[Biomarkers for dementia and other neurodegenerative diseases : Current developments]. / Biomarker bei Demenzen und anderen neurodegenerativen Erkrankungen : Aktuelle Entwicklungen.

Cerebrospinal fluid-based neurochemical dementia diagnostics (CSF-NDD) support the early and differential diagnosis of dementia, most importantly the diagnosis of early or preclinical Alzheimer's dementia (AD). Meanwhile CSF-NDD are now recommended for improved exclusion and positive diagnostics of AD by the German national neuropsychiatry S3 dementia guidelines ( www.DGPPN.de ). Meta-analyses of independent international multicenter studies have shown that a combined CSF analysis of amyloid-beta 1-42 (Aß 1-42, decreased), total tau proteins (increased) and phospho-tau proteins (increased) offers a sensitivity and specificity of 80-90 % for the early and differential diagnosis of AD (AD versus all other). Generally, CSF-NDD should be combined with blood-based routine diagnostics and should be part of routine CSF diagnostics, e. g. cell count and cell differentiation (if applicable), intrathecal antibody synthesis and blood-CSF barrier analysis. The CSF-NDD are most valuable for the improved differentiation between reversible dementia syndromes and irreversible neurodegenerative dementia, e. g. cognitive deficits due to late onset depression (pseudodementia due to depression) or AD. Combined with extended psychometric neuropsychological evaluation and neuroimaging methods, such as magnetic resonance imaging (MRI), dopamine transporter scanning (DaTscan) by single photon emission computed tomography (SPECT), 18F-fluorodeoxyglucose positron emission tomography (glucose-PET) and amyloid-PET, CSF-NDD also significantly improve the differential diagnostics within the heterogeneous group of primary neurodegenerative dementias. Meanwhile, several independent studies have indicated that the Aß 1-42:Aß 1-40 ratio is superior to the determination of Aß 1-42 alone. Currently, several international research initiatives have been launched to further harmonize and optimize preanalytical procedures and CSF-NDD biomarker assays.

Soluble amyloid precursor proteins in the cerebrospinal fluid as novel potential biomarkers of Alzheimer's disease: a multicenter study.

In this report, we present the results of a multicenter study to test analytic and diagnostic performance of soluble forms of amyloid precursor proteins alpha and beta (sAPP alpha and sAPP beta) in the cerebrospinal fluid (CSF) of patients with different forms of dementing conditions. CSF samples were collected from 188 patients with early dementia (mini-mental state examination >or=20 in majority of cases) and mild cognitive impairment (MCI) in 12 gerontopsychiatric centers, and the clinical diagnoses were supported by neurochemical dementia diagnostic (NDD) tools: CSF amyloid beta peptides, Tau and phospho-Tau. sAPP alpha and sAPP beta were measured with multiplexing method based on electrochemiluminescence. sAPP alpha and sAPP beta CSF concentrations correlated with each other with very high correlation ratio (R=0.96, P<0.001). We observed highly significantly increased sAPP alpha and sAPP beta CSF concentrations in patients with NDD characteristic for Alzheimer's disease (AD) compared to those with NDD negative results. sAPP alpha and sAPP beta highly significantly separated patients with AD, whose diagnosis was supported by NDD findings (sAPP alpha: cutoff, 117.4 ng ml(-1), sensitivity, 68%, specificity, 85%, P<0.001; sAPP beta: cutoff, 181.8 ng ml(-1), sensitivity, 75%, specificity, 85%, P<0.001), from the patients clinically assessed as having other dementias and supported by NDD untypical for AD. We conclude sAPP alpha and sAPP beta might be regarded as novel promising biomarkers supporting the clinical diagnosis of AD.

[The future of biomarkers in dementia diagnostics]. / Die Zukunft der Biomarker in der Demenzdiagnostik.

Neurochemical dementia diagnostics (NDD) is a routine laboratory tool in the diagnostic process of patients with neurodegenerative disorders, such as Alzheimer's disease (AD). Currently, two groups of biomarkers analyzed in the cerebrospinal fluid (CSF) are being considered, namely amyloid ß (Aß) peptides and tau proteins, along with the hyperphosphorylated forms of the latter (p-tau). Current directions in the development of NDD include the following: 1. search for novel biomarkers with improved analytical or diagnostic performance; 2. search for biomarkers in the blood; 3. applications of novel technologies enabling better management of patient samples; 4. optimization of the analysis of the biomarkers already available (for example, by improved quality control and inter-laboratory comparison of results). This review presents the state of the art in the field of CSF-based NDD and also summarizes some of the hypotheses of how the future development of NDD tools might look.

S1 guidelines "lumbar puncture and cerebrospinal fluid analysis" (abridged and translated version).

INTRODUCTION: Cerebrospinal fluid (CSF) analysis is important for detecting inflammation of the nervous system and the meninges, bleeding in the area of the subarachnoid space that may not be visualized by imaging, and the spread of malignant diseases to the CSF space. In the diagnosis and differential diagnosis of neurodegenerative diseases, the importance of CSF analysis is increasing. Measuring the opening pressure of CSF in idiopathic intracranial hypertension and at spinal tap in normal pressure hydrocephalus constitute diagnostic examination procedures with therapeutic benefits.Recommendations (most important 3-5 recommendations on a glimpse): The indications and contraindications must be checked before lumbar puncture (LP) is performed, and sampling CSF requires the consent of the patient.Puncture with an atraumatic needle is associated with a lower incidence of postpuncture discomfort. The frequency of postpuncture syndrome correlates inversely with age and body mass index, and it is more common in women and patients with a history of headache. The sharp needle is preferably used in older or obese patients, also in punctures expected to be difficult.In order to avoid repeating LP, a sufficient quantity of CSF (at least 10 ml) should be collected. The CSF sample and the serum sample taken at the same time should be sent to a specialized laboratory immediately so that the emergency and basic CSF analysis program can be carried out within 2 h.The indication for LP in anticoagulant therapy should always be decided on an individual basis. The risk of interrupting anticoagulant therapy must be weighed against the increased bleeding risk of LP with anticoagulant therapy.As a quality assurance measure in CSF analysis, it is recommended that all cytological, clinical-chemical, and microbiological findings are combined in an integrated summary report and evaluated by an expert in CSF analysis. CONCLUSIONS: In view of the importance and developments in CSF analysis, the S1 guideline "Lumbar puncture and cerebrospinal fluid analysis" was recently prepared by the German Society for CSF analysis and clinical neurochemistry (DGLN) and published in German in accordance with the guidelines of the AWMF (https://www.awmf.org). /uploads/tx_szleitlinien/030-141l_S1_Lumbalpunktion_und_Liquordiagnostik_2019-08.pdf). The present article is an abridged translation of the above cited guideline. The guideline has been jointly edited by the DGLN and DGN.

Evolution of Abeta42 and Abeta40 levels and Abeta42/Abeta40 ratio in plasma during progression of Alzheimer's disease: a multicenter assessment.

OBJECTIVE: To better understand the seemingly contradictory plasma beta-amyloid (Abeta) results in Alzheimer's disease (AD) patients by using a newly developed plasma Abeta assay, the INNO-BIA plasma Abeta forms, in a multicenter study. METHODS: A combined retrospective analysis of plasma Abeta isoforms on mild cognitive impairment (MCI) from three large cross-sectional studies involving 643 samples from the participating German and Swedish centers. RESULTS: Detection modules based on two different amino (N)-terminal specific Abeta monoclonal antibodies demonstrated that Abeta in plasma could be reliable quantified using a sandwich immunoassay technology with high precision, even for low Abeta42 plasma concentrations. Abeta40 and Abeta42 concentrations varied consistently with the ApoE genotype, while the Abeta42/Abeta40 ratio did not. Irrespective of the decrease of the Abeta42/Abeta40 ratio with age and MMSE, this parameter was strongly associated with AD, as defined in this study by elevated hyperphosphorylated (P-tau181P) levels in cerebrospinal fluid (CSF). CONCLUSION: A highly robust assay for repeatedly measuring Abeta forms in plasma such as INNO-BIA plasma Abeta forms might be a useful tool in a future risk assessment of AD.

[Physical activity and prevention of Alzheimer's dementia: current evidence and feasibility of an interventional trial]. / Körperliche Aktivität und Prävention der Alzheimerdemenz: Ubersicht über die aktuelle Evidenz und Uberlegungen zur Machbarkeit einer Interventionsstudie.

There is accumulating evidence from animal and epidemiologic studies that physical exercise is neuroprotective in healthy animals and humans and can prevent cognitive decline in chronic neurodegenerative processes like Alzheimer's dementia. However, data from well-designed interventional, randomized non-pharmacologic trials is lacking in contrast to other areas of medicine like prevention of hypertension, diabetes or the antipsychotic-associated metabolic syndrome. The demonstration of a potential positive effect of physical exercise on preventing dementia using a controlled study design would represent a significant progress in the prevention of dementia and public health, especially as long as other treatments for dementia prevention are lacking.

[Sensitivity of neurochemical dementia diagnostics in CSF compared to 99mTc-SPECT in Alzheimer's dementia]. / Vergleichende Sensitivität der neurochemischen Demenzdiagnostik im Liquor und rCBF im 99mTc-SPECT bei Patienten mit Alzheimerdemenz.

The diagnosis of Alzheimer's dementia is currently changing from a late and exclusion diagnosis towards a pathophysiology-based early and positive diagnosis. Especially advances in neuro-chemical dementia diagnostics in the cerebrospinal fluid (NDD-CSF) and imaging techniques like PET, SPECT or MRI are of particular interest. Unfortunately, many studies investigated only either one or other technique. In the present study 56 patients (average 67.1 years; average mini-mental status test (MMST) 22.2) were examined with the clinical diagnosis of Alzheimer's dementia. All patients both underwent NDD-CSF as well as 99mTc-SPECT. Only the SPECT, but not the NDD-CSF correlated with disease severity. Sensitivity of NDD-CSF was 89 % and SPECT 48 % for all patients and 93 % resp. 61 % for patients with MMST < 24. Below MMST 20 both methods had equal sensitivity. Both diagnostic techniques showed no statistic coherence (p = 0.27), neither after correction for subgroups like disease severity or the APOE genotype. Our results are compatible with the hypothesis that the NDD-CSF reflects beta-amyloid-aggregation and Tau-Protein pathology as a pathophysiologic biomarker. Our results suggest that SPECT is rather a state parameter for the rCBF changes following cortical neurodegeneration.

Prediction of Alzheimer's disease using a cerebrospinal fluid pattern of C-terminally truncated beta-amyloid peptides.

BACKGROUND: Identifying individuals at high risk of developing Alzheimer's disease (AD) is important for future therapeutic strategies, and there is a clinical need for diagnostic biomarkers to identify incipient AD. OBJECTIVE: The aim of the present study was to investigate if the AD-associated Abeta peptide pattern recently found in cerebrospinal fluid (CSF) could discriminate between patients with incipient AD and those with stable mild cognitive impairment (MCI) by analyzing CSF from patients with MCI at baseline. METHODS: The levels of Abeta(1-37, -38, -39, -40, -42) were analyzed by Abeta-SDS-PAGE/immunoblot in CSF from 19 healthy controls, 25 patients with stable MCI and from 25 patients with MCI who later developed AD during 4- to 6-year follow-up. RESULTS: All healthy controls and 20 out of 22 patients who developed AD were correctly classified by their baseline Abeta peptide pattern. In 9 out of 25 stable MCI patients, the pattern indicated incipient AD in spite of clinical nonconversion. Interestingly, these individuals had apolipoprotein E genotypes and CSF levels of tau and phospho-tau that are known to be associated with high risk of AD. CONCLUSION: Altogether, our study reveals the novel finding that the Abeta peptide pattern is able to predict AD in patients with MCI with a sensitivity of 91% and specificity of 64%. The specificity would increase to 94% if the high-risk patients in the stable MCI cohort developed AD during extended follow-up.

Consensus paper of the WFSBP Task Force on Biological Markers of Dementia: the role of CSF and blood analysis in the early and differential diagnosis of dementia.

Aging of population, and increasing life expectancy result in an increasing number of patients with dementia. This symptom can be a part of a completely curable disease of the central nervous system (e.g, neuroinflammation), or a disease currently considered irreversible (e.g, Alzheimer's disease, AD). In the latter case, several potentially successful treatment approaches are being tested now, demanding reasonable standards of pre-mortem diagnosis. Cerebrospinal fluid and serum analysis (CSF/serum analysis), whereas routinely performed in neuroinflammatory diseases, still requires standardization to be used as an aid to the clinically based diagnosis of AD. Several AD-related CSF parameters (total tau, phosphorylated forms of tau, Abeta peptides, ApoE genotype, p97, etc.) tested separately or in a combination provide sensitivity and specificity in the range of 85%, the figure commonly expected from a good diagnostic tool. In this review, recently published reports regarding progress in neurochemical pre-mortem diagnosis of dementias are discussed with a focus on an early and differential diagnosis of AD. Novel perspectives offered by recently introduced technologies, e.g, fluorescence correlation spectroscopy (FCS) and surface enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF MS) are briefly discussed.

Intercellular adhesion molecule-1 in cerebrospinal fluid--the evaluation of blood-derived and brain-derived fractions in neurological diseases.

The soluble intercellular adhesion molecule-1 (sICAM-1) was measured in paired CSF and serum samples from 128 patients with different neurological diseases. The reference range of blood-derived sICAM-1 fractions in CSF was characterized with reference to the albumin CSF/serum quotients. The low mean concentrations of sICAM-1 of normal controls (n=33) in CSF (1.5 ng/ml; C.V.=40%) compared to serum (285.1 ng/ml; C.V.=32%) indicate that about 60% to 80% of sICAM-1 in normal lumbar CSF derives from blood. This calculation is based on the theoretically expected molecular size-dependent blood-CSF gradient between 300:1 to 250:1. In patients with non-inflammatory diseases (n=21) the sICAM-1 CSF/serum quotient increased non-linearly with increasing albumin CSF/serum quotient (blood-CSF barrier dysfunction) displaying the shape of a saturation-like curve in contrast to hyperbolic curves of other blood-derived proteins in CSF. This non-linear relation between sICAM-1 and albumin quotients does not allow a linear index evaluation reported in earlier studies. In bacterial meningitis (n=31) and viral meningoencephalitis (n=28) in addition to the increased blood-derived fraction, the brain-derived fraction of sICAM-1 in CSF was up to 12-fold higher than that in controls. The sICAM-1 CSF/serum quotients in MS (n=15) did not differ from non-inflammatory controls, i.e., there was no brain-dependent sICAM-1 fluctuation in CSF in contrast to the known fluctuations in blood. Earlier published reports on sICAM-1 have been controversial due to less sensitive assays and unsuitable linear evaluation concepts for blood-CSF barrier dysfunction.

Intrathecal release of sICAM-1 into CSF in neuroborreliosis--increased brain-derived fraction.

In the present study, we report sICAM-1 concentration in the cerebrospinal fluid (CSF) and serum of patients with neuroborreliosis (NB, n = 11), compared to the data from a control group of patients with corresponding blood/CSF barrier dysfunction but without inflammation in the central nervous system (disc prolaps, DP, n = 11). In NB, the sICAM-1 concentration in CSF was increased up to six-fold (ranges: 6.6-42.8 ng/ml and 2.2-9.8 ng/ml for NB and DP respectively) with no change in serum sICAM-1. The corresponding sICAM-1 CSF/serum concentration quotients (Q(ICAM)) were in the ranges: 22.5-171.3 X 10(-3), and 8.8-27.8 X 10(-3) for NB and DP respectively. This finding can be explained by increase of the brain-derived fraction of sICAM-1 in NB. In one case we observed increased Q(ICAM) on 6th day after admission to the hospital (171.3 X 10(-3) at the time of the first lumbar puncture slightly increasing to 243.6 x 10(-3) five days later), followed by normalization, in two remaining repunctured patients we observed decreasing QICAM with normalizing Q(Alb).

Survival of hippocampal neurons in culture upon hypoxia: effect of erythropoietin.

The potential of erythropoietin (EPO) to reduce hypoxia-induced cell death has been investigated in 5-day-old primary cultures of rat postnatal hippocampal neurons. Application of EPO (100 pM) at the start of hypoxia resulted in a significant reduction of neuronal death (33.0 +/- 7.5% in cells incubated with EPO vs 56.75 +/- 7.3% in non-treated cells; n = 4, p < 0.021). Similiar results were obtained upon application of cycloheximide (CHX; 1 microM) simultaneously with hypoxia (34.75 +/- 5.6% vs 56.75 +/- 7.3% with and without CHX, respectively, n = 4, p < 0.035), indicating that hypoxia-induced neuronal death is an active, protein synthesis-dependent process. Both, EPO and EPO receptor (EPOR) were found to be expressed after hypoxia in hippocampal neurons in vitro and in vivo. These results demonstrate for the first time that EPO can reverse hypoxia-induced neuronal death when applied simultaneously with the hypoxic stimulus.

Prothrombin activity and concentration in healthy subjects with and without the prothrombin G20210A mutation.

A common mutation in the prothrombin gene (G20210A) is associated with elevated prothrombin levels and thrombosis. The pathomechanism related to the G20210A mutation is currently not understood and the interdependence of prothrombin activity and prothrombin concentration in plasma is still poorly defined. Six of 191 blood donors examined in the present study carried the prothrombin allele G20210A. Despite the small number of cases, plasma samples from these individuals had significantly higher prothrombin activities than wild type carriers, whereas their prothrombin concentrations-although elevated-did not differ significantly from wild type. In subjects with the G20210A mutation there was also no significant correlation between prothrombin activity and concentration. Analyzing data from healthy blood donors without the prothrombin G20210A mutation, we found only weak correlations between prothrombin activity and concentration of immunoreactive prothrombin. Samples with a relatively high prothrombin concentration but low activity were observed as well as samples with a relatively high activity for a given concentration (hyperactive prothrombin). F1+2 concentrations as indicators of activated coagulation were only elevated in 13 of 125 investigated samples and could not explain any of these findings. Dysfunctional variants of prothrombin, a well known phenomenon, may be responsible for the former, and we speculate that posttranscriptionally modified prothrombin species may explain the observed functional diversity of this factor including hyperactivity. The genotype-phenotype association of the non-coding G20210A mutation is not clear cut. Therefore, further studies are needed to determine which factors apart from the known G20210A polymorphism regulate prothrombin concentration and/or activity and may trigger the manifestation of thrombosis.

Endothelin-1 concentration in plasma is increased after jogging but decreased after cycling in healthy men.

Endothelin-1 plays an important role as a paracrine factor in the regulation of regional blood flow. Plasma levels may represent the net result of spill-over from local stimulation/release and elimination of endothelin-1. In order to compare changes in the concentration of endothelin-1 in the plasma of subjects performing different types of sports exercises we measured immunoreactive endothelin-1 in healthy volunteers ( n=20) performing in random order jogging on a treadmill and cycling on a bicycle ergometer, for 30 min each. Plasma immunoreactive endothelin-1 increased significantly after jogging (2.13+/-0.8 pg/ml versus 2.6+/-0.8 pg/ml, before and after exercise, respectively, P<0.03), whereas it decreased after cycling (2.45+/-0.76 pg/ml versus 2.25+/-0.9 pg/ml, before and after exercise, respectively, P<0.03). We suggest that microtraumatizing effects on the endothelial lining are more pronounced during jogging than during cycling, resulting in a greater increase in plasma endothelin-1, which is too high to be immediately eliminated by the lung despite exercise-induced enhanced pulmonary perfusion. In contrast, similarly enhanced lung perfusion together with a relatively lower stimulation of endothelin-1 compared with jogging, may explain the net decrease in plasma after cycling.

[Patterns of immunoglobulin synthesis in pediatric patients with Coxsackie A9 meningoencephalitis during the neuropathy epidemic in Cuba]. / Patrones de síntesis de inmunoglobulinas en pacientes pediátricos con meningoencefalitis por Coxsackie A9 durante la epidemia de neuropatía en Cuba.

INTRODUCTION: Simultaneously with the origin and development of the Cuban epidemic neuropathy, cases of viral meningoencephalitis with particular characteristics due to Coxsackie were found. This virus and Inoue-Melnick virus were found too in patients suffering from Cuban epidemic neuropathy. PATIENTS AND METHODS: 31 pediatric patients suffering from viral meningoencephalitis were studied. Albumin, IgA, IgM and IgG were quantified in serum and cerebrospinal fluid by nephelometry. Cytochemical studies and reibergrams were performed. RESULTS: There was a lymphocyte predominance in cerebrospinal fluid. A dysfunction of blood-cerebrospinal fluid barrier was shown in 10 patients. Twenty patients have no immunoglobulins intrathecal synthesis. The synthesis patterns were: five patients with local IgM synthesis, two patients with local IgG synthesis and IgA + IgM. IgA + IgG and IgA + IgM pattern was synthesized in one patient respectively. Two patients with low IgG synthesis percentage or IgG intrathecal fractions were reported. CONCLUSIONS: The absence of immunoglobulins intrathecal synthesis and the immunoglobulins synthesis patterns differ from other pediatric patients with enterovirus meningoencephalitis. These patterns may have relationship with modified antigenic characteristics of the virus, also found in Cuban epidemic neuropathy.

[The blood-brain barrier. II. Pathology: brain tumors, brain edema, hypertension, epilepsy]. / Bariera krew-mózg. Czesc II. Patologia--guzy mózgu, obrzek mózgu, nadcisnienie tetnicze, padaczka.

In the first part of the publication the authors presented the blood-brain (BBB) under physiological conditions. The second part includes the current opinions concerning BBB during various disorders of the central nervous system (CNS) and hypertension. The imbalance of BBB is often not only a consequence of a pathologic status, but can be also cause of it. On the other hand BBB influences the therapy of many illnesses by restricting the penetration of drugs to the CNS.

[The blood-brain barrier. I. Histology. Physiology. Embryology. Transport]. / Bariera krew-mózg I. Histologia. Fizjologia. Rozwój embrionalny. Transport.

The concept of blood-brain barrier (bbb) arose in the beginning of the 20th century after report that the dyes injected intravenously did not appear in the brain. The idea and definition of bbb has been changed many times since then. We present current opinion concerning bbb, its histology, embryology, ultrastructure and function on the ground of a review of the recent literature.

[Congenital megaloblastic anemia in a 22-month-old boy]. / Postac dzieciéca niedokrwistosci megaloblastycznej u 22-miesiecznego chlopca.

A 22-month old boy with the congenital form of megaloblastic anaemia is presented. The child was admitted to hospital with moderate-to-severe hematological and neurological symptoms. Very low serum vitamin B12 concentration and normal gastric secretion were determined. A dramatic recovery after intramuscular injections with vitamin B12 was observed.