tau protein in cerebrospinal fluid

Cerebrospinal fluid (CSF) biochemical markers for Alzheimer disease (AD) would be of great value to improve the clinical diagnostic accuracy of the disorder. As abnormally phosphorylated forms of the microtubule-associated protein tau have been consistently found in the brains of AD patients, and since tau can be detected in CSF, two assays based on several well-defined monoclonal tau antibodies were used to study these proteins in CSF. One assay detects most normal and abnormal forms of tau (CSF-tau), while the other is highly specific for phosphorylated tau (CSF-PHFtau). A marked increase in CSF-PHFtau was found in AD (2230±930 pg/mL), as compared with controls (640±230 pg/mL;p<0.0001), vascular dementia, VAD (1610±840 pg/mL;p<0.05), frontal lobe dementia, FLD (1530±1000 pg/mL;p<0.05), Parkinson disease, PD (720±590 pg/mL;p<0.0001), and patients with major depression (230±130 pg/mL;p<0.0001). Parallel results were obtained for CSF-tau. No less than 35/40 (88%) of AD patients had a CSF-PHFtau value higher than the cutoff level of 1140 pg/mL in controls. The present study demonstrates that elevated tau/PHFtau levels are consistently found in CSF of AD patients. However, a considerable overlap is still present with other forms of dementia, both VAD and FLD. CSF-tau and CSF-PHFtau may therefore be useful as a positive biochemical marker, to discriminate AD from normal aging, PD, and depressive pseudodementia. Further studies are needed to clarify the sensitivity and specificity of these assays, including follow-up studies with neuropathological examinations.     

Elevated cerebrospinal fluid SNAP-25 in schizophrenia.

BACKGROUND: Research suggests an association between abnormal exocytosis and schizophrenia. We previously demonstrated increased synaptosomal associated protein, 25 kDa (SNAP-25), a member of the exocytotic mechanism, in the cerebrospinal fluid (CSF) of schizophrenia subjects. In this study, we explored SNAP-25 level and clinical variables in a new group of subjects. METHODS: Twenty-five haloperidol-treated subjects with chronic schizophrenia and twenty-five healthy control subjects participated in the study. Subjects received haloperidol treatment for at least 3 months and then had a lumbar puncture (n = 19). Medication was replaced by placebo, and the lumbar puncture was repeated (n = 25) after 6 weeks or sooner if limited psychotic symptoms occurred. We measured the level of SNAP-25 in the CSF and symptoms with the Brief Psychiatric Rating Scale (BPRS). RESULTS: In both haloperidol (p =.001) and placebo (p =.001) treatment conditions, SNAP-25 was elevated. There was no significant difference in SNAP-25 level between conditions. We identified significant positive correlations among SNAP-25 and the BPRS total score and psychosis and thinking disturbance subscales in subjects on haloperidol. CONCLUSIONS: These observations confirm our previous report of elevated CSF SNAP-25 and suggest that synaptic pathology may be linked with the pathophysiology of schizophrenia.     

Serum and cerebrospinal fluid antibodies to cytomegalovirus in schizophrenia

Antibodies to cytomegalovirus (CMV) were determined in the serum and cerebrospinal fluid (CSF) by complement-fixing (CF), enzyme immunoassay (EIA), and enhanced virus neutralization test (EVNT), in acute unmedicated schizophrenic patients and neurological controls. An elevated level of CF antibody was observed in three serum specimens from the schizophrenic patients and in one control specimen. No CF antibody was present in the CSF samples of the two patient groups tested. By EIA none of the serum or CSF specimens was positive for IgM antibody to CMV. By EVNT, 17% of the schizophrenic patients exhibited a CSF/serum ratio greater than 2 SD, whereas the corresponding figure for the control group was 4% (P greater than 0.05). The role of CMV in the etiopathogenesis of schizophrenia is discussed in the light of the present and previous negative findings.     

精神分裂症患者脑脊液中神经元特异性烯醇化酶和髓鞘碱性蛋白的研究

目的 探讨精神分裂症患者是否有脑损伤。方法 对33例精神分裂症患者和9例对照组手术病人的脑脊液（CSF）中神经元特异性烯醇化酶（NSE）和髓鞘碱性蛋白（MBP）采用双抗体夹心酶联法测定。结果 病例组的NSE的含量与对照组比较有显著性差异（P<0.01）。病例组脑脊液中NSE和MBP的含量呈正相关。结论　提示精神分裂症患者有脑损伤。     

Abnormal cerebrospinal fluid plasma cells in a case of myeloma

Cerebrospinal fluid (CSF) involvement in myeloma is rarely seen. Recently we experienced a case with this lesion. A 70-year-old man developed consciousness level disorder during the course of bronchopneumonia. Neurological examination revealed stuporous consciousness, neck stiffness and Kernig's sign. Immunoelectrophoresis showed monoclonal IgG in serum. CSF which was obtained through lumbar puncture was clear and its pressure was 155 mm H2O. It contained 207 white cells/3 mm3; glucose, 54 mg/dl; and protein, 33 mg/dl. The differential count of the CSF was (in %) monocytes, 48.0; plasma cells, 25.5; neutrocytes, 15.5; and lymphocytes, 11.0. Cytoplasm and nucleus of the plasma cells were in various sizes. Some irregular multiple nuclei, flaming cells and grape cells were also observed in them. The cytoplasm of the plasma cells fluoresced with antisera against lambda chains IgG. The value of immunofluorescent technique in identifying plasma cells in the CSF is emphasized.     

Thiobarbituric acid reactive substances in the cerebrospinal fluid in schizophrenia

Increased levels of lipid peroxidation products (thiobarbituric acid reactive substances [TBARS]) are reported in plasma/serum from patients with schizophrenia. CSF TBARS levels were assessed in 10 neuroleptic-free patients with schizophrenia and in 9 normal controls. Controlling for duration of storage, CSF TBARS content was significantly lower in patients with schizophrenia vs. controls (p<0.002). No significant correlations were found between CSF TBARS and patients' age, gender, or duration of illness. The likely source of reported elevated plasma/serum TBARS in schizophrenia is therefore in the periphery. Degeneration of central neuronal membranes in schizophrenia is not supported by the present study.     

Regional specificity of cerebrospinal fluid abnormalities in first episode schizophrenia

The timing and regional specificity of cerebrospinal fluid (CSF) enlargements have not been well described in schizophrenia. High-resolution magnetic resonance images and computational image analysis methods were used to localize cross-sectional changes in lateral ventricle and sulcal and subarachnoid CSF in first episode schizophrenia patients (51 males/21 females) and healthy subjects (37 males/41 females). Volumes were obtained for each lateral ventricle horn and regional differences identified by comparing the distances from the ventricular surfaces to the central core at anatomically matched locations. Extra-cortical CSF differences were compared by measuring the proportion of CSF voxels sampled from spatially homologous cortical surface points. Significant extra-cortical CSF enlargements were observed in first episode patients, where regional differences surrounded the temporal, anterior frontal and parietal cortices. Volume and ventricular surface analyses failed to show significant effects of diagnosis. However, interactions indicated dorsal superior horn expansions in female patients compared with same-sex controls. Since ventricular enlargements are widely reported in chronic patients, our observations at first episode suggest ventricular enlargement may progress after disease onset with early changes occurring around the dorsal superior horn. In contrast, sulcal and subarachnoid CSF increases may be manifest near or before the first episode but after brain development is complete, reflecting pronounced reductions in proximal brain tissue.     

Myelin basic protein in cerebrospinal fluid in neurocysticercosis

Cerebrospinal fluid (CSF) from 115 patients with several neurological disorders were tested for the presence of myelin basic protein (MBP), fragment P1 43-88. Cases were divided into groups according to neurological diagnosis. The control group (50 patients with chronic headache) presented normal CSF composition and presented no evidence of the presence of MBP. MBP was found in: four cases of the 44 of neurocysticercosis; three of the 8 cases of multiple sclerosis; one case of schistosomiasis with spinal cord involvement. Neuroimmunological data are discussed considering results found in this investigation.     

Increased cerebrospinal fluid cyclo(His-Pro) content in schizophrenia.

Cyclo(His-Pro) (CHP) is a peptide endogenous to human brain and cerebrospinal fluid (CSF). In animal studies administration of exogenous CHP augments dopaminergic neurotransmission. To explore the role of this peptide in schizophrenia, a disease characterized by a hyperdopaminergic state, we have measured CSF CHP levels in control, never-medicated schizophrenics and medicated schizophrenics. Our data show a 53% increase in CSF levels of CHP in never-medicated schizophrenics (p = 0.015), and a 25% increase in medicated schizophrenics when compared to controls. We speculate that CHP may contribute to the expression of hyperdopaminergic symptoms in schizophrenia.     

Increased cerebrospinal fluid tau protein in multiple sclerosis

Axonal damage is now being recognized as a common finding in multiple sclerosis (MS) lesions and a cause of irreversible neurological damage. Attempts to identify markers of early axonal damage are of great significance. This prompted us to examine the microtubule-associated protein tau in the cerebrospinal fluid (CSF) of patients with MS vs. controls. Tau was measured by double antibody sandwich ELISA. Increased CSF tau levels were found in MS as compared to controls (medians 249.6 and 135 pg/ml respectively, p<0.001). Half of the MS patients presented with levels above the upper limit of the controls. A significant increase vs. controls was found in both relapsing-remitting and progressive subtypes. These data may indicate axonal impairment in a subpopulation of MS patients and may provide a tool for the estimation of axonal damage during life.     

Increased cerebrospinal fluid protein tau concentration in neuro-AIDS

OBJECTIVES: Assessment of cerebrospinal fluid (CSF) levels of protein tau in human immunodeficiency virus type 1 (HIV-1) infection. MATERIAL AND METHODS: CSF tau levels were analyzed in 52 HIV-1-infected patients, 37 of whom had no neurological symptoms, eight had aquired immunodeficiency syndrome (AIDS) dementia complex (ADC), and seven had AIDS with other neurological complications. RESULTS: A significantly higher mean CSF tau concentration was found in patients with ADC (380 pg/ml) compared with patients with neuroasymptomatic HIV-1 infection (120 pg/ml, P<0.01) and HIV-negative controls (150 pg/ml, P<0.05). No difference in CSF tau levels was found between patients with ADC and patients with AIDS with other neurological complications. CONCLUSION: CSF tau might be used as a biochemical marker for axonal degeneration and might be of use to identify HIV-1-infected patients with ADC and other neurological complications, but it cannot discriminate between ADC and other neurological complications in HIV-1-infection.     

Studies on protein methyltransferase in human cerebrospinal fluid

Protein methyltransferases, rich in most mammalian brains, were studied in human cerebrospinal fluid (CSF). Among several well-characterized groups of methyltransferases, protein methylase I (S-adenosylmethionine:protein-arginine N-methyltransferase, EC 2.1.1.23) was found in significant amounts in human CSF samples. Both myelin basic protein (MBP) -specific and histone-specific protein methylase I activities were observed, the latter being generally higher in most CSF. S-Adenosyl-L-homocysteine, a potent product inhibitor for the methyltransferase, inhibited approximately 90% of MBP-specific protein methylase I activity at a concentration of 1 mM. The optimum pH of the MBP-specific protein methylase I was found to be around 7.2. Identity of exogenously added MBP as the methylated substrate for CSF enzyme was confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. An amino acid analysis of the [methyl-3H]protein hydrolysate showed two major radioactive peaks cochromatographing with monomethyl- and dimethyl (symmetric)-arginine. Human CSF contained relatively high endogenous protein methylase I activity (activity measured without added substrate protein): The endogenous substrate can be immunoprecipitated by antibody raised against calf brain MBP. Finally, CSF from several neurological patients were analyzed for protein methylase I, and the results are presented.