Interleukin-6 and oligoclonal IgG synthesis in children with acute disseminated encephalomyelitis

The pathogenesis of multiple sclerosis: a series of unfortunate events

Multiple sclerosis (MS) is characterized by the chronic inflammatory destruction of myelinated axons in the central nervous system. Several ideas have been put forward to clarify the roles of the peripheral immune system and neurodegenerative events in such destruction. Yet, none of the resulting models appears to be consistent with all the experimental evidence. They also do not answer the question of why MS is exclusively seen in humans, how Epstein-Barr virus contributes to its development but does not immediately trigger it, and why optic neuritis is such a frequent early manifestation in MS. Here we describe a scenario for the development of MS that unifies existing experimental evidence as well as answers the above questions. We propose that all manifestations of MS are caused by a series of unfortunate events that usually unfold over a longer period of time after a primary EBV infection and involve periodic weakening of the blood-brain barrier, antibody-mediated CNS disturbances, accumulation of the oligodendrocyte stress protein αB-crystallin and self-sustaining inflammatory damage.

Cytokines and chemokines profile in encephalitis patients: A meta-analysis

BACKGROUND

Encephalitis is caused by autoimmune or infectious agents marked by brain inflammation. Investigations have reported altered concentrations of the cytokines in encephalitis. This study was conducted to determine the relationship between encephalitis and alterations of cytokine levels in cerebrospinal fluid (CSF) and serum.

METHODS

We found possibly suitable studies by searching PubMed, Embase, Scopus, and Web of Science, systematically from inception to August 2021. 23 articles were included in the meta-analysis. To investigate sources of heterogeneity, subgroup analysis and sensitivity analysis were conducted. The protocol of the study has been registered in PROSPERO with a registration ID of CRD42021289298.

RESULTS

A total of 23 met our eligibility criteria to be included in the meta-analysis. A total of 12 cytokines were included in the meta-analysis of CSF concentration. Moreover, 5 cytokines were also included in the serum/plasma concentration meta-analysis. According to the analyses, patients with encephalitis had higher CSF amounts of IL-6, IL-8, IL-10, CXCL10, and TNF-α than healthy controls. The alteration in the concentration of IL-2, IL-4, IL-17, CCL2, CXCL9, CXCL13, and IFN-γ was not significant. In addition, the serum/plasma levels of the TNF-α were increased in encephalitis patients, but serum/plasma concentration of the IL-6, IL-10, CXCL10, and CXCL13 remained unchanged.

CONCLUSIONS

This meta-analysis provides evidence for higher CSF concentrations of IL-6, IL-8, IL-10, CXCL10, and TNF-α in encephalitis patients compared to controls. The diagnostic and prognostic value of these cytokines and chemokines should be investigated in future studies.

Inflammatory Markers Combined With Metalloproteinase-9, Neopterin, and S100B Concentrations May Indicate the Pathogenesis of Central Nervous System Diseases in Children

The identification of central nervous system inflammation etiology leads to adjusted therapy. We analyzed the potential inflammatory and neuro-axonal damage markers in children. Our target was to correlate the findings with a disease's course or a sequalae risk and assess their clinical usefulness. The study included 96 children with symptoms of central nervous system inflammation who underwent diagnostics. The research group involved 24 children with autoimmune disorders and 31 with neuroinfection. The control group included patients with both etiologies excluded. We analyzed the results of routine laboratory tests together with chosen serum (neopterin, interleukin [IL]-1β, IL-6) and CSF (metalloproteinase [MMP]-9, S100B protein) markers. In the whole cohort, CSF MMP-9 correlated with CSF cytosis and serum IL-6 and CRP. In the undivided neuroinflammatory group, CSF S100B correlated with serum IL-6 and IgM concentrations. CSF cytosis was associated with CSF MMP-9 and serum neopterin levels. Among the infective patients, IL-6 was linked with increased CSF MMP-9. We conclude that astroglial protein S100B, neopterin, and cytokine concentrations may enable predicting long-term consequences, whereas CSF MMP-9 concentration may reflect the actual central nervous system injury regardless of etiology.

[Herpesviruses and biomarkers in disseminated encephalomyelitis and multiple sclerosis in children (part II)]

Recently, the problem of demyelinating diseases in children is still very acute. This occurs, on the one hand, by high access and specificity of diagnostic methods and, on the other hand - by high morbidity of children different neuroinfectious diseases which can lead to demyelinating diseases. This literature review presents the currently available information on the autoantibodies and neurospecific protein role in the development of multiple sclerosis and acute disseminative encephalitis in children. The authors also describe their experience of complex etiopatogenic therapy and cytoflavin use that helps to reduce frequency and expression of demyelinating process and endothelium dysfunction in case of active herpesvirus infection.

[Herpesviruses and biomarkers in disseminated encephalomyelitis and multiple sclerosis in children]

The relevance of the study of demyelinating diseases is due to their increasing frequency in children, clarification of the role of infectious agents in their genesis, as well as the possibility of transformation of disseminated encephalomyelitis into multiple sclerosis. The literature review presents the currently available information on the causes of the development of demyelinating diseases, biomarkers of disseminated encephalomyelitis and multiple sclerosis, the causes of an unfavorable course and possible laboratory parameters indicating the transition from one disease to another, which can be used as prognostic factors. The authors also noted the experience of the authors on the importance of adequate etiopathogenetic therapy in changing the nature of the course of the disease, in particular, when confirming the relationship between the frequency of exacerbations of ADEM and MS with the activation of herpesvirus infections, courses of specific antiviral therapy are effective, as well as pathogenetic therapy aimed at correcting endothelial dysfunction using the drug cytoflavin.

Relationship Between Pregnancy and Acute Disseminated Encephalomyelitis: A Single-Case Study

The relationship between pregnancy and autoimmune diseases is unclear. This study investigated the possible role of local immune changes and the activation state of the HMGB1/TLR4/Nf-κB/IL-6 pathway at the maternal–fetal interface during pregnancy in the pathogenesis of acute disseminated encephalomyelitis (ADEM). Clinical data and blood samples of a patient with ADEM were collected to observe the dynamic changes in lymphocyte populations after an abortion. The expression of HMGB1, TLR4, Nf-κB, AQP4, IL-2, IL-4, IL-6, and TNF-α in the fetal membrane and placenta was compared between the patient with pregnancy-related ADEM and a woman with a normal pregnancy using Real-time qPCR and western blotting (WB). The patient was diagnosed with ADEM in the early stage of pregnancy after showing limb weakness symptoms. In the third month of gestation, the symptoms worsened, with a disturbance of consciousness and breathing. After the abortion, the patient relapsed with vertigo and visual rotation. Analysis of lymphocyte subsets by flow cytometry showed that B lymphocytes increased, while natural killer T lymphocytes decreased. WB and Real-time qPCR showed that the expression levels of HMGB1, TLR4, Nf-κB, AQP4, and IL-6 in the fetal membrane and placenta were higher in the patient with pregnancy-related ADEM than in the woman with a normal pregnancy, while those of IL-2 were lower in the patient than in the woman with a normal pregnancy. The local immune changes and the activation of the HMGB1/TLR4/Nf-κB/IL-6 pathway at the maternal–fetal interface may be related to the pathogenesis of ADEM.

Acute Disseminated Encephalomyelitis: Current Perspectives

Acute disseminated encephalomyelitis (ADEM) is an immune-mediated central nervous system (CNS) disorder, characterized by polyfocal symptoms, encephalopathy and typical magnetic resonance imaging (MRI) findings, that especially affects young children. Advances in understanding CNS neuroimmune disorders as well as the association of myelin oligodendrocyte glycoprotein antibody (MOG-Ab) with both monophasic and recurrent forms of ADEM have led to new insights into its definition, management and outcome. In this review, we aim to provide an update based on current epidemiologic, clinical, radiological and immunopathological aspects and clinical outcome of ADEM.

E.U. paediatric MOG consortium consensus: Part 3 - Biomarkers of paediatric myelin oligodendrocyte glycoprotein antibody-associated disorders

A first episode of acquired demyelinating disorder (ADS) in children is a diagnostic challenge as different diseases can express similar clinical features. Recently, antibodies against myelin oligodendrocyte glycoprotein (MOG) have emerged as a new ADS biomarker, which clearly allow the identification of monophasic and relapsing ADS forms different from MS predominantly in children. Due to the novelty of this antibody there are still challenges and controversies about its pathogenicity and best technique to detect it. In this manuscript we will discuss the recommendations and caveats on MOG antibody assays, role in the pathogenesis, and additionally discuss the usefulness of other potential new biomarkers in MOG-antibody associated disorders (MOGAD).

Acute Hemorrhagic Leukoencephalopathy: Pathological Features and Cerebrospinal Fluid Cytokine Profiles

BACKGROUND

Acute hemorrhagic leukoencephalopathy is a rare encephalopathy of unknown etiology, causing fulminant, hemorrhagic central nervous system demyelination with high mortality. It is unclear whether acute hemorrhagic leukoencephalopathy is an entirely distinct entity from acute disseminated encephalomyelitis.

PATIENTS AND METHODS

We report two patients with rapidly progressive neurological illness resulting in raised intracranial pressure and coma, with biopsy-proven acute hemorrhagic leukoencephalopathy (perivascular hemorrhages and demyelination, predominantly neutrophil infiltrates).

RESULTS

Acute cerebrospinal fluid showed pronounced T cell-associated cytokine elevation (interleukins 6, 8, and 17A) and CCL2 or CCL3, higher than in patients with acute disseminated encephalomyelitis, but no B cell-associated cytokine elevation.

CONCLUSION

Improved understanding of the immune process may provide rationale for use of anticytokine biologic agents.

[Cryptococcal meningoencephalitis in an immunocompetent patient caused by late onset exacerbation]

The case was a 29-year-old male with no previous history of serious disease. He developed headache and fever, which then worsened and he was admitted to our hospital. His temperature was 38.3°C and he had a stiff neck. In cerebrospinal fluid (CSF) tests, the opening pressure was high, the cell count was increased, and the CSF/serum glucose ratio was decreased. In addition, he was positive for cryptococcal antigen. According to these findings, he was diagnosed with cryptococcal meningoencephalitis and antifungal treatment was initiated. His symptoms then improved, but on day 18 after admission, he developed convulsions, and on day 28, right visual field defects appeared. Brain MRI showed disseminated lesions in the bilateral cerebral cortex. Despite a decrease of the cryptococcal antigenic value in the CSF, the IgG index was elevated. IL-6, 8 and 10 in CSF were high levels on Day 1, then gradually reduced as the symptoms improved. But on Day 28, worsening of symptoms, IL-10 was significantly increased dispite IL-6 and 8 reducing. Therefore, the exacerbation of his symptoms and expansion of the lesions were not caused by the Cryptococcus itself, and it was considered that they were due to the late deterioration of cryptococcosis, which responded to steroid treatment.

Chemokines CXCL10, CXCL11, and CXCL13 in acute disseminated encephalomyelitis, non-polio enterovirus aseptic meningitis, and neuroborreliosis: CXCL10 as initial discriminator in diagnostic algorithm?

We investigated potential diagnostic usefulness of serum and cerebrospinal fluid (CSF) concentrations of chemokines CXCL10, CXCL11, and CXCL13 in pediatric patients with acute disseminated encephalomyelitis (ADEM) (n = 23), non-polio enterovirus aseptic meningitis (NPEV AM) (n = 20), and neuroborreliosis (NB) (n = 21) and children with acute infectious diseases with neurological symptoms but with excluded neuroinfection/neuroinflammation (controls, n = 20). CSF levels of CXCL10 and CXCL11 were higher in patients with NPEV AM than those in other children, and CXCL10 levels showed a high discriminative potential (area under the receiver operating characteristic curve, ROC, 0.982) with high specificity and sensitivity (both 95%). CSF levels of CXCL13 were higher in NB patients than those in other children; however, discriminative potential (area under ROC curve 0.814) and diagnostic properties were moderate (sensitivity 67%, specificity 97%). Data suggest usefulness of chemokine quantification as a diagnostic aid in children with suspected ADEM, NPEV AM, or NB.

Expanding Role of T Cells in Human Autoimmune Diseases of the Central Nervous System

It is being increasingly recognized that a dysregulation of the immune system plays a vital role in neurological disorders and shapes the treatment of the disease. Aberrant T cell responses, in particular, are key in driving autoimmunity and have been traditionally associated with multiple sclerosis. Yet, it is evident that there are other neurological diseases in which autoreactive T cells have an active role in pathogenesis. In this review, we report on the recent progress in profiling and assessing the functionality of autoreactive T cells in central nervous system (CNS) autoimmune disorders that are currently postulated to be primarily T cell driven. We also explore the autoreactive T cell response in a recently emerging group of syndromes characterized by autoantibodies against neuronal cell-surface proteins. Common methodology implemented in T cell biology is further considered as it is an important determinant in their detection and characterization. An improved understanding of the contribution of autoreactive T cells expands our knowledge of the autoimmune response in CNS disorders and can offer novel methods of therapeutic intervention.

Utility of CSF Cytokine/Chemokines as Markers of Active Intrathecal Inflammation: Comparison of Demyelinating, Anti-NMDAR and Enteroviral Encephalitis

Background

Despite the discovery of CSF and serum diagnostic autoantibodies in autoimmune encephalitis, there are still very limited CSF biomarkers for diagnostic and monitoring purposes in children with inflammatory or autoimmune brain disease. The cause of encephalitis is unknown in up to a third of encephalitis cohorts, and it is important to differentiate infective from autoimmune encephalitis given the therapeutic implications.

Aim

To study CSF cytokines and chemokines as diagnostic biomarkers of active neuroinflammation, and assess their role in differentiating demyelinating, autoimmune, and viral encephalitis.

Methods

We measured and compared 32 cytokine/chemokines using multiplex immunoassay and APRIL and BAFF using ELISA in CSF collected prior to commencing treatment from paediatric patients with confirmed acute disseminated encephalomyelitis (ADEM, n = 16), anti-NMDAR encephalitis (anti-NMDAR E, n = 11), and enteroviral encephalitis (EVE, n = 16). We generated normative data using CSF from 20 non-inflammatory neurological controls. The sensitivity of CSF cytokine/chemokines to diagnose encephalitis cases was calculated using 95^th centile of control values as cut off. We correlated CSF cytokine/chemokines with disease severity and follow up outcome based on modified Rankin scale. One-way hierarchical correlational cluster analysis of molecules was performed in different encephalitis and outcome groups.

Results

In descending order, CSF TNF-α, IL-10, IFN-α, IL-6, CXCL13 and CXCL10 had the best sensitivity (>79.1%) when all encephalitis patients were included. The combination of IL-6 and IFN-α was most predictive of inflammation on multiple logistic regression with area under the ROC curve 0.99 (CI 0.97–1.00). There were no differences in CSF cytokine concentrations between EVE and anti-NMDAR E, whereas ADEM showed more pronounced elevation of Th17 related (IL-17, IL-21) and Th2 (IL-4, CCL17) related cytokine/chemokines. Unlike EVE, heat map analysis showed similar clustering of cytokine/chemokine molecules in immune mediated encephalitis (ADEM and anti-NMDAR E). Th1 and B cell (CXCL13 and CXCL10) molecules clustered together in patients with severe encephalopathy at admission and worse disability at follow up in all encephalitis. There was no correlation between CSF neopterin and IFN-γ or IFN-α.

Conclusion

A combination panel of cytokine/chemokines consisting of CSF TNF-α, IL-10, IFN-α, IL-6, CXCL13 and CXCL10 measured using multiplex immunoassay may be used to diagnose and monitor intrathecal inflammation in the brain. Given their association with worse outcome, certain key chemokines (CXCL13, CXCL10) could represent potential therapeutic targets in encephalitis.

B Cell, Th17, and Neutrophil Related Cerebrospinal Fluid Cytokine/Chemokines Are Elevated in MOG Antibody Associated Demyelination

BACKGROUND

Myelin oligodendrocyte glycoprotein antibody (MOG Ab) associated demyelination represents a subgroup of autoimmune demyelination that is separate from multiple sclerosis and aquaporin 4 IgG-positive NMO, and can have a relapsing course. Unlike NMO and MS, there is a paucity of literature on immunopathology and CSF cytokine/chemokines in MOG Ab associated demyelination.

AIM

To study the differences in immunopathogenesis based on cytokine/chemokine profile in MOG Ab-positive (POS) and -negative (NEG) groups.

METHODS

We measured 34 cytokines/chemokines using multiplex immunoassay in CSF collected from paediatric patients with serum MOG Ab POS [acute disseminated encephalomyelitis (ADEM = 8), transverse myelitis (TM = 2) n = 10] and serum MOG Ab NEG (ADEM = 5, TM = 4, n = 9) demyelination. We generated normative data using CSF from 20 non-inflammatory neurological controls.

RESULTS

The CSF cytokine and chemokine levels were higher in both MOG Ab POS and MOG Ab NEG demyelination groups compared to controls. The CSF in MOG Ab POS patients showed predominant elevation of B cell related cytokines/chemokines (CXCL13, APRIL, BAFF and CCL19) as well as some of Th17 related cytokines (IL-6 AND G-CSF) compared to MOG Ab NEG group (all p<0.01). In addition, patients with elevated CSF MOG antibodies had higher CSF CXCL13, CXCL12, CCL19, IL-17A and G-CSF than patients without CSF MOG antibodies.

CONCLUSION

Our findings suggest that MOG Ab POS patients have a more pronounced CNS inflammatory response with elevation of predominant humoral associated cytokines/chemokines, as well as some Th 17 and neutrophil related cytokines/chemokines suggesting a differential inflammatory pathogenesis associated with MOG antibody seropositivity. This cytokine/chemokine profiling provides new insight into disease pathogenesis, and improves our ability to monitor inflammation and response to treatment. In addition, some of these molecules may represent potential immunomodulatory targets.

Increased interleukin-6 correlates with myelin oligodendrocyte glycoprotein antibodies in pediatric monophasic demyelinating diseases and multiple sclerosis

Acquired demyelinating syndromes (ADS) in children evolve either as a monophasic disease diagnosed as acute demyelinating encephalomyelitis (ADEM), transverse myelitis (TM) or optic neuritis (ON), or a multiphasic one with several relapses most often leading to the diagnosis of multiple sclerosis (MS) or neuromyelitis optica (NMO). These neuroinflammatory disorders are increasingly associated with autoantibodies against proteins such as aquaporin-4 in rare instances, and more frequently against myelin oligodendrocyte glycoprotein (MOG). Recently, in adult NMO patients, C5a levels were shown to be elevated in cerebrospinal fluid (CSF) during acute exacerbation. We investigated the CSF levels of anaphylatoxins and pro-inflammatory cytokines, and plasma MOG antibodies in onset samples from children with ADS. Thirty four children presenting with a first episode of ADS, 17 with monophasic ADS (9 with ADEM, 4 with TM and 4 with ON) and 17 with MS, who had paired blood and CSF samples at onset were included and compared to 12 patients with other non-inflammatory neurological disorders (OND). Cytokines and anaphylatoxins in CSF were measured by Cytometric Bead Array immunoassay. MOG antibody titers in plasma were tested by flow cytometry using a stable cell line expressing full-length human MOG. We found a significant increase in C5a levels in the CSF of patients with monophasic ADS (n=17) compared to OND (n=12, p=0.0036) and to MS (n=17, p=0.0371). The C5a levels in MS were higher than in OND without reaching significance (p=0.2). CSF IL-6 levels were significantly increased in monophasic ADS compared to OND (p=0.0027) and to MS (p=0.0046). MOG antibody plasma levels were significantly higher in monophasic ADS (p<0.0001) and, to a lesser extent, in MS compared to OND (p=0.0023). Plasma MOG antibodies and CSF IL-6 levels were significantly correlated (r=0.51, p=0.018). CSF C5a and IL-6 levels are increased in monophasic ADS but not in MS when compared to OND, suggesting that these markers may help to predict monophasic or relapsing fate of ADS at onset. MOG antibody titers, which were higher in monophasic ADS than in MS, correlated with IL-6 levels, but not with C5a, suggesting an association between MOG antibodies and neuroinflammation in pediatric ADS.

Acute disseminated encephalomyelitis associated with hepatitis B virus reinfection--consequence or coincidence?

Acute disseminated encephalomyelitis (ADEM) is an idiopathic inflammatory demyelinating disease of the CNS that is particularly difficult to differentiate from the first episode of multiple sclerosis. ADEM typically occurs as a post-infectious phenomenon, and usually presents a monophasic episode, but also includes recurrent and multiphasic forms. We report a case of ADEM associated with hepatitis B virus (HBV) reinfection. After steroid and IV immunoglobulin treatment, neurologic symptoms were improved. We suppose that the HBV reinfection was the cause of ADEM, but possible pathogenetic mechanism is still obscure.

Acute disseminated encephalomyelitis

Acute disseminated encephalomyelitis (ADEM) is an acute multifocal demyelinating disease of the central nervous system that typically follows an infectious illness. Its clinical course in most cases is monophasic; however, relapsing ADEM is rarely seen, which poses a diagnostic challenge for distinguishing this disease from multiple sclerosis (MS). Although typically encountered in children, it also occurs in adults with disease characteristics slightly different from the pediatric cases. Formerly, ADEM occurred particularly often in children with measles. However, the illness most often follows a non-descript viral or even bacterial infectious illness. ADEM occurs throughout the world, and may even be more common in less-developed countries, where MS is rare, than in developed ones, where MS is common. Children seldom get MS as opposed to adults, indicating that ADEM constitutes a distinct entity from MS. The prognosis of ADEM is generally good, but severe neurologic sequelae after ADEM are occasionally seen. In this chapter, the etiology, clinical/laboratory/radiologic characteristics, treatment options, and prognosis of ADEM are discussed.

Acute disseminated encephalomyelitis

Acute disseminated encephalomyelitis is an immune-mediated inflammatory and demyelinating disorder of the central nervous system, commonly preceded by an infection. It principally involves the white matter tracts of the cerebral hemispheres, brainstem, optic nerves, and spinal cord. Acute disseminated encephalomyelitis mainly affects children. Clinically, patients present with multifocal neurologic abnormalities reflecting the widespread involvement in central nervous system. Cerebrospinal fluid may be normal or may show a mild pleocytosis with or without elevated protein levels. Magnetic resonance image (MRI) shows multiple demyelinating lesions. The diagnosis of acute disseminated encephalomyelitis requires both multifocal involvement and encephalopathy by consensus criteria. Acute disseminated encephalomyelitis typically has a monophasic course with a favorable prognosis. Multiphasic forms have been reported, resulting in diagnostic difficulties in distinguishing these cases from multiple sclerosis. In addition, many inflammatory disorders may have a similar presentation with frequent occurrence of encephalopathy and should be considered in the differential diagnosis of acute disseminated encephalomyelitis.

Post-traumatic acute disseminated encephalomyelitis

A 23-year-old black African male fell and bumped his head from a tackle while playing soccer. He subsequently became blind from optic neuritis. An MRI of the brain showed white-matter changes suggestive of acute disseminated encephalomyelitis (ADEM). MR spectroscopy of the brain showed a demyelination pattern. This case report brings to the fore unsettled questions about ADEM, among them being whether it can occur as a post-traumatic event.

Pediatric central nervous system inflammatory demyelination: acute disseminated encephalomyelitis, clinically isolated syndromes, neuromyelitis optica, and multiple sclerosis

PURPOSE OF REVIEW

We review the recent consensus definitions for acute disseminated encephalomyelitis,clinically isolated syndromes, neuromyelitis optica, and multiple sclerosis (MS) in children. We also discuss the importance of clinically defined consistency, the need for biomarker-based patient delineation, the likelihood of subsequent MS diagnosis following acute demyelination, and current therapeutic options.

RECENT FINDINGS

Studies of children after a first episode of demyelination have identified disease onset in adolescence, intrathecal oligoclonal bands and optic neuritis as associated with a higher MS risk, whereas prepubertal onset, presence of polyfocal features with encephalopathy, and transverse myelitis have been associated with a lower risk of subsequent MS. The relapsing-remitting form of MS accounts for over 96% of all MS in children. Neuromyelitis optica appears to be a distinct clinical and biological entity for which neuromyelitis optica IgG provides a high degree of specificity. Neuroimaging plays a key role in the diagnosis of acute demyelination, and serial imaging can provide evidence of lesion dissemination in time that can confirm a diagnosis of MS even in the absence of clinical relapse.

SUMMARY

Although clinical definitions, increased awareness, and MRI have contributed to the increasing identification of acute demyelination and MS in children, challenges remain in predicting MS risk. Identification of reliable biomarkers or application of more advanced neuroimaging techniques would serve as invaluable tools to distinguish monophasic demyelination from the first attack of MS.

Cytokines and chemokines in cerebrospinal fluid and serum of adult patients with acute disseminated encephalomyelitis

Cytokines and chemokines contribute to the pathogenesis of acute disseminated encephalomyelitis (ADEM). Using a multiplex immunochemiluminescence ELISA, we measured 8 Th1/Th2 cytokines and 18 chemokines in the cerebrospinal fluid (CSF) and serum of 17 ADEM patients, 14 multiple sclerosis (MS) patients, and 7 healthy controls (HCs). Relative to HCs, ADEM patients had significantly high mean CSF concentrations of chemokines with attractant/activating properties towards neutrophils (CXCL1 and CXCL7), monocytes/T cells (CCL3 and CCL5), Th1 cells (CXCL10), and Th2 cells (CCL1, CCL22, and CCL17). Mean CSF concentrations of CXCL7, CCL1, CCL22, and CCL17 were higher in ADEM than in MS, whereas those of CCL11 were lower in MS than in ADEM and HCs. CSF pleocytosis correlated with CSF concentrations of CXCL1, CXCL10, CCL1, CCL17, and CCL22. Most of the functionally homologous chemokines correlated with each other. CSF Th1/Th2 cytokines were not detectable in most samples. Their mean concentrations did not differ in the three groups, and the same held for serum cytokines and chemokines. Our data suggest that the upregulation of chemokines active on neutrophils and Th2 cells differentiates ADEM from MS inflammation, and that both Th1 and Th2 chemokines might be produced in ADEM. Chemokines upregulated in ADEM could become CSF biomarkers after a posteriori evaluations in unselected case series.

CSF cytokine and chemokine profiles in acute disseminated encephalomyelitis

We simultaneously measured 16 cytokines/chemokines in cerebrospinal fluid (CSF) from 14 patients with acute disseminated encephalomyelitis (ADEM) and 20 controls using a fluorescent bead-based immunoassay. A variety of cytokines, such as IL-1beta, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IFN-gamma, TNF-alpha, G-CSF and MIP-1beta, were significantly elevated in ADEM. In particular, G-CSF showed a marked 38-fold increase compared to the control mean. Significant positive correlations with inflammatory parameters in CSF, such as cell counts and protein levels, were found for IFN-gamma, IL-6 and IL-8. In contrast, IL-17 produced by activated CD4(+) memory T cells was not increased. The results suggested that various cytokines related to activation of macrophages/microglias and Th(1) and Th(2) cells are upregulated in CSF in ADEM.

Unveiling the enigma of the CNS as a B-cell fostering environment

This Opinion deals with the apparent paradox between the 'immune privileged' status of the central nervous system (CNS) and its propensity to act as a B-cell fostering environment in a variety of neurological disorders. Evidence will be reviewed that: (i) molecules regulating B-cell homing and survival are produced in the CNS, (ii) in different neuroinflammatory diseases, B cells can undergo a local recapitulation of the differentiation occurring in secondary lymphoid organs and (iii) ectopic lymphoid follicles develop in the meninges of multiple sclerosis (MS) patients.

Soluble adhesion molecules in acute disseminated encephalomyelitis

Soluble adhesion molecules are overexpressed in neuroinflammatory disorders. Their synthesis parallels that of their membrane-bound counterparts, which modulate lymphocyte transmigration through the blood-brain barrier. Blood-brain barrier cellular migration may be essential in the evolution of postinfectious inflammatory central nervous system disease. The serum levels of soluble intercellular adhesion molecule-1, soluble vascular adhesion molecule-1, and soluble E-selectin were measured in 12 children with acute disseminated encephalomyelitis and in two control groups (35 healthy and 35 affected by noninflammatory neurologic diseases) of similar age. In patients with acute disseminated encephalomyelitis, soluble E-selectin serum levels were significantly higher (median 113 ng/mL, range 54-144) than in both control groups (median 44, range 31-63, and median 58, range 43-89, respectively; one-way analysis of variance, P < 0.0001); a statistical trend for higher levels of soluble intercellular adhesion molecule-1 was observed in acute disseminated encephalomyelitis subjects, whereas soluble vascular adhesion molecule-1 titers did not differ between the three groups. The specific role played by each of these molecules in lymphocyte extravasation and the differential cytokine modulation of their expression might explain the result. Further larger studies are required including serial measurements and cerebrospinal fluid analysis.

Pediatric central nervous system infections and inflammatory white matter disease

This article reviews the immunology of the central nervous system and the clinical presentation, diagnosis, and treatment of children with viral or parainfectious encephalitis. The emphasis is on the early recognition of treatable causes of viral encephalitis (herpes simplex virus), and the diagnosis and treatment of acute disseminated encephalomyelitis are described in detail. Laboratory and imaging findings in the two conditions also are described.

Toward the definition of acute disseminated encephalitis of childhood

PURPOSE OF REVIEW

Acute disseminated encephalomyelitis (ADEM) is a demyelinating disorder most common in childhood and adolescence and thought to have an immune pathogenesis. Some children with ADEM develop additional temporally remote episodes of demyelination with localizations that differ from those of the initial episode and multiple sclerosis is diagnosed. Others have only a single episode. Still others have recurrent episodes in temporal proximity to or with the same localizations as the initial presentation. This review is aimed at delineating what will be required to arrive at a definition of ADEM so as to distinguish it from childhood multiple sclerosis on first presentation.

RECENT FINDINGS

All studies to date aimed at differential characterization of ADEM and childhood multiple sclerosis have been retrospective case reviews. Each has examined a different array of historical, physical examination, laboratory, and radiologic characteristics of a differently defined patient population.

SUMMARY

Defining ADEM and distinguishing it from multiple sclerosis early in the course of the latter disease depends critically on standardization of prospective, multicenter study design, execution, and data analysis. This has become of paramount importance, as preventive therapies have evolved for recurrent attacks of multiple sclerosis.

Acute disseminated encephalomyelitis in childhood: epidemiologic, clinical and laboratory features

BACKGROUND

Acute disseminated encephalomyelitis (ADEM) is a central nervous system demyelinating disease that usually follows an apparently benign infection in otherwise healthy young persons. The epidemiology, infectious antecedents and pathogenesis of ADEM are poorly characterized, and some ADEM patients are subsequently diagnosed with multiple sclerosis (MS).

METHODS

We retrospectively (1991-1998) and prospectively (1998-2000) studied all persons aged < 20 years diagnosed with ADEM from the 3 principal pediatric hospitals in San Diego County, CA, during 1991-2000. Acute neurologic abnormalities and imaging evidence of demyelination were required for study inclusion. Epidemiologic variables, risk factors, clinical course, laboratory and radiographic findings, neuropathology and treatment data were analyzed. Interleukin (IL)-12, interferon-gamma (IFN-gamma) and IL-10 were assayed in blinded manner on cerebrospinal fluid (CSF) obtained prospectively from a subset of ADEM cases and compared with CSF from patients with enteroviral (EV) meningoencephalitis confirmed by polymerase chain reaction (PCR) and controls without pleocytosis.

RESULTS

Data were analyzed on 42 children and adolescents diagnosed with ADEM during 1991-2000, and CSF IL-12, IFN-gamma and IL-10 levels were compared among ADEM (n = 14), EV meningoencephalitis (n = 14) and controls without pleocytosis (n = 28). Overall incidence of ADEM was 0.4/100,000/year; incidence quadrupled during 1998-2000 compared with earlier years. No gender, age stratum, ethnic group or geographic area was disproportionately affected. A total of 4 (9.5%) patients initially diagnosed with ADEM were subsequently diagnosed with MS after multiple episodes of demyelination. Although most children eventually recovered, 2 died, including 1 of the 3 ultimately diagnosed with MS. Magnetic resonance imaging was required for diagnosis among 74% of patients; computerized tomography findings were usually normal. Patients with EV had significantly higher mean CSF IFN-gamma (P = 0.005) and IL-10 (P = 0.05) than patients with ADEM and controls without CSF pleocytosis. CSF from ADEM patients had CSF cytokine values statistically similar to those of 3 patients subsequently diagnosed with MS.

CONCLUSIONS

ADEM is a potentially severe demyelinating disorder likely to be increasingly diagnosed as more magnetic resonance imaging studies are performed on patients with acute encephalopathy. Further characterization of the central nervous system inflammatory response will be needed to understand ADEM pathogenesis, to improve diagnostic and treatment strategies and to distinguish ADEM from MS.

What is acute disseminated encephalomyelitis (ADEM)?

Acute demyelinating encephalomyelitis (ADEM) is increasingly recognized but difficult to define precisely: eleven papers have recently been published that used different definitions. Several diseases, most of them relapsing, can mimic ADEM at onset and require specific treatments. First, the distinction between early signs of multiple sclerosis and ADEM is controversial in the absence of specific biological characterization. To clarify it, epidemiological evaluations on large groups of children, of calculated risk factors for the occurrence of relapses after a first demyelinating event are probably the best approach. Macrophage activation syndrome and different types of angiitis may mimic ADEM, because they can occur in the absence of the usual non neurological symptoms. Both entities require specific treatments.