Progressive Multifocal Leukoencephalopathy Treated by Immune Checkpoint Inhibitors.

OBJECTIVE: Our aim was to assess the real-world effectiveness of immune checkpoint inhibitors for treatment of patients with progressive multifocal leukoencephalopathy (PML). METHODS: We conducted a multicenter survey compiling retrospective data from 79 PML patients, including 38 published cases and 41 unpublished cases, who received immune checkpoint inhibitors as add-on to standard of care. One-year follow-up data were analyzed to determine clinical outcomes and safety profile. Logistic regression was used to identify variables associated with 1-year survival. RESULTS: Predisposing conditions included hematological malignancy (n = 38, 48.1%), primary immunodeficiency (n = 14, 17.7%), human immunodeficiency virus/acquired immunodeficiency syndrome (n = 12, 15.2%), inflammatory disease (n = 8, 10.1%), neoplasm (n = 5, 6.3%), and transplantation (n = 2, 2.5%). Pembrolizumab was most commonly used (n = 53, 67.1%). One-year survival was 51.9% (41/79). PML-immune reconstitution inflammatory syndrome (IRIS) was reported in 15 of 79 patients (19%). Pretreatment expression of programmed cell death-1 on circulating T cells did not differ between survivors and nonsurvivors. Development of contrast enhancement on follow-up magnetic resonance imaging at least once during follow-up (OR = 3.16, 95% confidence interval = 1.20-8.72, p = 0.02) was associated with 1-year survival. Cerebrospinal fluid JC polyomavirus DNA load decreased significantly by 1-month follow-up in survivors compared to nonsurvivors (p < 0.0001). Thirty-two adverse events occurred among 24 of 79 patients (30.4%), and led to treatment discontinuation in 7 of 24 patients (29.1%). INTERPRETATION: In this noncontrolled retrospective study of patients with PML who were treated with immune checkpoint inhibitors, mortality remains high. Development of inflammatory features or overt PML-IRIS was commonly observed. This study highlights that use of immune checkpoint inhibitors should be strictly personalized toward characteristics of the individual PML patient. ANN NEUROL 2023;93:257-270.

Treatment of post-treatment Lyme disease symptoms-a systematic review.

BACKGROUND AND PURPOSE: Residual symptoms after treatment of Lyme disease, sometimes called post-treatment Lyme disease symptoms (PTLDs), are a matter of ongoing controversy. To guide treatment recommendations, a systematic review was performed of the available literature on specific treatment for PTLDs. METHODS: A systematic literature search of MEDLINE and CENTRAL was performed. No restrictions on case definitions, study types or specific interventions were applied to enable a comprehensive overview of the available literature. Risk of bias was assessed using the Cochrane risk of bias tools for randomized controlled trials. Certainty of the evidence was assessed using the Grading of Recommendations, Assessment, Development and Evaluation approach. Outcomes of interest were quality of life, fatigue, depression and cognition as well as adverse events. RESULTS: After screening 1274 records, eight eligible randomized controlled trials were included. Heterogeneity was observed regarding inclusion criteria, intervention, length of treatment and outcome measures. For efficacy outcomes, results are presented narratively due to heterogeneity. Eligible studies show no statistically significant difference between antibiotics and placebo regarding quality of life, cognition and depression. Results for fatigue were inconsistent whilst studies with low risk of bias showed no statistically significant difference between antibiotics and placebo. Meta-analysis of safety outcomes showed statistically significantly more adverse events for antibiotics compared to placebo. CONCLUSIONS: Available literature on treatment of PTLDs is heterogeneous, but overall shows evidence of no effect of antibiotics regarding quality of life, depression, cognition and fatigue whilst showing more adverse events. Patients with suspected PTLDs should not be treated with antibiotics.

Efficacy and safety of pharmacological treatments for Lyme neuroborreliosis: An updated systematic review.

BACKGROUND: Evidence-based recommendations for treatment of Lyme neuroborreliosis (LNB) should rely on the available literature. As new data emerges, close review and evaluation of the recent literature is needed to build evidence-based recommendations to inform clinical practice and management of LNB. We performed an update of a previous systematic review on treatment of LNB. METHODS: A systematic literature search of Medline and CENTRAL was performed for published studies from 2015 to 2023 to update a previous systematic review. Randomized controlled trials (RCTs) and non-randomized studies (NRS) were evaluated. Risk of bias was assessed using the Cochrane risk of bias tools for RCTs; NRS were assessed using the ROBINS-I-tool. Quality of the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. Data were integrated into an existing meta-analysis of the available literature. RESULTS: After screening 1530 records, two RCTs and five NRS with new and relevant data were additionally identified. Meta-analysis showed no statistically significant difference between doxycycline and beta-lactam antibiotics regarding residual neurological symptoms after 12 months. Meta-analysis showed no benefit of extended antibiotic treatment of LNB. Three NRS show no benefit for additional steroid use in LNB with facial palsy. DISCUSSION: Additional incorporated recent research corroborates existing guideline recommendations for treatment of LNB. New RCTs add to the certainty of previous analysis showing similar efficacy for doxycycline and beta-lactam antibiotics in LNB. Available evidence shows no benefit for extended antibiotic treatment in LNB. NRS do not suggest a role for steroids in facial palsy due to LNB.

Cerebrospinal fluid findings in COVID-19: a multicenter study of 150 lumbar punctures in 127 patients.

BACKGROUND: Comprehensive data on the cerebrospinal fluid (CSF) profile in patients with COVID-19 and neurological involvement from large-scale multicenter studies are missing so far. OBJECTIVE: To analyze systematically the CSF profile in COVID-19. METHODS: Retrospective analysis of 150 lumbar punctures in 127 patients with PCR-proven COVID-19 and neurological symptoms seen at 17 European university centers RESULTS: The most frequent pathological finding was blood-CSF barrier (BCB) dysfunction (median QAlb 11.4 [6.72-50.8]), which was present in 58/116 (50%) samples from patients without pre-/coexisting CNS diseases (group I). QAlb remained elevated > 14d (47.6%) and even > 30d (55.6%) after neurological onset. CSF total protein was elevated in 54/118 (45.8%) samples (median 65.35 mg/dl [45.3-240.4]) and strongly correlated with QAlb. The CSF white cell count (WCC) was increased in 14/128 (11%) samples (mostly lympho-monocytic; median 10 cells/µl, > 100 in only 4). An albuminocytological dissociation (ACD) was found in 43/115 (37.4%) samples. CSF L-lactate was increased in 26/109 (24%; median 3.04 mmol/l [2.2-4]). CSF-IgG was elevated in 50/100 (50%), but was of peripheral origin, since QIgG was normal in almost all cases, as were QIgA and QIgM. In 58/103 samples (56%) pattern 4 oligoclonal bands (OCB) compatible with systemic inflammation were present, while CSF-restricted OCB were found in only 2/103 (1.9%). SARS-CoV-2-CSF-PCR was negative in 76/76 samples. Routine CSF findings were normal in 35%. Cytokine levels were frequently elevated in the CSF (often associated with BCB dysfunction) and serum, partly remaining positive at high levels for weeks/months (939 tests). Of note, a positive SARS-CoV-2-IgG-antibody index (AI) was found in 2/19 (10.5%) patients which was associated with unusually high WCC in both of them and a strongly increased interleukin-6 (IL-6) index in one (not tested in the other). Anti-neuronal/anti-glial autoantibodies were mostly absent in the CSF and serum (1509 tests). In samples from patients with pre-/coexisting CNS disorders (group II [N = 19]; including multiple sclerosis, JC-virus-associated immune reconstitution inflammatory syndrome, HSV/VZV encephalitis/meningitis, CNS lymphoma, anti-Yo syndrome, subarachnoid hemorrhage), CSF findings were mostly representative of the respective disease. CONCLUSIONS: The CSF profile in COVID-19 with neurological symptoms is mainly characterized by BCB disruption in the absence of intrathecal inflammation, compatible with cerebrospinal endotheliopathy. Persistent BCB dysfunction and elevated cytokine levels may contribute to both acute symptoms and 'long COVID'. Direct infection of the CNS with SARS-CoV-2, if occurring at all, seems to be rare. Broad differential diagnostic considerations are recommended to avoid misinterpretation of treatable coexisting neurological disorders as complications of COVID-19.

Fabrication, Flow Assembly, and Permeation of Microscopic Any-Shape Particles.

Today, millimeter-sized nonspherical any-shape particles serve as flexible, functional scaffold material in chemical and biochemical reactors tailoring their hydrodynamic properties and active surface-to-volume ratio based on the particle's shape. Decreasing the particle size to smaller than 100 µm would be desired as it increases the surface-to-volume ratio and promotes a particle assembly based on surface interactions, allowing the creation of tailored self-assembling 3D scaffolds. This study demonstrates a continuous high-throughput fabrication of microscopic 3D particles with complex shape and sub-micron resolution using continuous two-photon vertical flow lithography. Evolving from there, in-channel particle fabrication into a confined microfluidic chamber with a resting fluid enables the precise fabrication of a defined number of particles. 3D assemblies with various particle shapes are fabricated and analyzed regarding their permeability and morphology, representing convective accessibility of the assembly's porosity. Differently shaped particles highlight the importance of contact area regarding particle-particle interactions and the respective hydraulic resistance of an assembly. Finally, cell culture experiments show manifold cell-particle interactions promising applicability as bio-hybrid tissue. This study pushes the research boundaries of adaptive, responsive, and permeable 3D scaffolds and granular media by demonstrating a high throughput fabrication solution and a precise hydrodynamic analysis method for micro-particle assemblies.

Mimicking the Natural Basement Membrane for Advanced Tissue Engineering.

Advancements in the field of tissue engineering have led to the elucidation of physical and chemical characteristics of physiological basement membranes (BM) as specialized forms of the extracellular matrix. Efforts to recapitulate the intricate structure and biological composition of the BM have encountered various advancements due to its impact on cell fate, function, and regulation. More attention has been paid to synthesizing biocompatible and biofunctional fibrillar scaffolds that closely mimic the natural BM. Specific modifications in biomimetic BM have paved the way for the development of in vitro models like alveolar-capillary barrier, airway models, skin, blood-brain barrier, kidney barrier, and metastatic models, which can be used for personalized drug screening, understanding physiological and pathological pathways, and tissue implants. In this Review, we focus on the structure, composition, and functions of in vivo BM and the ongoing efforts to mimic it synthetically. Light has been shed on the advantages and limitations of various forms of biomimetic BM scaffolds including porous polymeric membranes, hydrogels, and electrospun membranes This Review further elaborates and justifies the significance of BM mimics in tissue engineering, in particular in the development of in vitro organ model systems.

COVID-19 pneumonia in a multiple sclerosis patient with severe lymphopenia due to recent cladribine treatment.

BACKGROUND: Most cases of COVID-19 are considered mild, but patients with immunosuppressant treatment might be prone to severe courses of disease. Expert panels advise to delay treatment with cell-depleting MS therapies during the COVID-19 pandemic. METHODS: We report a case of a patient with relapsing-remitting multiple sclerosis who developed COVID-19 pneumonia 2 weeks after the first week of cladribine therapy. RESULTS: Despite a severe lymphopenia (absolute lymphocyte count 240/µL), the patient had a moderate course of COVID-19. CONCLUSION: Apart from maximal supportive treatment, this could be due to cladribine reducing inflammatory response, which probably contributes considerably to severe courses of COVID-19 pneumonia.

Autoimmune encephalitis as a differential diagnosis of schizophreniform psychosis: clinical symptomatology, pathophysiology, diagnostic approach, and therapeutic considerations.

Primary schizophreniform psychoses are thought to be caused by complex gene-environment interactions. Secondary forms are based on a clearly identifiable organic cause, in terms of either an etiological or a relevant pathogenetic factor. The secondary or "symptomatic" forms of psychosis have reentered the focus stimulated by the discovery of autoantibody (Ab)-associated autoimmune encephalitides (AEs), such as anti-NMDA-R encephalitis, which can at least initially mimic variants of primary psychosis. These newly described secondary, immune-mediated schizophreniform psychoses typically present with the acute onset of polymorphic psychotic symptoms. Over the course of the disease, other neurological phenomena, such as epileptic seizures, movement disorders, or reduced levels of consciousness, usually arise. Typical clinical signs for AEs are the acute onset of paranoid hallucinatory symptoms, atypical polymorphic presentation, psychotic episodes in the context of previous AE, and additional neurological and medical symptoms such as catatonia, seizure, dyskinesia, and autonomic instability. Predominant psychotic courses of AEs have also been described casuistically. The term autoimmune psychosis (AP) was recently suggested for these patients. Paraclinical alterations that can be observed in patients with AE/AP are inflammatory cerebrospinal fluid (CSF) pathologies, focal or generalized electroencephalographic slowing or epileptic activity, and/or suspicious "encephalitic" imaging findings. The antibody analyses in these patients include the testing of the most frequently found Abs against cell surface antigens (NMDA-R, CASPR2, LGI1, AMPA-R, GABAB-R), intracellular antigens (Hu, Ri, Yo, CV2/CRMP5, Ma2 [Ta], amphiphysin, GAD65), thyroid antigens (TG, TPO), and antinuclear Abs (ANA). Less frequent antineuronal Abs (e.g., against DPPX, GABAA-R, glycine-R, IgLON5) can be investigated in the second step when first step screening is negative and/or some specific clinical factors prevail. Beyond, tissue-based assays on brain slices of rodents may detect previously unknown antineuronal Abs in some cases. The detection of clinical and/or paraclinical pathologies (e.g., pleocytosis in CSF) in combination with antineuronal Abs and the exclusion of alternative causes may lead to the diagnosis of AE/AP and enable more causal therapeutic immunomodulatory opportunities.

Severe meningo-/encephalitis after daclizumab therapy for multiple sclerosis.

BACKGROUND: Daclizumab is a monoclonal antibody that binds the high-affinity interleukin-2 receptor and was approved for the treatment of relapsing multiple sclerosis. Due to severe inflammatory brain disorders, the approval was suspended in March 2018. OBJECTIVE AND METHODS: This retrospective cohort study summarizes clinical, laboratory, radiological, and histological findings of seven patients who developed meningo-/encephalitis after daclizumab therapy. RESULTS: Patients presented with encephalitis and/or meningitis and suffered from systemic symptoms such as fever (5/7), exanthema (5/7), or gastrointestinal symptoms (4/7). Secondary autoimmune diseases developed. Blood analysis revealed an increase in eosinophils (5/7). Six patients fulfilled the diagnostic criteria for a drug reaction with eosinophilia and systemic symptoms (DRESS). Magnetic resonance imaging (MRI) showed multiple contrast-enhancing lesions, and enhancement of the ependyma (6/7), meninges (5/7), cranial or spinal nerves (2/7), and a vasculitic pattern (3/7). Histology revealed a pronounced inflammatory infiltrate consisting of lymphocytes, plasma cells and eosinophils, and densely infiltrated vessels. Most patients showed an insufficient therapeutic response and a high disability at last follow-up (median Expanded Disability Status Scale (EDSS) 8). Two patients died. CONCLUSION: Meningoencephalitis and DRESS may occur with daclizumab therapy. This potential lethal side effect is characterized by a dysregulated immune response. Our findings underline the importance of postmarketing drug surveillance.

The MRZ reaction helps to distinguish rheumatologic disorders with central nervous involvement from multiple sclerosis.

BACKGROUND: Some rheumatologic disorders may initially manifest with central nervous system (CNS) affection, mimicking the clinical, magnetic resonance imaging, and cerebrospinal fluid findings of multiple sclerosis (MS). The MRZ reaction (MRZR), composed of the three respective antibody indices (AIs) against measles, rubella, and varicella zoster virus, has been found positive frequently in MS patients. However, it is unclear whether the MRZR is helpful to distinguish rheumatologic disorders with CNS involvement (RDwCNS) from MS. METHODS: The MRZR was evaluated in patients with RDwCNS (n = 23), MS (n = 46; age and sex matched to patients with RDwCNS), and other inflammatory autoimmune neurological diseases affecting the CNS (OIND; n = 48). Both the stringency levels that have been used in previous MRZR studies, MRZR-1 (≥ 1 of 3 AIs positive) and MRZR-2 (≥ 2 of 3 AIs positive), were applied. RESULTS: There was no statistically significant difference in the prevalence of positive MRZR between patients with RDwCNS (MRZR-1: 13.0% and MRZR-2: 8.7%, respectively) and OIND (MRZR-1: 22.9% and MRZR-2: 8.3%, respectively). Compared to these two study cohorts, the MS group exhibited significantly higher prevalences of positive MRZR (MRZR-1: 82.6%, MRZR-2: 63.0%; p < 0.005 each). CONCLUSIONS: Considering the high specificity of MRZR-2 for MS found in this study, MRZR-2 can be a useful diagnostic tool for distinguishing MS from RDwCNS or OIND.

Regional neuronal activity in patients with relapsing remitting multiple sclerosis.

OBJECTIVES: Although interferon-beta is an established drug for relapsing remitting multiple sclerosis (RRMS), its impact on neuronal activity is not well understood. METHODS: We investigated 15 patients with RRMS by [18 F]fluorodeoxyglucose positron emission tomography (FDG-PET) to assess cerebral metabolic rate of glucose (CMRglc ) before interferon-beta therapy. Further, we performed clinical and neuropsychological investigations. In nine patients, these investigations were repeated after 6 months of therapy. Ten healthy controls were also studied. RESULTS: We found no significant differences in absolute CMRglc between patients and controls, or in patients before and during treatment. However, during treatment, relative regional glucose metabolism (rCMRlglc ) was decreased in cerebellum and increased in parts of left inferior parietal, temporo-occipital, frontal cortical areas, left striatum and right insula. In untreated patients, higher fatigue was associated with lower rCMRlglc in portions of left posterior cingulate cortex, and higher depression was associated with lower rCMRlglc within the left superior temporal sulcus. In the pooled sample, higher depression was associated with higher rCMRlglc in parts of the right precuneus. CONCLUSIONS: Our results indicate effects of IFN-beta treatment on cerebellar, cortical and subcortical neuronal function. Moreover, more severe fatigue and depression in untreated patients seem to be associated with reduced neuronal activity in left posterior cingulate cortex and left superior temporal cortex, respectively.

Screening for onconeural antibodies in neuromyelitis optica spectrum disorders.

BACKGROUND: Some so-called "non-classical" paraneoplastic neurological syndromes (PNS), namely optic neuritis and myelitis, clinically overlap with neuromyelitis optica spectrum disorders (NMOSD), and conversely, in cancer-associated NMOSD, a paraneoplastic etiology has been suggested in rare cases. Therefore, we retrospectively investigated the prevalence of onconeural antibodies, which are highly predictive for a paraneoplastic etiology, and the prevalence of malignancies in NMOSD patients. METHODS: We retrospectively screened 23 consecutive patients from our clinic with NMOSD (13 were anti-aquaporin-4 [AQP4] antibody positive, 10 were AQP4 negative) for onconeural antibodies using an immunoblot. RESULTS: All patients were negative for a broad spectrum of antibodies targeting intracellular onconeural antigens (Hu, Yo, Ri, CV2/CRMP5, Ma1, Ma2, Zic4, SOX1, Tr, and amphiphysin). Notably, only two patients had a malignancy. However, neoplastic entities (astrocytic brain tumor and acute myeloid leukemia) were not typical for PNS. CONCLUSIONS: Our data suggest that there is no need to routinely screen anti-AQP4 antibody positive NMOSD patients with a typical presentation for onconeural antibodies. Furthermore, absence of these antibodies in NMOSD, which is typically non-paraneoplastic, confirms their high specificity for PNS.

Efficacy and safety of pharmacological treatments for Lyme neuroborreliosis in children: a systematic review.

BACKGROUND: Many aspects of pharmacological treatment of Lyme neuroborreliosis in children, such as choice of drug, dosage, and duration are subject to intense debates, leading to uncertainties in patients' parents and healthcare providers alike. To assess the available evidence for pharmacological treatment for children with Lyme neuroborreliosis we conducted a systematic review. METHODS: The comprehensive systematic literature search included randomized-controlled trials (RCTs) and non-randomized studies (NRS) on treatment of Lyme neuroborreliosis in children (age <18 years). Our primary outcome was neurological symptoms after treatment. Risk of bias was assessed with the Cochrane risk of bias tools for RCTs and NRS. Quality of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. RESULTS: Two RCTs and four NRS were eligible for inclusion. Risk of bias in RCTs and NRS was generally high. Reporting of studies was generally poor. Regarding the primary outcome neurological symptoms at 1-3 months, no statistically significant difference could be found in cohort studies between doxycycline and beta-lactam antibiotics. In two RCTs comparing penicillin G and ceftriaxone, no patient experienced residual neurological symptoms at the last reported time points. Quality of evidence according to GRADE was judged very low. CONCLUSIONS: Data is scarce and with limited quality. Several issues could not be addressed due to scarcity of information. No eligible study compared different treatment durations. According to the available evidence, there seems to be no difference between different antibiotic agents for the treatment of Lyme neuroborreliosis in children regarding neurological symptoms. We found no evidence that supports extended antibiotic regimes. REVIEW REGISTRATION: Systematic review registration: CRD42014008839 .

Cerebrospinal fluid profile and seroprevalence of antiganglioside reactivity in patients with neuralgic amyotrophy.

Neuralgic amyotrophy (NA), also known as acute brachial plexitis, is postulated as an autoimmune pathogenesis. In a well-defined cohort of patients with NA, we analyzed the cerebrospinal fluid (CSF) profile and the prevalence of antiganglioside antibodies. Patients with Varicella zoster-associated radiculitis and healthy blood donors served as controls. An abnormal routine laboratory CSF profile was found in 29% of those with NA, mostly showing a disruption of the blood-brain barrier. Antibodies predominantly from the immunoglobulin M (IgM) isotype against at least one human ganglioside were detected in 36% of sera from patients with NA but in only 2% of controls. An NA-specific reactivity pattern was not detected, and there was no significant association with clinical or CSF parameters. This suggests that the seroprevalence of antiganglioside autoantibodies in patients with NA is nonspecific.

An observational study of inflammation in the central nervous system in patients with bipolar disorder.

OBJECTIVES: The potential influence of infections and immunological changes on the aetiology and pathogenesis of bipolar disorder (BD) has been discussed. Our aim was to detect intrathecal specific antibody synthesis against the neurotropic infectious agents that have previously been linked to BD. METHODS: Paired cerebrospinal fluid (CSF) and serum samples from 40 patients with BD were analysed using the enzyme-linked immunosorbent assay to detect the concentration of antibodies against the following neurotropic infectious pathogens: Toxoplasma gondii (T. gondii), herpes simplex virus (HSV) types 1 and 2, cytomegalovirus (CMV), and Epstein-Barr virus (EBV). The specific antibody index (AI) was calculated, and an AI > 1.4 was considered to be evidence of intrathecal specific antibody synthesis. Twenty-six patients with pseudotumour cerebri served as controls. RESULTS: Eight out of 40 patients with BD displayed specific intrathecal antibody synthesis against at least one of the tested neurotropic agents compared to only one patient in the control group (p = 0.061, not significant). Of these eight patients with BD, no significant prevalence of any particular neurotropic pathogen was evident. Five out of 40 patients with BD showed oligoclonal bands in the CSF, suggestive of a chronic immune reaction in the central nervous system (CNS). CONCLUSIONS: We found evidence for increased production of antibody in the CSF of individuals with BD. However, the trend for polyspecific intrathecal antibody synthesis, as well as the presence of oligoclonal bands, might indicate activation of the intrathecal humoral immune system in a subgroup of patients with BD, as it is known to be associated with autoimmune disorders of the CNS.

Transient spurious intrathecal immunoglobulin synthesis in neurological patients after therapeutic apheresis.

BACKGROUND: The analysis of cerebrospinal fluid (CSF) is usually done under steady-state conditions, when proteins (e.g., immunoglobulins) reach diffusion equilibrium between blood and CSF. However, little data has been published on CSF analysis under non-steady-state conditions after therapeutic apheresis. By reducing serum proteins (e.g., immunoglobulins), while leaving CSF unchanged, therapeutic apheresis might cause spuriously altered intrathecal immunoglobulin fractions. METHODS: Based on the incidental finding of plasma exchange-induced increased intrathecal immunoglobulin fractions in a cohort of 12 unsystematically selected patients with various neurological disorders, we retrospectively investigated CSF results that had been raised during routine diagnostic work-up from 41 consecutive neurological patients (predominantly Guillain-Barré syndrome and autoimmune encephalitis) treated with plasmapheresis or immunoadsorption in a tertiary care university hospital in whom lumbar puncture (LP) was performed after a varying number of treatments of therapeutic apheresis. RESULTS: Only when LP was performed 1 day after therapeutic apheresis, spurious quantitative intrathecal immunoglobulin (Ig) synthesis of at least one subclass (IgG, IgA and/or IgM) was found in 68.4 % of the patients, irrespective of the number of treatments, in all age groups and independent of other previous immunotherapies (e.g., steroids). This phenomenon occurred only transiently and was almost always accompanied by an elevation of the IgG index. In one patient, an elevated IgG index was noticed even 2 days after plasmapheresis. Neither quantitative Ig synthesis, nor elevated IgG index was observed when the LP was performed three or more days after therapeutic apheresis. CONCLUSIONS: Spurious quantitative intrathecal Ig synthesis and increased IgG index are common findings shortly after plasmapheresis or immunoadsorption due to altered serum immunoglobulin levels. Knowledge of this phenomenon is needed for clinicians to prevent false interpretations leading to unnecessary diagnostic and therapeutic procedures. Misdiagnoses can be avoided by considering the characteristic CSF constellation including absence of oligoclonal bands and the close temporal relation to therapeutic apheresis.

Hypoglutamatergic state is associated with reduced cerebral glucose metabolism in anti-NMDA receptor encephalitis: a case report.

BACKGROUND: Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis was first described in 2005 in association with ovarian teratoma. The diagnostic workup of this common autoimmune encephalitis includes cerebrospinal fluid analysis, electroencephalography, magnetic resonance imaging (MRI), and fluorodeoxyglucose positron emission tomography (FDG-PET). In addition to standard diagnostics, we performed metabolic investigations using proton magnet resonance spectroscopy ((1)H-MRS). CASE PRESENTATION: We describe the case of a non-limbic anti-NMDAR encephalitis with a long course of disease (21 months). Laboratory diagnostics showed antibodies against NMDAR; an MRI revealed unspecific findings. (1)H-MRS indicated a hypoglutamatergic state in the left prefrontal cortex associated with a left hemispherical hypometabolism on FDG-PET. Despite the long course of disease, immunosuppressive therapy with methylprednisolone and azathioprine led to almost complete remission of clinical symptoms. Clinical improvement developed in parallel with remarkable normalization of cerebral glucose metabolism on FDG-PET. CONCLUSION: This case of long-lasting extra-limbic anti-NMDAR encephalitis is of high clinical relevance. First, it illustrates that a very good outcome is possible even if adequate therapy is started only 21 months after the onset of severe symptoms. Second, it provides valuable insights into the pathophysiology of such anti-NMDAR encephalitis; these insights prove that anti-NMDAR encephalitis is linked not only to hyperglutamatergic signals but also to hypoglutamatergic states. These findings, contradictory at first glance, can be integrated within the model of excitatory/inhibitory imbalance and local area network inhibition.

Sphingosine-1-phosphate receptors control B-cell migration through signaling components associated with primary immunodeficiencies, chronic lymphocytic leukemia, and multiple sclerosis.

BACKGROUND: Five different G protein-coupled sphingosine-1-phosphate (S1P) receptors (S1P1-S1P5) regulate a variety of physiologic and pathophysiologic processes, including lymphocyte circulation, multiple sclerosis (MS), and cancer. Although B-lymphocyte circulation plays an important role in these processes and is essential for normal immune responses, little is known about S1P receptors in human B cells. OBJECTIVE: To explore their function and signaling, we studied B-cell lines and primary B cells from control subjects, patients with leukemia, patients with S1P receptor inhibitor-treated MS, and patients with primary immunodeficiencies. METHODS: S1P receptor expression was analyzed by using multicolor immunofluorescence microscopy and quantitative PCR. Transwell assays were used to study cell migration. S1P receptor internalization was visualized by means of time-lapse imaging with fluorescent S1P receptor fusion proteins expressed by using lentiviral gene transfer. B-lymphocyte subsets were characterized by means of flow cytometry and immunofluorescence microscopy. RESULTS: Showing that different B-cell populations express different combinations of S1P receptors, we found that S1P1 promotes migration, whereas S1P4 modulates and S1P2 inhibits S1P1 signals. Expression of CD69 in activated B lymphocytes and B cells from patients with chronic lymphocytic leukemia inhibited S1P-induced migration. Studying B-cell lines, normal B lymphocytes, and B cells from patients with primary immunodeficiencies, we identified Bruton tyrosine kinase, ß-arrestin 2, LPS-responsive beige-like anchor protein, dedicator of cytokinesis 8, and Wiskott-Aldrich syndrome protein as critical signaling components downstream of S1P1. CONCLUSION: Thus S1P receptor signaling regulates human B-cell circulation and might be a factor contributing to the pathology of MS, chronic lymphocytic leukemia, and primary immunodeficiencies.

Differentiating cerebral ischemia from functional neurological symptom disorder: a psychosomatic perspective.

BACKGROUND: The differential diagnosis of pseudo-neurological symptoms often represents a clinical challenge. The Diagnostic and Statistical Manual of Mental Disorders, DSM-5, made an attempt to improve diagnostic criteria of conversion disorder (functional neurological symptom disorder). Incongruences of the neurological examination, i.e. positive neurological signs, indicate a new approach--whereas psychological factors are not necessary anymore. As the DSM-5 will influence the International Classification of Diseases, ICD-11, this is of importance. In the case presented, a history of psychological distress and adverse childhood experiences coexisted with a true neurological disorder. We discuss the relevance of an interdisciplinary assessment and of operationalized diagnostic criteria. CASE PRESENTATION: A 32-year-old man presented twice with neurological symptoms without obvious pathological organic findings. A conversion disorder was considered early on at the second admission by the neurology team. Sticking to ICD-10, this diagnosis was not supported by a specialist for psychosomatic medicine, due to missing hints of concurrent psychological distress in temporal association with neurological symptoms. Further investigations then revealed a deep vein thrombosis (though D-dimers had been negative), which had probably resulted in a crossed embolus. CONCLUSION: The absence of a clear proof of biological dysfunction underlying neurological symptoms should not lead automatically to the diagnosis of a conversion disorder. In contrast, at least in more complex patients, the work-up should include repeated psychological and neurological assessments in close collaboration. According to ICD-10 positive signs of concurrent psychological distress are required, while DSM-5 emphasizes an incongruity between neurological symptoms and neurophysiological patterns of dysfunction. In the case presented, an extensive medical work-up was initially negative, and neither positive psychological nor positive neurological criteria could be identified. We conclude, that, even in times of more sophisticated operationalization of diagnostic criteria, the interdisciplinary assessment has to be based on an individual evaluation of all neurological and psychosocial findings. Prospective studies of inter-rater reliability and validity of psychological factors and positive neurological signs are needed, as evidence for both is limited. With respect to ICD-11, we suggest that positive neurological as well as psychological signs for functional neurological symptom disorder should be considered to increase diagnostic certainty.