Late-onset Tay-Sachs disease presenting with a neuromuscular phenotype-a case series.

BACKGROUND AND PURPOSE: Tay-Sachs disease is a rare and often fatal, autosomal recessive, lysosomal storage disease. Deficiency in ß-hexosaminidase leads to accumulation of GM2 ganglioside resulting in neuronal swelling and degeneration. Typical onset is in infancy with developmental regression and early death. Late-onset Tay-Sachs disease (LOTS) is extremely rare, especially in the non-Ashkenazi Jewish population, and is characterized by a more indolent presentation typically encompassing features of cerebellar and anterior horn cell dysfunction in addition to extrapyramidal and neuropsychiatric symptoms. CASES: A case series of four unrelated patients of non-Ashkenazi Jewish origin with a predominantly, and in some cases pure, neuromuscular phenotype with evidence of a motor neuronopathy on electromyography is presented. Cerebellar atrophy, reported to be a ubiquitous feature in LOTS, was absent in all patients. CONCLUSION: This case series provides evidence to support a pure neuromuscular phenotype in LOTS, which should be considered in the differential diagnosis of anterior horn cell disorders.

Impact of obstructive sleep apnoea on cognitive function in multiple sclerosis: A longitudinal study.

Cognitive impairment (CI) and fatigue are common in people with multiple sclerosis (MS), with well-known profound effects on quality of life. Sleep disorders, including obstructive sleep apnoea (OSA), are also common in MS patients. The presence of CI has previously been shown to strongly correlate with OSA diagnosed using polysomnography in MS. Treatment of OSA has not previously been investigated as a potential modality to improve cognition in MS patients. Therefore, we sought to investigate the potential effects of OSA treatment on both cognitive function and fatigue in MS patients. Twenty-three participants with MS reporting significant fatigue were enrolled. CI was assessed by the Brief International Cognitive Assessment in MS and the 3-second Paced Auditory Serial Addition Test. All participants underwent overnight polysomnography to assess for possible OSA. Cognitive and fatigue measures were repeated in those subsequently treated for OSA and in a comparative untreated sample. Seven participants (30%) had a diagnosis of OSA based on an apnoea-hypopnea index greater than 5 per hour, with no correlation between the presence of CI and OSA. Verbal learning at follow-up assessment was seen to improve significantly in those treated for OSA, compared with those who were not treated for a sleep disorder. This small study demonstrates the potential for OSA treatment to improve verbal learning in people with MS, larger studies are indicated to further investigate the potential for cognitive and fatigue improvement in people with MS through treatment of comorbid OSA.

IRAK1 Limits TLR3/4- and IFNAR-Driven IL-27 Production through a STAT1-Dependent Mechanism.

IL-27 is a cytokine exerting pleiotropic immunomodulatory effects on a broad spectrum of immune cells. Optimal IL-27 production downstream of TLR3/4 ligand stimulation relies on autocrine type I IFN signaling, defining a first and second phase in IL-27 production. This work shows that IL-1 receptor-associated kinase 1 (IRAK1) limits TLR3/4- and IFNAR-induced IL-27 production. At the mechanistic level, we identified IRAK1 as a novel regulator of STAT1, IRF1, and IRF9. We found hyperactivation of STAT1 together with increased nuclear levels of IRF1 and IRF9 in IRAK1-deficient murine macrophages compared with control cells following stimulation with LPS and poly(I:C). IRAK1-deficient human microglial cells showed higher basal levels of STAT1 and STAT2 compared with control cells. Blocking the kinase activity of TBK1/IKKε in IRAK1 knockdown human microglial cells reduced the high basal levels of STAT1/2, uncovering a TBK1/IKKε kinase-dependent mechanism controlling basal levels of STAT1/2. Stimulating IRAK1 knockdown human microglial cells with IFN-ß led to increased IL-27p28 expression compared with control cells. In IRAK1-deficient murine macrophages, increased IL-27 levels were detected by ELISA following IFN-ß stimulation compared with control macrophages together with increased nuclear levels of p-STAT1, IRF1, and IRF9. Treatment of wild-type and IRAK1-deficient murine macrophages with fludarabine similarly reduced TLR3/4-induced IL-27 cytokine levels. To our knowledge, this work represents the first report placing IRAK1 in the IFNAR pathway and identifies IRAK1 as an important regulator of STAT1, controlling IL-27 production downstream of TLR3/4 and IFNAR signaling pathways.

New versus old: Implications of evolving diagnostic criteria for relapsing-remitting multiple sclerosis.

The International Panel on Diagnosis of Multiple Sclerosis (MS) recently revised the 2010 McDonald criteria and made recommendations for revision, allowing for the earliest possible, accurate diagnosis of MS. For relapsing-remitting MS, positive, unmatched cerebrospinal fluid oligoclonal bands may substitute for dissemination in time. Symptomatic lesions, including brainstem and spinal cord, may demonstrate dissemination in space or in time if enhancing (with the exception of the optic nerve). Cortical and juxtacortical lesions are equivalent. In this retrospective analysis, we applied revised criteria to 250 patients previously diagnosed with relapsing-remitting MS according to 2010 criteria and assessed for change in diagnostic times. There was a significant improvement in time to diagnosis between 2010 and 2017 groups ( p < 0.01). Median time to diagnosis according to McDonald 2010 was 7.4 months, compared with 2.3 months for McDonald 2017. Use of cerebrospinal fluid results most frequently resulted in a reduction in time to diagnosis. Symptomatic gadolinium-enhancing lesions led to earliest diagnostic times.

Machine Learning EEG to Predict Cognitive Functioning and Processing Speed Over a 2-Year Period in Multiple Sclerosis Patients and Controls.

Event-related potentials (ERPs) show promise to be objective indicators of cognitive functioning. The aim of the study was to examine if ERPs recorded during an oddball task would predict cognitive functioning and information processing speed in Multiple Sclerosis (MS) patients and controls at the individual level. Seventy-eight participants (35 MS patients, 43 healthy age-matched controls) completed visual and auditory 2- and 3-stimulus oddball tasks with 128-channel EEG, and a neuropsychological battery, at baseline (month 0) and at Months 13 and 26. ERPs from 0 to 700 ms and across the whole scalp were transformed into 1728 individual spatio-temporal datapoints per participant. A machine learning method that included penalized linear regression used the entire spatio-temporal ERP to predict composite scores of both cognitive functioning and processing speed at baseline (month 0), and months 13 and 26. The results showed ERPs during the visual oddball tasks could predict cognitive functioning and information processing speed at baseline and a year later in a sample of MS patients and healthy controls. In contrast, ERPs during auditory tasks were not predictive of cognitive performance. These objective neurophysiological indicators of cognitive functioning and processing speed, and machine learning methods that can interrogate high-dimensional data, show promise in outcome prediction.

Paraneoplastic dentate ganglionopathy: clinical and neuroimmunologic studies.

We describe the clinical and neuropathological features of two cases of cerebellar degeneration with selective involvement of the dentate nucleus. Both cases were associated with malignancy, however known paraneoplastic antibodies were absent. Pathological studies at autopsy confirmed T-cell-mediated neuronal destruction in the cerebellum which was strikingly limited to the dentate nucleus in both patients. The occurrence of these pathological features has not been previously described in antibodynegative paraneoplastic disease, but bears similarities to Rasmussen’s encephalitis.

Premorbid cognitive functioning influences differences between self-reported cognitive difficulties and cognitive assessment in multiple sclerosis.

Cognitive difficulties are reported in up to 60% of people with MS (pwMS). There is often a discrepancy between self-reported cognitive difficulties and performance on cognitive assessments. Some of this discrepancy can be explained by depression and fatigue. Pre-MS cognitive abilities may be another important variable in explaining differences between self-reported and assessed cognitive abilities. PwMS with high estimated premorbid cognitive functioning (ePCF) may notice cognitive difficulties in daily life whilst performing within the average range on cognitive assessments. We hypothesised that, taking into account depression and fatigue, ePCF would predict (1) differences between self-reported and assessed cognitive abilities and (2) performance on cognitive assessments. We explored whether ePCF predicted (3) self-reported cognitive difficulties. Eighty-seven pwMS completed the Test of Premorbid Functioning (TOPF), the Brief International Cognitive Assessment for MS (BICAMS), self-report measures of cognitive difficulty (MS Neuropsychological Questionnaire; MSNQ), fatigue (MS Fatigue Impact Scale; MFIS) and depression (Hospital Anxiety and Depression Scale; HADS). Results revealed that, taking into account covariates, ePCF predicted (1) differences between self-reported and assessed cognitive abilities, p < .001 (model explained 29.35% of variance), and (2) performance on cognitive assessments, p < .001 (model explained 46.00% of variance), but not (3) self-reported cognitive difficulties, p = .545 (model explained 35.10% of variance). These results provide new and unique insights into predictors of the frequently observed discrepancy between self-reported and assessed cognitive abilities for pwMS. These findings have important implications for clinical practice, including the importance of exploring premorbid factors in self-reported experience of cognitive difficulties.

Neuropsychological outcomes following HSCT in MS: A systematic review.

BACKGROUND: Autologous haematopoietic stem cell transplant (HSCT) is considered an effective treatment for highly active multiple sclerosis (MS). To date, most research has focused primarily on disease outcome measures, despite the significant impact of neuropsychological symptoms on MS patients' quality of life. The current systematic review aimed to examine whether HSCT for MS impacts neuropsychological outcome measures such as cognition, fatigue, mood, and quality of life. METHODS: The review was registered with the International Prospective Register of Systematic Reviews (PROSPERO, ID: CRD42023474214). Systematic searches were carried out in six databases (PsycINFO, PubMed, Embase, Scopus, CINAHL and Web of Science) based on the following inclusion criteria: (i) published in peer-reviewed journals in English; (ii) longitudinal studies of adults with MS (iii) at least one neuropsychological outcome was assessed pre- and post-HSCT using standardised measures. Risk of bias was assessed using the National Heart, Lung and Blood Institute (NHLBI) quality assessment tools. A narrative synthesis was used to present results. RESULTS: Eleven studies were included in the review. Long-term improvements in quality of life post-HSCT were identified. In terms of cognition and fatigue, the evidence was mixed, with some post-HSCT improvements identified. Decline in cognitive performance in the short-term post-HSCT was observed. No changes in mood were identified post-HSCT. Arguments for interpreting these results with caution are presented based on risk of bias. Arguments for interpreting these results with caution are presented based on risk of bias. Limitations of the evidence are discussed, such confounding variables and lack of statistical power. CONCLUSION: The evidence base for the impact of HSCT for MS on neuropsychological outcomes is limited. Further research is required to progress understanding to facilitate clinician and patient understanding of HSCT treatment for MS.

Neuropsychology intervention for managing invisible symptoms of MS (NIMIS-MS) group: A pilot effectiveness and acceptability study.

BACKGROUND: People with MS (pwMS) commonly experience a range of hidden symptoms, including cognitive impairment, anxiety and depression, fatigue, pain, and sensory difficulties. These "invisible" symptoms can significantly impact wellbeing, relationships, employment and life goals. We developed a novel bespoke online group neuropsychological intervention combining psychoeducation and cognitive rehabilitation with an Acceptance and Commitment Therapy (ACT)-informed approach for pwMS in an acute tertiary hospital. This 'Neuropsychological Intervention for Managing Invisible Symptoms' in MS (NIMIS-MS) consisted of 6 sessions, each with a psychoeducation and ACT component. The content included psychoeducation around managing cognitive difficulties, fatigue, pain, sleep and other unpleasant sensations in MS with the general approach of understanding, monitoring, and recognising patterns and potential triggers. Specific cognitive rehabilitation and fatigue management strategies were introduced. The ACT-informed component focussed on three core ACT areas of the 'Triflex' of psychological flexibility (Harris, 2019): Being Present, Opening Up, and Doing What Matters. METHODS: 118 pwMS attended the NIMIS-MS group intervention which was delivered 14 times in six-week blocks over an 18-month period. To evaluate the effectiveness and acceptability, participants completed measures of depression and anxiety (HADS), functional impairment (WSAS), Values- Progress (VQ) and Values- Obstruction (VQ), and Acceptance of MS (MSAS) pre and post NIMIs-MS group intervention. Qualitative feedback was obtained during focus groups after the final session and via online feedback questionnaires RESULTS: Pre-post analysis showed that symptoms of depression and anxiety were significantly lower and acceptance of MS was significantly higher following completion of the NIMIS-MS group. Qualitative feedback showed that participants reported that they felt more equipped to manage the "invisible" symptoms of MS following completion of the group, and benefited from using ACT-based strategies and techniques. Participants highly valued the peer support that evolved during the NIMIS-MS groups. The online format was considered more accessible than in-person groups, due to less concerns of travel time, cost, fatigue, and comfort and infection. CONCLUSION: Evaluation suggests that our novel NIMIS-MS groups is an acceptable, beneficial and feasible approach for providing neuropsychological interventions to individuals with MS.

Relating health-related Quality of Life to disability progression in multiple sclerosis, using the 5-level EQ-5D.

BACKGROUND: Increasing use of the Quality-Adjusted Life-Year to inform resource allocation decision-making has highlighted the importance of relating clinical and health-related quality of life (HRQoL) outcomes in multiple sclerosis (MS) patients. OBJECTIVE AND METHODS: To investigate the relationship between the Expanded Disability Status Scale (EDSS) and HRQoL utility, using the 5-level EQ-5D (EQ-5D-5L). The discriminatory power of the EQ-5D-5L was assessed using Shannon's indices. RESULTS: A linear decline in utility was observed with changes in EDSS score from 0 to 6, after which point the relationship exhibited greater variability. Mean utility values ranged from -0.22 at EDSS 9 to 0.88 at EDSS 0. We found that the discriminative capacity of the EQ-5D-5L was considerably lower for the domains self-care and anxiety/depression, compared with other health-related domains. CONCLUSION: In its first reported use in an MS population, the EQ-5D-5L displayed good discriminatory capacity, although performance differed between the various domains of health, with evidence of a ceiling effect present in the domains of self-care and anxiety/depression. The EQ-5D-5L demonstrated a high correlation with EDSS in our MS cohort up to EDSS 6, after which point the utility valuation of severe health states exhibited much greater variability. Utility estimates from this study may be used in economic evaluations of disease-modifying therapies in MS, to inform resource-allocation decisions.

Symptom overlap in anxiety and multiple sclerosis.

BACKGROUND: The validity of self-rated anxiety inventories in people with multiple sclerosis (pwMS) is unclear. However, the appropriateness of self-reported depression scales has been widely examined. Given somatic symptom overlap between depression and MS, research emphasises caution when using such scales. OBJECTIVE: This study evaluates symptom overlap between anxiety and MS in a group of 33 individuals with MS, using the Beck Anxiety Inventory (BAI). METHODS: Participants underwent a neurological examination and completed the BAI. RESULTS: A novel procedure using hierarchical cluster analysis revealed three distinct symptom clusters. Cluster one ('wobbliness' and 'unsteady') grouped separately from all other BAI items. These symptoms are well-recognised MS-related symptoms and we question whether their endorsement in pwMS can be considered to reflect anxiety. A modified 19-item BAI (mBAI) was created which excludes cluster one items. This removal reduced the number of MS participants considered 'anxious' by 21.21% (low threshold) and altered the level of anxiety severity for a further 27.27%. CONCLUSION: Based on these data, it is suggested that, as with depression measures, researchers and clinicians should exercise caution when using brief screening measures for anxiety in pwMS.

Word finding, prosody and social cognition in multiple sclerosis.

BACKGROUND: Impairments in speech and social cognition have been reported in people with multiple sclerosis (pwMS), although their relationships with neuropsychological outcomes and their clinical utility in MS are unclear. OBJECTIVES: To evaluate word finding, prosody and social cognition in pwMS relative to healthy controls (HC). METHODS: We recruited people with relapsing MS (RMS, n = 21), progressive MS (PMS, n = 24) and HC (n = 25) from an outpatient MS clinic. Participants completed a battery of word-finding, social cognitive, neuropsychological and clinical assessments and performed a speech task for prosodic analysis. RESULTS: Of 45 pwMS, mean (SD) age was 49.4 (9.4) years, and median (range) Expanded Disability Severity Scale score was 3.5 (1.0-6.5). Compared with HC, pwMS were older and had slower information processing speed (measured with the Symbol Digit Modalities Test, SDMT) and higher depression scores. Most speech and social cognitive measures were associated with information processing speed but not with depression. Unlike speech, social cognition consistently correlated with intelligence and memory. Visual naming test mean response time (VNT-MRT) demonstrated worse outcomes in MS versus HC (p = .034, Nagelkerke's R2  = 65.0%), and in PMS versus RMS (p = .009, Nagelkerke's R2  = 50.2%). Rapid automatised object naming demonstrated worse outcomes in MS versus HC (p = .014, Nagelkerke's R2  = 49.1%). These word-finding measures showed larger effect sizes than that of the SDMT (MS vs. HC, p = .010, Nagelkerke's R2  = 40.6%; PMS vs. RMS, p = .023, Nagelkerke's R2  = 43.5%). Prosody and social cognition did not differ between MS and HC. CONCLUSIONS: Word finding, prosody and social cognition in MS are associated with information processing speed and largely independent of mood. Impairment in visual object meaning perception is potentially a unique MS disease-related deficit that could be further explored and cautiously considered as an adjunct disability metric for MS.

Using atypical symptoms and red flags to identify non-demyelinating disease.

BACKGROUND: Red flags and atypical symptoms have been described as being useful in suggesting alternative diagnoses to multiple sclerosis (MS) and clinically isolated syndrome (CIS); however, their diagnostic utility has not been assessed. The aim of this study was to establish the predictive value of red flags and the typicality/atypicality of symptoms at presentation in relation to the final diagnosis of patients referred with suspected MS. METHODS: All patients referred with suspected MS over a 3-year period were assessed by the typicality of the clinical presentation and the occurrence of red flags in relation to the eventual diagnosis. The extent of agreement of trainee and consultant neurologists as to typicality of clinical presentations was determined. RESULTS: Of 244 patients referred, 119 (49%) had MS/CIS and 125 (51%) did not. 41 patients were referred because of an abnormal MRI. Of 203 with clinical symptoms, 96 patients had atypical symptoms of whom, 81 (84%) did not have MS and 15 (16%) had MS/CIS. Typical symptoms occurred in 107 patients; 10% did not have MS/CIS. Atypical symptoms had a sensitivity of 84%, specificity of 90% and positive likelihood ratio (PLR) of 8.4, whereas red flags had a sensitivity of 47%, specificity of 88% and PLR of 3.9 for the exclusion of MS/CIS. Mean percentage agreement between consultants and trainees was 73% with a range of 32-96%. CONCLUSIONS: Atypical features at presentation are more sensitive, specific and have a higher PLR than red flags to refute a diagnosis of MS/CIS.

A pilot study of the immunological effects of high-dose vitamin D in healthy volunteers.

Although vitamin D deficiency is considered an environmental factor in multiple sclerosis (MS), the immunological and clinical effects of vitamin D supplementation remain unclear. We performed a pilot study of the immunomodulatory effects of vitamin D in healthy individuals (n=4), who took 5000-10,000 IU/day of vitamin D over 15 weeks. After 15 weeks of vitamin D supplementation, serum 25(OH) vitamin D levels rose significantly from baseline, with a corresponding increase in IL-10 production by peripheral blood mononuclear cells and a reduced frequency of Th17 cells. These data provide a strong rationale for randomised trials to assess the clinical effects of vitamin D supplementation in MS.

Investigating the association of mood and fatigue with objective and subjective cognitive impairment in multiple sclerosis.

Discrepancies between subjective cognitive difficulties and objective measures of cognitive function in people with MS have been identified and may be related to mood and fatigue. The aim of the present study was to examine associations of depression and fatigue with discrepancies between subjective and objective cognitive functioning in pwMS. 177 participants with MS attending a University Hospital Department of Neurology MS Outpatient clinic completed the Brief International Cognitive Assessment for MS (BICAMS), MS Neuropsychological Questionnaire (MSNQ), Hospital Anxiety and Depression Scale (HADS) and Modified Fatigue Impact Scale (MFIS). To quantify the discrepancy between objective (BICAMS) and subjective (MSNQ) cognitive functioning, discrepancy scores were calculated by subtracting MSNQ z-score from composite BICAMS z-score. Based on their discrepancy score, participants were grouped as 'Underestimated', 'Overestimated' and 'Non-discrepant'. 39% of the total sample demonstrated poorer subjective cognitive functioning than their objective cognitive performance suggested ('Underestimated'). 23% of the total sample indicated lower objective scores than their subjective report suggests ('Overestimated'). 38% participants indicated relatively no discrepancy between objective and subjective cognitive measures ('Non-discrepant'). Significant differences were observed between the discrepancy groups in terms of depression and fatigue, with the 'Underestimated' group demonstrating greater levels of depression and fatigue (ps < .01). Regression analysis indicated that cognitive fatigue and depression significantly contributed to variance in subjective cognitive functioning. Our findings suggest that subjective reports of cognitive function may be influenced by depression and fatigue, emphasising the importance of cognitive, mood and fatigue screening as part of routine clinical care.

Interpreting the clinical importance of the relationship between subjective fatigue and cognitive impairment in multiple sclerosis (MS): How BICAMS performance is affected by MS-related fatigue.

BACKGROUND: There is evidence that subjective fatigue can influence cognitive functioning in multiple sclerosis (MS). DeLuca et al.'s (2004) Relative Consequence Model proposes that impairments to other high-level cognitive functions, such as memory, result from the disease's effect on information processing speed. OBJECTIVE: The primary aims of the study were to investigate both 1) the relationship between subjective fatigue and cognitive functioning, as measured by the widely used Brief International Cognitive Assessment for Multiple Sclerosis (BICAMS) in MS; and 2) the consequential effect of fatigue on information processing speed as predicted by the Relative Consequence Model. METHODS: 192 participants with MS attending tertiary referral MS centre completed the Modified Fatigue Impact Scale and BICAMS. RESULTS: Multiple correlation analyses determined that there were statistically significant relationships between all domains assessed by the BICAMS and levels of fatigue, such that higher levels of self-reported fatigue were associated with lower performance on information-processing, and visual and verbal learning. After controlling for information processing speed, the strength of correlation between fatigue and learning performance weakened. Linear regression analysis showed that fatigue predicted the most variance in verbal learning and 11.7% of the overall variance in BICAMS performance. CONCLUSION: Subjective fatigue and objective cognitive performance in MS are related. Caution is advised in the interpretation of BICAMS scores in cases where high levels of fatigue are present, and more detailed neuropsychological assessments may be required in order to accurately identify objective cognitive impairment independent of subjective fatigue.

Association between speech rate measures and cognitive function in people with relapsing and progressive multiple sclerosis.

Background: Cognitive impairments are well-documented in multiple sclerosis (MS), while speech impairments are often overlooked despite their significant effect on quality of life. For effective clinical management of multisystem conditions such as MS, consideration should be given to the interaction between deficits in multiple domains, such as speech and cognition. To evaluate speech rate measures of spontaneous and read speech, in people with MS and to examine the link between speech and cognition. Methods: Forty-five people with MS and 25 controls underwent an extensive cognitive battery, including executive functioning, information processing and memory tasks, and completed two speech tasks: a reading task and a picture description task, from which speech rate measures were derived. Results: The progressive MS cohort had reduced articulation (p < 0.04) and speech rate (p < 0.02) compared to controls and those with relapsing MS. Regression models also revealed information processing speed accounted for 18% to 30% of the variance of spontaneous speech rate measures, and 27% of read speech. Executive functioning accounted for a further 10% of the variance of speech rate in those with MS. Conclusions: The present study suggests that speech production is contingent on cognitive ability, with information processing speed and executive functioning linked with speech timing patterns.

IL-27 mediates the response to IFN-ß therapy in multiple sclerosis patients by inhibiting Th17 cells.

Interferon (IFN)-ß is a commonly used therapy for relapsing remitting multiple sclerosis (RRMS). However its protective mechanism is still unclear and the failure of many patients to respond has not been explained. We have found that IFN-ß suppressed IL-23 and IL-1ß production and increased IL-10 production by human dendritic cells (DC) activated with the TLR2 and dectin-1 agonist zymosan. Furthermore, IFN-ß impaired the ability of DC to promote IL-17 production by CD4(+) T cells, but did not affect IFN-γ production. IFN-ß induced IL-27 expression by DC, and neutralisation of IL-27 abrogated the suppressive effects of IFN-ß on zymosan-induced IL-1 and IL-23 production and the generation of Th17 cells in vitro. Complementary in vivo studies in a mouse model showed that treatment with IFN-ß enhanced expression of IL-27, and reduced IL-17 in the CNS and periphery and attenuated the clinical signs of experimental autoimmune encephalomyelitis (EAE). In addition, the significant suppressive effect of IFN-ß on the ability of DC to promote Th17 cells was lost in cells from IL-27 receptor deficient mice. Finally, we showed that PBMC from non-responder RRMS patients produced significantly less IL-27 in response to IFN-ß than patients who responded to IFN-ß therapy. Our findings suggest that IFN-ß mediates its therapeutic effects in MS at least in part via the induction of IL-27, and that IL-27 may represent an alternative therapy for MS patients that do not respond to IFN-ß.

CD39+Foxp3+ regulatory T Cells suppress pathogenic Th17 cells and are impaired in multiple sclerosis.

Despite the fact that CD4(+)CD25(+)Foxp3(+) regulatory T cells (Treg cells) play a central role in maintaining self-tolerance and that IL-17-producing CD4(+) T cells (Th17 cells) are pathogenic in many autoimmune diseases, evidence to date has indicated that Th17 cells are resistant to suppression by human Foxp3(+) Treg cells. It was recently demonstrated that CD39, an ectonucleotidase which hydrolyzes ATP, is expressed on a subset of human natural Treg cells. We found that although both CD4(+)CD25(high)CD39(+) and CD4(+)CD25(high)CD39(-) T cells suppressed proliferation and IFN-gamma production by responder T cells, only the CD4(+)CD25(high)CD39(+), which were predominantly FoxP3(+), suppressed IL-17 production, whereas CD4(+)CD25(high)CD39(-) T cells produced IL-17. An examination of T cells from multiple sclerosis patients revealed a normal frequency of CD4(+)CD25(+)CD127(low)FoxP3(+), but interestingly a deficit in the relative frequency and the suppressive function of CD4(+)CD25(+)CD127(low)FoxP3(+)CD39(+) Treg cells. The mechanism of suppression by CD39(+) Treg cells appears to require cell contact and can be duplicated by adenosine, which is produced from ATP by the ectonucleotidases CD39 and CD73. Our findings suggest that CD4(+)CD25(+)Foxp3(+)CD39(+) Treg cells play an important role in constraining pathogenic Th17 cells and their reduction in multiple sclerosis patients might lead to an inability to control IL-17 mediated autoimmune inflammation.