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.

Fatigue in multiple sclerosis is closely related to sleep disorders: a polysomnographic cross-sectional study

BACKGROUND

Sleep disorders can cause tiredness. The relationship between sleep disorders and fatigue in patients with multiple sclerosis (MS) has not yet been investigated systematically.

OBJECTIVE

To investigate the relationship between fatigue and sleep disorders in patients with MS.

METHODS

Some 66 MS patients 20 to 66 years old were studied by overnight polysomnography. Using a cut-off point of 45 in the Modified Fatigue Impact Scale (MFIS), the entire cohort was stratified into a fatigued MS subgroup (n=26) and a non-fatigued MS subgroup (n=40).

RESULTS

Of the fatigued MS patients, 96% (n=25) were suffering from a relevant sleep disorder, along with 60% of the non-fatigued MS patients (n=24) (p=0.001). Sleep-related breathing disorders were more frequent in the fatigued MS patients (27%) than in the non-fatigued MS patients (2.5%). Significantly higher MFIS values were detected in all (fatigued and non-fatigued) patients with relevant sleep disorders (mean MFIS 42.8; SD 18.3) than in patients without relevant sleep disorders (mean MFIS 20.5; SD 17.0) (p<0.001). Suffering from a sleep disorder was associated with an increased risk of fatigue in MS (odds ratio: 18.5; 95% CI 1.6-208; p=0.018).

CONCLUSION

Our results demonstrate a clear and significant relationship between fatigue and sleep disorders.

ABC-transporter gene-polymorphisms are potential pharmacogenetic markers for mitoxantrone response in multiple sclerosis

Escalation therapy with mitoxantrone (MX) in highly active multiple sclerosis is limited by partially dose-dependent side-effects. Predictors of therapeutic response may result in individualized risk stratification and MX dosing. ATP-binding cassette-transporters ABCB1 and ABCG2 represent multi-drug resistance mechanisms involved in active cellular MX efflux. Here, we investigated the role of ABC-gene single nucleotide polymorphisms (SNPs) for clinical MX response, corroborated by experimental in vitro and in vivo data. Frequencies of ABCB1 2677G>T, 3435C>T and five ABCG2-SNPs were analysed in 832 multiple sclerosis patients (Germany, Spain) and 264 healthy donors. Using a flow-cytometry-based in vitro assay, MX efflux in leukocytes from individuals with variant alleles in both ABC-genes (designated genotype ABCB1/ABCG2-L(ow), 22.2% of patients) was 37.7% lower than from individuals homozygous for common alleles (ABCB1/ABCG2-H(igh), P < 0.05, 14.8% of patients), resulting in genotype-dependent MX accumulation and cell death. Addition of glucocorticosteroids (GCs) inhibited MX efflux in vitro. ABC-transporters were highly expressed in leukocyte subsets, glial and neuronal cells as well as myocardium, i.e. cells/tissues potentially affected by MX therapy. In vivo significance was further corroborated in experimental autoimmune encephalomyelitis in Abcg2(-/-) animals. Using a MX dose titrated to be ineffective in wild-type animals, disease course and histopathology in Abcg2(-/-) mice were strongly ameliorated. Retrospective clinical analysis in MX monotherapy patients (n = 155) used expanded disability status scale, relapse rate and multiple sclerosis functional composite as major outcome parameters. The clinical response rate [overall 121 of 155 patients (78.1%)] increased significantly with genotypes associated with decreasing ABCB1/ABCG2-function [ABCB1/ABCG2-H 15/24 (62.5%) responders, ABCB1/ABCG2-I(ntermediate) 78/98 (79.6%), ABCB1/ABCG2-L 28/33 (84.8%), exact Cochran-Armitage test P = 0.039]. The odds ratio for response was 1.9 (95% CI 1.0-3.5) with each increase in ABCB1/ABCG2 score (from ABCB1/ABCG2-H to -I-, and -I to -L). In 36 patients with severe cardiac or haematological side effects no statistically relevant difference in genotype frequency was observed. However, one patient with biopsy proven cardiomyopathy only after 24 mg/m2 MX exhibited a rare genotype with variant, partly homozygous alleles in 3 ABC-transporter genes. In conclusion, SNPs in ABC-transporter genes may serve as pharmacogenetic markers associated with clinical response to MX therapy in multiple sclerosis. Combined MX/GC-treatment warrants further investigation.

MR spectroscopy (MRS) and magnetisation transfer imaging (MTI), lesion load and clinical scores in early relapsing remitting multiple sclerosis: a combined cross-sectional and longitudinal study

The purpose of this study was to correlate magnetic resonance imaging (MRI)-based lesion load assessment with clinical disability in early relapsing remitting multiple sclerosis (RRMS). Seventeen untreated patients (ten women, seven men; mean age 33.0 +/- 7.9 years) with the initial diagnosis of RRMS were included for cross-sectional as well as longitudinal (24 months) clinical and MRI-based assessment in comparison with age-matched healthy controls. Conventional MR sequences, MR spectroscopy (MRS) and magnetisation transfer imaging (MTI) were performed at 1.5 T. Lesion number and volume, MRS and MTI measurements for lesions and normal appearing white matter (NAWM) were correlated to clinical scores [Expanded Disability Status Scale (EDSS), Multiple Sclerosis Functional Composite (MSFC)] for monitoring disease course after treatment initiation (interferon beta-1a). MTI and MRS detected changes [magnetisation transfer ratio (MTR), N-acetylaspartate (NAA)/creatine ratio] in NAWM over time. EDSS and lesional MTR increases correlated throughout the disease course. Average MTR of NAWM raised during the study (p < 0.05) and correlated to the MSFC score (r = 0.476, p < 0.001). At study termination, NAA/creatine ratio of NAWM correlated to the MSFC score (p < 0.05). MTI and MRS were useful for initial disease assessment in NAWM. MTI and MRS correlated with clinical scores, indicating potential for monitoring the disease course and gaining new insights into treatment-related effects.

Early mitoxantrone-induced cardiotoxicity in secondary progressive multiple sclerosis

Mitoxantrone is an anthracenedione antineoplastic agent approved as an escalating immunotherapy for multiple sclerosis. Owing to structural similarity with other anthracyclines, cardiotoxicity is a severe side effect of mitoxantrone. The risk of mitoxantrone-induced cardiotoxicity in patients with multiple sclerosis increases with cumulative doses >100 mg/m(2) body surface area (BSA). However, the effect of mitoxantrone on cardiac function in the early phase of treatment with cumulative doses <100 mg/m(2) BSA is unclear. The present report concerns four patients with a temporary and considerable decrease in left ventricular ejection fraction (LVEF) and with additional echocardiographic findings of diastolic dysfunction after only one or two doses of mitoxantrone. The risk of cardiotoxicity at low doses of mitoxantrone is highlighted.