J Kitley

Myelin-oligodendrocyte glycoprotein antibodies in adults with a neuromyelitis optica phenotype.

Objectives: To report an association of myelin-oligodendrocyte glycoprotein (MOG) antibodies with aquaporin-4 (AQP4) antibody–seronegative neuromyelitis optica (NMO) and neuromyelitis optica spectrum disorder (NMOSD) in adults. Methods: We describe the clinical and serologic features of 4 adult patients with an NMO/NMOSD phenotype who had antibodies to MOG. Results: Twenty-seven adult AQP4-seronegative NMO/NMOSD patients were tested for MOG antibodies. Four patients (3 male, 1 female) with severe optic neuritis and/or longitudinally extensive transverse myelitis were positive. All 4 made good recoveries with steroids or plasma exchange. Two patients experienced recurrence of symptoms when corticosteroids were withdrawn quickly but none have experienced further relapses over a mean follow-up of 12 months, although 3 patients remain on treatment. Imaging abnormalities resolved fully following clinical recovery and MOG antibody titers fell in all 4 patients. MOG antibodies were not found in 44 AQP4 antibody–positive NMO/NMOSD patients, 75 adult patients with multiple sclerosis, or 47 healthy individuals. Conclusions: MOG antibody–associated NMO/NMOSD could account for some cases thought previously to be AQP4-seronegative NMO/NMOSD. Our 4 patients appear to have more favorable clinical outcomes than those with typical AQP4 antibody–mediated disease. However, further studies of NMO/NMOSD and other demyelinating conditions are required to help clarify the diagnostic and prognostic relevance of MOG antibodies.

Prognostic factors and disease course in aquaporin-4 antibody-positive patients with neuromyelitis optica spectrum disorder from the United Kingdom and Japan

Neuromyelitis optica and neuromyelitis optica spectrum disorders have been recently associated with the disease-specific autoantibody aquaporin-4, thought to be pathogenic. Identifying this antibody has allowed the clinical phenotype to be broadened. It is clear that some patients with similar clinical features do not have this antibody and may have a different condition with different outcomes and prognosis. Previous clinical neuromyelitis optica and neuromyelitis optica spectrum disorder studies have included such patients. We investigated clinical outcomes and prognostic characteristics of 106 aquaporin-4 antibody-seropositive patients from the UK and Japan. We looked at predictors of disability outcomes, namely visual disability (permanent bilateral visual loss with visual acuity of <6/36 in the best eye), motor disability (permanent inability to walk further than 100 m unaided), wheelchair dependence and mortality. Data were collected largely retrospectively through review of case records. After median disease duration of 75 months, 18% had developed permanent bilateral visual disability, 34% permanent motor disability, 23% had become wheelchair dependent and 9% had died. Age at disease onset appeared to be an important predictor of disability type. Young-onset patients in the UK, but not the Japanese cohort, commonly presenting with optic neuritis, had a high risk of visual disability while older patients in both cohorts had a high risk of motor disability, regardless of their onset symptom. Genetic factors also appeared important. The UK cohort seemed to have more severe disease than the Japanese cohort, with more severe onset attacks, a higher relapse frequency and greater disability at follow-up, despite earlier immunosuppression. Moreover, within the UK cohort, there were important differences between ethnic groups, with Afro-Caribbean patients having a younger age at disease onset, more brain and multifocal attacks and higher likelihood of visual disability than Caucasian patients. Thus, age at disease onset and genetic factors are both likely to be important in determining clinical outcomes in aquaporin-4 disease. This has important implications for interpreting clinical neuromyelitis optica and neuromyelitis optica spectrum disorder studies, since clinical features and outcomes appear not to be generic across populations and may need to be tailored to individual groups. These factors need to be explored further in future prospective neuromyelitis optica and neuromyelitis optica spectrum disorder studies.

The differential diagnosis of longitudinally extensive transverse myelitis

Longitudinally extensive transverse myelitis refers to florid and widespread inflammation of the spinal cord causing T2 hyperintensity on spinal magnetic resonance imaging that is seen to extend over three or more vertebral segments. Whilst rare, longitudinally extensive transverse myelitis is clinically important as it can lead to catastrophic morbidity, and a group of these patients are at risk of further attacks. Early identification and establishment of the underlying aetiology is vital in order to initiate appropriate therapy and optimize outcomes. Whilst longitudinally extensive transverse myelitis is classically associated with neuromyelitis optica, there are many other causes. These include other inflammatory aetiologies, infection, malignancy and metabolic disturbance. Some of these are readily treatable. Laboratory and radiological investigations can help to differentiate these causes. Treatment of longitudinally extensive transverse myelitis hinges on distinguishing inflammatory and non-inflammatory aetiologies and identifying patients who are at high risk of a recurrent course.

Long-term efficacy, tolerability and retention rate of azathioprine in 103 aquaporin-4 antibody-positive neuromyelitis optica spectrum disorder patients: a multicentre retrospective observational study from the UK

Background: Azathioprine (AZA) is a common immunosuppressive drug used for relapse prevention in neuromyelitis optica (NMO). Objectives: The objective of this paper is to assess efficacy, tolerability and retention of AZA in a large NMO cohort. Methods: We conducted a retrospective review of medical records of 103 aquaporin-4 antibody-positive NMO and NMO spectrum disorder (NMOSD) patients treated with AZA. Results: This is the largest reported cohort of AQP4-Ab positive patients treated with AZA. Eighty-nine per cent (n = 92) had reduction in median annualised relapse rates from 1.5 (IQR 0.6–4.0) to 0 (IQR 0–0.27, p < 0.00005) with treatment. Sixty-one per cent (n = 63) remained relapse free at a median follow-up of 18 months. Neurological function improved or stabilised in 78%. At last follow-up, treatment was discontinued in 46% (n = 47). Of these, 62% (n = 29) were because of side effects, 19% (n = 9) because of death, 15% (n = 7) because of ongoing disease activity, and 2% (n = 1) because of pregnancy. Using Kaplan-Meyer curves, we estimate that 73%, 58%, 47% and 33% of patients will remain on AZA for longer than one, three, five and 10 years, respectively, after initiation of treatment. Conclusions: AZA is a modestly effective treatment for NMO. However, many patients discontinue AZA over time and this seems to reflect poor tolerability more than lack of efficacy.

Neurologic manifestations of the cryopyrin-associated periodic syndrome

Background: The cryopyrin-associated periodic syndrome (CAPS) is a rare but treatable hereditary autoinflammatory condition. Without treatment, one third of patients develop amyloidosis with consequent renal failure and death. CAPS encompasses 3 conditions: familial cold autoinflammatory syndrome, Muckle–Wells syndrome, and chronic infantile, neurologic, cutaneous, and articular syndrome. Neurologic complications are common in children with the chronic infantile, neurologic, cutaneous, and articular phenotype, but there are no previous published reports of neurologic features in adults with milder phenotypes. Methods: In this case series, we report in detail an adult case of CAPS and summarize the neurologic features seen in 12 other adults with genetically proven CAPS. These patients participated in a recent randomized study of canakinumab in CAPS and we used pretreatment data collected in this study. Results: Twelve of the 13 patients (92%) had headache, of whom 10 (77%) had features of migraine. Seven patients (54%) had sensorineural deafness. Nine patients (69%) reported myalgia. Six patients (46%) had papilledema and a further 2 (15%) had optic disc pallor. MRI brain scan was normal in all patients. Conclusion: CAPS is a rare but treatable condition that may be encountered by neurologists in adult clinical practice since it can present with headache, myalgia, papilledema, sensorineural deafness, and aseptic meningitis. Unrecognized and untreated, it can lead to significant morbidity and mortality from renal failure. Treatment with anti-interleukin-1 therapy leads to complete resolution of symptoms and should also prevent progression to amyloidosis and subsequent renal failure.

Pregnancy outcomes in aquaporin-4–positive neuromyelitis optica spectrum disorder

Objective: To investigate the association between neuromyelitis optica spectrum disorder (NMOSD) and pregnancy outcome. Methods: An international cohort of women with aquaporin-4 antibody–positive NMOSD and ≥1 pregnancy was studied retrospectively. Multivariate logistic regression was used to investigate whether pregnancy after NMOSD onset was associated with an increased risk of miscarriage (cohort of 40 women) or preeclampsia (cohort of 57 women). Results: Miscarriage rate was higher in pregnancies after NMOSD onset (42.9% [95% confidence interval 17.7%–71.1%] vs 7.04% [2.33%–15.7%]). Pregnancies conceived after, or up to 3 years before, NMOSD onset had an increased odds ratio of miscarriage (7.28 [1.03–51.6] and 11.6 [1.05–128], respectively), independent of maternal age or history of miscarriage. Pregnancies after, or up to 1 year before, NMOSD onset ending in miscarriage were associated with increased disease activity from 9 months before conception to the end of pregnancy, compared to viable pregnancies (mean annualized relapse rate 0.707 vs 0.100). The preeclampsia rate (11.5% [6.27%–18.9%]) was significantly higher than reported in population studies. The odds of preeclampsia were greater in women with multiple other autoimmune disorders or miscarriage in the most recent previous pregnancy, but NMOSD onset was not a risk factor. Conclusions: Pregnancy after NMOSD onset is an independent risk factor for miscarriage, and pregnancies conceived at times of high disease activity may be at increased risk of miscarriage. Women who develop NMOSD and have multiple other autoimmune disorders have greater odds of preeclampsia, independent of NMOSD onset timing.

Characterization of neuromyelitis optica and neuromyelitis optica spectrum disorder patients with a late onset

Background: Few data are available for patients with a late onset (≥ 50 years) of neuromyelitis optica (LONMO) or neuromyelitis optica spectrum disease (LONMOSD), defined by an optic neuritis/longitudinally extensive transverse myelitis with aquaporin-4 antibodies (AQP4-Ab). Objective: To characterize LONMO and LONMOSD, and to analyze their predictive factors of disability and death. Methods: We identified 430 patients from four cohorts of NMO/NMOSD in France, Germany, Turkey and UK. We extracted the late onset patients and analyzed them for predictive factors of disability and death, using the Cox proportional model. Results: We followed up on 63 patients with LONMO and 45 with LONMOSD during a mean of 4.6 years. This LONMO/LONMOSD cohort was mainly of Caucasian origin (93%), women (80%), seropositive for AQP4-Ab (85%) and from 50 to 82.5 years of age at onset. No progressive course was noted. At last follow-up, the median Expanded Disability Status Scale (EDSS) scores were 5.5 and 6 in the LONMO and LONMOSD groups, respectively. Outcome was mainly characterized by motor disability and relatively good visual function. At last follow-up, 14 patients had died, including seven (50%) due to acute myelitis and six (43%) because of opportunistic infections. The EDSS 4 score was independently predicted by an older age at onset, as a continuous variable after 50 years of age. Death was predicted by two independent factors: an older age at onset and a high annualized relapse rate. Conclusion: LONMO/LONMOSD is particularly severe, with a high rate of motor impairment and death.

Detrimental role of granulocyte-colony stimulating factor in neuromyelitis optica: clinical case and histological evidence

In a recent study, administration of granulocyte colony stimulating factor (G-CSF) increased neuromyelitis optica (NMO) lesions in mice. Here we report a patient whose first episode of NMO may have been exacerbated by inadvertent administration of G-CSF. Histological examination of brain and spinal cord samples from three other NMO patients revealed markedly increased expression of G-CSF in neurons located in and around the lesions, with little or no expression in multiple sclerosis lesions or normal white matter. Taken together, these cases support a detrimental role for G-CSF in NMO pathogenesis.

Aquaporin-4 antibody isoform binding specificities do not explain clinical variations in NMO.

Objective: To assess the clinical relevance of the differential binding of antibodies against the 2 main aquaporin-4 (AQP4) isoforms in neuromyelitis optica (NMO) patient sera using stably transfected human embryonic kidney cells. Methods: Flow cytometry of human embryonic kidney cells stably transfected with either M23 or M1 AQP4 was used to measure antibody endpoint titers in 52 remission samples and 26 relapse samples from 34 patients with clinically well-characterized AQP4 antibody–positive NMO/NMO spectrum disorder. Results: The AQP4 M23 (40–61,440) and AQP4 M1 (<20–20,480) titers varied widely between patients, as did the M23:M1 antibody ratio (1–192). In 76 of 78 samples, binding to M23 was higher than binding to M1, including during relapses and remissions (p < 0.0001), and the M23:M1 ratio was relatively constant within an individual patient. Titers usually fell after immunosuppression, but the titers at which relapses occurred varied markedly; no threshold level for relapses could be identified, and relapses could occur without a rise in titers. Relapse severity did not correlate with M23 or M1 antibody titers, although there was a correlation between the earliest M23 titers and annualized relapse rates. The M23:M1 ratio and absolute M23 and M1 titers did not relate to age at disease onset, ethnicity, disease severity, phenotype, or relapses at different anatomical sites. Conclusion: Relative AQP4 antibody binding to M23 and M1 isoforms differs between patients but there is no consistent association between these differences and clinical characteristics of disease. Nevertheless, the M23 isoform provided a slightly more sensitive substrate for AQP4-antibody assays, particularly for follow-up studies.

Time to next relapse as a primary endpoint in neuromyelitis optica clinical trials

Neuromyelitis optica (NMO) and its spectrum disorder (NMOSD) is a severe autoimmune inflammatory disorder of the central nervous system, with recurrent attacks mainly focused on the optic nerves and spinal cord. Untreated, it has a high morbidity and mortality. Serum aquaporin-4 (AQP4) antibodies are present in the majority of patients, are recognised as pathogenic and are a predictor of further relapses.1 Most specialists treat AQP4 antibody-positive patients early and aggressively with immunosuppression to prevent further attacks. There have been no randomised trials in NMO, but prednisolone, azathioprine, mycophenolate mofetil, methotrexate and rituximab are among the therapies currently used and appear to have comparable efficacy.2 ,3 Because of the potentially devastating nature of NMO relapses, many clinicians would consider a single relapse on treatment to represent treatment failure and an indication to alter therapy, particularly if the relapse is severe and the therapy has had adequate time to work. This alteration can take the form of an increase in dosage of current treatment or a switch to an alternative agent. There is an urgent need to identify the most effective treatment regimens, particularly because there are many novel therapeutic candidates being developed, including those which act on the antibody-producing or complement pathways, and an AQP4 monoclonal antibody blocker.4 Current NMO study designs under discussion vary, with some regulatory authorities requesting placebo comparator arms but others accepting standard treatments (azathioprine or alternative plus low dose oral steroids)3 as comparators either as add-on or …