High-dose intravenous gammaglobulin for chronic inflammatory demyelinating polyneuropathy

We report our preliminary experience of high-dose intravenous gammaglobulin in patients with chronic inflammatory demyelinating polyneuropathy (CIDP) selected for inefficacy or severe side effects of steroid and immunosuppressive treatment. Our treatment proved safe and effective, reversing the disability of CIDP, the improvement being temporally related to the commencement of intravenous high-dose gammaglobulin. The possible mechanisms of action are discussed.

Monoclonal anti-I-A antibody reverses chronic paralysis and demyelination in Theiler's virus-infected mice: critical importance of timing of treatment

Susceptibility to demyelination caused by the WW isolate of Theiler's murine encephalomyelitis viruses is linked to class II genes of the major histocompatibility complex. SJL/J (H-2s) mice, expressing only I-As class II gene products of the major histocompatibility complex, are highly susceptible to Theiler's murine encephalomyelitis virus infection with the WW virus isolate, with chronic paralysis and severe inflammation and demyelination in the central nervous system. The effect of in vivo administration of anti-I-As monoclonal antibodies on Theiler's murine encephalomyelitis virus infection was observed. SJL/J mice were treated in various protocols pre- or postinfection. Anti-I-As monoclonal antibody reversed chronic paralysis and reduced inflammation and demyelination when given after the establishment of persistent infection. The effect was long lasting, but clinical signs, inflammation, and demyelination recurred 2 months after treatment ceased. Anti-I-As antibodies had no effect on viral titers within the central nervous system. The timing of the administration of monoclonal antibodies was critical. Administration of anti-I-As before the establishment of the persistent infection resulted in fatal encephalitis.

A critical review of therapies in acute and chronic inflammatory demyelinating polyneuropathies

Acute and chronic inflammatory demyelinating neuropathies are among the most common treatable neuropathies seen by neurologists. Evidence for effective therapy has only recently been provided by randomized or controlled trials. In the Guillain-Barré syndrome such evidence does not support the use of corticosteroids or immunosuppressive agents. However, when used early in the course, plasma exchange (PE) has been shown to lessen the severity and shorten the duration of the disease; it is indicated only in severely paralyzed patients or those whose rapid deterioration suggests the imminent need for ventilatory support. Some patients with chronic inflammatory demyelinating polyneuropathy (CIDP) respond to corticosteroid therapy or other immunosuppressive agents. PE is also effective in certain patients, but there is no sound evidence to date concerning combined immunosuppression and PE. The rationale of PE in these conditions and whether it is the removal of a toxic factor or the replacement fluid used that is beneficial remains to be clarified.

Effect of hemoperfusion on the course of demyelinization processes: experimental and clinical picture

The experiments on guinea pigs with experimental allergic encephalomyelitis showed, that hemoperfusion through fibrous and granulated activated carbon resulted in stable clinical effect solely on the early stages of the disease (10-11 days after sensitization). At the stage of advanced neurologic symptomatology the hemoperfusion proved effective when performed through binary adsorbent on the base of fibrous activated carbon and immobilized basic encephalitogenous protein. Forty nine patients with multiple sclerosis underwent 2-3 sessions of hemocarboperfusion on SKN coal with 7 day intervals. In patients at the initial stage of the disease the hemocarboperfusion was found to produce a stable and practically complete normalizing effect on the neurologic status. At the advanced stages of the disease the hemosorption eliminates only newly developed symptoms.

Remyelination by oligodendrocytes stimulated by antiserum to spinal cord

The new synthesis of myelin and the proliferation of oligodendrocytes was stimulated by serum from syngeneic mice immunized with homogenized spinal cord (SCH). Treatment with this antiserum produced a 10-fold increase in the area of remyelination in spinal cords that had become demyelinated previously as a result of infection by Theiler's murine encephalomyelitis virus. Inflammation was decreased in regions of white matter that showed remyelination. Oligodendrocytes exposed to anti-SCH in vitro incorporated three to five times more [3H]thymidine than resting cells did and expressed more myelin basic protein in their cytoplasm, suggesting stimulation of myelinogenesis. Thus, there is a factor present in anti-SCH antiserum that stimulates central nervous system-type remyelination. This finding may provide clues for the therapy of patients with demyelinating disorders such as multiple sclerosis.

Effect of cyclosporin A, silica quartz dust, and protease inhibitors on virus-induced demyelination

Treatment with cyclosporin A, from the time of virus infection, suppressed inflammation and demyelination in the spinal cord of SJL/J or ASW(H-2s) mice persistently infected with Theiler's murine encephalomyelitis virus. Demyelination was not decreased if treatment was given after inflammation was established. The decrease was independent of serum titers of immunoglobulin G to purified viral antigen but did correlate with decreased proliferation of T lymphocytes to virus and myelin antigens. Silica quartz dust, a direct toxin of macrophages, suppressed demyelination and inflammation if begun at time of virus infection. No therapeutic effect was seen with inhibitors of plasminogen activators or other neutral proteases found primarily in macrophages.

[Central pontine myelinolysis]

A review is given on symptoms, etiology, pathogenesis and prognosis of central pontine myelinolysis (CPM). Since 1959, 315 cases of CPM have been reported in world literature, 41 per cent of the patients described developed their neurological symptoms in the course of chronic alcoholism. In about 32 per cent CPM was connected with electrolyte disturbance, especially hypo- or hypernatremia. Beside the complications of alcoholism, accompanying diseases were malignancies (9%) infections of the lung (10%) and diseases of the central nervous system (7%). Current theories about etiology and pathogenesis of CPM are reviewed with special reference to the syndrome of inappropriate secretion of the antidiuretic hormone (IADH). Own experiences with clinical diagnosis of CPM are reported. Seven patients with neurological symptoms in hyponatremia have been seen prospectively during one year. In three cases clinically, in one patient neuropathologically the diagnosis of CPM was made.

Assessment of therapeutic plasmapheresis in demyelinating neurologic disorders

Considerable controversy exists with regard to therapeutic efficacy of plasmapheresis in the immune-mediated demyelinating disorders of the peripheral and central nervous system: acute inflammatory polyneuropathy (Guillain-Barré syndrome), chronic inflammatory demyelinating polyneuropathy, and multiple sclerosis. In an effort to establish specific situations where plasmapheresis was of therapeutic value, we reviewed the experience at Southwestern Medical School, University of Texas Health Science Center at Dallas, and that published in the literature. In acute inflammatory demyelinating polyneuropathy (Guillain-Barré syndrome), plasmapheresis may prevent progression of the illness, and it significantly increases the rate of recovery. For patients with chronic inflammatory polyneuropathy, plasmapheresis has produced clinical improvement in 50% of corticosteroid-refractory patients. The use of plasmapheresis in patients with acute or chronic progressive multiple sclerosis still remains controversial.

Myelination by transplanted fetal and neonatal oligodendrocytes in a dysmyelinating mutant

Demyelination is a major feature of CNS injury and disease, including multiple sclerosis. To examine the potential for myelination by transplanted oligodendrocytes, initially described by Gumpel et al., we have transplanted neonatal cortex of mice with normal myelin into a dysmyelinating mutant, the shiverer mouse. We have found that oligodendrocyte precursors mature and synthesize myelin following transplantation. Immunostaining with antibodies to myelin basic protein (MBP), neurofilament protein and glial fibrillary acidic protein, demonstrates myelination both within the graft and extending out into the host, axonal sprouting from the graft which parallels the MBP-reactivity, and minimal astrocytic proliferation in response to the transplant.

Partial suppression of Theiler's virus-induced demyelination in vivo by administration of monoclonal antibodies to immune-response gene products (Ia antigens)

In vivo administration of monoclonal antibody reactive with major histocompatibility complex-encoded Ia molecules (I-As) partially suppressed inflammation and demyelination in the spinal cord of SJL/J (H-2s) mice persistently infected with Theiler's murine encephalomyelitis virus. Demyelination was decreased if antibody was given at the time of virus inoculation or after inflammation had been established in the spinal cord. The decrease in demyelination was independent of isolation of infectious virus from the CNS or of serum titers of immunoglobulin to purified viral antigen. Thus, Theiler's virus-induced demyelination is mediated, in part, by immune cells that carry Ia class II molecules.

Plasma exchange in chronic inflammatory demyelinating polyradiculoneuropathy

Plasma exchange has been reported to be efficacious in chronic inflammatory demyelinating polyradiculoneuropathy. We performed a prospective double-blind trial in which patients with static or worsening disease were randomly assigned to plasma exchange (n = 15) or to sham exchange (n = 14) for three weeks. After three weeks, we observed statistically significant differences in combined measurements of nerve conduction (total, motor, proximal, velocity, and amplitude) favoring patients who had received plasma exchange. Improvement to a greater degree than for any patient receiving sham exchange was detected in the neurologic-disability score in five patients (P = 0.025) and in subset scores for weakness and reflex in four patients (P less than 0.057). We conclude that for some patients with chronic inflammatory demyelinating polyradiculoneuropathy, plasma exchange has an ameliorating effect on neurologic dysfunction and nerve conduction, but in others no improvement is observed. Because plasma was replaced with normal serum albumin, a humoral factor or factors may have a role in the neurologic deficit of this disorder.

The interaction of Schwann cells with CNS axons in regions containing normal astrocytes

On occasions retinal axons can be myelinated by Schwann cells. In the present experiments cultured autologous Schwann cells were injected into the optic disc of adult cats and the extent of Schwann cell myelination determined. Little if any Schwann cell myelination of retinal ganglion cell axons developed. Schwann cells were also injected into lesions in the cerebral cortex induced by ethidium bromide. In this site some Schwann cell remyelination was detected, but it was restricted to areas next to regions of malacia induced by the injection procedure. It was concluded that astrocyte responses, limit Schwann cell myelination and remyelination in normal tissue by excluding Schwann cells from the CNS compartment, and induce changes in chronically demyelinated and amyelinated axons which may affect myelination.

The use of cultured autologous Schwann cells to remyelinate areas of persistent demyelination in the central nervous system

Areas of persistent demyelination were created in the dorsal columns of the cat spinal cord by injecting ethidium bromide into white matter which had previously been exposed to 40 Grays of X-irradiation. In the centre of such lesions demyelinated axons occurred in a glial-free area while axons next to normal tissue were separated by astrocyte processes. No remyelination occurs in such lesions (Blakemore 1984). Autologous Schwann cells and fibroblasts cultured from a peripheral nerve biopsy were injected into such lesions and the extent of Schwann cell remyelination examined. Only lesions injected with viable cells showed remyelination by Schwann cells; in no lesion were all the demyelinated axons remyelinated. Three forms of association of Schwann cell with axons were detected. In the centre of the lesions Schwann cells either remyelinated axons around or near to blood vessels, or lay next to demyelinated axons and did not form myelin. Schwann cell remyelination was also detected in the astrocyte-containing areas around the edges of some lesions. It was concluded that the extent of Schwann cell remyelination was influenced by the mode of entry of the cells into the lesion and by the architecture of the lesion. The presence or absence of stable extracellular matrix is believed to be the prime factor which influenced Schwann cell remyelination. The relevance of these observations to artificial repair of the lesions of multiple sclerosis is discussed.

A runs test based on run lengths

A procedure is proposed for testing the hypothesis that Bernoulli trials (successes and failures) are independent with common probability of success. Equivalently, the procedure may be used to test the hypothesis that the arrangement of a fixed number of successes and failures was determined randomly. The procedure is based on a weighted linear combination of the variances of run lengths of successes and failures. It is shown to have desirable asymptotic properties and to be generally more powerful than the usual runs test, while preserving computational simplicity.

Paraproteinemia associated with demyelinating polyneuropathy or myositis: treatment with plasmapheresis and immunosuppressive drugs

Four patients with chronic, progressive demyelinating peripheral polyneuropathy were found to have paraproteinemia. Two of the patients had multiple myeloma [both immunoglobulin (Ig)G lambda]. The other two had benign gammopathies: one of IgG kappa type and the other one with marked polyclonal elevation of IgM. Immunofluorescence studies revealed deposits of the abnormal serum immunoglobulin along the myelin sheaths in two of the patients in whom sural nerve biopsies were performed. All four patients were treated with plasmapheresis in combination with immunosuppressive drugs. Favorable responses to the therapy was observed in all four patients, but the degree of response varied from patient to patient. Two patients who presented clinical and electromyographic findings consistent with polymyositis were found to have serum IgG kappa M components. Immunofluorescence studies performed on muscle biopsy material from both patients revealed deposits of the abnormal serum paraprotein along the sarcolemmal basement membrane. A treatment course of plasmapheresis and immunosuppressive drugs resulted in a sustained increase of muscle strength in both patients.

Lymphocytaplasmapheresis in Devic's syndrome

A pregnant 26-year-old woman with Devic's syndrome manifesting as paraplegia and visual loss was treated with multiple courses of lymphocytaplasmapheresis. Clinical improvement was temporally related to the lymphocytaplasmapheresis. She relapsed when treatment was stopped and improved with reinstitution of therapy. Thereafter, further treatments were not required and she delivered a normal infant.