Roberto Bergamaschi

Clinical characteristics, course and prognosis of relapsing Devic’s Neuromyelitis Optica

Abstract.Objectives:To evaluate the clinical characteristics, course and prognosis of Devic’s neuromyelitis optica (DNO), to evaluate the prognostic role of demographic and clinical features, to evaluate the current DNO diagnostic criteria.Methods:Demographic, clinical, CSF and MRI data of patients affected by DNO were collected from fifteen Italian MS centres. Inclusion criteria were: 1) two or more acute episodes of neurological dysfunction indicating involvement of the optic nerve and spinal cord, in a simultaneous or subsequent temporal relationship; 2) no evidence of lesions beyond the optic nerve or the spinal cord; 3) brain MRI at onset negative or non-specific for multiple sclerosis (MS) (white matter lesions ≤ 2). Disability was scored by means of Kurtzke’s Expanded Disability Status Scale (EDSS).Results:46 patients with relapsing DNO were included, 37 females and 9 males, with mean age at onset of 40.1 ± 16.3 years (range 12–77 years). The follow up duration was 8.8 ± 3.5 years, the mean annualised relapse rate was 1.3 ± 1.2. After 5, 10 and 15 years EDSS 3.0 was reached respectively by 65%, 82 % and 86% of cases, EDSS 6.0 respectively by 42%, 53 % and 69% of cases, EDSS 10 respectively by 8%, 12% and 23% of cases. The probability of reaching EDSS 3 was statistically correlated with age at onset, interval between the first and 2nd attack, and relapse rate. The probability of reaching EDSS 6.0 was correlated with the residual EDSS at onset and to relapse rate.During the follow up, brain white matter lesions appeared in 8 subjects. Spinal cord MRI showed lesions extending across 3 or more segments in 39 subjects, only 1 lesion involving 1 segment in 4 subjects, and was normal in 3 subjects. One or more CSF abnormalities were found at least once in 29/44 patients (65.9 %), the most frequent findings being pleocytosis (38.6 %), oligoclonal bands (34.1 %), high protein level (25 %), and high albumin ratio (20.5 %).Conclusions:DNO has a poor prognosis in most cases. Compared with MS, DNO patients have a higher age at onset, females are more frequently affected, the course is more severe. Brain and spinal cord MRI permit the differentiation of DNO from MS. CSF supports the probability of DNO if it shows increased cells and proteins.

Antibody to aquaporin 4 in the diagnosis of neuromyelitis optica.

Background Neuromyelitis optica (NMO) is a demyelinating disease of the central nervous system (CNS) of putative autoimmune aetiology. Early discrimination between multiple sclerosis (MS) and NMO is important, as optimum treatment for both diseases may differ considerably. Recently, using indirect immunofluorescence analysis, a new serum autoantibody (NMO-IgG) has been detected in NMO patients. The binding sites of this autoantibody were reported to colocalize with aquaporin 4 (AQP4) water channels. Thus we hypothesized that AQP4 antibodies in fact characterize NMO patients. Methods and Findings Based on these observations we cloned human water channel AQP4, expressed the protein in a eukaryotic transcription/translation system, and employed the recombinant AQP4 to establish a new radioimmunoprecipitation assay (RIPA). Indeed, application of this RIPA showed that antibodies against AQP4 exist in the majority of patients with NMO (n = 37; 21 positive) as well as in patients with isolated longitudinally extensive transverse myelitis (n = 6; six positive), corresponding to a sensitivity of 62.8% and a specificity of 98.3%. By contrast, AQP4 antibodies were virtually absent in 291 other participants, which included patients with MS (n = 144; four positive), patients with other inflammatory and noninflammatory neurological diseases (n = 73; one positive), patients with systemic autoimmune diseases (n = 45; 0 positive), and healthy participants (n = 29; 0 positive). Conclusions In the largest series reported so far to our knowledge, we quantified AQP4 antibodies in patients with NMO versus various other diseases, and showed that the aquaporin 4 water channel is a target antigen in a majority of patients with NMO. The newly developed assay represents a highly specific, observer-independent, and easily reproducible detection method facilitating clinically relevant discrimination between NMO, MS, and other inflammatory diseases.

NMO-IgG in the diagnosis of neuromyelitis optica

Recently, a newly detected serum autoantibody (called NMO-IgG) has been reported to distinguish between neuromyelitis optica (NMO) and multiple sclerosis (MS),1 and revised diagnostic criteria for NMO giving a crucial role to this antibody have been suggested.2 This proposal has important clinical implications and therefore demands independent confirmation. We studied 36 unselected patients with NMO (33 relapsing, three monophasic). All patients met the 1999 criteria of Wingerchuk et al.3 Spinal cord lesions in three or more segments were present in 35 of 36. Median follow-up from onset was 38 months. In addition, we tested 80 patients with MS according to the revised McDonald criteria4 (71% relapsing-remitting, 20% secondary progressive, 9% primary progressive), five patients with longitudinally extensive transverse myelitis (LETM),1,5 11 patients with non-LETM myelitis, 21 with miscellaneous neurologic disorders, and 25 healthy controls. NMO-IgG was detected by indirect immunofluorescence.1 Briefly, adult mouse cerebellum cryosections (10 μm) were incubated with 10% phosphate-buffered formalin for 4 minutes. After three washes in phosphate-buffered saline (PBS), detergent (1% CHAPS in PBS) was applied for 4 minutes. After …

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.

Cerebrospinal fluid antibodies to aquaporin-4 in neuromyelitis optica and related disorders: frequency, origin, and diagnostic relevance

BackgroundIn 70-80% of cases, neuromyelitis optica (NMO) is associated with highly specific serum auto-antibodies to aquaporin-4 (termed AQP4-Ab or NMO-IgG). Recent evidence strongly suggests that AQP4-Ab are directly involved in the immunopathogenesis of NMO.ObjectiveTo assess the frequency, syndrome specificity, diagnostic relevance, and origin of cerebrospinal fluid (CSF) AQP4-Ab in patients with NMO spectrum disorders (NMOSD).Methods87 CSF samples from 37 patients with NMOSD and 42 controls with other neurological diseases were tested for AQP4-Ab in a cell based assay using recombinant human AQP4. Twenty-three paired CSF and serum samples from AQP4-Ab seropositive NMOSD patients were further analysed for intrathecal IgG synthesis to AQP4.ResultsAQP4-Ab were detectable in 68% of CSF samples from AQP4-Ab seropositive patients with NMOSD, but in none of the CSF samples from AQP4-Ab seronegative patients with NMOSD and in none of the control samples. Acute disease relapse within 30 days prior to lumbar puncture, AQP4-Ab serum titres >1:250, and blood-CSF barrier dysfunction, but not treatment status, predicted CSF AQP4-Ab positivity. A positive AQP4-specific antibody index was present in 1/23 samples analysed.ConclusionsAQP4-Ab are detectable in the CSF of most patients with NMOSD, mainly during relapse, and are highly specific for this condition. In the cohort analysed in this study, testing for CSF AQP4-Ab did not improve the sensitivity and specificity of the current diagnostic criteria for NMO. The substantial lack of intrathecal AQP4-Ab synthesis in patients with NMOSD may reflect the unique localisation of the target antigen at the blood brain barrier, and is important for our understanding of the immunopathogenesis of the disease.

Persistence on therapy and propensity matched outcome comparison of two subcutaneous interferon beta 1a dosages for multiple sclerosis

Objectives To compare treatment persistence between two dosages of interferon β-1a in a large observational multiple sclerosis registry and assess disease outcomes of first line MS treatment at these dosages using propensity scoring to adjust for baseline imbalance in disease characteristics. Methods Treatment discontinuations were evaluated in all patients within the MSBase registry who commenced interferon β-1a SC thrice weekly (n = 4678). Furthermore, we assessed 2-year clinical outcomes in 1220 patients treated with interferon β-1a in either dosage (22 µg or 44 µg) as their first disease modifying agent, matched on propensity score calculated from pre-treatment demographic and clinical variables. A subgroup analysis was performed on 456 matched patients who also had baseline MRI variables recorded. Results Overall, 4054 treatment discontinuations were recorded in 3059 patients. The patients receiving the lower interferon dosage were more likely to discontinue treatment than those with the higher dosage (25% vs. 20% annual probability of discontinuation, respectively). This was seen in discontinuations with reasons recorded as “lack of efficacy” (3.3% vs. 1.7%), “scheduled stop” (2.2% vs. 1.3%) or without the reason recorded (16.7% vs. 13.3% annual discontinuation rate, 22 µg vs. 44 µg dosage, respectively). Propensity score was determined by treating centre and disability (score without MRI parameters) or centre, sex and number of contrast-enhancing lesions (score including MRI parameters). No differences in clinical outcomes at two years (relapse rate, time relapse-free and disability) were observed between the matched patients treated with either of the interferon dosages. Conclusions Treatment discontinuations were more common in interferon β-1a 22 µg SC thrice weekly. However, 2-year clinical outcomes did not differ between patients receiving the different dosages, thus replicating in a registry dataset derived from “real-world” database the results of the pivotal randomised trial. Propensity score matching effectively minimised baseline covariate imbalance between two directly compared sub-populations from a large observational registry.

Polyspecific, antiviral immune response distinguishes multiple sclerosis and neuromyelitis optica

Background: A polyspecific, intrathecal humoral immune response against neurotropic viruses such as measles, rubella and varicella zoster virus (MRZ reaction, MRZR) is present in 80–100% of patients with multiple sclerosis (MS), but has not to date been evaluated in patients with neuromyelitis optica (NMO). Aims: To evaluate whether MRZR distinguishes NMO and MS. Methods: 20 patients with NMO and 42 with MS were included. The intrathecal synthesis of antibodies against measles, rubella and varicella zoster virus was detected by calculation of the respective antibody indices (AI). Results: A positive MRZ reaction, as defined by a combination of at least two positive AIs, was found in 37/42 MS, but in only 1/20 NMO patients (p<0.0001). Median AI values differed significantly between the groups (p<0.0005). Conclusions: The polyspecific antiviral humoral immune response characteristic for MS is widely missing in NMO, irrespective of the NMO-IgG status of the patients. Our findings further strengthen the case for NMO being pathologically distinct from MS.

A post-marketing study on interferon beta 1b and 1a treatment in relapsing-remitting multiple sclerosis: different response in drop-outs and treated patients.

Background: Interferon β 1b (Betaferon) and 1a (Avonex) were licensed in Italy for treating relapsing-remitting multiple sclerosis in February 1996 and August 1997, respectively. Objectives: To evaluate the effectiveness of these agents on the basis of clinical experience in northern Italian multiple sclerosis centres. Design: Clinical data on patients with relapsing-remitting multiple sclerosis were collected on an appropriate form from 65 centres in northern Italy. Intention to treat analysis was not possible, so patients who discontinued treatment (drop-outs) and who continued treatment (treated) were analysed separately. The main outcome measures were annual relapse frequency, number of relapse-free patients, mean change in extended disability status scale score (EDSS), and number of patients who worsened. Results: 1481 patients were included; 834 were treated with Betaferon and 647 with Avonex for mean periods of 21.4 and 12.0 months, respectively. Basal EDSS was 2.37 and 2.17, respectively, and relapse frequency was 1.62 and 1.45. The annual relapse rate decreased by more than 60% with Betaferon and 55% with Avonex. The proportions of relapse-free, improved, and worsened patients were similar in the two groups. More patients interrupted treatment with Betaferon (41.1%) than with Avonex (15.3%); such patients showed more active disease at baseline and during treatment. The incidence of side effects was higher in Betaferon treated patients. Conclusions: The effectiveness of Betaferon and Avonex is confirmed. There was a more marked effect than expected from the experimental trial results. This might reflect differences in inclusion criteria, or, more likely, loss of drop-outs, favouring selective retention of responders.

Predicting secondary progression in relapsing-remitting multiple sclerosis : a Bayesian analysis

With the aid of a Bayesian statistical model of the natural course of relapsing remitting Multiple Sclerosis (MS), we identify short-term clinical predictors of long-term evolution of the disease, with particular focus on predicting onset of secondary progressive course (failure event) on the basis of patient information available at an early stage of disease. The model specifies the full joint probability distribution for a set of variables including early indicator variables (observed during the early stage of disease), intermediate indicator variables (observed throughout the course of disease, prefailure) and the time to failure. Our model treats the intermediate indicators as a surrogate response event, so that in right-censored patients, these indicators provide supplementary information pointing towards the unobserved failure times. Moreover, the full probability modelling approach allows the considerable uncertainty which affects certain early indicators, such as the early relapse rates, to be incorporated in the analysis. With such a model, the ability of early indicators to predict failure can be assessed more accurately and reliably, and explained in terms of the relationship between early and intermediate indicators. Moreover, a model with the aforementioned features allows us to characterize the pattern of disease course in high-risk patients, and to identify short-term manifestations which are strongly related to long-term evolution of disease, as potential surrogate responses in clinical trials. Our analysis is based on longitudinal data from 186 MS patients with a relapsing-remitting initial course. The following important early predictors of the time to progression emerged: age; number of neurological functional systems (FSs) involved; sphincter, or motor, or motor-sensory symptoms; presence of sequelae after onset. During the first 3 years of follow up, to reach EDSS> or =4 outside relapse, to have sphincter or motor relapses and to reach moderate pyramidal involvement were also found to be unfavourable prognostic factors.

Sex as a determinant of relapse incidence and progressive course of multiple sclerosis

The aim of this work was to evaluate sex differences in the incidence of multiple sclerosis relapses; assess the relationship between sex and primary progressive disease course; and compare effects of age and disease duration on relapse incidence. Annualized relapse rates were calculated using the MSBase registry. Patients with incomplete data or <1 year of follow-up were excluded. Patients with primary progressive multiple sclerosis were only included in the sex ratio analysis. Relapse incidences over 40 years of multiple sclerosis or 70 years of age were compared between females and males with Andersen-Gill and Tweedie models. Female-to-male ratios stratified by annual relapse count were evaluated across disease duration and patient age and compared between relapse-onset and primary progressive multiple sclerosis. The study cohort consisted of 11 570 eligible patients with relapse-onset and 881 patients with primary progressive multiple sclerosis. Among the relapse-onset patients (82 552 patient-years), 48,362 relapses were recorded. Relapse frequency was 17.7% higher in females compared with males. Within the initial 5 years, the female-to-male ratio increased from 2.3:1 to 3.3:1 in patients with 0 versus ≥4 relapses per year, respectively. The magnitude of this sex effect increased at longer disease duration and older age (P < 10(-12)). However, the female-to-male ratio in patients with relapse-onset multiple sclerosis and zero relapses in any given year was double that of the patients with primary progressive multiple sclerosis. Patient age was a more important determinant of decline in relapse incidence than disease duration (P < 10(-12)). Females are predisposed to higher relapse activity than males. However, this difference does not explain the markedly lower female-to-male sex ratio in primary progressive multiple sclerosis. Decline in relapse activity over time is more closely related to patient age than disease duration.