Immune-mediated myelopathies

PURPOSE OF REVIEW

This article presents data about inflammatory myelopathies, also referred to as transverse myelitis. While the idiopathic form of this condition is rare, the prevalence of transverse myelitis is relatively common when including all of the secondary causes, such as multiple sclerosis (MS). Thus, clinicians and researchers should be familiar with the presentations, diagnostic algorithms, treatment options, and long-term symptom management for patients with transverse myelitis. This review presents data about the idiopathic and secondary forms of transverse myelitis.

RECENT FINDINGS

As research has expanded, the presentations of transverse myelitis have been clarified and the secondary causes explored. With the identification of the aquaporin-4 (AQP4) antibody, more patients with transverse myelitis have been categorized as having neuromyelitis optica (NMO), and more variable presentations have been published. A growing experience with various treatment options has expanded the therapeutic approaches to acute inflammatory myelopathies beyond standard corticosteroid intervention regimens.

SUMMARY

Transverse myelitis can occur in isolation or as part of a larger systemic condition. An empiric approach to patient evaluation can accelerate diagnosis of secondary conditions. Mounting evidence suggests that an aggressive approach to therapy can improve patient outcomes, but large-scale prospective trials are lacking.

Ocular motor signatures of cognitive dysfunction in multiple sclerosis

The anatomical and functional overlap between ocular motor command circuitry and the higher-order networks that form the scaffolding for cognition makes for a compelling hypothesis that measures of ocular motility could provide a means to sensitively interrogate cognitive dysfunction in people with multiple sclerosis (MS). Such an approach may ultimately provide objective and reproducible measures of cognitive dysfunction that offer an innovative capability to refine diagnosis, improve prognostication, and more accurately codify disease burden. A further dividend may be the validation and application of biomarkers that can be used in studies aimed at identifying and monitoring preventative, protective and even restorative properties of novel neurotherapeutics in MS. This Review discusses the utility of ocular motor measures in patients with MS to characterize disruption to wide-ranging networks that support cognitive function.

Outer retinal changes following acute optic neuritis

BACKGROUND

Retinal nerve fiber and ganglion cell+inner plexiform (GCIP) layer thinning following multiple sclerosis-related acute optic neuritis (AON) is well described. However, whether AON results in changes in the inner nuclear (INL), outer plexiform (OPL), outer nuclear (ONL) and/or photoreceptor segment (PS) layers remains undetermined.

OBJECTIVES

The objective of this paper is to determine if INL+OPL and/or ONL+PS changes occur following AON.

METHODS

Thirty-three AON patients underwent serial optical coherence tomography (OCT) and visual function testing (mean follow-up: 25 months). Longitudinal changes in retinal layer thickness were analyzed using mixed-effects linear regression.

RESULTS

Four months following AON, the mean decrease in GCIP thickness relative to baseline was 11.4% (p < 0.001). At four months, a concomitant 3.4% increase in average ONL+PS thickness was observed (p < 0.001). The percentage decrease in GCIP thickness and increase in ONL+PS thickness were strongly correlated (r = -0.70; p < 0.001). Between months 4 to 12, ONL+PS thickness declined and, at 12 months, was no longer significantly different from baseline (mean change: 0.5%; p = 0.37). Similar, albeit less robust, changes in the INL+OPL were observed.

CONCLUSIONS

Following AON, dynamic changes occur in the deep retinal layers, which are proportional to GCIP thinning. These novel findings help further our understanding of the biological and/or anatomical sequelae resulting from AON.

Re-evaluating the treatment of acute optic neuritis

Clinical case reports and prospective trials have demonstrated a reproducible benefit of hypothalamic-pituitary-adrenal (HPA) axis modulation on the rate of recovery from acute inflammatory central nervous system (CNS) demyelination. As a result, corticosteroid preparations and adrenocorticotrophic hormones are the current mainstays of therapy for the treatment of acute optic neuritis (AON) and acute demyelination in multiple sclerosis.Despite facilitating the pace of recovery, HPA axis modulation and corticosteroids have failed to demonstrate long-term benefit on functional recovery. After AON, patients frequently report visual problems, motion perception difficulties and abnormal depth perception despite 'normal' (20/20) vision. In light of this disparity, the efficacy of these and other therapies for acute demyelination require re-evaluation using modern, high-precision paraclinical tools capable of monitoring tissue injury.In no arena is this more amenable than AON, where a new array of tools in retinal imaging and electrophysiology has advanced our ability to measure the anatomic and functional consequences of optic nerve injury. As a result, AON provides a unique clinical model for evaluating the treatment response of the derivative elements of acute inflammatory CNS injury: demyelination, axonal injury and neuronal degeneration.In this article, we examine current thinking on the mechanisms of immune injury in AON, discuss novel technologies for the assessment of optic nerve structure and function, and assess current and future treatment modalities. The primary aim is to develop a framework for rigorously evaluating interventions in AON and to assess their ability to preserve tissue architecture, re-establish normal physiology and restore optimal neurological function.

Aquatic training in MS: neurotherapeutic impact upon quality of life

Three fundamental principals associated with aquatic therapy differentiate it with respect to exercise on land, and in air. These are buoyancy (reduction in weight of the body within the buoyant medium of water), viscosity (a “drag force” is generated when moving within water, when compared with the same movement in air), and the thermodynamic aspect of water exercise, during which the heat capacity of water is about 1000 times greater than that of an equivalent amount of air; equating to a heat transfer from the body into water at a rate 25 times faster than that of air. Aquatic conditioning, can improve neurologic functioning, with dividends favorably impacting activities of daily living, health maintenance, safety, and ultimately quality of life. Here, we review the application of aquatic exercise training in MS patients.

Ocular motor measures of cognitive dysfunction in multiple sclerosis II: working memory

Our companion paper documents pervasive inhibitory deficits in multiple sclerosis (MS) using ocular motor (OM) measures. Here we investigated the utility of an OM working memory (WMem) task in characterising WMem deficits in these patients as a function of disease status and disease duration. 22 patients with CIS, 22 early clinically definite MS patients (CDMS: <7 years of diagnosis), 22 late CDMS patients (>7 years from diagnosis), and 22 healthy controls participated. All participants completed the ocular motor WMem task, the paced auditory serial addition test (PASAT), and the symbol digit modalities test (SDMT). Clinical disability was characterised in CDMS patients using the Expanded Disability Severity Scale (EDSS). WMem performance was measured as proportion of errors (WMem errors), saccade latency, and relative sensitivity to WMem loading (WMem effect), an indicator of WMem capacity. All patient groups performed more WMem errors than controls with proportion of WMem errors, and degree of WMem effect increasing with increasing disease duration. A larger WMem effect, reflecting poorer WMem capacity, corresponded to poorer performance on neuropsychological measures, and a higher disability score for CDMS patients with the longest disease duration; an observation that suggests wider implication of WMem executive processes with advancing disease. Conspicuously, performance decrements on standard neuropsychological testing did not similarly increase commensurate with disease duration. The ocular motor WMem task appears to meaningfully dissociate WMem deficit from healthy individuals as well as a function of increasing disease duration. Potentially, this task represents a highly informative and objective method by which to ascertain progressive WMem changes from the earliest inception of MS.

The effect of glatiramer acetate therapy on functional properties of B cells from patients with relapsing-remitting multiple sclerosis

IMPORTANCE

This study describes what is, to our knowledge, the previously unknown effect of glatiramer acetate therapy on B cells in patients with relapsing-remitting multiple sclerosis (MS).

OBJECTIVE

To determine whether glatiramer acetate therapy normalizes dysregulated B-cell proliferation and cytokine production in patients with MS.

DESIGN, SETTING, AND PARTICIPANTS

Twenty-two patients with MS who were receiving glatiramer acetate therapy and 22 treatment-naive patients with MS were recruited at The University of Texas Southwestern Medical Center MS clinic. Cell samples from healthy donors were obtained from HemaCare (Van Nuys, California) or Carter Blood Bank (Dallas, Texas). Treatment-naive patients with MS had not received any disease-modifying therapies for at least 3 months before the study.

EXPOSURES

Glatiramer acetate therapy for at least 3 months at the time of the study.

MAIN OUTCOMES AND MEASURES

B-cell phenotype and proliferation and immunoglobulin and cytokine secretion.

RESULTS

A restoration of interleukin 10 production by peripheral B cells was observed in patients undergoing glatiramer acetate therapy as well as a significant reduction of interleukin 6 production in a subset of patients who received therapy for less than 32 months. Furthermore, proliferation in response to high-dose CD40L was altered and immunoglobulin production was elevated in in vitro-activated B cells obtained from patients who received glatiramer acetate.

CONCLUSIONS AND RELEVANCE

Glatiramer acetate therapy remodels the composition of the B-cell compartment and influences cytokine secretion and immunoglobulin production. These data suggest that glatiramer acetate therapy affects several aspects of dysregulated B-cell function in MS that may contribute to the therapeutic mechanisms of glatiramer acetate.

Retinal damage and vision loss in African American multiple sclerosis patients

OBJECTIVE

To determine whether African American (AA) multiple sclerosis (MS) patients exhibit more retinal damage and visual impairment compared to Caucasian American (CA) MS patients.

METHODS

A total of 687 MS patients (81 AAs) and 110 healthy control (HC) subjects (14 AAs) were recruited at 3 academic hospitals between 2008 and 2012. Using mixed effects regression models, we compared high- and low-contrast visual acuity (HCVA and LCVA) and high-definition spectral domain optical coherence tomography measures of retinal architecture between MS patients of self-identified AA and CA ancestry.

RESULTS

In HCs, baseline peripapillary retinal nerve fiber layer (RNFL) thickness was 6.1µm greater in AAs (p = 0.047), whereas ganglion cell/inner plexiform layer (GCIP) thickness did not differ by race. In MS patients, baseline RNFL did not differ by race, and GCIP was 3.98µm thinner in AAs (p = 0.004). AAs had faster RNFL and GCIP thinning rates compared to CAs (p = 0.004 and p = 0.046, respectively). AA MS patients had lower baseline HCVA (p = 0.02) and worse LCVA per year of disease duration (p = 0.039). Among patients with an acute optic neuritis (AON) history, AAs had greater loss of HCVA than CA patients (p = 0.012).

INTERPRETATION

This multicenter investigation provides objective evidence that AA MS patients exhibit accelerated retinal damage compared to CA MS patients. Self-identified AA ancestry is associated with worse MS-related visual disability, particularly in the context of an AON history, suggesting a more aggressive inflammatory disease course among AA MS patients or a subpopulation therein.

JC virus in CD34+ and CD19+ cells in patients with multiple sclerosis treated with natalizumab

IMPORTANCE

Infection with JC virus (JCV) may lead to development of demyelinating progressive multifocal leukoencephalopathy in patients with multiple sclerosis (MS) who are treated with natalizumab.

OBJECTIVE

To determine whether mononuclear cells in circulation from MS patients treated with natalizumab harbor JCV DNA.

DESIGN, SETTING, AND PARTICIPANTS

In this prospective investigation, we enrolled 49 MS patients from the Clinical Center for Multiple Sclerosis at The University of Texas Southwestern Medical Center and 18 healthy volunteers. We drew 120-mL blood samples from 26 MS patients at baseline and at approximately 3-month intervals to 10 months during the course of natalizumab infusions. One blood sample was drawn from 23 MS patients receiving natalizumab for more than 24 months and from 18 healthy volunteers.

INTERVENTIONS

Natalizumab treatment of MS.

MAIN OUTCOMES AND MEASURES

The blood samples were separated using flow cytometry into CD34+, CD19+, and CD3+ cell subsets; DNA templates were prepared using quantitative polymerase chain reaction for JCV DNA identification. Plasma samples were tested for anti-JCV antibodies by enzyme-linked immunosorbent assays performed at the Laboratory of Molecular Medicine and Neuroscience, National Institute of Neurological and Communicative Diseases and Stroke.

RESULTS

Thirteen of the 26 patients (50%) with baseline and follow-up blood samples had detectable viral DNA in at least 1 cell compartment at 1 or more points. Ten of the 23 patients (44%) receiving treatment for more than 24 months and 3 of the 18 healthy volunteers (17%) also had detectable viral DNA in 1 or more cell compartment. Fifteen of the 49 MS patients (31%) were confirmed to harbor JCV in CD34+ cells and 12 of 49 (24%) in CD19+ cells. Only 1 of 18 healthy volunteers were viremic in CD34+ cells and none in CD19+ cells. Nine patients and 1 healthy volunteer were viremic but had seronegative test results for JCV antibodies.

CONCLUSIONS AND RELEVANCE

JC virus DNA was detectable within cell compartments of natalizumab-treated MS patients after treatment inception and longer. JC virus DNA may harbor in CD34+ cells in bone marrow that mobilize into the peripheral circulation at high concentrations. Latently infected cells initiate differentiation to CD19+ cells that favors growth of JCV. These data link the mechanism of natalizumab treatment with progressive multifocal leukoencephalopathy.

Monocular and binocular low-contrast visual acuity and optical coherence tomography in pediatric multiple sclerosis

BACKGROUND

Low-contrast letter acuity and optical coherence tomography (OCT) capture visual dysfunction and axonal loss in adult-onset multiple sclerosis (MS), and have been proposed as secondary outcome metrics for therapeutic trials. Clinical trials will soon be launched in pediatric MS, but such outcome metrics have not been well-validated in this population.

OBJECTIVES

To determine whether MS onset during childhood and adolescence is associated with measurable loss of visual acuity and thinning of the retinal nerve fiber layer (RNFL), whether such features are noted only in the context of clinical optic nerve inflammation (optic neuritis, ON) or are a feature of MS even in the absence of optic nerve relapses, and to define the optimal methods for such detection.

STUDY DESIGN

Cross-sectional study.

METHODS

Monocular and binocular high- and low-contrast letter acuity and contrast sensitivity were assessed in a cross-sectional cohort of children (ages 5 to 17 years) with MS (N=22 patients, 44 eyes; 8 patients with a history of ON) and disease-free controls (N=29 patients; 58 eyes) from three academic centers. Binocular summation was determined by calculating the number of letters correctly identified using the binocular score minus the better eye score for each visual test. RNFL thickness was measured using OCT (Stratus OCT-3). Results were analyzed in terms of "eyes" as: MS ON+, MS ON-, and control eyes. Generalized estimating equation (GEE) regression models were used to compare patients to controls.

RESULTS

Traditional high-contrast visual acuity scores did not differ between MS ON+, MS ON-, and controls eyes. MS ON+ eyes had decreased monocular (p<0.001) and decreased binocular (p=0.007) low-contrast letter acuity (Sloan 1.25% contrast charts) scores. Monocular visual acuity did not differ when comparing MS ON- and control eyes. The magnitude of binocular summation using low-contrast charts was similar for pediatric MS participants and controls and was not diminished in children with a history of ON. While the mean RNFL thickness for all MS eyes (103±17 μm) trended lower when compared to corresponding measures in control eyes (109±9 μm, p=0.085), we confirmed a highly significant reduction in mean RNFL thickness in MS eyes with a history of ON (86±22 μm, p<0.001). RNFL thickness of MS ON- eyes in pediatric MS patients (109±11 μm) did not differ from controls (p=0.994).

CONCLUSIONS

Low-contrast letter acuity detects subtle visual loss in MS patients with prior ON, consistent with incomplete recovery, a finding further supported by RNFL loss in ON affected eyes. In MS patients with prior unilateral ON, binocular acuity is decreased; however, the magnitude of binocular summation is preserved, unlike adult-onset MS who exhibit a reduced capacity for visual compensation in the context of unilateral injury. Also unlike findings in adult-onset MS, we did not demonstrate RNFL thinning in ON- eyes of children and adolescents with MS. Further validation is required to confirm whether neurodegeneration of visual pathways occurs in the absence of relapse, and thus whether OCT will serve as a sensitive metric for such pathology in the pediatric and adolescent MS context.

Retinal architecture and mfERG: Optic nerve head component response characteristics in MS

OBJECTIVE

To describe a novel neurophysiologic signature of the retinal ganglion cell and to elucidate its relationship to abnormalities in validated structural and functional measures of the visual system.

METHODS

We used multifocal electroretinogram-generated optic nerve head component (ONHC) responses from normal subjects (n = 18), patients with multiple sclerosis (MS) (n = 18), and those with glaucoma (n = 3). We then characterized the relationship between ONHC response abnormalities and performance on low-contrast visual acuity, multifocal visual-evoked potential-induced cortical responses, and average and quadrant retinal nerve fiber layer (RNFL) thicknesses, as measured by spectral-domain optical coherence tomography.

RESULTS

Compared with the eyes of normal subjects, the eyes of patients with MS exhibited an increased number of abnormal or absent ONHC responses (p < 0.0001). For every 7-letter reduction in low-contrast letter acuity, there were corresponding 4.6 abnormal ONHC responses at 2.5% contrast (p < 0.0001) and 6.6 abnormalities at the 1.25% contrast level (p < 0.0001). Regarding average RNFL thickness, for each 10-μm thickness reduction, we correspondingly observed 6.8 abnormal ONHC responses (p = 0.0002). The most robust association was between RNFL thinning in the temporal quadrant and ONHC response abnormalities (p < 0.0001).

CONCLUSION

Further characterization of ONHC abnormalities (those that are reversible and irreversible) may contribute to the development of novel neurotherapeutic strategies aimed at achieving neuroprotective, and perhaps even neurorestorative, effects in disorders that target the CNS in general, and MS in particular.

Disease exacerbation of multiple sclerosis is characterized by loss of terminally differentiated autoregulatory CD8+ T cells

Multiple sclerosis (MS) is an inflammatory, demyelinating disease of the central nervous system (CNS). Although its etiology remains unknown, pathogenic T cells are thought to underlie MS immune pathology. We recently showed that MS patients harbor CNS-specific CD8+ Tregs that are deficient during disease relapse. We now demonstrate that CNS-specific CD8+ Tregs were cytolytic and could eliminate pathogenic CD4+ T cells. These CD8+ Tregs were present primarily in terminally differentiated (CD27-, CD45RO-) subset and their suppression was IFNγ, perforin and granzyme B-dependent. Interestingly, MS patients with acute relapse displayed a significant loss in terminally differentiated CD8+ T cells, with a concurrent loss in expression of perforin and granzyme B. Pre-treatment of exacerbation-derived CD8+ T cells with IL-12 significantly restored suppressive capability of these cells through upregulation of granzyme B. Our studies uncover immune-suppressive mechanisms of CNS-specific CD8+ Tregs, and may contribute to design of novel immune therapies for MS.

The menagerie of neurology: Animal signs and the refinement of clinical acumen

Neurology is a field known for "eponymophilia." While eponym use has been a controversial issue in medicine, animal-related metaphoric descriptions continue to flourish in neurologic practice, particularly with the advent of neuroimaging. To provide practicing and trainee neurologists with a useful reference for all these colorful eponyms, we performed a literature review and summarized the various animal eponyms in the practice of neurology (and their etiologic implications) to date. We believe that the ability to recognize animal-like attributes in clinical neurology and neuroradiology may be attributed to a visual phenomenon known as pareidolia. We propose that animal eponyms are a useful method of recognizing clinical and radiologic patterns that aid in the diagnostic process and therefore are effective aidesmémoire and communicative tools that enliven and improve the practice of neurology.

Optic nerve head component responses of the multifocal electroretinogram in MS

OBJECTIVE

To employ a novel stimulation paradigm in order to elicit multifocal electroretinography (mfERG)-induced optic nerve head component (ONHC) responses, believed to be contingent upon the transformation in electrical transmission properties of retinal ganglion cell axons from membrane to saltatory conduction mechanisms, as they traverse the lamina cribrosa and obtain oligodendrocyte myelin. We further sought to characterize abnormalities in ONHC responses in eyes from patients with multiple sclerosis (MS).

METHODS

In 10 normal subjects and 7 patients with MS (including eyes with and without a history of acute optic neuritis), we utilized a novel mfERG stimulation paradigm that included interleaved global flashes in order to elicit the ONHC responses from 103 retinal patches of pattern-reversal stimulation.

RESULTS

The number of abnormal or absent ONHC responses was significantly increased in MS patient eyes compared to normal subject eyes (p < 0.001, by general estimating equation modeling, and accounting for age and within-subject, intereye correlations).

CONCLUSION

Studying the relationship between ONHC abnormalities and alterations in validated structural and functional measures of the visual system may facilitate the ability to dissect and characterize the pathobiological mechanisms that contribute to tissue damage in MS, and may have utility to detect and monitor neuroprotective or restorative effects of novel therapies.

Relationships between retinal axonal and neuronal measures and global central nervous system pathology in multiple sclerosis

OBJECTIVE

To determine the relationships between conventional and segmentation-derived optical coherence tomography (OCT) retinal layer thickness measures with intracranial volume (a surrogate of head size) and brain substructure volumes in multiple sclerosis (MS).

DESIGN

Cross-sectional study.

SETTING

Johns Hopkins University, Baltimore, Maryland.

PARTICIPANTS

A total of 84 patients with MS and 24 healthy control subjects.

MAIN OUTCOME MEASURES

High-definition spectral-domain OCT conventional and automated segmentation-derived discrete retinal layer thicknesses and 3-T magnetic resonance imaging brain substructure volumes.

RESULTS

Peripapillary retinal nerve fiber layer as well as composite ganglion cell layer+inner plexiform layer thicknesses in the eyes of patients with MS without a history of optic neuritis were associated with cortical gray matter (P=.01 and P=.04, respectively) and caudate (P=.04 and P=.03, respectively) volumes. Inner nuclear layer thickness, also in eyes without a history of optic neuritis, was associated with fluid-attenuated inversion recovery lesion volume (P=.007) and inversely associated with normal-appearing white matter volume (P=.005) in relapsing-remitting MS. As intracranial volume was found to be related with several of the OCT measures in patients with MS and healthy control subjects and is already known to be associated with brain substructure volumes, all OCT-brain substructure relationships were adjusted for intracranial volume. CONCLUSIONS Retinal measures reflect global central nervous system pathology in multiple sclerosis, with thicknesses of discrete retinal layers each appearing to be associated with distinct central nervous system processes. Moreover, OCT measures appear to correlate with intracranial volume in patients with MS and healthy control subjects, an important unexpected factor unaccounted for in prior studies examining the relationships between peripapillary retinal nerve fiber layer thickness and brain substructure volumes.

In vivo identification of morphologic retinal abnormalities in neuromyelitis optica

OBJECTIVE

To assess eyes with neuromyelitis optica (NMO) for morphologic retinal abnormalities utilizing high-definition optical coherence tomography (OCT) imaging.

METHODS

In this cross-sectional study, 39 patients with NMO spectrum disorders and 39 age- and sex-matched healthy controls underwent spectral-domain OCT and visual function testing.

RESULTS

Microcystic macular edema (MME) of the inner nuclear layer (INL) was identified in 10 of 39 patients (26%) and was exclusively found in eyes with a history of optic neuritis (ON). MME eyes had lower high- and low-contrast letter-acuity scores (100%: p = 0.002; 2.5%: p = 0.002; 1.25%: p = 0.004), lower peripapillary retinal nerve fiber layer (RNFL) thickness (p = 0.04), lower macular RNFL thickness (p = 0.004), lower ganglion cell layer + inner plexiform layer (GCIP) thickness (p = 0.007), higher INL thickness (p < 0.001), and a greater number of ON episodes (p = 0.008) relative to non-MME eyes with a history of ON. After adjusting for history of multiple ON episodes, these findings remained significant for macular-RNFL thickness (p = 0.03), INL thickness (p < 0.001), and 100% and 2.5% contrast letter-acuity scores (p = 0.008 and p = 0.03, respectively). NMO spectrum eyes without ON history had lower macular RNFL thickness (p = 0.003), GCIP thickness (p = 0.002), outer nuclear layer thickness (p = 0.02), and low-contrast letter-acuity scores (2.5%: p = 0.03; 1.25%: p = 0.002) compared to healthy controls.

CONCLUSIONS

We have identified a pattern of retinal morphologic abnormalities in NMO that is associated with severe retinal axonal and neuronal loss and corresponding visual disability. MME may contribute to poor visual outcomes following NMO-associated ON or alternatively represent a marker of ON severity. Additionally, our results support that subclinical involvement of the anterior visual pathway may occur in NMO spectrum disorders.

Modulation of immune function occurs within hours of therapy initiation for multiple sclerosis

Daily administration of FDA-approved glatiramer acetate (GA) has beneficial effects on clinical course of relapsing remitting multiple sclerosis (RRMS). Although mechanisms of GA-action have been widely investigated and partially understood, immediate immune dynamics following GA-therapy are unknown. In the present study, we characterized the immediate effects of GA on phenotype, quantity and function of immune cells in MS patients. Prominent changes in immune cells were detected within 4-12h post-first GA-injection. T-cell modulation included significantly decreased CD4/CD8 ratio, perturbed homeostasis of predominantly CD8+ T-cells, significant enhancement in CD8+ T-cell mediated suppression and inhibitory potential of induced CD4-suppressors. Changes in APC were restricted to monocytes and included reduced stimulatory capacity in MLR and significantly increased IL-10 and TNF-α production. Our study provides the first evidence that GA treatment induces rapid immunologic changes within hours of first dose. Interestingly, these responses are not only restricted to innate immune cells but also include complex modulation of T-cell functionality.

Active MS is associated with accelerated retinal ganglion cell/inner plexiform layer thinning

OBJECTIVE

To determine the effect of clinical and radiologic disease activity on the rate of thinning of the ganglion cell/inner plexiform (GCIP) layer and the retinal nerve fiber layer in patients with multiple sclerosis (MS) using optical coherence tomography (OCT).

METHODS

One hundred sixty-four patients with MS and 59 healthy controls underwent spectral-domain OCT scans every 6 months for a mean follow-up period of 21.1 months. Baseline and annual contrast-enhanced brain MRIs were performed. Patients who developed optic neuritis during follow-up were excluded from analysis.

RESULTS

Patients with the following features of disease activity during follow-up had faster rates of annualized GCIP thinning: relapses (42% faster, p = 0.007), new gadolinium-enhancing lesions (54% faster, p < 0.001), and new T2 lesions (36% faster, p = 0.02). Annual GCIP thinning was 37% faster in those with disability progression during follow-up, and 43% faster in those with disease duration <5 years vs >5 years (p = 0.003). Annual rates of GCIP thinning were highest in patients exhibiting combinations of new gadolinium-enhancing lesions, new T2 lesions, and disease duration <5 years (70% faster in patients with vs without all 3 characteristics, p < 0.001).

CONCLUSIONS

MS patients with clinical and/or radiologic nonocular disease activity, particularly early in the disease course, exhibit accelerated GCIP thinning. Our findings suggest that retinal changes in MS reflect global CNS processes, and that OCT-derived GCIP thickness measures may have utility as an outcome measure for assessing neuroprotective agents, particularly in early, active MS.