Elevated cerebrospinal fluid nitrite level in human immunodeficiency virus-infected patients with neurosyphilis

Cerebrospinal fluid metabolomics: detection of neuroinflammation in human central nervous system disease

The high morbidity and mortality of neuroinflammatory diseases drives significant interest in understanding the underlying mechanisms involved in the innate and adaptive immune response of the central nervous system (CNS). Diagnostic biomarkers are important to define treatable neuroinflammation. Metabolomics is a rapidly evolving research area offering novel insights into metabolic pathways, and elucidation of reliable metabolites as biomarkers for diseases. This review focuses on the emerging literature regarding the detection of neuroinflammation using cerebrospinal fluid (CSF) metabolomics in human cohort studies. Studies of classic neuroinflammatory disorders such as encephalitis, CNS infection and multiple sclerosis confirm the utility of CSF metabolomics. Additionally, studies in neurodegeneration and neuropsychiatry support the emerging potential of CSF metabolomics to detect neuroinflammation in common CNS diseases such as Alzheimer's disease and depression. We demonstrate metabolites in the tryptophan-kynurenine pathway, nitric oxide pathway, neopterin and major lipid species show moderately consistent ability to differentiate patients with neuroinflammation from controls. Integration of CSF metabolomics into clinical practice is warranted to improve recognition and treatment of neuroinflammation.

Usefulness of the FilmArray meningitis/encephalitis (M/E) panel for the diagnosis of infectious meningitis and encephalitis in Taiwan

BACKGROUND/PURPOSE

Early recognition of causative pathogens is critical for the appropriate management of central nervous system infection and improved outcomes. The BioFire^® FilmArray^® Meningitis/Encephalitis Panel (BioFire^® ME Panel, BioFire Diagnostics) is the first U.S. Food and Drug Administration (FDA)-approved multiplex PCR assay that allows the rapid detection of 14 pathogens, including bacteria (n = 6), viruses (n = 7), and fungi (n = 1), from cerebrospinal fluid (CSF). The performance of the panel is expected to be dependent on the epidemiology of M/E in different geographical regions.

METHODS

In this preliminary study, we used the BioFire^® ME Panel in 42 subjects who presented to the emergency department with symptoms of M/E in our hospital. The results were compared to conventional culture, antigen detection, PCR, and various laboratory findings.

RESULTS

The panel detected six positive samples, of which five were viral and one bacterial. We observed an overall agreement rate of 88% between the BioFire^® ME Panel results and the conventional methods. There were no false-positive findings, but five discordant results were observed for enterovirus, herpes simplex virus type 1, Escherichia coli, and Cryptococcus species.

CONCLUSIONS

The BioFire^® ME Panel performed equivalently to the traditional PCR methods for virus detection, and better than bacterial cultures. This revolutionary system represents a paradigm shift in the diagnosis of M/E and may aid in the rapid identification of community-acquired M/E. However, the usefulness of this tool is limited in regions with a high prevalence of infectious M/E caused by microorganisms not included in the panel.

[Neurosyphilis: an Age-old Problem that is Still Relevant Today]

Neurosyphilis is the clinical manifestation of syphilis that can arise during either the early or late stages of infection. Even though dedicated treatment for all clinical forms of syphilis has been available for many years, the advanced stages of the disease are still prevalent, with irreversible sequelae. This article reviews the current evidence, diagnostic methods and specific treatment for tertiary syphilis.

Correlation of inducible nitric oxide synthase (iNOS) inhibition with TNF-α, caspase-1, FasL and TLR-3 in pathogenesis of rabies in mouse model

The role of inflammatory cytokines such as interleukin-1α/β (IL-1α/β), IL-6, IL-10, tumour necrosis factor-alpha (TNF-α), interferons, nitric oxide (NO) and inducible nitric oxide synthase (iNOS) in pathogenesis of rabies is being actively pursued. Presently, levels of certain immune molecules in pathogenesis of rabies in mice have been investigated. CVS strain of rabies infection resulted in early increase in iNOS, TNF-α, caspase-1, Fas ligand (FasL) and toll-like receptor-3 (TLR-3) mRNA levels in brain, and nitric oxide levels in serum. The severity of clinical signs and microscopic lesions largely correlated with NO levels. Aminoguanidine (AG; iNOS inhibitor) decreased NO production with delay in development of clinical signs and increase in survival time. Prolonged survival time correlated with reduced viral load evident by real-time PCR, reduced fluorescent signals of rabies antigen in brain and reduced immunohistochemistry signals in neuronal cytoplasm. These parameters suggested that nitric oxide did influence the rabies virus replication. Inhibition of iNOS by AG administration led to decreased expression of TNF-α, caspase-1, FasL and TLR-3 mRNA levels suggesting that increase in NO levels in rabies virus infection possibly contributed to development of disease through inflammation, apoptosis and immune-evasive mechanisms.