by Results Staining pattern of NMO-IgG/AQP4-antibodies with the optimized immunohistochemistry technique The IHC-o specifically detects antibodies targeting AQP4 on the astroglial cell surface. the available tools for NMO-IgG/aquaporin-4-antibody detection. Introduction Neuromyelitis optica (NMO) is an inflammatory demyelinating disease of the central nervous system (CNS) characterized by Methyl Hesperidin predominant involvement of the optic nerves and spinal cord. For long time, NMO was thought to be a variant of multiple sclerosis (MS), although the prognosis and the response to the therapy was different [1]. The identification of a specific serum autoantibody marker by tissue-based indirect immunofluorescence (IIF), NMO-IgG, that bound to astrocytic membranes and the recognition of the target antigen as the water channel aquaporin-4 (AQP4) [2], led to expand the clinical spectrum of NMO to limited forms of the disease, to define a new set of diagnostic criteria, and to expedite the diagnosis and treatment of the patients [1,3,4,5,6,7,8]. Since the initial description of the NMO-IgG/AQP4-antibody, several techniques of detection with different sensitivities and specificities have been reported [9]. In a recent comparative study, IIF was the least and cell-based assay transfected with AQP4 (CBA) the most sensitive assay for NMO-IgG/AQP4-antibody detection [10,11]. In spite of assay refinement, around 20-30% of patients clinically diagnosed with NMO still remain NMO-IgG seronegative [10]. In neuronal autoimmune disorders of the CNS (or autoimmune encephalitis) most of the antibodies were initially identified using IIF or immunohistochemical techniques [12]. These techniques allow the possibility to identify new or coexisting antibodies. We observed that the optimized immunohistochemistry technique (IHC-o) developed for the detection of antibodies against cell surface/synaptic antigens [13], also identified the NMO-IgG pattern, which was easily recognized compared with conventional immunohistochemistry (IHC-c) [7,14]. The aim of the current study was to determine the Methyl Hesperidin sensitivity and specificity of the IHC-o to detect NMO-IgG/AQP4-antibodies, and compare them with those of conventional tissue-based assays, including IIF and IHC-c, and two CBA, an in-house assay (CBA-ih) with the AQP4-M23 isoform and a commercial assay (CBA-c) [15]. Material and Methods Patients Serum samples from 103 patients with definite NMO according to the revised diagnostic criteria of 2006 [5] (79% female, mean age at sampling 42.1 years, range 7-82 years) and 122 with inflammatory neurological diseases: 101 patients with MS, 30 of them with paired serum and cerebrospinal fluid (83 relapsing and 18 primary progressive MS) fulfilling the McDonalds criteria [16], and 21 with neurological syndromes associated with anti-neuronal antibodies (3 Hu, 2 Ri, 2 Yo, 3 CV2/CRMP5, 2 Ma2, 1 SOX, 3 GAD, 3 LGI1, and 2 CASPR2) were tested by IHC-o, CBA-ih, and CBA-c. The NMO samples were provided by 3 centers: Lyon Neuroscience Research Center, Methyl Hesperidin France; Neuroimmunology Group, Hospital Clinic de Barcelona, Spain; and the Department of Neurology, SMZ-Ost Donauspital, Vienna, Austria [17]. Thirty-nine NMO samples have been previously analysed by IIF [6] and other 43 samples by IHC-c [14]. These samples were further re-analyzed by IIF and IHC-c, respectively. Sera were coded before testing and all studies were evaluated by two investigators (RH and AS), blinded to the neurological diagnosis or results of the conventional tissue-based assays. Standard Protocol Approvals, Registrations, and Patient Consents Serum samples used in the study are deposited in the collection of biological samples named “neuroinmunologa” registered in the biobank of??Institut d’ Investigaci Biomdica August Pi i Sunyer (IDIBAPS), Barcelona, Spain, the biobank Neurobiotec (Hospices Civils de Lyon, France), and SMZost Donauspital, Vienna, Austria (EK11-056VK). Considering DP2 that the study was completely anonymous so no sample could be identified to a particular patient,?it was accepted to waive the specific written informed consent from the individuals or next of kin from the?Comit tico de Investigacin Clnica of Medical center Clnic de Barcelona. Pet handling procedures had been approved by the neighborhood Ethics Committee (99/1 College or university of Barcelona) as well as Methyl Hesperidin the Generalitat de Catalunya (1094/99), relative to the Directive 86/609/European union of the Western Commission. The scholarly study as explained.
