Tenofovir disoproxil fumarate in the treatment of COVID-19: Evaluation of 78 patients.

One of the drugs that has been suggested for the treatment of SARS-CoV-2 infection is tenofovir disoproxil (TDF). Herein, it was aimed to evaluate the outcomes of TDF receiving COVID-19 cases in terms of day 7-10 PCR negativity and day 30 survival. Patients who received TDF due to PCR-confirmed COVID-19 between 27.04.2021 and 31.12.2021 were included in our study. The primary outcome was considered to be 7-10 days of PCR negativity, while the secondary outcome was considered 30-day survival after diagnosis of COVID-19. Patients who died before completing the treatment period (7-10 days) were also considered as PCR failures. Data were analyzed both in terms of intention to treat basis and in the subgroup that survived to the end of treatment. A total of 78 patients (30 women, mean age: 61.15±18.5 years) met the inclusion criteria. In the intention to treat analysis group, one-month-mortality was 44.87% (35/78) in the overall cohort. In the end of treatment analysis group, one-month-mortality was 29.5% (18/61) in the overall cohort. Day 7-10 PCR negativity was detected in 55.7% of the overall EOT cohort. Our data suggest that TDF may be an alternative salvage treatment option in antiviral unresponsive patients. We suggest evaluating TDF in well-designed controlled trials involving treatment-naïve cases.

The clinical features, treatment and prognosis of neutropenic fever and Coronavirus disease 2019 results of the multicentre teos study.

This multicentre (22 centres in Turkey) retrospective cohort study aimed to assess the clinical outcomes of patients with neutropenic fever and SARS-CoV-2 positivity. Study period was 15 March 2020-15 August 2021. A total of 170 cases (58 female, aged 59 ± 15.5 years) that fulfilled the inclusion criteria were included in the study. One-month mortality rate (OMM) was 44.8%. The logistic regression analysis showed the following significant variables for the mentioned dependent variables: (i) achieving PCR negativity: receiving a maximum of 5 days of favipiravir (p = 0.005, OR 5.166, 95% CI 1.639-16.280); (ii) need for ICU: receiving glycopeptide therapy at any time during the COVID-19/FEN episode (p = 0.001, OR 6.566, 95% CI 2.137-20.172), the need for mechanical ventilation (p < 0.001, OR 62.042, 95% CI 9.528-404.011); (iii) need for mechanical ventilation: failure to recover from neutropenia (p < 0.001, OR 17.869, 95% CI 3.592-88.907), receiving tocilizumab therapy (p = 0.028, OR 32.227, 95% CI 1.469-707.053), septic shock (p = 0.001, OR 15.4 96% CI 3.164-75.897), and the need for ICU (p < 0.001, OR 91.818, 95% CI 15.360-548.873), (iv) OMM: [mechanical ventilation (p = 0.001, OR 19.041, 95% CI 3.229-112.286) and septic shock (p = 0.010, OR 5.589,95% CI 1.509-20.700)]. Although it includes a relatively limited number of patients, our findings suggest that COVID-19 and FEN are associated with significant mortality and morbidity.

Organotypic lung tissue culture as a preclinical model to study host- influenza A viral infection: A case for repurposing of nafamostat mesylate.

Reliable and effective models for recapitulation of host-pathogen interactions are imperative for the discovery of potential therapeutics. Ex vivo models can fulfill these requirements as the multicellular native environment in the tissue is preserved and be utilized for toxicology, vaccine, infection and drug efficacy studies due to the presence of immune cells. Drug repurposing involves the identification of new applications for already approved drugs that are not related to the prime medical indication and emerged as a strategy to cope with slow pace of drug discovery due to high costs and necessary phases to reach the patients. Within the scope of the study, broad-spectrum serine protease inhibitor nafamostat mesylate was repurposed to inhibit influenza A infection and evaluated by a translational ex vivo organotypic model, in which human organ-level responses can be achieved in preclinical safety studies of potential antiviral agents, along with in in vitro lung airway culture. The safe doses were determined as 10 µM for in vitro, whereas 22 µM for ex vivo to be applied for evaluation of host-pathogen interactions, which reduced virus infectivity, increased cell/tissue viability, and protected total protein content by reducing cell death with the inflammatory response. When the gene expression levels of specific pro-inflammatory, anti-inflammatory and cell surface markers involved in antiviral responses were examined, the significant inflammatory response represented by highly elevated mRNA gene expression levels of cytokines and chemokines combined with CDH5 downregulated by 5.1-fold supported the antiviral efficacy of NM and usability of ex vivo model as a preclinical infection model.

COVID-19 Antibody Levels among Various Vaccination Groups, One-Year Antibody Follow-Up in Two University Hospitals from Western and Central Turkey.

Various clinical outcomes, reinfections, vaccination programs, and antibody responses resulted from the COVID-19 pandemic. This study investigated the time-dependent changes in SARS-CoV-2 antibody responses in infected and/or vaccinated and unvaccinated individuals and to provide insights into spike and nucleocapsid antibodies, which fluctuate during infectious and non-infectious states. This cohort study was carried out at the Ege University Faculty of Medicine hospital in Izmir (western Turkey) and the Erciyes University Faculty of Medicine hospital in Kayseri (central Turkey) between December 2021 and January 2023, which coincided with the second half of COVID-19 pandemic. The study included 100 COVID-19 PCR-positive patients and 190 healthcare workers (HCWs). Antibody levels were followed up via quantitative anti-SARS-CoV-2 spike and qualitative anti-nucleocapsid immunoassays (Elecsys™). Antibody levels declined after infection but persisted for at least 6-8 months. Individuals who had received only CoronaVac had higher anti-nucleocapsid antibody levels in the early months than those who received mixed vaccination. However, anti-spike antibodies persisted longer and at higher levels in individuals who had received mixed vaccinations. This suggests that combining two different vaccine platforms may provide a synergistic effect, resulting in more durable and broad-spectrum immunity against SARS-CoV-2. The study provides information about the vaccination and antibody status of healthcare workers in the second half of the pandemic and provides valuable insights into the dynamics of antibody responses to COVID-19 infection and vaccination.

Efficacy of coronavirus disease 2019 vaccines in patients with rheumatic diseases.

Objectives: In this study, we report the immune response to the BNT162b2 vaccine and CoronaVac vaccine after a two-dose vaccination and the effects of conventional drugs, immunosuppressive drugs, and new-generation therapies on vaccine responses in patients with rheumatic and musculoskeletal diseases (RMDs). Patients and methods: This is a prospective observational study conducted with 94 patients (65 males, 29 females; mean age: 42.7±12.1 years; range, 19 to 69 years) between May 2021 and January 2022. The immunogenicity of the two-dose regimens of the BNT162b2 and CoronaVac vaccines in adult patients with RMD was analyzed according to disease and treatments. Serum immunoglobulin G antibody levels against SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) spike proteins were measured four weeks after the second dose of vaccines. Results: Patients on regimens including mycophenolate, rituximab, and steroids were less likely to develop an antibody response (p=0.001, p=0.06, and p=0.001, respectively). Impairment of vaccine response by other conventional disease-modifying antirheumatic drugs and by anti-tumor necrosis factor treatments was not shown. Younger participants appeared more likely to develop an antibody response. The CoronaVac vaccine was less likely to develop an antibody response compared to the BNT162b2 vaccine (p=0.002). Systemic lupus erythematosus and vasculitis had the lowest antibody titers compared to other RMDs. Conclusion: Patients receiving mycophenolate mofetil, rituximab, and steroids should be warned about the risk of a suboptimal vaccine response. If possible, vaccination strategies should be changed, and the dose modification of drugs should be made during the vaccination. Further studies are required to determine the responses to SARS-CoV-2 vaccination and optimization of vaccine response in patients with RMDs.

SARS-CoV-2 reinfections in the pediatric cohort-a single-center experience.

BACKGROUND: This study focused on timelines of infection episodes and dominant variants and aims to determine disease severity and outcome of pediatric patients with reinfection. MATERIALS AND METHODS: This study retrospectively evaluated the medical records of the hospitalized patients and/or outpatients aged 0-18 with a positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) polymerase chain reaction between March 2020 and September 2022 at Ege University Children's Hospital. RESULTS: Ninety-one pediatric patients reinfected with SARS-CoV-2 were included in the study. There was an underlying disease in 26.4% of the patients. The median time between the two infection episodes was 184 (90-662) days. There were 24 patients (26.3%) with the first infection in pre-Delta period; 17 (18.6%) of them were reinfected in Omicron BA.1 period, while 7 (7.6%) in Omicron BA.4/BA.5 period. Forty-five patients (49.4%) were infected initially in the Delta period; 35 patients (38.4%) were reinfected in the Omicron BA.1 period, while 10 patients (10.9%) were reinfected in the Omicron BA.4/BA.5 period. Twenty-two patients (24.1%) had the first infection in the Omicron BA.1 period and then reinfected in the Omicron BA.4/BA.5 period. Patients with reinfection more frequently displayed a symptom (84.6% vs. 94.5%, p = 0.03). The hospitalization rate significantly declined in reinfection (15.3% vs. 7.6%, p = 0.03). Severe disease, treatment needs and steroid use were decreased in reinfections without a significant difference (p > 0.05). Intensive care unit admission was not altered. CONCLUSION: This study revealed that reinfections frequently develop in previously healthy children but do not cause more severe outcomes. The risk of symptomatic reinfections is still high due to the effect of the Omicron variant.

Antibody Response to SARS-CoV-2 Vaccination in Heart Failure Patients: Retrospective Single-Center Cohort Study.

We sought to investigate the impact of heart failure on anti-spike antibody positivity following SARS-CoV-2 vaccination. Our study included 103 heart failure (HF) patients, including those with and without left ventricular assist devices (LVAD) selected from our institutional transplant waiting list as well as 104 non-heart failure (NHF) patients who underwent open heart surgery at our institution from 2021 to 2022. All the patients received either heterologous or homologous doses of BNT162b2 and CoronaVac. The median age of the HF group was 56.0 (interquartile range (IQR): 48.0-62.5) and the NHF group was 63.0 (IQR: 56.0-70.2) years, and the majority were males in both groups (n = 78; 75.7% and n = 80; 76.9%, respectively). The majority of the patients in both the HF and NHF groups received heterologous vaccinations (n = 43; 41.7% and n = 52; 50.3%, respectively; p = 0.002). There was no difference in the anti-spike antibody positivity between the patients with and without heart failure (p = 0.725). Vaccination with BNT162b2 led to significantly higher antibody levels compared to CoronaVac alone (OR: 11.0; 95% CI: 3.8-31.5). With each passing day after the last vaccine dose, there was a significant decrease in anti-spike antibody positivity, with an OR of 0.9 (95% CI: 0.9-0.9). Furthermore, hyperlipidemia was associated with increased antibody positivity (p = 0.004).

Post-Vaccination Detection of SARS-CoV-2 Antibody Response with Magnetic Nanoparticle-Based Electrochemical Biosensor System.

Here, we report magnetic nanoparticle-based biosensor platforms for the rapid detection of SARS-CoV-2 antibody responses in human serum. The use of the proposed system enabled the detection of anti-SARS-CoV-2 spike (S) and nucleocapsid (N) proteins at a concentration of ng/mL in both buffer and real serum samples. In particular, the protocol, which is considered an indicator of innate immunity after vaccination or post-infection, could be useful for the evaluation of antibody response. We included a total of 48 volunteers who either had COVID-19 but were not vaccinated or who had COVID-19 and were vaccinated with CoronoVac or Biontech. Briefly, in this study, which was planned as a cohort, serum samples were examined 3, 6, and 12 months from the time the volunteers' showed symptoms of COVID-19 with respect to antibody response in the proposed system. Anti-S Ab and anti-N Ab were detected with a limit of detection of 0.98 and 0.89 ng/mL, respectively. These data were confirmed with the corresponding commercial an electrochemiluminescence immunoassay (ECLIA) assays. Compared with ECLIA, more stable data were obtained, especially for samples collected over 6 months. After this period, a drop in the antibody responses was observed. Our findings showed that it could be a useful platform for exploring the dynamics of the immune response, and the proposed system has translational use potential for the clinic. In conclusion, the MNP-based biosensor platform proposed in this study, together with its counterparts in previous studies, is a candidate for determining natural immunity and post-vaccination antibody response, as well as reducing the workload of medical personnel and paving the way for screening studies on vaccine efficacy.

Importance of screening severe COVID-19 patients for IFN-λ1, IL-6 and anti-S1 IgG levels.

Cytokine storm is an important cause of death in COVID-19 patients. A recent clinical study showed that administration of recombinant interferon lambda 1 (IFN-λ1 or IL-29) may prevent severe COVID-19. On the other hand, IL-6 has been associated as a prognostic marker of worsening for COVID-19 patients. The objective of this study is to screen IFN-λ1, IL-6 and antibody levels in consecutive serum sample sets of COVID-19 patients. A total of 365 serum samples collected from 208 hospitalized COVID-19 patients were analyzed for IFN-λ1 and IL-6 levels as well as SARS-CoV-2 neutralizing antibodies and anti-S1 IgG antibodies. Analyses of serum samples for cytokine levels showed that IFN-λ1 (>8 pg/mL) and IL-6 (>2 pg/mL) were detected in approximately 64% and 21% patients, respectively. A decrement in IFN-λ1 levels and IL-6 levels above 35 pg/mL can be sign of clinical severity and upcoming dead. An increment in IL-6 levels wasn't detected in every COVID-19 patient but a decrement in IL-6 levels was related to clinical improvement. Importantly, the detection of IFN-λ1 level together with an increase in anti-S1 IgG antibody response were observed in clinically improved patients. Screening severe COVID-19 patients for IFN-λ1, IL-6, and anti-S1 IgG antibody levels during their hospital stay especially in intensive care units may be beneficial to monitor the clinical status and management of treatment strategies. Importantly, detection of IFN-λ1 together with protective IgG antibody response can be an indication of clinical improvement in severe COVID-19 patients and these patients may be discharged from the hospital soon.

COVID-19 Infection, Vaccination, and Antibody Levels: Investigating Correlations through a Cohort Study.

AIM: The objective of this study was to explore the potential correlation between COVID-19 infection or vaccination and levels of anti-nucleocapsid (anti-N) and anti-spike (anti-S) antibodies. METHODS: Among 6050 healthcare workers at the Ege University Hospital, a cohort study with 162 participants divided into three arms with 54 participants each was conducted. The three groups were selected as follows: those diagnosed with COVID-19 and not vaccinated (group 1), those diagnosed with COVID-19 and subsequently vaccinated with CoronaVac (group 2), and those not diagnosed with COVID-19 but vaccinated with two doses of CoronaVac (group 3). Antibody levels measured at the sixth month of follow-up were defined as the primary outcome. RESULTS: At the sixth month, all serum samples tested positive for anti-S. Anti-S levels were found to be significantly higher in group 2 than in the other groups (p < 0.001). There were no differences in antibody levels between groups 1 and 3 (p = 0.080). Average antibody levels were found to be lower in office workers and males. Anti-N antibodies were found to be positive in 85.1% of subjects at the sixth month. In group 2, anti-N antibodies were detected in all samples at the sixth month. Anti-N antibody levels were not significantly different between groups 1 and 2 (p = 0.165). Groups 1 and 2 had significantly higher antibody levels than group 3 (p < 0.001). CONCLUSIONS: Vaccination or infection provide protection for at least 6 months. Those who have previously been diagnosed with COVID-19 do not need to be vaccinated in the early period before their antibody levels decrease.

[Autophagy Markers Induced by Influenza Virus and MUC1 Expressions in Cancer-Derived Cell Lines]. / Kanser Kökenli Hücre Dizilerinde Influenza Virüsünün Indükledigi Otofaji Belirteçleri ile MUC1 Ekspresyonu Arasindaki Iliskinin Arastirilmasi.

Influenza virus-induced autophagy is often accompanied by apoptosis and results in cell death in virus-infected cells. It is well known that autophagy is modulated by the mTOR/PI3K/Akt pathway, which plays an important role in the response to the presence of energy sources and external stimuli. This pathway is modulated by mucin 1 (MUC1), which has extracellular and intracellular components and plays an important role in metastasis and chemotherapeutic resistance. In this study, it was aimed to investigate the expression of MUC1 after the inoculation of influenza viruses into the cancer-derived cell cultures and, accordingly, the changes in autophagy markers such as mTOR and LC3B. In this study, MCF-7, HeLa and A-549 cell lines were used which have adenocarcinoma origin. To control the growth of influenza virus in these cells, the MDCK cell line was also inoculated. Centrifuge-enhanced shell-vial cell culture method was used in all experiments. Influenza A (H1N1) pdm09 strain was inoculated into these cell lines then the expressions of viral nucleic acid and cycle threshold (Ct) of MUC1, mTOR, LC3B associated genes were investigated by quantitative real-time reverse transcriptase polymerase chain reaction (qRTPCR) method in the samples taken from the supernatants of all cells at the end of the 48-hour incubation period. To investigate whether these markers were present in cells, after all cells were permeabilized with paraformaldehyde, cell-coated infected coverslips were stained with fluorescent labeled monoclonal antibodies developed against MUC1, mTOR, LC3B and influenza virus antigens. In the examination of fluorescence microscopy, all of the cell cultures (MCF-7, He-La and A-549) infected with influenza virus yielded positive results in terms of LC3B, mTOR and MUC1 monoclonal antibody staining, whereas all of the non-infected cells were found negative. Cycle threshold values of MUC1, LC3B and mTOR associated genes were found to be lower in A-549 cell line inoculated with influenza virus. Although protein expression was demonstrated in MCF-7 and He-La cell lines, similar changes were not detected in the 1/Ct values of genes in the autophagy pathway. The Ct value of the MUC1 gene was found to be higher only in the MCF-7 cell line after inoculation. In conclusion, it was observed that the specific expression pattern for influenza virus-induced autophagy was formed only in the A-549 cell line among the adenocarcinoma cells. It was thought that this relationship could constitute a dataset in further research on lung adenocarcinoma. However, in future studies, the determination of the expression of these genes at the protein level by using further tests will provide better comparison of the results.

Retrospective Evaluation of COVID-19 Infection and COVID-19 Vaccines in Heart Transplant Patients.

BACKGROUND: Patients who have performed solid organ transplantation in terms of COVID-19 infection are included in the high-risk group. In this study, it was aimed to evaluate the relationship between vaccination and retrospective evaluation of 32 patients who underwent a heart transplant in the clinic and tested positive for SARS-CoV-2 polymerase chain reaction. METHODS: In this study, demographic characteristics of the cases, comorbidities, timing of heart transplantation, immunosuppressive treatments, symptoms of COVID-19 infection, lung imaging findings, follow-up (outpatient/inpatient), treatments, 1-month mortality, and vaccination histories against COVID-19 infection were evaluated. The data obtained from the study were analyzed with SPSS version 25.0. RESULTS: The 3 most common symptoms are cough (37.5%), myalgia (28.1%), and fever (21.8%). COVID-19 infection was severe in 6.2% of the patients, moderate in 37.5%, and mild in 56.2%. Hospitalization was required in 5 patients (15.6%, 1 in the intensive care unit), and the other patients were followed up as an outpatient. Severe COVID-19 infection was seen more in 33% of unvaccinated patients; 93.5% were vaccinated. Nineteen patients (68%) were vaccinated before COVID-19 infection. Our patients received the CoronoVac (Sinovac, China) vaccine. CONCLUSION: COVID-19 infection is more likely to be severe and mortal in patients with heart transplant recipients. It is also crucial to comply with preventive measures other than immunization in this group of patients. This study is the largest series investigating COVID-19 infection in heart transplant recipient patients in our country.

Cardiac Assessment in Children with MIS-C: Late Magnetic Resonance Imaging Features.

Multisystem Inflammatory Syndrome (MIS-C) is a new entity that emerges 2-4 weeks after the SARS-CoV-2 infection in children. MIS-C can affect all systems, the most severe of which is cardiac involvement. The duration of the cardiac symptoms is still uncertain and may be persistent or prolonged. The American College of Rheumatology Clinical Guidelines recommends cardiac magnetic resonance imaging (MRI) 2-6 months after the diagnosis of MIS-C in patients presenting with significant transient left ventricular (LV) dysfunction in the acute phase of illness (LV ejection fraction 50%) or persistent LV dysfunction. There are a few studies investigating cardiac MRI findings in MIS-C patients. In this study, we aimed to evaluate cardiac MRI findings, at the earliest 3 months after diagnosis, and compare these findings with the echocardiograms in children with MIS-C. A retrospective study including 34 MIS-C patients was conducted at a tertiary-level University Hospital between June 2020 and July 2021. Centers for Disease Control and Prevention criteria were used in the diagnosis of MIS-C. Cardiac MRI was performed at least 3 months after MIS-C diagnosis. The study included 17 (50%) boys and 17 (50%) girls with a mean age of 9.31 ± 4.72 years. Initial echocardiographic evaluation revealed cardiac abnormality in 13 (38.2) patients; 4 (11.8%) pericardial effusion, 4 (11.8%) left ventricular ejection fraction (LVEF) < 55%, and 5 (14.7%) coronary artery dilatation. Echocardiography showed normal LV systolic function in all patients during follow-up; coronary dilatation persisted in 2 of 5 (40%) patients at the 6th-month visit. Cardiac MRI was performed in 31 (91.2%) patients, and myocardial hyperemia was not detected in any patients (T1 relaxation time was < 1044 ms in all children). However, 9 (29%) patients' MRI showed isolated elevated T2 levels, and 19 (61.3%) revealed at least one of the following findings: pericardial effusion, right ventricular dysfunction, or LVEF abnormality. In patients with MIS-C, a high rate of cardiac involvement, particularly pericardial effusion was determined by cardiac MRI performed at the earliest 2-6 months after diagnosis. Even if echocardiography does not reveal any abnormality in the initial phase, cardiac MRI should be suggested in MIS-C patients in the late period. This is the first study reporting cardiac MRI findings in the late period of MIS-C patients.

Comparison of a novel antigen detection test with reverse transcription polymerase chain reaction assay for laboratory diagnosis of SARS-CoV-2 infection.

Molecular diagnosis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by real-time reverse transcription polymerase chain reaction (RT-PCR) in respiratory specimens is considered the gold standard method. This method is highly sensitive and specific but it has some limitations such as being expensive and requiring special laboratory equipment and skilled personnel. RapidFor™ Antigen Rapid Test Kit is a commercially available Ag-RDT which is produced in Turkey and designed to detect the nucleocapsid antigen of SARS-CoV-2 in nasopharyngeal swab samples. The aim of this study was to evaluate the performance of this novel SARS-CoV-2 antigen detection considering the RT-PCR method as the gold standard. Four hundred forty-four nasopharyngeal swab samples which were collected from the patients who met clinical criteria of COVID-19 from ten centers in Turkey between September 2020 and February 2021 were included in the study. All the nasopharyngeal swab samples were tested for SARS-CoV-2 RNA using commercial RT-PCR kits (Bioeksen and A1 Lifesciences, Istanbul, Turkey) according to the manufacturer's instructions. Viral loads were assessed according to the cycle threshold (Ct) values. RapidFor™ SARS-CoV-2 antigen test (Vitrosens Biotechnology, Istanbul, Turkey) was used to investigate the presence of SARS-CoV-2 antigen in all samples following the manufacturer's instructions. Out of 444 nasopharyngeal swab samples tested, 346 (77.9%) were positive and 98 (22.1%) were negative for SARS-CoV-2 RNA by RTPCR. Overall sensitivity of the RapidFor™. Antigen Rapid Test Kit was 80.3% whereas specificity was found to be 87.8%. Positivity rate of rapid antigen test in samples with Ct values over 25 and below 30 was 82.7%, while it increased to 95.7% in samples 20 ≤ Ct < 25 and reached 100% in samples with Ct values below 20. RapidFor™ SARS-CoV-2 Ag test might be a good choice in the screening of symptomatic and asymptomatic patients and their contacts for taking isolation measures early, with advantages over RT-PCR as being rapid, easy and being applicable in every laboratory and even at point of care.

Quantitative Antibody Levels Against SARS-CoV-2 Spike Protein in COVID-19 and Multisystem Inflammatory Syndrome in Children.

The majority of children with coronavirus diseases 2019 (COVID-19) are asymptomatic or develop mild symptoms, and a small number of patients require hospitalization. Multisystem inflammatory syndrome in children (MIS-C) is one of the most severe clinical courses of COVID-19 and is suggested to be a hyperinflammatory condition. This study aimed to compare quantitative antibody levels against SARS-CoV-2 spike protein in children with COVID-19 and MIS-C. Blood samples from 75 patients [n = 36 (48%) with mild/asymptomatic (group 1), n = 22 (29.3%) with moderate-to-severe SARS-CoV-2 infection (group 2) and n = 17 (22.6%) patients with MIS-C (group 3)] were analyzed 3 months after COVID-19. The majority of the children with asymptomatic/mild COVID-19 symptoms (80.6%), moderate/severe disease (90.9%), and MIS-C (82.4%) had detectable IgG antibodies to SARS-CoV-2 spike protein (p = 0.567). The mean antibody value against SARS-CoV-2 spike protein was 321.9 ± 411.6 in group 1, 274 ± 261 in group 2, and 220 ± 299 in group 3, respectively (p > 0.05). Patients diagnosed with COVID-19 (asymptomatic/mild+moderate/severe) and those with MIS-C were also compared; the antibody positivity rates [COVID-19 group: 85.5%, MIS-C group: 82.4%, (p = 0.833)] and mean antibody values [COVID-19 group: 303.9 ± 360.3, MIS-C group: 220 ± 299, (p > 0.05)] were similar in both groups. In conclusion, the majority of children with COVID-19 and MIS-C developed a detectable antibody level against SARS-CoV-2 spike protein 3 months after COVID-19. Quantitative antibody levels were similar in both asymptomatic/mild disease, moderate/severe disease, and MIS-C group. Long-term studies evaluating antibody responses in children with COVID-19 and MIS-C are needed for more accurate vaccine schedules.

Clinical and Laboratory Findings of SARS-CoV-2 Infection in Children Younger than 6 Months Old: Neutropenia is More Common Not Lymphopenia.

BACKGROUND: Studies on age-related differences in clinical and laboratory features of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection are limited. We aimed to evaluate the demographic, clinical, laboratory findings of SARS-CoV-2 infection in children younger than 6 months old and compare them with older children. METHODS: A single-center retrospective study, including 209 confirmed SARS-CoV-2 infection cases, was conducted between 11 March 2020 and 1 September 2021. The case group consisted of 47 patients younger than 6 months old, whereas the control group consisted of 162 patients older than 6 months old. RESULTS: The mean age of the case group was 2.77 ± 1.52 months, and the control group was 101.89 ± 65.77 months. Cough was statistically higher in the control group, and poor feeding was higher in the case group (p = 0.043, 0.010). The underlying disease rate was statistically higher in the control group; however, the hospitalization rate was higher in the case group (p = 0.036, 0.001). The case group had significantly lower median values of the absolute neutrophil count, hemoglobin and higher median values of white blood cell, absolute lymphocyte count and platelet than the control group (p < 0.05). C-reactive protein, fibrinogen values were significantly lower, and procalcitonin, D-dimer, troponin T, N-terminal pro-B-type natriuretic peptide significantly higher in the case group (p < 0.05). Lymphopenia was more common in the control group, whereas neutropenia was more common in the case group (p = 0.001, 0.011). CONCLUSIONS: We showed that most children younger than 6 months old had mild and asymptomatic SARS-CoV-2 infection; however, the hospitalization rate was higher, and neutropenia was more common in older children. Lay summaryStudies on age-related differences in clinical and laboratory features on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in pediatric patients are limited. We aimed to evaluate the demographic, clinical and laboratory findings of SARS-CoV-2 infection in children younger than 6 months old and compare them with older children. A single-center retrospective study was conducted, including 209 SARS-CoV-2 infection cases. The case group consisted of 47 patients younger than 6 months old, and the control group consisted of 162 patients older than 6 months old. Most children younger than 6 months old had mild and asymptomatic SARS-CoV-2 infection; however, the hospitalization rate was higher than older children. Neutropenia was more common in patients younger than 6 months than older children with SARS-CoV-2 infection, even if underlying diseases were excluded.

Fluorescent bioassay for SARS-CoV-2 detection using polypyrene-g-poly(ε-caprolactone) prepared by simultaneous photoinduced step-growth and ring-opening polymerizations.

The construction of a rapid and easy immunofluorescence bioassay for SARS-CoV-2 detection is described. We report for the first time a novel one-pot synthetic approach for simultaneous photoinduced step-growth polymerization of pyrene (Py) and ring-opening polymerization of ε-caprolactone (PCL) to produce a graft fluorescent copolymer PPy-g-PCL that was conjugated to SARS-CoV-2-specific antibodies using EDC/NHS chemistry. The synthesis steps and conjugation products were fully characterized using standard spectral analysis. Next, the PPy-g-PCL was used for the construction of a dot-blot assay which was calibrated for applications to human nasopharyngeal samples. The analytical features of the proposed sensor showed a detection range of 6.03-8.7 LOG viral copy mL-1 (Ct Scores: 8-25), the limit of detection (LOD), and quantification (LOQ) of 1.84 and 6.16 LOG viral copy mL-1, respectively. The repeatability and reproducibility of the platform had a coefficient of variation (CV) ranging between 1.2 and 5.9%. The fluorescence-based dot-blot assay was tested with human samples. Significant differences were observed between the fluorescence intensity of the negative and positive samples, with an overall correct response of 93.33%. The assay demonstrated a high correlation with RT-PCR data. This strategy opens new insights into simplified synthesis procedures of the reporter molecules and their high potential sensing and diagnosis applications.

Indiscriminate SARS-CoV-2 multivariant detection using magnetic nanoparticle-based electrochemical immunosensing.

The increasing mutation frequency of the SARS-CoV-2 virus and the emergence of successive variants have made correct diagnosis hard to perform. Developing efficient and accurate methods to diagnose infected patients is crucial to effectively mitigate the pandemic. Here, we developed an electrochemical immunosensor based on SARS-CoV-2 antibody cocktail-conjugated magnetic nanoparticles for the sensitive and accurate detection of the SARS-CoV-2 virus and its variants in nasopharyngeal swabs. The application of the antibody cocktail was compared with commercially available anti-SARS-CoV-2 S1 (anti-S1) and anti-S2 monoclonal antibodies. After optimization and calibration, the limit of detection (LOD) determination demonstrated a LOD = 0.53-0.75 ng/mL for the antibody cocktail-based sensor compared with 0.93 ng/mL and 0.99 ng/mL for the platforms using anti-S1 and anti-S2, respectively. The platforms were tested with human nasopharyngeal swab samples pre-diagnosed with RT-PCR (10 negatives and 40 positive samples). The positive samples include the original, alpha, beta, and delta variants (n = 10, for each). The polyclonal antibody cocktail performed better than commercial anti-S1 and anti-S2 antibodies for all samples reaching 100% overall sensitivity, specificity, and accuracy. It also showed a wide range of variants detection compared to monoclonal antibody-based platforms. The present work proposes a versatile electrochemical biosensor for the indiscriminate detection of the different variants of SARS-CoV-2 using a polyclonal antibody cocktail. Such diagnostic tools allowing the detection of variants can be of great efficiency and economic value in the fight against the ever-changing SARS-CoV-2 virus.

Benign acute childhood myositis associated with influenza A/B in the paediatric emergency department and the efficacy of early-onset oseltamivir.

AIM: To investigate the association of benign acute childhood myositis (BACM) with respiratory viruses. Also, we aimed to assess the effect of antiviral treatment on the improvement and complications. METHODS: This study was conducted at an urban-academic emergency department during four influenza-seasons (2016-2019), retrospectively. Demographics, clinical findings, laboratories, metabolic disease analyses and serological features were extracted from the medical records. Treatments, complications and outcomes were also recorded. RESULTS: A total of 114 children were included. The median age was 7.0 (min 1.25-max 17) years and 78.9% were male. The most common symptoms were leg pain (91.2%), anorexia (54.4%), fever (45.6%), sore throat (42.1%) and walking difficulty (32.5%). On admission, the median creatine phosphokinase level was 3332 IU/L (range, 1634-50 185), median aspartate aminotransferase 107 U/L (range, 38-1798). In the multiplex polymerase chain reaction analysis, 40.4% influenza B, 36.8% influenza A, 7.8% adenovirus, 7.8% parainfluenza virus, 5.3% rhinovirus, 5.3% respiratory syncytial virus and 1.8% Mycoplasma pneumoniae were detected. Rhabdomyolysis was developed in 6.7% and acute renal failure was seen in two patients. Oseltamivir was given in 44 (38.6%) patients who had influenza A/B. Metabolic disease screening tests were performed in 33.3% of patients and metabolic diseases were detected in 4 (3.5%) patients. The median recovery time was lower in patients with oseltamivir treatment (4 (min 2-max 5) - 5 (min 3-max 10) days) (P < 0.001). CONCLUSION: Rhabdomyolysis is more common in BACM due to the influenza A virus. The early use of oseltamivir treatment was significantly associated with a shorter recovery time.

'All In One' SARS-CoV-2 variant recognition platform: Machine learning-enabled point of care diagnostics.

Point of care (PoC) devices are highly demanding to control current pandemic, originated from severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2). Though nucleic acid-based methods such as RT-PCR are widely available, they require sample preparation and long processing time. PoC diagnostic devices provide relatively faster and stable results. However they require further investigation to provide high accuracy and be adaptable for the new variants. In this study, laser-scribed graphene (LSG) sensors are coupled with gold nanoparticles (AuNPs) as stable promising biosensing platforms. Angiotensin Converting Enzyme 2 (ACE2), an enzymatic receptor, is chosen to be the biorecognition unit due to its high binding affinity towards spike proteins as a key-lock model. The sensor was integrated to a homemade and portable potentistat device, wirelessly connected to a smartphone having a customized application for easy operation. LODs of 5.14 and 2.09 ng/mL was achieved for S1 and S2 protein in the linear range of 1.0-200 ng/mL, respectively. Clinical study has been conducted with nasopharyngeal swabs from 63 patients having alpha (B.1.1.7), beta (B.1.351), delta (B.1.617.2) variants, patients without mutation and negative patients. A machine learning model was developed with accuracy of 99.37% for the identification of the SARS-Cov-2 variants under 1 min. With the increasing need for rapid and improved disease diagnosis and monitoring, the PoC platform proved its potential for real time monitoring by providing accurate and fast variant identification without any expertise and pre sample preparation, which is exactly what societies need in this time of pandemic.