Neuromyelitis Optica in Austria in 2011: To Bridge the Gap between Neuroepidemiological Research and Practice in a Study Population of 8.4 Million People

Abstract

BackgroundIn 2008 the Austrian Task Force for Neuromyelitis Optica (NMO) started a nation-wide network for information exchange and multi-centre collaboration. Their aim was to detect all patients with NMO or NMO spectrum disorders (NMO-SD) in Austria and to analyse their disease courses and response to treatment.Methods(1) As of March 2008, 1957 serum samples (of 1557 patients) have been tested with an established cell based immunofluorescence aquaporin-4 antibody (AQP4-ab) assay with a high sensitivity and specificity (both >95%). All tests were performed in a single reference laboratory (Clinical Dept. of Neurology of the Innsbruck Medical University). (2) A nation-wide survey with several calls for participation (via email newsletters, articles in the official journal of the Austrian Society of Neurology, and workshops) was initiated in 2008. All collected data will be presented in a way that allows that every individual patient can be traced back in order to ensure transparency and to avoid any data distortion in future meta-analyses. The careful and detailed presentation allows the visualization and comparison of the different disease courses in real time span. Failure and response to treatment are made visible at one glance. Database closure was 31 December 2011. All co-operators were offered co-authorship.ResultsAll 71 NMO- or NMO-SD patients with AQP4-ab positivity (age range 12.3 to 79.6 years) were analysed in detail. Sex ratio (m:f = 1:7) and the proportion of patients without oligoclonal bands in cerebrospinal fluid (86.6%) were in line with previously published results. All identified patients were Caucasians.ConclusionsA nationwide collaboration amongst Austrian neurologists with good network communications made it possible to establish a database of 71 AQP4-ab positive patients with NMO/NMO-SD. This database is presented in detail and provides the basis for further studies and international cooperation in order to investigate this rare disease.

Neuromyelitis optica in Portugal (NEMIPORT) – A multicentre study

“…We found that a higher percentage of patients presenting with LETM had CSF pleocytosis when compared to the patients that presented with ON. Like in previous reports, brain MRI at disease onset was mostly normal or showed non-specific brain lesions [18][19][20]. With respect to spinal cord lesions, the results were also consistent with those of prior studies showing LETM in 52.5% of patients.…”

“…In spite of having found a higher percentage of patients with concomitant autoimmune disorders (15 patients, 22.4%) than it was reported in the French [16] (10.4%) and Hong Kong [18] (10.6%) studies, most of the encountered disorders were similar (mainly SLE and Sjogren's syndrome) except for the two cases of myasthenia gravis described in our cohort [13] and also in the Austrian one [20]. Since 66.7% of patients with autoimmune diseases had positive AQP4-IgG antibody, we hypothesize that its presence may be faced as an "autoimmune marker".…”

“…Interestingly, in our study no patient had a progressive course. Although higher female:male ratios, higher age at disease onset and higher percentage of relapsing remitting course have been reported [18][19][20] namely in cohorts with populations sizes similar to Portugal [18,20]. The CSF results are different from what we can find in the literature.…”

“…The CSF results are different from what we can find in the literature. In fact, in the majority of the patients there was no CSF pleocytosis and 8 out of 46 (17.4%) had OCB (around 12% in other studies) [19][20][21]. We found that a higher percentage of patients presenting with LETM had CSF pleocytosis when compared to the patients that presented with ON.…”

“…The percentage of AQP4-IgG positive patients is lower in our study (35.8%; CBA technique) than in the French [16] (54.0%; indirect immunofluorescence assay), the Danish [17] (62.0%; CBA technique), the Hong Kong [18] (88.9%, CBA) and the American multicentre one [19] (68.3%; indirect immunofluorescence assay). However, the total number of patients (namely of the NMOSD group) and the definition of NMOSD (some studies included in this group only patients that were AQP4-IgG seropositive) [18][19][20] must be taken into account. In fact, if we compare only with the definite NMO groups the results are in consonance between our study (52.4%) and the Danish [17] one (55.6%).…”