Advanced Biomedical Research on COVID-19

Background: Despite advanced diagnosis and treatment, infective endocarditis (IE) is a potentially life-threatening condition. The impact of COVID-19 on the diagnosis and outcome of the surgical treatment of IE is uncertain. The aim of this study was to analyze the incidence, characteristics, and outcomes of surgically treated IE before and after the COVID-19 pandemic. Methods: This study retrospectively analyzed the data of 535 patients who underwent valve surgical procedures for IE between January 2010 and December 2022 in a single cardiac surgery center. Patients were divided into two groups depending on the date of their operation: before (n = 393) and after (n = 142) COVID-19 onset. In order to balance the groups, inverse probability of treatment weighting (IPTW) calculated from the propensity score (PS) was applied. Weighted univariate logistic regressions were reported for outcomes; weights were derived from IPTW. Interrupted time series analysis (ITSA) according to Linden’s method was used to evaluate the changes in the manifestation of IE after 11 March 2020. Results: Patients from the post-COVID-19 cohort (after 11 March 2020) had a greater number of comorbidities such as diabetes (29.6% vs. 16.3% p = 0.001), hypertension (71.1% vs. 59.5% p = 0.015), and preoperative kidney injury requiring dialysis (9.2% vs. 2.5% p = 0.002), but the median additive and logistic EuroSCORE were not statistically different. In the post-COVID-19 group, we observed a greater prevalence of Staphylococcus aureus-related endocarditis (24.5% vs. 15.4% p = 0.026), a consequent reduction in Staphylococcus non aureus-related endocarditis (12.2% vs. 20.1% p = 0.048), and a decrease in aortic valve replacements (43.0% vs. 53.9%), while the number of mitral valve replacements and repair was greater (21.1% vs. 15.0% and 6.3% vs. 4.3%, respectively). No differences were found in the two groups concerning early death, death, or relapse at 1 year after surgery. Data obtained by multivariable analysis identified preoperative renal dysfunction requiring dialysis as the only common risk factor for early mortality via stratifying by time periods in analysis. Conclusions: The incidence of surgically treated IE significantly increases after the COVID-19 pandemic with a higher incidence of mitral valve involvement with respect to the aortic valve. Although a delay in surgical timing occurred during the COVID-19 pandemic, data in terms of mortality and outcomes were largely unaffected. Full article

Severe COVID-19 alters the biochemical and morphological characteristics of blood cells in a wide variety of ways. To date, however, the vast majority of research has been devoted to the study of leukocytes, while erythrocyte morphological changes have received significantly less attention. The aim of this research was to identify erythrocyte morphology abnormalities that occur in COVID-19, compare the number of different poikilocyte types, and measure erythrocyte sizes to provide data on size dispersion. Red blood cells obtained from 6 control donors (800–2200 cells per donor) and 5 COVID-19 patients (800–1900 cells per patient) were examined using low-voltage scanning electron microscopy. We did not discover any forms of erythrocyte morphology abnormalities that would be specific to COVID-19. Among COVID-19 patients, we observed an increase in the number of acanthocytes (p = 0.01) and a decrease in the number of spherocytes (p = 0.03). In addition, our research demonstrates that COVID-19 causes an increase in the median (p = 0.004) and interquartile range (p = 0.009) when assessing erythrocyte size. The limitation of our study is a small number of participants. Full article

The primary aim of this study was to determine the minimal clinically important difference (MCID) for the EuroQol-5D questionnaire (EQ-5D-5L) index and visual analogic scale (VAS) in individuals experiencing long-term post-COVID-19 symptoms. In addition, it was pretended to determine which variable discriminates better and to compare changes between individuals classified by the MCID. Design: Secondary analysis of a randomized controlled trial involving 42 individuals who underwent an 8-week intervention in a respiratory muscle training program. Results: A change of at least 0.262 and 7.5 for the EQ-5D-5L index and VAS represented the MCID, respectively. Only the EQ-5D-5L VAS showed acceptable discrimination between individuals who were classified as “improved” and those classified as “stable/not improved” (area under the curve = 0.78), although with a low Youden index (Youden index, 0.39; sensitivity, 46.2%; specificity, 93.1%). Those individuals who exceeded the established MCID for EQ-5D-5L VAS had significantly greater improvements in inspiratory muscle function, exercise tolerance, and peripheral muscle strength compared to participants classified as “stable/not improved”. Conclusions: Only the EQ-5D-5L VAS, especially when MCID was exceeded, showed an acceptable discriminative ability to evaluate the efficacy of an intervention in individuals with long-term post-COVID-19 symptoms. Full article

Background: Oxidative stress (OS) could cause various COVID-19 complications. Recently, we have developed the Pouvoir AntiOxydant Total (PAOT®) technology for reflecting the total antioxidant capacity (TAC) of biological samples. We aimed to investigate systemic oxidative stress status (OSS) and to evaluate the utility of PAOT® for assessing TAC during the recovery phase in critical COVID-19 patients in a rehabilitation facility. Materials and Methods: In a total of 12 critical COVID-19 patients in rehabilitation, 19 plasma OSS biomarkers were measured: antioxidants, TAC, trace elements, oxidative damage to lipids, and inflammatory biomarkers. TAC level was measured in plasma, saliva, skin, and urine, using PAOT and expressed as PAOT-Plasma, -Saliva, -Skin, and -Urine scores, respectively. Plasma OSS biomarker levels were compared with levels from previous studies on hospitalized COVID-19 patients and with the reference population. Correlations between four PAOT scores and plasma OSS biomarker levels were analyzed. Results: During the recovery phase, plasma levels in antioxidants (γ-tocopherol, β-carotene, total glutathione, vitamin C and thiol proteins) were significantly lower than reference intervals, whereas total hydroperoxides and myeloperoxidase (a marker of inflammation) were significantly higher. Copper negatively correlated with total hydroperoxides (r = 0.95, p = 0.001). A similar, deeply modified OSS was already observed in COVID-19 patients hospitalized in an intensive care unit. TAC evaluated in saliva, urine, and skin correlated negatively with copper and with plasma total hydroperoxides. To conclude, the systemic OSS, determined using a large number of biomarkers, was always significantly increased in cured COVID-19 patients during their recovery phase. The less costly evaluation of TAC using an electrochemical method could potentially represent a good alternative to the individual analysis of biomarkers linked to pro-oxidants. Full article

The spread of SARS-CoV-2 variants of concern (VOCs) is of great importance since genetic changes may increase transmissibility, disease severity and reduce vaccine effectiveness. Moreover, these changes may lead to failure of diagnostic measures. Therefore, variant-specific diagnostic methods are essential. To date, genetic sequencing is the gold-standard method to discriminate between variants. However, it is time-consuming (taking several days) and expensive. Therefore, the development of rapid diagnostic methods for SARS-CoV-2 in accordance with its genetic modification is of great importance. In this study we introduce a Mass Spectrometry (MS)-based methodology for the diagnosis of SARS-CoV-2 in propagated in cell-culture. This methodology enables the universal identification of SARS-CoV-2, as well as variant-specific discrimination. The universal identification of SARS-CoV-2 is based on conserved markers shared by all variants, while the identification of specific variants relies on variant-specific markers. Determining a specific set of peptides for a given variant consists of a multistep procedure, starting with an in-silico search for variant-specific tryptic peptides, followed by a tryptic digest of a cell-cultured SARS-CoV-2 variant, and identification of these markers by HR-LC-MS/MS analysis. As a proof of concept, this approach was demonstrated for four representative VOCs compared to the wild-type Wuhan reference strain. For each variant, at least two unique markers, derived mainly from the spike (S) and nucleocapsid (N) viral proteins, were identified. This methodology is specific, rapid, easy to perform and inexpensive. Therefore, it can be applied as a diagnostic tool for pathogenic variants. Full article