Ellen Iacobaeus

Variation in interleukin 7 receptor alpha chain (IL7R) influences risk of multiple sclerosis

Multiple sclerosis is a chronic, often disabling, disease of the central nervous system affecting more than 1 in 1,000 people in most western countries. The inflammatory lesions typical of multiple sclerosis show autoimmune features and depend partly on genetic factors. Of these genetic factors, only the HLA gene complex has been repeatedly confirmed to be associated with multiple sclerosis, despite considerable efforts. Polymorphisms in a number of non-HLA genes have been reported to be associated with multiple sclerosis, but so far confirmation has been difficult. Here, we report compelling evidence that polymorphisms in IL7R, which encodes the interleukin 7 receptor α chain (IL7Rα), indeed contribute to the non-HLA genetic risk in multiple sclerosis, demonstrating a role for this pathway in the pathophysiology of this disease. In addition, we report altered expression of the genes encoding IL7Rα and its ligand, IL7, in the cerebrospinal fluid compartment of individuals with multiple sclerosis.

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.

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.

Autologous haematopoietic stem cell transplantation for aggressive multiple sclerosis: the Swedish experience

Background Autologous haematopoietic stem cell transplantation (HSCT) is a viable option for treatment of aggressive multiple sclerosis (MS). No randomised controlled trial has been performed, and thus, experiences from systematic and sustained follow-up of treated patients constitute important information about safety and efficacy. In this observational study, we describe the characteristics and outcome of the Swedish patients treated with HSCT for MS. Methods Neurologists from the major hospitals in Sweden filled out a follow-up form with prospectively collected data. Fifty-two patients were identified in total; 48 were included in the study and evaluated for safety and side effects; 41 patients had at least 1 year of follow-up and were further analysed for clinical and radiological outcome. In this cohort, 34 patients (83%) had relapsing-remitting MS, and mean follow-up time was 47 months. Results At 5 years, relapse-free survival was 87%; MRI event-free survival 85%; expanded disability status scale (EDSS) score progression-free survival 77%; and disease-free survival (no relapses, no new MRI lesions and no EDSS progression) 68%. Presence of gadolinium-enhancing lesions prior to HSCT was associated with a favourable outcome (disease-free survival 79% vs 46%, p=0.028). There was no mortality. The most common long-term side effects were herpes zoster reactivation (15%) and thyroid disease (8.4%). Conclusions HSCT is a very effective treatment of inflammatory active MS and can be performed with a high degree of safety at experienced centres.

Analysis of cerebrospinal fluid and cerebrospinal fluid cells from patients with multiple sclerosis for detection of JC virus DNA

Objective 1) To determine whether JC virus (JCV) DNA was present in the cerebrospinal fluid (CSF) and blood from patients with multiple sclerosis (MS) in comparison with controls and 2) to find out if our clinical material, based on presence of JCV DNA, included any patient at risk for progressive multifocal leukoencephalopathy (PML). Methods The prevalence of JCV DNA was analyzed in CSF and plasma from 217 patients with MS, 86 patients with clinically isolated syndrome (CIS), and 212 patients with other neurological diseases (OND). In addition, we analyzed CSF cells, the first report of JCV DNA in CSF cells in a single sample, and peripheral blood cells in a subgroup of MS (n = 49), CIS (n = 14) and OND (n = 53). Results A low copy number of JCV DNA was detected in one MS cell free CSF sample and in one MS CSF cell samples. None of these had any signs of PML or developed this disease during follow-up. In addition, two OND plasma samples were JCV DNA positive, whereas all the other samples had no detectable virus. Conclusion A low copy number of JCV DNA may occasionally be observed both in MS and other diseases and may occur as part of the normal biology of JC virus in humans. This study does not support the hypothesis that patients with MS would be at increased risk to develop PML, and consequently screening of CSF as a measurable risk for PML is not useful.

The Expression of VEGF-A Is Down Regulated in Peripheral Blood Mononuclear Cells of Patients with Secondary Progressive Multiple Sclerosis

Background Most patients with relapsing-remitting multiple sclerosis (RRMS) eventually enter a secondary progressive (SPMS) phase, characterized by increasing neurological disability. The mechanisms underlying transition to SPMS are unknown and effective treatments and biomarkers are lacking. Vascular endothelial growth factor-A (VEGF-A) is an angiogenic factor with neuroprotective effects that has been associated with neurodegenerative diseases. SPMS has a prominent neurodegenerative facet and we investigated a possible role for VEGF-A during transition from RRMS to SPMS. Methodology/Principal Findings VEGF-A mRNA expression in peripheral blood mononuclear (PBMC) and cerebrospinal fluid (CSF) cells from RRMS (n = 128), SPMS (n = 55) and controls (n = 116) were analyzed using real time PCR. We demonstrate reduced expression of VEGF-A mRNA in MS CSF cells compared to controls (p<0.001) irrespective of disease course and expression levels are restored by natalizumab treatment(p<0.001). VEGF-A was primarily expressed in monocytes and our CSF findings in part may be explained by effects on relative monocyte proportions. However, VEGF-A mRNA expression was also down regulated in the peripheral compartment of SPMS (p<0.001), despite unchanged monocyte counts, demonstrating a particular phenotype differentiating SPMS from RRMS and controls. A possible association of allelic variability in the VEGF-A gene to risk of MS was also studied by genotyping for six single nucleotide polymorphisms (SNPs) in MS (n = 1114) and controls (n = 1234), which, however, did not demonstrate any significant association between VEGF-A alleles and risk of MS. Conclusions/Significance Expression of VEGF-A in CSF cells is reduced in MS patients compared to controls irrespective of disease course. In addition, SPMS patients display reduced VEGF-A mRNA expression in PBMC, which distinguish them from RRMS and controls. This indicates a possible role for VEGF-A in the mechanisms regulating transition to SPMS. Decreased levels of PBMC VEGF-A mRNA expression should be further evaluated as a biomarker for SPMS.

Cerebrospinal fluid anti-myelin antibodies are related to magnetic resonance measures of disease activity in multiple sclerosis.

Objective: Recent studies reported contrasting results with respect to the presence of anti-myelin protein antibodies in multiple sclerosis (MS) and their relation with disease activity. This may be due to the heterogeneous specificity of autoantibodies in MS and the inability of most methods to detect pathogenically relevant antibodies. Here, myelin particles were used to detect anti-myelin antibodies in the CSF of MS patients. Subsequently, their relation with MRI parameters was evaluated. Methods: Anti-myelin IgG antibody reactivity was determined in the CSF of patients with MS (n = 65) and clinically isolated syndrome (CIS, n = 37) using a novel flow cytometry based assay. In addition, the CSF of patients with other neurological diseases (OND, n = 17), inflammatory neurological diseases (IND, n = 33) and controls (n = 22) was tested. Results: Compared with controls, increased anti-myelin IgG antibody reactivity was most frequently found in the CSF of patients with CIS (46%, p = 0.002), relapsing–remitting MS (56%, p<0.001) and secondary progressive MS (55%, p<0.001), together constituting 85% of all positive CSF samples. In contrast, elevated anti-myelin IgG antibody reactivity was present in a minority of IND patients (21%), marginally present in controls (5%) and absent in OND patients (0%). Most strikingly, anti-myelin IgG antibody reactivity was related to the number of T2 lesions (r = 0.31, p = 0.041) and gadolinium enhancing T1 lesions (r = 0.37, p = 0.016) on brain MRI in CIS and relapse onset MS patients. Conclusion: CSF anti-myelin IgG antibodies are promising specific biomarkers in CIS and relapse onset MS and correlate with MR measures of disease activity.

Consensus guidelines for lumbar puncture in patients with neurological diseases.

Cerebrospinal fluid collection by lumbar puncture (LP) is performed in the diagnostic workup of several neurological brain diseases. Reluctance to perform the procedure is among others due to a lack of standards and guidelines to minimize the risk of complications, such as post‐LP headache or back pain.

Phenotypic and functional alterations of myeloid-derived suppressor cells during the disease course of multiple sclerosis

Multiple sclerosis (MS) is a chronic autoimmune disease of the central nervous system involving dysregulated encephalitogenic T cells. Myeloid‐derived suppressor cells (MDSCs) have been recognized for their important function in regulating T‐cell responses. Recent studies have indicated a role for MDSCs in autoimmune diseases, but their significance in MS is not clear. Here, we assessed the frequencies of CD14+HLA‐DRlow monocytic MDSCs (Mo‐MDSCs) and CD33+CD15+CD11b+HLA‐DRlow granulocytic MDSCs (Gr‐MDSCs) and investigated phenotypic and functional differences of Mo‐MDSCs at different clinical stages of MS and in healthy subjects (HC). Increased frequencies of Mo‐MDSCs (P < 0.05) and Gr‐MDSCs (P < 0.05) were observed in relapsing‐remitting MS patients during relapse (RRMS‐relapse) compared to stable RRMS (RRMS‐rem). Secondary progressive MS (SPMS) patients displayed a decreased frequency of Mo‐MDSCs and Gr‐MDSCs compared to HC (P < 0.05). Mo‐MDSCs within RRMS patients expressed significantly higher cell surface protein levels of CD86 and CD163 compared to SPMS patients. Mo‐MDSCs within SPMS exhibited decreased mRNA expression of interleukin‐10 and heme oxygenase 1 compared to RRMS and HC. Analysis of T‐cell regulatory function of Mo‐MDSCs demonstrated T‐cell suppressive capacity in RRMS and HCs, while Mo‐MDSCs of SPMS promoted autologous T‐cell proliferation, which aligned with a differential cytokine profile compared to RRMS and HCs. This study is the first to show phenotypic and functional shifts of MDSCs between clinical stages of MS, suggesting a role for MDSCs as a therapeutic target to prevent MS disease progression.