Autoimmunity in Guillain-Barré syndrome associated with Zika virus infection and beyond

Zika and Dengue Virus Autoimmunity: An Overview of Related Disorders and Their Potential Mechanisms

Zika virus (ZIKV) and dengue virus (DENV) are two major mosquito-borne flaviviruses that pose a significant threat to the global public health system, particularly in tropical regions. The clinical outcomes related to these viral pathogens can vary from self-limiting asymptomatic infections to various forms of life-threatening pathological conditions such as haemorrhagic disorders. In addition to the direct effects of the viral pathogens, immune processes play also a significant function in the development of diseases mediated by ZIKV and DENV. Studing these processes is important for developing safer vaccines and targeted therapeutic strategies. These viruses have been reported to trigger various autoimmune disorders affecting different parts of human organ systems. It also has been shown that preexisting immunity to ZIKV or DENV can impact the outcome of subsequent infections caused by another virus. ZIKV and DENV infection can promote the development of autoimmune disorders by different mechanisms, such as molecular mimicry and autoantibody formation. The present review provides an overview of various autoimmune disorders associated with ZIKV and DENV infection and their potential underlying mechanisms.

Protective and stochastic correlation between infectious diseases and autoimmune disorders

A priori, early exposure to a wide range of bacteria, viruses, and parasites appears to fortify and regulate the immune system, potentially reducing the risk of autoimmune diseases. However, improving hygiene conditions in numerous societies has led to a reduction in these microbial exposures, which, according to certain theories, could contribute to an increase in autoimmune diseases. Indeed, molecular mimicry is a key factor triggering immune system reactions; while it seeks pathogens, it can bind to self-molecules, leading to autoimmune diseases associated with microbial infections. On the other hand, a hygiene-based approach aimed at reducing the load of infectious agents through better personal hygiene can be beneficial for such pathologies. This review sheds light on how the evolution of the innate immune system, following the evolution of molecular patterns associated with microbes, contributes to our protection but may also trigger autoimmune diseases linked to microbes. Furthermore, it addresses how hygiene conditions shield us against autoimmune diseases related to microbes but may lead to autoimmune pathologies not associated with microbes.

Sustained Microglial Activation Promotes Synaptic Loss and Neuronal Dysfunction after Recovery from ZIKV Infection

Zika virus (ZIKV), transmitted by Aedes mosquitoes, has been a global health concern since 2007. It primarily causes fetal microcephaly and neuronal defects through maternal transmission and induces neurological complications in adults. Recent studies report elevated proinflammatory cytokines and persistent neurological alterations post recovery, but the in vivo mechanisms remain unclear. In our study, viral RNA loads in the brains of mice infected with ZIKV peaked at 7 days post infection and returned to baseline by day 21, indicating recovery. RNA sequencing of the cerebral cortex at 7 and 21 days revealed upregulated genes related to neuroinflammation and microglial activation. Histological analyses indicated neuronal cell death and altered neurite morphology owing to severe neuroinflammation. Additionally, sustained microglial activation was associated with increased phospho-Tau levels, constituting a marker of neurodegeneration. These findings highlight how persistent microglial activation leads to neuronal dysfunction post ZIKV recovery, providing insights into the molecular pathogenesis of ZIKV-induced brain abnormalities.

SARM1 Depletion Slows Axon Degeneration in a CNS Model of Neurotropic Viral Infection

Zika virus (ZIKV) is a neurotropic flavivirus recently linked to congenital ZIKV syndrome in children and encephalitis and Guillain-Barré syndrome in adults. Neurotropic viruses often use axons to traffic to neuronal or glial cell somas where they either remain latent or replicate and proceed to infect new cells. Consequently, it has been suggested that axon degeneration could represent an evolutionarily conserved mechanism to limit viral spread. Whilst it is not known if ZIKV transits in axons, we previously reported that ZIKV infection of glial cells in a murine spinal cord-derived cell culture model of the CNS is associated with a profound loss of neuronal cell processes. This, despite that postmitotic neurons are relatively refractory to infection and death. Here, we tested the hypothesis that ZIKV-associated degeneration of neuronal processes is dependent on activation of Sterile alpha and armadillo motif-containing protein 1 (SARM1), an NADase that acts as a central executioner in a conserved axon degeneration pathway. To test this, we infected wild type and Sarm1 homozygous or heterozygous null cell cultures with ZIKV and examined NAD⁺ levels as well as the survival of neurons and their processes. Unexpectedly, ZIKV infection led to a rapid SARM1-independent reduction in NAD⁺. Nonetheless, the subsequent profound loss of neuronal cell processes was SARM1-dependent and was preceded by early changes in the appearance of β-tubulin III staining. Together, these data identify a role for SARM1 in the pathogenesis of ZIKV infection, which may reflect SARM1's conserved prodegenerative function, independent of its NADase activity.

Case of rare association of peripheral neuropathy with mixed connective tissue disorder

Chronic inflammatory demyelinating polyneuropathy (CIDP) is probably the best-recognised progressive immune-mediated peripheral neuropathy. It presents with symmetrical, motor predominant peripheral neuropathy that produces both distal and proximal weakness. Here we report a case of a 38-year-old man who presented with chronic additive large and small joint inflammatory polyarthritis, associated with morning stiffness, anasarca associated with frothy urine and progressive episodic, relapsing and remitting, sensorimotor lower motor neuron type quadriparesis without any bladder and bowel involvement. He was diagnosed as a case of CIDP, and the aetiology was found out to be mixed connective tissue disorder, which is a rare association with CIDP. The patient responded dramatically to glucocorticoid.

Intramuscular Delivery of Replicon RNA Encoding ZIKV-117 Human Monoclonal Antibody Protects against Zika Virus Infection

Monoclonal antibody (mAb) therapeutics are an effective modality for the treatment of infectious, autoimmune, and cancer-related diseases. However, the discovery, development, and manufacturing processes are complex, resource-consuming activities that preclude the rapid deployment of mAbs in outbreaks of emerging infectious diseases. Given recent advances in nucleic acid delivery technology, it is now possible to deliver exogenous mRNA encoding mAbs for in situ expression following intravenous (i.v.) infusion of lipid nanoparticle-encapsulated mRNA. However, the requirement for i.v. administration limits the application to settings where infusion is an option, increasing the cost of treatment. As an alternative strategy, and to enable intramuscular (IM) administration of mRNA-encoded mAbs, we describe a nanostructured lipid carrier for delivery of an alphavirus replicon encoding a previously described highly neutralizing human mAb, ZIKV-117. Using a lethal Zika virus challenge model in mice, our studies show robust protection following alphavirus-driven expression of ZIKV-117 mRNA when given by IM administration as pre-exposure prophylaxis or post-exposure therapy.

Zika autoimmunity and Guillain-Barré syndrome

PURPOSE OF REVIEW

To summarize the recent data regarding Guillain-Barré syndrome (GBS) as an autoimmune disorder following infection with Zika virus (ZIKV) infection, including the proposed pathogenic mechanisms and the role of autoantibodies.

RECENT FINDINGS

The loss of self-tolerance that leads to autoimmune diseases is a multifactorial process that may be illustrated as 'the mosaic of autoimmunity'. Infectious agents may contribute to the development of autoimmunity by several proposed mechanisms. One of the central mechanisms is molecular mimicry, which is also the most plausible mechanism in the case of ZIKV-induced autoimmune disorders.A recent meta-analysis found a low prevalence of GBS associated with ZIKV infection. Nevertheless, the estimated cost of illness for patients with GBS associated with ZIKV are tremendous and exceed 4.7 million dollars per year in Brazil alone.

SUMMARY

Currently, there is sufficient data to indicate that ZIKV infection is one of many triggers and factors that may contribute to the development GBS. Thus, it is advised to evaluate and determine ZIKV exposure and infection in the management of potential GBS patients.

Zika Virus infection and Guillain-Barré syndrome in Northeastern Mexico: A case-control study

BACKGROUND

Beginning August 2017, we conducted a prospective case-control investigation in Monterrey, Mexico to assess the association between Zika virus (ZIKV) and Guillain-Barré syndrome (GBS).

METHODS

For each of 50 GBS case-patients, we enrolled 2-3 afebrile controls (141 controls in total) matched by sex, age group, and presentation to same hospital within 7 days.

RESULTS

PCR results for ZIKV in blood and/or urine were available on all subjects; serum ZIKV IgM antibody for 52% of case-patients and 80% of controls. Subjects were asked about antecedent illness in the two months prior to neurological onset (for case-patients) or interview (for controls). Laboratory evidence of ZIKV infection alone (PCR+ or IgM+) was not significantly different between case-patients and controls (OR: 1.26, 95% CI: 0.45-3.54) but antecedent symptomatic ZIKV infection [a typical ZIKV symptom (rash, joint pain, or conjunctivitis) plus laboratory evidence of ZIKV infection] was higher among case-patients (OR: 12.45, 95% CI: 1.45-106.64). GBS case-patients with laboratory evidence of ZIKV infection were significantly more likely to have had typical ZIKV symptoms than controls with laboratory evidence of ZIKV infection (OR: 17.5, 95% CI: 3.2-96.6). This association remained significant even when only GBS case-patients who were afebrile for 5 days before onset were included in the analysis, (OR 9.57 (95% CI: 1.07 to 85.35).

CONCLUSIONS

During ZIKV epidemics, this study indicates that increases in GBS will occur primarily among those with antecedent symptomatic ZIKV.

Classification of Guillain–Barré Syndrome Subtypes Using Sampling Techniques with Binary Approach

Guillain–Barré Syndrome (GBS) is an unusual disorder where the body’s immune system affects the peripheral nervous system. GBS has four main subtypes, whose treatments vary among them. Severe cases of GBS can be fatal. This work aimed to investigate whether balancing an original GBS dataset improves the predictive models created in a previous study. purpleBalancing a dataset is to pursue symmetry in the number of instances of each of the classes.The dataset includes 129 records of Mexican patients diagnosed with some subtype of GBS. We created 10 binary datasets from the original dataset. Then, we balanced these datasets using four different methods to undersample the majority class and one method to oversample the minority class. Finally, we used three classifiers with different approaches to creating predictive models. The results show that balancing the original dataset improves the previous predictive models. The goal of the predictive models is to identify the GBS subtypes applying Machine Learning algorithms. It is expected that specialists may use the model to have a complementary diagnostic using a reduced set of relevant features. Early identification of the subtype will allow starting with the appropriate treatment for patient recovery. This is a contribution to exploring the performance of balancing techniques with real data.

Tryptophan Trimers and Tetramers Inhibit Dengue and Zika Virus Replication by Interfering with Viral Attachment Processes

Here, we report a class of tryptophan trimers and tetramers that inhibit (at low micromolar range) dengue and Zika virus infection in vitro These compounds (AL family) have three or four peripheral tryptophan moieties directly linked to a central scaffold through their amino groups; thus, their carboxylic acid groups are free and exposed to the periphery. Structure-activity relationship (SAR) studies demonstrated that the presence of extra phenyl rings with substituents other than COOH at the N1 or C2 position of the indole side chain is a requisite for the antiviral activity against both viruses. The molecules showed potent antiviral activity, with low cytotoxicity, when evaluated on different cell lines. Moreover, they were active against laboratory and clinical strains of all four serotypes of dengue virus as well as a selected group of Zika virus strains. Additional mechanistic studies performed with the two most potent compounds (AL439 and AL440) demonstrated an interaction with the viral envelope glycoprotein (domain III) of dengue 2 virus, preventing virus attachment to the host cell membrane. Since no antiviral agent is approved at the moment against these two flaviviruses, further pharmacokinetic studies with these molecules are needed for their development as future therapeutic/prophylactic drugs.

Seroprevalences of autoantibodies and anti-infectious antibodies among Ghana's healthy population

Autoantibodies, which are antibodies that target self-epitopes, have considerable diagnostic, prognostic and predictive value in specific autoimmune diseases. Various infectious agents have been linked via numerous mechanisms to the formation of different autoantibodies. Therefore, estimating the prevalence of autoantibodies and anti-infectious antibodies in different populations is of high importance. Different genetic and environmental pressures, such as these found in Ghana's different geographical provinces, may affect the prevalence of autoantibodies. In this study, we assessed the seroprevalence of a diverse panel of autoantibodies and anti-infectious antibodies among the healthy Ghanaian population and investigated possible environmental and genetic predispositions for autoantibodies and autoimmunity. The sera of 406 healthy individuals were obtained from Greater Accra, Upper West, Eastern and Volta regions. Multiplexed assay and chemiluminescent immunoassay techniques were utilized to assess the presence of a panel of autoantibodies and anti-infectious antibodies. We found a high prevalence of anti-HSV-1 IgG (91-100%), anti-EBNA IgG (81-93%) and anti-EBV-VCA IgG (97-100%) antibodies. The prevalence of ANA (at least one of: anti-dsDNA; anti-chromatin; anti-ribosomal-P; anti-Ro/SSA; anti-La/SSB; anti-centromere B; anti-Sm; anti-Sm/RNP; anti-Scl-70; anti-Jo1; anti-DFS70) was estimated at 14%. An inverse association between anti-HSV-2 antibodies and ANA (p = 0.044; adjusted OR = 0.398; CI [0.162-0.975]) was found, after adjusting for differences in gender, age, and familial history of autoimmune diseases. A trend towards reduced seroprevalence of anti-dsDNA antibodies among subjects who were positive for anti-HSV-2 antibodies was also noted (p = 0.1). In conclusion, the inverse association between anti-HSV-2 antibodies and ANA positivity suggests a possible protective role of HSV-2 infection against autoimmunity.

Augmented Zika and Dengue Neutralizing Antibodies Are Associated With Guillain-Barré Syndrome

The role of neutralizing antibodies in Zika-induced Guillain-Barré syndrome (GBS) has not yet been investigated. We conducted a case-control study using sera from the 2016 Zika epidemic in Colombia to determine the neutralizing antibody activity against Zika virus (ZIKV) and dengue virus serotype 2 (DENV2). We observed increased neutralizing antibody titers against DENV2 in ZIKV-infected individuals compared with uninfected controls and higher titers to both ZIKV and DENV2 in ZIKV-infected patients diagnosed with GBS compared with non-GBS ZIKV-infected controls. These data suggest that high neutralizing antibody titers to DENV and to ZIKV are associated with GBS during ZIKV infection.

Anti-ganglioside antibodies in patients with Zika virus infection-associated Guillain-Barré Syndrome in Brazil

Zika virus infection is associated with the development of Guillain-Barré syndrome (GBS), a neurological autoimmune disorder caused by immune recognition of gangliosides and other components at nerve membranes. Using a high-throughput ELISA, we have analyzed the anti-glycolipid antibody profile, including gangliosides, of plasma samples from patients with Zika infections associated or not with GBS in Salvador, Brazil. We have observed that Zika patients that develop GBS present higher levels of anti-ganglioside antibodies when compared to Zika patients without GBS. We also observed that a broad repertoire of gangliosides was targeted by both IgM and IgG anti-self antibodies in these patients. Since Zika virus infects neurons, which contain membrane gangliosides, antigen presentation of these infected cells may trigger the observed autoimmune anti-ganglioside antibodies suggesting direct infection-induced autoantibodies as a cause leading to GBS development. Collectively, our results establish a link between anti-ganglioside antibodies and Zika-associated GBS in patients.

Optimization of 1,3-disubstituted urea-based inhibitors of Zika virus infection

Zika virus (ZIKV) has become a public health concern worldwide due to its association with congenital abnormalities and neurological diseases. To date, no effective vaccines or antiviral drugs have been approved for the treatment of ZIKV infection, and new inexpensive therapeutic options are urgently needed. In this study, we have used an in vitro plaque assay to assess an antiviral activity of the second generation of anti-ZIKV compounds, based on 1,3-disubstituted (thio)urea scaffold. Several compounds in the library were found to possess excellent activity against Zika virus with IC₅₀ values <200 pM. The most active analog, A5 exhibited an exceptional IC₅₀ = 85.1 ± 1.7 pM. Further analysis delineated structural requirements necessary for potent antiviral effects of this class of compounds. Collectively, our findings suggest that 1,3-disubstituted (thio)urea derivatives are excellent preclinical candidates for the development of anti-ZIKV therapeutics.

Viruses and Autoimmunity: A Review on the Potential Interaction and Molecular Mechanisms

For a long time, viruses have been shown to modify the clinical picture of several autoimmune diseases, including type 1 diabetes (T1D), systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), Sjögren’s syndrome (SS), herpetic stromal keratitis (HSK), celiac disease (CD), and multiple sclerosis (MS). Best examples of viral infections that have been proposed to modulate the induction and development of autoimmune diseases are the infections with enteric viruses such as Coxsackie B virus (CVB) and rotavirus, as well as influenza A viruses (IAV), and herpesviruses. Other viruses that have been studied in this context include, measles, mumps, and rubella. Epidemiological studies in humans and experimental studies in animal have shown that viral infections can induce or protect from autoimmunopathologies depending on several factors including genetic background, host-elicited immune responses, type of virus strain, viral load, and the onset time of infection. Still, data delineating the clear mechanistic interaction between the virus and the immune system to induce autoreactivity are scarce. Available data indicate that viral-induced autoimmunity can be activated through multiple mechanisms including molecular mimicry, epitope spreading, bystander activation, and immortalization of infected B cells. Contrarily, the protective effects can be achieved via regulatory immune responses which lead to the suppression of autoimmune phenomena. Therefore, a better understanding of the immune-related molecular processes in virus-induced autoimmunity is warranted. Here we provide an overview of the current understanding of viral-induced autoimmunity and the mechanisms that are associated with this phenomenon.

Transcriptional Profile of Aedes aegypti Leucine-Rich Repeat Proteins in Response to Zika and Chikungunya Viruses

Aedes aegypti (L.) is the primary vector of chikungunya, dengue, yellow fever, and Zika viruses. The leucine-rich repeats (LRR)-containing domain is evolutionarily conserved in many proteins associated with innate immunity in invertebrates and vertebrates, as well as plants. We focused on the AaeLRIM1 and AaeAPL1 gene expressions in response to Zika virus (ZIKV) and chikungunya virus (CHIKV) infection using a time course study, as well as the developmental expressions in the eggs, larvae, pupae, and adults. RNA-seq analysis data provided 60 leucine-rich repeat related transcriptions in Ae. aegypti in response to Zika virus (Accession number: GSE118858, accessed on: August 22, 2018, GEO DataSets). RNA-seq analysis data showed that AaeLRIM1 (AAEL012086-RA) and AaeAPL1 (AAEL009520-RA) were significantly upregulated 2.5 and 3-fold during infection by ZIKV 7-days post infection (dpi) of an Ae. aegypti Key West strain compared to an Orlando strain. The qPCR data showed that LRR-containing proteins related genes, AaeLRIM1 and AaeAPL1, and five paralogues were expressed 100-fold lower than other nuclear genes, such as defensin, during all developmental stages examined. Together, these data provide insights into the transcription profiles of LRR proteins of Ae. aegypti during its development and in response to infection with emergent arboviruses.

The Effect of Permethrin Resistance on Aedes aegypti Transcriptome Following Ingestion of Zika Virus Infected Blood

Aedes aegypti (L.) is the primary vector of many emerging arboviruses. Insecticide resistance among mosquito populations is a consequence of the application of insecticides for mosquito control. We used RNA-sequencing to compare transcriptomes between permethrin resistant and susceptible strains of Florida Ae. aegypti in response to Zika virus infection. A total of 2459 transcripts were expressed at significantly different levels between resistant and susceptible Ae. aegypti. Gene ontology analysis placed these genes into seven categories of biological processes. The 863 transcripts were expressed at significantly different levels between the two mosquito strains (up/down regulated) more than 2-fold. Quantitative real-time PCR analysis was used to validate the Zika-infection response. Our results suggested a highly overexpressed P450, with AAEL014617 and AAEL006798 as potential candidates for the molecular mechanism of permethrin resistance in Ae. aegypti. Our findings indicated that most detoxification enzymes and immune system enzymes altered their gene expression between the two strains of Ae. aegypti in response to Zika virus infection. Understanding the interactions of arboviruses with resistant mosquito vectors at the molecular level allows for the possible development of new approaches in mitigating arbovirus transmission. This information sheds light on Zika-induced changes in insecticide resistant Ae. aegypti with implications for mosquito control strategies.

A Nanostructured Lipid Carrier for Delivery of a Replicating Viral RNA Provides Single, Low-Dose Protection against Zika

Since the first demonstration of in vivo gene expression from an injected RNA molecule almost two decades ago,¹ the field of RNA-based therapeutics is now taking significant strides, with many cancer and infectious disease targets entering clinical trials.² Critical to this success has been advances in the knowledge and application of delivery formulations. Currently, various lipid nanoparticle (LNP) platforms are at the forefront,³ but the encapsulation approach underpinning LNP formulations offsets the synthetic and rapid-response nature of RNA vaccines.⁴ Second, limited stability of LNP formulated RNA precludes stockpiling for pandemic readiness.⁵ Here, we show the development of a two-vialed approach wherein the delivery formulation, a highly stable nanostructured lipid carrier (NLC), can be manufactured and stockpiled separate from the target RNA, which is admixed prior to administration. Furthermore, specific physicochemical modifications to the NLC modulate immune responses, either enhancing or diminishing neutralizing antibody responses. We have combined this approach with a replicating viral RNA (rvRNA) encoding Zika virus (ZIKV) antigens and demonstrated a single dose as low as 10 ng can completely protect mice against a lethal ZIKV challenge, representing what might be the most potent approach to date of any Zika vaccine.

Divergent Roles of Antiself Antibodies during Infection

Antiself antibodies are most commonly associated with autoimmune disorders, but a large body of evidence indicates that they are also present in numerous infectious diseases. These autoimmune antibodies appear transiently during infection with a number of viruses, bacteria, and parasites and in some cases have been associated with the development of autoimmune disorders that develop after infection has been cleared. Traditionally these infection-associated autoantibodies are considered an erroneous byproduct of a legitimate immune response, but their possible role in the clearance of microbes and infected cells or inhibition of host-cell invasion suggests that they may be present because of their beneficial protective role against various infections.

Autoimmune Neurological Conditions Associated With Zika Virus Infection

Zika virus (ZIKV) is an emerging flavivirus rapidly spreading throughout the tropical Americas. Aedes mosquitoes is the principal way of transmission of the virus to humans. ZIKV can be spread by transplacental, perinatal, and body fluids. ZIKV infection is often asymptomatic and those with symptoms present minor illness after 3 to 12 days of incubation, characterized by a mild and self-limiting disease with low-grade fever, conjunctivitis, widespread pruritic maculopapular rash, arthralgia and myalgia. ZIKV has been linked to a number of central and peripheral nervous system injuries such as Guillain-Barré syndrome (GBS), transverse myelitis (TM), meningoencephalitis, ophthalmological manifestations, and other neurological complications. Nevertheless, mechanisms of host-pathogen neuro-immune interactions remain incompletely elucidated. This review provides a critical discussion about the possible mechanisms underlying the development of autoimmune neurological conditions associated with Zika virus infection.

Zika virus in Thailand

This review examines the historic reports of the presence of Zika virus (ZIKV) in Thailand, as well as collates such information as exists on the current situation in Thailand with regards to ZIKV. We suggest that considerable caution must be applied in interpreting early serological studies, but that ZIKV is presently circulating over much of Thailand, with increasing numbers of cases being reported.

FAS promoter polymorphisms and serum sFas level are associated with increased risk of nerve damage in Bangladeshi patients with Guillain-Barré syndrome

Guillain-Barré syndrome (GBS) is an autoimmune disorder of the peripheral nervous system triggered by molecular mimicry between pathogen lipopolysaccharides and host nerve gangliosides. Polymorphisms in the Fas receptor (FAS) and Fas ligand (FASL) genes may potentially alter the elimination of autoreactive immune cells and affect disease susceptibility or disease severity in GBS. We detected single nucleotide polymorphisms (SNPs) in FAS (-1377G/A and -670A/G) and FASL (-843C/T) in a prospective cohort of 300 patients with GBS and 300 healthy controls from the Bangladeshi population. Genotype distributions were not significantly different between patients with GBS and healthy controls. The FAS -670 AG heterozygous (P = 0.0005, OR = 2.5, 95% CI = 1.5–4.2) and GG homozygous (P = 0.0048, OR = 2.6, 95% CI = 1.3–5.0) genotypes were more common in patients with anti-GM1 antibodies than patients without anti-GM1 antibodies. The FAS -670 G allele was more prevalent in anti-GM1 antibody-positive than -negative patients (P = 0.0002, OR = 1.9, 95% CI = 1.4–2.7) and also in patients with the axonal subtype than demyelinating subtype (P < 0.0001, OR = 4.8, 95% CI = 2.3–10.1). The 1377G/-670G GG haplotype was significantly associated with the axonal subtype (P < 0.0001) and anti-ganglioside antibody-positivity (P = 0.0008) in GBS. Serum sFas (237.5 pg/mL vs. 159.5 pg/mL; P < 0.0001) and sFasL (225.1 pg/mL vs. 183.4 pg/mL; P = 0.0069) were elevated in patients with GBS compared to healthy controls, and among patients with high serum sFas was associated with severe GBS (P = 0.0406). In conclusion, this study indicates FAS-FASL promoter SNPs may promote the production of cross-reactive anti-ganglioside antibodies in GBS.

Variable Sensitivity in Molecular Detection of Zika Virus in European Expert Laboratories: External Quality Assessment, November 2016

Zika virus (ZIKV) infections are a significant public health concern. A strong capability for ZIKV detection is an absolute requirement for adequate preparedness and response strategies and individual patient care. The objective of this study was to assess and improve the capability of European expert laboratories for molecular testing for ZIKV through an external quality assessment (EQA) scheme. Laboratories were provided a panel of 12 samples which included negative samples, samples containing African- or Asian-lineage ZIKV at various concentrations (10³ to 10⁹ copies/ml), and samples containing dengue virus, yellow fever virus, or chikungunya virus. The results were analyzed on the basis of the outcomes of testing for the samples and the extraction and detection method used. Samples with a ZIKV RNA status scored correctly by >50% of the laboratories were designated the core sample. A total of 85 panel outcomes were submitted by 50 laboratories in 31 countries. The results designated all samples as core samples. Thirty-three percent (28/85) of the panel outcomes identified all samples. Analysis at the laboratory level showed that only 40% of the laboratories (20/50), representing 45% of the countries, scored sufficiently; i.e., they had at least one test operational that scored all core samples correctly. There is a need for improvement of the molecular detection of ZIKV in 60% of the participating laboratories. While the specificity of the tests was more robust, the results of the EQA showed large variation in test sensitivity. Improvements should focus on both nucleic acid extraction and ZIKV detection methods.

Neurological Presentation of Zika Virus Infection Beyond the Perinatal Period

PURPOSE OF REVIEW

Our purpose was to summarize the current knowledge about the neurological presentation of Zika virus infection after the perinatal period. Other Flaviviruses infections, such as West Nile virus (WNV) or Japanese encephalitis virus (JEV), can result in neuro-invasive disease such as myelitis, encephalitis, or meningitis. We aimed at describing the specificities of ZV neurological infection.

RECENT FINDINGS

The recent outbreaks demonstrated clearly the neurotropism of ZV. However, by contrast with other Flaviviruses, the most frequent neurological presentation of ZV infection beyond the perinatal period was Guillain-Barré syndrome, especially the demyelination form of GBS. Encephalitis and myelitis seem to occur less frequently after ZV infection than after WNV or JEV infection. The pathophysiology of neurological ZV infections is still poorly understood and no specific treatment is available. Moreover, no data is available about long-term persisting symptoms and possible impairment of patients after the acute clinical episode.