Aquaporin-4 and MOG autoantibody discovery in idiopathic transverse myelitis epidemiology.

OBJECTIVE: Diagnostic criteria from 2002 classify transverse myelitis (TM) as idiopathic or disease associated but predate the discovery of aquaporin-4 (AQP4)-immunoglobulin G (IgG) and myelin oligodendrocyte glycoprotein (MOG)-IgG, which associate with TM. Prior incidence estimates of idiopathic TM (ITM) range from 1 to 6.2 per 1 million. We sought to determine whether the population-based incidence and prevalence of ITM were reduced by testing patients with ITM for AQP4/MOG-IgG and reclassifying seropositive cases as having disease-associated TM. METHODS: For this observational study, we retrospectively identified all cases of incident (January 1, 2003-December 31, 2016) and prevalent (December 31, 2016) ITM in Olmsted County (85% white) by using the Rochester Epidemiology Project medical records linkage system. ITM was defined by the 2002 Transverse MyelitisConsortium Working Group diagnostic criteria. Available sera were tested for AQP4-IgG and MOG-IgG. RESULTS: Twenty-four patients (incident 22, prevalent 17) initially met 2002 ITM criteria (longitudinally extensive TM [LETM] 6). Sera were tested for AQP4-IgG in 22 of 24 (92%) and MOG-IgG in 21 of 24 (88%). Three seropositive cases (AQP4-IgG 2, MOG-IgG 1) were identified and reclassified as having disease-associated TM, accounting for 14% of total incident and 12% of total prevalent cases. AQP4-IgG and MOG-IgG seropositive cases represented 50% (3 of 6) of idiopathic LETM. After reclassification of seropositive patients, the final ITM incidence was 8.6 per 1,000,000 and prevalence was 7.9 per 100,000. Three cases of ITM (14%) subsequently fulfilled multiple sclerosis criteria within the study period. CONCLUSIONS: The availability of AQP4-IgG and MOG-IgG modestly reduced ITM incidence and prevalence, which remained higher than previously reported in this predominantly white population. Incorporation of these biomarkers into future revisions of TM diagnostic criteria should be considered.

Idiopathic aquaporin-4 antibody negative longitudinally extensive transverse myelitis.

BACKGROUND: Longitudinally extensive transverse myelitis (LETM) is a characteristic manifestation of neuromyelitis optica (NMO). However, not all patients with LETM are positive for aquaporin-4 (AQP4) antibodies. We evaluated the characteristics of idiopathic isolated LETM negative for AQP4 antibodies. METHODS: From the National Cancer Center registry of inflammatory diseases of the central nervous system, patients with LETM as an initial manifestation and follow-up for at least two years were enrolled. Their medical records and MRIs were reviewed retrospectively. AQP4 antibody was confirmed by three different validated methods at least three times. Cerebrospinal fluid (CSF) glial fibrillary acidic protein (GFAP) levels were measured to investigate astrocyte damage. RESULTS: Among 108 patients with first-ever LETM, 55 were positive for AQP4 antibodies (P-LETM) and 53 were consistently negative. Of them, seven were later diagnosed with seronegative NMO, and four were positive for MOG antibodies. The remaining 42 patients (N-LETM) showed several features distinct from P-LETM: male predominance, older age of onset, milder clinical presentation, spinal cord confinement and absence of combined autoimmunity. CSF GFAP levels were not increased in N-LETM but were markedly elevated in P-LETM. CONCLUSIONS: Idiopathic isolated N-LETM is not that rare among first-ever LETM, and has many features distinct from P-LETM where astrocytic damage is evident.

Transverse myelitis plus syndrome and acute disseminated encephalomyelitis plus syndrome: a case series of 5 children.

IMPORTANCE: Classically, transverse myelitis and acute disseminated encephalomyelitis are considered central nervous system demyelinating conditions. In both conditions, the spinal cord is involved to varying degrees, and there is a variety of presentations, usually involving some degree of progressive paralysis of the upper and/or lower extremities. Treatment usually consists of high-dose intravenous steroids in addition to plasma exchange and/or intravenous immunoglobulin. In some cases, immunosuppressive medications, such as intravenous cyclophosphamide, have been used with variable success. Cases with atypical features on examination, imaging, or with neurophysiological studies may be helpful in shedding light on the etiology and/or pathophysiology because many of these patients have permanent disabilities despite appropriate treatment. OBSERVATIONS: This case series presents 5 pediatric cases observed from 2009-2012 at our medical center, Children's Medical Center Dallas. These cases were notable because they provided evidence of autoimmune events affecting the central nervous system but with additional peripheral axonal pathology. CONCLUSIONS AND RELEVANCE: We describe these cases with respect to findings that suggest a variant of these conditions that have concomitant nerve-root involvement. These patients had worse outcomes than typical patients with transverse myelitis/acute disseminated encephalomyelitis, and these observations build on previous work by other investigators that highlighted persistent flaccid paralysis and electrophysiological evidence of axonal loss portending a poorer prognosis. Furthermore, these cases suggest a potential role for approaching how we classify subtypes of transverse myelitis and acute disseminated encephalomyelitis.

[Nosology and etiologies of acute longitudinally extensive transverse myelitis]. / Cadre nosologique et stratégie diagnostique de la myélite aiguë transverse longitudinalement étendue.

Acute transverse myelitis had many names and definitions, based primarily on clinical criteria. The role of MRI in the exploration of myelitis has increased recently after the individualization of neuromyelitis optica (NMO) in 2004. This approach has enabled clarification of the diagnostic and prognostic value of acute longitudinally extensive transverse myelitis (LETM), defined by an extensive T2 lesion affecting three vertebral segments in the sagittal plane. The limitations of this definition, the multiplicity of terms used to characterize it as well as the large number of etiologies associated with it led our group of experts to clarify its etiology and nosology. We conducted a national survey on this subject in order to propose a new definition of LETM. Additional first- and second-intention examinations were determined according to the clinical context. Infectious/para-infectious, inflammatory or paraneoplastic causes can thus be identified. To determine within a short time the cause of LETM is essential, since most of its causes are severe and require urgent treatment.

Aquaporin 4 IgG serostatus and outcome in recurrent longitudinally extensive transverse myelitis.

IMPORTANCE: Studies focused on recurrent longitudinally extensive transverse myelitis (rLETM) are lacking. OBJECTIVES: To determine the aquaporin 4 (AQP4) IgG detection rate using recombinant human APQ4-based assays in sequential serum specimens collected from patients with rLETM categorized as negative by first-generation tissue-based indirect immunofluorescence (IIF) assay and to define the clinical characteristics and motor disability outcomes in AQP4-IgG-positive rLETM. DESIGN, SETTING, AND PARTICIPANTS: A search of the Mayo Clinic computerized central diagnostic index (October 1, 2005, through November 30, 2011), cross-linked with the Neuroimmunology Laboratory database, identified 48 patients with rLETM, of whom 36 (75%) were positive and 12 (25%) negative for neuromyelitis optica (NMO) IgG (per IIF of serial serum specimens). Stored serum specimens from "seronegative" patients were retested with recombinant human AQP4-based assays, including enzyme-linked immunosorbent, transfected cell-based, and fluorescence-activated cell-sorting assays. Control patients included 140 AQP4-IgG-positive patients with NMO, of whom a subgroup of 20 initially presented with 2 attacks of transverse myelitis (rLETM-onset NMO). MAIN OUTCOMES AND MEASURES: AQP4-IgG serostatus, clinical characteristics, and Expanded Disability Status Scale score. RESULTS: Six patients with negative IIF results were reclassified as AQP4-IgG positive, yielding an overall AQP4-IgG seropositivity rate of 89%. Fluorescence-activated cell-sorting, cell-based, and enzyme-linked immunosorbent assays improved the detection rate to 89%, 85%, and 81%, respectively. The female to male ratio was 2:3 for AQP4-IgG-negative rLETM and 5:1 for AQP4-IgG-positive patients. The AQP4-IgG-positive patients with rLETM or rLETM-onset NMO were similar in age at onset, sex ratio, attack severity, relapse rate, and motor disability. From Kaplan-Meier analyses, 36% of AQP4-IgG-positive patients with rLETM are anticipated to need a cane to walk within 5 years after onset. For patients with rLETM-onset NMO, the median time from onset to first optic neuritis attack (54 months) was similar to the median disease duration for AQP4-IgG-positive patients with rLETM (59 months). The median number of attacks was 3 for AQP4-IgG-positive patients with rLETM (range, 2-22), and the first optic neuritis attack for those with rLETM-onset NMO followed a median of 3 myelitis attacks (range, 2-19). Immunosuppressant therapy reduced the relapse rate in both AQP4-IgG-positive and AQP4-IgG-negative patients with rLETM. CONCLUSIONS AND RELEVANCE: Recombinant antigen-based assays significantly increase AQP4-IgG detection in patients with rLETM, and AQP4-IgG-negative adults with rLETM are rare. Evolution to NMO can be anticipated in AQP4-IgG-positive patients. Early initiation of immunotherapy may result in a more favorable motor outcome.

Immune-mediated CNS diseases: a review on nosological classification and clinical features.

The immune-mediated diseases of the central nervous system (CNS) cover a wide range of clinical manifestations. Over the last years, considerable efforts have been made to establish a nosologic concept based upon distinctive pathophysiological characteristics of the single diseases. We describe the historically defined entities of immune-mediated diseases that primarily, but not exclusively, are affecting myelin structures. These include very rare entities as Schilder's, Balo's and Marburg's disease or the chronic and relapsing types of optic neuritis, for which evidence based paradigms still are virtually missing. In other, slightly more frequent diseases as neuromyelitis optica (NMO), advances in the concepts of specific biological features have been achieved and are beginning to transform into changes in clinical concepts. Acute disseminated encephalomyelitis (ADEM) and multiple sclerosis (MS) are by far the most frequent entities in this group and thus the only ones for which extensive empirical data on disease biology and evidence based clinical management strategies exist by now. For the most important entities, clinical features and therapeutic approaches are reviewed on the basis of current evidence. The results of basic science studies are assessed for their implications in nosological classification.

Clinically isolated acute transverse myelitis: prognostic features and incidence.

UNLABELLED: Demyelinating acute transverse myelitis may be the first presentation of multiple sclerosis or remain a clinically isolated syndrome. North Canterbury, New Zealand provides a well circumscribed population to study acute transverse myelitis. OBJECTIVE: to identify prognostic features, clinical outcomes and incidence of ATM in North Canterbury, New Zealand. All patients with acute transverse myelitis as a first neurological presentation diagnosed from January 2001 to December 2005 at a single institution providing all neurological care for North Canterbury were assessed for clinical data, MRI findings, cerebrospinal fluid results and clinical outcomes. CHAMPS, Barkhof/Tintore and Swanton criteria were applied to brain MRI. Sixty-one patients were identified with a mean duration of follow-up of 30 +/- 17 months. Fifty percent of patients with ATM with brain lesions by CHAMPS criteria converted to clinically definite multiple sclerosis. No patients with idiopathic acute transverse myelitis converted to clinically definite multiple sclerosis. There was a strong association with conversion to clinically definite multiple sclerosis and abnormal brain MRI by CHAMPS criteria (hazard ratio, 5.63; 1.83-17.3), Barkhof/Tintore criteria (hazard ratio, 6.43; 2.31-17.9) and Swanton criteria (hazard ratio, 4.53; 1.67-12.3). The age standardized annual incidence of acute transverse myelitis was 24.6 (18.2-31.1) per million, of definite and possible idiopathic acute transverse myelitis was 6.2 (2.9-9.6) per million, and of acute transverse myelitis with brain lesions was 4.7 (1.9-7.6) per million. Patients with idiopathic acute transverse myelitis are at low risk for conversion to clinically definite multiple sclerosis. Abnormal brain MRI by CHAMPS criteria is a sensitive predictor of conversion to clinically definite multiple sclerosis. The annual incidence of acute transverse multiple sclerosis in North Canterbury, New Zealand is significantly higher than previously reported.

Characteristics of acute transverse myelitis at Aga Khan University Hospital, Karachi.

OBJECTIVE: To determine the presenting features and etiological classification of acute transverse myelitis (ATM) at Aga Khan University Hospital, a tertiary care hospital in Pakistan. METHODS: Twenty consecutive patients of ATM (1996-2003) fulfilling a preset criterion were analyzed for demographic features, clinical presentation, laboratory investigations and neuro-imaging. RESULTS: Half of the patients were males and their median age was 29 years (range 6-73 years). Fever, paraparesis, quadri-paresis and bladder dysfunction were the most common presentations. Median score on disability rating scale (DRS) was twelve. Sixty percent of the patients were classified as Idiopathic-ATM while 30% and 10% as Para infectious associated-ATM and Multiple sclerosis associated-ATM respectively. CONCLUSION: Idiopathic acute transverse myelitis is the most common type of ATM in the studied population. Our data suggested that the severity of motor impairment is greater in our population than that reported in western literature which might hint to different genetic or environmental etiological factors involved in the pathogenesis of acute transverse myelitis.

Nosology of idiopathic transverse myelitis syndromes.

Several terms are now commonly used to describe various presentations of idiopathic myelitis, including acute transverse myelitis, acute partial transverse myelitis, and secondary myelitis. Ideally, a classification system would be able to encompass various presentations in a manner that not only assists in prognosis, but also in treatment decisions. Unfortunately, we are limited in our ability to accurately identify those patients who will progress to develop multiple sclerosis, Devic's syndrome, relapsing myelitis, or will remain monophasic. However, general principles are emerging that assist in prognosis based on the particular presenting features of any patient. We review the most recent criteria proposed for various forms of transverse myelitis and highlight the limitations of these classification schemes.

Proposed diagnostic criteria and nosology of acute transverse myelitis.

Acute transverse myelitis (ATM) is a focal inflammatory disorder of the spinal cord, resulting in motor, sensory, and autonomic dysfunction. A set of uniform diagnostic criteria and nosology for ATM is proposed to avoid the confusion that inevitably results when investigators use differing criteria. This will ensure a common language of classification, reduce diagnostic confusion, and lay the groundwork necessary for multicenter clinical trials. In addition, a framework is suggested for evaluation of individuals presenting with signs and symptoms of ATM. Best treatment often depends on a timely and accurate diagnosis. Because acute transverse myelopathies are relatively rare, delayed and incomplete work-ups often occur. Rapid and precise diagnosis will ensure not only that compressive lesions are detected and treated but also that idiopathic ATM is distinguished from ATM secondary to a known underlying disease. Identification of etiologies may suggest medical treatment, whereas no clearly established medical treatment currently exists for idiopathic ATM. Establishment of a diagnostic algorithm will likely lead to improved care, although it is recognized that the entire evaluation may not be performed for each patient.