inflammation that can result from infections, surgery, trauma/accidents or burns. The ability to rapidly identify infections and the prognostic, predictive power makes it a valuable tool in severe viral and bacterial infections burdened by high incidence and mortality. This review sheds light on the pathophysiological processes that in severe viral or bacterial infections cause endothelitis up to the development of organ damage, the resulting increase in ADM levels dosed through its more stable peptide mid-regional proadrenomedullin (MR-proADM), the most significant studies that attest to its diagnostic and prognostic accuracy in highlighting the severity of viral or bacterial infections and appropriate therapeutic insights.

Prediction of new-onset atrial fibrillation with the C2HEST score in patients admitted with community-acquired pneumonia.

PURPOSE: Patients hospitalized for community-acquired pneumonia (CAP) may have a higher risk of new-onset atrial fibrillation (NOAF). The C2HEST score was developed to evaluate the NOAF risk in the general population. Data on the value of the C2HEST score in acute patients admitted with CAP are lacking. We want to establish the predictive value of C2HEST score for NOAF in patients with CAP. METHODS: Patients with CAP enrolled in the SIXTUS cohort were enrolled. C2HEST score was calculated at baseline. In-hospital NOAF was recorded. Receiver-operating Characteristic (ROC) curve and multivariable Cox proportional hazard regression analysis were performed. RESULTS: We enrolled 473 patients (36% women, mean age 70.6 ± 16.5 years), and 54 NOAF occurred. Patients with NOAF were elderly, more frequently affected by hypertension, heart failure, previous stroke/transient ischemic attack, peripheral artery disease and hyperthyroidism. NOAF patients had also higher CURB-65, PSI class and CHA2DS2-VASc score. The C-index of C2HEST score for NOAF was 0.747 (95% confidence interval [95%CI] 0.705-0.786), higher compared to CURB-65 (0.611, 95%CI 0.566-0.655, p = 0.0016), PSI (0.665, 95%CI 0.621-0.708, p = 0.0199) and CHA2DS2-VASc score (0.696, 95%CI 0.652-0.737, p = 0.0762). The best combination of sensitivity (67%) and specificity (70%) was observed with a C2HEST score ≥ 4. This result was confirmed by the multivariable Cox analysis (Hazard Ratio [HR] for C2HEST score ≥ 4 was 10.7, 95%CI 2.0-57.9; p = 0.006), independently from the severity of pneumonia. CONCLUSION: The C2HEST score was a useful predictive tool to identify patients at higher risk for NOAF during hospitalization for CAP. CLINICAL TRIAL REGISTRATION: www. CLINICALTRIALS: gov (NCT01773863).

NOX2 as a Biomarker of Academic Performance: Evidence from University Students during Examination.

BACKGROUND: Cortisol levels, oxidative stress, and lower cerebral performance seem to be closely related. This study aimed to evaluate the question of whether exam stress affected oxidative stress and endothelial function parameters in the salivary samples of students. METHODS: A total of 114 healthy students were recruited. All students were subjected to a 21-item DASS questionnaire to assess perceived stress. Cortisol levels, biomarkers of oxidative stress, and endothelial function were evaluated at T0, during the semester, and T1, in the morning before the exam, in saliva samples. In vitro, HUVECs were stimulated with cortisol, and oxidative stress and endothelial function parameters were evaluated. RESULTS: At T1, cortisol levels were significantly increased compared with the levels during the semester. Moreover, exam results correlated inversely with the DASS score at T1. In addition, NOX2, H2O2 and endothelin-1 significantly increased, while NO bioavailability decreased. In vitro, HUVECs treatment with human cortisol determined the increase of oxidative stress and the decrease of endothelial function, in association with impaired eNOS phosphorylation. CONCLUSION: NOX2-mediated oxidative stress is a mechanism that could mediate cortisol-induced transient endothelial dysfunction during academic examination. Therefore, strategies to monitor or modulate oxidative stress could help students to reduce the impact of examination-related stress.

Hypoalbuminemia as predictor of thrombotic events in patients with community-acquired pneumonia.

BACKGROUND: Hypoalbuminemia complicates acute diseases and infections and is associated with a worst prognosis. The aim is to evaluate whether hypoalbuminemia is associated with higher incidence and risk of thrombotic events in community-acquired pneumonia. METHODS: We retrospectively collected data from a prospective study investigating the incidence of thrombotic events in community-acquired pneumonia hospitalized patients from 2011 to 2016 at University-Hospital Policlinico Umberto I. Baseline characteristics and outcomes were collected. Incidence of outcomes were calculated. Kaplan-Meier curves were created, Cox model used to identify predictors for the outcomes, and competing risk analysis performed. RESULTS: From a total of 231 patients, 130 (56.3%) and 101 (43.7%) had or not hypoalbuminemia. Age, proportion of female, BMI, major comorbidities, and severity of pneumonia were similar between two subgroups. A less proportion of patients with hypoalbuminemia received antithrombotic and statin therapy. Median hospital stay was 11 days in both subgroups. Patients with hypoalbuminemia had higher D-dimer and high- sensitivity C-reactive-protein values with an inverse relation between albumin values and these markers. Incidence of thrombotic events was 26 and 11 per 1000 patient-days in patient with and without hypoalbuminemia. At Cox model, hypoalbuminemia was associated with thrombotic events development in univariable (hazard ratio; 2.67, 95% confidence intervals, 1.30-5.40) and multivariable (hazard ratio 3.19; 95% confidence intervals, 1.48-6.89) analysis. CONCLUSIONS: More than a half of patients with community acquired pneumonia had hypoalbuminemia that is associated with a doubled incidence and a three-fold increased risk of thrombotic events. The inverse relation between baseline albumin and D-dimer values confirms this association.

Low-grade endotoxemia is associated with cardiovascular events in community-acquired pneumonia.

OBJECTIVES: Community-acquired pneumonia (CAP) is associated with low-grade endotoxemia but its relationship with cardiovascular events (CVE) has not been investigated. METHODS: We evaluated the incidence of CVE including myocardial infarction, stroke, and cardiovascular death in 523 adult patients hospitalized for CAP. Serum lipopolysaccharide (LPS) and zonulin, a marker of gut permeability, were analyzed in the cohort, that was followed-up during hospitalization and up to 43 months thereafter. RESULTS: During the hospital-stay, 55 patients experienced CVE with a progressive increase from the lowest (0.6%) to highest LPS tertile (23.6%, p < 0.001). Logistic regression analyses showed that higher LPS tertile was independently associated with CVE; LPS significantly correlated with age, hs-CRP and zonulin. In a sub-group of 23 CAP patients, blood E. coli DNA was higher in patients compared to 24 controls and correlated with LPS. During the long-term follow-up, 102 new CVE were registered; the highest tertile of LPS levels was associated with incident CVE; Cox regression analysis showed that LPS tertiles, age, history of CHD, and diabetes independently predicted CVE. CONCLUSIONS: In CAP low-grade endotoxemia is associated to short- and long-term risk of CVE. Further study is necessary to assess if lowering LPS by non-absorbable antibiotics may result in improved outcomes.

Mid-Regional Pro-Adrenomedullin Can Predict Organ Failure and Prognosis in Sepsis?

Sepsis causes immune dysregulation and endotheliitis, with an increase in mid-regional pro-adrenomedullin (MR-proADM). The aim of the study is to determine an MR-proADM value that, in addition to clinical diagnosis, can identify patients with localized infection or those with sepsis/septic shock, with specific organ damage or with the need for intensive care unit (ICU) transfer and prognosis. The secondary aim is to correlate the MR-proADM value with the length of stay (LOS). In total, 301 subjects with sepsis (124/301 with septic shock) and 126 with localized infection were retrospectively included. In sepsis, MR-proADM ≥ 3.39 ng/mL identified acute kidney injury (AKI); ≥2.99 ng/mL acute respiratory distress syndrome (ARDS); ≥2.28 ng/mL acute heart failure (AHF); ≥2.55 ng/mL Glascow Coma Scale (GCS) < 15; ≥3.38 multi-organ involvement; ≥3.33 need for ICU transfer; ≥2.0 Sequential Organ Failure Assessment (SOFA) score ≥ 2; and ≥3.15 ng/mL non-survivors. The multivariate analysis showed that MR-proADM ≥ 2 ng/mL correlates with AKI, anemia and SOFA score ≥ 2, and MR-proADM ≥ 3 ng/mL correlates with AKI, GCS < 15 and SOFA score ≥ 2. A correlation between mortality and AKI, GCS < 15, ICU transfer and cathecolamine administration was found. In localized infection, MR-proADM at admission ≥ 1.44 ng/mL identified patients with AKI; ≥1.0 ng/mL with AHF; and ≥1.44 ng/mL with anemia and SOFA score ≥ 2. In the multivariate analysis, MR-proADM ≥ 1.44 ng/mL correlated with AKI, anemia, SOFA score ≥ 2 and AHF. MR-proADM is a marker of oxidative stress due to an infection, reflecting severity proportionally to organ damage.

Mid-Regional Pro-Adrenomedullin and N-Terminal Pro-B-Type Natriuretic Peptide Measurement: A Multimarker Approach to Diagnosis and Prognosis in Acute Heart Failure.

BACKGROUND: Acute heart failure (AHF) is a major cause of hospitalization and mortality worldwide. Early and accurate diagnosis, as well as effective risk stratification, are essential for optimizing clinical management and improving patient outcomes. In this context, biomarkers have gained increasing interest in recent years as they can provide important diagnostic and prognostic information in patients with AHF. AIM AND METHODS: The primary objective of the present study was to compare the levels of N-terminal pro-B-type natriuretic peptide (NT-proBNP), mid-regional pro-adrenomedullin (MR-proADM), and C-reactive protein (CRP) between patients diagnosed with acute heart failure (AHF) and those without AHF and sepsis. Furthermore, the study aimed to assess the diagnostic and prognostic value of the use of a multimarker approach in AHF patients. To achieve these objectives, a total of 145 patients with AHF and 127 patients without AHF and sepsis, serving as the control group, were consecutively enrolled in the study. RESULTS: Levels of MR-proADM (median: 2.07; (25th-75th percentiles: 1.40-3.02) vs. 1.11 (0.83-1.71) nmol/L, p < 0.0001), and NT-proBNP (5319 (1691-11,874) vs. 271 (89-931.5) pg/mL, p < 0.0001) were significantly higher in patients with AHF compared to controls, whereas CRP levels did not show significant differences. The mortality rate in the AHF group during in-hospital stay was 12%, and the rate of new re-admission for AHF within 30 days after discharge was 10%. During in-hospital follow-up, Cox regression analyses showed that levels of NT-proBNP > 10,132 pg/mL (hazard ratio (HR) 2.97; 95% confidence interval (CI): 1.13-7.82; p = 0.0284) and levels of MR-proADM > 2.8 nmol/L (HR: 8.57; CI: 2.42-30.28; p = 0.0009) predicted mortality. The combined use of MR-proADM and NT-proBNP provided significant additive predictive value for mortality and new re-admission for AHF at 30 days after discharge. A logistic regression analysis showed that the presence of NT-proBNP pg/mL > 12,973 pg mL and/or MR-proADM > 4.2 nmol/L predicted hospital re-admission within 30 days (OR: 3.23; CI: 1.05-9.91; p = 0.041). CONCLUSION: The combined assay of MR-proADM and NT-proBNP could be helpful in accurately identifying AHF and in defining prognosis and re-admission for AHF. The complementary use of these biomarkers can provide a useful clinical evaluation of AHF while also orienting clinicians to the pathophysiology underlying heart damage and assisting them in tailoring therapy.

Adherence to the Mediterranean Diet in Preventing Major Cardiovascular Events in Patients with Ischemic Heart Disease: The EVA Study.

BACKGROUND: Adherence to healthy dietary patterns, such as the Mediterranean diet (Med-diet), is recommended for the maintenance of cardiovascular health. The determinants for adherence to Med-diet and its importance in secondary cardiovascular disease prevention are still unclear. The aim of the study was to evaluate the influence of sex- and psycho-socio-cultural (i.e., gender-related) factors on Med-diet adherence and its role in preventing major cardiovascular events (MACEs) in patients with ischemic heart disease (IHD). METHODS: Med-diet adherence was evaluated among 503 consecutive adults with IHD. MACEs were collected during a long-term follow-up. RESULTS: Male Bem Sex-Role Inventory score (i.e., male personality traits) and physical functional capacity were associated with higher adherence, while cohabitation with a smoker and physical inactivity with poorer adherence. During a median follow-up of 22 months, 48 participants experienced MACEs (17.5%, 8.1%, and 3.9% of patients with low, medium, and high adherence, respectively; p = 0.016). At multivariate Cox--regression analysis, a greater adherence remained inversely associated with MACEs (HR: 0.49; 95% CI: 0.29-0.82; p = 0.006) after adjusting for confounding factors. CONCLUSION: The study suggests that gender-related factors have a role in maintaining a healthy dietary pattern. Improving Med-diet adherence may lower the risk of recurring cardiovascular events.

Endothelial dysfunction, oxidative stress and low-grade endotoxemia in COVID-19 patients hospitalised in medical wards.

BACKGROUND: Endothelial dysfunction, assessed by flow-mediated dilation (FMD), is related to poor prognosis in patients with COVID-19 pneumonia (CP). In this study, we explored the interplay among FMD, NADPH oxidase type 2 (NOX-2) and lipopolysaccharides (LPS) in hospitalised patients with CP, community acquired pneumonia (CAP) and controls (CT). METHODS: We enrolled 20 consecutive patients with CP, 20 hospitalised patients with CAP and 20 CT matched for sex, age, and main cardiovascular risk factors. In all subjects we performed FMD and collected blood samples to analyse markers of oxidative stress (soluble Nox2-derived peptide (sNOX2-dp), hydrogen peroxide breakdown activity (HBA), nitric oxide (NO), hydrogen peroxide (H2O2)), inflammation (TNF-α and IL-6), LPS and zonulin levels. RESULTS: Compared with controls, CP had significant higher values of LPS, sNOX-2-dp, H2O2,TNF-α, IL-6 and zonulin; conversely FMD, HBA and NO bioavailability were significantly lower in CP. Compared to CAP patients, CP had significantly higher levels of sNOX2-dp, H2O2, TNF-α, IL-6, LPS, zonulin and lower HBA. Simple linear regression analysis showed that FMD inversely correlated with sNOX2-dp, H2O2, TNF-α, IL-6, LPS and zonulin; conversely FMD was directly correlated with NO bioavailability and HBA. Multiple linear regression analysis highlighted LPS as the only predictor of FMD. CONCLUSION: This study shows that patients with COVID-19 have low-grade endotoxemia that could activate NOX-2, generating increased oxidative stress and endothelial dysfunction.

A machine-learning based bio-psycho-social model for the prediction of non-obstructive and obstructive coronary artery disease.

BACKGROUND: Mechanisms of myocardial ischemia in obstructive and non-obstructive coronary artery disease (CAD), and the interplay between clinical, functional, biological and psycho-social features, are still far to be fully elucidated. OBJECTIVES: To develop a machine-learning (ML) model for the supervised prediction of obstructive versus non-obstructive CAD. METHODS: From the EVA study, we analysed adults hospitalized for IHD undergoing conventional coronary angiography (CCA). Non-obstructive CAD was defined by a stenosis < 50% in one or more vessels. Baseline clinical and psycho-socio-cultural characteristics were used for computing a Rockwood and Mitnitski frailty index, and a gender score according to GENESIS-PRAXY methodology. Serum concentration of inflammatory cytokines was measured with a multiplex flow cytometry assay. Through an XGBoost classifier combined with an explainable artificial intelligence tool (SHAP), we identified the most influential features in discriminating obstructive versus non-obstructive CAD. RESULTS: Among the overall EVA cohort (n = 509), 311 individuals (mean age 67 ± 11 years, 38% females; 67% obstructive CAD) with complete data were analysed. The ML-based model (83% accuracy and 87% precision) showed that while obstructive CAD was associated with higher frailty index, older age and a cytokine signature characterized by IL-1ß, IL-12p70 and IL-33, non-obstructive CAD was associated with a higher gender score (i.e., social characteristics traditionally ascribed to women) and with a cytokine signature characterized by IL-18, IL-8, IL-23. CONCLUSIONS: Integrating clinical, biological, and psycho-social features, we have optimized a sex- and gender-unbiased model that discriminates obstructive and non-obstructive CAD. Further mechanistic studies will shed light on the biological plausibility of these associations. CLINICAL TRIAL REGISTRATION: NCT02737982.

Distinct platelet crosstalk with adaptive and innate immune cells after adenoviral and mRNA vaccination against SARS-CoV-2.

BACKGROUND: Genetic-based COVID-19 vaccines have proved to be highly effective in reducing the risk of hospitalization and death. Because they were first distributed in a large-scale population, the adenoviral-based vaccines were linked to a very rare thrombosis with thrombocytopenia syndrome, and the interplay between platelets and vaccinations increasingly gained attention. OBJECTIVES: The objective of this article was to study the crosstalk between platelets and the vaccine-induced immune response. METHODS: We prospectively enrolled young healthy volunteers who received the mRNA-based vaccine, BNT162b2 (n = 15), or the adenovirus-based vaccine, AZD1222 (n = 25) and studied their short-term platelet and immune response before and after vaccine injections. In a separate cohort, we retrospectively analyzed the effect of aspirin on the antibody response 1 and 5 months after BNT162b2 vaccination. RESULTS: Here, we show that a faster antibody response to either vaccine is associated with the formation of platelet aggregates with marginal zone-like B cells, a subset geared to bridge the temporal gap between innate and adaptive immunities. However, although the mRNA-based vaccine is associated with a more gradual and tolerogenic response that fosters the crosstalk between platelets and adaptive immunity, the adenovirus-based vaccine, the less immunogenic of the 2, evokes an antiviral-like response during which the platelets are cleared and less likely to cooperate with B cells. Moreover, subjects taking aspirin (n = 56) display lower antibody levels after BNT162b2 vaccination compared with matched individuals. CONCLUSION: Platelets are a component of the innate immune pathways that promote the B-cell response after vaccination. Future studies on the platelet-immune crosstalk post-immunization will improve the safety, efficacy, and strategic administration of next-generation vaccines.

Association between PaO2/FiO2 ratio and thrombotic events in COVID-19 patients.

PaO2/FiO2 (P/F ratio) is considered a marker of hypoxia/hypoxemia and mortality. Several prothrombotic changes are associated with the decrease of P/F ratio. The role of P/F ratio in patients with arterial and venous thrombosis remains unclear. The aim of this study was to assess in patients with coronavirus disease 2019 (COVID-19), the association between P/F ratio and arterial/venous thrombosis. One thousand and four hundred and six COVID-19 patients were recruited; 289 (21%) patients had P/F ratio < 200 and 1117 (79%) ≥ 200. Compared to the patients with P/F ratio ≥ 200, those with P/F ratio < 200 were older and with higher levels of glycemia, D-dimer and lower levels of albumin. Multiple linear regression analysis showed that albumin (standardized coefficient ß:  0.156; SE: 0.001; p = 0.0001) and D-dimer (standardized coefficient ß: -0.135; SE: 0.0001; p = 0.0001) were associated with P/F ratio. During the hospitalization 159 patients were transferred in intensive care unit (ICU), 253 patients died, 156 patients had arterial or venous thrombotic events. A bivariate logistic analysis was performed to analyze the predictors of thrombosis in COVID-19 patients; P/F ratio < 200 (Odds Ratio: [OR] 1.718, 95% Confidence Interval [CI] 1.085-2.718, p = 0.021), albumin (OR 1.693, 95% CI 1.055-2.716, p = 0.029), D-dimer (OR 3.469, 95% CI 2.110-5.703, p < 0.0001), coronary artery disease (CAD) (OR 1.800, 95% CI 1.086-2.984, p = 0.023) and heart failure (OR 2.410 95% CI 1.385-4.193, p = 0.002) independently predicted thrombotic events in this population. This study suggests that the P/F ratio is associated with thrombotic events by promoting a hypercoagulation state in patients hospitalized for COVID-19.

Prevalence of new-onset atrial fibrillation in hospitalized patients with community-acquired pneumonia: a systematic review and meta-analysis.

Community-acquired pneumonia (CAP) is a common lower respiratory tract infection, often complicated by cardiovascular events, including cardiac arrhythmias. New-onset atrial fibrillation (newAF) has been associated with increased mortality in CAP patients, especially in those critically ill; however, limited data on the prevalence of newAF in patients with CAP are available. We aim to estimate the pooled prevalence of newAF and its impact on adverse outcomes in patients with CAP, through a systematic review and meta-analysis. MEDLINE and EMBASE were systematically searched from inception to 27 January 2022. All studies reporting the prevalence of newAF in CAP patients were included and all-cause mortality was extracted when available. The pooled prevalence of newAF, 95% Confidence Intervals (CI), and 95% Prediction Intervals (PI) were computed. The inconsistency index (I2) was calculated to measure heterogeneity. Subgroup analyses were also performed. A protocol for this study was registered on PROSPERO (CRD42022307422). Among 7,655 records retrieved, 10 studies were included, with a total of 280,589 CAP patients. Pooled prevalence of newAF in CAP patients was 7.6% (95% CI 6.4-9.0%, 95% PI 4.3-13.1%, I2 = 95%). Subgroup analyses showed no significant differences according to geographical location or study design. Patients with newAF had a higher risk of mortality among the studies included in the systematic review. NewAF is a common complication, occurring in 7.6% of CAP patients, with prediction intervals suggesting an even higher burden. CAP patients who develop newAF during hospitalization may be at higher risk of mortality in both short- and long-term follow-up.

Breakthrough infections after COVID-19 vaccinations do not elicit platelet hyperactivation and are associated with high platelet-lymphocyte and low platelet-neutrophil aggregates.

Background: Severe COVID-19 is associated with an excessive immunothrombotic response and thromboinflammatory complications. Vaccinations effectively reduce the risk of severe clinical outcomes in patients with COVID-19, but their impact on platelet activation and immunothrombosis during breakthrough infections is not known. Objectives: To investigate how preemptive vaccinations modify the platelet-immune crosstalk during COVID-19 infections. Methods: Cross-sectional flow cytometry study of the phenotype and interactions of platelets circulating in vaccinated (n = 21) and unvaccinated patients with COVID-19, either admitted to the intensive care unit (ICU, n = 36) or not (non-ICU, n = 38), in comparison to matched SARS-CoV-2-negative patients (n = 48), was performed. Results: In the circulation of unvaccinated non-ICU patients with COVID-19, we detected hyperactive and hyperresponsive platelets and platelet aggregates with adaptive and innate immune cells. In unvaccinated ICU patients with COVID-19, most of whom had severe acute respiratory distress syndrome, platelets had high P-selectin and phosphatidylserine exposure but low capacity to activate integrin αIIbß3, dysfunctional mitochondria, and reduced surface glycoproteins. In addition, in the circulation of ICU patients, we detected microthrombi and platelet aggregates with innate, but not with adaptive, immune cells. In vaccinated patients with COVID-19, who had no acute respiratory distress syndrome, platelets had surface receptor levels comparable to those in controls and did not form microthrombi or platelet-granulocyte aggregates but aggregated avidly with adaptive immune cells. Conclusion: Our study provides evidence that vaccinated patients with COVID-19 are not associated with platelet hyperactivation and are characterized by platelet-leukocyte aggregates that foster immune protection but not excessive immunothrombosis. These findings advocate for the importance of vaccination in preventing severe COVID-19.

Sex and gender differences in community-acquired pneumonia.

Awareness of the influence of sex ands gender on the natural history of several diseases is increasing. Community-acquired pneumonia (CAP) is the most common acute respiratory disease, and it is associated with both morbidity and mortality across all age groups. Although a role for sex- and gender-based differences in the development and associated complications of CAP has been postulated, there is currently high uncertainty on the actual contribution of these factors in the epidemiology and clinical course of CAP. More evidence has been produced on the topic during the last decades, and sex- and gender-based differences have also been extensively studied in COVID-19 patients since the beginning of the SARS-CoV-2 pandemic. This review aims to provide an extensive outlook of the role of sex and gender in the epidemiology, pathogenesis, treatment, and outcomes of patients with CAP, and on the future research scenarios, with also a specific focus on COVID-19.

Serological Response and Relationship with Gender-Sensitive Variables among Healthcare Workers after SARS-CoV-2 Vaccination.

Vaccine-induced immunity is a key strategy in the long-term control of the COVID-19 pandemic. The aim of our study was to explore the relationship between mRNA vaccine-induced antibodies and gender-sensitive variables among healthcare workers. Two thousand-sixty-five volunteers who received the BNT162b2 vaccine were enrolled in the study and followed up. Demographic, clinical, and social variables (educational level, marital status, occupation, childcare) were evaluated through a self-administered questionnaire. Anti-Spike (S) IgG were measured at 1 month (T1) and at 5 months (T2) after the second vaccine dose. At T1, median anti-S IgG values were 693 [394−>800] AU/mL (1 AU = 2.6 BAU). Values > 800 AU/mL (2080 BAU/mL) were directly associated with a previous COVID-19 (p < 0.001) infection and inversely with age (p < 0.001), smoking habit (p < 0.001), and autoimmune diseases (p < 0.001). At T2, a significant decreasing in anti-S IgG values was observed (187 [81−262] AU/mL), with a median decrease of 72 [60−82]%. On multivariate data analysis, a reduction of more than 82% was directly associated with male sex (p < 0.021), age (p < 0.001), smoking (p = 0.038), hypertension (p = 0.042), and, inversely, with previous COVID-19 infection (p < 0.001) and being "cohabiting" (p = 0.005). Our findings suggest that demographic, clinical, and social variables play a role in anti-S IgG values decreasing in long-term follow up and should be considered to find personalized vaccine schedules.