Guillain-Barré syndrome: multifactorial mechanisms versus defined subgroups

Peripheral neuropathy and gastroenterologic disorders: an overview on an underrecognized association

BACKGROUND AND AIM OF THE WORK

Although peripheral neuropathies in children are often of genetic origin, acquired causes should be carefully looked for and ruled out also in the pediatric age. Gastroenterological disorders can be complicated by peripheral neuropathy as a result of micronutrients deficiency, drug toxicity or because of shared pathophysiological mechanisms.

METHODS

In this descriptive review we sought to give an overview on the most relevant clinical conditions in which peripheral neuropathies are associated with gastro-intestinal disorders or symptoms.

RESULTS

We describe the clinical, demographic, and electrophysiological features of peripheral neuropathy in three main clinical scenarios: in the context of common gastroenterological disorders (inflammatory bowel and celiac disease), in the context of micronutrients deficiencies arising from malabsorption irrespective of etiology, and in a rare degenerative mitochondrial disorder, mitochondrial neurogastrointestinal encephalomyopathy (MNGIE) disorder.

CONCLUSIONS

The association between gastrointestinal and peripheral nervous system symptoms is probably still underrecognized but has to be actively sought, in order to provide prompt diagnosis resulting in optimal care and long-term management with the aim to improve quality of life and, at least in some conditions, try to impact on prognosis.

Spectrum of Guillain-Barré syndrome in tertiary care hospital at Kolkata

Objective:

In childhood Guillain–Barré syndrome (GBS), the clinical profiles using intravenous immunoglobulin (IVIg) in addition to supportive care were studied.

Materials and Methods:

This was a retrospective analysis of 139 children with severe GBS admitted to our respiratory care unit managed with the IVIg as an adjunct intervention to conventional supportive and respiratory care.

Results:

In our case series of 139 cases, motor weakness was the most common presenting feature. Antecedent illness was found in 66.7% of cases in the preceding two weeks, which included nonspecific illness, acute respiratory infection, diarrhea, and chickenpox. At onset, sensory symptoms (pain and paresthesia) were noted in 59% of the cases and limb weakness in 77%. On admission, a majority (61.54%) were in Hughes neurological disability grading stage V; all had limb weakness at the peak deficit, autonomic disturbance was seen in 35.8%, and bulbar palsy in 52%. Duration of illness was less than three weeks in 67% of cases. The mean duration of ventilation was 21.5 days (range, 5-60 days).

Conclusions:

Male preponderance and motor weakness was the most common presenting illness and a majority achieved full recovery in our series. Although IVIg may be useful in the treatment of GBS, the key issue is excellent intensive care unit management.

What is different about serotype 1 pneumococci?

Serotype 1 Streptococcus pneumoniae is among the most commonly isolated serotype in invasive pneumococcal disease but is rarely found causing asymptomatic nasopharyngeal colonization. Compared to infection by other serotypes, infection caused by serotype 1 is more likely to be identified in young patients without comorbidities but is generally associated with a lower mortality. Empyema and extrapulmonary manifestations are common. Outbreaks of serotype 1 disease have been reported in closed communities and epidemics are particularly common in sub-Saharan Africa. The serotype 1 capsular polysaccharide is a zwitterionic structure that enables it to function as a T-cell dependent antigen under some circumstances, in contrast to other pneumococcal capsular polysaccharides that are T-cell independent antigens. There are also differences in the key virulence factor pneumolysin in some serotype 1 isolates. The clinical significance of these differences remains to be determined.

Improving therapeutic strategies for secondary bacterial pneumonia following influenza

Secondary bacterial pneumonia following influenza is an old problem, which is re-emerging. Despite rapid advances in our armamentarium of antimicrobials, the case-fatality rate for this frequent complication of influenza remains high. In some settings, common treatment options may actually contribute to poor outcomes, as rapid lysis of pathogenic bacteria on the backdrop of an activated immune system responding to influenza may lead to inflammatory damage in the lung. An understanding of the inter-related contributions of the antecedent viral infection, the invading bacteria and the host immune response is necessary to formulate an appropriate therapeutic approach. Prevention and resolution of these fulminant infections will require new approaches, including alternate treatment strategies, combination therapies targeting several aspects of the pathogenic process and, potentially, immunomodulation. In the not-so-distant future, strategies aimed at disarming pathogens without eliminating them may be more effective than our current treatment paradigms.

Comparative genomic analysis of clinical strains of Campylobacter jejuni from South Africa

BACKGROUND

Campylobacter jejuni is a common cause of acute gastroenteritis and is also associated with the post-infectious neuropathies, Guillain-Barré and Miller Fisher syndromes. In the Cape Town area of South Africa, C. jejuni strains with Penner heat-stable (HS) serotype HS:41 have been observed to be overrepresented among cases of Guillain-Barré syndrome. The present study examined the genetic content of a collection of 32 South African C. jejuni strains with different serotypes, including 13 HS:41 strains, that were recovered from patients with enteritis, Guillain-Barré or Miller Fisher syndromes. The sequence-based typing methods, multilocus sequence typing and DNA microarrays, were employed to potentially identify distinguishing features within the genomes of these C. jejuni strains with various disease outcomes.

METHODOLOGY/PRINCIPAL FINDINGS

Comparative genomic analyses demonstrated that the HS:41 South African strains were clearly distinct from the other South African strains. Further DNA microarray analysis demonstrated that the HS:41 strains from South African patients with the Guillain-Barré syndrome or enteritis were highly similar in gene content. Interestingly, the South African HS:41 strains were distinct in gene content when compared to HS:41 strains from other geographical locations due to the presence of genomic islands, referred to as Campylobacter jejuni integrated elements (CJIEs). Only the integrated element CJIE1, a Campylobacter Mu-like prophage, was present in the South African HS:41 strains whereas this element was absent in two closely-related HS:41 strains from Mexico. A more distantly-related HS:41 strain from Canada possessed both integrated elements CJIE1 and CJIE2.

CONCLUSION/SIGNIFICANCE

These findings demonstrate that CJIEs may contribute to the differentiation of closely-related C. jejuni strains. In addition, the presence of bacteriophage-related genes in CJIE1 may contribute to the genomic diversity of C. jejuni strains. This comparative genomic analysis of C. jejuni provides fundamental information that potentially could lead to improved methods for analyzing the epidemiology of disease outbreaks.

Identification of DNA sequence variation in Campylobacter jejuni strains associated with the Guillain-Barré syndrome by high-throughput AFLP analysis

BACKGROUND

Campylobacter jejuni is the predominant cause of antecedent infection in post-infectious neuropathies such as the Guillain-Barré (GBS) and Miller Fisher syndromes (MFS). GBS and MFS are probably induced by molecular mimicry between human gangliosides and bacterial lipo-oligosaccharides (LOS). This study describes a new C. jejuni-specific high-throughput AFLP (htAFLP) approach for detection and identification of DNA polymorphism, in general, and of putative GBS/MFS-markers, in particular.

RESULTS

We compared 6 different isolates of the "genome strain" NCTC 11168 obtained from different laboratories. HtAFLP analysis generated approximately 3000 markers per stain, 19 of which were polymorphic. The DNA polymorphisms could not be confirmed by PCR-RFLP analysis, suggesting a baseline level of 0.6% AFLP artefacts. Comparison of NCTC 11168 with 4 GBS-associated strains revealed 23 potentially GBS-specific markers, 17 of which were identified by DNA sequencing. A collection of 27 GBS/MFS-associated and 17 enteritis control strains was analyzed with PCR-RFLP tests based on 11 of these markers. We identified 3 markers, located in the LOS biosynthesis genes cj1136, cj1138 and cj1139c, that were significantly associated with GBS (P = 0.024, P = 0.047 and P < 0.001, respectively). HtAFLP analysis of 13 highly clonal South African GBS/MFS-associated and enteritis control strains did not reveal GBS-specific markers.

CONCLUSION

This study shows that bacterial GBS markers are limited in number and located in the LOS biosynthesis genes, which corroborates the current consensus that LOS mimicry may be the prime etiologic determinant of GBS. Furthermore, our results demonstrate that htAFLP, with its high reproducibility and resolution, is an effective technique for the detection and subsequent identification of putative bacterial disease markers.

Guillain-Barré syndrome in the elderly: clinical, electrophysiological, therapeutic and outcome features

There are few papers devoted to geriatric Guillain-Barré (GBS) and many related issues remain unanswered. OBJECTIVE: To describe clinical, electrophysiological and therapeutic features in this age. METHOD: Clinico-epidemiological data and therapy of GBS patients older than 60 years were reviewed. Hughes scores were used to quantify neurological deficit and define outcome. RESULTS: Among 18 patients (mean age 64.8 years), 9 had evident prodrome and 80% noticed initially sensory-motor deficit. Demyelinating GBS was found in 8 and axonal in 6 subjects. There was one Miller-Fisher and 3 unclassified cases. Plasmapheresis (PFX) was single therapy in 12 patients and intravenous immunoglobulin (IVIg) in 2. Disability scores just before therapy were similar in both groups, so as short and long term outcome. CONCLUSION: Axonal GBS seems to be more frequent in the elderly and this may have prognostic implications. PFX and IVIg were suitable options, but complications were noticed with PFX. Prospective studies are needed to better understand and manage GBS in the elderly.

Beyond neurons: evidence that immune and glial cells contribute to pathological pain states

Chronic pain can occur after peripheral nerve injury, infection, or inflammation. Under such neuropathic pain conditions, sensory processing in the affected body region becomes grossly abnormal. Despite decades of research, currently available drugs largely fail to control such pain. This review explores the possibility that the reason for this failure lies in the fact that such drugs were designed to target neurons rather than immune or glial cells. It describes how immune cells are a natural and inextricable part of skin, peripheral nerves, dorsal root ganglia, and spinal cord. It then examines how immune and glial activation may participate in the etiology and symptomatology of diverse pathological pain states in both humans and laboratory animals. Of the variety of substances released by activated immune and glial cells, proinflammatory cytokines (tumor necrosis factor, interleukin-1, interleukin-6) appear to be of special importance in the creation of peripheral nerve and neuronal hyperexcitability. Although this review focuses on immune modulation of pain, the implications are pervasive. Indeed, all nerves and neurons regardless of modality or function are likely affected by immune and glial activation in the ways described for pain.

Neurologic manifestations of gastrointestinal disease

Although previously considered rare, neurologic manifestations of gastrointestinal diseases are increasingly recognized. Understanding of Whipple disease and gluten sensitivity is in transition and these conditions are becoming the province of neurologists. Recent improvements in diagnostic testing have improved our understanding and case finding for vitamin B12 deficiency. Many patients with these conditions present with neurologic manifestations alone. Therefore, these conditions are becoming the province of neurologists, and neurologic manifestations of gastrointestinal disease are becoming a more common part of neurologic practice.

Transcranial magnetic stimulation studies in the Miller Fisher syndrome: evidence of corticospinal tract abnormality

OBJECTIVES

To evaluate serial central motor conduction time in the Miller Fisher syndrome.

METHOD

Three patients with classic Miller Fisher syndrome were evaluated clinically. They had serial central motor conduction times measured with transcranial magnetic stimulation and nerve conduction studies. Motor evoked potentials were recorded from the first dorsal interossei and abductor hallucis muscles.

RESULTS

All three patients showed reduction in central motor conduction times in tandem with gradual clinical improvement at each review.

CONCLUSIONS

There is electrophysiological evidence of a central reversible corticospinal tract conduction abnormality in the Miller Fisher syndrome.

Antecedent symptoms in Guillain-Barré syndrome: an important indicator for clinical and serological subgroups

OBJECTIVES

To examine whether Guillain-Barré syndrome (GBS) can be classified in clinical and immunological subgroups based on the type of prior illness. Background - The existence of antecedent symptoms supports the diagnosis of GBS in patients who experience acute muscle weakness progression. However, little is known about additional meanings of determining antecedent symptoms.

MATERIALS AND METHODS

Prospective investigation of prior infectious illness in GBS and related disorders (n=176).

RESULTS

The frequent antecedent symptoms in GBS and related disorders were fever (52%), cough (48%), sore throat (39%), nasal discharge (30%), and diarrhea (27%). Patients who had sore throats or coughs frequently had ophthalmoparesis (respectively P=0.0004, P=0.001) and IgG anti-GQ1b antibody (P=0.01, P=0.007). Fever was associated with bulbar palsy (P=0.047) and headache with facial palsy (P=0.04). Patients with diarrhea often had anti-ganglioside IgG (anti-GM1 [P=0.0006] and anti-GM1b [P=0.008]), IgM (anti-GM1 [P=0.03], anti-GM1b [P=0.02], and anti-GalNAc-GD1a [P=0.047]) antibodies and rarely showed ophthalmoparesis or bulbar palsy (respectively P=0.02, P=0.04). Diarrhea and abdominal pain were closely associated with Campylobacter jejuni serology (respectively P<0.0001, P=0.01), whereas other symptoms were not related to pathogens such as cytomegalovirus, Epstein-Barr virus, or Mycoplasma pneumoniae.

CONCLUSIONS

Our comprehensive study showed that GBS preceded by sore throat, cough, fever, headache, or diarrhea respectively forms clinical or serological subgroups, or both. This association is not necessarily dependent on infection by the known trigger pathogens.

Recent advances of therapeutic apheresis in Guillain-Barré syndrome

Acute idiopathic demyelinating polyneuritis (AIDP), commonly known as the Guillain-Barré syndrome (GBS), is an immune-mediated demyelinating disease of the peripheral nerve and nerve roots. A number of immunological mechanisms were described, but the exact pathomechanism has not been explained fully. Presumably, a variety of immunological processes lead to a relatively uniform clinical phenotype. Two large multicenter studies showed that plasma exchange (PE) was significantly superior to supportive treatment only. Selective adsorption (SA) also was employed as a method of therapeutic apheresis, and various smaller studies established that both PE and SA are equally effective treatments for GBS. Recently, it was demonstrated that the number of apheresis treatments should be adapted to the severity of disease. A large multicenter controlled study established equal efficacy of PE and intravenous immunoglobulin treatment (IVIg) as well as the combination of PE and IVIg. Since that time, the use of apheresis for the treatment of GBS declined in many countries due to the easier application of IVIg. The number of patients treated in larger hospitals with long-standing experience in the treatment of GBS also has declined.

I.v. immunoglobulin reduces circulating proinflammatory cytokines in Guillain-Barré syndrome

BACKGROUND

Treatment with human i.v. immunoglobulin (IVIg) modifies the course of Guillain-Barré syndrome (GBS), but its specific mode of action is unknown. Cellular interactions mediated through the release of cytokines play a role in the pathogenesis of GBS and may be regulated by IVIg therapy.

OBJECTIVE

To delineate possible immunoregulatory mechanisms of IVIg in patients with GBS.

METHODS

Circulating levels of the proinflammatory cytokines, tumor necrosis factor (TNF)-alpha and interleukin (IL)-1beta, were assayed in 21 patients with GBS before and serially after IVIg therapy. Comparisons were made with serum concentration of the anti-inflammatory cytokines, soluble TNF-alpha receptor and IL-10. Serial measurements were also performed in 12 untreated patients with relatively mild disease and 7 patients treated by plasma exchange.

RESULTS

Circulating levels of TNF-alpha and IL-1beta decreased after treatment with IVIg but remained relatively high in untreated patients and in those treated by plasma exchange. Clinical improvement in patients treated with IVIg was associated with a reduction in unbound TNF-alpha during the acute phase of the illness. Circulating levels of anti-inflammatory cytokines were not affected by IVIg treatment.

CONCLUSION

Data presented here suggest a novel mechanism of action of IVIg that involves selective modulation of circulating proinflammatory cytokines.

Demyelinating inflammatory neuropathies, including Guillain-Barré syndrome

The highly complex and multiple mechanisms responsible for the development of demyelinating neuropathies are reviewed, in particular Guillain-Barré syndrome and its variant Miller Fisher syndrome, chronic inflammatory demyelinating neuropathy, multifocal motor neuropathy, anti-myelin-associated glycoprotein neuropathy, as well as experimental models. Recent investigations into the role of auto antibodies against myelin proteins, or glycolipids have given insights into the pathogenesis of demyelinating inflammatory neuropathies.