Impact of pre-existing treatment with statins on the course and outcome of tick-borne encephalitis

Lipid-targeting antiviral strategies: Current state and future perspectives

There is an urgent need for antiviral compounds effective against currently known and future viral threats. The development of host-targeting antivirals (HTAs) appears as an alternative strategy to fight viral infections minimizing the potential of resistant mutant development and potentially leading to the identification of broad-spectrum antiviral agents. Among the host factors explored for HTA strategy, lipids constitute an attractive target as many viruses, even genetically diverse, hijack specific lipids during their lifecycle. Multiple repurposing efforts have been performed to analyze the antiviral properties of lipid-targeting compounds. These studies include the analysis of the effects of cholesterol lowering drugs such as statins, cholesterol transport inhibitors, sphingolipid modulators, de novo lipogenesis inhibitors blocking fatty acid synthesis, compounds targeting glycerophospholipids or drugs interfering with lipid droplet metabolism. This review is focused on the current status of lipid-based or lipid-targeting antiviral strategies and their potential for the development of antiviral therapies, with special emphasis on those studies that have reached advanced stages of development such as efficacy studies in animal models or clinical trials. Whereas there is still a long way to go, multiple proof-of-concept studies and clinical evidence reinforce the therapeutic potential of these strategies warranting their further development into effective antiviral therapies.

Do Statins Affect Viral Infections Encountered by International Travelers?

Statins are among the most frequently prescribed medications. In addition to their well-established effectiveness in lowering total cholesterol, LDL, and triglycerides, statins have been described to have immunomodulatory and anti-inflammatory properties and have been associated with improved endothelial functions. Given the common use of statins, we sought to evaluate the effect of statins on some viral infections encountered by residents in tropical areas or by international travelers. A literature search was performed in PubMED/MEDLINE focusing on keywords that included statins and the viruses of interest, including SARS-CoV-2, influenza, yellow fever, dengue, Zika, tick-borne encephalitis, hemorrhagic fever viruses, hepatitis A, norovirus, hepatitis B, hepatitis C, measles, and herpesviruses; findings were synthesized for each virus into a summary. The effects of statins on viral infections vary depending on the specific virus. While some studies indicate potential benefits in chronic HBV and HCV infections, evidence regarding SARS-CoV-2 and influenza remains inconclusive due to mixed findings from observational studies and randomized controlled trials. The role of statins in other viral infections is largely unexplored, with preclinical data available for only a few viruses. Given the conflicting evidence, further prospective studies and randomized controlled trials are warranted to elucidate statins' role in viral infections, particularly in modulating inflammation, endothelial dysfunction, and immune responses. Future research should aim to define the optimal patient populations, target viruses, statin types, and treatment durations that may confer benefits in specific viral infections.

Clinical manifestations and outcomes of Tick-borne encephalitis: A systematic literature review

Tick-borne encephalitis (TBE) is caused by a viral infection and can lead to acute and persistent damage to the central and peripheral nervous systems. Recently, the incidence of TBE in Europe has risen, and epidemiological patterns of disease have changed, emphasising the need for improved understanding of this vaccine-preventable disease. Although TBE is endemic in many countries, the disease spectrum of TBE is not well described. We sought to characterise the clinical manifestations and outcomes of TBE by estimating the proportions of TBE patients with each type of manifestation and the risk of adverse outcomes for children and adults separately. A systematic literature review was conducted on 2 August 2022 for articles published in any language since 1 January 2007. Additional relevant studies were found in reference lists of identified articles. The review was limited to countries where only the European subtype of TBEV circulates. Of the 1,632 unique titles and abstracts identified and reviewed, 21 were retained for data analysis. The 21 studies were split into a main analysis (15 studies reporting patients hospitalised with laboratory-confirmed TBE) and a secondary analysis (6 studies reporting hospitalised and non-hospitalised patients who sought medical treatment for laboratory-confirmed TBE). The main analysis included 5,012 adults and 640 children. The predominant clinical manifestation in adults was encephalitis (61 %), followed by meningitis (33 %), radiculitis (14 %), and myelitis (6 %) (the manifestations were evaluated independently, so they will not sum to 100 %). With outliers removed, similar proportions of adults had encephalitis (48 %) and meningitis (44 %). Among cases in children, meningitis (77 %) was the most common manifestation, whereas encephalitis (23 %) and myelitis (1.3 %) were less frequent. Among hospitalised patients with TBE, the proportion of intensive care unit (ICU) admissions and deaths were similar for adults (15.5 % and 0.9 %, respectively) and children (16.4 % and 0 %, respectively.) The percentage of patients with sequelae when examined >12 months from acute TBE was 39.5 % for adults and 16.2 % for children. The evidence was challenging to aggregate due to study heterogeneity, variability in categorising clinical manifestations of central nervous system disease, variability of denominator populations, and differences in healthcare systems and diagnostic practices across countries. Our study disclosed distinct patterns of clinical manifestation among hospitalised adult and child patients with TBE and a high proportion of ICU admissions and long-term neurological sequelae across both age groups. These findings reinforce the continued need for preventive measures in the populations at risk. Moreover, variability of study admission criteria, including difficulty with clinical manifestation categorisation, calls for a more standardised approach to summarising TBE manifestations and outcomes across Europe.

New Approaches to the Prevention and Treatment of Viral Diseases

The review discusses a new approach to the prevention and treatment of viral infections based on the use of pine needles polyprenyl phosphate (PPP) and associated with the infringement of prenylation process-the attachment of farnesol or geranyl geraniol to the viral protein. Currently, prenylation has been detected in type 1 adenovirus, hepatitis C virus, several herpes viruses, influenza virus, HIV. However, this list is far from complete, given that prenylated proteins play an extremely important role in the activity of the virus. We assume that the interferon produced in response to PPP may suppress expression of the SREBP2 transcription factor. As a result, the mevalonic acid pathway is violated and, as a result, the formation of early polyprenols precursors (geraniol, geranyl geraniol, farnesol), which are necessary for the prenylation of viral proteins, is blocked and the formation of mature, virulent virus particles is broken. As a consequence, the maturation of viral particles is inhibited, and defective particles are formed. Polyprenol was extracted from greenery (pine, fir and spruce needles, mulberry leaves, etc.), purified by chromatography, phosphorylated and identified by HPLC and NMR. Obtained PPP was used as antiviral in some experimental models in vitro and in vivo. During numerous studies, it was found that PPP manifested versatile antiviral effects, both in vitro and in vivo. The maximum effect was observed with viruses in which the presence of prenylated proteins was established, namely influenza A virus, HIV-1, tick-borne encephalitis virus, hepatitis A and C viruses, herpes simplex viruses type 1 and 2, some coronavirus. The available data obtained both in the experimental conditions and during clinical trials allow us to regard PPPs as safe and effective medicine for prevention and treatment of viral diseases.

Effect of Statin Use on the Clinical Manifestations, Laboratory Test Results and Outcome of Lyme Neuroborreliosis

Statins have anti-inflammatory and potentially antimicrobial activity, but whether they have a beneficial effect on the course of infectious diseases is controversial. In this study, we assessed the impact of pre-existing statin use on the course and outcome of Lyme neuroborreliosis manifested as meningoradiculitis (Bannwarth’s syndrome). One hundred and twenty three consecutive patients with Bannwarth’s syndrome, of whom 18 (14.6%) were being treated with statins, were included in the study. To assess the influence of statin use on the course and outcome of the disease, univariate and multivariable analyses were performed. No statistically significant association was found between statin pre-treatment and the clinical manifestations, laboratory test results, and outcome of Bannwarth’s syndrome. In conclusion, pre-existing use of statins did not significantly impact either the clinical presentation or the outcome of Bannwarth’s syndrome.