An amyloid beta vaccine that safely drives immunity to a key pathological species in Alzheimer's disease: pyroglutamate amyloid beta.

Pyroglutamate amyloid beta3-42 (pGlu-Abeta3-42), a highly amyloidogenic and neurotoxic form of Abeta, is N-terminally truncated to form a pyroglutamate and has recently been proposed as a key target for immunotherapy. Optimized ACI-24, a vaccine in development for the treatment and prevention of Alzheimer's disease, focuses the antibody response on the first 15 N-terminal amino acids of Abeta (Abeta1-15). Importantly, clinical data with an initial version of ACI-24 incorporating Abeta1-15, established the vaccine's safety and tolerability with evidence of immunogenicity. To explore optimized ACI-24's capacity to generate antibodies to pGlu-Abeta3-42, pre-clinical studies were carried out. Vaccinating mice and non-human primates demonstrated that optimized ACI-24 was well-tolerated and induced an antibody response against Abeta1-42 as expected, as well as high titres of IgG reactive with pyroGlu-Abeta. Epitope mapping of the polyclonal response confirmed these findings revealing broad coverage of epitopes particularly for Abeta peptides mimicking where cleavage occurs to form pGlu-Abeta3-42. These data are in striking contrast to results obtained with other clinically tested Abeta targeting vaccines which generated restricted and limited antibody diversity. Taken together, our findings demonstrate that optimized ACI-24 vaccination represents a breakthrough to provide a safe immune response with a broader Abeta sequence recognition compared to previously tested vaccines, creating binders to pathogenic forms of Abeta important in pathogenesis including pGlu-Abeta3-42.

Progression of prodromal motor and non-motor symptoms in the premotor phase study - 2-year follow-up data.

BACKGROUND AND PURPOSE: The neuropathological process starts years before the diagnosis of Parkinson's disease (PD). Assessment of prodromal features in healthy individuals may help to define those with high risk for future PD. Our aim was to evaluate the presence and progression of prodromal markers in individuals with low risk [healthy controls (HC), n = 14] and high risk for PD (HR-PD, n = 34) and early PD (n = 14) patients. METHODS: Several risk or prodromal markers were combined to define HR-PD. Other prodromal markers were followed in 6-month intervals for 2 years. As recommended by the Movement Disorder Society Task Force, likelihood ratios (LRs) of markers, motor scores and PD probability scores were calculated and compared. RESULTS: The baseline LR for non-motor prodromal markers was significantly higher in PD and HR-PD compared to HC. Within 2 years, changes in these LRs did not significantly differ between the groups. Motor worsening was significant only in the PD group (50% of the patients) against HR-PD (15%) and HC (7%). Change in the non-motor prodromal LR did not significantly correlate with motor worsening, but higher baseline non-motor LRs were associated with Unified Parkinson's Disease Rating Scale III values at 2 years of follow-up. CONCLUSIONS: Our study shows that the frequency of non-motor prodromal markers is higher in the HR-PD group but does not increase within 2 years. The progression of motor and non-motor markers seems to be independent, but higher baseline non-motor burden is associated with the motor status after 2 years. Moreover, our data argue for a high impact of motor markers in the risk estimation for future PD.

The nicotinergic receptor as a target for cognitive enhancement in schizophrenia: barking up the wrong tree?

RATIONALE: Cognitive symptoms have increasingly been recognized as an important target in the development of future treatment strategies in schizophrenia. The nicotinergic neurotransmission system has been suggested as a potentially interesting treatment target for these cognitive deficits. However, previous research yielded conflicting results, which may be explained by several methodological limitations, such as the failure to include both a group of smoking and non-smoking schizophrenic patients, the use of only a single nicotine dose, and the inclusion of a very limited cognitive battery. OBJECTIVES: The present study aims at investigating the cognitive effects of nicotine in schizophrenia while addressing these methodological issues. METHODS: In a double-blind placebo-controlled randomized crossover design, cognitive effects are assessed in smoking (n =16) and non-smoking (n =16) schizophrenic patients after receiving active (1 or 2 mg) or placebo oromucosal nicotine spray. RESULTS: A modest improving effect of nicotine on attention in the smoking but not the non-smoking group was found. No enhancing effects were found on measures of visual memory, working memory, processing speed, psychomotor speed, or social cognitive functioning in either patient group. CONCLUSIONS: These findings suggest that the nicotinic receptor only has limited value as a cognitive treatment target in schizophrenia.

Transgenic animal models of Alzheimer's disease and related disorders: histopathology, behavior and therapy.

Alzheimer's disease (AD) is a devastating neurodegenerative disease that affects more than 15 million people worldwide. Within the next generation, these numbers will more than double. To assist in the elucidation of pathogenic mechanisms of AD and related disorders, such as frontotemporal dementia (FTDP-17), genetically modified mice, flies, fish and worms were developed, which reproduce aspects of the human histopathology, such as beta-amyloid-containing plaques and tau-containing neurofibrillary tangles (NFT). In mice, the tau pathology caused selective behavioral impairment, depending on the distribution of the tau aggregates in the brain. Beta-amyloid induced an increase in the numbers of NFT, whereas the opposite was not observed in mice. In beta-amyloid-producing transgenic mice, memory impairment was associated with increased levels of beta-amyloid. Active and passive beta-amyloid-directed immunization caused the removal of beta-amyloid plaques and restored memory functions. These findings have since been translated to human therapy. This review aims to discuss the suitability and limitations of the various animal models and their contribution to an understanding of the pathophysiology of AD and related disorders.

Genetic association of acyl-coenzyme A: cholesterol acyltransferase with cerebrospinal fluid cholesterol levels, brain amyloid load, and risk for Alzheimer's disease.

A common polymorphism of the gene encoding acyl-coenzyme A: cholesterol acyltransferase 1 (SOAT1), which is involved in the regulation of beta-amyloid peptide generation, is associated with low brain amyloid load (P=0.03) and with low cerebrospinal fluid levels of cholesterol (P=0.005). This polymorphism of SOAT1 is also associated with reduced risk for Alzheimer's disease in ethnically distinct populations (P=0.0001, odds ratio: 0.6, 95% confidence interval 0.4-0.8).

Saitohin gene is not associated with Alzheimer's disease.

BACKGROUND: The deposition of tau protein in neurofibrillary tangles constitutes an important feature of many neurodegenerative disorders, including Alzheimer's disease. A polymorphic gene, saitohin (STH), nested within the tau gene (microtubule associated protein tau, MAPT), was recently identified and an association of a non-synonymous polymorphism in STH with increased risk for Alzheimer's disease was suggested. OBJECTIVE AND METHODS: To test the above hypothesis in a case-control association study of two independent white populations within Switzerland and Greece, comparing genotype and allele frequencies from 225 Alzheimer's disease patients and 144 healthy control subjects. RESULTS: No differences in allelic or genotypic distributions between Alzheimer's disease patients and controls was found in the individual samples (Swiss/Greek) or in the combined sample. Stratification for the presence of apolipoprotein E (APOE) epsilon 4 allele, sex, or age did not show significant effects in the populations studied, nor was there an effect on the age of onset. CONCLUSIONS: No evidence was found for an association of the non-synonymous polymorphism (Q7R) in STH and Alzheimer's disease. This finding is in line with earlier studies showing no association between MAPT and Alzheimer's disease.

Response of radiochemotherapy-associated cerebral edema to a phytotherapeutic agent, H15.

Twelve patients with brain tumors and progressive edema caused by tumor progression or radiochemotherapy-related leukoencephalopathy were treated with H15, a phytotherapeutic anti-inflammatory agent. Edema was reduced in two of seven patients with glioblastoma with tumor progression and in three of five patients with treatment-related leukoencephalopathy. All patients with leukoencephalopathy improved clinically for several months.

Preirradiation gemcitabine chemotherapy for newly diagnosed glioblastoma. A phase II study.

BACKGROUND: The median survival for patients with glioblastoma is reported to be 12 months. To improve the outcome for glioblastoma patients, the authors evaluated the therapeutic efficacy of preirradiation gemcitabine chemotherapy followed by standard radiotherapy. METHODS: Twenty-one patients with newly diagnosed glioblastoma were enrolled in a prospective unicenter trial of preirradiation gemcitabine chemotherapy. Chemotherapy included up to 4 monthly cycles of intravenous gemcitabine (Day 1, Day 8, and Day 15; 1000 mg/m2). Involved field radiotherapy was given after chemotherapy or earlier in the case of disease progression or gemcitabine intolerance. RESULTS: With gemcitabine chemotherapy alone, there was a median progression free survival of 11 weeks and a progression free survival rate at 4 months of 24%. In 18 of 21 patients who subsequently received a full course of radiotherapy, the median progression free survival from the time of diagnosis was 8 months and the progression free survival rate at 12 months was 17% (3 of 18 patients). The median overall survival was 11 months. There was no specific treatment-related neurotoxicity reported. Neither age nor extent of residual postoperative tumor predicted the duration of progression free survival in patients treated with gemcitabine chemotherapy alone or in those treated with gemcitabine plus radiotherapy. CONCLUSIONS: Gemcitabine followed by radiotherapy is a safe regimen for patients with newly diagnosed glioblastoma but the gemcitabine schedule used in the current study did not appear to confer any survival advantage compared with standard involved field radiotherapy alone.

A role for preirradiation PCV chemotherapy for oligodendroglial brain tumors.

Oligodendroglial tumors have been identified as a subgroup of glial neoplasms with a distinctly better response to chemotherapy and overall survival than purely astrocytic gliomas. Here we report our experience with adjuvant postirradiation and preirradiation chemotherapy using procarbazine, lomustine, and vincristine (PCV) in 27 patients with WHO grade II or III oligodendroglioma or oligoastrocytoma. The efficacy of chemotherapy was assessed according to the Macdonald response criteria (complete response, CR; partial response, PR; stable disease, SD; progressive disease, PD) and progression-free survival intervals by computed tomography or magnetic resonance imaging. First, we confirm that PCV salvage therapy for patients progressing after radiotherapy is highly effective (n = 11, 1 CR, 5 PR, 5 SD; median progression-free survival has not yet been reached, but is longer than 18 months). Second, 3 patients who received radiotherapy plus PCV as first-line therapy achieved CR and 2 achieved SD, and all 5 are progression-free with a median follow-up of 12 months. Third, given these encouraging results, 11 patients received postoperative preirradiation PCV chemotherapy and were given radiotherapy only upon progression. Preirradiation PCV chemotherapy was also effective (2 CR, 3 PR, 6 SD; median progression-free survival has not been yet reached, but is longer than 14 months). Patients with anaplastic oligoastrocytomas were as likely to respond to PCV chemotherapy, as were patients with anaplastic oligodendroglioma. Three patients who had previously responded to PCV were successfully treated with a second course of PCV upon recurrence. PCV chemotherapy was also effective in patients with leptomeningeal spread of oligodendrogliomas. A randomized prospective trial is required to compare the effectiveness and neurotoxicity of first-line PCV chemotherapy followed by radiotherapy to the traditional reverse sequence.

Evidence for a constitutive, verapamil-sensitive, non-P-glycoprotein multidrug resistance phenotype in malignant glioma that is unaltered by radiochemotherapy in vivo.

Human malignant gliomas are commonly resistant to chemotherapy. Here, we examined the role of the multidrug resistance (mdr) mechanism in the chemo-resistance of these tumors, using a twofold approach: (i) by assessing a possible mdr phenotype before and after chronic drug exposure of glioma cells in vitro, and (ii) by assessing the modulation of expression of the mdr-associated P-glycoprotein (Pgp) using radiotherapy and serial cycles of chemotherapy in human glioblastoma patients in vivo. T98G, and to a lesser degree, LN-229 human malignant glioma cells exhibit a constitutive mdr phenotype as determined by the modulation of dye transport and by the augmentation of chemosensitivity by the mdr antagonist, verapamil. Thus, coexposure to verapamil enhances the cytotoxicity of vincristine, doxorubicin and VM26 in T98G cells and that of vincristine in LN-229 cells. Chronic exposure of the cells to low concentrations of vincristine and doxorubicin, but not VM26, topotecan or BCNU, moderately enhances the mdr-like phenotype, as assessed by drug expulsion assays. However, chronic exposure to increasing drug concentrations does not significantly alter the sensitivity to the respective drugs. These data are consistent with a constitutive, but not drug-inducible, mdr-like drug resistance in glioma cells in vitro. Immunocytochemical analysis of human malignant gliomas in vivo reveals that Pgp expression is more abundant in endothelial cells within the gliomas, than in the glioma cells proper. Importantly, Pgp expression is unaltered by radiochemotherapy, assessed by comparative immunocytochemistry of glioma specimens obtained serially before and after radiochemotherapy. We conclude that (i) glioma cells exhibit constitutive mdr-like drug resistance that is not significantly altered by chronic drug exposure in vitro; (ii) endothelial cells may play an important role in Pgp-mediated drug resistance of gliomas in vivo; (iii) radiotherapy and repeated chemotherapy cycles do not modulate Pgp expression in human malignant gliomas in vivo; (iv) there is preliminary evidence for a non-Pgp, verapamil-sensitive drug transport activity in glioma cells.

Antiapoptotic Bcl-2 family protein expression increases with progression of oligodendroglioma.

BACKGROUND: Altered expression of Bcl-2 family proteins has been associated with tumorigenesis and tumor progression as well as resistance to radiotherapy and chemotherapy. In the current study, Bcl-2 family protein expression was examined in oligodendrogliomas and anaplastic oligodendrogliomas, and an attempt was made to determine whether these proteins accumulate during disease progression and to search for protein expression patterns predictive of time to progression and overall survival. METHODS: A total of 42 oligodendroglioma tissue samples, 26 de novo World Health Organization (WHO) Grade 2 oligodendrogliomas, and 16 de novo WHO Grade 3 anaplastic oligodendrogliomas were studied. Nineteen Grade 2 tumors progressed: 10 again were Grade 2 oligodendrogliomas and 8 had progressed to higher grade lesions. Eight anaplastic oligodendrogliomas progressed: five again were WHO Grade 3 tumors and three were glioblastoma multiforme. Expression of Bcl-2, Bax, Bcl-X, and Mcl-1 proteins and of the proliferation marker Ki-67 was evaluated by immunohistochemistry. Apoptotic cells were quantified by in situ nick translation (ISNT). RESULTS: De novo WHO Grade 2 oligodendrogliomas had higher Bcl-2 scores (P = 0.037), lower MIB-1 scores (P = 0.0012), and lower ISNT scores (P = 0.049) compared with de novo WHO Grade 3 anaplastic oligodendrogliomas. In de novo oligodendrogliomas, low numbers of Bax positive cells were associated with a short time to disease progression (P = 0.043). In de novo anaplastic oligodendrogliomas, low numbers of Bcl-2 positive cells correlated with short survival (P = 0.029). In tumors that had progressed from WHO Grade 3 anaplastic oligodendrogliomas, the authors found significantly more Bcl-X positive (P = 0.005), Mcl-1 positive (P = 0.002), and Bax positive (P = 0.03) cells. CONCLUSIONS: The results of the current study show that progression of oligodendrogliomas and anaplastic oligodendrogliomas is associated with an enhanced expression of antiapoptotic Bcl-2 family proteins.

BCL-2 family protein expression in initial and recurrent glioblastomas: modulation by radiochemotherapy.

OBJECTIVE: In vitro studies indicate a role of apoptosis regulatory proteins of the BCL-2 family in the resistance of glioblastoma multiforme to irradiation and chemotherapy. To date, no study has compared the expression of these proteins in initial and recurrent tumours. The differences of expression of BCL-2, BCL-X, BAX, and MCL-1 proteins of paired first resection and recurrence glioblastoma specimens were examined. METHODS: Immunohistochemistry was performed in 37 cases of glioblastoma multiforme with paraffin embedded tissue from first resections and their recurrences in three treatment groups (15 radiochemotherapy, 15 irradiation, seven untreated). Ten high power fields were evaluated with an arbitrary score (< 5%=1, 5-50%=2, >50%=3), and cumulative scores for each antigen calculated. RESULTS: In the whole group, we found a significant up regulation of antiapoptotic BCL-2 (median cumulative score of 15 in the primary, 19 at recurrence; p<0.0001 in the Wilcoxon test), BCLX (median scores 20 and 25, respectively, p<0.0001), and MCL-1 (median scores 11 and 14, p=0.0395), and a significant down regulation of proapoptotic BAX (median scores 14 and 11, p<0.0001). In the subgroups, these trends were also found. No association between protein expression and treatment regimen was found, although significant changes were restricted to the subgroups that received adjuvant chemotherapy. No significant correlation with clinical prognosis was detected with the Kaplan-Meier method. CONCLUSIONS: In the development from initial to recurrent glioblastoma multiforme, the BCL-2 family rheostat shifts towards antiapoptotic adjustment in vivo. Importantly, the changes in BCL-2 family protein expression characterised here were also seen in the subgroup of patients who did not receive adjuvant radiotherapy or chemotherapy, suggesting that the changes of BCL-2 family protein expression result not only from radiochemotherapy but also reflect the natural course of disease.

Patterns of cyclooxygenase-1 and -2 expression in human gliomas in vivo.

Cyclooxygenases (COX, prostaglandin endoperoxide synthases, PGG/H synthases) are potent mediators of inflammation. While COX-1 is constitutively expressed in a wide range of tissues, COX-2 is cytokine inducible. Although COX-1 expression is observed in normal tissue, enhanced COX-2 expression has been attributed a key role in the development of edema, impeding blood flow and immunomodulation observed in pathologically altered tissues. Here, we have analyzed the expression of COX-1 and COX-2 in 50 gliomas and 10 control brains with no neuropathological alterations by immunohistochemistry; 22 glioblastoma multiforme, 9 anaplastic astrocytomas, 5 protoplasmic astrocytomas, 1 gemistocytic astrocytoma and 13 fibrillary astrocytomas were included in the study. Compared with control brains, accumulation of COX-1 was detected in 20-50% of all cells in both low- and high-grade gliomas. Double-labeling experiments revealed COX-1 expression in subsets of macrophages/microglial cells within the tumor parenchyma and in areas of infiltrative tumor growth. Of the COX-1-positive cells, 90% expressed MHC class II antigens. No COX-1 immunoreactivity was observed in tumor cells. COX-2-positive cells accumulated in tumor cells and in single macrophages/microglial cells in the immediate vicinity of necroses. Further studies are required to determine whether COX-2 is involved in the development of necrosis or, more likely, whether COX-2 is a part of the tumor tissue response to necrosis.

Topotecan-based combination chemotherapy for human malignant glioma.

BACKGROUND: Topotecan has been considered a promising agent for the adjuvant chemotherapy of human malignant glioma because of its novel mode of action, its activity against other solid tumors, and its good penetration across the blood-brain barrier. However, the clinical effects of topotecan monotherapy in malignant glioma have been disappointing. MATERIALS AND METHODS: We sought to identify suitable partners for topotecan combination chemotherapy of malignant glioma using two well-characterized human malignant glioma cell lines, T98G and LN-229. The effects of co-exposure to topotecan and other chemotherapy drugs were assessed in cytotoxic and clonogenic cell death assays. RESULTS: We found additive, less-than-additive, or occasional antagonistic effects, but never synergistic activity of topotecan with either CCNU, VM26 or vincristine, in acute cytotoxicity or in clonogenic cell death assays, with simultaneous or sequential drug exposure. VM26 or vincristine followed by topotecan yielded the most favourable results. Further, prolonged exposure of the glioma cells to topotecan and either CCNU, VM26, vincristine, cisplatin, doxorubicin or cytarabine resulted in additive but not synergistic growth inhibition. CONCLUSIONS: The present study fails to identify a specific partner for topotecan-based combination chemotherapy of malignant glioma among the chemotherapeutic drugs examined here. While this does not exclude a possible synergy of the drug combinations examined here in vivo, a focus on novel partners for topotecan or topotecan-based chemoimmunotherapy may be more promising.

Selective potentiation of drug cytotoxicity by NSAID in human glioma cells: the role of COX-1 and MRP.

Here, we report that nonsteroidal anti-inflammatory drugs (NSAID) enhance the cytotoxic effects of doxorubicin and vincristine in T98G human malignant glioma cells. The cytotoxicity of BCNU, cisplatin, VM26, camptothecin, and cytarabine is unaffected by NSAID. No free radical formation is induced by doxorubicin or vincristine in the absence or presence of NSAID. Doxorubicin and vincristine cytotoxicity in the absence or presence of NSAID are unaffected by free radical scavengers. Functional inhibitors of phospholipase A2 (PLA2), such as dexamethasone and quinacrine, do not mimick the effects of NSAID. T98G cells, but not LN-18, LN-229, LN-308, or A172 glioma cells, express cyclooxygenase (COX-1) and NSAID do not modulate drug cytotoxicity in the other cell lines, except T98G. Thus, augmentation of doxorubicin and vincristine cytotoxicity by NSAID correlates with COX-1 expression. However, ectopic expression of COX-1 in LN-229 cells does not induce the phenotype of T98G cells, indicating that COX-1 inhibition does not mediate the effects of NSAID on drug cytotoxicity. In contrast, a multidrug resistance (MDR) phenotype due to expression of the multidrug resistance-associated protein (MRP) is most prominent in T98G cells and is amenable to modulation by indomethacin, suggesting that inhibition of MRP is at least in partly responsible for the potentiation of doxorubicin and vincristine cytotoxicity by NSAID.

Gemcitabine cytotoxicity of human malignant glioma cells: modulation by antioxidants, BCL-2 and dexamethasone.

Gemcitabine is a novel antimetabolite drug that acts by multiple mechanisms, including inhibition of ribonucleoside diphosphate reductase, of dCMP deaminase and of dCTP incorporation into DNA and RNA. Here, we report that gemcitabine induces cytotoxic and clonogenic death of 12 human malignant glioma cell lines at clinically relevant concentrations around 1 microM. Gemcitabine is thus approximately 100-fold more active than the congener drug, cytarabine. Gemcitabine cytotoxicity of glioma cells does not require wild-type p53 activity: (i) there was no difference in the susceptibility to gemcitabine between cell lines with wild-type p53 and cell lines with mutant or deleted p53; (ii) ectopic expression of a temperature-sensitive p53 protein either at wild-type (32.5 degrees C) or at mutant (38.5 degrees C) conformation had no significant influence on gemcitabine-induced cell death. Gemcitabine cytotoxicity was unaffected by the antioxidants, N-acetylcysteine and phenyl-N-tert-butyl-alpha-phenylnitrone. There was no correlation between the susceptibility to gemcitabine and the endogenous expression of the B cell lymphoma-2 (BCL-2)-family proteins BCL-2, BCL-XL, myeloid cell leukemia-1 (MCL-1), BCL-2-associated X protein (BAX), BCL-2 homologous antagonist/killer (BAK) and BCL-XS. Ectopic expression of BCL-2 moderately attenuated gemcitabine-induced cell death. Similarly, preexposure to the synthetic steroid, dexamethasone, which is commonly used to control cerebral edema in brain tumor patients, reduced gemcitabine cytotoxicity. We conclude that the clinical evaluation of gemcitabine for the adjuvant chemotherapy of malignant glioma is warranted.

Irradiation induced clonogenic cell death of human malignant glioma cells does not require CD95/CD95L interactions.

BACKGROUND: Radiotherapy is the single most effective therapy for malignant gliomas. Targeting the CD95 apoptotic pathway is a promising experimental approach to these neoplasms. Here, we asked whether irradiation modulates CD95-mediated apoptosis of human malignant glioma cells in vitro. MATERIALS AND METHODS: LN-18, LN-229 and T98G human malignant glioma cell lines were irradiated with dosages from 0-8 Gy and treated with CD95L (CD95 ligand). CD95 expression was assessed by flow cytometry. Caspase activity was determined by DEVD cleavage. Cytotoxic effects were assessed by crystal violet staining of cells in a 96-well plate assay. Clonogenic cell death was determined by a standard colony forming assay. RESULTS: We find that (i) CD95L-induced apoptosis, but not irradiation-induced clonogenic cell death, involves caspase 3 activation and is blocked by the viral caspase inhibitor, crm-A. (ii) Irradiation does not modulate CD95 expression either in p53 wild-type or in p53 mutant glioma cell lines, and does not enhance CD95L-evoked caspase 3 activity or CD95L-induced clonogenic cell death. CONCLUSIONS: We conclude that endogenous CD95/CD95L interactions are not involved in radiation-induced clonogenic cell death and that the killing cascades of CD95L and irradiation are independent in human malignant glioma cells.

Soluble CD95 (Fas/APO-1) in malignant glioma: (no) implications for CD95-based immunotherapy?

CD95 targeting is a novel approach of immunotherapy for malignant glioma that might be antagonized by the release of soluble CD95 by the tumor cells. An alternatively spliced CD95 mRNA that encodes a secreted CD95 variant has been detected in glioma cell lines in vitro and in human tumors in vivo. Here, we report that the levels of soluble CD95 in the serum of malignant glioma patients do not differ from those of lumbar disk disease patients. Soluble CD95 was detected in the CSF in 2 of 20 malignant glioma patients by ELISA. Bioassay studies indicate that these low levels of soluble CD95 in the CSF of some patients with malignant glioma cells are unlikely to interfere with CD95-based immunotherapy of malignant gliomas in vivo.