Proteomic snapshot of saliva samples predicts new pathways implicated in SARS-CoV-2 pathogenesis.

BACKGROUND: Information on the microbiome's human pathways and active members that can affect SARS-CoV-2 susceptibility and pathogenesis in the salivary proteome is very scarce. Here, we studied a unique collection of samples harvested from April to June 2020 from unvaccinated patients. METHODS: We compared 10 infected and hospitalized patients with severe (n = 5) and moderate (n = 5) coronavirus disease (COVID-19) with 10 uninfected individuals, including non-COVID-19 but susceptible individuals (n = 5) and non-COVID-19 and nonsusceptible healthcare workers with repeated high-risk exposures (n = 5). RESULTS: By performing high-throughput proteomic profiling in saliva samples, we detected 226 unique differentially expressed (DE) human proteins between groups (q-value ≤ 0.05) out of 3376 unambiguously identified proteins (false discovery rate ≤ 1%). Major differences were observed between the non-COVID-19 and nonsusceptible groups. Bioinformatics analysis of DE proteins revealed human proteomic signatures related to inflammatory responses, central cellular processes, and antiviral activity associated with the saliva of SARS-CoV-2-infected patients (p-value ≤ 0.0004). Discriminatory biomarker signatures from human saliva include cystatins, protective molecules present in the oral cavity, calprotectins, involved in cell cycle progression, and histones, related to nucleosome functions. The expression levels of two human proteins related to protein transport in the cytoplasm, DYNC1 (p-value, 0.0021) and MAPRE1 (p-value, 0.047), correlated with angiotensin-converting enzyme 2 (ACE2) plasma activity. Finally, the proteomes of microorganisms present in the saliva samples showed 4 main microbial functional features related to ribosome functioning that were overrepresented in the infected group. CONCLUSION: Our study explores potential candidates involved in pathways implicated in SARS-CoV-2 susceptibility, although further studies in larger cohorts will be necessary.

Conventional versus extended-pulsed fidaxomicin dosing in patients at high risk of recurrence of Clostridioides difficile infection: a propensity score analysis.

INTRODUCTION: The main challenge in the treatment of Clostridioides difficile infection (CDI) is to reduce recurrence rates. Fidaxomicin improves the recurrence rate of CDI compared with vancomycin. Extended-pulsed dosing of fidaxomicin was associated with lower recurrence rates in one clinical trial but has never been directly compared with conventional fidaxomicin dosing. METHODS: To compare the recurrence rate of fidaxomicin conventional dosing (FCD) and fidaxomicin in extended-pulsed dosing (FEPD) in conditions of clinical practice at a single institution. We performed propensity score matching taking the variables age, severity and previous episode as confounders to evaluate patients with a similar recurrence risk. RESULTS: In total, 254 episodes of CDI treated with fidaxomicin were evaluated: 170 (66.9%) received FCD, and 84 (33.1%) received FEPD. More patients who received FCD were hospitalized for CDI, had severe CDI and had a diagnosis based on toxin detection. In contrast, the proportion of patients receiving proton pump inhibitors was higher in those receiving FEPD. The crude recurrence rates in FCD- and FEPD-treated patients were 20.0% and 10.7%, respectively (OR:0.48; 95% CI 0.22-1.05; P = 0.068). We did not find any differences in CDI recurrence rate in patients receiving FEPD versus FCD (OR = 0.74; 95% CI 0.27-2.04) by propensity score analysis. CONCLUSIONS: Although the recurrence rate with FEPD was numerically lower than that observed with FCD, we have not been able to show that the recurrence rate of CDI is different depending on the dosage regimen of fidaxomicin. Clinical trials or large observational studies comparing the two dosing regimens of fidaxomicin are needed.

Metabolic Snapshot of Plasma Samples Reveals New Pathways Implicated in SARS-CoV-2 Pathogenesis.

Despite the scientific and human efforts to understand COVID-19, there are questions still unanswered. Variations in the metabolic reaction to SARS-CoV-2 infection could explain the striking differences in the susceptibility to infection and the risk of severe disease. Here, we used untargeted metabolomics to examine novel metabolic pathways related to SARS-CoV-2 susceptibility and COVID-19 clinical severity using capillary electrophoresis coupled to a time-of-flight mass spectrometer (CE-TOF-MS) in plasma samples. We included 27 patients with confirmed COVID-19 and 29 healthcare workers heavily exposed to SARS-CoV-2 but with low susceptibility to infection ("nonsusceptible"). We found a total of 42 metabolites of SARS-CoV-2 susceptibility or COVID-19 clinical severity. We report the discovery of new plasma biomarkers for COVID-19 that provide mechanistic explanations for the clinical consequences of SARS-CoV-2, including mitochondrial and liver dysfunction as a consequence of hypoxemia (citrulline, citric acid, and 3-aminoisobutyric acid (BAIBA)), energy production and amino acid catabolism (phenylalanine and histidine), and endothelial dysfunction and thrombosis (citrulline, asymmetric dimethylarginine (ADMA), and 2-aminobutyric acid (2-AB)), and we found interconnections between these pathways. In summary, in this first report several metabolic pathways implicated in SARS-CoV-2 susceptibility and COVID-19 clinical progression were found by CE-MS based metabolomics that could be developed as biomarkers of COVID-19.

Unravelling hip-spine bone mineral density discordance in people living with HIV.

INTRODUCTION: In people living with HIV (PLWH), bone mineral density (BMD) discordance between the lumbar spine (LS) and femoral neck (FN) could be frequent given the high frequency of secondary osteoporosis, including HIV-related factors for bone disease. MATERIALS AND METHODS: Retrospective cohort of PLWH with a dual X-ray absorptiometry scan. Hip-spine BMD discordance was defined as different T-score or Z-scores categories at LS and FN. RESULTS: Overall, 865 individuals (mean 49.5 years, female 27%) were included. Osteoporosis diagnosis was four-to-seven times lower when both skeletal sites were affected than when considering the lowest T-score at any site (overall, 21% vs 4%). Hip-spine BMD discordance was observed in 381 (44%) individuals, it increased with age (from 43 to 52%, P = 0.032), and it was mainly due to lower LS-BMD. A lower FN-BMD was associated with older age, lower BMI (P < 0.01), and HIV-related factors, such as low CD4 + T-cell counts, duration of HIV infection, and time on antiretroviral therapy (ART). In a multivariate regression analysis, sex male (Odds Ratio, OR 4.901), hyperparathyroidism (OR, 2.364), and time on ART (OR 1.005 per month) were independently associated with discordance. A higher estimated fracture risk by FRAX equation was observed in individuals with BMD discordance due to lower FN-BMD compared to those with lower LS-BMD (+ 36% for major osteoporotic fracture, P = 0.04; + 135% for hip fracture, P < 0.01). CONCLUSION: Hip-spine BMD discordance is highly prevalent in PLWH and it is associated with classical and HIV-related risk factors, modifying the rate of osteoporosis and fracture risk estimation.

Low risk of bacterial co-infection, opportunistic diseases, and persistent immunosuppression in people living with HIV and COVID-19.

PURPOSE: SARS-CoV-2 infection produces lymphopenia and CD4+ T-cell decrease, which could lead to a higher risk of bacterial co-infection or impair immunological evolution in people living with HIV (PLWH). METHODS: We investigated the rate of co-infection and superinfection, and the evolution of CD4+ count and CD4+/CD8+ ratio, in hospitalized PLWH with COVID-19. RESULTS: From March to December 2020, 176 PLWH had symptomatic COVID-19 and 62 required hospitalization (median age, 56 years, 89% males). At admission, 7% and 13% of patients had leukocytosis or increased procalcitonin values and 37 (60%) received empiric antibiotic therapy, but no bacterial co-infection was diagnosed. There were seven cases of superinfection (12%), and one case of P. jiroveci pneumonia during ICU stay. No significant change in CD4+ count or CD4+/CD8+ ratio was observed after discharge. CONCLUSION: Bacterial co-infection is not frequent in PLWH with COVID-19. Immune recovery is observed in most of patients after the disease.

Progressive and Parallel Decline of Humoral and T-Cell Immunity in Convalescent Healthcare Workers with Asymptomatic or Mild-to-Moderate Severe Acute Respiratory Syndrome Coronavirus 2 Infection.

We investigated the duration of humoral and T-cell immune response in paired samples among 22 convalescent healthcare workers (HCWs). A median of 1.8 months after diagnosis, T-cell response was significantly lower in HCWs with early loss of antibodies (6 cases [27%]). After 5.1 months, antibody decline was observed in 77% of cases (41% seroreverted; P < .01), and 36% had lost T-cell response (75% lost response to spike protein). Persistence of immune response was observed in those who developed a greater adaptive immune response. Our data point to the initial immune response as the relevant player in coronavirus disease 2019 duration of protection.

Immune deficiency is a risk factor for severe COVID-19 in people living with HIV.

OBJECTIVES: A prior T cell depletion induced by HIV infection may carry deleterious consequences in the current COVID-19 pandemic. Clinical data on patients co-infected with HIV and SARS-CoV-2 are still scarce. METHODS: This multicentre cohort study evaluated risk factors for morbidity and mortality of COVID-19 in people living with HIV (PLWH), infected with SARS-CoV-2 in three countries in different clinical settings. COVID-19 was clinically classified as to be mild-to-moderate or severe. RESULTS: Of 175 patients, 49 (28%) had severe COVID-19 and 7 (4%) patients died. Almost all patients were on antiretroviral therapy (ART) and in 94%, HIV RNA was below 50 copies/mL prior to COVID-19 diagnosis. In the univariate analysis, an age 50 years or older, a CD4+ T cell nadir of < 200/µl, current CD4+ T cells < 350/µl and the presence of at least one comorbidity were significantly associated with severity of COVID-19. No significant association was found for gender, ethnicity, obesity, a detectable HIV RNA, a prior AIDS-defining illness, or tenofovir (which was mainly given as alafenamide) or protease inhibitor use in the current ART. In a multivariate analysis, the only factor associated with risk for severe COVID-19 was a current CD4+ T cell count of < 350/µl (adjusted odds ratio 2.85, 95% confidence interval 1.26-6.44, p=0.01). The only factor associated with mortality was a low CD4 T cell nadir. CONCLUSIONS: In PLWH, immune deficiency is a possible risk factor for severe COVID-19, even in the setting of virological suppression. There is no evidence for a protective effect of PIs or tenofovir alafenamide.

IFN-γ+ cell response and IFN-γ release concordance after in vitro SARS-CoV-2 stimulation.

BACKGROUND: Healthcare workers (HCWs) are at increased risk since they are directly exposed to SARS-CoV-2-infected patients, and nevertheless, some remain without the development of anti-SARS-CoV-2 antibodies or related symptoms, suggesting less susceptibility to the infection. METHODS: This cross-sectional, case-control study aimed to compare SARS-CoV-2 T-cell response by two different technologies, the analysis of IFN-γ+ CD8+ /CD4+ T cells by flow cytometry and the quantification of IFN-γ release by ELISA-related assay (without cell discrimination), both after SARS-CoV-2 stimulation among uninfected and convalescent HCWs. RESULTS: A high proportion of uninfected HCWs (53.8%) had pre-existing IFN-γ+ CD8 T-cell response after stimulation with at least one of the structural viral proteins S, M or N, while 35.9% had pre-existing IFN-γ+ CD4 T-cell response. This proportion was nearly or greater than 90% among convalescent HCWs. Interestingly, the magnitude of the response in uninfected was lower compared to that found in convalescent HCWs, using both methods. The concordance, quantifying the specific cellular response in convalescent HCWs, between both methods was 94.1% comparing CD8 T-cell response and 89.7% comparing CD4 T-cell response. This concordance was lower but still high in uninfected HCWs (76.5%) comparing CD8 T-cell response and 71.8% comparing CD4 T-cell response. CONCLUSIONS: The good concordance between the proportion of individuals with IFN-γ release after SARS-COV-2 stimulation with the proportion of individuals with specific IFN-γ+ CD8/CD4 T cells found in this study drives IFN-γ release assays to be a simple and easy way to determine the protective immunity to SARS-CoV-2 in a wide population.

Effectiveness of boosted darunavir plus rilpivirine in patients with long-lasting HIV-1 infection: DARIL study.

BACKGROUND: The combination of boosted darunavir plus rilpivirine, once daily, could be a convenient, effective and well-tolerated two-drug regimen to achieve HIV suppression in HIV-infected patients. METHODS: Multicentre, retrospective cohort study in nine hospitals in Spain. All HIV-infected subjects starting boosted darunavir plus rilpivirine were included, irrespective of their viral load (VL). The primary objective was the percentage of patients with VL <50 copies/mL at 48 weeks. Secondary objectives included changes in CD4+ cell count, lipid profile and renal function. RESULTS: Eighty-one of 84 patients reached Week 48. Fifty-nine (70.2%) patients had VL <50 copies/mL at baseline and the rest had a median VL of 202 (IQR 98-340) copies/mL. Subjects had a median of 21 years of infection with six prior regimens. The main reasons for starting boosted darunavir plus rilpivirine were simplification (44%), kidney or bone toxicity (28.6%) and virological failure (17.9%). Historical genotypes from 47 patients showed 41 (87.2%) patients with NRTI RAMs, 21 (44.7%) with NNRTI RAMs, 12 (25.5%) with primary PI RAMs and 7 (14.9%) with integrase strand transfer inhibitor (INSTI) RAMs. One patient had low-level resistance to boosted darunavir and five patients had some resistance to rilpivirine. At 48 weeks, 71 (87.7%) patients had VL <50 copies/mL. According to undetectable or detectable baseline VL, effectiveness was 91.1% or 80%, respectively. There were four virological failures with no emergence of new RAMs. Three of these patients resuppressed viraemia while maintaining the same regimen. CONCLUSIONS: The combination of boosted darunavir plus rilpivirine has shown good effectiveness and tolerability in this cohort of pretreated patients with a long-lasting HIV infection, exposure to multiple antiretroviral regimens and prior HIV resistance.

Lower T cell response against SARS-CoV-2 variants of concern after mRNA vaccine and risk of breakthrough infections in people with HIV.

OBJECTIVES: We evaluated T-cell immune responses against SARS-CoV-2 variants of concern (VOC) after vaccination in people with HIV (PWH), and their impact on the incidence of disease. METHODS: A prospective cohort study. Peripheral blood mononuclear cells (PBMCs) were collected a median of 53 days after second dose of mRNA vaccine. Humoral response and T cell responses against the spike (S) glycoprotein of wild-type SARS-CoV-2 (ancestral Wuhan variant) and mutated S-protein regions found in the Delta and Omicron variants were assessed by flow cytometry analysis. RESULTS: In 142 PWH without preceding SARS-CoV-2 infection, bivariate correlations showed a close association between T-cell responses to the different variants. However, despite at least 70% of PWH having a cellular immune response to any variant, CD4 + and CD8 + T cell responses against VOC were lower in frequency and magnitude (-3% and -20% for Delta, -33% and -28% for Omicron variant) compared with that observed against the Wuhan strain. A higher magnitude of SARS-CoV-2 spike-specific CD8 + T cell responses against all the variants was observed in those PWH with greater immune reconstitution. Notably, 27 symptomatic breakthrough infections (19%) in the setting of Delta and Omicron transmission were observed during follow-up, associated with a significant lower humoral and T-cell response to ancestral strain and VOC. On the contrary, only one PWH with COVID-19 (4%) required hospitalization. CONCLUSION: A blunted T-cell response against Delta and Omicron variant is observed in PWH who received two doses of mRNA vaccine. This lower immune response is associated with breakthrough SARS-CoV-2 infections.

Impact of Previous Common Human Coronavirus Exposure on SARS-CoV-2-Specific T-Cell and Memory B-Cell Response after mRNA-Based Vaccination.

OBJECTIVE: T-cell responses against SARS-CoV-2 are observed in unexposed individuals, attributed to previous common human coronavirus (HCoV) infections. We evaluated the evolution of this T-cell cross-reactive response and the specific memory B-cells (MBCs) after the SARS-CoV-2 mRNA-based vaccination and its impact on incident SARS-CoV-2 infections. METHODS: This was a longitudinal study of 149 healthcare workers (HCWs) that included 85 unexposed individuals that were subdivided according to previous T-cell cross-reactivity, who were compared to 64 convalescent HCWs. Changes in specific T-cell response and memory B-cell (MBC) levels were compared at baseline and after two doses of the SARS-CoV-2 mRNA-based vaccine. RESULTS: A cross-reactive T-cell response was found in 59% of unexposed individuals before vaccination. Antibodies against HKU1 positively correlated with OC43 and 229E antibodies. Spike-specific MBCs was scarce in unexposed HCWs regardless of the presence of baseline T-cell cross-reactivity. After vaccination, 92% and 96% of unexposed HCWs with cross-reactive T-cells had CD4+ and CD8+ T-cell responses to the spike protein, respectively. Similar results to that were found in convalescents (83% and 92%, respectively). Contrarily, higher than that which was observed in unexposed individuals without T-cell cross-reactivity showed lower CD4+ and CD8+ T-cell responses (73% in both cases, p = 0.03). Nevertheless, previous cross-reactive T-cell response was not associated with higher levels of MBCs after vaccination in unexposed HCWs. During a follow-up of 434 days (IQR, 339-495) after vaccination, 49 HCWs (33%) became infected, with a significant positive correlation between spike-specific MBC levels and isotypes IgG+ and IgA+ after vaccination and a longer time to get infected. Interestingly, T-cell cross-reactivity did not reduce the time to vaccine breakthrough infections. CONCLUSION: While pre-existing T-cell cross-reactivity enhances the T-cell response after vaccination, it does not increase SARS-CoV-2-specific MBC levels in the absence of previous infection. Overall, the level of specific MBCs determines the time to breakthrough infections, regardless of the presence of T-cell cross-reactivity.

A Risk Assessment Tool for Predicting Fragility Fractures in People with HIV: Derivation and Internal Validation of the FRESIA Model.

People with HIV have a higher risk of fracture than the general population. Because of the low performance of the existing prediction tools, there is controversy surrounding fracture risk estimation in this population. The aim of the study was to develop a model for predicting the long-term risk of fragility fractures in people with HIV. We included 11,899 individuals aged ≥30 years from the Spanish HIV/AIDS research network cohort. We identified incident fragility fractures from medical records, defined as nontraumatic or those occurring after a casual fall, at major osteoporotic sites (hip, clinical spine, forearm, proximal humerus). Our model accounted for the competing risk of death and included 12 candidate predictors to estimate the time to first fragility fracture. We assessed the discrimination and calibration of the model and compared it with the FRAX tool. The incidence rate of fragility fractures was 4.34 (95% CI 3.61 to 5.22) per 1000 person-years. The final prediction model included age, chronic kidney disease, and chronic obstructive pulmonary disease as significant predictors. The model accurately predicted the 5- and 10-year risk of fragility fractures, with an area under the receiving operator characteristic curve of 0.768 (95% CI 0.722 to 0.814) and agreement between the observed and expected probabilities. Furthermore, it demonstrated better discrimination and calibration than the FRAX tool, improving the classification of over 35% of individuals with fragility fractures compared to FRAX. Our prediction model demonstrated accuracy in predicting the long-term risk of fragility fractures. It can assist in making personalized intervention decisions for individuals with HIV and could potentially replace the current tools recommended for fracture risk assessment in this population. © 2023 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

mRNA-based SARS-CoV-2 Comirnaty vaccine elicits weak and short specific memory B cell response in individuals with no previous infection.

Objectives: The dynamics of the memory B cell (MBC) repertoire after SARS-CoV-2 vaccination is crucial for assessing long-term immunity. We compare spike-specific MBC responses between SARS-CoV-2 unexposed and recovered individuals, and their impact on breakthrough infections during follow-up. Methods: Spike-specific MBC and T cells were quantified at inclusion and after two doses of mRNA vaccine in a longitudinal cohort of 85 naïve and 64 recovered participants (47 with positive serology and 17 with negative serology after infection). Results: At inclusion, there was minimal spike-specific MBC in naïve SARS-CoV-2 individuals. After the second vaccine dose, MBCs were significantly boosted in naïve individuals, but reached a significantly lower level than that observed even in unvaccinated SARS-CoV-2 convalescents (p<0.001). Furthermore, while the secondary memory B cell (MBC) population consisted of 100%, 33%, and 76% IgG+, IgM+, and IgA+ expressing cells, respectively, in the unexposed group, the MBC response showed a significant decrease across all isotypes. Similarly, although secondary specific IgG+, IgM+, and IgA+-MBC isotypes were found in 100%, 39%, and 76% of the unexposed participants, respectively, the magnitude of the MBC levels was significantly lower for all the isotypes compared to convalescents. Interestingly, convalescents without an initial serological response had a lower MBC response, like what found in unexposed subjects. There was an inverse correlation between specific MBCs (r=-0.307; p=0.027), especially for isotype IgA+ (r=-0.279, p=0.045), and the time since the second vaccination dose. Furthermore, during a median follow-up of 434 days (IQR, 339-495), 49 out of 149 individuals (33%) became infected, 29 in naïve and 20 in convalescent individuals, showing a significant correlation between spike-specific MBC magnitude after vaccination and the time for SARS-CoV-2 infection, especially for IgA+/IgG+ MBC isotypes. Conclusions: MBCs were primed by mRNA-based vaccination in most cases, but SARS-CoV-2 naïve individuals had a blunted specific MBC response, and this was associated with a shorter time to breakthrough SARS-CoV-2 infection.

Improving Recognition of Fracture Risk in People with Human Immunodeficiency Virus: Performance and Model Contribution of Two Common Risk Assessment Tools.

Current guidelines recommend screening people with HIV (PWH) for bone disease using predictive tools developed for the general population, although data on PWH are scarce. In this study, we assessed the performance of FRAX and QFracture scoring systems to predict the occurrence of fragility fractures in a prospective cohort of 17,671 adults with human immunodeficiency virus (HIV) included in the HIV/AIDS research network (CoRIS) in Spain. The survival estimates of fragility fractures during follow-up were calculated and FRAX and QFracture scores were computed at cohort inclusion. For both tools, discriminatory measures and the observed-to-expected (O/E) ratios were assessed. During a follow-up time of 42,411.55 person-years, 113 fragility fractures were recorded. Areas under the curve were 0.66 [95% confidence interval (95% CI) 0.61-0.71] for FRAX and 0.67 (95% CI 0.62-0.73) for QFracture for major osteoporotic fractures, and 0.72 (95% CI 0.57-0.88) and 0.81 (95% CI 0.68-0.95) for hip fracture, respectively. The O/E was 1.67 for FRAX and 5.49 for QFracture for major osteoporotic fractures, and 11.23 for FRAX and 4.87 for QFracture for hip fractures. Moreover, O/E raised as the risk increased for both tools and in almost all age groups. When using the recommended assessment thresholds, <6% and 10% of major osteoporotic and hip fractures would have been identified, respectively. In conclusion, FRAX and QFracture displayed acceptable discrimination, although both tools significantly underestimated the risk of fragility fractures in PWH. The recommended assessment thresholds may not be appropriate for this population as they were unable to identify individuals with fragility fractures during follow-up.

Differential abundance of lipids and metabolites related to SARS-CoV-2 infection and susceptibility.

The mechanisms driving SARS-CoV-2 susceptibility remain poorly understood, especially the factors determining why unvaccinated individuals remain uninfected despite high-risk exposures. To understand lipid and metabolite profiles related with COVID-19 susceptibility and disease progression. We collected samples from an exceptional group of unvaccinated healthcare workers heavily exposed to SARS-CoV-2 but not infected ('non-susceptible') and subjects who became infected during the follow-up ('susceptible'), including non-hospitalized and hospitalized patients with different disease severity providing samples at early disease stages. Then, we analyzed their plasma metabolomic profiles using mass spectrometry coupled with liquid and gas chromatography. We show specific lipids profiles and metabolites that could explain SARS-CoV-2 susceptibility and COVID-19 severity. More importantly, non-susceptible individuals show a unique lipidomic pattern characterized by the upregulation of most lipids, especially ceramides and sphingomyelin, which could be interpreted as markers of low susceptibility to SARS-CoV-2 infection. This study strengthens the findings of other researchers about the importance of studying lipid profiles as relevant markers of SARS-CoV-2 pathogenesis.

Cefto Real-Life Study: Real-World Data on the Use of Ceftobiprole in a Multicenter Spanish Cohort.

BACKGROUND: Ceftobiprole is a fifth-generation cephalosporin that has been approved in Europe solely for the treatment of community-acquired and nosocomial pneumonia. The objective was to analyze the use of ceftobiprole medocaril (Cefto-M) in Spanish clinical practice in patients with infections in hospital or outpatient parenteral antimicrobial therapy (OPAT). METHODS: This retrospective, observational, multicenter study included patients treated from 1 September 2021 to 31 December 2022. RESULTS: A total of 249 individuals were enrolled, aged 66.6 ± 15.4 years, of whom 59.4% were male with a Charlson index of four (IQR 2-6), 13.7% had COVID-19, and 4.8% were in an intensive care unit (ICU). The most frequent type of infection was respiratory (55.8%), followed by skin and soft tissue infection (21.7%). Cefto-M was administered to 67.9% of the patients as an empirical treatment, in which was administered as monotherapy for 7 days (5-10) in 53.8% of cases. The infection-related mortality was 11.2%. The highest mortality rates were identified for ventilator-associated pneumonia (40%) and infections due to methicillin-resistant Staphylococus aureus (20.8%) and Pseudomonas aeruginosa (16.1%). The mortality-related factors were age (OR: 1.1, 95%CI (1.04-1.16)), ICU admission (OR: 42.02, 95%CI (4.49-393.4)), and sepsis/septic shock (OR: 2.94, 95%CI (1.01-8.54)). CONCLUSIONS: In real life, Cefto-M is a safe antibiotic, comprising only half of prescriptions for respiratory infections, that is mainly administered as rescue therapy in pluripathological patients with severe infectious diseases.

Impact of SARS-CoV-2-specific memory B cells on the immune response after mRNA-based Comirnaty vaccine in seronegative health care workers.

Purpose: To analyze the impact of SARS-COV-2-specific memory B cells (MBC) on the immune response after two doses of mRNA-based Comirnaty COVID-19 vaccine in seronegative health care workers. This study is seeking a rationale for boosting vaccines. Methods: Longitudinal study including 31 seronegative health care workers with undetectable specific MBCs (IgG-MBC- group), 24 seronegative with detectable specific MBCs (IgG-MBC+ group), and 24 seropositive with detectable specific MBCs (IgG+MBC+ group). The level of antibodies that inhibit ACE2-RBD interaction, and anti-Spike IgG, IgA, and IgM antibodies was quantified by ELISA. In addition, specific memory B and T cells were quantified by flow cytometry. Results: The level of specific MBCs, and isotypes, in the IgG-MBC- group was lower compared to that found in IgG-MBC+ (p = 0.0001) and IgG+MBC+ (p < 0.0001) groups, respectively. ACE2-RBD neutralizing antibodies and anti-S IgG antibodies were at lower levels in the IgG-MBC-group after the vaccine. Specific MBCs directly correlated with specific CD4+ T cells (although not significant, p = 0.065), while no correlation was found with specific CD8+ T cells (p = 0.156) after the vaccine. In parallel, ACE2-RBD neutralizing antibodies only positively correlated with specific CD4+ T cells (p = 0.034). Conclusion: IgG-MBC- individuals showed the worst humoral and cellular responses, both in frequency and magnitude, after vaccination. Individuals whose antibodies wane and become undetectable after a given period of time post vaccination and show no specific MBCs are less protected and hence are good candidates for boosting vaccine. On the other hand, seronegative individuals with specific MBC showed faster and higher responses compared to the IgG-MBC- group.

Pre-existing T cell immunity determines the frequency and magnitude of cellular immune response to two doses of mRNA vaccine against SARS-CoV-2.

Little is known about the factors associated with lack of T-cell response to mRNA vaccines against SARS-CoV-2. In a prospective cohort of 61 health care workers (HCWs), 21% and 16% after the first dose of mRNA BNT162b vaccine, and 12% and 7% after the second dose, showed lack of CD4+ and CD8+ T-cell response, respectively. Pre-existing T-cell immunity, due to past infection (46%) or cross-reactive cellular response (26%), was significantly associated with T-cell response in frequency (CD4+ T-cell, 100% vs 82% after two doses; p = 0.049) and in the magnitude of T-cell response during follow up. Furthermore, baseline CD4+ T-cell correlated positively with the titer of specific IgG-antibodies after first and second vaccine dose. Our data demonstrate that cross-reactive T-cells correlate with a better cellular response as well as an enhanced humoral response, and we confirm the close correlation of humoral and cellular response after mRNA vaccination.

Risk of SARS-CoV-2 Reinfections in a Prospective Inception Cohort Study: Impact of COVID-19 Vaccination.

The risk of reinfection could be related to the initial SARS-CoV-2 clinical presentation, but there are no data about the risk change after SARS-CoV-2 vaccination. We evaluated the rate of reinfection in an inception cohort study of 4943 health care workers (HCWs) according to symptoms and serologic results during March−May 2020. Incidence rates (IR) and IR ratios (IRR) before and after SARS-CoV-2 vaccination were determined by adjusting Poisson models. Overall, 1005 HCWs (20.3%) referred COVID-19 suggestive symptoms during the first surge of disease, and 33.5% and 55% presented a positive PCR or serology result, respectively. Meanwhile, 13% of asymptomatic HCWs had specific antibodies. During a follow up of 3422.2 person-years before vaccination, the rate of reinfection among seropositive individuals was 81% lower for those who were symptomatic compared with those who were asymptomatic (IRR of 0.19; 95% CI, 0.05−0.67; p = 0.003). During the 3100 person-years period after vaccination, an overall 74% decrease in the rate of infection was observed (IRR of 0.26; 95% CI, 0.21−0.32; p < 0.001), with a significant 83% and 70% decrease in seropositive and seronegative HCWs, respectively. In conclusion, the risk of SARS-CoV-2 reinfections is closely related to the clinical and serological presentation of COVID-19. COVID-19 vaccination further decreases the risk of reinfection more markedly among seropositive.

Lost in Translation: Evaluation of Subcutaneous Interferon-ß Treatment for SARS-CoV-2 Infection in Real Life.

Despite in vitro activity of interferon-ß (IFN-ß) against SARS-CoV-2 infection, its clinical efficacy remains controversial. We evaluated the impact of IFN-ß treatment in a cohort of 3590 patients hospitalized with COVID-19 during March−April 2020. The primary endpoint was a composed variable of admission to intensive care unit (ICU)/death. Overall, 153 patients (4%) received IFN-ß. They were significantly more severely ill, with a worse clinical and analytical situation, explaining a higher ICU admission (30% vs. 17%; p < 0.01), and a shorter time to the composed variable. In a Cox regression analysis, older age, lymphopenia, renal failure, or increased neutrophil-to-lymphocyte ratio were associated with a greater hazard ratio (HR) of admission at ICU/death. Notably, the HR of IFN-ß for the outcome variable was no longer significant after adjustment (HR, 1.03; 95% CI, 0.82−1.30), and different sensitivity analysis (early IFN use, ICU admission) showed no changes in the estimates. A propensity score matching analysis showed no association of IFN-ß therapy and outcome. In conclusion, in this large cohort of hospitalized COVID-19 patients, IFN-ß was used mainly in patients with advanced disease, reflecting an important bias of selection. After adjusting by severity, IFN-ß was not associated with a higher rate of ICU admission or mortality.