Systemic lupus erythematosus (SLE) is an inflammatory ... oxide formation in cerebral systemic lupus ... (stroke, epileptic seizures, transverse myelitis) or gen-.
8. Graham BH, Waymire KG, Cottrell B, et al. A mouse model for mitochondrial myopathy and cardiomyopathy resulting from a deficiency in the heardmuscle isoform of the adenine nucleotide translocator. Nat Genet 1997;16:226-234 9. Beal MF. Mitochondria, free radicals, and neurodegeneration. Curr Opin Neurobiol 1996;6:661-666 10. Smirnow NW,Dunin-Barkowski WI. Mathematische Statistik in der Wissenschaft. Berlin: DVW, 1973:39-40 11. Jenuth JP, Peterson AC, Fu K, et al. Random genetic drift in the female germ line explains the rapid segregation of mammalian mitochondrial DNA. Nat Genet 1996;14:146-151 12. Antozzi C, Franceschetti S, Filippini G, et al. Epilepsia partialis continua associated with NADH-coenzyme Q reductase deficiency. J Neurol Sci 1995;129:152-161 13. Elia M, Musumeci SA, Ferri R. Leigh syndrome and partial deficit of cytochrome c oxidase associated with epilepsia partialis continua. Brain Dev 1996;18:207-21 l 14. Reid FM, Vernham GA, Jacobs HT. A novel mitochondrial point mutation in a maternal pedigree with sensorineural deafness. Hum Mutat 1994;3:243-247 15. Ooiwa Y, Uematsu Y, Terada T, et al. Cerebral blood flow in mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes. Stroke 1993;24:304-309 16. Enriquez JA, Chomyn A, Attardi G. mtDNA mutation in MERFF syndrome causes defective aminoacylation of tRNALYs and premature translation termination. Nat Genet 1995;lO:
47-55 17. Degoul F, Franqois D, Diry M, et al. A near homoplasmic T8993G mtDNA mutation in a patient with atypic Leigh syndrome not present in the mother’s tissues. J Inherit Metab Dis 1997;20:49 -53 18. Shoubridge FA. Mitochondria1 DNA diseases: histological and cellular studies. J Bioenerg Biomembr 1994;26:301-310 19. Yoneda M, Chomyn A, Martinuzzi A, et al. Marked replicative advantage of human mtDNA carrying a point mutation that causes the MELAS encephalomyopathy. Proc Natl Acad Sci USA 1992;89:11164-11168 20. Weber K, Wilson JN, Taylor L, et al. A new mtDNA mutation showing accumulation with time and restriction to skeletal muscle. Am J Hum Genet 1997;60:373-380 21. Lissens W, Sermon K. pre-implantation diagnosis: current status and new developments. Hum Reprod 1997;12:1756-1761
Central Nervous System Nitric Oxide Formation in Cerebral Systemic Lupus Erythematosus L. Brundin, MD,* E. Svenungsson, MD,? E. Morcos, MD,* M. Anderson, MD,*$ T. Olsson, MD,$ I. Lundberg, MD,? and N. P. Wiklund, MD*
Systemic lupus erythematosus (SLE)is an inflammatory disease in which up to two thirds of the patients present neurological symptoms. The diagnosis of the disease is based on clinical findings and the presence of autoantibodies, and the pathogenesis is unclear. The purpose of this study was to determine if the pathogenesis was partly mediated via nitric oxide (NO) formation. Cerebrospinal fluid (CSF) samples from 15 patients with cerebral SLE were analyzed for the NO metabolites nitrite and nitrate using capillary electrophoresis. The severity of neurological symptoms was scored by dividing the patients into two groups with either mild or moderatehevere CNS involvement. All patients with cerebral SLE showed increased levels of NO metabolites. In CSF, there was a relationship between signs of NO production and clinical results showing that increased levels of nitrite and nitrate were associated with more severe neurological symptoms. These findings may shed new light on the pathogenesis of cerebral SLE, and analysis of nitrate and nitrate may prove to be of value in monitoring the activity of the disease. Brundin L, Svenungsson E, Morcos E, Anderson M, Olsson T, Lundberg I, Wiklund NP. Central nervous system nitric oxide formation in cerebral systemic lupus erythernatosus. Ann Neurol 1998;44:704-706
Systemic lupus erythematosus (SLE) is an inflammatory disease mainly affecting women of fertile age. The diagnosis is based on clinical findings of typical multiorgan involvement in combination with laboratory tests showing increased production of defined autoantibodies. Up to two thirds of these patients experience
From the *Department of Clinical Neuroscience, Divisions of TRheumatology and $Urology, and SNeuroimmunology Unit of the Department of Medicine, Karolinska Institute, Karolinska Hospital, Stockholm, Sweden. Received Dec 2, 1997, and in revised form May 13, 1998. Accepted for publication May 13, 1998. Address correspondence to Dr Brundin, Department of Clinical Neuroscience, Division of Neurology, Karolinska Institute, Karolinska Hospital, S 171 77 Stockholm, Sweden.
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Copyright 0 1998 by the American Neurological Association
neuropsychiatric symptoms,’ which may be focal (stroke, epileptic seizures, transverse myelitis) or general (psychosis, depression, cognitive impairment, dementia) in origin. These symptoms may respond to immunosuppressive therapy but are often misdiagnosed as they may be clinically indistinguishable from other neurological/psychiatric conditions. To a large extent, the pathogenesis is still unclear. Nitric oxide (NO) is synthesized from L-arginine by the enzyme N O synthase; NO is an important mediator of vascular tone and pulmonary perfusion and acts as a neurotransmitter in both the central (CNS) and peripheral nervous systems.’ In the CNS, astrocytes and microglia contain iNOS, which can be induced and cause neuronal cell death.3 Increased expression of iNOS in the CNS system has been clearly demonstrated in patients with bacterial meningitis,* in experimental autoimmune en~ephalomyelitis,~~‘ and in some studies of patients with multiple ~ c l e r o s i s .N~O ~ ~is rapidly broken down to the more stable oxidation products nitrite and nitrate in biological tissues.’ Thus, assays of nitrite and nitrate are widely used as indicators of N O formation.’ The purpose of this study was to determine if patients with cerebral SLE showed increased N O production in the CNS and if the severity of the neuropsychiatric symptoms was reflected in measurements of N O metabolite levels in cerebrospinal fluid (CSF). Patients and Methods
Patients All patients entering the study fulfilled the American College of Rheumatology criteria for SLE.” Patients with diagnosed SLE presenting with neurological symptoms were examined by a neurologist and a rheumatologist. The symptoms were scored as follows: mild SLE when there was cognitive impairment and moodlanxiety syndromes but no focal signs, and moderatelsevere SLE when there was paresis, epileptic seizures, psychosis, severe neuralgia, or dementia. Patients presenting with two or more of these symptoms were rated as severely affected. Plasma samples and samples of CSF were obtained (the latter by routine lumbar puncture) with patient consent. The protocol was authorized by the Ethics Committee of the Karolinska Hospital. The clinicians rating the symptoms had no access to the nitrite/nitrate determinations. We applied no food or drink restrictions to the patients or controls entering the study.
Sample Analysis Sample analysis for NO metabolites was performed using a capillary electrophoresis technique.’ Vials and equipment were rinsed in deionized distilled water (Elgastat prima 1-3, Elga, Buckinghamshire, UK). The samples were diluted l : l O , ultrafiltered at 5000 g through Ultrafree-MC filters (Millipore; Bedford, MA), and analyzed on a Hewlett Packard 3D capillary electrophoresis system (Hewlett Packard, Waldbronn, Germany). The electrolyte consisted of 25 mM of sodium sulphate containing 5% NICE-Pak OFM Anion-BT (osmotic flow modifier) in deionized distilled water. Samples were injected by electromigration for 20 seconds at -6 kV and analyzed at a negative potential of 300 Vcm-’ . Data were acquired at a response time of 0. I second at 214 nm onto a Hewlett Packard 3D CE Chem Station data system. The samples were coded to the laboratory staff.
Statistics The correlation between symptom and nitratelnitrite levels was evaluated by ANOVA.
Results When compared with age- and gender-matched controls, CSF levels of nitrite and nitrate in patients with low/moderate symptoms (SLE+) were significantly increased. The total concentrations of nitrite plus nitrate were 6.6 t 0.7 mM for controls and 10.4 L 1.2 mM for the mildly affected patients. In severely affected patients (SLE+ +), the increase in nitrite and nitrate levels was even more pronounced, giving a mean concentration of 19.7 -+ 2 mM. Interestingly, the plasma nitrite and nitrate levels correlated neither to CSF levels nor to severity of the neurological symptoms (Fig). The maximum concentration 22 pM was obtained from a patient previously diagnosed with cerebral SLE, who became acutely psychotic. After cortisone treatment, she recovered from the attack and nitrate/nitrite
Fig. Cerebrospinalj u i d (CSfJ concentration of nitric oxide (NO) oxidation products in the CSF of normal controls, patients with mild neurological symptoms (SLE+), and patients with moderateheveve neurological impairment (SLES +) (p < 0.0001).
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Controls Samples of CSF from age- and gender-matched headache patients were used as controls. The CSF of control patients was screened for protein, glucose, and cell content and underwent spectrophotometry. Guidelines for control patients were that they should be healthy in other respects, not present with neurological signs, and be relieved of their headache within 5 days.
Normal n=6
SLE t n=10
SLE ++ n=5
Brief Communication: Brundin et al: CNS N O Formation in Cerebral SLE
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concentrations were down at 7.8 FM in the chronic state of the disease. Discussion In a recent report, SLE patients with pulmonary symptoms had increased levels of N O in exhaled air." NO formation may constitute a common inflammatory pathway, because increased levels of N O metabolites appear in CSF, indicating increased NO formation in the CNS. Patients with CNS SLE may respond to cortisone treatment, which is in agreement with the finding that glucocorticoids inhibit the expression of iNOS.12 Furthermore, these results suggest that CNS involvement in SLE is proportional to the levels of NO metabolites measured in CSF. The means of objectively monitoring the CNS involvement in this disease are scarce, because there are no tests previously described that reveal acute activity or remission. Monitoring CSF levels of NO oxidation products may distinguish between a psychological reaction and a relapse of cerebral SLE. In addition, it should be of interest to study whether NO, per se, is instrumental for the neuropsychiatric disturbances seen during SLE or whether it serves as a marker for other inflammatory events systemically or intrathecally involved in CNS damage. NO formation in the CNS may shed new light on the pathogenesis of cerebral SLE. ~
~~~
This work was supported by the Swedish Medical Council and the Konung Gustav V Memorial Foundation.
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