The antidepressant rolipram suppresses cytokine production and prevents autoimmune encephalomyelitis

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.

Ocular myasthenia gravis. A critical review of clinical and pathophysiological aspects

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?

Renal clearance of pyridostigmine in myasthenic patients and volunteers under the influence of ranitidine and pirenzepine

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.

Intrathecal IgM response in disseminated cerebrospinal metastasis from malignant melanoma

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.

Thymectomy and azathioprine have no effect on the phenotype of CD4 T lymphocyte subsets in myasthenia gravis

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.

Ganglioside antibodies: a lack of diagnostic specificity and clinical utility?

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.

Humoral CSF parameters in the differential diagnosis of hematologic CNS neoplasia

Cerebrospinal fluid (CSF) and serum samples of 20 patients with central nervous system manifestations of hematological malignancies including primary cerebral lymphoma (n = 5) and disseminated non-Hodgkin lymphoma (n = 7) were examined for albumin, IgG, IgM, fibronectin, beta 2-microglobulin, interleukin-6, soluble interleukin-2 receptor, tumor necrosis factor alpha, and oligoclonal immunoglobulin bands. Although a broad range of abnormalities were detected, no reliable CSF parameter for the diagnosis of leptomeningeal spread from hematological neoplasias could be identified. An analysis of 61 repeat lumbar punctures added little to the findings of the first CSF examinations. Currently, immunochemical studies of CSF cell surface markers and early biopsy have probably more clinical value than the determination of the humoral CSF parameters included in this study. However, analysis of cytokine synthesis by single CSF cells using molecular biology techniques may improve the differential diagnosis of hematological neoplasia of the brain and spinal cord in the future.

Influence of gangliosides on experimental allergic neuritis

The development of myelin-induced experimental allergic neuritis (EAN) in Lewis rats can be depressed and delayed by adding a ganglioside mixture (GM1, GD1a, GD1b, GT1b) to the immunization compound; however, gangliosides may enhance the induction of adjuvant arthritis. Antibodies against multiple gangliosides are produced in rats after immunization with gangliosides after addition of myelin, but only low titers can be detected in animals immunized with myelin and complete Freund's adjuvant alone. We conclude that this antibody production is not the result of peripheral nerve inflammation but depends rather from external applied gangliosides.

[Intrathecal immune response in meningeosis neoplastica: IgG, IgM, oligoclonal bands and cytokines]

Owing to improved systemic control of widespread malignancy, neurological complications have become a major outcome factor and determinant of life quality in oncological patients. While solitary cerebrospinal metastases are often amenable to surgical and radiological treatment, the management of diffuse leptomeningeal neoplasia, mostly using combined radiochemotherapy, is still very difficult. Immunomodulative approaches represent a therapeutic alternative with increasing potential. We have analysed the natural immune response to leptomeningeal tumor invasion in 43 Patients by assessing cerebrospinal fluid (CSF) levels of albumin, IgG, IgM, interleukins (IL) 1, 2, 4 and 6, soluble IL-2 receptor (sIL-2R), interferon gamma (IFN gamma), tumor necrosis factor alpha (TNF alpha), and the tumor markers, carcinoembryonic antigen (CEA) and alphafetoprotein (AFP). In most patients, either elevated IgG index, IgM index, CSF IL-6, or detection of CSF oligoclonal immunoglobulin bands indicated a host reaction against tumor cells. IL-1, IL-2, and IL-4 were never detected in CSF or serum. sIL-2R and IFN gamma were rarely detected and were not associated with specific malignancies. CSF TNF alpha was only detected in melanoma patients and may be a specific indicator of that neoplasm. No correlation was found between levels of the tumor markers, CEA and AFP, and parameters of the immune response such as IgG, IgM or IL-6. The demonstration of intrathecal immune activation in a majority of patients with leptomeningeal neoplasia may offer a new option for immunomodulative oncological therapy.

Tonic pupil, areflexia, and segmental anhidrosis: two additional cases of Ross syndrome and review of the literature

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.

Tumor cell dissemination triggers an intrathecal immune response in neoplastic meningitis

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.

Tumour necrosis factor-alpha in malignant melanomatous meningitis

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Are CSF or serum ganglioside antibodies related to peripheral nerve demyelination in neuroborreliosis, Guillain-Barré syndrome, or chronic inflammatory demyelinating polyradiculoneuropathy?

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.

Acetylcholine receptor-reactive T lymphocytes from healthy subjects and myasthenia gravis patients

Peripheral blood lymphocytes from 23 of 114 (20%) myasthenia gravis (MG) patients showed positive T-cell proliferative responses to native acetylcholine receptor (AChR) purified from the electric fish Torpedo, compared with two of 25 (8%) healthy or other neurologic disease controls. Responsiveness appeared to fluctuate seasonally. Long-term T-cell lines and clones could be selected as readily from the two healthy responders as from the MG cases and showed similar culture behavior, CD4+ phenotype, and HLA class II restrictions. One clone from a control cross-reacted with recombinant human AChR alpha chain (r37-429A) and with the synthetic peptide 125-143(S-S) from its sequence. Both these human antigens stimulated primary proliferative responses at substantially higher frequencies (26 to 59%) than native xeno-AChR--in both patients and controls--demonstrating that truly autoreactive T cells are not inevitably deleted during normal T-cell development.

Comparative analysis of cytokine patterns in immunological, infectious, and oncological neurological disorders

Interleukins (IL) 1, 2, 4, 6 and soluble IL-2 receptor (sIL-2R), interferon-gamma (IFN-gamma), and tumor necrosis factor-alpha (TNF-alpha) were measured in CSF and serum from patients with relapsing-remitting and chronic multiple sclerosis, Guillain-Barré syndrome, chronic inflammatory demyelinating polyradiculoneuropathy, HIV infection, bacterial meningitis, viral encephalitis, meningeal carcinomatosis, hematologic meningeal malignancies, and disseminated melanoma. Our findings suggest that monitoring of disease activity in neuroimmunologic disorders by means of IL-1 beta, IL-2, sIL-2R, or IL-4 determination will not prove useful. IL-6, on the other hand, indicates relapse in multiple sclerosis and active disease in Guillain-Barré syndrome and meningeal carcinomatosis. High CSF TNF-alpha in metastatic melanoma and frequent detection in CSF of the multifunctional B-cell growth factor, IL-6 (27/30) and oligoclonal immunoglobulin bands (33%) in meningeal carcinomatosis confirm an intrathecal immune response in disseminated leptomeningeal neoplasia which might be amenable to therapeutic immunomodulation.

Cerebrospinal fluid interleukins, immunoglobulins, and fibronectin in neuroborreliosis

Intrathecal synthesis of IgM and IgG, oligoclonal immunoglobulin bands, and the levels of fibronectin, soluble interleukin 2 receptor, interleukin 6, and tumor necrosis factor alpha were investigated with the use of enzyme-linked immunosorbent assay in 46 paired cerebrospinal fluid and serum samples from 32 patients with meningopolyradiculoneuritis due to Borrelia burgdorferi (Lyme borreliosis stage 2). Cerebrospinal fluid and serum interleukin 6, although not specific for neuroborreliosis, were good indicators of disease activity, while the serum soluble interleukin 2 receptor level was only mildly elevated. Tumor necrosis factor alpha was never detected in cerebrospinal fluid or serum specimens, and cerebrospinal fluid IgM, IgM index, and cerebrospinal fluid IgM/cerebrospinal fluid IgG ratios were significantly higher than in all other neuroimmunologic disorders evaluated and may be valuable diagnostic indicators for neuroborreliosis. The estimation of intrathecally synthesized IgG and IgM fractions for the differential diagnosis of neuroimmunologic disorders did not add to IgG and IgM index calculations.

Neurosarcoidosis without systemic sarcoidosis

Neurosarcoidosis is a well-recognised complication of systemic sarcoidosis but diagnosis may be difficult if there is no clear evidence of an extracerebral manifestation of the disease. We present the case of a 42-year-old woman with clinical features characteristic of cerebral sarcoidosis including tetraparesis, diabetes insipidus, diencephalic hyperphagia, personality changes, and memory loss. Diagnosis was supported by cerebrospinal fluid (CSF) findings and magnetic resonance imaging (MRI): CSF showed mild lymphocytic pleocytosis, intrathecal production of IgG without oligoclonal bands, and a raised level of lysozyme. MRI revealed multiple contrast-enhanced granulomas at the base of the brain with partial involvement of diencephalic and mesencephalic structures and parts of the spinal cord. There was no evidence of systemic manifestation of sarcoidosis. Administration of corticosteroids led to improvement of the symptoms.

Myasthenic thymus and thymoma are selectively enriched in acetylcholine receptor-reactive T cells

We compared T-cell proliferative responses to acetylcholine receptor (AChR) and to purified protein derivative (PPD) (of tuberculin) of hyperplastic thymus, thymoma, and blood cells from patients with myasthenia gravis (MG). Hyperplastic MG thymus cells gave significantly higher and more consistent responses to AChR than parallel cultures of autologous blood cells, whereas responses to PPD showed an opposite trend. Thus there was a preferential localization of AChR-reactive T cells in the hyperplastic MG thymus. Furthermore, there was a strong correlation between blood and thymus cell responses to PPD (but not to AChR), arguing that the hyperplastic MG thymus contains a sample of sensitized peripheral T cells. By contrast, both AChR- and PPD-responsive T cells were almost undetectable in thymus from nonmyasthenic patients, which is evidently much less receptive to circulating T cells. Cells from MG thymomas showed the highest stimulations by AChR but did not consistently react to PPD. However, the uninvolved thymus adjacent to these thymomas behaved almost identically to the hyperplastic samples described above. Our interpretation is that AChR-specific T cells are initially sensitized in the MG thymoma but are selectively trapped in the hyperplastic thymus after being primed elsewhere.

Increased intrathecal synthesis of fibronectin in bacterial and carcinomatous meningitis

Immunoreactive fibronectin (Fn) was quantified in paired cerebrospinal fluid (CSF) and serum samples from patients with bacterial meningitis (n = 46), tick-borne encephalitis (TBE) (n = 6), HIV infection (n = 6), Guillain-Barré syndrome (n = 5), carcinomatous meningitis (n = 11), multiple sclerosis (n = 15), disk disease (n = 11), and controls (n = 28). A highly significant elevation of CSF Fn was found in bacterial meningitis, TBE, and carcinomatous meningitis. There were no significant differences in serum Fn between any of the groups. An Fn index to estimate the rate of intrathecal Fn synthesis reached the highest value in bacterial meningitis. Our findings suggest that CSF Fn may be an indicator of adequate host reaction and tissue repair. For diagnostic purposes, the determination of CSF Fn probably does not add much to routine CSF laboratory tests.

Central pontine myelinolysis associated with low potassium levels in alcoholism

Two patients with chronic alcohol abuse and central pontine myelinolysis are described. One developed a Korsakoff syndrome 2 days before admission to our hospital and the other showed signs of a incipient delirium without Korsakoff syndrome. Diagnosis of incipient central pontine myelinolysis was based on acute brain-stem dysfunction, serum electrolyte disturbances, malnutrition with vitamin B1 (thiamine), B6 (pyridoxine) and B12 (cyanocobalamin) deficiency in combination with typical neuroradiological findings. Hypokalaemia but no disturbance in serum sodium levels was found in both patients. After correction of hypokalaemia and vitamin deficiency the patients showed complete recovery of neurological and neuropsychological function. The findings are interpreted as suggesting that disturbances in serum potassium levels as well as rapid correction of hyponatraemia may be associated with pontine swelling and dysfunction which, if undetected, leads to central pontine myelinolysis.

Variable corticosteroid sensitivity of thymic cortex and medullary peripheral-type lymphoid tissue in myasthenia gravis patients: structural and functional effects

The thymus has been studied in myasthenia gravis patients to assess the effects of previous immunosuppression on total yields of cell suspension, immunohistology and culture responses. The reduction in cell yields by pretreatment with corticosteroid was very variable. In 16 of 32 cases, cortical, medullary and total cell numbers were all greatly reduced ('depleted cases'), whereas in the others, they were within or near the typical range for untreated myasthenics. Cortical thymocytes were even more depleted than precursor thymic blasts. Thus the interpatient differences in sensitivity to corticosteroid recently described for mature T cells also affected immature cortical thymocytes and their differentiating medullary progeny. In the medulla, mature (CD3+) T lymphocytes and germinal centres were enriched by the loss of cortex and appeared relatively healthy, but somewhat depopulated. Concomitantly, in-vitro T-cell responses to acetylcholine receptor (AChR) and production of anti-AChR antibody and total IgG by thymic cells were usually well within the typical range (assessed per 10(6) cells). Moreover, the total productivity of the entire thymus was reduced almost entirely by the cellular depopulation rather than by decreased function per surviving cell. Thus the main actions of this alternate day therapy with corticosteroids were apparently on total peripheral cell numbers, and perhaps on activated cells and effector mechanisms too, and its thymic effects were inessential.

T-cell reactivity in myasthenia gravis

In a proliferation assay, peripheral blood lymphocytes (PBL) from a relatively small proportion of myasthenia gravis (MG) patients and from controls responded to Torpedo acetylcholine receptor (T-AChR), which shows approximately 75% homology with the human AChR. Over 50% of MG patients responded to recombinant human AChR alpha-subunit (r37-437) however, compared with 9% of controls. A proportion of MG PBL respond to synthetic peptides of the extracellular portion of the human alpha-subunit, but only MG patients (18%) responded to the juxta-membrane sequence p257-269. MG T-cell lines raised against native T-AChR failed to respond to the synthetic peptides. These results underline the need to use human AChR sequences to test relevant T-cell reactivity in MG. T-cell lines raised from three MG patients to human alpha-subunit r37-437 have shown Stimulation Index (SI) values of 3.5-22. Three clones derived from one of these had SI values of 100-500. Preliminary testing of responsiveness in one of these clones showed reactivity to several recombinant polypeptides including r37-437 and r37-181, as in the parent line. The epitope(s) within this latter sequence have not yet been identified, but the experimental approach used here should make it possible to define critical T-cell epitopes in MG, and to determine their functional relevance by investigating the ability of AChR-reactive T-cell clones to provide specific help in anti-AChR antibody production.

A juxta-membrane epitope on the human acetylcholine receptor recognized by T cells in myasthenia gravis

T cell proliferative responses to synthetic peptides taken from the human nicotinic acetylcholine receptor (AChR) alpha-chain sequence, or to whole AChR purified from electric fish (Torpedo marmorata), have been studied, using blood, thymus, and lymph node cells, from 34 patients with myasthenia gravis (MG) and 17 controls mostly with other neurological diseases. Peptides were selected because they contained amino acid motifs that recur in most defined T cell epitopes. Peptide 257-269 (from the extracellular loop of the AChR alpha-chain between the second and third trans-membrane domains) stimulated cells from six patients and no controls. Peptides from region 125-143 (from the main extracellular 1-210 stretch), which is thought to be an important T cell epitope in rats, provoked responses in 26% of patients and 41% of controls. Two patients responded both to these peptides and to peptide 257-269, thereby implying some heterogeneity of their reacting T cells. Whereas the initial blood T cell samples sometimes responded both to Torpedo AChR and to the 125-143 peptides, T cell lines selected with either antigen subsequently showed no response to the other. This observation suggests that it may be essential to use human AChR sequences for studying truly autoreactive T cells in MG. Finally, no strong association was found between any of the responses to peptides and the HLA types of the responding individuals.