Acute immune polyneuropathies: correlations of serum antibodies to Campylobacter jejuni and Helicobacter pylori with anti-GM1 antibodies and clinical patterns of disease

Acute myelitis of children with positive anti-GM1 antibody: Case series and literature review

RATIONALE

To explore the clinical features, treatment, and prognosis of acute myelitis (AM) of children with positive blood anti- ganglioside (GM1) antibodies.

PATIENT CONCERNS

Two cases of AM of children with positive anti-GM1 antibody were retrospectively collected and followed up for 6 months. Two cases had positive helicobacter pylori IgG antibody, and Case 2 also had positive mycoplasma IgM antibody.

DIAGNOSES

Two cases had typical symptoms of myelitis, abnormal spinal magnetic resonance imaging (MRI), and positive serum anti-GM1 IgM.

INTERVENTIONS

They were treated with steroid, immunoglobulin and rehabilitation.

OUTCOMES

Symptoms of AM were relieved after treatment. After 6 months of follow-up, case 1 was fully recovered and case 2 was partially recovered. Summarizing previous reports in literature and our 2 cases, AM with positive anti-GM1 antibody can be induced by multiple pathogen infections. About 35.7% were fully recovered, 42.9% had mild sequelae, and 21.4% had severe sequelae.

LESSONS

Post-infection immune injury plays an important role in the pathogenesis of AM with positive anti-GM1 antibody. H pylori and Mycoplasma pneumoniae infection may also induce AM with positive anti-GM1 antibody. Screening and treatment of pathogens were required and only 21.4% patients had severe sequelae after treatment.

Childhood acute and chronic immune-mediated polyradiculoneuropathies

Immune-mediated polyradiculoneuropathies are divided into Guillain-Barré syndrome (GBS) and chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). In children subacute inflammatory demyelinating polyradiculoneuropathy is included in CIDP. Immune polyradiculoneuropathies are not exclusively demyelinating, and axonal forms also responding favourably to immunotherapy occur. Evidence-based data on efficacy of therapy in children is lacking, relying on retrospective data, open label studies on small numbers of children, and mainly adult derived data. Immunotherapy (intravenous human immunoglobulin [IVIg] and plasmapheresis) shortens GBS recovery time with most children recovering completely. Childhood CIDP usually responds to corticosteroids and slow tapering is required to prevent relapses. IVIg and plasmapheresis are also effective. CIDP children resistant to steroids, IVIg, and steroid-dependent patients present a therapeutic challenge. Immunosuppressive agents including methotrexate, azathioprine and cyclosporine are helpful in some cases. Anecdotal reports of treatment with interferons alpha or beta and monoclonal antibodies against specific B-cell antigens (Rituximab, Alemtuzumab) have been described in limited case reports. Childhood CIDP prognosis is mostly favourable. However, a proportion of cases have residual neurological deficit.

Association of anti-GM1 antibodies but not of anti-cytomegalovirus, Campylobacter jejuni and Helicobacter pylori IgG, with a poor outcome in Guillain-Barré syndrome

Few reports exist on the influence of humoral immune responses, against microorganisms involved in infections preceding Guillain-Barré syndrome (GBS) and GM1, on clinical outcome. Nor is there any data on the relation between anti-Helicobacter pylori antibodies and prognosis in patients with GBS. To address these questions, we assayed and correlated serum anti-GM1 IgG and IgM and anti-H. pylori, anti-Campylobacter jejuni and anti-cytomegalovirus (CMV) IgG with duration of hospitalization of GBS patients and prognosis at discharge. Patients with anti-GM1 alone or associated with anti-H. pylori antibodies had significant longer hospitalization to reach a low clinical score at discharge than those without (P=0.004). A significant difference was also found for the association of anti-GM1 with anti-CMV antibodies (P=0.019). A weak but significant association of anti-GM1 and anti-C. jejuni antibodies with long hospitalization and worse prognosis at discharge was also found (P=0.02). The statistical significance increased when patients with anti-GM1 and anti-microorganism antibodies were compared with those displaying anti-H. pylori or anti-CMV only. These findings provide further evidence that the level of circulating anti-GM1 IgG plays a role in determining recovery from disability in GBS patients irrespective of other IgG against microorganisms causing infections preceding GBS.

Recent studies on the roles of antiglycosphingolipids in the pathogenesis of neurological disorders

Evidence is mounting to suggest a causal role of humoral immunity arising from antiglycosphingolipid (GSL) antibodies in a variety of neurological disorders. These disorders include the demyelinating and axonal forms of Guillain-Barre syndrome, multifocal motor neuropathy, chronic inflammatory demyelinating polyradiculoneuropathy, and IgM paraproteinemia. Many claims have been made regarding other neurological disorders, which should be carefully scrutinized for their validity, based on several criteria proposed in this review. These criteria include 1) characterization of the causative antigens and immunoglobulins, 2) correlation of the pathological lesions and clinical manifestation of the antigens, 3) establishment of animal models using pure GSLs as the antigens, 4) immunopathogenic mechanisms of the neurodenerative process, 5) mechanisms for the malfunctioning of blood-nerve barrier and the ensuing leakage of circulating antibodies into peripheral nerve parenchyma, and 6) the roles of anti-GSL antibodies that may cause humorally mediated nerve dysfunction and injury as well as interference with ion channel function at the node of Ranvier, where carbohydrate epitopes are located. Finally, the origin of the anti-GSL antibodies is discussed in light of the recent circumstantial evidence pointing to a molecular mimicry mechanism with infectious agents. With a better understanding of the immunopathogenic mechanisms, it will then be possible to devise rational and effective diagnostic and therapeutic strategies for the treatment of these neurological disorders.

Autoimmune diseases and Helicobacter pylori infection

In the last few years several studies have been performed on the association between H. pylori infection and a miscellany of extragastric disorders which also include autoimmune diseases. In particular, emerging evidence seems to give a potential role for H. pylori in ischaemic heart disease via a cross mimicry between antibodies against heat shock protein 65 which are produced in the consequence of infection, but which are also expressed in atherosclerotic lesions. In cases of healing of Sjogren syndrome and Schonlein-Henoch, purpura have also been reported. A recent study, moreover, showed that eradication of H. pylori infection may be effective in the disappearance of autoimmune thrombocytopenia. Finally, a role for H. pylori has also been postulated in other autoimmune diseases such as membranous nephropathy and some acute immune polyneuropathies. The mechanisms behind these clinical observations still remain unclear. However, if confirmed, these findings could revise the diagnostic and therapeutic approach to diseases previously considered as idiopathics.