Expansion of regulatory T cells via IL-2/anti-IL-2 mAb complexes suppresses experimental myasthenia.

Human autoimmune diseases are often characterized by a relative deficiency in CD4(+)CD25(+) regulatory T cells (Treg). We therefore hypothesized that expansion of Treg can ameliorate autoimmune pathology. We tested this hypothesis in an experimental model for autoimmune myasthenia gravis (MG), a B-cell-mediated disease characterized by auto-Ab directed against the acetylcholine receptor within neuromuscular junctions. We showed that injection of immune complexes composed of the cytokine IL-2 and anti-IL-2 mAb (JES6-1A12) induced an effective and sustained expansion of Treg, via peripheral proliferation of CD4(+)CD25(+)Foxp3(+) cells and peripheral conversion of CD4(+)CD25(-)Foxp3(-) cells. The expanded Treg potently suppressed autoreactive T- and B-cell responses to acetylcholine receptor and attenuated the muscular weakness that is characteristic of MG. Thus, IL-2/anti-IL-2 mAb complexes can expand functional Treg in vivo, providing a potential clinical application of this modality for treatment of MG and other autoimmune disorders.

Nicotinic attenuation of central nervous system inflammation and autoimmunity.

The expression of nicotinic acetylcholine receptors by neurons, microglia, and astrocytes suggests possibly diverse mechanisms by which natural nicotinic cholinergic signaling and exposure to nicotine could modulate immune responses within the CNS. In this study, we show that nicotine exposure significantly delays and attenuates inflammatory and autoimmune responses to myelin Ags in the mouse experimental autoimmune encephalomyelitis model. In the periphery, nicotine exposure inhibits the proliferation of autoreactive T cells and alters the cytokine profile of helper T cells. In the CNS, nicotine exposure selectively reduces numbers of CD11c(+) dendritic and CD11b(+) infiltrating monocytes and resident microglial cells and down-regulates the expression of MHC class II, CD80, and CD86 molecules on these cells. The results underscore roles of nicotinic acetylcholine receptors and nicotinic cholinergic signaling in inflammatory and immune responses and suggest novel therapeutic options for the treatment of inflammatory and autoimmune disorders, including those that affect the CNS.

APOE ε4 is associated with exacerbation of cognitive decline in patients with multiple sclerosis.

BACKGROUND: : In previous studies we and others have demonstrated an association with apolipoprotein (APOE) ε4 genotype and the presence of cognitive deficits in multiple sclerosis (MS). In this follow-up study, we have assessed whether APOE ε4 status exacerbates progression of cognitive deficits in MS. METHODS: : A total of 197 patients with MS were assessed for APOE genotype, and baseline cognitive performance was measured using a standardized battery of tests. One hundred seventy patients (86.3%) were clinically followed up for 1 year and were assessed for progression of cognitive deficits. RESULTS: : The APOE ε4 allele was present in 24.7% of patients. During 1-year follow-up, significant progression of cognitive deficits was found in APOE ε4 carriers (P=0.001) after logistic regression analysis controlling for sex, ethnicity, age, education, disease duration, severity, and subtype. CONCLUSIONS: : APOE ε4 carriers with MS have worsening progression of cognitive deficits than noncarriers. APOE ε4 carrier status predicts cognitive decline in verbal learning and memory.

Natalizumab in Early Relapsing-Remitting Multiple Sclerosis: A 4-Year, Open-Label Study.

INTRODUCTION: STRIVE was a 4-year, multicenter, observational, open-label, single-arm study of natalizumab treatment in anti-JC virus antibody-negative (JCV-negative) relapsing-remitting multiple sclerosis (RRMS) patients with disease duration ≤ 3 years. The objective of STRIVE was to examine no evidence of disease activity (NEDA) status and predictors of NEDA in natalizumab-treated patients with early RRMS. METHODS: Proportions of patients with NEDA were evaluated along with baseline predictors of NEDA, annualized relapse rate, 24-week confirmed disability worsening (CDW), magnetic resonance imaging assessments (T2 and gadolinium-enhancing lesions), and serious adverse events. RESULTS: In years 1 and 2, 56.1% (95% confidence interval [CI] 48.7-63.4%) and 73.6% (95% CI 66.2-80.2%) of patients (intent-to-treat population [N = 222]), respectively, achieved NEDA. In years 3 and 4, 84.6% (95% CI 78.0-89.9%) and 91.9% (95% CI 86.4-95.8%) of patients, respectively, achieved Clinical NEDA (no relapses or 24-week CDW). Baseline predictors of NEDA in year 4 were Expanded Disability Status Scale score ≤ 2.0 (odds ratio [OR] = 3.85 [95% CI 1.54-9.63]; p = 0.004) and T2 lesion volume > 4 cc (OR = 0.39 [95% CI 0.15-0.98]; p = 0.046), with the latter also predicting Clinical NEDA in year 4 (OR = 0.21 [95% CI 0.05-0.92]; p = 0.038). The cumulative probability of CDW at year 4 was 19.3%. Serious adverse events were reported in 11.3% of patients. CONCLUSION: These results support the long-term safety and effectiveness of natalizumab. Baseline predictors of NEDA help to inform benefit-risk assessments of natalizumab treatment in JCV-negative patients with early RRMS. TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT01485003.

Improving resident research in physical medicine and rehabilitation: impact of a structured training program.

OBJECTIVE: This study describes a research training program that implemented several processes and structures with the aim of increasing the quality and quantity of resident research in physical medicine and rehabilitation. Another aim of the program was to address the Accreditation Council for Graduate Medical Education (ACGME) Practice-Based Learning and Improvement competency. DESIGN: Educational program. RESULTS: Data on resident research activity for 11 years before the implementation of the research program were compared with 4 years of data after implementation. There were statistically significant increases in both the total number of publications (P = 0.03) and the number of empirical, data-based publications after implementation of the program (P = 0.03). CONCLUSIONS: The findings from this study suggest that a structured research training program may have a salutary effect on increasing the quality and quantity of resident research.

Appropriateness of the Ilfeld Psychiatric Symptom Index as a screening tool for depressive symptomatology in persons with spinal cord injury.

BACKGROUND: Depressive symptomatology is seen in some persons with spinal cord injury (SCI). Identification of a depressed mood can assist clinicians in early treatment. The Ilfeld Psychiatric Symptom Index (Ilfeld PSI) is a screening tool that assesses a range of symptoms: depression, cognitive disturbance, anxiety, and anger. The purpose of this study was to compare the efficacy of the Ilfeld PSI to the Zung Self-Rating Depression Scale (Zung SRS) in persons with chronic SCI. DESIGN: This was a case-control study. METHODS: A total of 59 subjects completed the study: 20 persons with tetraplegia, 19 with paraplegia, and 20 age-matched able-bodied controls. The total scores for both measures were analyzed using Pearson correlation, analysis of variance, and chi-square tests. RESULTS: The Zung SRS total scores correlated with the Ilfeld PSI subscales and index scores. When using the traditional cutoff scores, there was a low level of agreement between scales. The Ilfeld PSI classified 79% of the SCI group and 75% of controls as depressed. In contrast, 8% of the SCI group and none of the controls met criteria for depression using the Zung SRS. CONCLUSIONS: The Ilfeld PSI screens for a broad range of symptoms; however, it poorly discriminates somatic symptoms unrelated to depression. Therefore, the Ilfeld PSI may not be a useful instrument for persons with SCI.

Autonomic dysreflexia: one more way EMS can positively affect patient survival.

Autonomic dysreflexia is a life-threatening medical condition that affects people with spinal cord injuries above T6. Caused by the division of the autonomic nervous system, it can result in disastrous hypertension. Although complicated in nature, AD can be quickly treated and reversed by prehospital providers. The prompt emptying of a patient's bladder and/or bowels will resolve most occurrences. Other factors that can't be resolved in the prehospital setting may cause AD. In these situations, quickly transport the patient to a definitive care facility and consider the use of antihypertensive agents. Bladder catheterization and digital bowel emptying are not everyday EMS skills. They are, however, skills within the range of EMS abilities. Providers should contact their medical directors or training supervisors to obtain the training necessary to carry out both techniques. Having these skills will arm you with the necessary abilities to mitigate an episode of autonomic dysreflexia.

B cells from glatiramer acetate-treated mice suppress experimental autoimmune encephalomyelitis.

Multiple sclerosis (MS) is an autoimmune disease of the central nervous system (CNS) thought to be primarily mediated by T cells. However, emerging evidence supports an important role for B cells in the pathogenesis and inhibition of MS. Glatiramer acetate (GA), a Food and Drug Administration-approved drug for the treatment of MS, has a good safety profile. But GA's mechanism of action in MS is still elusive. In this study, we showed that B cells from GA-treated mice increased production of IL-10 and reduced expression of co-stimulatory molecules viz.: CD80 and CD86. B cells from GA-treated mice also diminished proliferation of myelin oligodendrocyte glycoprotein (MOG(35-55)) specific T cells. Purified B cells transferred from GA-treated mice suppressed experimental autoimmune encephalomyelitis (EAE) in recipient mice compared with B cells transferred from mice treated with PBS or ovalbumin. The treatment effect of GA in EAE was abrogated in B cell-deficient mice. Transfer of B cells from GA-treated mice inhibited the proliferation of autoreactive T cells as well as the development of Th1 and Th17 cells but promoted IL-10 production in recipient mice. The number of peripheral CD11b(+) macrophages in recipient mice also decreased after transfer of B cells from GA-treated mice; however, the number of dendritic cells and regulatory T cells remained unaltered. These results suggest that B cells are important to the protective effects of GA in EAE.

Central nervous system (CNS)-resident natural killer cells suppress Th17 responses and CNS autoimmune pathology.

Natural killer (NK) cells of the innate immune system can profoundly impact the development of adaptive immune responses. Inflammatory and autoimmune responses in anatomical locations such as the central nervous system (CNS) differ substantially from those found in peripheral organs. We show in a mouse model of multiple sclerosis that NK cell enrichment results in disease amelioration, whereas selective blockade of NK cell homing to the CNS results in disease exacerbation. Importantly, the effects of NK cells on CNS pathology were dependent on the activity of CNS-resident, but not peripheral, NK cells. This activity of CNS-resident NK cells involved interactions with microglia and suppression of myelin-reactive Th17 cells. Our studies suggest an organ-specific activity of NK cells on the magnitude of CNS inflammation, providing potential new targets for therapeutic intervention.

T-bet deficiency decreases susceptibility to experimental myasthenia gravis.

T-bet, a tissue-specific transcription factor, controls T helper 1 (Th1) cell differentiation and IFN-production. Given the reciprocal relationship between Th1 and other types of helper T cells, we hypothesized that T-bet impacts multiple helper and regulatory T (Treg) cells, thereby influencing the magnitude of autoimmune disease. We tested this hypothesis in an experimental model of autoimmune myasthenia gravis (EAMG) of mice. Myasthenia gravis (MG) and EAMG are T cell-driven, IgG autoantibody-mediated disorders that destroy muscles by attacking the target antigen acetylcholine receptor (AChR) or other antigens of skeletal muscle at neuromuscular junctions. We show that, compared to wild-type mice, AChR-primed T-bet(-/-) mice are less susceptible to EAMG. This phenotype is associated with a reduction of autoreactive Th1 cells and augmentation of Th2 and Th17 cells as well as an upregulation of Foxp3 expression by T-bet(-/-)CD4(+)CD25(+) Treg cells. Thus, in our model, T-bet not only specifies the Th1 lineage but also has a broad influence on autoreactive Th2, Th17 and Treg cells. These coordinated effects reduce the genesis of pathogenic antibodies and protect against B cell-mediated EAMG.

IL-21 receptor expression determines the temporal phases of experimental autoimmune encephalomyelitis.

The IL-21 receptor (IL-21R) consists of a unique subunit and a common gamma chain (gamma(c)) that is shared with other cytokines including IL-2, IL-4, IL-7, and IL-15. The interaction between IL-21 and IL-21R results in significant effects on both innate and adaptive immune responses. In this study we examined the influence of IL-21R deficiency (IL-21R(-/-)) on the development of experimental autoimmune encephalomyelitis (EAE), an animal model of human multiple sclerosis (MS). IL-21R(-/-) mice developed EAE earlier and more severe neurological impairment than control mice, yet those mice could effectively recover from neurological deficits. The impact on EAE initiation by IL-21R deficiency was associated with a defect of CD4(+)CD25(+) T regulatory (Treg) cells and a down-regulated expression of Foxp3. The recovery from IL-21R(-/-) EAE was correlated with an expansion of Treg cells as well as an organ-specific redistribution of NK cells. These results suggest that a temporal influence of IL-21 on the activity of immunoregulatory circuits can be important in the modulation of the course of the autoimmune disease.

CCL2 recruitment of IL-6-producing CD11b+ monocytes to the draining lymph nodes during the initiation of Th17-dependent B cell-mediated autoimmunity.

The development and function of Th17 cells are influenced in part by the cytokines TGF-beta, IL-23 and IL-6, but the mechanisms that govern recruitment and activity of Th17 cells during initiation of autoimmunity remain poorly defined. We show here that the development of autoreactive Th17 cells in secondary lymphoid organs in experimental autoimmune myasthenia gravis--an animal model of human myasthenia gravis--is modulated by IL-6-producing CD11b(+) cells via the CC chemokine ligand 2 (CCL2). Notably, acetylcholine receptor (AChR)-reactive Th17 cells provide help for the B cells to produce anti-AChR antibodies, which are responsible for the impairment of the neuromuscular transmission that contributes to the clinical manifestations of autoimmunity, as indicated by a lack of disease induction in IL-17-deficient mice. Thus, Th17 cells can promote humoral autoimmunity via a novel mechanism that involves CCL2.

Therapeutic effect of anthracene-based anticancer agent ethonafide in an animal model of multiple sclerosis.

The side effects of cancer chemotherapeutic agents such as mitoxantrone (MIT) in multiple sclerosis (MS) patients justify the search for less toxic drugs. Ethonafide is an anthracene-based antineoplastic drug similar to MIT. With reference to MIT, we examined the effect of ethonafide on experimental autoimmune encephalomyelitis (EAE) in C57BL/6 mice, an animal model of human MS. We demonstrated that ethonafide is effective in preventing development of EAE as well as in ameliorating the severity of EAE when disease is ongoing. In relatively higher dosages, the effects of ethonafide and MIT on EAE were identical, whereas in lower dosages, MIT seemed more effective. Therapeutic effects of ethonafide were associated with the initial reduction in cellular counts of CD3(+), CD4(+), CD8(+), B220(+), CD11b(+), NK cells, and NKT cells, followed by recovery of these cells from the bone marrow. Interestingly, the recovered autoreactive T cells in ethonafide-treated animals have reduced capacity to expand and produce cytokines in response to myelin Ag stimulation. Furthermore, CD4(+)CD25(+) regulatory T cells were relatively resistant to depletion and/or recovered faster than T effector cells. The ability of regulatory T cells to resist depletion and replenish quickly during cell ablation therapy may provide an opportunity to reprogram the immune system. Moreover, we provided evidences that ethonafide has less cardiac toxicity compared with MIT. The effectiveness and the low cardiotoxicity of ethonafide might make it a promising immunosuppressive agent for clinical use in treating MS patients.

Do Th2 cells mediate the effects of glatiramer acetate in experimental autoimmune encephalomyelitis?

Mechanisms underlying the clinical benefits of glatiramer acetate (GA) for patients with multiple sclerosis (MS) remain elusive. A prevailing hypothesis is that GA can induce Th2-polarized T cells, which cross-recognize myelin-specific epitopes and can inhibit myelin-reactive autoaggression in Th1 T cells, a process referred to as 'bystander suppression.' To test whether the efficacy of GA is indeed mediated by Th2 T cells, we have utilized an animal model for MS: experimental autoimmune encephalomyelitis (EAE) in C57BL/6 mice. GA therapy conferred moderate protection from EAE. GA-reactive T cells from these mice were not Th2 polarized, and the Th1 cytokine reduction of myelin-reactive T cells in GA-treated mice was comparable to that in untreated control mice. Significantly, the protective effects of GA against EAE were also observed in IL-4-, IL-10-deficient and IL-4/IL-10 double-deficient mice. Similar to wild-type mice, GA therapy in IL-4- and IL-10-deficient mice was associated with diminished myelin-reactive T cell expansion and reduced production of myelin antigen-induced IFN-gamma and tumor necrosis factor-alpha. Thus, despite the absence of two prominent Th2 cytokines, IL-4 and IL-10, either alone or combined, GA was still beneficial in suppressing EAE. Our results caution against the notion that Th2 cells and bystander suppression account for the effect of GA on EAE and suggest that an alternative mechanism may operate in GA-treated MS patients.

Autoreactive T cells mediate NK cell degeneration in autoimmune disease.

Emerging evidence indicates that NK cells play an important and complex role in autoimmune disease. Humans with autoimmune diseases often have reduced NK cell numbers and compromised NK cell functions. Mechanisms underlying this NK cell degeneration and its biological significance are not known. In this study we show that, in an experimental model of human autoimmune myasthenia gravis induced by a self-Ag, the acetylcholine receptor, NK cells undergo proliferation during the initiation of autoimmunity, followed by significant degeneration associated with the establishment of the autoreactive T cell response. We show that NK cell degeneration was mediated by IL-21 derived from autoreactive CD4(+) T cells, and that acetylcholine receptor-immunized IL-21R-deficient mice, with competent NK cells, developed exacerbated autoimmunity. Thus, NK cell degeneration may serve as a means evolved by the immune system to control excessive autoimmunity.

Cooperation of invariant NKT cells and CD4+CD25+ T regulatory cells in the prevention of autoimmune myasthenia.

CD1d-restricted NKT cells and CD4+CD25+ regulatory T (Treg) cells are thymus-derived subsets of regulatory T cells that have an important role in the maintenance of self-tolerance. Whether NKT cells and Treg cells cooperate functionally in the regulation of autoimmunity is not known. We have explored this possibility in experimental autoimmune myasthenia gravis (EAMG), an animal model of human myasthenia gravis, induced by immunization of C57BL/6 mice with the autoantigen acetylcholine receptor. We have demonstrated that activation of NKT cells by a synthetic glycolipid agonist of NKT cells, alpha-galactosylceramide (alpha-GalCer), inhibits the development of EAMG. alpha-GalCer administration in EAMG mice increased the size of the Treg cell compartment, and augmented the expression of foxp3 and the potency of CD4+CD25+ cells to inhibit proliferation of autoreactive T cells. Furthermore, alpha-GalCer promoted NKT cells to transcribe the IL-2 gene and produce IL-2 protein. Depletion of CD25+ cells or neutralization of IL-2 reduced the therapeutic effect of alpha-GalCer in this model. Thus, alpha-GalCer-activated NKT cells can induce expansion of CD4+CD25+ Treg cells, which in turn mediate the therapeutic effects of alpha-GalCer in EAMG. Induced cooperation of NKT cells and Treg cells may serve as a superior strategy to treat autoimmune disease.

Spinal cord injury computer-assisted instruction for medical students.

OBJECTIVE: To determine if a computer-assisted instruction program would improve fourth-year medical students' knowledge base related to spinal cord injury, as determined by pretest and posttest scores. DESIGN: A multimedia computer-assisted instruction program was developed and offered on a volunteer basis to an entire class of fourth-year medical students (n = 168). Effectiveness of the instructional content was evaluated with pretests and posttests, and overall user satisfaction with the module was assessed with the courseware evaluation. RESULTS: The responses yielded 83 sets of completed pretest and posttest pairs and 80 sets of fully completed courseware evaluations. Mean posttest score was significantly higher than the mean pretest score (pretest, 6.65 +/- 1.44, vs. posttest, 7.36 +/- 1.38; df = 82, t = -4.74, P < 0.001). Courseware evaluations yielded positive ratings in all areas, including applicability and usability. CONCLUSIONS: The significantly increased posttest scores suggest that the students left the program with an expanded knowledge base in the content areas of spinal cord injury medicine covered in the computer-assisted instruction program.

Critical review of prolotherapy for osteoarthritis, low back pain, and other musculoskeletal conditions: a physiatric perspective.

The current scientific literature relevant to the use of prolotherapy for osteoarthritis, low back pain, and other musculoskeletal conditions was reviewed and critically analyzed to determine a clinical effect. Three randomized, controlled studies were found studying the use of dextrose/glycerine/phenol prolotherapy for chronic low back pain; however, they were inconclusive due to the lack of adequate controls, heterogeneity in patient diagnoses, and variations in solutions injected. Two randomized, controlled studies were found that provide some evidence supporting the use of 10% dextrose prolotherapy for osteoarthritis. The sample size of the study (n = 13) involving osteoarthritic thumbs and fingers may have been too small to be strongly conclusive; however, it provides preliminary data to support future studies. Two studies involving osteoarthritic knees report an improvement in anterior cruciate ligament laxity; however, they did not have control groups for comparison. Only case reports were found supporting the pursuit of controlled clinical studies of prolotherapy for chronic neck pain. On the basis of the scarce body of literature critically reviewed to date, the clinical efficacy of prolotherapy in treating osteoarthritis, low back pain, and other musculoskeletal conditions remains inconclusive.