Uwe K. Zettl

Cerebrospinal fluid findings in aquaporin-4 antibody positive neuromyelitis optica: results from 211 lumbar punctures.

BACKGROUND Neuromyelitis optica (NMO, Devic disease) is a severely disabling autoimmune disorder of the CNS, which was considered a subtype of multiple sclerosis (MS) for many decades. Recently, however, highly specific serum autoantibodies (termed NMO-IgG or AQP4-Ab) have been discovered in a subset (60-80%) of patients with NMO. These antibodies were subsequently shown to be directly involved in the pathogenesis of the condition. AQP4-Ab positive NMO is now considered an immunopathogenetically distinct disease in its own right. However, to date little is known about the cerebrospinal fluid (CSF) in AQP4-Ab positive NMO. OBJECTIVE To describe systematically the CSF profile of AQP4-Ab positive patients with NMO or its formes frustes, longitudinally extensive myelitis and optic neuritis. MATERIAL AND METHODS Cytological and protein biochemical results from 211 lumbar punctures in 89 AQP4-Ab positive patients of mostly Caucasian origin with neuromyelitis optica spectrum disorders (NMOSD) were analysed retrospectively. RESULTS CSF-restricted oligoclonal IgG bands, a hallmark of MS, were absent in most patients. If present, intrathecal IgG (and, more rarely, IgM) synthesis was low, transient, and, importantly, restricted to acute relapses. CSF pleocytosis was present in around 50% of samples, was mainly mild (median, 19 cells/μl; range 6-380), and frequently included neutrophils, eosinophils, activated lymphocytes, and/or plasma cells. Albumin CSF/serum ratios, total protein and CSF L-lactate levels correlated significantly with disease activity as well as with the length of the spinal cord lesions in patients with acute myelitis. CSF findings differed significantly between patients with acute myelitis and patients with acute optic neuritis at the time of LP. Pleocytosis and blood CSF barrier dysfunction were also present during remission in some patients, possibly indicating sustained subclinical disease activity. CONCLUSION AQP4-Ab positive NMOSD is characterized by CSF features that are distinct from those in MS. Our findings are important for the differential diagnosis of MS and NMOSD and add to our understanding of the immunopathogenesis of this devastating condition.

Animal models of multiple sclerosis—Potentials and limitations

Abstract Experimental autoimmune encephalomyelitis (EAE) is still the most widely accepted animal model of multiple sclerosis (MS). Different types of EAE have been developed in order to investigate pathogenetic, clinical and therapeutic aspects of the heterogenic human disease. Generally, investigations in EAE are more suitable for the analysis of immunogenetic elements (major histocompatibility complex restriction and candidate risk genes) and for the study of histopathological features (inflammation, demyelination and degeneration) of the disease than for screening of new treatments. Recent studies in new EAE models, especially in transgenic ones, have in connection with new analytical techniques such as microarray assays provided a deeper insight into the pathogenic cellular and molecular mechanisms of EAE and potentially of MS. For example, it was possible to better delineate the role of soluble pro-inflammatory (tumor necrosis factor-α, interferon-γ and interleukins 1, 12 and 23), anti-inflammatory (transforming growth factor-β and interleukins 4, 10, 27 and 35) and neurotrophic factors (ciliary neurotrophic factor and brain-derived neurotrophic factor). Also, the regulatory and effector functions of distinct immune cell subpopulations such as CD4+ Th1, Th2, Th3 and Th17 cells, CD4+FoxP3+ Treg cells, CD8+ Tc1 and Tc2, B cells and γδ+ T cells have been disclosed in more detail. The new insights may help to identify novel targets for the treatment of MS. However, translation of the experimental results into the clinical practice requires prudence and great caution.

Safety and clinical outcomes of rituximab therapy in patients with different autoimmune diseases: experience from a national registry (GRAID)

IntroductionEvidence from a number of open-label, uncontrolled studies has suggested that rituximab may benefit patients with autoimmune diseases who are refractory to standard-of-care. The objective of this study was to evaluate the safety and clinical outcomes of rituximab in several standard-of-care-refractory autoimmune diseases (within rheumatology, nephrology, dermatology and neurology) other than rheumatoid arthritis or non-Hodgkins lymphoma in a real-life clinical setting.MethodsPatients who received rituximab having shown an inadequate response to standard-of-care had their safety and clinical outcomes data retrospectively analysed as part of the German Registry of Autoimmune Diseases. The main outcome measures were safety and clinical response, as judged at the discretion of the investigators.ResultsA total of 370 patients (299 patient-years) with various autoimmune diseases (23.0% with systemic lupus erythematosus, 15.7% antineutrophil cytoplasmic antibody-associated granulomatous vasculitides, 15.1% multiple sclerosis and 10.0% pemphigus) from 42 centres received a mean dose of 2,440 mg of rituximab over a median (range) of 194 (180 to 1,407) days. The overall rate of serious infections was 5.3 per 100 patient-years during rituximab therapy. Opportunistic infections were infrequent across the whole study population, and mostly occurred in patients with systemic lupus erythematosus. There were 11 deaths (3.0% of patients) after rituximab treatment (mean 11.6 months after first infusion, range 0.8 to 31.3 months), with most of the deaths caused by infections. Overall (n = 293), 13.3% of patients showed no response, 45.1% showed a partial response and 41.6% showed a complete response. Responses were also reflected by reduced use of glucocorticoids and various immunosuppressives during rituximab therapy and follow-up compared with before rituximab. Rituximab generally had a positive effect on patient well-being (physicians visual analogue scale; mean improvement from baseline of 12.1 mm).ConclusionsData from this registry indicate that rituximab is a commonly employed, well-tolerated therapy with potential beneficial effects in standard of care-refractory autoimmune diseases, and support the results from other open-label, uncontrolled studies.

Macrophages in Multiple Sclerosis

Macrophages are important effector cells involved in the pathogenesis of demyelination in multiple sclerosis (MS). Macrophage differentiation was studied in a series of 158 MS plaques from 43 patients obtained at different stages of the disease. Macrophages were identified by immunocytochemistry using a panel of antibodies recognizing different formalin- and paraffin-resistant macrophage activation antigens. The number of cells stained with each antibody was related to the demyelinating activity of the lesions as detected by the presence of myelin degradation products as well as to the category of MS tissue. Highest numbers of macrophages were observed in actively demyelinating and early remyelinating lesions using immunocytochemistry for the panmacrophage marker Ki-M1P. Lower numbers were encountered in inactive, demyelinated or late remyelinated lesions. The acute stage inflammatory macrophage markers MRP14 and 27E10 were selectively expressed in early and late active lesions, thus allowing the identification of actively demyelinating lesions. The chronic stage inflammatory macrophage marker 25F9, in contrast, showed a continuous expression also in inactive lesions. The different types of MS tissue revealed significant differences in their macrophage response. The most intense macrophage infiltration was seen in acute MS cases whereas lesions of early and late chronic MS showed lower macrophage levels. These findings indicate a differentiated pattern of macrophage activation in MS depending on the stage of the demyelinating activity as well as on the category of MS tissue. Furthermore, these macrophage markers give new parameters for staging the inflammatory and demyelinating activity of MS lesions.

Cerebrospinal fluid biomarkers in multiple sclerosis

In patients with multiple sclerosis (MS) intensive efforts are directed at identifying biomarkers in bodily fluids related to underlying disease mechanisms, disease activity and progression, and therapeutic response. Besides MR imaging parameters cerebrospinal fluid (CSF) biomarkers provide important and specific information since changes in the CSF composition may reflect disease mechanisms inherent to MS. The different cellular and protein-analytical methods of the CSF and the recommended standard of the diagnostic CSF profile in MS are described. A brief update on possible CSF biomarkers that might reflect key pathological processes of MS such as inflammation, demyelination, neuroaxonal loss, gliosis and regeneration is provided.

Animal models of multiple sclerosis for the development and validation of novel therapies – potential and limitations

Various types of experimental autoimmune encephalomyelitis (EAE) reflect some of the pathogenetic, clinical, and therapeutic features of the different forms of multiple sclerosis (MS), thereby, providing some, albeit limited, insight into the molecular and cellular basis of the human disease. Specific questions of MS therapy including the search for new therapeutic targets and strategies and their validation require investigations in different available EAE models. A survey is given of experimental therapeutic approaches that are currently under study with the most promising examples of monoclonal antibodies, gene therapy, stem cell transplantation and orally applied small molecular weight disease-modifying drugs. Reasons for therapy failure and adverse side-effects of some experimental trials are discussed. Precaution is advised, if results of new experimental approaches are translated into clinical practice.

Longitudinal extensive transverse myelitis—it's not all neuromyelitis optica

Longitudinal extensive transverse myelitis (LETM) is defined as a spinal cord lesion that extends over three or more vertebrae, as seen on MRI of the spine. The clinical presentation of a patient with LETM is often dramatic and can consist of paraparesis or tetraparesis, sensory disturbances, and gait, bladder, bowel and/or sexual dysfunction. LETM is a characteristic feature of neuromyelitis optica, but such spinal lesions can also occur in various other autoimmune and inflammatory diseases that involve the CNS—such as multiple sclerosis, sarcoidosis or Sjögren syndrome—or in infectious diseases with CNS involvement. Patients with a neoplastic disorder or traumatic spinal cord injury can also present with longitudinal spinal lesions. In this Review, the signs and symptoms that suggest various etiologies and differential diagnoses of LETM are described, and illustrated by educational case studies. The best therapeutic options for patients with each diagnosis are also discussed.

Costs and quality of life in multiple sclerosis

We performed a cross-sectional, “bottom-up” observational study of resource use, costs, and quality of life in patients with multiple sclerosis (MS) in Germany. Six centers participated in the study. Patients were asked to complete a questionnaire, and a total of 737 patients returned it (response rate 66%). The questionnaire provided information on all resource consumption, medical, and nonmedical, work absence, informal care related to their MS, and quality of life (EuroQol). Simultaneously, medical charts were also abstracted for a subsample of 202 patients for comparison between answers in the questionnaires and registered data. Levels of disability were assessed using the Expanded Disability Status Scale. The mean age of the cohort was 41.9±14.1 years (disease onset 33.4), mean EDSS score 4.4 (range 1.0–9.5), and mean utility measured by EQ-5D 0.552±0.331). Mean total cost per patient and year was 65,400 DM, adjusted for use of interferons, which was higher in this sample than the current average use in Germany. When this cost is extrapolated to an estimated patient population of 120,000, total costs to society are estimated at 7.85 billion DM. Direct costs represented 57.5%, informal care accounted for 12.1% and indirect costs amounted to 42.5%. Public payers pay for an estimated 24,800 DM per patient or 38% of total costs. All types of costs (direct, informal care, indirect) increased with increasing disability, while utilities decreased.

Therapy with Intravenous Immunoglobulins: Complications and Side-Effects

Therapy with intravenous immunoglobulins (IVIG) is thought to be a safe treatment for a number of immune-mediated neurological diseases. Published data about prevalence of adverse effects range from 11 to 81%. The purpose of our study was to present a representative view on adverse effects by analysis of a large cohort of patients treated by IVIG. In a prospective study, we analysed 117 patients (age 17–79 years) who were treated with IVIG for various neurological diseases including chronic inflammatory demyelinating polyneuropathy, diabetic amyotrophy, inclusion body myositis, multiple sclerosis, Guillain-Barré syndrome, Miller-Fisher syndrome, multifocal motor neuropathy, myasthenia gravis and polymyositis. IVIG therapy was applied at a dose of 0.4 g/kg body weight/day in a total of 408 therapy courses. 42.7% showed adverse events. The majority of patients presented with minor adverse effects, mostly asymptomatic laboratory changes. Rash or mild headache occurred in 8 patients, especially when IVIG was given with infusion flow higher than 10 g/h. Two patients showed a severe complication with deep vein thrombosis. In summary, beside its effectiveness in immune mediated neurological diseases, therapy with IVIG seems to be a safe therapy. Most patients show no or minor adverse effects. Patients with pre-existent disorders like heart or renal insufficiency or immobilised patients, however, may be at higher risk for complications.

MicroRNAs in multiple sclerosis and experimental autoimmune encephalomyelitis

MicroRNA (miRNA) are small non-coding RNA molecules about 21-25 nucleotides long. They control gene regulation by translational repression and cleavage. Several studies have shown that many miRNA are associated with the etiology of different diseases. Recent developments in diverse miRNA profiling platforms like microarray and quantitative real-time PCR may enable the identification of specific miRNA as novel diagnostic and predictive markers for various diseases. MiRNAs could even be used as therapeutic drug targets. Multiple sclerosis (MS) is a chronic autoimmune disease affecting the central nervous system. Dysregulated immune system processes result in demyelination of neurons and consequently, electrical impulses that travel along the nerves are disrupted resulting in the impairment of organs. In the past three years, there has been an increased interest in establishing miRNA-based biomarkers for MS. So far, there are six studies on miRNA expression in MS patients in which first miRNAs were discovered as potential disease markers. For instance, one study showed that blood levels of miR-145 can discriminate MS patients from healthy controls, and another showed that active lesions in the brain are characterized by a strong up-regulation of miR-155. Studies on experimental autoimmune encephalomyelitis (EAE), the animal model of MS, further support the significance of miRNA as e.g. mice with miR-155 deletion are highly resistant to EAE. Such investigations help to understand the molecular processes involved in the disease. The identification of miRNA markers that are associated with type of MS, individual disease activity or clinical progression under treatment may open new avenues for early diagnosis and optimized therapy of MS.