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0286 HLA typing in Saudi patients with myasthenia gravis
S172
Poster Abstracts
Monday, November 7, 2005
Results and conclusion: Seven patients from 5 unrelated families have one o f the primary mutations. This indexed family has a T14484C primary mutation, and 4 secondary mutations (T4216C, G13708A, G15812A, G15257A), which belong to the European haplogroup J. The new sequence variant of A9016G in the ATPase 6 gene changed highly conserved amino acid of isoleucine to valine, has not been found in the rest of 13 LHON patients and controls. This novel sequence variant may contribute to the 100% penetration of LHON disorder in men of this family. 0282 ATP synthesis: tile trigger between Apoptosis and Necrosis in paiients with Mitoehondtial disorders Shepherd, RK ~, Sue, CM a. 1Department of Neurogeneties, Kolling Institute of Medical Research, Royal North Shore Ho@ital and the University of Sydney, Sydney, Australia Background: Mitochondrial diseases can be associated with nmtations in both nuclear D N A (nDNA) and mitochondrial D N A (mtDNA). Mitochondrial disease is typically characterised by impaired respiratory chain function and reduced ATP synthesis. Respiratory chain dysfunction can lead to increased reactive oxygen species (ROS) production, which may lead to cell death via apoptosis or necrosis. The aim of tiffs study was to determine whether disturbances in ATP synthesis results in the cell becoming more susceptible to apoptotic or necrotic cell death following exposure to oxidative stress. Methods: ATP synthesis was measured in fibroblast cell lines from patients with m t D N A mutations (in - 8), n D N A mutations (in - 2) and control subjects (in - 7). Cell lines were also exposed to antimycin A for 2 hours. Cell death was characterised by acridine orange staining and fluorescent microscopy. Results: Patients with nDNA-encoded disorders had greater reductions in ATP synthesis compared to patients with mtDNA-encoded disorders. Nuclear condensation, indicative of apoptosis was observed in 29-51% (mean -- 42%) of cells in cultures derived from patients with m t D N A mutations, 21-26% (mean 24%) of cells in cultures derived from patients with n D N A defects and 26-49% (mean 37%) in control fibroblasts. Nuclear swelling indicative of necrosis was also observed in the cells derived from patients with n D N A defects. Conclusion: Fibroblasts with m t D N A mutations and mild reductions in ATP synthesis undergo apoptotic cell death pathways following exposure to oxidative stress. However, necrosis occurs in fibroblasts with n D N A defects and markedly reduced ATP synthesis. 0283 Apoptosis is Evident in Muscle Biopsies of Patients with Mitoehomirial Myopathy Tate, FY l, Brewer, j 2 Sue, CM i. 1Department of Neurology, Royal
North Shore Hospital and University of Sydney, Australia; 2Department of Anatomical Pathology, PALMS, Royal North Shore Hospital, Sydney, Australia Background: Mitochondrial myopathy (MM) is a muscle disease diagnosed by morphological changes in nluscle biopsies. The mechanisnl of nmscle degeneration is poorly understood, but apoptosis has been reported to be involved. Objective: To establish the presence of apoptotic changes in a large nunlber of patients with M M and to characterise the mechanism initiating cell death in affected muscle fibres. Method: hmnunotffstochemical studies were performed on muscle biopsies from 20 M M patients and 3 unaffected individuals. We used ten specific antibodies: F A D D (death receptor activation), B A x , and Phospho-Bcl-2, Bad, AIF, cytochrome c (mitochondrial involvement), active caspase-3, active caspase-8, caspase-12, and cleaved-PARP (nuclear involvement). Results: Cytoplasnffc expression of BAX, phospho-Bcl-2, BAD, cytochrome c, active caspase-3, cleaved-PARP, and AIF, indicative
of loss mitochondrial membrane potential and nuclear breakdown was observed. Caspase-12 positive fibres were observed in some patients (35%). All increase in F A D D expression was also observed in 50% of patients. Conclusion: Apoptosis is evident in nmscle biopsies o f patients with MM. Increased expression o f AIF and cleaved-PARP indicated that apoptosis was advanced. Upregulation of BAN, phospho-Bcl-2, and Bad indicated the loss of rnitochondrial membrane potential. High expression of caspase-12, implicated increased endoplasmic reticuhim (ER) stress in these patients. The mechanisms of cell death in M M patients may involve both caspase-dependent and caspase-independent pathways initiated by intrinsic, responses (such as ER stress, A I F release and Bcl-2 cleavage). Activation of both these pathways are likely to contribute to muscle degeneration in affected patients. 0285 Neuropsycllonletrie protiling in a case of Maternally inllerited diabetes and dealiless Vaithianathar L l, Vesey pa, Goddard A ~, Robson D.K a, Suri M 2, Bajaj
N a. 1 Queens Medical Centre, Nottingham, United Kingdom; 2City Hospital, Nottingham, United Kingdom Background: Neuropsychiatric symptoms have been reported in the mitochondrial disorder: maternally inherited diabetes and deafness (MIDD) but are not well characterised. Severe dementia has not been described. Case: We performed a cognitive evaluation and neuroimaging in a fourty-nine year old lady with M I D D (confimted by genetic testing and clinical criteria) who presented with an aggressive, recent onset denlentia. Decline in memory, language problems and poor concentration were reported over an eighteen-month period. The past medical history included recurrent miscarriages, bilateral sensorineural deafness, cardiac disease, pigmentary retinopathy, diabetes, hypothyroidism, migraine and neuromuscular weakness. There was a maternal fanffly history o f diabetes, deafness and cardiac disease. Results: Genetic testing demonstrated an A3243G point mutation in mitochondrial DNA. Her muscle biopsy was abnormal. Neuropsychometry showed a subnormal IQ. Language ability was relatively intact. Attention, working memory and speed of processing were poor. There was visual-perceptual and frontal executive dysfunction. Remote/semantic menlory was impaired. She had poor immediate and delayed recall o f new verbal information and poor recognition. Neuroimaging showed generalised atrophy, more marked in the right temporal lobe and normal spectroscopy. Discussion: Neuropsychological impaimlent Call be severe and global in MIDD, with a cortical rather than subcortical pattern of dementia. 0286 H I A typing in Saudi patients with illyasttletlia gravis AI Jumah, M l, Hajeer, A ~, AI Suwaidan, F a, Bohlegh, S2, AI Tahan, A ~, Cktpler, E ~. 1King Abdzdaziz Medical City, Riyadh,
Saudi Arabia; 2King Faisal Specialist Hospital & Research Center, Riyadh, Saudi Arabia; 3King KJlaled Ho@ital, King Saudi University Myasthelffa Gravis (MG) is all autoimmune disorder involving N M J receptors. Moderate association of M G with the human leukocyte antigen (HLA) system that are coded for by MCH genes has been described. M G associated with HLA system varies in different ethnic groups. Ill Caucasians, M G associated with tile HLA antigens B8, DR3 and DQW2, particularly in young females with thynffc hyperplasia. However, H L A association is different in Japanese and French patients. Pilot study in Saudi M G patients suggested association with HLA DQ5 and B18. Objectives: To study the association of M G with HLA antigen in Saudis. Methods: Ninety three (193) patients fi'om different fanfflies with confirmed diagnosis of M G and 100 nomlal controls were involved in
Poster Abstracts
Monday, November 7, 2005
Results and conclusion: Seven patients from 5 unrelated families have one o f the primary mutations. This indexed family has a T14484C primary mutation, and 4 secondary mutations (T4216C, G13708A, G15812A, G15257A), which belong to the European haplogroup J. The new sequence variant of A9016G in the ATPase 6 gene changed highly conserved amino acid of isoleucine to valine, has not been found in the rest of 13 LHON patients and controls. This novel sequence variant may contribute to the 100% penetration of LHON disorder in men of this family. 0282 ATP synthesis: tile trigger between Apoptosis and Necrosis in paiients with Mitoehondtial disorders Shepherd, RK ~, Sue, CM a. 1Department of Neurogeneties, Kolling Institute of Medical Research, Royal North Shore Ho@ital and the University of Sydney, Sydney, Australia Background: Mitochondrial diseases can be associated with nmtations in both nuclear D N A (nDNA) and mitochondrial D N A (mtDNA). Mitochondrial disease is typically characterised by impaired respiratory chain function and reduced ATP synthesis. Respiratory chain dysfunction can lead to increased reactive oxygen species (ROS) production, which may lead to cell death via apoptosis or necrosis. The aim of tiffs study was to determine whether disturbances in ATP synthesis results in the cell becoming more susceptible to apoptotic or necrotic cell death following exposure to oxidative stress. Methods: ATP synthesis was measured in fibroblast cell lines from patients with m t D N A mutations (in - 8), n D N A mutations (in - 2) and control subjects (in - 7). Cell lines were also exposed to antimycin A for 2 hours. Cell death was characterised by acridine orange staining and fluorescent microscopy. Results: Patients with nDNA-encoded disorders had greater reductions in ATP synthesis compared to patients with mtDNA-encoded disorders. Nuclear condensation, indicative of apoptosis was observed in 29-51% (mean -- 42%) of cells in cultures derived from patients with m t D N A mutations, 21-26% (mean 24%) of cells in cultures derived from patients with n D N A defects and 26-49% (mean 37%) in control fibroblasts. Nuclear swelling indicative of necrosis was also observed in the cells derived from patients with n D N A defects. Conclusion: Fibroblasts with m t D N A mutations and mild reductions in ATP synthesis undergo apoptotic cell death pathways following exposure to oxidative stress. However, necrosis occurs in fibroblasts with n D N A defects and markedly reduced ATP synthesis. 0283 Apoptosis is Evident in Muscle Biopsies of Patients with Mitoehomirial Myopathy Tate, FY l, Brewer, j 2 Sue, CM i. 1Department of Neurology, Royal
North Shore Hospital and University of Sydney, Australia; 2Department of Anatomical Pathology, PALMS, Royal North Shore Hospital, Sydney, Australia Background: Mitochondrial myopathy (MM) is a muscle disease diagnosed by morphological changes in nluscle biopsies. The mechanisnl of nmscle degeneration is poorly understood, but apoptosis has been reported to be involved. Objective: To establish the presence of apoptotic changes in a large nunlber of patients with M M and to characterise the mechanism initiating cell death in affected muscle fibres. Method: hmnunotffstochemical studies were performed on muscle biopsies from 20 M M patients and 3 unaffected individuals. We used ten specific antibodies: F A D D (death receptor activation), B A x , and Phospho-Bcl-2, Bad, AIF, cytochrome c (mitochondrial involvement), active caspase-3, active caspase-8, caspase-12, and cleaved-PARP (nuclear involvement). Results: Cytoplasnffc expression of BAX, phospho-Bcl-2, BAD, cytochrome c, active caspase-3, cleaved-PARP, and AIF, indicative
of loss mitochondrial membrane potential and nuclear breakdown was observed. Caspase-12 positive fibres were observed in some patients (35%). All increase in F A D D expression was also observed in 50% of patients. Conclusion: Apoptosis is evident in nmscle biopsies o f patients with MM. Increased expression o f AIF and cleaved-PARP indicated that apoptosis was advanced. Upregulation of BAN, phospho-Bcl-2, and Bad indicated the loss of rnitochondrial membrane potential. High expression of caspase-12, implicated increased endoplasmic reticuhim (ER) stress in these patients. The mechanisms of cell death in M M patients may involve both caspase-dependent and caspase-independent pathways initiated by intrinsic, responses (such as ER stress, A I F release and Bcl-2 cleavage). Activation of both these pathways are likely to contribute to muscle degeneration in affected patients. 0285 Neuropsycllonletrie protiling in a case of Maternally inllerited diabetes and dealiless Vaithianathar L l, Vesey pa, Goddard A ~, Robson D.K a, Suri M 2, Bajaj
N a. 1 Queens Medical Centre, Nottingham, United Kingdom; 2City Hospital, Nottingham, United Kingdom Background: Neuropsychiatric symptoms have been reported in the mitochondrial disorder: maternally inherited diabetes and deafness (MIDD) but are not well characterised. Severe dementia has not been described. Case: We performed a cognitive evaluation and neuroimaging in a fourty-nine year old lady with M I D D (confimted by genetic testing and clinical criteria) who presented with an aggressive, recent onset denlentia. Decline in memory, language problems and poor concentration were reported over an eighteen-month period. The past medical history included recurrent miscarriages, bilateral sensorineural deafness, cardiac disease, pigmentary retinopathy, diabetes, hypothyroidism, migraine and neuromuscular weakness. There was a maternal fanffly history o f diabetes, deafness and cardiac disease. Results: Genetic testing demonstrated an A3243G point mutation in mitochondrial DNA. Her muscle biopsy was abnormal. Neuropsychometry showed a subnormal IQ. Language ability was relatively intact. Attention, working memory and speed of processing were poor. There was visual-perceptual and frontal executive dysfunction. Remote/semantic menlory was impaired. She had poor immediate and delayed recall o f new verbal information and poor recognition. Neuroimaging showed generalised atrophy, more marked in the right temporal lobe and normal spectroscopy. Discussion: Neuropsychological impaimlent Call be severe and global in MIDD, with a cortical rather than subcortical pattern of dementia. 0286 H I A typing in Saudi patients with illyasttletlia gravis AI Jumah, M l, Hajeer, A ~, AI Suwaidan, F a, Bohlegh, S2, AI Tahan, A ~, Cktpler, E ~. 1King Abdzdaziz Medical City, Riyadh,
Saudi Arabia; 2King Faisal Specialist Hospital & Research Center, Riyadh, Saudi Arabia; 3King KJlaled Ho@ital, King Saudi University Myasthelffa Gravis (MG) is all autoimmune disorder involving N M J receptors. Moderate association of M G with the human leukocyte antigen (HLA) system that are coded for by MCH genes has been described. M G associated with HLA system varies in different ethnic groups. Ill Caucasians, M G associated with tile HLA antigens B8, DR3 and DQW2, particularly in young females with thynffc hyperplasia. However, H L A association is different in Japanese and French patients. Pilot study in Saudi M G patients suggested association with HLA DQ5 and B18. Objectives: To study the association of M G with HLA antigen in Saudis. Methods: Ninety three (193) patients fi'om different fanfflies with confirmed diagnosis of M G and 100 nomlal controls were involved in