[Show abstract][Hide abstract]ABSTRACT: Objective:
Antibodies to cell surface central nervous system proteins help to diagnose conditions which often respond to immunotherapies. The assessment of antibody assays needs to reflect their clinical utility. We report the results of a multicentre study of aquaporin (AQP) 4 antibody (AQP4-Ab) assays in neuromyelitis optica spectrum disorders (NMOSD).
Coded samples from patients with neuromyelitis optica (NMO) or NMOSD (101) and controls (92) were tested at 15 European diagnostic centres using 21 assays including live (n=3) or fixed cell-based assays (n=10), flow cytometry (n=4), immunohistochemistry (n=3) and ELISA (n=1).
Results of tests on 92 controls identified 12assays as highly specific (0-1 false-positive results). 32 samples from 50 (64%) NMO sera and 34 from 51 (67%) NMOSD sera were positive on at least two of the 12 highly specific assays, leaving 35 patients with seronegative NMO/spectrum disorder (SD). On the basis of a combination of clinical phenotype and the highly specific assays, 66 AQP4-Ab seropositive samples were used to establish the sensitivities (51.5-100%) of all 21 assays. The specificities (85.8-100%) were based on 92 control samples and 35 seronegative NMO/SD patient samples.
The cell-based assays were most sensitive and specific overall, but immunohistochemistry or flow cytometry could be equally accurate in specialist centres. Since patients with AQP4-Ab negative NMO/SD require different management, the use of both appropriate control samples and defined seronegative NMOSD samples is essential to evaluate these assays in a clinically meaningful way. The process described here can be applied to the evaluation of other antibody assays in the newly evolving field of autoimmune neurology.
[Show abstract][Hide abstract]ABSTRACT: A high seroprevalence of Yo antibodies targeting cerebellar Purkinje cells was recently reported in children with attention deficit/hyperactivity disorder (ADHD). We investigated the presence of 8 paraneoplastic neurological syndrome (PNS)-associated antibodies including anti-Yo in 169 adult ADHD patients. No associations between ADHD and serum Yo antibodies or other antibodies associated with PNS were found. However, 10 out of 48 ADHD patient sera analyzed by immunofluorescence presented antibodies targeting cerebellar Purkinje cells. This reactivity probably represents the presence of low levels of antibodies against multiple cellular hitherto unknown antigens with little to no clinical significance.
Full-text · Article · Sep 2015 · Journal of Neuroimmunology
[Show abstract][Hide abstract]ABSTRACT: Anti interferon-beta (IFN-β) neutralizing antibodies (NAb) affect efficacy of treatment of multiple sclerosis patients, but exactly when the detrimental effects of NAbs offset therapeutic efficacy is debated. Quantification of intracellular pathway-specific phosphorylation by phospho-specific flow cytometry (phosphoflow) is a promising tool for evaluation of these effects in primary immune cells from treated patients at the single-cell level.
Samples for phosphoflow and gene expression changes were collected before administration of IFN-β and at four, six, and eight hours thereafter. Patients were NAb negative (n = 3) or were NAb positive with low/medium (n = 1) or high (n = 2) NAb titers. Levels of phosphorylation of six Stat transcription factors (pStat) in seven cell subtypes and expression levels of 71 pathway-specific genes in whole blood were measured. The data was subjected to principal component analysis (PCA), fifty-fifty MANOVA, ANOVA, and partial least square regression (PLSR).
PCA of pStat levels clustered patients according to NAb class independently of time. PCA of gene expression data clustered patients according to NAb class but was affected by time and treatment. In the fifty-fifty MANOVA, NAb class was significant for both pStat levels and gene expression data. The ANOVA identified pStat1 protein in several cell subtypes as significantly affected by NAb class. The best fitting model for NAb prediction based on PLSR included pStat1 in monocytes, T cells, or lymphocytes and pStat3 in monocytes (r = 0.97). Gene expression data were slightly less predictive of NAb titers.
Based on this proof of concept study, we hypothesize that NAb effects can be monitored by evaluation of a single biomarker, pStat1, in either monocytes or T cells by phosphoflow directly after IFN-β administration. The method will significantly reduce cost relative to labor intensive in vitro methods and offers a patient-specific approach to NAb evaluation.
[Show abstract][Hide abstract]ABSTRACT: Onconeural antibodies are important in the detection of paraneoplastic neurological syndromes (PNS). The avidity of Hu, Yo, and CRMP5 antibodies from 100 patients was determined by immunoprecipitation (IP), and 13 of the Yo positive sera were also tested by surface plasmon resonance (SPR). There was a significant association between the results from IP and SPR. Yo antibodies had higher avidity than Hu and CRMP5 antibodies, and both high- and low-avidity antibodies were associated with tumors and PNS. High-avidity Yo antibodies were mainly associated with ovarian cancer, whereas high-avidity Hu and CRMP5 antibodies were mainly associated with small-cell lung cancer. Low-avidity CRMP5 and Yo antibodies were less often detected by a commercial line blot than high-avidity antibodies. The failure to detect low-avidity onconeural antibodies may result in under diagnosis of PNS.
No preview · Article · Jun 2013 · Cancer Immunology and Immunotherapy
[Show abstract][Hide abstract]ABSTRACT: Background
We report a case of childhood onset, generalized dystonia due to slowly progressive bilateral striatal necrosis associated with anti-N-methyl-D-aspartate receptor (NMDAR) antibodies. This clinical phenotype has not been previously associated with NMDA receptor autoimmunity.
An eighteen year old man presented with a history of childhood-onset, progressive generalized dystonia. Clinical examination revealed a pure generalized dystonia with no cognitive or other neurological findings. Magnetic resonance imaging showed bilateral high T2 signal striatal lesions, which were slowly progressive over a period of nine years. New parts of the lesion showed restricted water diffusion suggesting cytotoxic oedema. Positron emission tomography of the brain showed frontal hypermetabolism and cerebellar hypometabolism. Antibodies against the NR1 subunit of the NMDA receptor were detected in the patient’s serum and cerebrospinal fluid. There was no neoplasia or preceding infection or vaccination.
This is the first report of chronic progressive bilateral striatal necrosis associated with anti-NMDAR antibodies. Our findings expand the clinical spectrum of disease associated with anti-NMDAR antibodies and suggest that these should be included in the work-up of dystonia with striatal necrosis.
[Show abstract][Hide abstract]ABSTRACT: Background and purpose:
Our population-based long-term follow-up of young ischaemic stroke patients and controls showed 10-fold increased mortality and fivefold increased arterial event rate nearly 12 years after study inclusion. We now assess memory, anxiety, depression and sleep in relation to employment and functional outcome, treatment goals and results from a last alive-dead survey.
Patients (n = 232) ≤ 49 years with an index-stroke between 1988 and 1997 were retrospectively selected and compared with age- and sex-matched controls (n = 453). At follow-up from 2004 to 2005, 144 (77%) of 187 patients were clinically examined. Self-assessment information about memory problems, anxiety, depression, sleeping problems, education and employment was compared with answers from standardized questionnaires from 167 controls. Functional outcome was measured by the modified Rankin Scale (mRS).
Patients compared with controls had more memory problems (41.0% vs. 5.4%, P < 0.001), anxiety (19.4% vs. 9%, P = 0.009), depression (29.2% vs. 13.2%, P = 0.001) and sleeping problems (36.1% vs. 19.2%, P = 0.001). In the multiple regression analysis male gender (OR 9.3, 95%CI 0.10-0.61, P = 0.002), normal memory (OR 12.7, 95%CI 0.07-0.47, P < 0.001) and mRS 0-1 (OR 15.7, 95%CI 0.002-0.12, P < 0.001) were factors for full-time employment. Blood pressure was < 140/90 mmHg in 39% of patients, 49% stopped smoking and 38.2% used statins. After a mean observation time of 18.3 years, 63 (27.2%) of 232 patients were dead.
Our data show a heterogeneous prognosis and high mortality even for long-time survivors of ischaemic stroke at a young age. Prospective studies of young stroke patients and controls are necessary for direct comparison.
No preview · Article · Jan 2013 · European Journal of Neurology
[Show abstract][Hide abstract]ABSTRACT: Chronic immune-mediated demyelinating polyneuropathies can often lead to severe neurologic disability.
Literature review and personal experience with these types of neuropathies.
It is important to recognize these immune-mediated neuropathies as they respond to treatment.
No preview · Article · Jan 2013 · Acta neurologica Scandinavica. Supplementum
[Show abstract][Hide abstract]ABSTRACT: Multiple sclerosis (MS) is an immune-mediated disease of the central nervous system in genetically susceptible persons. Fcγ receptors (FcγR) are involved in autoimmune diseases.
Sixteen Norwegian patients with relapsing-remitting MS (RRMS) were studied to see whether treatment with either interferon-beta (INF-β) or glatiramer acetate (GA) influenced the proportion of FcγR1a, FcγR2a, and FcγR3b positive monocytes, granulocytes, or lymphocytes or FcγR1a, FcγR2a, and FcγR2b mRNA levels in leukocytes. One hundred and twenty-seven patients with RRMS and 54 Norwegian healthy blood donors were also analyzed for FcγR2b polymorphisms.
Interferon-beta or GA treatment initiated an increase in the proportion of FcγR positive lymphocytes, but did not cause major influence of the long-term proportion of FcγR positive leukocytes or their FcγR mRNA levels. No significant differences were observed between RRMS patients and healthy controls for the genotype and allele frequencies of FcγR2b polymorphisms.
INF-β or GA treatment probably has no major role in the regulation of FcγRs on immune cells in RRMS. Furthermore, polymorphisms of the inhibitory FcγR2b do not seem to influence the susceptibility for MS.
[Show abstract][Hide abstract]ABSTRACT: The aim of the present study was to identify proteins in cerebrospinal fluid (CSF) with different abundance between patients with relapsing-remitting multiple sclerosis (RRMS) and controls. Such proteins may be diagnostic biomarkers and contribute with novel information about the disease pathogenesis.
Cerebrospinal fluid from patients with RRMS (n = 17) and controls (n = 17) were trypsin digested and analyzed in a label-free fashion using liquid chromatography mass spectrometry. The resulting data were analyzed using SearchGUI, PeptideShaker, and the Progenesis software.
Two hundred and ninety-one proteins were identified, of which 32 were significantly differentially abundant between the patients with RRMS and controls (P-value ≤ 0.05, two or more peptides quantified). Among these were proteins which previously have been linked to MS, including immunoglobulin subunits, vitamin D-binding protein, apolipoprotein D, kallikrein-6, neuronal pentraxin receptor, Dickkopf-related protein 3, and contactin-1.
The study provides an overview of differentially abundant proteins between RRMS and controls, and a few of these are further discussed. It should be stressed that a larger verification study is needed to reveal the potential value of these proteins as biomarkers for RRMS and their involvement in the disease pathogenesis.
[Show abstract][Hide abstract]ABSTRACT: Paraneoplastic neuropathies are the most frequently reported paraneoplastic syndromes. The term paraneoplastic neuropathy is used for nerve damage in cancer that is not caused by direct spread of the cancer into the nerve, toxicity of treatments, metabolic derangement, virus infections or other obvious causes. It is generally accepted that an immune reaction to the cancer causes 'bystander' damage to the nerves. Paraneoplastic neuropathies are varied in character and require several therapeutic approaches. We undertook this review to systematically assess any available data from randomised controlled trials (RCTs) on the treatment of paraneoplastic neuropathies, concentrating first on evidence of the highest quality. Despite many reports on paraneoplastic neuropathy, we identified no RCTs for inclusion in this review. From the non-randomised evidence, we found only six studies, involving a total of 54 participants, that were suitable for inclusion in the discussion according to our predefined quality criteria. These studies were not readily comparable. At present there are no RCTs or quasi-RCTs of treatment for paraneoplastic neuropathies on which to base practice. There is only evidence from case series, case reports or expert opinion (class IV) for the effect of immunomodulation (intravenous immunoglobulin, plasma exchange, steroid treatment or chemotherapy) on paraneoplastic neuropathy.
No preview · Article · Dec 2012 · Cochrane database of systematic reviews (Online)
[Show abstract][Hide abstract]ABSTRACT: In the present study, we aimed to discover cerebrospinal fluid (CSF) proteins with significant abundance difference between early multiple sclerosis patients and controls, and do an initial verification of these proteins using selected reaction monitoring (SRM). iTRAQ and Orbitrap MS were used to compare the CSF proteome of patients with clinically isolated syndrome (CIS) (n=5), patients with relapsing-remitting multiple sclerosis that had CIS at the time of lumbar puncture (n=5), and controls with other inflammatory neurological disease (n=5). Of more than 1200 identified proteins, five proteins were identified with significant abundance difference between the patients and controls. In the initial verification using SRM we analyzed a larger patient and control cohort (n=132) and also included proteins reported as differentially abundant in multiple sclerosis in the literature. We found significant abundance difference for 11 proteins after verification, of which the five proteins alpha-1-antichymotrypsin, contactin-1, apolipoprotein D, clusterin, and kallikrein-6 were significantly differentially abundant in several of the group comparisons. This initial study form the basis for further biomarker verification studies in even larger sample cohorts, to determine if these proteins have relevance as diagnostic or prognostic biomarkers for multiple sclerosis.
Full-text · Article · Oct 2012 · Journal of proteomics
[Show abstract][Hide abstract]ABSTRACT: Immunogenicity of recombinant interferon-β (IFN-β) is a known complication in the therapy of relapsing-remitting multiple sclerosis (RRMS). Neutralizing antibodies (NAbs) that can interfere with efficacy are quantified using in vitro bioassays; however, these assays do not reveal the immunogenic state of the patient and are not predictive of treatment outcome.
Assessment of the impact of NAbs on IFN-β responsive cells and signalling pathways in peripheral blood mononuclear cells (PBMCs) with phospho-specific flow cytometry.
PBMCs from 10 IFN-β-treated patients with RRMS, two untreated patients, and two healthy controls were re-stimulated in autologous sera and media with a serial dilution of IFN-β (0-8000 U/ml) and levels of phosphorylation of STAT1/3/4/5/6 transcription factors were quantified in PBMC subtypes (NAb titres 0 to > 6000 neutralizing units). Data was subjected to principal component analysis, Hotelling's T (2), and partial least squares analysis.
Three significantly distinct clusters of individuals were revealed in autologous sera: therapy-naïve and healthy, treated NAb-negative, and treated NAb-positive. Compared with controls STATs signalling patterns were modulated in treated NAb-negative patients and inhibited in all treated NAb-positive patients independently of NAb titres. In media no clustering of patients could be found. The predictability of NAb titres based on the phospho-flow data was 74%.
Phospho-specific flow cytometry can delineate subset-specific cell responses that can act as surrogates for NAb exposure in blood. Immunogenic effects alter the response in primary cells even at low NAb levels. Cell line-based immunogenicity testing is not readily transferable to the immunogenic response in patients.
Full-text · Article · Jan 2012 · Multiple Sclerosis