Clinical, serological and genetic predictors of response to immunotherapy in anti-IgLON5 disease.

Anti-IgLON5 disease is a newly defined clinical entity characterized by a progressive course with high disability and mortality rate. While precise pathogenetic mechanisms remain unclear, features characteristic of both autoimmune and neurodegenerative diseases were reported. Data on immunotherapy are limited, and its efficacy remains controversial. In this study, we retrospectively investigated an anti-IgLON5 disease cohort with special focus on clinical, serological and genetic predictors of the immunotherapy response and long-term outcome. Patients were recruited from the GENERATE (German Network for Research on Autoimmune Encephalitis) registry. Along with clinical parameters, anti-IgLON5 immunoglobulin (Ig)G in serum and CSF, anti-IgLON5 IgG1-4, IgA and IgM in serum, neurofilament light chain and glial fibrillary acidic protein in serum as well as human leukocyte antigen-genotypes were determined. We identified 53 patients (symptom onset 63.8 ± 10.3 years, female:male 1:1.5). The most frequent initial clinical presentations were bulbar syndrome, hyperkinetic syndrome or isolated sleep disorder [at least one symptom present in 38% (20/53)]. At the time of diagnosis, the majority of patients had a generalized multi-systemic phenotype; nevertheless, 21% (11/53) still had an isolated brainstem syndrome and/or a characteristic sleep disorder only. About one third of patients [28% (15/53)] reported subacute disease onset and 51% (27/53) relapse-like exacerbations during the disease course. Inflammatory CSF changes were evident in 37% (19/51) and increased blood-CSF-barrier permeability in 46% (21/46). CSF cell count significantly decreased, while serum anti-IgLON5 IgG titre increased with disease duration. The presence of human leukocyte antigen-DRB1*10:01 [55% (24/44)] was associated with higher serum anti-IgLON5 IgG titres. Neurofilament light chain and glial fibrillary acidic protein in serum were substantially increased (71.1 ± 103.9 pg/ml and 126.7 ± 73.3 pg/ml, respectively). First-line immunotherapy of relapse-like acute-to-subacute exacerbation episodes resulted in improvement in 41% (11/27) of patients and early initiation within the first 6 weeks was a predictor for therapy response. Sixty-eight per cent (36/53) of patients were treated with long-term immunotherapy and 75% (27/36) of these experienced no further disease progression (observation period of 20.2 ± 15.4 months). Long-term immunotherapy initiation during the first year after onset and low pre-treatment neurofilament light chain were significant predictors for a better outcome. In conclusion, subacute disease onset and early inflammatory CSF changes support the primary role of autoimmune mechanisms at least at initial stages of anti-IgLON5 disease. Early immunotherapy, prior to advanced neurodegeneration, is associated with a better long-term clinical outcome. Low serum neurofilament light chain at treatment initiation may serve as a potential biomarker of the immunotherapy response.

Prognostic value of free light chains lambda and kappa in early multiple sclerosis.

BACKGROUND: Cerebrospinal fluid (CSF) immunoglobulin free light chains (FLC) have been suggested as quantitative alternative to oligoclonal bands (OCB) in the diagnosis of multiple sclerosis (MS). However, little is known on their role in predicting clinical and paraclinical disease progression, particularly in early stages. OBJECTIVE: To assess the prognostic value of FLC in OCB-positive patients with clinically isolated syndrome (CIS) suggestive of MS and early MS. METHODS: We determined FLC kappa (KFLC) and lambda (LFLC) in CSF and serum by nephelometry in 61 patients (CIS ( n = 48), relapsing-remitting multiple sclerosis ( n = 13)) and 60 non-inflammatory neurological controls. Median clinical follow-up time in CIS was 4.8 years (interquartile range (IQR), 1.5-6.5 years). Patients underwent 3T magnetic resonance imaging (MRI) at baseline and follow-up (median time interval, 2.2 years; IQR, 1.0-3.7 years) to determine T2 lesion load (T2LL) and percent brain volume change (PBVC). RESULTS: CSF FLC were significantly increased in CIS/MS compared to controls (all p < 0.001). A lower KFLC/LFLC CSF ratio was associated with CIS-clinically definite multiple sclerosis (CDMS) conversion (hazard ratio (HR) = 2.89; 95% confidence interval (CI) = 1.17-7.14; p < 0.05). No correlations were found for FLC variables with T2LL or PBVC. CONCLUSION: Our study confirms increased intrathecal synthesis of FLC in CIS/MS which supports their diagnostic contribution. The KFLC/LFLC CSF ratio appears to have a prognostic value in CIS beyond OCB.

Susac's syndrome: clinical course and epidemiology in a Central European population.

OBJECTIVE: Susac's syndrome is characterized by inflammation and occlusion of pre-capillary arterioles with the clinical triad of branch retinal artery occlusion (BRAO), encephalopathy and hearing loss. No epidemiological data are available for the disease. METHODS: All neurology departments in Austria were addressed to report adult patients who were on immunosuppressive treatment for a diagnosis of Susac's syndrome between 1 August 2010 and 1 August 2015. Clinical course, treatment regimens, period and point prevalence rates, and annual incidence of Susac's syndrome in Austria in people over 19 years of age are reported. RESULTS: Ten patients with Susac's syndrome were identified, and eight of them were newly diagnosed within the five-year timeframe. Minimum five-year period prevalence of the disease is 0.148/100,000 (95% confidence interval (CI) 0.071-0.272), annual incidence is 0.024/100,000 (95% CI 0.010-0.047). Minimum point prevalence rates varied from 0.030/100,000 (95% CI 0.004-0.108) to 0.088/100,000 (95% CI 0.032-0.192). Of all 10 patients, 8 showed typical callosal or internal capsule magnetic resonance imaging lesions at first presentation, 7 presented with BRAO and 5 had hearing loss or tinnitus at the beginning of the disease. Four patients developed the complete clinical triad of Susac's syndrome during the observation period. CONCLUSIONS: We provide for the first time population-based data about the clinical course, prevalence and incidence of Susac's syndrome.

Characterization of the binding pattern of human aquaporin-4 autoantibodies in patients with neuromyelitis optica spectrum disorders.

BACKGROUND: The discovery of a highly specific antibody against the aquaporin-4 (AQP4) water channel (AQP4-IgG) unified the spectrum of neuromyelitis optica spectrum disorders (NMOSD), which are considered to be antibody-mediated autoimmune diseases. The AQP4 water channel is located on astrocytic end-feet processes and consists of six transmembrane helical domains forming three extracellular loops A, C, and E in which defined amino acids were already proven to be critical for AQP4-IgG binding. However, the clinical relevance of these findings is unclear. Therefore, we have characterized the epitope specificity of AQP4-IgG-positive NMOSD patients. METHODS: We established a cell-based flow cytometry assay for the quantitative detection of AQP4-IgG-positive serum samples. Human embryonic kidney (HEK) cells were transiently transfected with an EmGFP-tagged AQP4-M23, AQP4-M1, or six AQP4-M23 extracellular loop mutants including two mutations in loop A (serial AA substitution, insertion of a myc-tag), two in loop C (N153Q, insertion of a myc-tag), and two in loop E (H230G, insertion of a myc-tag). Fourty-seven baseline and 49 follow-up serum samples and six paired cerebrospinal fluid (CSF) baseline samples of 47 AQP4-IgG-positive Austrian NMOSD patients were then tested for their binding capability to AQP4-M1 and AQP4-M23 isoforms and these six extracellular loop mutants. RESULTS: Overall, we could identify two broad patterns of antibody recognition based on differential sensitivity to mutations in extracellular loop A. Pattern A was characterized by reduced binding to the two mutations in loop A, whereas pattern B had only partial or no reduced binding to these mutations. These two patterns were not associated with significant differences in demographic and clinical parameters or serum titers in this retrospective study. Interestingly, we found a change of AQP4-IgG epitope recognition pattern in seven of 20 NMOSD patients with available follow-up samples. Moreover, we found different binding patterns in five of six paired CSF versus serum samples, with a predominance of pattern A in CSF. CONCLUSIONS: Our study demonstrates that AQP4-IgG in sera of NMOSD patients show distinct patterns of antibody recognition. The clinical and diagnostic relevance of these findings have to be addressed in prospective studies.

Myocardial infarction as a complication in acute stroke: results from the austrian stroke unit registry.

BACKGROUND: Patients with transient ischemic attack (TIA) and stroke have an increased risk for subsequent cardiac events including myocardial infarction (MI), which might be associated with a worse clinical outcome. Rapid identification of stroke patients at higher risk for MI might foster intensified cardiac monitoring or certain therapeutic strategies. However, information regarding acute MI as a complication of stroke in the very acute phase is limited. Moreover, there are no systematic data on the occurrence of MI following intracerebral hematoma. We thus aimed to assess the frequency, clinical characteristics and short-term outcome of patients suffering from acute MI in the stroke unit setting. METHODS: We analyzed 46,603 patients from 32 Austrian stroke units enrolled in the prospective Austrian Stroke Unit Registry because of TIA/acute stroke over a 6-year period (January 1, 2007 to January 13, 2013). A total of 41,619 patients (89.3%) had been treated for TIA/ischemic stroke and 4,984 (10.7%) for primary intracerebral hemorrhage (ICH). Acute MI was defined according to clinical evaluation, ECG findings and laboratory assessments. Patients with evidence for MI preceding the cerebrovascular event were not considered. RESULTS: Overall, 421 patients (1%) with TIA/ischemic stroke and 17 patients (0.3%) with ICH suffered from MI during stroke unit treatment for a median duration of 3 days. Patients with TIA/ischemic stroke and MI were significantly older, clinically more severely affected and had more frequently vascular risk factors, atrial fibrillation and previous MI. Total anterior circulation and left hemispheric stroke syndromes were more often observed in MI patients. Patients with MI not only suffered from worse short-term outcome including a higher mortality (14.5 vs. 2%; p < 0.001) at stroke unit discharge, but also acquired more stroke complications like progressive stroke and pneumonia. Multivariate analyses identified previous MI and stroke severity at admission (according to the National Institutes of Health and Stroke Scale score) as factors independently associated with the occurrence of MI on the stroke unit. CONCLUSIONS: While quite rare in the acute phase after stroke, MI is associated with a poor short-term outcome including a higher mortality. Patients with previous MI and severe stroke syndromes appear to be at particular risk for MI as an early complication in the stroke unit setting. Further studies are needed to determine whether increased vigilance and prolonged (cardiac) monitoring or certain therapeutic approaches could improve the outcome in these high-risk patients.

Long-term outcome of natalizumab-associated progressive multifocal leukoencephalopathy in Austria: a nationwide retrospective study.

BACKGROUND/OBJECTIVE: The use of natalizumab (NAT) in multiple sclerosis (MS) may be complicated by progressive multifocal leukoencephalopathy (PML), a rare and life-threatening opportunistic brain infection. We aimed to analyze the course of MS after PML recovery together with the long-term outcome of NAT-associated PML (NAT-PML) in Austria. METHODS: Retrospective study based on identification of cases in the nationwide Austrian MS treatment registry (AMSTR) and MS centers with review of patient records. The expanded disability status scale (EDSS) was used to measure neurological disability and outcome. RESULTS: As of December 2022, we identified 15 NAT-PML cases in Austria; only 20% occurred after 2016, when increased vigilance commenced. Two patients did not survive acute PML, and an additional patient died five years later, yielding a mortality rate of 20%. Seizures occurred exclusively in patients with pronounced EDSS increase. Gadolinium (Gd)-enhancement on brain magnetic resonance imaging (MRI) on PML suspicion was associated with minor changes of post-PML neurological disability. Long-term follow-up of up to 132 months (median 76 months) was available in 11/15. The overall median EDSS increased from 3.5 at pre-PML to 6.5 at the last assessment. Regarding inflammatory MS-related disease activity during the observation period, one single individual experienced an MS relapse and another patient had two Gd-enhancing brain lesions. Three patients converted to progressive MS within three years from PML and the EDSS further increased in 6/11. CONCLUSIONS: The number of NAT-PML cases is decreasing over time. While many patients accumulated severe persistent neurological deficits compared to pre-PML, inflammatory MS-related disease activity after PML recovery was rare.

HLA dependency and possible clinical relevance of intrathecally synthesized anti-IgLON5 IgG4 in anti-IgLON5 disease.

Background: Anti-IgLON5 disease is a rare chronic autoimmune disorder characterized by IgLON5 autoantibodies predominantly of the IgG4 subclass. Distinct pathogenic effects were described for anti-IgLON5 IgG1 and IgG4, however, with uncertain clinical relevance. Methods: IgLON5-specific IgG1-4 levels were measured in 46 sera and 20 cerebrospinal fluid (CSF) samples from 13 HLA-subtyped anti-IgLON5 disease patients (six females, seven males) using flow cytometry. Intervals between two consecutive serum or CSF samplings (31 and 10 intervals, respectively) were categorized with regard to the immunomodulatory treatment active at the end of the interval, changes of anti-IgLON5 IgG1 and IgG4 levels, and disease severity. Intrathecal anti-IgLON5 IgG4 synthesis (IS) was assessed using a quantitative method. Results: The median age at onset was 66 years (range: 54-75), disease duration 10 years (range: 15-156 months), and follow-up 25 months (range: 0-83). IgLON5-specific IgG4 predominance was observed in 38 of 46 (83%) serum and 11 of 20 (55%) CSF samples. Anti-IgLON5 IgG4 levels prior clinical improvement in CSF but not serum were significantly lower than in those prior stable/progressive disease. Compared to IgLON5 IgG4 levels in serum, CSF levels in HLA-DRB1*10:01 carriers were significantly higher than in non-carriers. Indeed, IgLON5-specific IgG4 IS was demonstrated not only in four of five HLA-DRB1*10:01 carriers but also in one non-carrier. Immunotherapy was associated with decreased anti-IgGLON5 IgG serum levels. In CSF, lower anti-IgLON5 IgG was associated with immunosuppressive treatments used in combination, that is, corticosteroids and/or azathioprine plus intravenous immunoglobulins or rituximab. Conclusion: Our findings might indicate that CSF IgLON5-specific IgG4 is frequently produced intrathecally, especially in HLA-DRB1*10:01 carriers. Intrathecally produced IgG4 may be clinically relevant. While many immunotherapies reduce serum IgLON5 IgG levels, more intense immunotherapies induce clinical improvement and may be able to target intrathecally produced anti-IgLON5 IgG. Further studies need to confirm whether anti-IgLON5 IgG4 IS is a suitable prognostic and predictive biomarker in anti-IgLON5 disease.

Different pain phenotypes are associated with anti-Caspr2 autoantibodies.

Autoantibodies against contactin-associated protein 2 (Caspr2) not only induce limbic autoimmune encephalitis but are also associated with pain conditions. Here, we analyzed clinical data on pain in a large cohort of patients included into the German Network for Research in Autoimmune Encephalitis. Out of 102 patients in our cohort, pain was a frequent symptom (36% of all patients), often severe (63.6% of the patients with pain) and/or even the major symptom (55.6% of the patients with pain). Pain phenotypes differed between patients. Cluster analysis revealed two major phenotypes including mostly distal-symmetric burning pain and widespread pain with myalgia and cramps. Almost all patients had IgG4 autoantibodies and some additional IgG1, 2, and/or 3 autoantibodies, but IgG subclasses, titers, and presence or absence of intrathecal synthesis were not associated with the occurrence of pain. However, certain pre-existing risk factors for chronic pain like diabetes mellitus, peripheral neuropathy, or preexisting chronic back pain tended to occur more frequently in patients with anti-Caspr2 autoantibodies and pain. Our data show that pain is a relevant symptom in patients with anti-Caspr2 autoantibodies and support the idea of decreased algesic thresholds leading to pain. Testing for anti-Caspr2 autoantibodies needs to be considered in patients with various pain phenotypes.

Oxidative stress and apoptosis in a pig model of brain death (BD) and living donation (LD).

BACKGROUND: As organ shortage is increasing, the acceptance of marginal donors increases, which might result in poor organ function and patient survival. Mostly, organ damage is caused during brain death (BD), cold ischemic time (CIT) or after reperfusion due to oxidative stress or the induction of apoptosis. The aim of this study was to study a panel of genes involved in oxidative stress and apoptosis and compare these findings with immunohistochemistry from a BD and living donation (LD) pig model and after cold ischemia time (CIT). METHODS: BD was induced in pigs; after 12 h organ retrieval was performed; heart, liver and kidney tissue specimens were collected in the BD (n = 6) and in a LD model (n = 6). PCR analysis for NFKB1, GSS, SOD2, PPAR-alpha, OXSR1, BAX, BCL2L1, and HSP 70.2 was performed and immunohistochemistry used to show apoptosis and nitrosative stress induced cell damage. RESULTS: In heart tissue of BD BAX, BCL2L1 and HSP 70.2 increased significantly after CIT. Only SOD2 was over-expressed after CIT in BD liver tissue. In kidney tissue, BCL2L1, NFKB, OXSR1, SOD2 and HSP 70.2 expression was significantly elevated in LD. Immunohistochemistry showed a significant increase in activated Caspase 3 and nitrotyrosine positive cells after CIT in BD in liver and in kidney tissue but not in heart tissue. CONCLUSION: The up-regulation of protective and apoptotic genes seems to be divergent in the different organs in the BD and LD setting; however, immunohistochemistry revealed more apoptotic and nitrotyrosine positive cells in the BD setting in liver and kidney tissue whereas in heart tissue both BD and LD showed an increase.

Energy status of pig donor organs after ischemia is independent of donor type.

BACKGROUND: Literature is controversial whether organs from living donors have a better graft function than brain dead (BD) and non-heart-beating donor organs. Success of transplantation has been correlated with high-energy phosphate (HEP) contents of the graft. METHODS: HEP contents in heart, liver, kidney, and pancreas from living, BD, and donation after cardiac death in a pig model (n=6 per donor type) were evaluated systematically. BD was induced under general anesthesia by inflating a balloon in the epidural space. Ten hours after confirmation, organs were retrieved. Cardiac arrest was induced by 9V direct current. After 10min of ventricular fibrillation without cardiac output, mechanical and medical reanimation was performed for 30min before organ retrieval. In living donors, organs were explanted immediately. Freeze-clamped biopsies were taken before perfusion with Celsior solution (heart) or University of Wisconsin solution (abdominal organs) in BD and living donors or with Histidine-Tryptophan-Ketoglutaric solution (all organs) in non-heart-beating donors, after perfusion, and after cold ischemia (4h for heart, 6h for liver and pancreas, and 12h for kidney). HEPs (adenosine triphosphate, adenosine diphosphate, adenosine monophosphate, and phosphocreatine), xanthine, and hypoxanthine were measured by high-performance liquid chromatography. Energy charge and adenosine triphosphate-to-adenosine diphosphate ratio were calculated. RESULTS: After ischemia, organs from different donor types showed no difference in energy status. In all organs, a decrease of HEP and an increase in hypoxanthine contents were observed during perfusion and ischemia, irrespective of the donor type. CONCLUSION: Organs from BD or non-heart-beating donors do not differ from living donor organs in their energy status after average tolerable ischemia.

Anti-CD20 treatment and neutrophil function in central nervous system demyelinating diseases.

INTRODUCTION: A contribution of neutrophil granulocytes to the pathogenesis of multiple sclerosis (MS) and neuromyelitis optica spectrum disorders (NMOSD) is recognized. Anti-CD20 treatments applied in these diseases are associated with infectious complications and neutropenia. No data is available about functional characteristics of neutrophils obtained from patients with anti-CD20 treatments. METHODS: In neutrophils isolated from 13 patients with anti-CD20 treatment (9 MS, 4 NMOSD), 11 patients without anti-CD20 treatment (9 MS, 2 NMOSD) and 5 healthy controls, we analyzed chemotaxis, production of reactive oxygen species (ROS), phagocytosis, and formation of neutrophil extracellular traps (NET) in vitro. RESULTS: Chemotaxis and ROS production were found unchanged between patients with and without anti-CD20 treatment or between patients and healthy controls. We found a higher proportion of non-phagocytosing cells in patients without anti-CD20 treatment compared to patients with anti-CD20 treatment and healthy controls. As compared to healthy controls, a higher proportion of neutrophils from patients without anti-CD20 treatments underwent NET formation, either unstimulated or stimulated with phorbol 12-myristate 3-acetate for 3 h. In about half of patients with anti-CD20 treatment (n = 7), NET formation of unstimulated neutrophils occurred already within 20 min of incubation. This was not observed in patients without anti-CD20 treatment and healthy controls. CONCLUSION: Anti-CD20 treatment in MS and NMOSD patients does not alter chemotaxis and ROS production of neutrophils in vitro but might restore their impaired phagocytosis in these diseases. Our study reveals a predisposition to early NET formation in vitro of neutrophils obtained from patients with anti-CD20 treatment. This may contribute to associated risks of neutropenia and infections.

Altered cellular immune response to vaccination against SARS-CoV-2 in patients suffering from autoimmunity with B-cell depleting therapy.

B-cell depleting therapies result in diminished humoral immunity following vaccination against COVID-19, but our understanding on the impact on cellular immune responses is limited. Here, we performed a detailed analysis of cellular immunity following mRNA vaccination in patients receiving B-cell depleting therapy using ELISpot assay and flow cytometry. Anti-SARS-CoV-2 spike receptor-binding domain antibody assays were performed to elucidate B-cell responses. To complement our cellular analysis, we performed immunophenotyping for T- and B-cell subsets. We show that SARS-CoV-2 vaccination using mRNA vaccines elicits cellular T-cell responses in patients under B-cell depleting therapy. Some facets of this immune response including TNFα production of CD4+ T-cells and granzyme B production of CD8+ T-cells, however, are distinctly diminished in these patients. Consequently, it appears that the finely coordinated process of T-cell activation with a uniform involvement of CD4+ and CD8+ T-cells as seen in HCs is disturbed in autoimmune patients. In addition, we observed that immune cell composition does impact cellular immunity as well as sustainability of anti-spike antibody titers. Our data suggest disturbed cellular immunity following mRNA vaccination in patients treated with B-cell depleting therapy. Immune cell composition may be an important determinant for vaccination efficacy.

A 10min "no-touch" time - is it enough in DCD? A DCD animal study.

Donation after cardiac death (DCD) is under investigation because of the lack of human donor organs. Required times of cardiac arrest vary between 75s and 27min until the declaration of the patients' death worldwide. The aim of this study was to investigate brain death in pigs after different times of cardiac arrest with subsequent cardiopulmonary resuscitation (CPR) as a DCD paradigm. DCD was simulated in 20 pigs after direct electrical induction of ventricular fibrillation. The "no-touch" time varied from 2min up to 10min; then 30min of CPR were performed. Brain death was determined by established clinical and electrophysiological criteria. In all animals with cardiac arrest of at least 6min, a persistent loss of brainstem reflexes and no reappearance of bioelectric brain activity occurred. Reappearance of EEG activity was found until 4.5min of cardiac arrest and subsequent CPR. Brainstem reflexes were detectable until 5min of cardiac arrest and subsequent CPR. According to our experiments, the suggestion of 10min of cardiac arrest being equivalent to brain death exceeds the minimum time after which clinical and electrophysiological criteria of brain death are fulfilled. Therefore shorter "no-touch" times might be ethically acceptable to reduce warm ischemia time.

Spontaneous spinal cord infarction in Austria: a two-center comparative study.

Background: Spinal cord infarction (SCI) is a neurological emergency associated with high rates of persistent neurological deficits. Knowledge about this rare but potentially treatable condition needs to be expanded. Objective: To describe the characteristics of spontaneous SCI in a large retrospective series of patients treated at two tertiary care centers in Austria. Methods: We performed a descriptive and comparative analysis of spontaneous SCI treated at the University Hospitals of Salzburg and Graz between the years 2000 and 2020. The analysis included pre- and in-hospital procedures, clinical presentation, etiology, diagnostic certainty, reperfusion therapy, and functional outcome at discharge. Results: We identified 88 cases, 61% were ascertained in the second half of the study period. The median age was 65.5 years [interquartile range (IQR) = 56-74], 51.1% were women. Anterior spinal artery infarction was the predominant syndrome (82.9%). Demographics, vascular comorbidities, and clinical presentation did not differ between the centers. The most frequent etiology and level of diagnostic certainty were distinct, with atherosclerosis (50%) and definite SCI (42%), and unknown (52.5%) and probable SCI (60%) as front runners in Salzburg and Graz, respectively. Patients arrived after a median of 258.5 min (IQR = 110-528) at the emergency room. The first magnetic resonance imaging (MRI) of the spinal cord was performed after a median of 148 min (IQR = 90-312) from admission and was diagnostic for SCI in 45%. Two patients received intravenous thrombolysis (2.2%). The outcome was poor in 37/77 (48%). Conclusion: Demographics, clinical syndromes, and quality benchmarks for spontaneous SCI were consistent at two Austrian tertiary care centers. Our findings provide the foundation for establishing standards for pre- and in-hospital care to improve outcomes.

Evidence for an Intrathecal Immunoglobulin Synthesis by Kappa Free Light Chains in Neurological Patients with an Isolated Band in Isoelectric Focusing.

The gold standard for detecting intrathecal immunoglobulin synthesis is the determination of the oligoclonal band (OCB) in the cerebrospinal fluid (CSF) using isoelectric focusing (IEF). Controversy still exists regarding the significance of an isolated band in the CSF. A highly promising alternative method for the assessment of intrathecal inflammation is the quantification of kappa free light chains (k-FLC). Our aim was to evaluate the clinical significance of quantitative k-FLC in patients with an isolated band in the CSF. Using the Human Kappa Freelite Mx Kit on a turbidimetric Optilite®, we quantified the k-FLCs in paired CSF and serum samples in 47 patients with a single band in IEF. We classified patients into 27× inflammatory neurological disorders (IND), 2× peripheral inflammatory neurological disorders (PIND), 9× non-inflammatory neurological disorders (NIND) and 9× symptomatic controls (SC) based on their medical diagnosis. k-FLC were below the lower measurement limit of the analyser (LML) in all SC and PIND, as well as in 8 out of 9 NIND and 11 IND. Only 1 NIND and 16 IND were above the LML, and of these, only 14 IND were above the upper discrimination limit (Qlim). A neuroinflammatory nature of the diseases can be indicated in many cases by positive k-FLC in patients with an isolated band in IEF. The measurement of k-FLC can support the diagnosis of neurological diseases if they are included in the routine work-up.

Variants at APOE influence risk of deep and lobar intracerebral hemorrhage.

OBJECTIVE: Prior studies investigating the association between APOE alleles ε2/ε4 and risk of intracerebral hemorrhage (ICH) have been inconsistent and limited to small sample sizes, and did not account for confounding by population stratification or determine which genetic risk model was best applied. METHODS: We performed a large-scale genetic association study of 2189 ICH cases and 4041 controls from 7 cohorts, which were analyzed using additive models for ε2 and ε4. Results were subsequently meta-analyzed using a random effects model. A proportion of the individuals (322 cases, 357 controls) had available genome-wide data to adjust for population stratification. RESULTS: Alleles ε2 and ε4 were associated with lobar ICH at genome-wide significance levels (odds ratio [OR] = 1.82, 95% confidence interval [CI] = 1.50-2.23, p = 6.6 × 10(-10); and OR = 2.20, 95%CI = 1.85-2.63, p = 2.4 × 10(-11), respectively). Restriction of analysis to definite/probable cerebral amyloid angiopathy ICH uncovered a stronger effect. Allele ε4 was also associated with increased risk for deep ICH (OR = 1.21, 95% CI = 1.08-1.36, p = 2.6 × 10(-4)). Risk prediction evaluation identified the additive model as best for describing the effect of APOE genotypes. INTERPRETATION: APOE ε2 and ε4 are independent risk factors for lobar ICH, consistent with their known associations with amyloid biology. In addition, we present preliminary findings on a novel association between APOE ε4 and deep ICH. Finally, we demonstrate that an additive model for these APOE variants is superior to other forms of genetic risk modeling previously applied.

Frequency and syndrome specificity of antibodies to aquaporin-4 in neurological patients with rheumatic disorders.

BACKGROUND: A new autoantibody (termed NMO-IgG, or AQP4-Ab) has recently been described in patients with neuromyelitis optica (NMO) and its formes frustes, longitudinally extensive transverse myelitis (LETM) and recurrent optic neuritis (rON). However, AQP4-Ab has been found also in patients with co-existing rheumatic diseases such as systemic lupus erythematosus (SLE) or Sjögren's syndrome (SS), conditions which are characterized by broad, polyspecific B cell activation. OBJECTIVES: In this study, we aimed at evaluating the syndrome specificity and frequency of AQP4-Ab in patients with rheumatic diseases and neurological symptoms. METHODS: For this purpose, serum samples from 109 neurological patients with established connective tissue disorders (CTD) (n = 54), possible CTD (n = 42), or vasculitis (n = 13) were analysed for the presence of AQP4-Ab by a cell-based assay employing recombinant human AQP4. RESULTS: AQP4-Ab was detectable in 31/40 (78%) patients with CTD and NMO spectrum disorders (median titre, 1:1000) but in none of the samples obtained from patients with CTD or vasculitis and neurological disorders other than NMO, LETM, or rON (n = 69). CONCLUSION: The high syndrome specificity of the antibody for neuromyelitis optica spectrum disorders (NMOSDs) in patients with CTD supports the concept of AQP4-Ab being involved in the pathogenesis of these neurological conditions, and argues against AQP4-Ab simply being part of the polyclonal B cell activation generally associated with rheumatic diseases. Moreover, the finding that AQP4-Ab is present in patients with CTD and co-existing NMOSD with approximately the same frequency as in patients without CTD strengthens the case of CTD and AQP4-Ab positive NMOSD representing two co-existing yet distinct entities in the majority of patients.

Clinical core symptoms of posterior spinal artery ischemia.

INTRODUCTION: Ischemia in the distribution of the posterior spinal artery is rare. METHODS: Between 2004 and 2008 we observed 4 patients with posterior spinal artery ischemia (PSAI). RESULTS: All patients had the expected loss of posterior column function but also suffered from motor deficits which were severe, and the leading symptom in 2 patients. Severe pain, bowel and bladder dysfunction were other concomitant symptoms. In 3 of 4 patients, a follow-up spinal MRI was needed to show the cord infarct together with vertebral body ischemia in 2 patients. CONCLUSION: An acute onset of posterior column dysfunction with a variable degree of motor deficit and dorsalgia suggests PSAI.

Circle of Willis variants are not associated with thrombectomy outcomes.

BACKGROUND: The circle of Willis (COW) is part of the brain collateral system. The absence of COW segments may affect functional outcome in patients with ischaemic stroke undergoing endovascular therapy. METHODS: In 182 patients in the Diffusion and Perfusion Imaging Evaluation for Understanding Stroke Evolution 2 Study and the CT Perfusion to Predict Response to Recanalisation in Ischaemic Stroke Project, COW anatomy was evaluated on postinterventional magnetic resonance angiography. The absence of the posterior communicating artery or the first segments of posterior or anterior cerebral arteries ipsilateral to the ischaemic infarction was rated as an incomplete COW. Logistic regression was applied to evaluate an association with the patients' modified Rankin scale (mRS) at 90 days after stroke RESULTS: An incomplete ipsilateral COW was not predictive of the patients' mRS at 90 days after stroke. Significant associations were shown for the patients' baseline National Institutes of Health Stroke Scale (NIHSS), age and reperfusion status. The effect size suggests that a significant association of an incomplete COW with the mRS at 90 days may be obtained in cohorts of more than 3000 patients. CONCLUSIONS: Compared with the established predictors NIHSS, age and reperfusion status, an incomplete COW is not associated with functional outcome after endovascular therapy.