Epidemiologic and Clinical Characteristics and Risk Factors for Severe Community-Acquired Clostridium Difficile Infection in Children.

Although children most frequently suffer from milder forms of community-acquired Clostridium difficile infection, severe cases and fatal outcomes have been recorded. In this study we identified older children (>12 years of age) and patients who had surgery up to 6 months before Clostridium difficile infection onset as a subgroup at somewhat higher risk for severe community-acquired Clostridium difficile infection.

A Comprehensive Analysis of Renal and Endothelium Dysfunction Markers Fourteen Years after Hemorrhagic Fever with Renal Syndrome Contraction.

While the pathology of acute hemorrhagic fever with renal syndrome (HFRS) has been widely researched, details on the chronic HFRS sequelae remain mainly unexplored. In this study, we analyzed the clinical and laboratory characteristics of 30 convalescent HFRS patients 14 years after the disease contraction, mainly emphasizing several endothelial dysfunction parameters. Convalescent HFRS patients exhibited significantly higher serum levels of erythrocyte sedimentation rate, von Willebrand factor, uric acid, C-reactive protein and immunoglobulin A when compared to healthy individuals. Furthermore, 24 h urine analyses revealed significantly lower sodium and potassium urine levels, as well as significantly higher proteinuria, microalbumin levels and ß2-microglobulin levels when compared to healthy individuals. First morning urine analysis revealed significantly higher levels of hematuria in convalescent HFRS patients. None of the additional analyzed endothelium dysfunction markers were significantly different in post-HFRS patients and healthy individuals, including serum and urine P-selectin, E-selectin, soluble intercellular adhesion molecule 1, vascular intercellular adhesion molecule 1 (sVCAM-1) and vascular endothelial growth factor (VEGF). However, binary logistic regression revealed a weak association of serum sVCAM-1 and urine VEGF levels with HFRS contraction. Generally, our findings suggest mild chronic inflammation and renal dysfunction levels in convalescent HFRS patients 14 years after the disease contraction.

Proinflammatory Chemokine Levels in Cerebrospinal Fluid of Patients with Neuroinvasive Flavivirus Infections.

Tick-borne encephalitis virus (TBEV) and West Nile virus (WNV) are the most important neuroinvasive arboviruses detected in Europe. In this study, we analyzed cerebrospinal fluid (CSF) concentrations of 12 proinflammatory chemokines (CCL2, CCL3, CCL4, CCL11, CCL17, CCL20, CXCL1, CXCL5, CXCL8, CXCL9, CXCL10, and CXCL11) in 77 patients with neuroinvasive diseases (NIDs). Flavivirus infection was confirmed in 62 patients (TBEV and WNV in 31 patients each), while in 15 patients the etiology of NID was not determined (NDE). Similar patterns of high-level expression of chemokines regulating monocyte/macrophage responses (CCL2), neutrophil recruitment (CXCL1 and CXCL8), and interferon-inducible chemoattractants for leukocytes (CXCL10 and CXCL11) have been observed in WNV and TBEV groups. None of the tested chemokines significantly differed between patients with TBEV or WNV. Concentrations of CCL17, CCL20, CXCL5, CXCL10, and CXCL11 were significantly lower in both WNV and TBEV groups compared to NID NDE patients. The logistic regression model showed that CSF concentrations of CXCL11, CXCL5, and CXCL10 could potentially be used for the classification of patients into the WNV or TBEV group versus groups with other NIDs. This study identified, for the first time, similar patterns of CSF chemokine expression in WNV and TBEV infections, suggesting common immunopathogenic mechanisms in neuroinvasive flavivirus infections that should be further evaluated.

Antiviral treatment significantly reduces the levels of CXCL9, CXCL10 and CXCL11 in chronic hepatitis C.

In this study, we aimed to elucidate the changes in the immune response during antiviral treatment of patients with chronic hepatitis C, with an emphasis on the chemokine dynamics and their association with liver fibrosis. Serum concentrations of 12 chemokines. (CCL2, CCL3, CCL4, CCL11, CCL17, CCL20, CXCL1, CXCL5, CXCL8, CXCL9, CXCL10 and CXCL11) were measured in 32 patients with chronic hepatitis C before direct-acting antiviral treatment and after sustained virological response using bead-based flow cytometry. Chemokine levels were also measured in 14 sex- and age-matched healthy individuals. Concentrations of CXCL9, CXCL10, CXCL11 and CCL20 were significantly higher in chronic hepatitis C patients before direct-acting antiviral treatment compared to healthy individuals. We also observed a significant reduction in CXCL9, CXCL10 and CXCL11 levels after sustained virological response. Furthermore, we demonstrated a strong positive correlation between CXCL9, CXCL10 and CXCL11 levels before antiviral treatment. When considering liver fibrosis, we found significantly higher levels of CXCL10 and lower levels of CCL17 and CXCL5 in pre-treatment patients with severe fibrosis. None of the analysed chemokines were able to predict METAVIR fibrosis score reduction after sustained virological response. The results of this study emphasize the importance of proinflammatory pathways in liver fibrosis immunopathology during chronic hepatitis C. Finally, our results also characterized CXCL10 as the chemokine which most accurately distinguished pre-treatment CHC patients and healthy individuals.

Hemorrhagic Fever with Renal Syndrome Patients Exhibit Increased Levels of Lipocalin-2, Endothelin-1 and NT-proBNP.

Hemorrhagic fever with renal syndrome (HFRS) is an acute zoonotic disease caused by viruses of the Orthohantavirus genus. This syndrome is characterized by renal and cardiopulmonary implications detectable with different biomarkers. Here, we explored the role of serum and urine levels of lipocalin-2, endothelin-1 and N-terminal pro-brain natriuretic peptide (NT-proBNP) in HFRS pathology. A total of twenty-eight patients hospitalized due to a Puumala orthohantavirus infection were included, with serum and urine samples collected on patient admission (acute phase) and discharge (convalescent phase). In comparison to healthy individuals, patients exhibited significantly higher acute-phase serum and urine levels of lipocalin-2, serum levels of endothelin-1 and serum and urine levels of NT-proBNP. Patients in the convalescent phase showed a significant decrease in urine lipocalin-2, serum endothelin-1 and serum and urine NT-proBNP levels. We recorded a strong correlation between serum levels of lipocalin-2 and endothelin-1 and urine levels of lipocalin-2 with several kidney injury markers, such as serum creatinine, urea, urine white blood cell count and proteinuria. We also demonstrated an independent correlation of serum and urine lipocalin-2 levels with acute kidney injury in HFRS. All in all, our results show an involvement of NT-proBNP, lipocalin-2 and endothelin-1 in the renal and cardiac pathology of HFRS.

Distribution of Epstein-Barr Virus LMP1 Variants in Patients with Infectious Mononucleosis and Association with Selected Biochemical and Hematological Parameters.

The molecular diversity of Epstein-Barr virus (EBV) is exceptionally complex and based on the characterization of sequences coding for several viral genes. The aim of this study was to analyze the distribution of EBV types 1 and 2 and to characterize LMP1 variants in a cohort of 73 patients with infectious mononucleosis (IM), as well as to investigate a possible association between viral diversity and relevant clinical parameters. Population-based sequencing of EBNA-2 gene showed the presence of EBV type 1 in all IM patients. Analysis of LMP1 gene found a restricted repertoire of LMP1 variants with the predominance of wild-type B95-8, China1, Mediterranean and North Carolina variants with the presence of more than one LMP1 variant in 16.4% of patients. Co-infections with different LMP1 variants were associated with significantly higher levels of C-reactive protein and lower levels of maximal neutrophil counts and minimal platelet count. The results of this study have shown a narrow repertoire of LMP1 variants and an exclusive presence of EBV type 1 in a cohort of IM from Croatia, suggesting a characteristic local molecular pattern of this virus. The clinical importance of distinct immunobiological features of IM patients with LMP1 variant co-infections needs to be investigated further.

Parents' attitudes toward childhood COVID-19 immunization in Croatia: a multicenter cross-sectional study.

AIM: To assess parents' attitudes toward childhood COVID-19 immunization in Croatia. METHODS: In this multicenter cross-sectional study, we collected data from four tertiary care facilities in Zagreb, Split, and Osijek between December 2021 and February 2022. During the visit to the Pediatric Emergency Departments, parents were asked to fill out a highly-structured questionnaire about their attitudes toward COVID-19 immunization in children. RESULTS: The sample consisted of 872 respondents. A total of 46.3% of respondents were hesitant about vaccinating their child against COVID-19, 35.2% definitely did not intend to vaccinate their child, and 18.5% definitely intended to vaccinate their child. Parents who were themselves vaccinated against COVID-19 were more likely than unvaccinated parents (29.2% and 3.2%, P<0.001) to vaccinate their children. Parents agreeing with the epidemiological guidelines were more inclined to vaccinate their children, as were parents of older children and parents of children vaccinated according to the national program schedule. Child comorbidities and respondents' history of COVID-19 were not associated with childhood vaccination intention. Ordinal logistic regression revealed that the most important predictors for a positive parents' attitude toward vaccinating their child were parents' vaccination status and regular vaccination of their child according to the national immunization program schedule. CONCLUSION: Our results demonstrate Croatian parents' mostly hesitant and negative attitudes toward childhood COVID-19 immunization. Future vaccination campaigns should target unvaccinated parents, parents with younger children, and parents of children with chronic diseases.

Distinct Expression Patterns of Genes Coding for Biological Response Modifiers Involved in Inflammatory Responses and Development of Fibrosis in Chronic Hepatitis C: Upregulation of SMAD-6 and MMP-8 and Downregulation of CAV-1, CTGF, CEBPB, PLG, TIMP-3, MMP-1, ITGA-1, ITGA-2 and LOX.

Background and Objectives: The aim of this study was to analyze the expression of genes on transcriptomic levels involved in inflammatory immune responses and the development of fibrosis in patients with chronic hepatitis C. Materials and Methods: Expression patterns of 84 selected genes were analyzed with real-time quantitative RT PCR arrays in the peripheral blood of treatment-naive patients with chronic hepatitis C and healthy controls. The panel included pro- and anti-fibrotic genes, genes coding for extracellular matrix (EMC) structural constituents and remodeling enzymes, cell adhesion molecules, inflammatory cytokines, chemokines and growth factors, signal transduction members of the transforming growth factor- beta (TGF-ß) superfamily, transcription factors, and genes involved in epithelial to mesenchymal transition. Results: The expression of SMAD-6 coding for a signal transduction TGF-beta superfamily member as well as MMP-8 coding for an ECM protein were significantly increased in CHC patients compared with controls. Conclusions: Chronic hepatitis C was also characterized by a significant downregulation of a set of genes including CAV-1, CTGF, TIMP-3, MMP-1, ITGA-1, LOX, ITGA-2, PLG and CEBPB encoding various biological response modifiers and transcription factors. Our results suggest that chronic hepatitis C is associated with distinct patterns of gene expression modulation in pathways associated with the regulation of immune responses and development of fibrosis.

Slower Waning of Anti-SARS-CoV-2 IgG Levels Six Months after the Booster Dose Compared to Primary Vaccination.

Anti-SARS-CoV-2 IgG titer decreases rapidly after primovaccination, leading to a mandatory booster vaccination. We analysed anti-SARS-CoV-2 Spike RBD IgG levels (positive ≥ 50 AU/mL) in 405 healthcare workers (3010 sera) who received a booster dose (BD) 9 months after two-dose BNT162b2 primovaccination. Median antibody titer at the time of BD (582.6 AU/mL) was 1.7-fold and 16.4-fold lower than the peak titer after the first (961.5 AU/mL) and the second vaccine dose (SVD) (10,232.6 AU/mL), respectively. One month after vaccination, IgG titer increased 40.6-fold after BD compared with a 10.8-fold increase after primovaccination. Three months after vaccination, post-booster antibodies decreased significantly slower (2.2-fold) than after primovaccination (3.3-fold). At six months, antibodies decreased slower after BD (4.5-fold; median 5556.0 AU/mL) than after primovaccination (9.6-fold; median 1038.5 AU/mL). Antibody titers before and one month after BD correlated weakly (r = 0.30) compared with a strong correlation (r = 0.65) between the corresponding post-primovaccination titers. Pre-vaccination COVID-19 had no effect on IgG levels after BD compared with a positive effect after primovaccination. Despite high post-booster IgG levels, 22.5% of participants contracted mild COVID-19. The trend of IgG decline indicates the need for further revaccination, but the vaccine type should be defined according to viral mutations.

The Effect of Treatment-Induced Viral Eradication on Cytokine and Growth Factor Expression in Chronic Hepatitis C.

In this study, we evaluated the effect of hepatitis C virus eradication using direct-acting antivirals (DAA) on the serum cytokine and growth factor profiles of chronic hepatitis C patients (CHC). Serum concentrations of 12 cytokines and 13 growth factors were measured in 56 patients with CHC before, during the DAA treatment and after sustained virological response using bead-based flow cytometry. Cytokine and growth factor levels were also measured in 15 healthy individuals. The majority of the selected cytokines and growth factors exhibited similar concentrations before, during and after successful DAA treatment, the exceptions being IL-10, EGF, HGF and VEGF. Significantly lower concentrations of IL-10, IL-13, IL-4, IL-4, IL-9, TNF- α and higher levels of Ang-2, HGF and SCF were observed in patients with CHC before and after DAA treatment compared with healthy individuals. Patients with severe fibrosis stages exhibited higher levels of Ang-2 and lower levels of EGF, PDGF-AA and VEGF. Furthermore, IL-4, IL-5 and SCF were characterized as potential biomarkers of DAA treatment using random forest. Additionally, logistic regression characterized EGF as a potential biomarker of severe CHC. Our results suggest inhibition of pro-inflammatory processes and promotion of liver regeneration in CHC patients during DAA treatment.

Decline of Anti-SARS-CoV-2 IgG Antibody Levels 6 Months after Complete BNT162b2 Vaccination in Healthcare Workers to Levels Observed Following the First Vaccine Dose.

Research on post-vaccination antibody dynamics has become pivotal in estimating COVID-19 vaccine efficacy. We studied anti-SARS-CoV-2 Spike RBD IgG levels in 587 healthcare workers (2038 sera) who completed BNT162b2 vaccination. Average antibody titer 3 weeks after the first dose in COVID-19-naïve participants (median 873.5 AU/mL) was 18-fold higher than the test threshold, with a significant increase 1 month (median 9927.2 AU/mL) and an exponential decrease 3 (median 2976.7 AU/mL) and 6 (median 966.0 AU/mL) months after complete vaccination. Participants with a history of COVID-19 prior to vaccination showed significantly higher antibody levels, particularly after the first dose (median 14,280.2 AU/mL), with a slight decline 1 month (median 12,700.0 AU/mL) and an exponential decline in antibody titers 3 (median 4831.0 AU/mL) and 6 (median 1465.2 AU/mL) months after vaccination. Antibody levels of COVID-19-naïve subjects after the first dose were moderately correlated with age (r = -0.4). Multivariate analysis showed a strong independent correlation between IgG levels 6 months after vaccination and both IgG titers after the first dose and 1 month after vaccination (R2 = 0.709). Regardless of pre-vaccination COVID-19 history, IgG levels 6 months after vaccination were comparable to antibody levels reached by COVID-19-naïve participants after the first vaccine dose.