Johan Jacobsson

Novel antibodies reveal inclusions containing non-native SOD1 in sporadic ALS patients

Mutations in CuZn-superoxide dismutase (SOD1) cause amyotrophic lateral sclerosis (ALS) and are found in 6% of ALS patients. Non-native and aggregation-prone forms of mutant SOD1s are thought to trigger the disease. Two sets of novel antibodies, raised in rabbits and chicken, against peptides spaced along the human SOD1 sequence, were by enzyme-linked immunosorbent assay and an immunocapture method shown to be specific for denatured SOD1. These were used to examine SOD1 in spinal cords of ALS patients lacking mutations in the enzyme. Small granular SOD1-immunoreactive inclusions were found in spinal motoneurons of all 37 sporadic and familial ALS patients studied, but only sparsely in 3 of 28 neurodegenerative and 2 of 19 non-neurological control patients. The granular inclusions were by confocal microscopy found to partly colocalize with markers for lysosomes but not with inclusions containing TAR DNA binding protein-43, ubiquitin or markers for endoplasmic reticulum, autophagosomes or mitochondria. Granular inclusions were also found in carriers of SOD1 mutations and in spinobulbar muscular atrophy (SBMA) patients and they were the major type of inclusion detected in ALS patients homozygous for the wild type-like D90A mutation. The findings suggest that SOD1 may be involved in ALS pathogenesis in patients lacking mutations in the enzyme.

Cerebrospinal fluid neurofilament light levels in amyotrophic lateral sclerosis : impact of SOD1 genotype

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative syndrome with familial and sporadic forms. Most ALS‐associated mutations are found in the superoxide dismutase 1 (SOD1) gene. We conducted a study including 60 sporadic and 19 familial ALS patients, 206 reference patients with other neurological disorders and 40 age‐ and sex‐matched healthy controls to test the hypothesis that cerebrospinal fluid (CSF) levels of neurofilament light (NF‐L) protein, a marker of axonal degeneration, might provide diagnostic and prognostic information on the disease. All ALS patients were screened for SOD1 mutations. Ten of the familial and five of the sporadic cases carried SOD1 mutations. NF‐L concentration [median (range)] was strongly elevated in ALS [2110 (255–10 800) ng/l] compared with reference patients and healthy controls [277 (<125–15 506) and 175 (<125–710) ng/l, respectively, P < 0.001] and correlated inversely with disease duration (Spearman R = −0.518, P = 0.001). NF‐L levels were lower in SOD1 mutation‐associated ALS compared with SOD1 wild‐type (wt) ALS (P = 0.03). In conclusion, CSF NF‐L levels may provide both diagnostic and prognostic information, particularly in SOD1 wt ALS.

Reference values for CSF outflow resistance and intracranial pressure in healthy elderly

Objective: The intracranial pressure (ICP) and CSF outflow resistance (Rout) are essential to describe the dynamics of the CSF system. Rout affects ICP, pulse amplitudes, CSF absorption, and the compliance of the system. The objective of this study was to determine the reference values in healthy elderly subjects. Methods: Elderly people (60–82 years), who considered themselves healthy, were recruited through an advertisement in the local newspaper. All were evaluated with a 3-T MRI. Subjects were eligible if they did not have any psychiatric or neurologic disorder or signs of advanced atherosclerotic disease. CSF resting pressure (ICP) and Rout were determined by a constant pressure infusion method with the patient in the supine position. The study population consisted of 40 subjects (mean age 70 years; 23 women). Results: The median ICP was 11.6 mm Hg (15.8 cmH2O) and the reference interval was ICP 7.8–14.3 mm Hg (10.6–19.4 cmH2O) (defined as 5th to 95th percentiles). The median Rout was 8.6 mm Hg/mL/min. The variation in Rout was large and not normally distributed. The 90th percentile of Rout was 17.4 mm Hg/mL/min. Conclusions: This study reports reference values for ICP and Rout and should be used for comparison when investigating disorders with suspected CSF dynamic disturbances in the elderly. ICP was in the same range as that reported in the young and middle-aged. The upper limit of Rout was higher than previously believed to be the upper limit of normal for this age group.

Association of APOE with age at onset of sporadic amyotrophic lateral sclerosis.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative syndrome with familial and sporadic forms. We conducted a study including 60 sporadic and 19 familial ALS patients, 206 reference patients with other neurological disorders and 1265 neurologically healthy controls to assess the Alzheimer-associated apolipoprotein E (APOE) epsilon4 gene variant as a possible risk factor for ALS. While no major influence of APOE epsilon4 on disease risk was detected, a gene dose-dependent effect with lower age at onset of sporadic ALS in epsilon4 carriers was found (p=0.027). These data support APOE epsilon4 as a subordinate contributing factor in ALS.

CuZn-superoxide dismutase in D90A heterozygotes from recessive and dominant ALS pedigrees

Mutations in CuZn-superoxide dismutase (CuZn-SOD) have been linked to ALS. In most cases ALS is inherited as a dominant trait and there is marked reduction in CuZn-SOD activity in samples from the patients. The D90A mutation, however, mostly causes ALS as a recessive trait and shows near normal CuZn-SOD activity. A few familial and sporadic ALS cases heterozygous for the D90A mutation have also been found. Haplotype analysis of both types of D90A families has suggested that all recessive cases share a common founder and may carry a protective factor located close to the D90A mutant CuZn-SOD locus. To search for effects of a putative protective factor we analysed erythrocytes from D90A heterozygous individuals for SOD activity by a direct assay, subunit composition by immunoblotting, and zymogram pattern formed by isoelectric focusing and SOD staining. Included were heterozygotes from 17 recessive families, and from 2 dominant families and 4 apparently sporadic cases. The CuZn-SOD activity in the recessive and dominant groups was found to be equal, and 95% of controls. The ratio between mutant and wildtype subunits was likewise equal and 0.8:1 in both groups. The zymograms revealed multiple bands representing homo- and heterodimers. There were, however, no differences between the groups in patterns or in ratios between the molecular forms. In conclusion we find no evidence from analyses in erythrocytes that the putative protective factor in recessive families acts by simply downregulating the synthesis or altering the molecular structure or turnover of the mutant enzyme.

Cerebrospinal fluid and blood flow patterns in idiopathic normal pressure hydrocephalus

Increased aqueduct cerebrospinal fluid (CSF) flow pulsatility and, recently, a reversed CSF flow in the aqueduct have been suggested as hallmarks of idiopathic normal pressure hydrocephalus (INPH). However, these findings have not been adequately confirmed. Our objective was to investigate the flow of blood and CSF in INPH, as compared to healthy elderly, in order to clarify which flow parameters are related to the INPH pathophysiology.

A novel dynamin-2 gene mutation associated with a late-onset centronuclear myopathy with necklace fibres

Nuclear centralisation and internalisation, sarcoplasmic radiating strands and type 1 muscle fibre predominance and hypotrophy characterise dynamin-2 (DNM2) associated centronuclear myopathy, whereas necklace fibres are typically seen in late onset myotubularin-1 (MTM1)-related myopathy. We report a woman with unilateral symptoms probably related to brachial plexus neuritis. Electromyography revealed localised neuropathic and generalised myopathic abnormalities. The typical features of DNM2 centronuclear myopathy with additional necklace fibres were found in the muscle biopsy. Sequencing of the DNM2 and MTM1 genes revealed a novel heterozygous missense mutation in exon 18 of the DNM2, leading to replacement of highly conserved proline at position 647 by arginine. The muscle symptoms have not progressed during the 3-year follow-up. However, the patient has developed bilateral subtle lens opacities. Our findings support the concept that necklace fibres may occasionally be found in DNM2-related myopathy, possibly indicating a common pathogenic mechanism in DNM2 and MTM1 associated centronuclear myopathy.

C.P.9 A novel dynamin-2 gene mutation associated with a late-onset centronuclear myopathy with unusual clinical presentation and necklace fibres

A novel dynamin-2 gene mutation associated with a late-onset centronuclear myopathy with unusual clinical presentation and necklace fibres

P4-127: CSF neurofilament light as a diagnostic and prognostic biomarker for amyotrophic lateral sclerosis

levels of GDNF in the brains of scrapie-infected mice on the days of post-inoculation (dpi) of 100 and 160. In addition, we found that more intensive immunoreactivities of GDNF in the brains of scrapie-infected mice, specifically in the hippocampal astrocytes, than in those of control mice. Conclusions: This study suggest that up regulation of GDNF expression in scrapie-infected brain may play a function to protect the neuronal cell loss and astrophy in neurodegenerative disorders, which is one of the important role in the pathogenic mechanisms of prion diseases. Acknowledgment: This study was supported by a grant of the Korea Health 21 R&D Project, Ministry of Health & Welfare, Republic of Korea.