Influenza-associated monophasic neuromyelitis optica

Infectious optic neuropathy (ION), how to recognise it and manage it

Optic neuropathy can be of infectious or non-infectious/idiopathic aetiology. Many infectious organisms can cause optic neuropathy that can be of varied presentation including papillitis, retrobulbar optic neuritis, neuroretinitis, and optic perineuritis. Detailed history, ocular, systemic/neurologic examination along with appropriate laboratory evaluation can help clinicians to identify the infectious agent causing optic neuropathy. In spite of recent advanced techniques in serological testing and molecular diagnostics like polymerase chain reaction (PCR), the identification of these pathogens is still a diagnostic challenge. It is ideal to have an infectious disease (ID) consultant in the management team, as most of these infections are multisystem involving diseases. Most infectious agents can be effectively treated with specific antibiotics, with or without corticosteroid therapy, but visual recovery is highly variable and depends entirely on early diagnosis of the causative agent. This review article will provide an overview of common pathogens involved in ION and will describe their management paradigms.

The description of neuromyelitis optica spectrum disorder: Patient registry in Yangtze River Delta area of China

OBJECTIVE

To describe the clinical features of neuromyelitis optica spectrum disorder (NMOSD) through patient registry in Yangtze River Delta area of China.

METHODS

A total of 502 consecutive patients diagnosed with aquaporin-4 antibody (AQP4-ab)-positive NMOSD were registered between December 2018 to January 2021 in multiple tertiary referral centers within the framework of Yangtze River Delta of China. Their baseline data were reviewed, and follow-up clinical information were collected prospectively.

RESULTS

The mean age at onset was 37.3 (range 3-80 years) years and the female-to-male ratio was 8.1:1. The median disease duration was 47 months (interquartile range [IQR] 25-84 months). A total of 1372 attacks of the 502 patients were recorded till the last follow-up, with a median annualized relapse rate of 0.4 (IQR 0.3-0.6). Nearly one-fourth (24.5%, 336/1372) of the attacks had prodromic events, including upper respiratory tract infection (36.3%, 122/336), fever (20.2%, 68/336) and pregnancy-related issues (17.9%, 60/336), etc. Myelitis was the most common attack type throughout the disease course (51.4%, 705/1372), followed by optic neuritis (ON, 43.1%, 592/1372). As for onset phenotype, ON (37.3%, 187/502) prevailed over myelitis (28.3%, 142/502). The median time to first relapse was 12 months (IQR 5-25 months). Patients with brainstem encephalitis at onset were more likely to have other anatomical region involved in subsequent attacks (p < 0.001), compared to other onset type. The median serum AQP4-ab titer measured by cell-based assays was 1:100 (IQR 1:32-1:320, range 1:10-1:10,000). The baseline AQP4-ab titer in cerebrospinal fluid (r = 0.542, p <0.001), overall ARR (r = 0.232, p< 0.001) and the EDSS scores at last follow-up (r = 0.119, p = 0.022) significantly correlated with baseline serum AQP4-ab titer. Antinuclear antibodies (48.4%), thyroid peroxidase antibodies (30.7%), and anti-SSA antibodies (26.2%) represented the most frequent concomitant antibodies, while autoimmune thyroid disorders (13.1%, 66/502) and Sjogren's syndrome (10.8%, 54/502) were the most common accompanying autoimmune diseases. Till the last follow-up, 403 patients received preventive treatments. Azathioprine represented the most common initial treatment, mycophenolate mofetil and rituximab was the most common second and third-line treatment, respectively. The EDSS score at the last follow-up ranged from 0 to 8.5 with a median of 2 (IQR 1-3).

CONCLUSIONS

A comprehensive clinical picture of patients with AQP4-ab-positive NMOSD in Yangtze River Delta area of China was presented. More information on disease tragedy and predictive prognostic factors could be generated through long-term observations.

Extensive Longitudinal Transverse Myelitis after Influenza A Virus Infection in a Patient with Systemic Lupus Erythematosus

Transverse myelitis (TM) is a rare complication seen in 1–2% of patients with systemic lupus erythematosus (SLE). Viral infections may cause TM in these patients by causing a dysregulation of their immune system. We report a 30-year-old woman with SLE who had influenza A and a few days later developed urinary retention, bilateral lower extremity paralysis, upper extremity weakness, and optic nerve and macular edema. Magnetic resonance imaging showed C4-T12 hyperintense lesions consistent with TM. She was treated with intravenous methylprednisolone 1 g daily for 3 days and then 6 cycles of monthly intravenous cyclophosphamide. This treatment was followed by oral prednisone. She had a remarkable clinical response. Visual acuity improved to her baseline, and muscle strength almost fully recovered. Clinicians should be aware that viral infections, including influenza, may induce TM. This case highlights the importance of early recognition and prompt treatment with immunosuppressive drugs in such cases.

Longitudinally extensive transverse myelitis with positive aquaporin-4 IgG associated with dengue infection: a case report and systematic review of cases

BACKGROUND

Neuromyelitis Optica Spectrum Disorder can be associated with parainfectious and post-infectious triggers. Dengue virus infection is one of the most common arbovirus infections in the world, and may present with neurological manifestations.

OBJECTIVES

We present a case of DENV-associated with LETM and positive aquaporin-4 IgG, and a systematic review of published cases.

METHODS

Medline (Ovid) and PubMed were search through June 2021, for case reports, series and observational studies that described patients with DENV-associated LETM and/or NMOSD.

RESULTS

An adolescent girl who had recently immigrated from a Dengue-endemic region presented with a LETM with high positive AQP4-IgG titer and seropositive DENV IgM/IgG antibodies. She responded well to steroids and subsequently started maintenance rituximab for her NMOSD diagnosis.

LITERATURE REVIEW

22 publications describing 27 patients met inclusion criteria. In addition to this case, three published cases met current criteria for NMOSD with serological evidence of acute DENV infection.

CONCLUSIONS

It is unknown whether there is a pathophysiological association between DENV infection and NMOSD. Regardless, if an immune-mediated event is suspected, particularly NMOSD, appropriate immunotherapy should be considered early. Decision regarding long term immunotherapy may depend on index of suspicion of true NMOSD, and this is where AQP4-IgG status and follow-up is helpful.

Epidemiology of Demyelinating Diseases in Korean Pediatric Patients

The epidemiology of demyelinating diseases in the Korean pediatric population has not been reported to date. This study aimed to identify the epidemiology of demyelinating diseases in Korean children by using big data. The subjects were children (0-17 years old) diagnosed with acute-disseminated encephalomyelitis, multiple sclerosis, neuromyelitis optica, and Guillain-Barré syndrome enrolled in the Korean Health Insurance Review and Assessment Service (HIRA) from January 2010 to December 2017.Of 1722 enrolled children, 553 (32.1%) had acute-disseminated encephalomyelitis, 170 (9.9%) had multiple sclerosis, 68 (3.9%) had neuromyelitis optica, and 931 (54.1%) had Guillain-Barré syndrome. The male-female ratios were 1.47:1 in acute-disseminated encephalomyelitis, 1.43:1 in Guillain-Barré syndrome, 1:1.66 in multiple sclerosis, and 1:1.62 in neuromyelitis optica. Demyelinating diseases were most prevalent in summer. The prevalence differed by region, with 545 (31.6%) in Seoul and 298 (17.3%) in Gyeonggi. This study is the first to identify the incidence of demyelinating diseases in South Korea.

Anti-aquaporin-4 Antibody Positive Optic Neuritis Following Scrub Typhus in an Elderly Female

INTRODUCTION

Aquaporin-4 antibody (AQP4-Ab) is specific for neuromyelitis optica spectrum disorder (NMOSD) and so is helpful to distinguish NMOSD from other autoimmune diseases. Several viral infections may play a role in the onset of NMOSD.

CASE REPORT

We describe a case of a previous healthy 82-year-old woman who presented with acute visual loss occurring 3 weeks after scrub typhus. Physical examination showed a relatively afferent pupillary defect in the right eye and ophthalmoscopy revealed edema of the right optic disc. Enhanced magnetic resonance imaging revealed enhancement of the right optic nerve. Serological testing showed AQP4-Ab. After methylprednisolone pulse therapy followed by oral tapering of prednisolone, visual dysfunction was improved. Subsequently she experienced no attacks for 5 years.

CONCLUSIONS

Optic neuritis (ON) associated with scrub typhus is extremely rare. Our case support that scrub typhus could trigger ON in a lifelong asymptomatic patient with AQP4-Ab and AQP4-Ab should be considered in a very old age patient with suspected postinfectious inflammatory ON.

Neuroinfluenza: evaluation of seasonal influenza associated severe neurological complications in children (a multicenter study)

PURPOSE

Although influenza primarily affects the respiratory system, in some cases, it can cause severe neurological complications. Younger children are especially at risk. Pediatric literature is limited on the diagnosis, treatment, and prognosis of influenza-related neurological complications. The aim of the study was to evaluate children who suffered severe neurological manifestation as a result of seasonal influenza infection.

METHODS

The medical records of 14 patients from six hospitals in different regions of the country were evaluated. All of the children had a severe neurological manifestations related to laboratory-confirmed influenza infection.

RESULTS

Median age of the patients was 59 months (6 months-15.5 years) and nine (64.3%) were male. Only 4 (28.6%) of the 14 patients had a comorbid disease. Two patients were admitted to hospital with influenza-related late complications, and the remainder had acute complication. The most frequent complaints at admission were fever, altered mental status, vomiting, and seizure, respectively. Cerebrospinal fluid (CSF) analysis was performed in 11 cases, and pleocytosis was found in only two cases. Neuroradiological imaging was performed in 13 patients. The most frequent affected regions of nervous system were as follows: cerebellum, brainstem, thalamus, basal ganglions, periventricular white matter, and spinal cords. Nine (64.3%) patients suffered epileptic seizures. Two patients had focal seizure, and the rest had generalized seizures. Two patients developed status epilepticus. Most frequent diagnoses of patients were encephalopathy (n = 4), encephalitis (n = 3), and meningitis (n = 3), respectively. The rate of recovery without sequelae from was found to be 50%. At discharge, three (21.4%) patients had mild symptoms, another three (21.4%) had severe neurological sequelae. One (7.1%) patient died. The clinical findings were more severe and outcome was worse in patients <5 years old than patients >5 years old and in patients with comorbid disease than previously healthy group.

CONCLUSION

Seasonal influenza infection may cause severe neurological complications, especially in children. Healthy children are also at risk such as patients with comorbid conditions. All children who are admitted with neurological findings, especially during the influenza season, should be evaluated for influenza-related neurological complications even if their respiratory complaints are mild or nonexistent.

Infectious optic neuropathies: a clinical update

Different forms of optic neuropathy causing visual impairment of varying severity have been reported in association with a wide variety of infectious agents. Proper clinical diagnosis of any of these infectious conditions is based on epidemiological data, history, systemic symptoms and signs, and the pattern of ocular findings. Diagnosis is confirmed by serologic testing and polymerase chain reaction in selected cases. Treatment of infectious optic neuropathies involves the use of specific anti-infectious drugs and corticosteroids to suppress the associated inflammatory reaction. The visual prognosis is generally good, but persistent severe vision loss with optic atrophy can occur. This review presents optic neuropathies caused by specific viral, bacterial, parasitic, and fungal diseases.

Influenza-associated MOG antibody-positive longitudinally extensive transverse myelitis: a case report

Background

Myelin-oligodendrocyte glycoprotein antibody (MOG antibodies) was found in various demyelinated diseases. This is the first report of a patient with longitudinally extensive transverse myelitis with an extremely high titer of MOG antibodies after an influenza infection. This case supports the view that MOG antibodies are linked to longitudinally extensive transverse myelitis and that influenza infection might trigger the MOG antibodies.

Case presentation

A 32-year-old healthy male developed high fever, dysesthesia and paraesthesia below the C2 area, muscle weakness of the bilateral lower extremities, and urinary retention ten days after an influenza type A infection. Magnetic resonance imaging revealed a longitudinal lesion in the spinal cord extending from C2 to the spinal conus. There were no lesions in the brain or optic nerves. Established cell-based immunoassays revealed that he was positive for MOG antibodies (titer = 65,536) and negative for anti-aquaporin 4 antibodies (AQP4 antibodies). He fully recovered after steroid pulse therapy followed by 60 mg prednisolone.

Conclusion

This is the first report of influenza A-associated longitudinally extensive transverse myelitis with a high titer anti-MOG antibodies. Our case report supports a relationship between anti-MOG antibodies and longitudinally extensive transverse myelitis, which was triggered by influenza infection. Further studies are needed to establish the clinical significance of anti-MOG antibodies for diagnosis, treatment, and prognosis.

Identification of common biological pathways and drug targets across multiple respiratory viruses based on human host gene expression analysis

BACKGROUND

Pandemic and seasonal respiratory viruses are a major global health concern. Given the genetic diversity of respiratory viruses and the emergence of drug resistant strains, the targeted disruption of human host-virus interactions is a potential therapeutic strategy for treating multi-viral infections. The availability of large-scale genomic datasets focused on host-pathogen interactions can be used to discover novel drug targets as well as potential opportunities for drug repositioning.

METHODS/RESULTS

In this study, we performed a large-scale analysis of microarray datasets involving host response to infections by influenza A virus, respiratory syncytial virus, rhinovirus, SARS-coronavirus, metapneumonia virus, coxsackievirus and cytomegalovirus. Common genes and pathways were found through a rigorous, iterative analysis pipeline where relevant host mRNA expression datasets were identified, analyzed for quality and gene differential expression, then mapped to pathways for enrichment analysis. Possible repurposed drugs targets were found through database and literature searches. A total of 67 common biological pathways were identified among the seven different respiratory viruses analyzed, representing fifteen laboratories, nine different cell types, and seven different array platforms. A large overlap in the general immune response was observed among the top twenty of these 67 pathways, adding validation to our analysis strategy. Of the top five pathways, we found 53 differentially expressed genes affected by at least five of the seven viruses. We suggest five new therapeutic indications for existing small molecules or biological agents targeting proteins encoded by the genes F3, IL1B, TNF, CASP1 and MMP9. Pathway enrichment analysis also identified a potential novel host response, the Parkin-Ubiquitin Proteasomal System (Parkin-UPS) pathway, which is known to be involved in the progression of neurodegenerative Parkinson's disease.

CONCLUSIONS

Our study suggests that multiple and diverse respiratory viruses invoke several common host response pathways. Further analysis of these pathways suggests potential opportunities for therapeutic intervention.