Patrizia Sola

Exome Sequencing Reveals VCP Mutations as a Cause of Familial ALS

Using exome sequencing, we identified a p.R191Q amino acid change in the valosin-containing protein (VCP) gene in an Italian family with autosomal dominantly inherited amyotrophic lateral sclerosis (ALS). Mutations in VCP have previously been identified inxa0families with Inclusion Body Myopathy, Paget disease, and Frontotemporal Dementia (IBMPFD). Screening of VCP in a cohort of 210 familial ALS cases and 78 autopsy-proven ALS cases identified four additional mutations including a p.R155H mutation in a pathologically proven case of ALS. VCP protein is essential for maturation of ubiquitin-containing autophagosomes, and mutant VCP toxicity is partially mediated through its effect on TDP-43 protein, a major constituent of ubiquitin inclusions that neuropathologically characterize ALS. Our data broaden the phenotype of IBMPFD to include motor neuron degeneration, suggest that VCP mutations may account for ∼1%-2% of familial ALS, and provide evidence directly implicating defects in the ubiquitination/protein degradation pathway in motor neuron degeneration.

A two-stage genome-wide association study of sporadic amyotrophic lateral sclerosis

The cause of sporadic amyotrophic lateral sclerosis (ALS) is largely unknown, but genetic factors are thought to play a significant role in determining susceptibility to motor neuron degeneration. To identify genetic variants altering risk of ALS, we undertook a two-stage genome-wide association study (GWAS): we followed our initial GWAS of 545 066 SNPs in 553 individuals with ALS and 2338 controls by testing the 7600 most associated SNPs from the first stage in three independent cohorts consisting of 2160 cases and 3008 controls. None of the SNPs selected for replication exceeded the Bonferroni threshold for significance. The two most significantly associated SNPs, rs2708909 and rs2708851 [odds ratio (OR) = 1.17 and 1.18, and P-values = 6.98 x 10(-7) and 1.16 x 10(-6)], were located on chromosome 7p13.3 within a 175 kb linkage disequilibrium block containing the SUNC1, HUS1 and C7orf57 genes. These associations did not achieve genome-wide significance in the original cohort and failed to replicate in an additional independent cohort of 989 US cases and 327 controls (OR = 1.18 and 1.19, P-values = 0.08 and 0.06, respectively). Thus, we chose to cautiously interpret our data as hypothesis-generating requiring additional confirmation, especially as all previously reported loci for ALS have failed to replicate successfully. Indeed, the three loci (FGGY, ITPR2 and DPP6) identified in previous GWAS of sporadic ALS were not significantly associated with disease in our study. Our findings suggest that ALS is more genetically and clinically heterogeneous than previously recognized. Genotype data from our study have been made available online to facilitate such future endeavors.

Could mitochondrial haplogroups play a role in sporadic amyotrophic lateral sclerosis

Mitochondrial impairment has been implicated in the pathogenesis of the amyotrophic lateral sclerosis (ALS). Furthermore, mitochondrial-specific polymorphisms were previously related to other neurodegenerative diseases, such as Parkinson, Friedreich and Alzheimer disease. To investigate if specific genetic polymorphisms within the mitochondrial genome (mtDNA) could act as susceptibility factors and contribute to the clinical expression of sporadic ALS (sALS), we have genotyped predefined European mtDNA haplogroups in 222 Italian patients with sALS and 151 matched controls. Individuals classified as haplogroup I demonstrated a significant decrease in risk of ALS versus individuals carrying the most common haplogroup, H (odds ratio 0.08, 95% confidence interval 0.04-0.4, p < 0.01). Further stratification of the dataset by sex, age and site of onset of disease and survival failed to reach significance for association. Our study provides evidence of the contribution of mitochondrial variation to the risk of ALS development in Caucasians. Further it may help elucidate the mechanism of the mitochondrial dysfunction detectable in ALS, and may be of relevance in development of strategies for the treatment of this disease.

Amyotrophic lateral sclerosis: Prognostic indicators of survival

Amyotrophic lateral sclerosis (ALS) has a fatal outcome in about three years, but survival is known to vary considerably, making it difficult to predict disease duration in individual cases. The aim of this study was to investigate possible early prognostic factors of ALS survival. We included 123 probable or definite cases of ALS, with disease onset between 1989 and 1998, and with a follow‐up of at least one year. Survival functions were obtained using both the Kaplan‐Meier and the actuarial methods. Subgroups, formed on the basis of gender, area of residence, work, and age at and site of onset, were compared using the logrank test and Coxs proportional hazards method (survival functions), and applying the Grizzle, Starmer, Koch (1969), and Koch, Johnson, Tolley (1972) methods (one‐year survival probability trends). The survival curves dipped sharply in the first three years, followed by a flattening trend, with 50% of patients dying within 2.5 years, and 89% over seven years. The clinical form with lower limb onset was associated with longer survival than the upper limb onset and bulbar forms (median survival: 39, 27, and 25 months, respectively). Survival was also affected by age at onset (median survival: 34, 27, and 23 months for onset <60, 60–75, and >75 years, respectively), area of residence (median survival: 24 months in mountainous areas, 32 elsewhere), and type of work (median survival: 25 months in agricultural workers, 33.5 in others). Gender did not influence survival, whereas percutaneous endoscopic gastrostomy placement and invasive ventilation did. The estimation of individual ALS survival is important to allow the patient to plan for his future and to make optimal use of medical and community resources. Although age at and site of onset, area of residence, and agricultural work were found to influence survival, there remains an unexplained heterogeneous progression of the disease, suggesting the influence of other, as yet unknown, prognostic factors. The identification of a definite set of prognostic factors may allow physicians to make more reliable survival predictions at diagnosis.

Do flavan-3-ols from green tea reach the human brain?

Abstract Following acute ingestion of green tea by six human subjects, HPLC-MS 2 analysis revealed that flavan-3-ol methyl, glucuronide and sulfate metabolites appeared in the bloodstream but did not pass through the blood–cerebrospinal fluid barrier. These observations emphasize the discrepancies between in vitro and in vivo evidence on the neuroprotective role of these compounds. If, as has been proposed, green tea exerts neuroprotective effects, this finding indicates that the active components are not flavan-3-ols or their metabolites. Alternatively, a systemic action may be hypothesised whereby dietary flavan-3-ols up-regulate antioxidant defences and/or reduce inflammation, the benefit of which may be effective throughout the body.

Middle cerebral artery thrombosis in course of parvovirus B19 infection in a young adult: A new risk factor for stroke?

Previous infection, both of bacterial and viral origin, is reported to represent an independent risk factor for ischemic stroke in children and young adults. The authors describe the case of an immunocompetent young woman who developed a middle cerebral artery thrombosis and stroke in course of a recurrence of human parvovirus B19 (PVB19) infection. A previously healthy 25-year-old woman developed right ataxic hemiparesis, 5 days after the onset of a flulike syndrome. Magnetic resonance imaging of the brain revealed acute multiple left frontal-parietal ischemic lesions. Conventional and magnetic resonance angiograms revealed a stenosis in the left middle cerebral artery. Nested polymerase chain reaction detected PVB19-specific DNA sequences in the cerebrospinal fluid and blood, and serology showed high titers of high avidity immunoglobulin G against PVB19. After 10 days, the patient’s recovery was nearly complete. One month later, PVB19 disappeared from the serum, whereas it persisted in the peripheral blood mononuclear cells. This case report suggests that PVB19 infection may play a trigger role in the development of ischemic stroke, and that it should be considered in the screening of infectious risk factors for cerebrovascular diseases in young adults.

Total antioxidant capacity of cerebrospinal fluid is decreased in patients with motor neuron disease

Oxidative stress has been associated with motor neuron disease (MND). The human body has several antioxidant defense systems to repair the damage caused by oxidative stress. The activity of these systems is thought to be reduced in neurodegenerative diseases, which may increase the level of oxidative damage and be a contributing factor to motor neuron death. In the present study, we compared the total antioxidant capacity (TAC) of human serum and cerebrospinal fluid (CSF) of MND patients with that of a control group including patients with migraine, tension headache and psychiatric disorders. Within-subject serum and CSF TAC were strongly correlated (r=0.639; p=0.000), and CSF TAC was significantly lower in MND patients as compared to controls after adjustment for known influencing factors (112.7 micromol Fe/L+/-11.7 versus 135.2 micromol Fe/L+/-19.7; p=0.012). No differences in serum or CSF TAC were observed among the clinical forms of MND considered in this work. In conclusion, the CSF TAC was strongly correlated with serum TAC, and a decrease in CSF TAC was demonstrated in MND patients compared to controls that was not independent from serum antioxidants, this translating in a systemic (but prevailing in the CNS) oxidative damage in this pathology.

Monofocal acute large demyelinating lesion mimicking brain glioma

Abstract.We report the case of a 34-year-old woman with clinical, neuroradiological and intraoperative histological findings, suggesting a low-grade astrocytic tumour. The demyelinating nature of the lesion was established through biopsy only after neurosurgery. The lesion size, in fact, greatly exceeded that of the perivenous demyelination seen in typical multiple sclerosis (MS) and tended to present as a spaceoccupying mass. This case underlines the importance of considering demyelinating isolated lesions in the differential diagnosis of a brain mass. Since misdiagnosis can result in unwarranted and aggressive therapy, it is critical for the neurologist to be aware of this serious diagnostic pitfall.

Cerebrospinal fluid amounts of HLA-G in dimeric form are strongly associated to patients with MRI inactive multiple sclerosis

Background: The relevance of human leukocyte antigen (HLA)-G in dimeric form in multiple sclerosis (MS) is still unknown. Objective: To investigate the contribution of cerebrospinal fluid (CSF) HLA-G dimers in MS pathogenesis. Methods: CSF amounts of 78-kDa HLA-G dimers were measured by western blot analysis in 80 MS relapsing–remitting MS (RRMS) patients and in 81 inflammatory and 70 non-inflammatory controls. Results: CSF amounts of 78kDa HLA-G dimers were more frequent in RRMS than in inflammatory (p<0.01) and non-inflammatory controls (p<0.001) and in magnetic resonance imaging (MRI) inactive than in MRI active RRMS (p<0.00001). Conclusion: Our findings suggest that HLA-G dimers may be implicated in termination of inflammatory response occurring in MS.

Biological markers in cerebrospinal fluid for axonal impairment in multiple sclerosis: acetylcholinesterase activity cannot be considered a useful biomarker

An impairment of the cholinergic system activity has been demonstrated in multiple sclerosis (MS). The correlation between the cholinergic system and the cognitive dysfunction in MS has led to studies on the use of acetylcholinesterase inhibitors (AChEI). The acetylcholinesterase (AChE), essential enzyme for the regulation of turnover of acetylcholine, can be considered the most important biochemical indicator of cholinergic signaling in the nervous system. Besides its catalytic properties, AChE has a crucial role in the regulation of the immune function. Based on the role of the AChe in the regulation of cholinergic signaling in the nervous system, the aim of the present study is to evaluate the activity of AChE in different pathological conditions: MS, other inflammatory neurological disorders (OIND) and non-inflammatory neurological disorders (NIND). We measured AChE activity in CSF samples obtained from 34 relapsing–remitting MS patients and, as controls, 40 patients with other inflammatory neurological disorders (OIND) and 40 subjects with other non-inflammatory neurological disorders (NIND). Fluorimetric detection of the AChE in MS patients and in the controls showed no statistically significant differences: 1.507xa0±xa00.403xa0nmol/ml/min in MS patients, 1.484xa0±xa00.496xa0nmol/ml/min in OIND and 1.305xa0±xa00.504xa0nmol/ml/min in NIND. Similar results were obtained in another recent study, using a different method. Further studies must be conducted on a larger number of patients, with different degrees of cognitive impairment. However, AChE measured in CSF can probably not be considered a useful biomarker for the assessment of the functional alterations of cholinergic system in pathological conditions.