Late-onset myasthenia gravis. Follow-up of 113 patients diagnosed after age 60.
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Biomedical subjects
Publications and source records attributed to N Sommer.
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CD95-mediated apoptosis is a potent endogenous pathway of T cell elimination that has been suggested to be altered in multiple sclerosis (MS). MS is associated with the HLA-DR2, Dw2, DQ6 HLA class II haplotype. We have previously reported that T cell lines from HLA-DR2-positive individuals show enhanced production of tumor necrosis factor (TNF), a cytokine homologous to CD95 ligand, in response to specific antigen. Here we have studied CD95 expression and susceptibility to CD95-mediated apoptosis in peripheral blood mononuclear cells (PBMC) and activated T cells of 20 healthy individuals and 20 MS patients, half of whom were HLA-DR2-positive. MS patients did not differ from healthy individuals in either parameter. There was also no difference in CD95 expression or CD95-mediated apoptosis when MS patients and healthy individuals were grouped and compared according to HLA-DR status. These data reveal no differential regulation of PBMC/T cell apoptosis induced by CD95 receptor ligation in MS and show no impact of HLA-DR2 status on PBMC/T cell susceptibility to the same apoptotic stimulus. However, to assess the contribution of T cell apoptosis to the pathogenesis of MS further studies on other details of the complex system leading to T cell apoptosis are required.
Extensive research in the field of multiple sclerosis (MS) has lead to a preliminary pathogenetic concept without solving the etiopathogenesis. According to animal experiments and human in vitro studies MS is a T cell-mediated autoimmune disease. Experimental therapeutical strategies are aiming at the inhibition of T cell activation, transmigration through the blood brain barrier and local inflammation and demyelination. Several substances are already being tested in clinical studies with magnetic resonance imaging as a tool to quantify inflammatory lesions and to shorten the study course. This review will give a summary about actual experimental therapies resulting from the current pathogenetic concept.
Autoaggressive T-cells specific for myelin proteins like proteolipid protein (PLP) and myelin basic protein (MBP) are thought to play a major role in the pathogenesis of demyelinating diseases of the central nervous system (CNS). 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNPase) is the third most abundant myelin protein in the CNS. Due to lack of supply with enough CNPase of sufficient purity its immunologic properties have not been studied yet. We subcloned a human CNPase cDNA and expressed human recombinant CNPase (rh-CNPase) in E. coli. Purification of the protein was achieved by Ni(2+)-chelating chromatography. Furthermore we describe for the first time several rh-CNPase specific T-cell lines from a multiple sclerosis patient and a healthy control.
It was recently demonstrated that selective phosphodiesterase type 4 (PDE4) inhibition suppresses the clinical manifestations of acute experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS), and inhibits the production of tumor necrosis factor-alpha (TNF-alpha), a pathogenetically central cytokine. Since the most common presentation of MS in humans is a relapsing-remitting course, we investigated the therapeutic potential of PDE4 inhibition in the relapsing-remitting EAE model of the SJL mouse. Administration of rolipram, the prototypic PDE4 inhibitor, reduced the clinical signs of EAE during both the initial episode of disease and subsequent relapses. In parallel, there was marked reduction of demyelination and also less inflammation throughout the central nervous system (CNS) of rolipram-treated animals. Gene expression of proinflammatory cytokines in the CNS was reduced in most of the rolipram-treated animals. Additional experiments demonstrated that PDE4 inhibition acted principally by inhibiting the secretion of Th1 cytokines, however, the encephalitogenic potential of myelin basic protein-specific T cells was not impaired. Our findings suggest that PDE4 inhibitors are a promising cytokine-directed therapy in chronic demyelinating disease.
OBJECTIVE: Ocular myasthenia gravis is a subtype of myasthenia gravis that causes relatively mild disability, but may convert into severe generalised muscle weakness. A universal management plan for ocular myasthenia gravis has not been established. This study was performed to determine the outcome of ocular myasthenia gravis with the currently available therapeutic options. METHODS: Retrospective analysis of 78 patients with ocular myasthenia gravis with a mean disease duration of 8.3 (range 0.5-58.3) years. RESULTS: In 54 patients (69%) symptoms and signs remained confined to the extraocular muscles during the observation period. The remaining 24 patients (31%) developed symptoms of generalised myasthenia gravis; 50% of them within two years, 75% within four years after onset. A somewhat reduced risk of generalisation was found in those with mild symptoms, normal repetitive nerve stimulation test, and low or absent antiacetylcholine receptor (AChR) antibodies at the time of diagnosis. Patients receiving immunosuppressive treatment (corticosteroids and/or azathioprine) rarely developed generalised myasthenia gravis (six of 50, 12%). Those without such treatment, usually due to uncertain diagnosis and late referral, converted into generalised myasthenia gravis significantly more often (18 of 28, 64%). CONCLUSIONS: The prognosis of ocular myasthenia gravis is good. A conventional scheme with short-term corticosteroids and long-term azathioprine seems adequate to achieve remission in most patients. The proportion of patients developing generalised myasthenia gravis was smaller in this population compared with previously published groups (usually 50%-70%). Early immunosuppressive treatment is at least partially responsible for this finding. Thymectomy (performed here in 12 patients with an abnormal chest CT) also correlated with a good outcome, but had no apparent advantage over medical treatment alone.
Epidemiological studies have provided evidence for a genetic contribution to the susceptibility of multiple sclerosis (MS). One in six patients has at least one affected family member. The concordance rate is approximately 25% in monozygotic twins, and 3% in siblings, however the prevalence in adopted siblings is similar to the general population (0.1%) MS is thought to be a T cell-mediated autoimmune disease and therefore genes controlling the immune response have been studied intensively as potential susceptibility factors. The best documented association was found for genes of the human-leukocyte antigen complex. Other possible susceptibility genes may reside in the regions of the T cell receptors and the tumour necrosis factors. So far it is clear, that MS is a multifactorial disease in which several genes must be involved. Population genetics and molecular biology will help to characterise further these susceptibility factors.
In multiple sclerosis (MS) and its animal model experimental autoimmune encephalomyelitis (EAE) the cytokines tumour necrosis factor-alpha (TNF), lymphotoxin-alpha (LT), and interferon-gamma (IFN-gamma) are of central pathogenetic importance. A therapy capable of stopping neurological deterioration in MS patients is not yet available. Here, we report that rolipram, a selective type IV phosphodiesterase inhibitor, stereospecifically suppresses the production of TNF/LT and less strongly also IFN-gamma in human and rat auto-reactive T cells. Moreover, we show that rolipram is an effective treatment for EAE. Rolipram has extensively been studied in humans for the treatment of depression, but has not yet been marketed. The data presented here identify rolipram as potential therapy for multiple sclerosis and provoke the immediate initiation of clinical trials.
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Myasthenia gravis (MG) is probably the best studied autoimmune disease caused by autoantibodies against the acetylcholine receptor (AChR) at the neuromuscular junction, subsequently leading to abnormal fatigability and weakness of skeletal muscle. Extraocular muscle weakness with droopy eyelids and double vision is present in about 90% of MG patients, being the initial complaint in about 50%. In approximately 20% of the patients the disease will always be confined to the extraocular muscles. The single most important diagnostic test is the detection of serum antibodies against AChR which is positive in 90% of patients with generalized MG, but only in 65% with purely ocular MG. Electromyographic studies and the Tensilon test are of diagnostic value in clear-cut cases, but may be equivocal in purely ocular myasthenia, especially the latter not rarely producing false-positive results. Treatment response to corticosteroids and anti-cholinesterase agents is satisfactory in many patients with ocular MG, however other immunosuppressive drugs may also be needed. Pathogenetically relevant steps of the underlying autoimmune process have been elucidated during the last few years; nevertheless a number of questions remain open, especially what starts off the autoimmune process, and why are eye muscles so frequently involved in MG?
Neurological complications are a major cause of morbidity and mortality in patients with disseminated malignant melanoma. We have studied and correlated clinical and cerebrospinal fluid (CSF) findings in 20 patients with central nervous system metastases from malignant melanoma including 8 patients with metastatic meningeal melanomatosis (MMM) and 12 patients with solid cerebral metastases (SCM). The putative CSF tumor markers, fibronectin and beta 2-microglobulin, were elevated significantly in MMM but not in SCM patients. A prominent increase in the IgM index, which reflects intrathecal B-cell stimulation, and a rise of IgG index, interleukin-6, and tumor necrosis factor-alpha in MMM patients provide preliminary evidence for a local intrathecal immune response triggered by melanoma cell invasion of the subarachnoid space.
The influence of thymectomy and long term immunosuppression on the phenotype of CD4 T lymphocyte subsets, which were defined by the restricted expression of CD45RA and CD45RO markers, was studied by double immunofluorescence in 29 patients in different clinical stages of generalised myasthenia gravis. In the acute stage of myasthenia, before thymectomy and immunosuppression, no differences in CD4 subsets were observed in the peripheral blood from nine patients and 21 matched controls. Four to seven weeks after thymectomy, there was a slightly decreased proportion of CD4+CD45RO+ (UCHL1+) memory cells (p < 0.05, paired t test). Patients on steroids showed a more pronounced decrease of CD4+CD45RO+ cells suggesting, in addition, a drug-related effect. CD4 subsets (CD45RA, CD45RO, and CD29 positive) in the peripheral blood compartment remained largely stable over 18 to 24 months thereafter. In addition, CD4 subsets were examined in 20 patients with myasthenia gravis who had had a thymectomy between two and 17 years before. With the exception of patients on steroids, there were no differences in CD4 subsets in patients on or off azathioprine. These data did not show any relation of CD4 T cell subsets to the clinical course of myasthenia, or significant changes due to thymectomy, or immunosuppression with azathioprine. These results also complement the authors' clinical experience that thymectomy in adults does not leave a deficit in cell-mediated immunity. The slight change associated with steroid treatment might deserve further attention.
1. To assess the contribution of tubular secretion to the renal excretion of pyridostigmine, and its modification by other cationic drugs, six volunteers were given single oral doses of 60-mg pyridostigmine bromide with and without co-administration of ranitidine or pirenzepine. Renal clearances were determined by h.p.l.c. analysis of pyridostigmine and enzymic measurement of endogenous creatinine in plasma and urine. 2. In patients with myasthenia receiving continuous pyridostigmine therapy, renal clearance values were obtained in the same manner with and without ranitidine (10 patients) or pirenzepine (nine patients) co-medication. 3. Pyridostigmine was not bound to plasma proteins. Its renal clearance averaged 6.65 ml/min per kg (350% of the creatinine clearance) in all subjects, 74% being due to net tubular secretion. 4. Mean values for pyridostigmine renal clearance and for clearance by secretion were decreased in the presence of pirenzepine, but plasma concentrations were not affected significantly. Ranitidine caused a small non-significant decrease of the pyridostigmine clearance in patients. 5. Pyridostigmine had a higher elimination (2 h-1) than the absorption rate constant (0.23 h-1) when administered orally as a non-retarded preparation. 6. The renal clearance of creatinine was slightly increased by pyridostigmine in volunteers and slightly decreased by pirenzepine in the total group of subjects.
The intrathecal immune response in neoplastic meningitis (NM) was studied by quantitation of immune parameters such as immunoglobulin G (IgG); IgM; interleukins (IL) 1, 2, 4, and 6; soluble IL-2 receptors (sIL-2R); interferon gamma (IFNy); tumor necrosis factor-alpha (TNF alpha); and three tumor markers, carcinoembryonic antigen (CEA), alpha-fetoprotein (AFP), and fibronectin (FN), in 47 paired cerebrospinal fluid (CSF) and serum samples from patients with NM from different carcinomas, malignant melanoma, and lymphoma. Elevated IgG and IgM indices, CSF oligoclonal Ig bands, and CSF IL-6 indicated an intrathecal immune activation in most patients with NM. Results for IL-1, IL-2, and IL-4 were always negative. sIL-2R and IFNy were detected occasionally but not associated with specific malignant neoplasms. CSF TNF alpha was detected only in NM from cases of malignant melanoma. None of the immune parameters proved useful for the differentiation of NM from autoimmune or inflammatory conditions. Immune parameters were not correlated with tumor markers CEA, AFP, or FN. Results for AFP were positive only in a case of glioblastoma. CEA was a useful and specific diagnostic parameter in carcinomatous NM. CSF FN levels frequently were elevated but are not specific for NM.
A total of 23 self-expanding metal stents were implanted in 17 patients (12 men, 5 women; mean age 66 [44-83] years) with inoperable malignant obstruction of the oesophagus or the oesophago-gastric junction. A primary success was achieved in all, a good functional result in 16 (94%). There were no complications. In the follow-up period (mean of 15.2 +/- 13 weeks) re-obstruction by the tumour process occurred in three patients. Twelve patients died after a mean survival time of 15.8 +/- 14 weeks. In ten of these the stent was still patent at death, while two had again developed dysphagia. The cumulative patency rate of the stents was 79%. These observations indicate that self-expanding metal stents can achieve satisfactory palliation in dysphagia due to a malignancy. The mortality and morbidity rates of the method seem to be less than those of other palliative measures.
Two patients are described with the triad of tonic pupil, hyporeflexia and segmental anhidrosis (Ross syndrome). Only 18 cases of this syndrome have been reported in the literature so far. While tonic pupil and reduced sweating can be attributed to the affection of postganglionic cholinergic parasympathetic and sympathetic fibres projecting to the iris and sweat glands, respectively, the pathogenesis of diminished or lost tendon jerks remains obscure. To identify the characteristic clinical features, the previous cases of Ross syndrome are reviewed. Recent evidence of subclinical disturbances of sweating in most patients with Adie's syndrome, i.e. tonic pupil and areflexia, casts doubt on the nosological concept of Ross syndrome as a distinct clinical entity.
Serum IgG and IgM antibodies to gangliosides GM1, GM2, GM3, AGM1, GD1a, GD1b and GT1b were determined in 210 patients with different degenerative and inflammatory disorders including motor neuron diseases, peripheral radiculopathies and neuropathies, multiple sclerosis and neuroborreliosis. No single disorder was associated specifically with ganglioside antibodies. No characteristic patterns of ganglioside antibodies were observed in any disease category. However, 32% of all patients had pathological antibody titres to at least one ganglioside. Four patients had pathological IgG and IgM titres for all gangliosides evaluated. They suffered from systemic lupus erythematosus [2], neuroborreliosis and schizophrenia, respectively. The results of this study indicate that the introduction of ganglioside antibody determination as a differential diagnostic test in clinical neurology is only helpful in a few patients with typical lower motor neuron syndromes.
Cerebrospinal fluid (CSF) and serum IgG and IgM antibodies to seven gangliosides were determined in patients with neuroborreliosis (NB) (n = 20), Guillain-Barré syndrome (GBS) (n = 13), and chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) (n = 10). The incidence of elevated antibodies was highest in NB and lowest in CIDP. Correlation between CSF and serum antibodies was only observed for IgG antibodies to GM1, GD1b and GT1b in GBS. The strong IgM antibody reactivity to gangliosides in the CSF of NB patients may be involved in the variety of neurological disorders attributed to Borrelia burgdorferi infection. Since one CIDP and three GBS patients had serologic evidence of prior or concurrent borrelia infection, this infection may belong to the infections that can trigger GBS or CIDP. The lack of specific ganglioside antibody patterns in these four patients suggests that ganglioside antibodies are not the link between Borrelia burgdorferi infection and the demyelination of peripheral nerves in GBS and CIDP.