Effect of intravenous immunoglobulin in Lambert-Eaton myasthenic syndrome with small-cell lung cancer: correlation with the titer of anti-voltage-gated calcium channel antibody

Neuroprotective Effect of Polyvalent Immunoglobulins on Mouse Models of Chemotherapy-Induced Peripheral Neuropathy

The occurrence of neuropathic pain in chemotherapy-induced peripheral neuropathy (CIPN) is a major dose-limiting effect of many commonly-used anticancer agents. Polyvalent human immunoglobulins (hIg), used in the treatment of several peripheral neuropathies, may alleviate neuropathic pain. The aim of this project was to investigate the preventive effect of hIg in two mouse models of CIPN, induced by vincristine (VCR, 100 µg/kg/d) and oxaliplatin (OXP, 6 mg/kg/3d). Human Ig were administered one day before the first injection of chemotherapy. The onset of CIPN and effects of hIg were assessed via functional tests and morphological analyses of sensory nerves. To evaluate the effect of hIg on chemotherapy cytotoxicity, viability assays were performed using hIg (0 to 12 mg/mL) combined with anticancer agents on human cancer cell lines. The preventive treatment with hIg alleviated tactile hypersensitivity and nerve injuries induced by VCR. It also alleviated tactile/cold hypersensitivities and nerve injuries induced by OXP. Treatment with hIg did not affect the cytotoxicity of either chemotherapy. Furthermore, in combination with VCR, hIg potentiated chemo-induced cell death. In conclusion, hIg is a promising therapy to prevent the onset of CIPN and potentiate chemotherapy effect on cancer, reinforcing the interest in hIg in the management of CIPN.

Autoimmune paraneoplastic syndromes associated to lung cancer: A systematic review of the literature Part 4: Neurological paraneoplastic syndromes, involving the peripheral nervous system and the neuromuscular junction and muscles

The development of new immune treatment in oncology and particularly for lung cancer may induce new complications, particularly activation or reactivation of auto-immune diseases. In this context, a systematic review on the auto-immune paraneoplastic syndromes that can complicate lung cancer appears useful. This article is the fourth of a series of five and deals mainly with neurological paraneoplastic syndromes involving the peripheral nervous system and the neuromuscular junction and muscles.

Synaptic Pathophysiology and Treatment of Lambert-Eaton Myasthenic Syndrome

Lambert-Eaton myasthenic syndrome (LEMS) is an autoimmune disease that disrupts the normally reliable neurotransmission at the neuromuscular junction (NMJ). This disruption is thought to result from an autoantibody-mediated removal of a subset of the P/Q-type Ca(2+) channels involved with neurotransmitter release. With less neurotransmitter release at the NMJ, LEMS patients experience debilitating muscle weakness. The underlying cause of LEMS in slightly more than half of all patients is small cell lung cancer, and cancer therapy is the priority for these patients. In the remaining cases, the cause of LEMS is unknown, and these patients often rely on symptomatic treatment options, as there is no cure. However, current symptomatic treatment options, such as 3,4-diaminopyridine (3,4-DAP), can have significant dose-limiting side effects; thus, additional treatment approaches would benefit LEMS patients. Recent studies introduced a novel Ca(2+) channel agonist (GV-58) as a potential therapeutic alternative for LEMS. Additionally, this work has shown that GV-58 and 3,4-DAP interact in a supra-additive manner to completely restore the magnitude of neurotransmitter release at the NMJs of a LEMS mouse model. In this review, we discuss synaptic mechanisms for reliability at the NMJ and how these mechanisms are disrupted in LEMS. We then discuss the current treatment options for LEMS patients, while also considering recent work demonstrating the therapeutic potential of GV-58 alone and in combination with 3,4-DAP.

Treatment for Lambert-Eaton myasthenic syndrome

BACKGROUND

Lambert-Eaton myasthenic syndrome (LEMS) is an autoimmune disorder of neuromuscular transmission. Treatments attempt to overcome the harmful autoimmune process, or improve residual neuromuscular transmission

OBJECTIVES

The objective was to examine the efficacy of treatment in Lambert-Eaton myasthenic syndrome.

SEARCH STRATEGY

We searched the Cochrane Neuromuscular Disease Group Specialized Register (12 October 2010), the Cochrane Central Register of Controlled Trials (CENTRAL) (12 October 2010, Issue 4 2010 in the Cochrane Library), MEDLINE (January 1966 to September 2010) and EMBASE (January 1980 to September 2010).

SELECTION CRITERIA

All randomised or quasi-randomised trials of adults and children with a diagnosis of Lambert-Eaton myasthenic syndrome, with or without small-cell lung cancer, receiving any form of pharmacological or physical treatment.

DATA COLLECTION AND ANALYSIS

All authors independently assessed studies for inclusion and extracted data. Study authors were contacted for missing information when possible.

MAIN RESULTS

Four controlled trials of 3,4-diaminopyridine compared with placebo in a total of 54 participants with Lambert-Eaton myasthenic syndrome were eligible: three cross-over trials and one parallel group. Two were added at this update. One of these trials also assessed pyridostigmine in conjunction with 3,4-diaminopyridine. A further cross-over trial compared intravenous immunoglobulin (IVIg) to placebo in nine participants.Four trials of 3,4-diaminopyridine reported significant improvement in the primary outcome, muscle strength score, or myometric limb measurement for between hours and a week following treatment, and significant improvement in resting compound muscle action potential (CMAP) amplitude following 3,4-diaminopyridine, compared with placebo.A meta-analysis of the primary endpoint showed Quantitative Myasthenia Gravis (QMG) muscle score assessed between three and eight days was likely to improve by a mean of 2.44 points (95% confidence interval 3.6 to 1.22). Meta-analysis of the secondary endpoint CMAP amplitude also showed a mean improvement of 1.36 mV (95% confidence interval 0.99 to 1.72) over the same period. The risk of bias was determined to be low, and quality of evidence moderate to high.A single cross-over trial reported significant improvement in myometric limb strength and non-significant improvement in mean resting CMAP amplitude with IVIg compared to placebo. Clinical improvement lasted for up to eight weeks.

AUTHORS' CONCLUSIONS

Limited but moderate to high quality evidence from randomised controlled trials showed that over days 3,4-diaminopyridine, or for up to 8 weeks IVIg, improved muscle strength scores and CMAP amplitudes in participants with Lambert-Eaton myasthenic syndrome. There are insufficient data at present to quantify this effect. Other possible treatments have not been tested in randomised controlled trials.

Available treatment options for the management of Lambert-Eaton myasthenic syndrome

Lambert-Eaton myasthenic syndrome is a rare, but reasonably well-understood, antibody-mediated autoimmune disease that is caused by serum auto-antibodies and results in muscle weakness and autonomic dysfunction. One half of the patients have an idiopathic form, the other half a tumour-associated form of the disease. Three randomised trials and a large number of smaller clinical studies have resulted in a number of drugs becoming available for the treatment of Lambert-Eaton myasthenic syndrome. Several drugs are available for the symptomatic treatment of the disease, including guanidine, aminopyridines or acetylcholinesterase inhibitors. Other therapies aim to deplete the serum autoantibodies or to suppress the immune system. For this purpose, immunomodulating strategies, such as intravenous immunoglobulins or plasmapheresis, or several immunosuppressive agents are available. Chemotherapy has successfully ameliorated the course of disease in Lambert-Eaton myasthenic syndrome patients with an underlying tumour.

Intravenous immunoglobulin therapy in neurological diseases during pregnancy

Immunological changes during pregnancy influence the course of neurological autoimmune diseases in different ways. In case of pregnancy immunomodulatory standard therapies such as interferon-beta, glatiramer acetate,monoclonal antibodies and cytostatics mostly should be discontinued. In those cases intravenous immunoglobulin (IVIg) therapy might be an alternative. In some diseases, contemporary publications describe positive therapeutic effects on the course of disease during or after pregnancy.

IVIg in myasthenia gravis, Lambert Eaton myasthenic syndrome and inflammatory myopathies: current status

Intravenous immunoglobulin (IVIg) is an effective tool for the treatment of diseases with immune pathogenesis. This article reviews the current knowledge of the benefits of treating with IVIg patients with myasthenia gravis (MG), Lambert Eaton myasthenic syndrome (LEMS), dermatomyositis (DM), polymyositis (PM) and inclusion body myositis (IBM). Myasthenia gravis: Treatment of MG with IVIg was reported to be beneficial in a number of case series and two randomised controlled trials, in which efficacy was measured by clinical improvement using myasthenic muscle score and decrease in anti-acetylcholine receptor antibodies (AchRAb). According to the results, IVIg could be recommended for crisis and severe exacerbation. In many other clinical conditions, such as response to treatment of mild or moderate exacerbation, changes in steroid dosage and before thymectomy, IVIg has also been reported to be helpful, but no controlled trials to confirm its efficacy have been performed. Lambert-Eaton myasthenic syndrome: A placebo-controlled crossover study reported a significant clinical improvement in the amplitude of the resting CMAP following IVIg treatment. Further experience from case reports also indicates that IVIg is useful in patients with LEMS, both as a short- and long-term treatment, especially when immunosuppressive drugs are not fully effective. Inflammatory myopathies/dermatomyositis: In a double-blind placebo-controlled crossover trial in patients with DM resistant to other treatments, IVIg was shown to produce a significant increase of muscle strength as well as a marked improvement in immunopathological parameters in repeated muscle biopsies (before and after IVIg). Thus, IVIg is an important therapy in patients with DM resistant to other conventional therapies. Polymyositis: No randomised trials have been undertaken. One study showed clinical improvement and a reduction in the need of prednisone in patients with chronic refractory PM. Inclusion body myositis: Three controlled trials showed some muscle strength improvement, although the changes did not reach statistical significance. However improvement in swallowing was repeatedly observed, suggesting that some patients with severe dysphagia may derive a modest benefit from IVIg therapy.

CONCLUSION

Controlled trials indicate that in MG, LEMS, and DM, IVIg at a total dose of 2 g/kg is a highly useful therapy. Uncontrolled trials and case reports indicate benefit in many different clinical situations, but further clinical investigation is required.

Treatment for Lambert-Eaton myasthenic syndrome

BACKGROUND

Lambert-Eaton myasthenic syndrome is an autoimmune presynaptic disorder of neuromuscular transmission. Treatments attempt to overcome the harmful autoimmune process, or to improve residual neuromuscular transmission, in order to reverse muscle weakness.

OBJECTIVES

The objective was to examine the efficacy of treatment in Lambert-Eaton myasthenic syndrome.

SEARCH STRATEGY

We searched the Cochrane Neuromuscular Disease Group trials register (December 2004), MEDLINE (January 1966 to December 2004) and EMBASE (January 1980 to December 2004), and checked bibliographies and contacted authors to identify additional published or unpublished data.

SELECTION CRITERIA

All randomised or quasi-randomised trials of adults and children with a diagnosis of Lambert-Eaton myasthenic syndrome, with or without small-cell lung cancer, receiving any form of pharmacological or physical treatment. The primary outcome measure was change in muscle strength scale score (Quantitative Myasthenia Gravis score), or limb muscle strength measured by myometry. The secondary outcome measure was improvement in the mean amplitude of the resting compound muscle action potentials. The mean amplitude used was the mean of all muscles tested.

DATA COLLECTION AND ANALYSIS

We identified three randomised controlled trials.

MAIN RESULTS

Two controlled trials of the effects of 3,4-diaminopyridine compared with placebo in a total of 38 patients with Lambert-Eaton myasthenic syndrome were eligible, one of which was of crossover design. A third crossover trial compared intravenous immunoglobulin treatment to placebo in nine patients. Two trials of 3,4-diaminopyridine reported a significant improvement in muscle strength score, or myometric limb measurement following treatment, and a significant improvement in resting compound muscle action potential amplitude following 3,4-diaminopyridine, compared with placebo.A meta-analysis of the primary endpoint results was not possible because of marked differences in primary outcome measures. However, a meta-analysis of the secondary endpoint was possible. The overall weighted mean difference was 1.80 mV (95% confidence interval 0.82 to 2.78), favouring treatment.A crossover trial reported a significant improvement in myometric limb strength and a non-significant improvement in change in the mean resting compound muscle action potential amplitude when patients received intravenous immunoglobulin compared to placebo infusions. Clinical improvement lasted for up to eight weeks.

AUTHORS' CONCLUSIONS

Limited evidence from randomised controlled trials showed that either 3,4-diaminopyridine or intravenous immunoglobulin improved muscle strength scores and compound muscle action potential amplitudes in patients with Lambert-Eaton myasthenic syndrome. There are insufficient data at present to quantify this treatment effect. Other possible treatments have not been tested in randomised controlled trials.

Treatment for Lambert-Eaton myasthenic syndrome

BACKGROUND

Lambert-Eaton myasthenic syndrome is an autoimmune presynaptic disorder of neuromuscular transmission. Treatments have attempted to overcome the harmful autoimmune process, or to improve residual neuromuscular transmission, in order to reverse the principal neurological symptom of muscle weakness.

OBJECTIVES

The objective was to examine the efficacy of all forms of treatment in Lambert-Eaton myasthenic syndrome.

SEARCH STRATEGY

We searched the Cochrane Neuromuscular Disease Group specialised trials register (September 2002), MEDLINE (January 1966 to November 2002) and EMBASE (January 1980 to November 2002). We checked the bibliographies in reports of the randomised trials and contacted authors to identify additional published or unpublished data.

SELECTION CRITERIA

Types of studies: all randomised or quasi-randomised trials.

TYPES OF PARTICIPANTS

all adults and children with a diagnosis of Lambert-Eaton myasthenic syndrome, with or without small-cell lung cancer. Types of interventions: any form of medical (pharmacological or physical) treatment. Types of outcome measures: Primary: change in the muscle strength scale score (Quantitative Myasthenia Gravis score), or limb muscle strength measured by myometry. Secondary: improvement in the mean amplitude of the resting compound muscle action potentials. The mean amplitude used was the mean of all muscles tested.

DATA COLLECTION AND ANALYSIS

We identified three randomised controlled trials. Individual patient data were only available for one trial.

MAIN RESULTS

The three eligible trials included two controlled trials of the effects of 3,4-diaminopyridine compared with placebo in a total of 38 patients with Lambert-Eaton myasthenic syndrome, one of which was of crossover design. A third crossover trial compared intravenous immunoglobulin treatment to placebo in nine patients with Lambert-Eaton myasthenic syndrome. A meta-analysis of the primary endpoint results of these trials was not possible because of differences in comparisons and endpoints and, in two trials, lack of individual patient data. EFFECTS OF 3,4-DIAMINOPYRIDINE: Two trials of 3,4-diaminopyridine reported a significant improvement in the primary endpoint of muscle strength score, or myometric limb measurement following treatment. Both trials also reported a significant improvement in the secondary endpoint of resting compound muscle action potential amplitude following 3,4-diaminopyridine, compared with placebo. A meta-analysis of the primary endpoint results was not possible because of marked differences in these two trials regarding primary outcome measures. However, a meta-analysis of the secondary endpoint (improvement in the amplitude of the mean resting compound muscle action potential) was possible. It was necessary to assume a known correlation (similarity) of the paired responses for each individual in the two treatment periods in order to properly allow for the crossover design of one of the two trials (the correlation coefficient was assumed to be 0.5 in calculations). Using this approach, meta-analysis revealed a significant overall benefit in compound muscle action potential amplitude after 3,4-diaminopyridine treatment. The overall weighted mean difference was 1.80 mV (95% confidence interval 0.82 to 2.78), favouring treatment. These results were not sensitive to the assumption made because the overall benefit estimated was still significant when the correlation was assumed to be less than 0.1. EFFECTS OF INTRAVENOUS IMMUNOGLOBULIN: A crossover trial reported a significant improvement in the primary outcome measure of myometric limb strength when patients received intravenous immunoglobulin compared to placebo infusions. This trial also demonstrated an improvement in the secondary outcome measure of change in the mean resting compound muscle action potential amplitude following intravenous immunoglobulin, but this improvement did not reach significance. Clinical improvement lasted for up to eight weeks.

REVIEWER'S CONCLUSIONS

Limited evidence from randomised controlled trials showed that either 3,4-diaminopyridine or intravenous immunoglobulin improved muscle strength scores and compound muscle action potential amplitudes in patients with Lambert-Eaton myasthenic syndrome. There are insufficient data at present to quantify this treatment effect. Other possible treatments, such as plasma exchange, steroids and immunosuppressive agents have not been tested in randomised controlled trials.

Intravenous immunoglobulin in neurological disease: a specialist review

Treatment of neurological disorders with intravenous immunoglobulin (IVIg) is an increasing feature of our practice for an expanding range of indications. For some there is evidence of benefit from randomised controlled trials, whereas for others evidence is anecdotal. The relative rarity of some of the disorders means that good randomised control trials will be difficult to deliver. Meanwhile, the treatment is costly and pressure to "do something" in often distressing disorders considerable. This review follows a 1 day meeting of the authors in November 2000 and examines current evidence for the use of IVIg in neurological conditions and comments on mechanisms of action, delivery, safety and tolerability, and health economic issues. Evidence of efficacy has been classified into levels for healthcare interventions (tables 1 and 2).

Paraneoplastic syndromes associated with bronchogenic carcinoma

Paraneoplastic syndromes associated with lung cancer are diverse in their presentation, pathophysiology, and implications. They can be seen as a diagnostic and therapeutic challenge or as an opportunity to detect an otherwise asymptomatic malignancy. Unraveling the mechanisms that produce these syndromes will lead to insight into tumor biology that will be translated into novel approaches for early detection and therapy.

Lambert-Eaton myasthenic syndrome

The Lambert-Eaton myasthenic syndrome is a neuromuscular disorder characterised by defective neurotransmitter release at autonomic neurones and presynaptic terminals of the neuromuscular junction. It is caused by an IgG autoantibody formed against especially the P/Q type of voltage-gated calcium channels (VGCC) which is an essential component of the mechanism of neurotransmitter release. Many patients have an associated small cell carcinoma of the lung which appears to provide the antigenic stimulus for antibody production, although there is another group with no underlying malignancy. Both groups show an association with immunological disorders. Assay of VGCC antibody titres and electrophysiological tests help to differentiate Lambert-Eaton myasthenic syndrome from other disorders of the neuromuscular junction. Several drugs and therapeutic interventions capable of producing significant clinical improvement are currently available. Patients should also be investigated for underlying tumours, the specific treatment of which can result in remission or amelioration of symptoms.

Lambert-Eaton myasthenic syndrome. Report of two cases

Two cases of Lambert-Eaton myasthenic syndrome, in female patients whose neoplasm investigation was negative, are reported. Repetitive stimulation of ulnar nerve showed an incremental response (+187% and +198%). Needle EMG was normal in one of them, however, the other patient showed fibrillation potentials, positive sharp waves, potentials of low amplitude and short duration. The authors discuss the clinical, electrophysiological, and pathological features of the disease, as well as some aspects of the treatment and follow-up of these patients.

Long-term follow-up of Lambert-Eaton syndrome treated with intravenous immunoglobulin

Recent reports have shown that patients with Lambert-Eaton myasthenic syndrome (LEMS) improve transiently after high-dose intravenous immunoglobulin (IVIG) administration. Information about the usefulness of IVIG for long-term treatment is rather scanty. Our findings demonstrate the efficacy of monthly IVIG courses at a dose of 0.4 g/kg/day for 5 days, in a 41-year-old patient with LEMS without detectable malignancy. Improvement in limb strength, peak expiratory flow rate, and electrophysiological parameters, as well as clinical signs following IVIG, was evident as early as 7 days after the first course and is still maintained at 24-months follow-up.

Intravenous immunoglobulin treatment in paraneoplastic neurological syndromes with antineuronal autoantibodies

OBJECTIVE

To evaluate the effect of intravenous high dose human immunoglobulin (IVIg) therapy on the clinical course and autoantibody titres of patients with neurological paraneoplastic syndromes.

METHODS

Twenty two patients with paraneoplastic encephalomyelitis and sensory neuronopathy syndrome associated with anti-Hu antibodies (18) or paraneoplastic cerebellar degeneration (PCD) with anti-Yo antibodies (four), were treated with 1-26 (mean 5.8) cycles of IVIg. The Rankin scale was used to evaluate the response.

RESULTS

The only serious toxicity was one case of haemolytic anaemia. Twenty one patients were evaluable for therapeutic response. One patient, with subacute sensory neuronopathy (SSN), improved for at least 15 months, 10 remained stable (eight with anti-Hu and two with anti-Yo antibodies), and 10 deteriorated (eight with anti-Hu and two with anti-Yo antibodies). In seven of the 10 patients who stabilised, the syndrome had already made a plateau when the treatment was started but three patients (one with anti-Hu and two with anti-Yo antibodies) who had still been progressing stabilised for six, eight, and more than 48 months, including one patient with SSN who achieved stabilisation when the neurological dysfunction was only moderate (Rankin scale = 3). Another patient with SSN and initial stable response worsened when IVIg was reduced and improved when it was increased. No significant predictive factors of outcome could be identified but improvement or stabilisation was more frequent in patients with isolated involvement of the peripheral nervous system (62%) than in patients with evidence of CNS damage (37%) at the onset of treatment. Stabilisation in patients with CNS involvement was only achieved when the neurological dysfunction was already severe (Rankin scale > 3). The titres of autoantibodies did not change significantly.

CONCLUSION

Treatment with IVIg at the doses given in the present protocol was not effective in paraneoplastic CNS syndromes associated with antineuronal antibodies. The role of this regime in the treatment of SSN should be further evaluated.

Trial to establish an animal model of paraneoplastic cerebellar degeneration with anti-Yo antibody. 1. Mouse strains bearing different MHC molecules produce antibodies on immunization with recombinant Yo protein, but do not cause Purkinje cell loss

Passive transfer of anti-Yo antibody from patients with paraneoplastic cerebellar degeneration (PCD) associated with gynecological or breast carcinoma has not been successful in inducing an animal model. We used active immunization with recombinant Yo protein of four strains of mice bearing different MHC molecules: BALB/c (H-2d), C3H (H-2k), C57BL/6 (H-2b), SJL/J (H-2s). All the strains produced high anti-Yo antibody titer but none developed cerebellar ataxia or showed Purkinje cell loss. Spleen cells from the immunized mice also reacted with recombinant protein. Because C57BL/6(nu/nu) mice produce no anti-Yo antibody, mature helper T cells are required for its production. Results suggest that antibody production in peripheral blood alone is not sufficient for the development of PCD and that MHC class II molecules function in the activation of T cells to help B cells to help B cells produce antibodies.