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.

Human Cytomegalovirus (HCMV) Genetic Diversity, Drug Resistance Testing and Prevalence of the Resistance Mutations: A Literature Review.

Human cytomegalovirus (HCMV) is a pathogen with high prevalence in the general population that is responsible for high morbidity and mortality in immunocompromised individuals and newborns, while remaining mainly asymptomatic in healthy individuals. The HCMV genome is 236,000 nucleotides long and encodes approximately 200 genes in more than 170 open reading frames, with the highest rate of genetic polymorphisms occurring in the envelope glycoproteins. HCMV infection is treated with antiviral drugs such as ganciclovir, valganciclovir, cidofovir, foscarnet, letermovir and maribavir targeting viral enzymes, DNA polymerase, kinase and the terminase complex. One of the obstacles to successful therapy is the emergence of drug resistance, which can be tested phenotypically or by genotyping using Sanger sequencing, which is a widely available but less sensitive method, or next-generation sequencing performed in samples with a lower viral load to detect minority variants, those representing approximately 1% of the population. The prevalence of drug resistance depends on the population tested, as well as the drug, and ranges from no mutations detected to up to almost 50%. A high prevalence of resistance emphasizes the importance of testing the patient whenever resistance is suspected, which requires the development of more sensitive and rapid tests while also highlighting the need for alternative therapeutic targets, strategies and the development of an effective vaccine.

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.

Quantification of Antiviral Cytokines in Serum, Cerebrospinal Fluid and Urine of Patients with Tick-Borne Encephalitis in Croatia.

BACKGROUND: Tick-borne encephalitis virus (TBEV) is one of the most significant arboviruses affecting the human central nervous system (CNS) in Europe. Data on cytokine response in TBEV infection are limited. METHODS: We analyzed the cytokine response in serum, cerebrospinal fluid (CSF) and urine samples of patients with TBE. The control group consisted of patients with 'febrile headache' who had normal CSF cytology. The panel included 12 cytokines: TNF-α, IL-6, Th1 (IL-2, IFN-γ), Th2 (IL-4, IL-5, IL-13), Th9 (IL-9), Th17 (IL-17A, IL-17F), Th22 (IL-22) cytokines and IL-10. RESULTS: TBE patients were more likely to have increased levels of IL-6 and IFN-γ in CSF compared to controls (85.7% vs. 58.8% and 85.7% vs. 47.1%, respectively). However, concentrations of IL-6 (the most abundant cytokine in the CSF of both groups), IL-10 and IL-9 were lower in TBEV patients compared with controls, but the difference was statistically significant for IL-9 only (p = 0.001). By analyzing the cytokine levels in different clinical samples, all measured cytokines were detected in the serum, with the highest concentrations found for IFN-γ, TNF-α, IL-10, IL-17F and IL-22. Higher concentrations of cytokines in the CSF compared with serum were observed for IL-5, IL-6 and IL-22. All cytokines except IL-13 were detectable in urine but in a small proportion of patients, except for IL-22, which was detectable in 95.8% of patients. CONCLUSIONS: Cytokine composition in different clinical samples of TBE patients reveals a different network of early innate immune response cytokines, Th1, Th2, Th9, Th22, Th17 and anti-inflammatory cytokines.

Severe West Nile Virus Neuroinvasive Disease: Clinical Characteristics, Short- and Long-Term Outcomes.

West Nile Virus Neuroinvasive Disease (WNV NID) requires prolonged intensive care treatment, resulting in high mortality and early disability. Long-term results are lacking. We have conducted an observational retrospective study with a prospective follow-up of WNV NID patients treated at the Intensive Care Unit (ICU), University Hospital for Infectious Diseases, Zagreb, Croatia, 2013-2018. Short-term outcomes were vital status, length of stay (LOS), modified Rankin Scale (mRS), and disposition at discharge. Long-term outcomes were vital status and mRS at follow-up. Twenty-three patients were identified, 78.3% males, median age 72 (range 33-84) years. Two patients (8.7%) died in the ICU, with no lethal outcomes after ICU discharge. The median ICU LOS was 19 days (range 5-73), and the median hospital LOS was 34 days (range 7-97). At discharge, 15 (65.2%) patients had moderate to severe/mRS 3-5, 6 (26.0%) had slight disability/mRS 2-1, no patients were symptom-free/mRS 0. Ten (47.6%) survivors were discharged to rehabilitation facilities. The median time to follow-up was nine months (range 6-69). At follow-up, seven patients died (30.5%), five (21.7%) had moderate to severe/mRS 3-5, one (4.3%) had slight disability/mRS 2-1, six (26.1%) had no symptoms/mRS 0, and four (17.4%) were lost to follow-up. Briefly, ten (43.5%) survivors improved their functional status, one (4.3%) was unaltered, and one (4.3%) aggravated. In patients with severe WNV NID, intensive treatment in the acute phase followed by inpatient rehabilitation resulted in significant recovery of functional status after several months.

Antiviral Cytokine Response in Neuroinvasive and Non-Neuroinvasive West Nile Virus Infection.

Data on the immune response to West Nile virus (WNV) are limited. We analyzed the antiviral cytokine response in serum and cerebrospinal fluid (CSF) samples of patients with WNV fever and WNV neuroinvasive disease using a multiplex bead-based assay for the simultaneous quantification of 13 human cytokines. The panel included cytokines associated with innate and early pro-inflammatory immune responses (TNF-α/IL-6), Th1 (IL-2/IFN-γ), Th2 (IL-4/IL-5/IL-9/IL-13), Th17 immune response (IL-17A/IL-17F/IL-21/IL-22) and the key anti-inflammatory cytokine IL-10. Elevated levels of IFN-γ were detected in 71.7% of CSF and 22.7% of serum samples (p = 0.003). Expression of IL-2/IL-4/TNF-α and Th1 17 cytokines (IL-17A/IL-17F/IL-21) was detected in the serum but not in the CSF (except one positive CSF sample for IL-17F/IL-4). While IL-6 levels were markedly higher in the CSF compared to serum (CSF median 2036.71, IQR 213.82-6190.50; serum median 24.48, IQR 11.93-49.81; p < 0.001), no difference in the IL-13/IL-9/IL-10/IFN-γ/IL-22 levels in serum/CSF was found. In conclusion, increased concentrations of the key cytokines associated with innate and early acute phase responses (IL-6) and Th1 type immune responses (IFN-γ) were found in the CNS of patients with WNV infection. In contrast, expression of the key T-cell growth factor IL-2, Th17 cytokines, a Th2 cytokine IL-4 and the proinflammatory cytokine TNF-α appear to be concentrated mainly in the periphery.

Clinical, Virological, and Immunological Findings in Patients with Toscana Neuroinvasive Disease in Croatia: Report of Three Cases.

Toscana virus (TOSV) is an arthropod-borne virus, transmitted to humans by phlebotomine sandflies. Although the majority of infections are asymptomatic, neuroinvasive disease may occur. We report three cases of neuroinvasive TOSV infection detected in Croatia. Two patients aged 21 and 54 years presented with meningitis, while a 22-year old patient presented with meningoencephalitis and right-sided brachial plexitis. Cerebrospinal fluid (CSF), serum, and urine samples were collected and tested for neuroinvasive arboviruses: tick-borne encephalitis, West Nile, Usutu, TOSV, Tahyna, and Bhanja virus. In addition, CSF and serum samples were tested for the anti-viral cytokine response. High titers of TOSV IgM (1000-3200) and IgG (3200-10,000) antibodies in serum samples confirmed TOSV infection. Antibodies to other phleboviruses (sandfly fever Sicilian/Naples/Cyprus virus) were negative. CSF samples showed high concentrations of interleukin 6 (IL-6; range 162.32-2683.90 pg/mL), interferon gamma (IFN-γ; range 110.12-1568.07 pg/mL), and IL-10 (range 28.08-858.91 pg/mL), while significantly lower cytokine production was observed in serum. Two patients recovered fully. The patient with a brachial plexitis improved significantly at discharge. The presented cases highlight the need of increasing awareness of a TOSV as a possible cause of aseptic meningitis/meningoencephalitis during summer months. Association of TOSV and brachial plexitis with long-term sequelae detected in one patient indicates the possibility of more severe disease, even in young patients.

The association of semaphorins 3C, 5A and 6D with liver fibrosis stage in chronic hepatitis C.

Semaphorins are a diverse family of immunoregulators recently recognized to play a major role in various phases of immune responses. Their role in chronic viral hepatitis C (CHC) and contribution to the progression of liver disease is unknown. The aim of this study was to analyse the association of secreted semaphorins with the severity of liver disease in patients with CHC. Serum concentrations of semaphorins were measured in 114 treatment-naive CHC patients and 36 healthy controls. Serum concentrations of SEMA3A, SEMA3C, SEMA5A, SEMA6B and SEMA6D were significantly increased in patients with CHC compared to controls. While serum concentrations of SEMA3C and SEMA6D significantly increased with fibrosis stage in both HCV-g1 and HCV-g3 infections, the concentration of SEMA5A inversely correlated with fibrosis stage in both HCV genotypes. ROC analysis showed that serum concentrations of SEMA3C (>4.0ng/mL, AUC 0.88) and SEMA6D (>4.5, AUC 0.82) had higher AUC than widely used APRI (AUC 0.71) and FIB-4 (AUC 0.74) scores. Serum concentrations of SEMA3C and SEMA6D significantly decreased after DAA and PEG IFN-α/ribavirin therapy, while the serum concentration of SEMA5A significantly increased after DAAs therapy. Immunohistochemistry confirmed the expression of SEMA3C and SEMA5A in hepatocytes, endothelial cells and lymphocytes of cirrhotic livers from CHC patients but not in controls. In conclusion, we provide the first evidence that SEMA3C, SEMA5A and SEMA6D can be considered as markers of liver injury in CHC.

Chemokines CXCL10, CXCL11, and CXCL13 in acute disseminated encephalomyelitis, non-polio enterovirus aseptic meningitis, and neuroborreliosis: CXCL10 as initial discriminator in diagnostic algorithm?

We investigated potential diagnostic usefulness of serum and cerebrospinal fluid (CSF) concentrations of chemokines CXCL10, CXCL11, and CXCL13 in pediatric patients with acute disseminated encephalomyelitis (ADEM) (n = 23), non-polio enterovirus aseptic meningitis (NPEV AM) (n = 20), and neuroborreliosis (NB) (n = 21) and children with acute infectious diseases with neurological symptoms but with excluded neuroinfection/neuroinflammation (controls, n = 20). CSF levels of CXCL10 and CXCL11 were higher in patients with NPEV AM than those in other children, and CXCL10 levels showed a high discriminative potential (area under the receiver operating characteristic curve, ROC, 0.982) with high specificity and sensitivity (both 95%). CSF levels of CXCL13 were higher in NB patients than those in other children; however, discriminative potential (area under ROC curve 0.814) and diagnostic properties were moderate (sensitivity 67%, specificity 97%). Data suggest usefulness of chemokine quantification as a diagnostic aid in children with suspected ADEM, NPEV AM, or NB.

The comparison of Th1, Th2, Th9, Th17 and Th22 cytokine profiles in acute and chronic HIV-1 infection.

The aim of this study was to compare cytokine expression on both gene and protein levels in acute and chronic phase of HIV type 1 (HIV-1) infection. Thirty four patients were enrolled for cytokine expression analysis on protein level in acute and chronic stage of HIV-1 infection. Using PCR array technology, expression of 84 cytokine genes was measured in 3 patients in acute and 3 patients in chronic stage of HIV-1 infection. Bead-based cytometry was used to quantify levels of Th1/Th2/Th9/Th17/Th22 cytokines. The results showed statistically significant increase of 13 cytokine gene expression (cd40lg, csf2, ifna5, il12b, il1b, il20, lta, osm, spp1, tgfa, tnfsf 11, 14 and 8) and downregulation of the il12a expression in chronic HIV type 1 infection. Concentrations of IL-10, IL-4 and TNF-α were increased in the acute HIV type 1 infection when compared to control group. During chronic HIV type 1 infection there was an increase of IL-10, TNF-α, IL-2, IL-6, IL-13 and IL-22 levels when compared to control group. Comparison of cytokine expression between two stages of infection showed a significant decrease in IL-9 concentration. This study showed changes in cytokine profiles on both gene and protein levels in different stages of HIV-infection.

Cardiovascular markers of inflammation and serum lipid levels in HIV-infected patients with undetectable viraemia.

INTRODUCTION: Successfully treated HIV-infected patients may still have an increased risk for cardiovascular morbidity and mortality, which might be related not only to traditional risks, but also to inflammation and dyslipidemia induced by HIV and/or antiretroviral therapy [1, 2]. We examined the relationship of serum lipid levels with plasma biomarkers of inflammation using a composite inflammatory burden score (IBS) from the following seven markers of inflammation: CD40L, tPA, MCP-1, IL-8, IL-6, hCRP and P-selectin. MATERIALS AND METHODS: Subjects were selected among consecutive HIV-infected males ≥18 years of age with an undetectable viral load (<50 copies/mL of HIV1-RNA), seen at the University Hospital for Infectious Diseases, Zagreb, Croatia, in the period from January 2012 to March 2013. Plasma inflammatory biomarkers (CD40L, tPA, MCP-1, IL-8, IL-6, hCRP and P-selectin, quantified by bead-based cytometry) >75th percentile were considered elevated and an IBS was constructed as the presence of zero, one, two, or three or more elevated biomarkers. Correlations between the IBS and lipid parameters were examined using Spearman's Rho and by ordered logistic regression proportional odds model to estimate the odds of more elevated (>75th percentile) biomarkers. RESULTS: 181 male patients were included into the study, the median age was 46.7 (Q1-Q3, 39.9-55.0) years and the median current CD4 cell count was 553.0 (Q1-Q3, 389-729) per microliter. The patients were mainly treated with two nucleoside reverse transcriptase inhibitor (NRTI) plus one non-NRTI (NNRTI) (N=100, 60.8%) or two NRTI plus lopinavir (N=50, 27.6%). There was a significant correlation between the IBS and serum cholesterol (Rho=0.23, 95% CI, 0.09-0.37), triglycerides (Rho=0.30, 95% CI, 0.16-0.42) and cholesterol/HDL-cholesterol ratio (Rho=0.25, 95% CI 0.11-0.38). In the multivariable model a one unit increase in cholesterol/HDL-cholesterol ratio was associated with a 1.72-fold (95% CI, 1.27-2.33) increased odds of having a greater IBS. One unit increase (mmol/L) of cholesterol and triglycerides was associated with a 1.41-fold (95% CI, 1.13-1.76) and 1.37-fold (95% CI, 1.18-1.60) increased odds of having a greater IBS, respectively. CONCLUSIONS: Our study suggests that in virologically suppressed patients there is a significant association between markers of inflammation and serum levels of cholesterol and triglycerides as well as the cholesterol/HDL-cholesterol ratio.

Chemokine CXCL10 at week 4 of treatment predicts sustained virological response in patients with chronic hepatitis C.

The aim of this study was to analyze the predictive value of CXCL9, CXCL10, and CXCL11 concentrations before and after 4 and 12 weeks of treatment with pegylated interferon-α2b and ribavirin in patients with chronic hepatitis C infected with the hepatitis C virus genotype 1. The study included 46 adult patients (29 women and 17 men). Chemokine quantification in the serum was performed at baseline and after 1, 3, and 6 months of treatment by enzyme immunoassay. Chemokine responses were compared in patients achieving a sustained virological response to treatment (SVR, n=26) and the non-SVR group (n=20). The differences in the CXCL9 and CXCL10 concentrations between the SVR and non-SVR groups were statistically significant. A multivariant analysis showed a significant association between treatment failure and higher concentrations of CXCL10. A higher predictive value of CXCL10 concentrations after 4 weeks of treatment compared to pretreatment values has been found (area under the curve 0.9288 and 0.7942, respectively, P=0.016). CXCL10 concentrations above 250 pg/mL 4 weeks after the start of treatment were independently associated with non-SVR. In conclusion, the results of this study have shown that CXCL10 concentrations at the time of a rapid viral response (4 weeks) are better predictors of achieving SVR compared to baseline levels. Additionally, this study suggests an important role of CXCL9 as a biomarker of SVR in patients with chronic hepatitis C.

Concentration gradient of CXCL10 and CXCL11 between the cerebrospinal fluid and plasma in children with enteroviral aseptic meningitis.

BACKGROUND: Lymphocyte migration from the blood into the CNS is mediated by chemokines and chemokine receptors. Chemokines CXCL10 and CXCL11 are important for the recruitment of CXCR3-expressing Th1 lymphocytes to the site of inflammation. AIMS: To determine the concentrations of CXCL10 and CXCL11 in the CSF and plasma of children with enteroviral aseptic meningitis (EV AM) and controls and the contribution of these chemokines to the chemokine concentration gradient between the periphery and the CNS. METHODS: The study included 26 pediatric patients with EV AM and 16 controls in whom CNS infection is excluded by negative CSF examination. Chemokines were quantified by using enzyme immunoassay. Etiological diagnosis of EV AM was based on the detection of enteroviral RNA in the CSF using real-time PCR. RESULTS: CXCL10 (median 12 725 pg/ml) and CXCL11 (median 187 pg/ml) concentrations in CSF of patients with meningitis were significantly higher compared to plasma (median 173 pg/ml and median 110 pg/ml; p < 0.001, p = 0.026 respectively). CXCL10 concentrations in the CSF (median 198 pg/ml) and plasma of controls (median 124 pg/ml) were not significantly different (p = 0.642). CXCL11 concentrations in the CSF of controls (median 89 pg/ml) were significantly lower compared with plasma (median 139 pg/ml, p = 0.004). Chemokine concentration gradient was not influenced by pleocytosis, nor dependent on cytologic CSF formula or the presence of proteinorrachia. CONCLUSION: CXCL10 and CXCL11 concentration gradient between the CSF and plasma in children with EV AM suggests an important role of these chemokines in the T-cells recruitment into the CNS and local immunoreaction.