The role of infection and vaccination in the genesis of optic neuritis and multiple sclerosis in children

Vaccination of multiple sclerosis patients during the COVID-19 era: Novel insights into vaccine safety and immunogenicity

Multiple sclerosis (MS) is an incurable autoimmune disease known to cause widespread demyelinating lesions in the central nervous system (CNS) and a host of debilitating symptoms in patients. The development of MS is believed to be driven by the breakdown of the blood brain barrier, subsequent infiltration by CD4⁺ and CD8⁺ T cells, and widespread CNS inflammation and demyelination. Disease modifying therapies (DMTs) profoundly disrupt these processes and therefore compose an essential component of disease management. However, the effects of these therapeutic agents on vaccine safety and immunogenicity in individuals with MS are not yet fully understood. As such, the primary objective of this review article was to summarize the findings of recently conducted studies on vaccine safety and immunogenicity in MS patients treated with DMTs, particularly in the context of the ongoing coronavirus disease 2019 (COVID-19) pandemic. Discussed in this review are vaccinations against influenza, yellow fever, human papillomavirus, measles, mumps, rubella, Streptococcus pneumoniae, hepatitis B, and COVID-19. This article additionally reviews our current understanding of COVID-19 severity and incidence in this patient population, the risks and benefits of vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and vaccination guidelines set forth by MS societies and organizations.

Acute Thyroiditis and Bilateral Optic Neuritis following SARS-CoV-2 Vaccination with CoronaVac: A Case Report

Purpose: To describe a case of acute thyroiditis and bilateral optic neuritis associated with SARS-CoV-2 vaccination. Methods: A single case report from a tertiary referral center. Results: The patient described in the following case report developed acute thyroiditis and bilateral optic neuritis following SARS-CoV-2 vaccination. The patient underwent pulse therapy followed by oral tapering corticosteroid therapy with an improvement of the bilateral disc swelling and the visual field, and recovery of thyroid-stimulating hormone to the normal limits. Conclusions: Although the association between immunization and the onset of demyelinating manifestations of the central nervous system is well documented, this is the first reported case of bilateral optic neuritis and acute thyroiditis and subsequent to administration of vaccination against SARS-CoV-2.

Current Immunological and Clinical Perspective on Vaccinations in Multiple Sclerosis Patients: Are They Safe after All?

Vaccines work by stimulating the immune system, and their immunogenicity is key in achieving protection against specific pathogens. Questions have been raised whether in Multiple Sclerosis (MS) patients they could induce disease exacerbation and whether vaccines could possibly act as a trigger in the onset of MS in susceptible populations. So far, no correlation has been found between the vaccinations against influenza, hepatitis B, tetanus, human papillomavirus, measles, mumps, rubella, varicella zoster, tuberculosis, yellow fever, or typhoid fever and the risk of MS. Further research is needed for the potential protective implications of the tetanus and Bacillus Calmette-Guerin vaccines in MS patients. Nowadays with the emerging coronavirus disease 2019 (COVID-19) and recent vaccinations approval and arrival, the risk-benefit in MS patients with regards to safety and efficacy of COVID-19 vaccination in those treated with immunosuppressive therapies is of paramount importance. In this manuscript, we demonstrate how different vaccine types could be related to the immunopathogenesis of MS and discuss the risks and benefits of different vaccinations in MS patients.

Unilateral Optic Neuritis: A Rare Complication after Measles-Mumps-Rubella Vaccination in a 30-Year-Old Woman

Purpose. To report a case of unilateral optic neuritis following Measles-Mumps-Rubella (MMR) vaccination. Methods. A 30-year-old female developed unilateral optic neuritis five days after a Measles-Mumps-Rubella (MMR) booster vaccination. The patient displayed unilateral involvement, with severe visual loss. However, visual acuity improved significantly after four days of intravenous steroid therapy with 500 mg/day of methylprednisolone. Conclusions. Optic neuritis is one of the rare complications associated with the mumps, measles, and rubella vaccine. It may be a toxic reaction to the nonviral component of the vaccine, but the exact etiology is unknown. Postvaccination neuritis is generally bilateral and usually affects children. In adults, unilateral optic neuritis is usually correlated with multiple sclerosis (MS).

Optic neuritis associated with influenza B virus meningoencephalitis

Various postinfectious neurological manifestations have been described associated to influenza viruses. Optic neuritis is a serious, often reversible disease reported among several infectious diseases and vaccines complications. We report a case of optic neuritis following an influenza B virus infection in a 10-year-old male.

Pathogenesis of pediatric multiple sclerosis

Onset of multiple sclerosis in childhood occurs in 3-5% of patients. There is limited, but growing knowledge about the underlying pathobiology of pediatric MS. It is crucial to better understand this area in order to address central questions in the field: 1) Can pediatric multiple sclerosis inform us about factors related to disease initiation and propagation? 2) What are the biomarkers of disease course in pediatric multiple sclerosis; 3) Does pediatric multiple sclerosis pathogenesis differ from adult-onset multiple sclerosis; 4) How can we optimize treatment in pediatric demyelinating diseases? 5) Can pediatric multiple sclerosis provide insights into the environmental risk factors for multiple sclerosis in general? Here we review the current knowledge of the pathogenesis of multiple sclerosis in children, and address the five questions raised above.

The clinical characteristics of optic neuritis in Korean children

Purpose

To study the clinical characteristics of optic neuritis in Korean children.

Methods

A retrospective review of the medical charts of 20 patients who were diagnosed with optic neuritis before age 10 was conducted in this study. Data were collected on the demographics, clinical features, use of intravenous corticosteroids, neuroimaging, and diagnosis of multiple sclerosis.

Results

The mean age at diagnosis was 6.5 ± 1.8 years (range, 3 to 9 years). Seventeen patients (85%) were female, and 13 patients (65%) exhibited bilateral diseases. Visual acuity had decreased to ≤20 / 200 in 16 of the 20 patients, and recovered to ≥20 / 40 in 16 of the 20 patients. The mean duration between the worst visual acuity and 20 / 40 was 2.30 ± 2.91 months. Intravenous corticosteroid treatment was performed in 15 patients and exerted a beneficial effect on the visual outcomes. Disc swelling was observed in 75.8% of the affected eyes. Multiple sclerosis was diagnosed in five patients with a mean follow-up period of 21.9 ± 20.3 months. The presence of lesions in brain magnetic resonance images was identified as the most significant factor with regards to the occurrence of multiple sclerosis.

Conclusions

In children with optic neuritis, a profound decrease in initial visual acuity and rapid recovery of visual acuity were confirmed. Corticosteroid treatment resulted in a beneficial effect on visual outcomes, but had no effect on the risk of multiple sclerosis.

Younger children with MS have a distinct CSF inflammatory profile at disease onset

BACKGROUND

The clinical and MRI presentation differs between earlier- and later-onset pediatric multiple sclerosis (MS), whereas the effect of age on the CSF inflammatory profile is unknown and may contribute to delayed diagnosis.

OBJECTIVES

To compare the CSF cellular and immunoglobulin G (IgG) profiles between earlier- and later-onset pediatric MS.

METHODS

We queried the databases of 6 pediatric MS centers for earlier-onset (onset <11 years) and later-onset (> or = 11 and <18 years) patients with MS or clinically isolated syndrome who underwent CSF analysis within the first 3 months of presentation (observational study). We compared CSF white blood cell (WBC) differential count, IgG index, and IgG oligoclonal bands between age groups.

RESULTS

We identified 40 earlier-onset (mean age at onset = 7.2 +/- 2.7 years, 60% females) and 67 later-onset pediatric MS patients (15.1 +/- 1.7 years, 63% females). Although WBC count tended to be higher in earlier-onset patients (median = 9/mm(3) [0-343] vs 6 [0-140], p = 0.15), they had a lower proportion of lymphocytes (70% [0-100] vs 93% [0-100] of WBCs, p = 0.0085; difference = +3% per 1-year increase of age, p = 0.0011) and higher proportion of neutrophils than later-onset patients (0.5% [0-75] vs 0% [0-50] of WBCs, p = 0.16; difference = -1% per 1-year increase of age, p = 0.033). In earlier-onset disease, fewer patients had an elevated IgG index than in the later-onset group (35% vs 68% of patients, p = 0.031).

CONCLUSION

Age modifies the CSF profile at pediatric multiple sclerosis (MS) onset, which may mislead the diagnosis. Our findings suggest an activation of the innate rather than the adaptive immune system in the earlier stages of MS or an immature immune response.

Isolated bilateral optic neuritis in acute disseminated encephalomyelitis

PURPOSE

We present a 4-year-old girl with isolated visual loss related to a bilateral oedematous optic neuropathy of unknown origin, occurring after an episode of viral illness.

METHODS

A cerebral MRI was performed, showing bilateral enhancement of the optic nerves and bilateral, diffuse, cerebral white matter lesions.

RESULTS

The MRI scan suggested acute disseminated encephalomyelitis. Treatment with intravenous steroids and immunoglobulins resulted in favourable visual recovery.

CONCLUSIONS

Bilateral isolated optic neuritis in childhood may be the only presenting symptom in acute disseminated encephalomyelitis, which requires appropriate evaluation and therapeutic management.

Environmental risk factors in multiple sclerosis aetiology

The epidemiology of multiple sclerosis (MS) has been intensively studied. It is conceptualised as a complex disease in which genetic and environmental factors act together to cause disease. There are temporal and geographic variations in disease risk, and risk of disease may be affected by migration between regions of differing risk. Numerous potential causal factors including infection, immunisations, physical and emotional stressors, climate, diet, and occupational exposures have been studied using various observational study designs. Thus far, no single environmental exposure has been consistently identified as a causal factor in MS, but sufficient data have accumulated that causal pathways should be postulated and tested. This review will focus on the environmental epidemiology of MS.

The first rapid onset optic neuritis after measles–rubella vaccination: case report

During the largest mass campaign for measles-rubella (MR) vaccination 33,000,000 people with an age range of 5-25 years were vaccinated in Iran. Some complications were encountered, including a rare case of optic neuritis. In the past 30 years of medical literature, five cases of optic neuritis have been reported but all of them were developed at least 8 days after vaccination. We are supposed to report the first case of rapid onset optic neuritis in which the complication came out just in few hours in a 16 years old boy.

Optic neuritis in children--clinical and electrophysiological follow-up

Optic neuritis (ON) in children usually presents with visual loss, relative afferent pupillary defect (RAPD), abnormal optic disc appearance, defects of visual field and colour vision, as well as with abnormalities of visual evoked potentials (VEP). Both, clinical and VEP parameters, improve after the attack; the time until recovery, however, is as yet unknown. The aim of this study was to follow-up children with ON for 1 year and to determine clinical and VEP recovery. Twelve children (six with bilateral, six with unilateral ON) were studied in the acute phase and systematically followed-up for 1 year. The results show that initially, visual acuity was diminished in all eyes, while after 1 year, in only 14% of them. Optic disc appearance was abnormal in 83.3% of the eyes in the acute phase, and in 85% after 1 year. At the disease onset RAPD could be detected in 67%, visual field defects in 58.5%, and colour vision defects in 50% of eyes, but none of these abnormalities persisted in any eye until the end of study. VEP were abnormal in 83% of eyes in the acute phase and in 56% at the final follow-up (at 6 or 12 months). VEP normalization, when occurred, was mostly observed during the first 6 months. Complete clinical and VEP recovery was observed in three children. Both, clinical and electrophysiological recovery in children with ON were relatively substantial and fast within the first year. VEP improvement may indicate better prognosis.

Multiple sclerosis in children

Multiple sclerosis (MS) is traditionally the domain of adult neurologists due to its characteristic presentation during early adult life. Although descriptions of infants with MS appeared in the beginning of the last century and the first autopsy was described even earlier, it was not until 1980 that childhood onset MS was recognized and subsequently well characterized. In spite of this, the awareness of pediatricians and pediatric neurologists to the occurrence of MS especially in infants and young children is still unsatisfactory. It is not infrequent that a meticulous, time consuming and costly search for metabolic and degenerative disorders other that MS is initiated before the diagnosis of MS is considered. This leads to a significant diagnostic and therapeutic delay in many young patients. Moreover, when the presentation is acute and characterized by confusion, seizures, CSF pleocytosis following a viral infection, a diagnosis of meningoencephalitis will be frequently reached. In this review, updated data on frequency, epidemiology, some special clinical and radiological features of childhood onset MS, outcome and treatment will be briefly discussed with the purpose of alerting physicians to the possibility of the occurrence of MS even in infants and young children.

Optic neuritis in multiple sclerosis

PURPOSE

To review the clinical features, natural history, potential pathogenic mechanisms, differential diagnosis, and management of optic neuritis in multiple sclerosis.

METHODS

Relevant literature regarding optic neuritis in multiple sclerosis from 1970 to the present was reviewed.

RESULTS

Optic neuritis is an acute inflammatory optic neuropathy. It is the most common type of optic neuropathy causing acute visual loss in young adults (peak age at 30-40 years), especially among women. Patients usually present with an acute reduction of visual acuity, orbital pain exacerbated by eye movements, dyschromatopsia, and an afferent papillary defect, with or without swelling of the optic nerve head. Visual field testing most often reveals central defects, but others, such as centrocecal, can also occur. Magnetic resonance image (MRI) scanning of the brain should be undertaken in all cases of acute optic neuritis for diagnostic and prognostic purposes. The brain lesions of multiple sclerosis are commonly seen as T2 ovoid high-signal white matter lesions on MRI scans of the brain located in perivenular regions perpendicular to ventricles with variable enhancement. For atypical presentations of optic neuritis, additional laboratory tests, such as cerebrospinal fluid analysis, serologic tests, and visual evoked potentials, prove to be useful in the diagnosis and subsequent management of the patient. The recommended treatment for optic neuritis is intravenous steroids, as shown in the Optic Neuritis Treatment Trial (ONTT).

CONCLUSION

Optic neuritis is often the initial presentation of multiple sclerosis. Recent advances in the understanding of the immune basis for multiple sclerosis has led to earlier and more effective treatment of this disease.

Vaccinations and the risk of relapse in multiple sclerosis. Vaccines in Multiple Sclerosis Study Group

BACKGROUND

There has been some concern that vaccination may precipitate the onset of multiple sclerosis or lead to relapses. Since the recent hepatitis B vaccination program in France, there have been new reports of an increased risk of active multiple sclerosis after vaccination.

METHODS

We conducted a case-crossover study to assess whether vaccinations increase the risk of relapse in multiple sclerosis. The subjects were patients included in the European Database for Multiple Sclerosis who had a relapse between 1993 and 1997. The index relapse was the first relapse confirmed by a visit to a neurologist and preceded by a relapse-free period of at least 12 months. Information on vaccinations was obtained in a standardized telephone interview and confirmed by means of medical records. Exposure to vaccination in the two-month risk period immediately preceding the relapse was compared with that in the four previous two-month control periods for the calculation of relative risks, which were estimated with the use of conditional logistic regression.

RESULTS

Of 643 patients with relapses of multiple sclerosis, 15 percent reported having been vaccinated during the preceding 12 months. The reports of 94 percent of these vaccinations were confirmed. Of all the patients, 2.3 percent had been vaccinated during the preceding two-month risk period as compared with 2.8 to 4.0 percent who were vaccinated during one or more of the four control periods. The relative risk of relapse associated with exposure to any vaccination during the previous two months was 0.71 (95 percent confidence interval, 0.40 to 1.26). There was no increase in the specific risk of relapse associated with tetanus, hepatitis B, or influenza vaccination (range of relative risks, 0.22 to 1.08). Analyses based on risk periods of one and three months yielded similar results.

CONCLUSIONS

Vaccination does not appear to increase the short-term risk of relapse in multiple sclerosis.

Multiple sclerosis, acute disseminated encephalomyelitis, and related conditions

Multiple sclerosis (MS) and acute disseminated encephalomyelitis (ADEM) are conditions whose closely related pathology suggests shared pathophysiological elements, but whose clinical courses are usually, but not always quite dissimilar. The former is largely a disease of adulthood, the latter of childhood. Optic neuritis, demyelinative transverse myelitis, and Devic's syndrome are neurological syndromes that may occur as manifestations of either MS or ADEM. Patients with Miller-Fisher syndrome and encephalomyelradiculoneuropathy usually have features suggesting ADEM in combination with acute demyelinative polyneuropathy. These various conditions and other forms of ADEM share an indistinct border with encephalitides, granulomatous, and vasculitic conditions. MS, ADEM, and the pertinent syndromic subtypes, their differential diagnosis, treatment, and prognosis are considered in this review. Acute cerebellar ataxia is a syndrome that is likely to be pathophysiologically distinct from ADEM, although its occurrence as a postinfectious illness suggests a distant kinship. It is also reviewed.

Vaccination and autoimmunity-'vaccinosis': a dangerous liaison?

The question of a connection between vaccination and autoimmune illness (or phenomena) is surrounded by controversy. A heated debate is going on regarding the causality between vaccines, such as measles and anti-hepatitis B virus (HBV), and multiple sclerosis (MS). Brain antibodies as well as clinical symptoms have been found in patients vaccinated against those diseases. Other autoimmune illnesses have been associated with vaccinations. Tetanus toxoid, influenza vaccines, polio vaccine, and others, have been related to phenomena ranging from autoantibodies production to full-blown illness (such as rheumatoid arthritis (RA)). Conflicting data exists regarding also the connection between autism and vaccination with measles vaccine. So far only one controlled study of an experimental animal model has been published, in which the possible causal relation between vaccines and autoimmune findings has been examined: in healthy puppies immunized with a variety of commonly given vaccines, a variety of autoantibodies have been documented but no frank autoimmune illness was recorded. The findings could also represent a polyclonal activation (adjuvant reaction). The mechanism (or mechanisms) of autoimmune reactions following immunization has not yet been elucidated. One of the possibilities is molecular mimicry; when a structural similarity exists between some viral antigen (or other component of the vaccine) and a self-antigen. This similarity may be the trigger to the autoimmune reaction. Other possible mechanisms are discussed. Even though the data regarding the relation between vaccination and autoimmune disease is conflicting, it seems that some autoimmune phenomena are clearly related to immunization (e.g. Guillain-Barre syndrome). The issue of the risk of vaccination remains a philosophical one, since to date the advantages of this policy have not been refuted, while the risk for autoimmune disease has not been irrevocably proved. We discuss the pros and cons of this issue (although the temporal relationship (i.e. always 2-3 months following immunization) is impressive).

Acute multifocal retinitis

PURPOSE

To describe the clinical presentation, ophthalmoscopic and fluorescein angiographic findings, and natural history of 14 eyes in nine otherwise healthy, young-to-middle-age adults with idiopathic, acute, multifocal retinitis.

METHODS

A retrospective review of the clinical and photographic records of nine patients.

RESULTS

Five of the nine patients reported a flu-like illness 1 to 2 weeks before the onset of visual symptoms. Ophthalmoscopic findings included mild vitritis (11 of 14), mild optic nerve edema (seven of 14), macular star (two of 14) or localized neurosensory retinal detachment (two of 14) caused by adjacent focus of retinitis, and small branch-artery occlusion (two of 14). Fluorescein angiography showed early blocking hypofluorescence with late staining hyperfluorescence of all areas of retinitis. In patients with optic nerve edema, the disk showed late leakage. Specific tests for collagen vascular disorders, as well as systemic syphilis and toxoplasmosis titers, were negative in all patients. Five of six patients with histories of cat exposure tested negative for systemic Bartonella henselae antibodies. One patient with a history of cat exposure refused testing. Clinical courses were self-limited, with complete return of vision without treatment in all but one eye, which developed a juxtafoveal scar and localized traction retinal detachment in an area of prior retinitis.

CONCLUSIONS

Idiopathic acute multifocal retinitis should be considered in any otherwise healthy, young-to-middle-age adult with acute loss of vision in the presence of multifocal retinitis, particularly when accompanied by an antecedent flu-like illness. Patients with idiopathic acute multifocal retinitis usually have favorable clinical course.

Optic neuritis following measles/rubella vaccination in two 13-year-old children

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Environmental risk factors in MS: a case-control study in Moscow

Environmental influences operating as possible risk factors in MS were studied in Moscow. The study included 155 MS patients from the Neurology Departments and the outpatient clinics of the First City Hospital of Moscow and 155 controls matched for sex, age in 5-year intervals, nationality, and origin (Moscow vs. non Moscow). 72.3% of controls were recruited among patients from the same hospital as the cases. The remaining controls were volunteers from the hospital staff or medical students. Exposures before age 15 were of special interest. MS patients reported a higher frequency of: 1) tonsillitis; 2) allergic reactions age 15; 3) head trauma below age 16; 4) a predominant meat vs. vegetable diet during childhood. Stratified analysis and logistic regression pointed to "meat predominance" as the most significant risk factor. Other associations were confounded by the respondents' occupations/education.

A controlled study of potential risk factors preceding exacerbation in multiple sclerosis

A wide variety of potential risk factors for acute exacerbations in multiple sclerosis were evaluated in a one year case-control study. Eighty nine consecutive patients with clinically definite multiple sclerosis and relapsing remitting course presenting with a relapse between January and December 1992 were compared with patients matched for age, sex, and degree of disability, who did not experience clinical exacerbations during the same period. Only potential risk factors occurring in the three months preceding the interview were considered patients. Relapsing patients reported no significant increase in the frequency of any risk factor in the three month period before exacerbation compared with the control group. These results suggest that most relapses are not preceded by the conditions commonly considered as risk factors.

Clinical and MRI assessment of disease activity in patients with multiple sclerosis after influenza vaccination

We investigated the possible effects of influenza vaccination on disease activity in multiple sclerosis (MS). Six patients were evaluated clinically during the year preceding and the year following influenza vaccination. Gadolinium-enhanced magnetic resonance imaging (Gd-MRI) was performed one day before and at days 15 and 45 after vaccination. Cumulatively, we did not observe increases in clinical or MRI disease activity following vaccination, with the exception of one case. This was the patient with the highest clinical disease activity during the year preceding vaccination. These results support and supplement previous observations, indicating that influenza vaccination is a safe procedure in multiple sclerosis. Nevertheless, it should be used with caution in patients with active/progressing disease.

Multiple sclerosis. Observations and reflections--a personal memoir

The pathogenesis of MS has become better understood as a result of recent advances in several areas, particularly in epidemiology and neuro-imaging. A number of epidemiologically based conclusions need to be revised, most importantly the putative direct relationship between prevalence and latitude, and the concept that epidemics of MS have occurred in some parts of the world. It is now clear that genetic factors play a much more important role in the genesis of the disease than environmental factors, although the latter cannot be ignored. The existence of a genetic susceptibility, coupled with either protective or enhancing factors, which may be genetic or environmental, is recognized as being most important in individuals of northern European origin. Much evidence suggests that the disease is initiated by a viral illness (or possibly a vaccination) at some time before puberty. This first antigenic challenge results in the development of what is called the "MS trait", a systemic condition that may never develop into the actual disease and may be observed as well in the unaffected siblings of MS patients. The trait is almost certainly a manifestation of an alteration of the immune system; its most important effect is to render the blood-brain barrier more vulnerable to a variety of agents that will increase its permeability. In order for MS to involve the central nervous system, loss of integrity of the blood-brain barrier is an obligatory step, an observation which has now been amply confirmed by neuroimaging studies. This effect upon the blood-brain barrier appears to be non-specific, since it may result from such diverse causes as a viral infection, a vaccination, or mild trauma. Edema and inflammation follow, but myelinoclasia is not always a consequence; thus plaque formation may not occur and the initial lesion of MS may disappear without leaving a trace. The actual mechanism of myelinoclasia, and the role played in it by lymphocytes, remain unknown. Although the disease does affect the central nervous system, it may remain asymptomatic for a long time after the actual plaque is formed, even for the person's entire life.