Lou Brundin

A consensus protocol for the standardization of cerebrospinal fluid collection and biobanking

There is a long history of research into body fluid biomarkers in neurodegenerative and neuroinflammatory diseases. However, only a few biomarkers in CSF are being used in clinical practice. One of the most critical factors in CSF biomarker research is the inadequate powering of studies because of the lack of sufficient samples that can be obtained in single-center studies. Therefore, collaboration between investigators is needed to establish large biobanks of well-defined samples. Standardized protocols for biobanking are a prerequisite to ensure that the statistical power gained by increasing the numbers of CSF samples is not compromised by preanalytical factors. Here, a consensus report on recommendations for CSF collection and biobanking is presented, formed by the BioMS-eu network for CSF biomarker research in multiple sclerosis. We focus on CSF collection procedures, preanalytical factors, and high-quality clinical and paraclinical information. The biobanking protocols are applicable for CSF biobanks for research targeting any neurologic disease.

T Cell Ig- and Mucin-Domain-Containing Molecule-3 (TIM-3) and TIM-1 Molecules Are Differentially Expressed on Human Th1 and Th2 Cells and in Cerebrospinal Fluid-Derived Mononuclear Cells in Multiple Sclerosis

T cell Ig- and mucin-domain-containing molecules (TIMs) comprise a recently described family of molecules expressed on T cells. TIM-3 has been shown to be expressed on murine Th1 cell clones and has been implicated in the pathogenesis of Th1-driven experimental autoimmune encephalomyelitis. In contrast, association of TIM-1 polymorphisms to Th2-related airway hyperreactivity has been suggested in mice. The TIM molecules have not been investigated in human Th1- or Th2-mediated diseases. Using real-time (TaqMan) RT-PCR, we show that human Th1 lines expressed higher TIM-3 mRNA levels, while Th2 lines demonstrated a higher expression of TIM-1. Analysis of cerebrospinal fluid mononuclear cells obtained from patients with multiple sclerosis revealed significantly higher mRNA expression of TIM-1 compared with controls. Moreover, higher TIM-1 expression was associated with clinical remissions and low expression of IFN-γ mRNA in cerebrospinal fluid mononuclear cells. In contrast, expression of TIM-3 correlated well with high expression of IFN-γ and TNF-α. These data imply the differential expression of human TIM molecules by Th1 and Th2 cells and may suggest their differential involvement in different phases of a human autoimmune disease.

Dynamics of Oligodendrocyte Generation and Myelination in the Human Brain

The myelination of axons by oligodendrocytes has been suggested to be modulated by experience, which could mediate neural plasticity by optimizing the performance of the circuitry. We have assessed the dynamics of oligodendrocyte generation and myelination in the human brain. The number of oligodendrocytes in the corpus callosum is established in childhood and remains stable after that. Analysis of the integration of nuclear bomb test-derived (14)C revealed that myelin is exchanged at a high rate, whereas the oligodendrocyte population in white matter is remarkably stable in humans, with an annual exchange of 1/300 oligodendrocytes. We conclude that oligodendrocyte turnover contributes minimally to myelin modulation in human white matter and that this instead may be carried out by mature oligodendrocytes, which may facilitate rapid neural plasticity.

Pivotal Advance: HMGB1 expression in active lesions of human and experimental multiple sclerosis

Multiple sclerosis (MS) is a chronic, inflammatory, demyelinating disease of the CNS, most frequently starting with a series of bouts, each followed by complete remission and then a secondary, progressive phase during which the neurological deficit increases steadily. The underlying molecular mechanisms responsible for disease progression are still unclear. Herein, we demonstrate that high mobility group box chromosomal protein 1 (HMGB1), a DNA‐binding protein with proinflammatory properties, is evident in active lesions of MS and experimental autoimmune encephalomyelitis (EAE) and that HMGB1 levels correlate with active inflammation. Furthermore, the expression of the innate HMGB1 receptors—receptor for advanced glycation end products, TLR2, and TLR4—was also highly increased in MS and rodent EAE. Additionally, in vitro activation of rodent CNS‐derived microglia and bone marrow‐derived macrophages demonstrated that microglia were equally as capable as macrophages of translocating HMGB1 following LPS/IFN‐γ stimulation. Significant expression of HMGB1 and its receptors on accumulating activated macrophages and resident microglia may thus provide a positive feedback loop that amplifies the inflammatory response during MS and EAE pathogenesis.

Combination of CSF N-acetylaspartate and neurofilaments in multiple sclerosis

Objective: Axonal degeneration is the likely cause of disease progression in multiple sclerosis (MS). Our previous results indicated that neuron-specific N-acetylaspartate (NAA) is a candidate CSF biomarker for disease progression in MS. The aim of this study was to explore the potential of NAA as an early biomarker of axonal damage in MS. Next, we wanted to know the additional value of measurement of NAA compared to other candidate markers for axonal damage, such as neurofilament subunits and tau protein. Methods: Levels of NAA, neurofilament light, neurofilament heavy, and tau were determined in CSF of patients with clinically isolated syndrome (CIS, n = 38), relapsing-remitting MS (RRMS, n = 42), secondary progressive MS (SPMS, n = 28), and primary progressive MS (PPMS, n = 6); patients without neurologic disease (ND, n = 28); noninflammatory neurologic controls (n = 18); and inflammatory neurologic controls (n = 39). Results: CSF NAA levels were decreased in patients with SPMS compared to ND controls, patients with CIS, and patients with RRMS. CSF NAA levels in patients with CIS and RRMS were similar to those in ND subjects. All axonal damage proteins showed specific patterns of changes and relations with disease activity measures. The neurofilament light chain levels were already increased in patients with CIS, especially in patients who converted to MS. The neurofilament heavy chain levels were highest in the patients with SPMS. Tau levels were similar in MS and ND. Conclusions: CSF N-acetylaspartate (NAA) levels were not different from patients without neurologic disease in early stages of multiple sclerosis, though decreased as the disease progressed. Combining CSF NAA and neurofilament levels yields information on different phases of axonal pathology.

Cerebrospinal fluid CXCL13 in multiple sclerosis: a suggestive prognostic marker for the disease course

Background: Levels of CXCL13, a potent B-cell chemoattractant, are elevated in the cerebrospinal fluid (CSF) during multiple sclerosis (MS) and are associated with markers of MS activity. Levels decrease upon effective treatments. Objective: Here we validate the potential role of CSF CXCL13 as a biomarker for aspects of MS in a large amount of clinical material, the majority collected at early diagnostic work-up. Methods: CXCL13 was measured by ELISA in 837 subjects: relapsing–remitting MS (RRMS; n = 323), secondary progressive MS (SPMS; n = 40), primary progressive MS (PPMS; n = 24), clinically isolated syndrome (CIS; n = 79), other neurological diseases (ONDs; n = 181), ONDs with signs of inflammation or viral/bacterial infections (iONDs; n = 176) and healthy controls (n = 14). Results: Subjects with viral/bacterial infections had extremely high CXCL13 levels compared to all included groups (p < 0.0001). CXCL13 was otherwise significantly higher in MS compared to the remaining controls (p < 0.0001), and CIS (p < 0.01). A significant and positive correlation between CXCL13 and relapse rate, the results obtained for the Expanded Disability Status Scale (EDSS) and the number of lesions detected by MRI was demonstrated. CXCL13 was increased in CIS conversion to clinically definite MS (p < 0.001). Oligoclonal immunoglobulin band (OCB)-positive CIS or MS had significantly increased CXCL13 levels compared to OCB-negative CIS or MS (p < 0.001 and p < 0.0001, respectively). Conclusion: CXCL13 was associated with disease exacerbations and unfavourable prognosis in RRMS. Increased CXCL13 was not specific for MS since subjects with viral/bacterial infections exhibited even higher levels. High levels predicted CIS conversion to MS. We suggest that measurement of CSF CXCL13 can be part of the armamentarium in the diagnostic and prognostic work-up in MS and be of help in future treatment decisions.

Efficacy and impact of botulinum toxin A on quality of life in patients with neurogenic detrusor overactivity : A randomized, placebo-controlled, double-blind study

Objective. To evaluate the effect of a single injection of 500 U of botulinum toxin A (BTX-A; Dysport®) on use of oral rescue medication, bladder compliance, continence and quality of life in a randomized, placebo-controlled, double-blind study in patients with incontinence due to neurogenic detrusor overactivity. As this group of patients often have severe symptoms, oral tolterodine was allowed as rescue medication and the amount of tolterodine consumed was our primary endpoint. Material and methods. A total of 31 patients with urinary leakage due to spinal cord injury, myelomeningocele, trauma at birth, multiple sclerosis and myelitis of another cause were randomized to intravesical injections of either 500 U of BTX-A or placebo. Intake of tolterodine and episodes of urinary leakage were registered. Cystometry was performed after 6, 12 and 26 weeks and quality of life was assessed. Results. Patients in the BTX-A group had a significantly lower intake of tolterodine throughout the study compared to those in the placebo group (p=0.003). Cystometric capacity was significantly higher at 6 (p<0.001) and 12 weeks (p=0.026) and maximum detrusor pressure and frequency of urinary leakage were significantly (p<0.01) lower during follow-up in the BTX-A group compared to the placebo group. In addition, many quality-of-life parameters were significantly improved in the BTX-A group compared to the placebo group. Conclusions. Intravesical injection of 500 U of BTX-A in patients with neurogenic detrusor instability was shown to be an effective treatment which reduced use of oral medication, high detrusor pressure and frequency of urinary leakage during the overall study period of 26 weeks. Quality of life was also significantly improved.

Neurogenesis in the adult spinal cord in an experimental model of multiple sclerosis

Multiple sclerosis is an inflammatory disease of the central nervous system characterized by inflammation, demyelination, axonal degeneration and accumulation of neurological disability. Previously, we demonstrated that stem cells constitute a possible endogenous source for remyelination. We now addressed the question of whether neurogenesis can occur in neuroinflammatory lesions. We demonstrated that, in experimental autoimmune encephalomyelitis, induced in rats 1,1′‐dioctadecyl‐6,6′‐di(4sulphopentyl)‐3,3,3′,3′tetramethylindocarbocyanin(DiI)‐labelled ependymal cells not only proliferated but descendants migrated to the area of neuroinflammation and differentiated into cells expressing the neuronal markers β‐III‐tubulin and NeuN. Furthermore, these cells were immunoreactive for bromodeoxyuridine and PCNA, markers for cells undergoing cell proliferation. Using the whole‐cell patch‐clamp technique on freshly isolated 1, DiI‐labelled cells from spinal cord lesions we demonstrated the ability of these cells to fire overshooting action potentials similar to those of immature neurones. We thus provide the first evidence for the initiation of neurogenesis in neuroinflammatory lesions in the adult spinal cord.

Increased levels of proinflammatory cytokines and nitric oxide metabolites in neuropsychiatric lupus erythematosus

OBJECTIVE To investigate systemic and intrathecal production of proinflammatory cytokines in relation to cerebrospinal fluid (CSF) nitric oxide (NO) release in patients with neuropsychiatric lupus erythematosus (NPLE). METHODS Thirty patients with NPLE rated as mild, moderate, or severe were studied and CSF was obtained from 21 of these. Cytokine mRNA expressing cells were detected by in situ hybridisation. Soluble cytokines were assessed by enzyme linked immunosorbent assay (ELISA). Nitrite and nitrate were determined by capillary electrophoresis. RESULTS Patients with NPLE had high numbers of lymphocytes expressing mRNA for tumour necrosis factor α (ΤΝFα), interferon γ, and interleukin 10 in blood. The number of peripheral blood TNFα mRNA positive cells correlated strongly with the level of NO metabolites in the CSF (r 2=0.69). Both the number of peripheral blood mononuclear cells expressing mRNA for TNFα as well as the CSF level of NO metabolites correlated with NPLE disease severity. CONCLUSION These data suggest that increased peripheral production of proinflammatory cytokines such as TNFα may contribute both to an increased production of NO in the central nervous system and to generation of clinical NPLE. The data also support the possibility that measurements of NO metabolites in CSF may be of value in the diagnosis of neurological symptoms related to SLE.

Consensus definitions and application guidelines for control groups in cerebrospinal fluid biomarker studies in multiple sclerosis.

The choice of appropriate control group(s) is critical in cerebrospinal fluid (CSF) biomarker research in multiple sclerosis (MS). There is a lack of definitions and nomenclature of different control groups and a rationalized application of different control groups. We here propose consensus definitions and nomenclature for the following groups: healthy controls (HCs), spinal anesthesia subjects (SASs), inflammatory neurological disease controls (INDCs), peripheral inflammatory neurological disease controls (PINDCs), non-inflammatory neurological controls (NINDCs), symptomatic controls (SCs). Furthermore, we discuss the application of these control groups in specific study designs, such as for diagnostic biomarker studies, prognostic biomarker studies and therapeutic response studies. Application of these uniform definitions will lead to better comparability of biomarker studies and optimal use of available resources. This will lead to improved quality of CSF biomarker research in MS and related disorders.