Coincident membranous glomerulonephritis and chronic inflammatory demyelinating polyradiculoneuropathy: Questioning the autoimmunity hypothesis

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and membranous glomerulonephritis (MGN) are both autoimmune disorders that are rarely observed concurrently. We describe a patient who developed MGN nearly 20 years after the onset of CIDP, resulting in a secondary progression of his neuropathy. He responded dramatically to a novel regimen of plasma exchange and methotrexate. We propose a mechanism other than autoimmunity for the coincidence of these disorders and discuss the theoretical superiority of the treatment regimen that he received.

Anti-tissue transglutaminase IgA antibodies in peripheral neuropathy and motor neuronopathy

OBJECTIVES

The aim of the study was to investigate the occurence of anti-tissue transglutaminase antibodies (tTGA) in peripheral nerve disorders, and to correlate them with neurophysiologic findings and anti-glycolipid antibodies.

MATERIALS AND METHODS

We examined tTGA immunoglobulin-A serum level from 220 patients with polyneuropathy (acute inflammatory: n=90; chronic inflammatory: n=56; non-inflammatory: n=74) and 110 with motor neuron disease (MND).

RESULTS

Seven of the 330 neurologic patients (2.1%, six with polyneuropathy and one with MND) were positive for tTGA. Sixty-one of the 330 neurologic patients (18.4%) had slightly increased tTGA values compared with healthy controls. Increased tTGA values were associated with greater impairment of neurophysiologic findings, but not with the presence of anti-glycolipid antibodies.

CONCLUSIONS

We found a high prevalence of tTGA reactivity in patients with peripheral nerve disorders or MND. However, we were unable to demonstrate an increased risk of celiac disease in these diseases.

Fas-mediated T-cell apoptosis is impaired in patients with chronic inflammatory demyelinating polyneuropathy

The Fas death receptor is expressed by activated lymphocytes and is involved in switching-off the immune response. Its inherited defects cause auto-immune lymphoproliferative syndrome. Impaired Fas function may also play a role in other auto-immune diseases, such as multiple sclerosis and type 1 diabetes mellitus. The aim of this work was to evaluate Fas function in T cells from patients with chronic inflammatory demyelinating polyneuropathy (CIDP). We evaluated Fas-induced apoptosis in T-cell lines from 27 patients with CIDP, 12 patients with acute inflammatory demyelinating polyneuropathy (AIDP), and 110 controls. CIDP patients displayed lower Fas function than both AIDP patients and controls, whereas no statistically significant difference was found between AIDP patients and controls. Moreover, Fas function was lower in CIDP patients with progressive course than in those with relapsing-remitting course and lower in CIDP patients with axonal damage than in those with pure demyelination. These data suggest that defective Fas function favours CIDP development and aggressive evolution.

Diagnosis and treatment of chronic inflammatory demyelinating polyneuropathy

Chronic inflammatory demyelinating polyneuropathy (CIDP) is an immune-mediated acquired polyneuropathy that may lead to disability. CIDP is characterized by an autoimmune attack against peripheral nervous system myelin, by cellular and humoral mechanisms. Early diagnosis and treatment may yield better functional recovery, probably by minimizing secondary axonal loss from a primary demyelinating insult. Intravenous immunoglobulin and plasmapheresis are considered standard-of-care therapy in CIDP, based on randomized, double-blinded, placebo-controlled evidence. Corticosteroids, despite less robust evidence, are also considered standard therapy for CIDP. Other nonstandard therapies may work in refractory patients. These include azathioprine, cyclophosphamide, cyclosporine A, etanercept, interferon-alpha 2a, mycophenolate mofetil, and tacrolimus. Emerging therapies include interferon-beta 1a, rituximab, and high-dose cyclophosphamide without stem-cell rescue. Because most patients will require prolonged therapy, long-term side effects are important considerations.

Treatment of chronic inflammatory demyelinating polyneuropathy

PURPOSE OF REVIEW

Chronic inflammatory demyelinating poly(radiculo)neuropathy (CIDP) is a treatable disorder. There are three proven effective treatments available. Randomized controlled trials have only focused on short-term effects, but most patients need long-term therapy. The most up-to-date treatment options are discussed. Attention is also paid to the use of appropriate assessment scales and treatment of residual findings.

RECENT FINDINGS

A Cochrane review is available indicating that intravenous immunoglobulin is an effective treatment. Equal efficacy of intravenous immunoglobulin and steroids was shown during a 6-week treatment period. New open studies indicated possible efficacy for mycophenolate, interferon-beta and etanercept. Combinations of treatment are scarcely studied yet. Some CIDP patients may have a more acute onset of disease since maximum severity is reached within 4-8 weeks, resulting in confusion about the diagnosis. It was shown that severe fatigue can be a major complaint in CIDP patients; a training regimen might partially resolve these problems.

SUMMARY

CIDP is a treatable disorder, but most patients need long-term treatment. Intravenous immunoglobulin, steroids and plasma exchange are shown to be effective. It is suggested that other immunomodulatory agents can also be effective, but randomized trials are needed to confirm these benefits. General measures to rehabilitate patients and to manage symptoms like fatigue and other residual findings are important.

Treatment of Guillain-Barre syndrome and CIDP

Guillain-Barré syndrome (GBS) and chronic inflammatory demyelinating poly-(radiculo)neuropathy (CIDP) are immune-mediated disorders with a variable duration of progression and a range in severity of weakness. Infections can trigger GBS and exacerbate CIDP. Anti-ganglioside antibodies are important, but there is debate on the role of genetic factors in the pathogenesis of these disorders. Randomized controlled trials (RCT) have shown that intravenous immunoglobulin (IVIg) and plasma exchange (PE) are effective in both GBS and CIDP. Most CIDP patients also improve after steroid therapy. Despite current treatment options, many patients have residual deficits or need to be treated for a long period of time. Therefore, new treatment trials are highly indicated. This review focuses on the current and possible new treatment options that could be guided by recent results from laboratory experiments.

Advances in understanding and treatment of immune-mediated disorders of the peripheral nervous system

During recent years, novel insights in basic immunology and advances in biotechnology have contributed to an increased understanding of the pathogenetic mechanisms of immune-mediated disorders of the peripheral nervous system. This increased knowledge has an impact on the management of patients with this class of disorders. Current advances are outlined and their implication for therapeutic approaches addressed. As a prototypic immune-mediated neuropathy, special emphasis is placed on the pathogenesis and treatment of the Guillain-Barré syndrome and its variants. Moreover, neuropathies of the chronic inflammatory demyelinating, multifocal motor, and nonsystemic vasculitic types are discussed. This review summarizes recent progress with currently available therapies and--on the basis of present immunopathogenetic concepts--outlines future treatment strategies.