Supplementation of vitamin E as an addition to a commercial renal diet does not prolong survival of cats with chronic kidney disease.

BACKGROUND: The aim of this double-blind, placebo-controlled study was to investigate the effect of vitamin E supplementation as an addition to a commercial renal diet on survival time of cats with different stages of chronic kidney disease (CKD). In addition, we were interested whether vitamin E supplementation affects selected oxidative stress and clinical parameters. Thirty-four cats with CKD and 38 healthy cats were included in the study. Cats with CKD were classified according to the IRIS Guidelines; seven in IRIS stage 1, 15 in IRIS stage 2, five in IRIS stage 3 and seven in IRIS stage 4. Cats with CKD were treated according to IRIS Guidelines. Cats with CKD were randomly assigned to receive vitamin E (100 IU/cat/day) or placebo (mineral oil) for 24 weeks in addition to standard therapy. Plasma malondialdehyde (MDA) and protein carbonyl (PC) concentrations, DNA damage of peripheral lymphocytes and plasma vitamin E concentrations were measured at baseline and four, eight, 16 and 24 weeks thereafter. Routine laboratory analyses and assessment of clinical signs were performed at each visit. RESULTS: Vitamin E supplementation had no effect on the survival time and did not reduce the severity of clinical signs. Before vitamin E supplementation, no significant differences in vitamin E, MDA and PC concentrations were found between healthy and CKD cats. However, plasma MDA concentration was statistically significantly higher (p = 0.043) in cats with early CKD (IRIS stages 1 and 2) than in cats with advanced CKD (IRIS stages 3 and 4). Additionally, DNA damage was statistically significantly higher in healthy cats (p ≤ 0.001) than in CKD cats. Plasma vitamin E concentrations increased statistically significantly in the vitamin E group compared to the placebo group four (p = 0.013) and eight (p = 0.017) weeks after the start of vitamin E supplementation. During the study and after 24 weeks of vitamin E supplementation, plasma MDA and PC concentrations and DNA damage remained similar to pre-supplementation levels in both the placebo and vitamin E groups. CONCLUSIONS: Vitamin E supplementation as an addition to standard therapy does not prolong survival in feline CKD.

Initial data analysis for longitudinal studies to build a solid foundation for reproducible analysis.

Initial data analysis (IDA) is the part of the data pipeline that takes place between the end of data retrieval and the beginning of data analysis that addresses the research question. Systematic IDA and clear reporting of the IDA findings is an important step towards reproducible research. A general framework of IDA for observational studies includes data cleaning, data screening, and possible updates of pre-planned statistical analyses. Longitudinal studies, where participants are observed repeatedly over time, pose additional challenges, as they have special features that should be taken into account in the IDA steps before addressing the research question. We propose a systematic approach in longitudinal studies to examine data properties prior to conducting planned statistical analyses. In this paper we focus on the data screening element of IDA, assuming that the research aims are accompanied by an analysis plan, meta-data are well documented, and data cleaning has already been performed. IDA data screening comprises five types of explorations, covering the analysis of participation profiles over time, evaluation of missing data, presentation of univariate and multivariate descriptions, and the depiction of longitudinal aspects. Executing the IDA plan will result in an IDA report to inform data analysts about data properties and possible implications for the analysis plan-another element of the IDA framework. Our framework is illustrated focusing on hand grip strength outcome data from a data collection across several waves in a complex survey. We provide reproducible R code on a public repository, presenting a detailed data screening plan for the investigation of the average rate of age-associated decline of grip strength. With our checklist and reproducible R code we provide data analysts a framework to work with longitudinal data in an informed way, enhancing the reproducibility and validity of their work.

Leave-one-out cross-validation, penalization, and differential bias of some prediction model performance measures-a simulation study.

BACKGROUND: The performance of models for binary outcomes can be described by measures such as the concordance statistic (c-statistic, area under the curve), the discrimination slope, or the Brier score. At internal validation, data resampling techniques, e.g., cross-validation, are frequently employed to correct for optimism in these model performance criteria. Especially with small samples or rare events, leave-one-out cross-validation is a popular choice. METHODS: Using simulations and a real data example, we compared the effect of different resampling techniques on the estimation of c-statistics, discrimination slopes, and Brier scores for three estimators of logistic regression models, including the maximum likelihood and two maximum penalized likelihood estimators. RESULTS: Our simulation study confirms earlier studies reporting that leave-one-out cross-validated c-statistics can be strongly biased towards zero. In addition, our study reveals that this bias is even more pronounced for model estimators shrinking estimated probabilities towards the observed event fraction, such as ridge regression. Leave-one-out cross-validation also provided pessimistic estimates of the discrimination slope but nearly unbiased estimates of the Brier score. CONCLUSIONS: We recommend to use leave-pair-out cross-validation, fivefold cross-validation with repetitions, the enhanced or the .632+ bootstrap to estimate c-statistics, and leave-pair-out or fivefold cross-validation to estimate discrimination slopes.

Statistical analysis of high-dimensional biomedical data: a gentle introduction to analytical goals, common approaches and challenges.

BACKGROUND: In high-dimensional data (HDD) settings, the number of variables associated with each observation is very large. Prominent examples of HDD in biomedical research include omics data with a large number of variables such as many measurements across the genome, proteome, or metabolome, as well as electronic health records data that have large numbers of variables recorded for each patient. The statistical analysis of such data requires knowledge and experience, sometimes of complex methods adapted to the respective research questions. METHODS: Advances in statistical methodology and machine learning methods offer new opportunities for innovative analyses of HDD, but at the same time require a deeper understanding of some fundamental statistical concepts. Topic group TG9 "High-dimensional data" of the STRATOS (STRengthening Analytical Thinking for Observational Studies) initiative provides guidance for the analysis of observational studies, addressing particular statistical challenges and opportunities for the analysis of studies involving HDD. In this overview, we discuss key aspects of HDD analysis to provide a gentle introduction for non-statisticians and for classically trained statisticians with little experience specific to HDD. RESULTS: The paper is organized with respect to subtopics that are most relevant for the analysis of HDD, in particular initial data analysis, exploratory data analysis, multiple testing, and prediction. For each subtopic, main analytical goals in HDD settings are outlined. For each of these goals, basic explanations for some commonly used analysis methods are provided. Situations are identified where traditional statistical methods cannot, or should not, be used in the HDD setting, or where adequate analytic tools are still lacking. Many key references are provided. CONCLUSIONS: This review aims to provide a solid statistical foundation for researchers, including statisticians and non-statisticians, who are new to research with HDD or simply want to better evaluate and understand the results of HDD analyses.

Molecular Typing of Mastadenoviruses in Simultaneously Collected Nasopharyngeal Swabs and Stool Samples from Children Hospitalized for Acute Bronchiolitis, Acute Gastroenteritis, and Febrile Seizures.

This study determines and compares the frequency of human mastadenovirus (HAdV) presence in children with acute bronchiolitis (AB), acute gastroenteritis (AGE), and febrile seizures (FS), ascertains types of HAdVs associated with each individual syndrome and contrasts the findings with a control group of children. The presence of HAdVs was ascertained in simultaneously collected nasopharyngeal (NP) swabs and stool samples amplifying the hexon gene by RT-PCR; these were sequenced to determine the types of HAdVs. HAdVs were grouped into eight different genotypes. Of these, three (F40, F41, and A31) were found solely in stool samples, whereas the others (B3, C1, C2, C5, and C6) were found in both stool samples and NP swabs. The most common genotypes in NP swabs were C2 (found in children with AGE and FS) and C1 (only in children with FS), whereas in stool samples genotypes F41 (in children with AGE) and C2 (in children with AGE and FS) prevailed, and C2 was simultaneously present in both samples. HAdVs were more often detected in stool samples than in NP swabs in patients (with the highest estimated viral load in stool samples in children with AB and AGE) and healthy controls and were more common in NP swabs in children with AGE than in children with AB. In most patients, the characterized genotypes in NP swabs and stool samples were in concordance.

Sex Differences in Age-Associated Rate of Decline in Grip Strength When Engaging in Vigorous Physical Activity.

Handgrip strength (GS) is used as an indicator of overall muscle strength and health outcomes for aging adults. GS has also been evaluated as a potential link with sport performances. We quantified the age-associated decline in grip strength for males and females engaged in weekly vigorous physical activity, differentiated by body mass, and investigated whether there was an acceleration of decline at any age. The Survey of Health, Ageing and Retirement in Europe is a multinational complex panel data survey with a target population of individuals aged 50 years or older. Data from 48,070 individuals from 20 European countries, collected from 2004 to 2015, were used in multivariable regression models to study the association of age and body weight with grip strength for individuals engaged in vigorous physical activity at least once a week. The annual rate of change in GS differed for males and females; it was constant from ages 50 to 55 years and then accelerated for females, possibly due to the menopausal transition. In contrast, the decline in GS accelerates with each year of increase in age for males. Higher body mass was associated with an increase in GS, but the increase was less pronounced for older males. The increase in GS diminished with a body mass above the median even with engagement in weekly vigorous physical activities. GS reference values for individuals engaged in vigorous physical activity add to existing reference values for general populations.

Unique Clinical, Immune, and Genetic Signature in Patients with Borrelial Meningoradiculoneuritis1.

Lyme neuroborreliosis (LNB) in Europe may manifest with painful meningoradiculoneuritis (also known as Bannwarth syndrome) or lymphocytic meningitis with or without cranial neuritis (peripheral facial palsy). We assessed host immune responses and the prevalence of TLR1 (toll-like receptor 1)-1805GG polymorphism to gain insights into the pathophysiology of these conditions. Regardless of LNB manifestation, most mediators associated with innate and adaptive immune responses were concentrated in cerebrospinal fluid; serum levels were unremarkable. When stratified by specific clinical manifestation, patients with meningoradiculoneuritis had higher levels of B-cell chemoattractants CXC motif chemokine ligand (CXCL) 12 and CXCL13 and T-cell-associated mediators CXCL9, CXCL10, and interleukin 17, compared with those without radicular pain. Moreover, these patients had a higher frequency of TLR1-1805GG polymorphism and more constitutional symptoms. These findings demonstrate that meningoradiculoneuritis is a distinct clinical entity with unique immune and genetic pathophysiology, providing new considerations for the study of LNB and borrelial meningoradiculitis.

Organizing and Analyzing Data from the SHARE Study with an Application to Age and Sex Differences in Depressive Symptoms.

The SHARE study contains health, lifestyle, and socioeconomic data from individuals ages 50 and older in European countries collected over several waves. Leveraging these data for research purposes can be daunting due to the complex structure of the longitudinal design. The two aims of our study are (1) to develop a framework and R code for data management of the SHARE data to prepare for data analysis, and (2) to demonstrate how to apply the framework to a specific research question, where the aim is to model the presence of clinically significant depression assessed by the 12-item Europe depression scale. The result is a framework that substantially reduces the time to initiate research studies using SHARE data, facilitating the data extraction, data preparation and initial data analysis, with reproducible R code. Further, we illustrate the extensive work required to prepare an analysis-ready data set to ensure the validity of the modeling results. This underlines the importance of carefully considering and recording data management decisions that have to be built into the research process. The results about sex differences in the probability of depression are consistent with previous literature. Our findings about age-associated changes can be opportunities for adequate treatment interventions.

Upregulated Intrathecal Expression of VEGF-A and Long Lasting Global Upregulation of Proinflammatory Immune Mediators in Vaccine Breakthrough Tick-Borne Encephalitis.

Although anti-TBE vaccines are highly effective, vaccine breakthrough (VBT) cases have been reported. With increasing evidence for immune system involvement in TBE pathogenesis, we characterized the immune mediators reflecting innate and adaptive T and B cell responses in neurological and convalescent phase in VBT TBE patients. At the beginning of the neurological phase, VBT patients have significantly higher serum levels of several innate and adaptive inflammatory cytokines compared to healthy donors, reflecting a global inflammatory state. The majority of cytokines, particularly those associated with innate and Th1 responses, are highly concentrated in CSF and positively correlate with intrathecal immune cell counts, demonstrating the localization of Th1 and proinflammatory responses in CNS, the site of disease in TBE. Interestingly, compared to unvaccinated TBE patients, VBT TBE patients have significantly higher CSF levels of VEGF-A and IFN-ß and higher systemic levels of neutrophil chemoattractants IL-8/CXCL8 and GROα/CXCL1 on admission. Moreover, serum levels of IL-8/CXCL8 and GROα/CXCL1 remain elevated for two months after the onset of neurological symptoms, indicating a prolonged systemic immune activation in VBT patients. These findings provide the first insights into the type of immune responses and their dynamics during TBE in VBT patients. An observed systemic upregulation of neutrophil derived inflammation in acute and convalescent phase of TBE together with highly expressed VEGF-A could contribute to BBB disruption that facilitates the entry of immune cells and supports the intrathecal localization of Th1 responses observed in VBT patients.

Comparison of Clinical, Laboratory and Immune Characteristics of the Monophasic and Biphasic Course of Tick-Borne Encephalitis.

The biphasic course of tick-borne encephalitis (TBE) is well described, but information on the monophasic course is limited. We assessed and compared the clinical presentation, laboratory findings, and immune responses in 705 adult TBE patients: 283 with monophasic and 422 with biphasic course. Patients with the monophasic course were significantly (p ≤ 0.002) older (57 vs. 50 years), more often vaccinated against TBE (7.4% vs. 0.9%), more often had comorbidities (52% vs. 37%), and were more often treated in the intensive care unit (12.4% vs. 5.2%). Multivariate logistic regression found strong association between the monophasic TBE course and previous TBE vaccination (OR = 18.45), presence of underlying illness (OR = 1.85), duration of neurologic involvement before cerebrospinal fluid (CSF) examination (OR = 1.39), and patients' age (OR = 1.02). Furthermore, patients with monophasic TBE had higher CSF levels of immune mediators associated with innate and adaptive (Th1 and B-cell) immune responses, and they had more pronounced disruption of the blood-brain barrier. However, the long-term outcome 2-7 years after TBE was comparable. In summary, the monophasic course is a frequent and distinct presentation of TBE that is associated with more difficult disease course and higher levels of inflammatory mediators in CSF than the biphasic course; however, the long-term outcome is similar.

Low Virus-Specific IgG Antibodies in Adverse Clinical Course and Outcome of Tick-Borne Encephalitis.

Tick-borne encephalitis (TBE) is associated with a range of disease severity. The reasons for this heterogeneity are not clear. Levels of serum IgG antibodies to TBE virus (TBEV) were determined in 691 adult patients during the meningoencephalitic phase of TBE and correlated with detailed clinical and laboratory parameters during acute illness and with the presence of post-encephalitic syndrome (PES) 2-7 years after TBE. Specific IgG antibody levels ranged from below cut-off value (in 32/691 patients, 4.6%), to 896 U/mL (median = 37.3 U/mL). Patients with meningoencephalomyelitis were more often seronegative (24.3%; 9/37) than those with meningoencephalitis (4.7%; 20/428) or meningitis (1.3%; 3/226). Moreover, patients with antibody levels below cut-off had longer hospitalization (13 versus 8 days); more often required intensive care unit treatment (22% versus 8%) and artificial ventilation (71% versus 21%); and had a higher fatality rate (3/32; 9.4% versus 1/659; 0.2%) than seropositive patients. These results were confirmed when antibody levels, rather than cut-off values, were correlated with clinical parameters including the likelihood to develop PES. Low serum IgG antibody responses against TBEV at the onset of neurologic involvement are associated with a more difficult clinical course and unfavorable long-term outcome of TBE, providing a diagnostic and clinical challenge for physicians.

Restricted cubic splines for modelling periodic data.

In regression modelling the non-linear relationships between explanatory variables and outcome are often effectively modelled using restricted cubic splines (RCS). We focus on situations where the values of the outcome change periodically over time and we define an extension of RCS that considers periodicity by introducing numerical constraints. Practical examples include the estimation of seasonal variations, a common aim in virological research, or the study of hormonal fluctuations within menstrual cycle. Using real and simulated data with binary outcomes we show that periodic RCS can perform better than other methods proposed for periodic data. They greatly reduce the variability of the estimates obtained at the extremes of the period compared to cubic spline methods and require the estimation of fewer parameters; cosinor models perform similarly to the best cubic spline model and their estimates are generally less variable, but only if an appropriate number of harmonics is used. Periodic RCS provide a useful extension of RCS for periodic data when the assumption of equality of the outcome at the beginning and end of the period is scientifically sensible. The implementation of periodic RCS is freely available in peRiodiCS R package and the paper presents examples of their usage for the modelling of the seasonal occurrence of the viruses.

Course and Outcome of Erythema Migrans in Pregnant Women.

Information on Lyme borreliosis (LB) during pregnancy is limited. In the present study, the course and outcome of erythema migrans (EM) in 304 pregnant women, diagnosed in the period 1990-2015, was assessed and compared with that in age-matched non-pregnant women. The frequency of unfavorable outcome of pregnancies was also evaluated. The pregnant women reported constitutional symptoms less frequently than the non-pregnant women (22.4% vs. 37.2%, p < 0.001). Pregnant women diagnosed with EM later during pregnancy had a lower probability of reporting constitutional symptoms (odds ratio = 0.97 for 1-week difference in gestation week at diagnosis of EM, 95% CI: 0.94-0.99, p = 0.02). The outcome of pregnancy was unfavorable in 42/304 (13.8%) patients: preterm birth in 22/42 (52.4%), fetal/perinatal death in 10/42 (23.8%), and/or anomalies in 15/42 (35.7%). Several patients had potential explanation(s) for the unfavorable outcome. In conclusion, the course of early LB during pregnancy is milder than in age-matched non-pregnant women. The outcome of pregnancy with the treatment approach used in the present study (i.v. ceftriaxone 2 g once daily for 14 days) is favorable.

Hidden analyses: a review of reporting practice and recommendations for more transparent reporting of initial data analyses.

BACKGROUND: In the data pipeline from the data collection process to the planned statistical analyses, initial data analysis (IDA) typically takes place between the end of the data collection and do not touch the research questions. A systematic process for IDA and clear reporting of the findings would help to understand the potential shortcomings of a dataset, such as missing values, or subgroups with small sample sizes, or shortcomings in the collection process, and to evaluate the impact of these shortcomings on the research results. A clear reporting of findings is also relevant when making datasets available to other researchers. Initial data analyses can provide valuable insights into the suitability of a data set for a future research study. Our aim was to describe the practice of reporting of initial data analyses in observational studies in five highly ranked medical journals with focus on data cleaning, screening, and reporting of findings which led to a potential change in the analysis plan. METHODS: This review was carried out using systematic search strategies with eligibility criteria for articles to be reviewed. A total of 25 papers about observational studies were selected from five medical journals published in 2018. Each paper was reviewed by two reviewers and IDA statements were further discussed by all authors. The consensus was reported. RESULTS: IDA statements were reported in the methods, results, discussion, and supplement of papers. Ten out of 25 papers (40%) included a statement about data cleaning. Data screening statements were included in all articles, and 18 (72%) indicated the methods used to describe them. Item missingness was reported in 11 papers (44%), unit missingness in 15 papers (60%). Eleven papers (44%) mentioned some changes in the analysis plan. Reported changes referred to missing data treatment, unexpected values, population heterogeneity and aspects related to variable distributions or data properties. CONCLUSION: Reporting of initial data analyses were sparse, and statements on IDA were located throughout the research articles. There is a lack of systematic reporting of IDA. We conclude the article with recommendations on how to overcome shortcomings in the practice of IDA reporting in observational studies.

Detection of herpes simplex and varicella-zoster virus from skin lesions: comparison of RT-PCR and isothermal amplification for rapid identification.

We compared 2 molecular tests for detection of herpes simplex viruses 1 and 2 (HSV-1, HSV-2) and varicella-zoster virus (VZV): real-time polymerase chain reaction (RT-PCR) (Argene, BioMerieux, France) performed on an LC480 platform (Roche Applied Science, Mannheim, Germany) and isothermal amplification using a Solana HSV1 + 2/VZV assay (Quidel Corporation Worldwide Headquarters, San Diego, CA) with helicase-dependent amplification performed by a Solana® instrument. With both methods, HSV-1 was detected in 68/291 (23.4%), HSV-2 in 23/291 (7.9%), and VZV in 48/291 (16.5%) skin lesions. Both methods agreed completely only in detection of HSV-2 (kappa = 1). Concordance between Solana HSV1 + 2/VZV and RT-PCR was 98.3% (kappa = 0.95) for HSV-1 and 99.3% (kappa = 0.98) for VZV. Rapid detection of HSV-1, HSV-2, and VZV using the Solana platform is a useful method for routine diagnostics and for urgent swab samples requiring a short turnaround time.

Classification of weekly provincial overall age- and gender-specific mortality patterns during the COVID-19 epidemics in Italy.

OBJECTIVES: to provide a time-varying classification of the Italian provinces based on the weekly age- and gender-specific relative risks (RR) for overall mortality, obtained comparing the number of deaths from 13 weeks from the beginning of the COVID-19 epidemics, with the average number of deaths from the same period in 2015-19. DESIGN: population overall mortality data provided by the Italian National Statistical Office (Istat). SETTING AND PARTICIPANTS: Italian residents 60 years or older from 7,357/7,904 Italian municipalities. For the included municipalities, the number of deaths from any cause from 1 January to 30 May 2020 was available for each day of the 2015-2020 period. Data were stratified by gender, 4 age categories (60-69, 70-79, 80-89, 90+), week, and province. MAIN OUTCOME MEASURES: province- and gender-specific weekly RR curves (age category vs RR), obtained for 13 weeks between 26 February and 26 May; excess mortality; time-varying/weekly classification of provinces. RESULTS: these results provide a weekly classification of the Italian provinces based on their RR curves in 5 groups, 2 of which had high and very high excess mortality during the epidemics. Most of the provinces that appeared at least once in the highest-risk group are neighbouring provinces in the Northern Regions of Lombardy, Emilia-Romagna, Piedmont, and Marche (in central Italy), where most of the COVID-19 cases and deaths were identified. Temporally, most of these provinces remained in the highest-risk group for 4 or 5 weeks; those that entered the group later, improved faster. The overall RR curves for groups differed in magnitude, but also in the shape, which varied markedly also between men and women and, most importantly, in the highest-risk group. CONCLUSIONS: this study gives timely re-analysis of the Istat data at weekly level and provides a classification of the geographical and temporal characteristics of the excess mortality in the Italian provinces during the COVID-19 epidemics. As expected, the used clustering method groups the provinces that have similar RR values in the two gender-specific curves. The results facilitate the presentation of the spatio-temporal mortality patterns of the epidemics and provide evidence of high heterogeneity in the group of provinces that were defined as high-risk groups by others, based on their geographical position or on the time of the observed spread of the virus.

Identifying the Italian provinces with increased mortality during COVID-19 epidemics using the data made available by the Italian National Institute of Statistics. A methodological challenge.

OBJECTIVES: to identify the Italian provinces with excess mortality during the COVID-19 epidemics using the mortality data provided in April 2020 by the Italian National Institute of Statistics (Istat) that, by design, included only the municipalities with at least 20% mortality increase compared to the same period in 2015-19. Inference with the aim to identify increased mortality at provincial level was a very important task when the Istat data were released in April, but the naïve aggregation of the selected municipalities was not sensible to due to the selection criteria of the municipalities used by Istat. DESIGN: use of a permutation-based approach to identify the Italian provinces with excess mortality during the first month of the COVID-19 epidemics using the data made available from Istat and taking into account the biased inclusion criteria. SETTING AND PARTICIPANTS: the number of deaths from any cause from 1 January was available for each year of the 2015-2020 period. Data were stratified by municipality, sex and 21 age categories. The third data release (R3) included 1,686 of the 7,904 Italian municipalities with increased mortality in 2020, covering about 40% of the Italian population. Results were compared with those obtainable with the fifth data release (R5), made available in June, when the selection of the municipalities was no longer based on increased mortality and which included more than 90% of the Italian population. R5 was considered the gold standard. MAIN OUTCOME MEASURES: excess of deaths from any cause in the Italian provinces between 1 March and 4 April; relative risk (RR); permutation p-values; permutation-based adjusted relative risk; population coverage. RESULTS: the results of this study, which are based on two different test statistics, identify 17 and 33 provinces (out of 103) with increased overall mortality, respectively, controlling the family-wise error rate at 0.05 level. Most of the identified provinces are neighbouring provinces in the northern regions of Lombardy, Emilia-Romagna, Piedmont, Liguria, Marche and Tuscany, where most of the COVID-19 cases and deaths were identified. The comparison with data from R5 shows that all the identified provinces had an increase in overall mortality, mostly (31/34) above 25%. On average, the adjusted RR slightly underestimates the RR from R5, underestimating the large RR and overestimating the small RR. CONCLUSIONS: this was, to the best of the authors' knowledge, the first attempt to aggregate the Istat data at province level and obtain a reliable and generalizable statistical inference. This permutation-based approach provides a feasible approach to take into account the selection bias that was present in the data and could be used for analysing other types of data that present some type of selection bias.

Inflammatory Immune Responses in Patients with Tick-Borne Encephalitis: Dynamics and Association with the Outcome of the Disease.

Information on the association of inflammatory immune responses and disease outcome after tick-borne encephalitis (TBE) is limited. In the present study, we assessed the levels of 24 cytokines/chemokines associated with innate and adaptive immune responses in matched serum and cerebrospinal fluid (CSF) samples of 81 patients at first visit, and in serum at follow-up time points. Serum levels of several cytokines/chemokines obtained during the meningoencephalitic phase of TBE differed compared to the levels at a follow-up visit 2 months later; several significant differences were also found in cytokine/chemokine levels in serum at 2 months compared to the last time point, 2-7 years after acute illness. Cytokines/chemokines levels in CSF or serum obtained at the time of acute illness or serum levels obtained 2 months after the onset of TBE did not have predictive value for an unfavorable outcome 2-7 years later. In contrast, serum levels of mediators associated with Th17 responses were lower in patients with unfavorable outcome whereas those associated with other adaptive or innate immune responses were higher at the last visit in those with an unfavorable outcome. These findings provide new insights into the immunopathogenesis of TBE and implicate inflammatory immune responses with post-encephalitic syndrome years after the initial infection.

Inflammatory Immune Responses in the Pathogenesis of Tick-Borne Encephalitis.

Clinical manifestations of tick-borne encephalitis (TBE) are thought to result from the host immune responses to infection, but knowledge of such responses is incomplete. We performed a detailed clinical evaluation and characterization of innate and adaptive inflammatory immune responses in matched serum and cerebrospinal fluid (CSF) samples from 81 adult patients with TBE. Immune responses were then correlated with laboratory and clinical findings. The inflammatory immune responses were generally site-specific. Cytokines and chemokines associated with innate and Th1 adaptive immune responses were significantly higher in CSF, while mediators associated with Th17 and B-cell responses were generally higher in serum. Furthermore, mediators associated with innate and Th1 adaptive immune responses were positively associated with disease severity, whereas Th17 and B cell immune responses were not. During the meningoencephalitic phase of TBE, innate and Th1 adaptive inflammatory mediators were highly concentrated in CSF, the site of the disease. The consequence of this robust immune response was more severe acute illness. In contrast, inflammatory mediators associated with B cell and particularly Th17 responses were concentrated in serum. These findings provide new insights into the immunopathogenesis of TBE and implicate innate and Th1 adaptive responses in severity and clinical presentation of acute illness.