Pieter A. van Doorn

Clinical features, pathogenesis, and treatment of Guillain-Barré syndrome

Guillain-Barré syndrome (GBS) is an important cause of acute neuromuscular paralysis. Molecular mimicry and a cross-reactive immune response play a crucial part in its pathogenesis, at least in those cases with a preceding Campylobacter jejuni infection and with antibodies to gangliosides. The type of preceding infection and patient-related host factors seem to determine the form and severity of the disease. Intravenous immunoglobulin (IVIg) and plasma exchange are effective treatments in GBS; mainly for practical reasons, IVIg is the preferred treatment. Whether mildly affected patients or patients with Miller Fisher syndrome also benefit from IVIg is unclear. Despite medical treatment, GBS often remains a severe disease; 3-10% of patients die and 20% are still unable to walk after 6 months. In addition, many patients have pain and fatigue that can persist for months or years. Advances in prognostic modelling have resulted in the development of a new and simple prognostic outcome scale that might also help to guide new treatment options, particularly in patients with GBS who have a poor prognosis.

Intravenous immune globulin (10% caprylate-chromatography purified) for the treatment of chronic inflammatory demyelinating polyradiculoneuropathy (ICE study): a randomised placebo-controlled trial

BACKGROUND Short-term studies suggest that intravenous immunoglobulin might reduce disability caused by chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) but long-term effects have not been shown. We aimed to establish whether 10% caprylate-chromatography purified immune globulin intravenous (IGIV-C) has short-term and long-term benefit in patients with CIDP. METHODS 117 patients with CIDP who met specific neurophysiological inflammatory neuropathy cause and treatment (INCAT) criteria participated in a randomised, double-blind, placebo-controlled, response-conditional crossover trial. IGIV-C (Gamunex) or placebo was given every 3 weeks for up to 24 weeks in an initial treatment period, and patients who did not show an improvement in INCAT disability score of 1 point or more received the alternate treatment in a crossover period. The primary outcome was the percentage of patients who had maintained an improvement from baseline in adjusted INCAT disability score of 1 point or more through to week 24. Patients who showed an improvement and completed 24 weeks of treatment were eligible to be randomly re-assigned in a blinded 24-week extension phase. Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00220740. FINDINGS During the first period, 32 of 59 (54%) patients treated with IGIV-C and 12 of 58 (21%) patients who received placebo had an improvement in adjusted INCAT disability score that was maintained through to week 24 (treatment difference 33.5%, 95% CI 15.4-51.7; p=0.0002). Improvements from baseline to endpoint were also recorded for grip strength in the dominant hand (treatment difference 10.9 kPa, 4.6-17.2; p=0.0008) and the non-dominant hand (8.6 kPa, 2.6-14.6; p=0.005). Results were similar during the crossover period. During the extension phase, participants who continued to receive IGIV-C had a longer time to relapse than did patients treated with placebo (p=0.011). The incidence of serious adverse events per infusion was 0.8% (9/1096) with IGIV-C versus 1.9% (11/575) with placebo. The most common adverse events with IGIV-C were headache, pyrexia, and hypertension. INTERPRETATION This study, the largest reported trial of any CIDP treatment, shows the short-term and long-term efficacy and safety of IGIV-C and supports use of IGIV-C as a therapy for CIDP.

European Federation of Neurological Societies/Peripheral Nerve Society Guideline on management of chronic inflammatory demyelinating polyradiculoneuropathy: Report of a joint task force of the European Federation of Neurological Societies and the Peripheral Nerve Society - First Revision

Background: Consensus guidelines on the definition, investigation, and treatment of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) have been published (J Peripher Nerv Syst 2005; 10: 220–228, Eur J Neurol 2006; 13: 326–332). Objectives: To revise these guidelines. Methods: Disease experts, including a representative of patients, considered references retrieved from MEDLINE and Cochrane Systematic Reviews published between August 2004 and July 2009 and prepared statements that were agreed in an iterative fashion.

Guillain-Barré syndrome: pathogenesis, diagnosis, treatment and prognosis.

Guillain–Barré syndrome (GBS) is a potentially life-threatening postinfectious disease characterized by rapidly progressive, symmetrical weakness of the extremities. About 25% of patients develop respiratory insufficiency and many show signs of autonomic dysfunction. Diagnosis can usually be made on clinical grounds, but lumbar puncture and electrophysiological studies can help to substantiate the diagnosis and to differentiate demyelinating from axonal subtypes of GBS. Molecular mimicry of pathogen-borne antigens, leading to generation of crossreactive antibodies that also target gangliosides, is part of the pathogenesis of GBS; the subtype and severity of the syndrome are partly determined by the nature of the antecedent infection and specificity of such antibodies. Intravenous immunoglobulin and plasma exchange are proven effective treatments but many patients have considerable residual deficits. Discrimination of patients with treatment-related fluctuations from those with acute-onset chronic inflammatory demyelinating polyneuropathy is important, as these conditions may require different treatments. Novel prognostic models can accurately predict outcome and the need for artificial ventilation, which could aid the selection of patients with a poor prognosis for more-individualized care. This Review summarizes the clinical features of and diagnostic criteria for GBS, and discusses its pathogenesis, treatment and prognosis.

Enzyme replacement therapy in late-onset Pompe's disease : A three-year follow-up

Pompes disease is an autosomal recessive myopathy. The characteristic lysosomal storage of glycogen is caused by acid α‐glucosidase deficiency. Patients with late‐onset Pompes disease present with progressive muscle weakness also affecting pulmonary function. In search of a treatment, we investigated the feasibility of enzyme replacement therapy with recombinant human α‐glucosidase from rabbit milk. Three patients (aged 11, 16, and 32 years) were enrolled in the study. They were all wheelchair‐bound and two of them were ventilator dependent with a history of deteriorating pulmonary function. After 3 years of treatment with weekly infusions of α‐glucosidase, the patients had stabilized pulmonary function and reported less fatigue. The youngest and least affected patient showed an impressive improvement of skeletal muscle strength and function. After 72 weeks of treatment, he could walk without support and finally abandoned his wheelchair. Our findings demonstrate that recombinant human α‐glucosidase from rabbit milk has a therapeutic effect in late‐onset Pompes disease. There is good reason to continue the development of enzyme replacement therapy for Pompes disease and to explore further the production of human therapeutic proteins in the milk of mammals. Ann Neurol 2004;55:000–000

Guillain-Barré syndrome

Guillain-Barré syndrome is the most common and most severe acute paralytic neuropathy, with about 100,000 people developing the disorder every year worldwide. Under the umbrella term of Guillain-Barré syndrome are several recognisable variants with distinct clinical and pathological features. The severe, generalised manifestation of Guillain-Barré syndrome with respiratory failure affects 20-30% of cases. Treatment with intravenous immunoglobulin or plasma exchange is the optimal management approach, alongside supportive care. Understanding of the infectious triggers and immunological and pathological mechanisms has advanced substantially in the past 10 years, and is guiding clinical trials investigating new treatments. Investigators of large, worldwide, collaborative studies of the spectrum of Guillain-Barré syndrome are accruing data for clinical and biological databases to inform the development of outcome predictors and disease biomarkers. Such studies are transforming the clinical and scientific landscape of acute autoimmune neuropathies.

A clinical prognostic scoring system for Guillain-Barré syndrome.

BACKGROUND Guillain-Barré syndrome (GBS) is an acute post-infectious immune-mediated peripheral neuropathy with a highly variable clinical course and outcome. We aimed to develop and validate a scoring system based on clinical characteristics in the acute phase of GBS to predict outcome at 6 months. METHODS We studied patients with GBS who were unable to walk independently. A derivation set included 388 patients from two randomised controlled trials and one pilot study. Potential predictors were assessed for their association with the inability to walk independently at 6 months. A simple clinical scoring system was developed on the basis of regression coefficients of predictors in a multivariable logistic regression model. Model performance was quantified with respect to discrimination (area under receiver operating characteristics curve, AUC) and calibration (graphically). We validated our scoring system in a set of 374 patients from another randomised trial. FINDINGS We included three variables that were predictive of poor outcome at 6 months in our model: age, preceding diarrhoea, and GBS disability score at 2 weeks after entry. Scores ranged from 1 to 7, with three categories for age, two for diarrhoea, and five for GBS disability score at 2 weeks. Predictions corresponding to these prognostic scores ranged from 1% to 83% for the inability to walk independently at 6 months. Predictions agreed well with observed outcome frequencies (adequate calibration) and showed a very good discriminative ability (AUC 0.85) in both data sets. INTERPRETATION A simple scoring system for patients with GBS, based on three clinical characteristics, accurately predicts outcome at 6 months. The system could be used to counsel individual patients and identify high-risk groups to guide future trials.

Diagnosis of Guillain-Barre syndrome and validation of Brighton criteria

Guillain-Barré syndrome is an acute polyradiculoneuropathy with a variable clinical presentation. Accurate diagnostic criteria are essential for patient care and research, including clinical trials and vaccine safety studies. Several diagnostic criteria for Guillain-Barré syndrome have been proposed, including the recent set by the Brighton Collaboration. In the present study we describe in detail the key diagnostic features required to meet these Brighton criteria in a study population of 494 adult patients with Guillain-Barré syndrome, previously included in therapeutic and observational studies. The patients had a median age of 53 years (interquartile range 36-66 years) and males slightly predominated (56%). All patients developed bilateral limb weakness which generally involved both upper and lower extremities. The weakness remained restricted to the legs in 6% and to the arms in 1% of the patients. Decreased reflexes in paretic arms or legs were found initially in 91% of patients and in all patients during follow-up. Ten (2%) patients however showed persistence of normal reflexes in paretic arms. Disease nadir was reached within 2 weeks in 80%, within 4 weeks in 97% and within 6 weeks in all patients. A monophasic disease course occurred in 95% of patients, of whom 10% had a treatment-related fluctuation. A clinical deterioration after 8 weeks of onset of weakness occurred in 23 (5%) patients. Cerebrospinal fluid was examined in 474 (96%) patients. A mild pleocytosis (5 to 50 cells/μl) was found in 15%, and none had more than 50 cells/μl. An increased cerebrospinal fluid protein concentration was found only in 64% of patients, highly dependent on the timing of the lumbar puncture after onset of weakness (49% at the first day to 88% after 2 weeks). Nerve electrophysiology was compatible with the presence of a neuropathy in 99% of patients, but only 59% fulfilled the current criteria for a distinct subtype of Guillain-Barré syndrome. Patients with a complete data set (335) were classified according to the Brighton criteria, ranging from a high to a low level of diagnostic certainty, as level 1 in 61%, level 2 in 33%, level 3 in none, and level 4 in 6% of patients. Patients categorized in these levels did not differ with respect to proportion of patients with preceding events, initial clinical manifestations or outcome. The observed variability in the key diagnostic features of Guillain-Barré syndrome in the current cohort study, can be used to improve the sensitivity of the diagnostic criteria.

European Federation of Neurological Societies/Peripheral Nerve Society Guideline* on management of chronic inflammatory demyelinating polyradiculoneuropathy. Report of a joint task force of the European Federation of Neurological Societies and the Peripheral Nerve Society

Abstract  Background: Numerous sets of diagnostic criteria have sought to define chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), and randomized trials and systematic reviews of treatment have been published. Objectives: The aim of this guideline was to prepare consensus guidelines on the definition, investigation, and treatment of CIDP. Methods: Disease experts and a representative of patients considered references retrieved from MEDLINE and Cochrane Systematic Reviews in May 2004 and prepared statements that were agreed in an iterative fashion. Recommendations: The Task Force agreed on good practice points to define clinical and electrophysiological diagnostic criteria for CIDP with or without concomitant diseases and investigations to be considered. The principal treatment recommendations were as follows: (1) intravenous immunoglobulin (IVIg) or corticosteroids should be considered in sensory and motor CIDP (level B recommendation); (2) IVIg should be considered as the initial treatment in pure motor CIDP (good practice point); (3) if IVIg and corticosteroids are ineffective, plasma exchange should be considered (level A recommendation); (4) if the response is inadequate or the maintenance doses of the initial treatment are high, combination treatments or adding an immunosuppressant or immunomodulatory drug should be considered (good practice point); and (5) symptomatic treatment and multidisciplinary management should be considered (good practice point).

Pharmacokinetics of intravenous immunoglobulin and outcome in Guillain-Barré syndrome.

Intravenous immunoglobulin (IVIg) is the first choice treatment for Guillain‐Barré syndrome (GBS). All patients initially receive the same arbitrary dose of 2g per kg body weight. Not all patients, however, show a good recovery after this standard dose. IVIg clearance may depend on disease severity and vary between individuals, implying that this dose is suboptimal for some patients. In this study, we determined whether the pharmacokinetics of IVIg is related to outcome in GBS.